bluuebunny/crossref_metadata_2025_split huggingface dataset:
Peripherally induced human regulatory T cells uncouple Kv1.3 activation from TCR‐associated signaling
Authors: Reneer Mary C. , Estes Daniel J. , Vélez‐Ortega Alejandra C. , Norris Andrea , Mayer Michael , Marti Francesc 
Published: August 2011

AbstractPeripherally induced Tregs (iTregs) are being recognized as a functional and physiologically relevant T‐cell subset. Understanding the molecular basis of their development is a necessary step before the therapeutic potential of iTreg manipulation can be exploited. In this study, we report that the differentiation of primary human T cells to suppressor iTregs involves the relocation of key proximal TCR signaling elements to the highly active IL‐2‐Receptor (IL‐2‐R) pathway. In addition to the recruitment of lymphocyte‐specific protein tyrosine kinase (Lck) to the IL‐2‐R complex, we identified the dissociation of the voltage‐gated K+ channel Kv1.3 from the TCR pathway and its functional coupling to the IL‐2‐R. The regulatory switch of Kv1.3 activity in iTregs may constitute an important contributing factor in the signaling rewiring associated with the development of peripheral human iTregs and sheds new light upon the reciprocal crosstalk between the TCR and the IL‐2‐R pathways.
Simple and Efficient: Ethylene Glycol Isonitrile Gold(I) Chlorides for the Formation and Stabilization of Gold Nanoparticles
Authors: Tuchscherer André , Schaarschmidt Dieter , Schulze Steffen , Hietschold Michael , Lang Heinrich 
Published: August 2011

AbstractEthylene glycol isonitriles C≡N(CH2CH2O)nCH3 (5a, n = 1; 5b, n = 3; 5c, n = 4) with different chain lengths were prepared by using straightforward synthesis methodologies including the Gabriel synthesis and an Appel‐type reaction protocol. Upon treatment with [AuCl(SMe)2], compounds 5a–c gave the corresponding isocyanide gold(I) chlorides [AuCl{C≡N(CH2CH2O)nCH3}] (7a, n = 1; 7b, n = 3; 7c, n = 4). Single‐crystal X‐ray diffraction studies reveal a polymeric (7a) or dimeric (7c) structure with aurophilic interactions. Gold(I) complexes 7a–c were applied in the formation and stabilization of gold nanoparticles (AuNPs). The isonitriles with their ethylene glycol functionalities, which provide multiple donating capabilities, are able to stabilize the encapsulated gold colloids. The reduction of 7a–c by the addition of Na[BH4] in tetrahydrofuran or methanol produces AuNPs without the further addition of any stabilizer, since metal‐organic 7a–c combine the stabilizing component and gold source in one molecule. The dependency of different solvents, concentrations, and varying ethylene glycol chain lengths on the NP size and size distribution is reported. Characterization by TEM, UV/Vis spectroscopy, and XRPD revealed that AuNPs are formed with a size between 6.4(±1.4) to 9.5(±2.3) nm in methanol and 18.2(±2.3) to 27.2(±3.5) nm in tetrahydrofuran.
Carbon‐to‐Carbon Anion Relay Chemistry: Facile Generation of Substituted Allyllithium Species
Authors: Zheng Pinguan , Cai Zhengxin , Garimallaprabhakaran Aswinkumar , Rooshenas Parham , Schreiner Peter R. , Harmata Michael 
Published: August 2011

AbstractTreatment of [2‐(2‐bromophenyl)allyl]trimethylsilane with tBuLi in THF at –78 °C resulted in the rapid migration of the trimethylsilyl group to afford an allylic organolithium that can be easily trapped by a wide range of electrophiles. This is a rare example of a synthetically useful and efficientcarbon‐to‐carbon migration of a silicon group and represents a new approach to allylic organolithium species using anion relay chemistry.
Preparation and Properties of Reference Electrodes Based on Silver Paste Amalgam
Authors: Yosypchuk Bogdan , Barek Jiří , Yosypchuk Oksana 
Published: August 2011

AbstractThe preparation and testing of saturated calomel electrodes (SCE‐AgPA), mercury‐mercurous sulfate (MMSE‐AgPA) and mercury‐mercuric oxide (MMOE‐AgPA) reference electrodes based on silver paste amalgam are described. All three electrodes have shown long‐term stability of their potentials (ESCE‐AgPA=−0.56±0.34 mV; EMMSE‐AgPA=391.5±1.4 mV; EMMOE‐AgPA=−104.9±0.7 mV vs. classical SCE; test time was 14 months). All paste amalgam electrodes have potentials close to their analogues with metallic mercury. They can therefore replace each other without any recalculation. Peak potentials of anodic dissolution of cadmium measured with the SCE‐AgPA and SCE are identical. The greatest resistance to polarization was registered with the SCE‐AgPA and significantly lower with other tested electrodes.
Sensitive Electrochemical Sensor for Determination of Methyldopa Based on Polypyrrole/Carbon Nanoparticle Composite Thin Film Made by In Situ Electropolymerization
Authors: Shahrokhian Saeed , Saberi Reyhaneh‐Sadat , Kamalzadeh Zahra 
Published: August 2011

AbstractA composite surface coating is prepared by electropolymerization of a mixture of pyrrole and carbon nanoparticles onto a glassy carbon electrode (GCE). The microscopic structure and morphology of the composite film is characterized by scanning electron microscopy. The modified electrode offers a considerable improvement in voltammetric sensitivity toward methyldopa (m‐dopa), compared to the bare and polypyrrole‐coated GCEs. A significantly enhanced anodic peak current together with a remarkable increase in sharpness of the cyclic voltammetric (CV) signals are observed for the detection of m‐dopa. The effect of experimental parameters, such as scan rate and pH, are investigated by monitoring CV responses toward m‐dopa. It is found that a maximum current response can be obtained at pH 3.0 under a diffusