bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD6 attenuates early and late signaling events, setting thresholds for T‐cell activation
Authors: Oliveira Marta I. , Gonçalves Carine M. , Pinto Mafalda , Fabre Stéphanie , Santos Ana Mafalda , Lee Simon F. , Castro Mónica A. A. , Nunes Raquel J. , Barbosa Rita R. , Parnes Jane R. , Yu Chao , Davis Simon J. , Moreira Alexandra , Bismuth Georges , Carmo Alexandre M. 
Published: September 2011

AbstractThe T lineage glycoprotein CD6 is generally considered to be a costimulator of T‐cell activation. Here, we demonstrate that CD6 significantly reduces early and late T‐cell responses upon superantigen stimulation or TCR triggering by Abs. Measuring calcium mobilization in single cells responding to superantigen, we found that human T cells expressing rat CD6 react significantly less well compared with T cells not expressing the exogenous receptor. When the cytoplasmic domain of rat CD6 was removed, calcium responses were recovered, indicating that the inhibitory properties of CD6 are attributable to its cytoplasmic domain. Calcium responses, and also late indicators of T‐cell activation such as IL‐2 release, were also diminished in TCR‐activated Jurkat cells expressing human CD6, compared with CD6‐deficient cells or cells expressing a cytoplasmic deletion mutant of human CD6. Similarly, calcium signals triggered by anti‐CD3 were enhanced in human T lymphocytes following morpholino‐mediated suppression of CD6 expression. Finally, the proliferation of T lymphocytes was increased when the CD6–CD166 interaction was blocked with anti‐CD166 Abs, but inhibited when anti‐CD6 Abs were used. Our data suggest that CD6 is a signaling attenuator whose expression alone, i.e. in the absence of ligand engagement, is sufficient to restrain signaling in T cells.
Natural variations at position 93 of the invariant Vα24‐Jα18 α chain of human iNKT‐cell TCRs strongly impact on CD1d binding
Authors: Sanderson Joseph P. , Waldburger‐Hauri Kathrin , Garzón Diana , Matulis Gediminas , Mansour Salah , Pumphrey Nicholas J. , Lissin Nikolai , Villiger Peter M. , Jakobsen Bent , Faraldo‐Gómez José D. , Gadola Stephan D. 
Published: September 2011

AbstractHuman invariant natural killer T (NKT) cell TCRs bind to CD1d via an “invariant” Vα24‐Jα18 chain (iNKTα) paired to semi‐invariant Vβ11 chains (iNKTβ). Single‐amino acid variations at position 93 (p93) of iNKTα, immediately upstream of the “invariant” CDR3α region, have been reported in a substantial proportion of human iNKT‐cell clones (4–30%). Although p93, a serine in most human iNKT‐cell TCRs, makes no contact with CD1d, it could affect CD1d binding by altering the conformation of the crucial CDR3α loop. By generating recombinant refolded iNKT‐cell TCRs, we show that natural single‐nucleotide variations in iNKTα, translating to serine, threonine, asparagine or isoleucine at p93, exert a powerful effect on CD1d binding, with up to 28‐fold differences in affinity between these variants. This effect was observed with CD1d loaded with either the artificial α‐galactosylceramide antigens KRN7000 or OCH, or the endogenous glycolipid β‐galactosylceramide, and its importance for autoreactive recognition of endogenous lipids was demonstrated by the binding of variant iNKT‐cell TCR tetramers to cell surface expressed CD1d. The serine‐containing variant showed the strongest CD1d binding, offering an explanation for its predominance in vivo. Complementary molecular dynamics modeling studies were consistent with an impact of p93 on the conformation of the CDR3α loop.
Photophysical and Electrochemical Properties of Phenanthroline‐Based Bis‐cyclometallated Iridium Complexes in Aqueous and Organic Media
Authors: Kiran Reshmi V. , Hogan Conor F. , James Bruce D. , Wilson David J. D. 
Published: September 2011

AbstractThe electrochemical and photophysical properties of biscyclometallated iridium(III) complexes containing phenanthroline‐based ligands have been investigated and compared in organic and aqueous media. Complexes having general formula [Ir(ppy)2(N∩N)]+/– were synthesized, where ppy is the cyclometallating ligand, 2‐phenylpyridine, and N∩N represents one of the following phenanthroline based ligands: 1,10‐phenanthroline (phen), 4,7‐diphenyl‐1,10‐phenanthroline (dpp) and 4,7‐diphenyl‐1,10‐phenanthrolinedisulfonate (BPS). In the case of [Ir(ppy)2(BPS)]–, the SO3– group located on the phenyl ring of BPS dramatically increases the aqueous solubility of the complex compared to the dpp complex, which is only soluble in organic media. The chloride salt of the underivatized phen complex, though not as soluble as the BPS chelated complex, is sufficiently soluble (> 1 mM) for sensing and other applications in aqueous media. The electrochemical response depends markedly on the medium; all the complexes showed reversible behaviour in organic media, whereas the oxidative electrochemistry of [Ir(ppy)2BPS]– and [Ir(ppy)2phen]+ was irreversible. Results from spectroelectrochemical experiments indicate that electrolysis produces significant changes to the UV region of the spectrum associated with the ppy moieties. Significantly, this demonstrates that the highest occupied molecular orbital (HOMO) is not entirely metal based but is also associated with the cyclometallating ligand. The variation in emission maxima between the iridium complexes was small in organic and aqueous media, but the colour of the emission depends on solvent polarity and strongly on temperature. Most significantly, the quantum yields for these species are also strongly influenced by the solvent: high quantum yields, ranging from 14.0 to 28.6 %, are observed in CH2Cl2. However, in aqueous media the water‐soluble complexes, [Ir(ppy)2BPS]– and [Ir(ppy)2phen]+, exhibited significantly diminished quantum yields of 2.5 and 2.6 %, respectively. Theoretical calculations confirm the spectroscopic assignments and that the HOMO is significantly delocalized over the metal and cyclometallating ligands. The relationship between the electrochemical, spectroscopic and theoretical results is discussed.
Organochromium Complexes Bearing Noninnocent Diimine Ligands
Authors: Kreisel Kevin A. , Yap Glenn P. A. , Theopold Klaus H. 
Published: September 2011

AbstractWe have prepared several anionic and neutral organochromium complexes featuring noninnocent α‐diimine ligands. All neutral and anionic complexes refrain from insertion of the C=N bonds of the diimine ligand into the chromium–carbon bonds, presumably due to the reduced nature of the diimine ligand. However, insertion can be facilitated by one‐electron oxidation. Thus, oxidation of [(HLiPr)CrR(THF)] [HLiPr = Ar–N=C(H)–(H)C=N–Ar in which Ar = 2,6‐diisopropylphenyl and R = CH2SiMe3 or CH3] with [(C5H5)2Fe]+ presumably forms [(HLiPr)CrR(THF)]+, which contains a neutral diimine ligand coordinated to CrII. This cationic complex apparently undergoes immediate insertion of the C=N bond of the diimine ligand into the Cr–alkyl bond, followed by C–H activation of the isopropyl substituent of an N–aryl group on the diimine ligand. DFT calculations confirm that [(HLiPr)CrR(THF)]+ contains a neutral innocent diimine ligand that undergoes C=N bond insertion into the Cr–R bond.
Supramolecular Hydrogen‐Bonding Tautomeric Sulfonamido–Phosphinamides: A Perfect P‐Chirogenic Memory
Authors: Patureau Frederic W. , Siegler Maxime A. , Spek Anthony L. , Sandee Albertus J. , Jugé Sylvain , Aziz Sarwar , Berkessel Albrecht , Reek Joost N. H. 
Published: September 2011

AbstractP‐chirogenic, supramolecular hydrogen‐bonding C1‐symmetrical sulfonamido–phosphinamides (METAMORPhos) have been successfully prepared. They were all found to possess a characteristic prototropic equilibrium between the PIII and the PV tautomers that is slow on the NMR spectroscopic timescale. Despite the dynamic and reversible protonation of the P centre, the P‐chirogenic information was found to be retained in the tautomerization process, even in a protic solvent environment. Several strategies to access the corresponding enantiopure compounds were investigated, such as diastereoselective crystallization, or enantioselective synthesis. It was possible to resolve such a class of chiral ligands with up to 99 % ee, and apply them in the Rh‐catalyzed asymmetric hydrogenation of alkenes. These ligands are interesting new building blocks in the area of acid/base‐type noninnocent ligand catalysis.
Dysfunctional anticipatory thoughts and the self‐handicapping strategy
Authors: McCrea Sean M. , Flamm Aneka 
Published: September 2011

AbstractSelf‐handicapping is an anticipatory self‐protective strategy in which individuals create or claim obstacles to success prior to an important performance to excuse potential failure. The present research sought in four studies to document the anticipatory nature of self‐handicapping, examining the role of prefactual (“what if …?”) thoughts in this strategy. Individuals prone to self‐handicap were more likely to generate prefactuals, identifying ways to undermine their performance. Moreover, inducing individuals to consider these thoughts increased self‐handicapping behavior, whereas focusing individuals on ways to improve their performance actually reduced self‐handicapping behavior. Implications of this work for understanding the cognitive processes underlying self‐handicapping behavior and for interventions that seek to minimize this self‐defeating behavior are discussed. Copyright © 2011 John Wiley & Sons, Ltd.
Fe3+‐immobilized nanoparticle‐modified capillary for capillary electrophoretic separation of phosphoproteins and non‐phosphoproteins
Authors: Hu Qin , Hu Shaoqiang , Zhang Zhenyang , Zhou Ximin , Yang Shanshan , Zhang Yuan , Chen Xinguo 
Published: September 2011

AbstractA fused‐silica capillary modified with Fe3+‐immobilized magnetic nanoparticles (Fe3+‐IMAN) has been investigated for the capillary electrophoretic (CE) separation of phosphoproteins and non‐phosphoproteins. The Fe3+‐IMAN capillary was achieved by covalently immobilising epoxy‐based magnetic silica nanoparticles (160 nm) on the prederivatized 3‐aminopropyl‐trimethoxysilane (APTMS) fused‐silica capillary (75 μm id), followed by disodium iminodiacetate and Fe3+. The buildup process was examined by measuring the streaming potentials of the bare capillary, APTMS capillary, epoxy‐based nanoparticle capillary and Fe3+‐IMAN capillary by varying the buffer pH. An inverted fluorescence microscope was used to determine the surface features of the Fe3+‐IMAN capillary derivatized with morin. Further experimental results confirmed that Fe3+‐IMAN bonded on the inner wall of the APTMS capillary could provide sufficient solute‐bonded phase interactions to allow for the CE separation of phosphoproteins and non‐phosphoproteins at concentration levels down to 50 μg/mL. The highest number of theoretical plates obtained was about 233 000/m, and the relative standard deviation (RSD) for migration times was <2.57% for eight consecutive runs, respectively. Additionally, the Fe3+‐IMAN modifing method was also applied to the analyses of bovine milk proteins. With simplicity, high resolving power, and high repeatability, the proposed method has shown great potential for phosphoproteomics applications.
Regeneration of the heart
Authors: Steinhauser Matthew L. , Lee Richard T. 
Published: September 2011

AbstractThe death of cardiac myocytes diminishes the heart's pump function and is a major cause of heart failure, one of the dominant causes of death worldwide. Other than transplantation, there are no therapies that directly address the loss of cardiac myocytes, which explains the current excitement in cardiac regeneration. The field is evolving in two important directions. First, although endogenous mammalian cardiac regeneration clearly seems to decline rapidly after birth, it may still persist in adulthood. The careful elucidation of the cellular and molecular mechanisms of endogenous heart regeneration may therefore provide an opportunity for developing therapeutic interventions that amplify this process. Second, recent breakthroughs have enabled reprogramming of cells that were apparently terminally differentiated, either by dedifferentiation into pluripotent stem cells or by transdifferentiation into cardiac myocytes. These achievements challenge our conceptions of what is possible in terms of heart regeneration. In this review, we discuss the current status of research on cardiac regeneration, with a focus on the challenges that hold back therapeutic development.
Land subsidence along the Ionian coast of SE Sicily (Italy), detection and analysis via Small Baseline Subset (SBAS) multitemporal differential SAR interferometry
Authors: Canova Fabio , Tolomei Cristiano , Salvi Stefano , Toscani Giovanni , Seno Silvio 
Published: September 2011

ABSTRACTThe paper presents the results of a multi‐temporal, differential interferometric synthetic aperture radar (DInSAR) analysis aiming to identify active surface deformation phenomena in south‐eastern Sicily. The study area has been chosen because of its strong seismicity, high concentration of industrial and agricultural activities, and high density of people living in the coastal area. Furthermore, the morphology, lithology and climatic features of this sector of the Hyblean foreland are suitable for an interferometric analysis, providing a high coherence over the area. The Small BAseline Subset (SBAS) multitemporal DInSAR technique was used to calculate mean ground velocity maps and displacement time series from a large data set of European Remote Sensing Satellites (ERS 1–2) images spanning the time period 1992–2000. The reliability of the DInSAR results was tested calculating the EastSAR and UpSAR values over two permanent global positioning system (GPS) stations in the area, and comparing them with the EastGPS and UpGPS values. The residuals between GPS and DInSAR velocities were 1 and 0.6 mm/yr for the Up and East components, respectively. Four main subsiding areas, previously undetected, have been identified, corresponding with the towns of Augusta, Siracusa, Priolo, and Villasmundo. The observed deformation phenomena are located within coastal structural basins, filled with Pleistocene and Holocence deposits, except the Villasmundo land subsidence, which is located on the Hyblean plateau. The measured deformation rates reach values up to −18 mm/yr in Augusta, –6 mm/yr in Siracusa, –5 mm/yr in Villasmundo and −4.5 mm/yr in Priolo. The examination of velocity profiles, time series, and geological data allows us to relate all the detected deformation patterns primarily to groundwater over‐exploitation. A multi‐dimensional interpolation with kriging was performed to obtain a field subsidence map. A first‐order elastic deformation model was used to simulate the peculiar features of the Villasmundo subsidence. Copyright © 2011 John Wiley & Sons, Ltd.
Ecosystem functions and densities of contributing functional groups respond in a different way to chemical stress
Authors: De Laender Frederik , Taub Frieda B , Janssen Colin R 
Published: September 2011

Abstract
Understanding whether and to what extent ecosystem functions respond to chemicals is a major challenge in environmental toxicology. The available data gathered by ecosystem-level experiments (micro- and mesocosms) often describe the responses of taxa densities to stress. However, whether these responses are proportional to the responses of associated ecosystem functions to stress is unclear. By combining a carbon budget modeling technique with data from a standardized microcosm experiment with a known community composition, we quantified three ecosystem functions (net primary production [NPP], net mesozooplankton production [NZP], and net bacterial production [NBP]) at three Cu concentrations, with a control. Changes of these ecosystem functions with increasing chemical concentrations were not always proportional to the Cu effects on the densities of the contributing functional groups. For example, Cu treatments decreased mesozooplankton density by 100-fold and increased phytoplankton density 10- to 100-fold while increasing NZP and leaving NPP unaltered. However, in contrast, Cu affected microzooplankton and the associated function (NBP) in a comparable way. We illustrate that differences in the response of phytoplankton/mesozooplankton densities and the associated ecosystem functions to stress occur because functional rates (e.g., photosynthesis rates/ingestion rates) vary among Cu treatments and in time. These variations could be explained by food web ecology but not by direct Cu effects, indicating that ecology may be a useful basis for understanding environmental effects of stressors. Environ. Toxicol. Chem. 2011;30:2892–2898. © 2011 SETAC
Comparison of the parameter estimation methods of surge arresters using modified particle swarm optimization algorithm
Authors: Nafar M. , Gharehpetian G. B. , Niknam T. 
Published: September 2011

SUMMARYThe measurements show that the residual voltage of the metal oxide surge arrester (MOSA) has a dynamic characteristic. The accurate modeling and simulation of this dynamic characteristic is very important for arrester allocation, systems reliability, and insulation coordination studies. Several models with acceptable accuracy have been suggested to describe this behavior. It should be noted that the determination of nonlinear elements of MOSAs is very important for all models. In this article, a comparison among the different methods of the determination of the surge arrester voltage–current characteristics is represented. A new method, which is the combination of particle swarm optimization (PSO) and ant colony optimization methods, is proposed to estimate the parameters of MOSA models. In the proposed algorithm, to overcome the drawback of the PSO algorithm (convergence to local optima), to improve the global search capability, and to prevent the convergence to local minima, ant colony optimization algorithm is combined to PSO algorithm. The proposed method is called modified PSO. The transient models of MOSA have been simulated by using ATP‐EMTP. The results of simulations have been applied to the program, which is based on the modified PSO method and can determine the fitness and parameters of different models. The validity and the accuracy of the estimated parameters are assessed by comparing the predicted residual voltage with the experimental results. Copyright © 2011 John Wiley & Sons, Ltd.
Late effects of high‐dose adjuvant chemotherapy on white and gray matter in breast cancer survivors: Converging results from multimodal magnetic resonance imaging
Authors: de Ruiter Michiel B. , Reneman Liesbeth , Boogerd Willem , Veltman Dick J. , Caan Matthan , Douaud Gwenaëlle , Lavini Cristina , Linn Sabine C. , Boven Epie , van Dam Frits S.A.M. , Schagen Sanne B. 
Published: September 2011

AbstractThe neural substrate underlying cognitive impairments after chemotherapy is largely unknown. Here, we investigated very late (>9 years) effects of adjuvant high‐dose chemotherapy on brain white and gray matter in primary breast cancer survivors (n = 17) with multimodal magnetic resonance imaging (MRI). A group of breast cancer survivors who did not receive chemotherapy was scanned for comparison (n = 15). Neuropsychological tests demonstrated cognitive impairments in the chemotherapy group. Diffusion tensor imaging (DTI) with tract‐based spatial statistics showed that chemotherapy was associated with focal changes in DTI values indicative for reduced white matter integrity. Single voxel proton MR spectroscopy (1H‐MRS) in the left centrum semiovale (white matter) showed a reduction of N‐acetylasparate/creatine indicative of axonal injury. Voxel‐based morphometry demonstrated a reduction of gray matter volume that overlapped with fMRI hypoactivation (as reported in a previous publication) in posterior parietal areas and colocalized with DTI abnormalities. Also, DTI correlated with 1H‐MRS only in the chemotherapy group. These results converge to suggest that high‐dose adjuvant chemotherapy for breast cancer is associated with long‐term injury to white matter, presumably reflecting a combination of axonal degeneration and demyelination, and damage to gray matter with associated functional deficits. Hormonal treatment with tamoxifen may also have contributed to the observed effects, although results from other studies indicate that it is unlikely that tamoxifen is solely or largely responsible. Using this multimodality approach we provide for the first time insight into the neural substrate underlying cognitive impairments following systemic administration of cytotoxic agents many years after treatment. Hum Brain Mapp, 2012. © 2011 Wiley Periodicals, Inc.
Functional connectivity changes in multiple sclerosis patients: A graph analytical study of MEG resting state data
Authors: Schoonheim Menno M. , Geurts Jeroen J.G. , Landi Doriana , Douw Linda , van der Meer Marieke L. , Vrenken Hugo , Polman Chris H. , Barkhof Frederik , Stam Cornelis J. 
Published: September 2011

AbstractMultiple sclerosis (MS) is characterized by extensive damage in the central nervous system. Within this field, there is a strong need for more advanced, functional imaging measures, as abnormalities measured with structural imaging insufficiently explain clinicocognitive decline in MS. In this study we investigated functional connectivity changes in MS using resting‐state magnetoencephalography (MEG). Data from 34 MS patients and 28 age and gender‐matched controls was assessed using synchronization likelihood (SL) as a measure of functional interaction strength between brain regions, and graph analysis to characterize topological patterns of connectivity changes. Cognition was assessed using extensive neuropsychological evaluation. Structural measures included brain and lesion volumes, using MRI. Results show SL increases in MS patients in theta, lower alpha and beta bands, with decreases in the upper alpha band. Graph analysis revealed a more regular topology in the lower alpha band in patients, indicated by an increased path length (λ) and clustering coefficient (γ). Attention and working memory domains were impaired, with decreased brain volumes. A stepwise linear regression model using clinical, MRI and MEG parameters as predictors revealed that only increases in lower alpha band γ predicted impaired cognition. Cognitive impairments and related altered connectivity patterns were found to be especially predominant in male patients. These results show specific functional changes in MS as measured with MEG. Only changes in network topology were related to poorer cognitive outcome. This indicates the value of graph analysis beyond traditional structural and functional measures, with possible implications for diagnostic and/or prognostic purposes in MS. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.
Anti‐EGFR–targeting agents in recurrent or metastatic head and neck carcinoma: A meta‐analysis
Authors: Petrelli Fausto , Barni Sandro 
Published: September 2011

AbstractBackgroundAnti–epidermal growth factor receptor (EGFR) therapies are effective in head and neck carcinoma. A meta‐analysis was performed to assess their efficacy and safety in advanced head and neck carcinoma.MethodsSix trials randomizing 2257 patients with recurrent/metastatic head and neck carcinoma for chemotherapy or best supportive care with or without anti‐EGFR therapies were identified. The efficacy data included progression‐free survival (PFS), overall survival (OS), response rate, and toxicity.ResultsThe response rate was higher in the experimental arm (p < .0001; relative risk = 1.62). A significant PFS benefit (p < .0001; hazard ratio [HR] = 0.70) favored the anti‐EGFR treatment. Survival was significantly increased if trials of monoclonal antibodies were included (p = .004; HR = 0.83). A higher incidence of diarrhea, skin rash, anorexia, and hypomagnesemia was observed.ConclusionsThis meta‐analysis suggests that in recurrent/metastatic head and neck cancer the addition of anti‐EGFR monoclonal antibodies to standard therapy confers a statistically significant improvement in OS, PFS, and overall response rate. © 2011 Wiley Periodicals, Inc. Head Neck, 2011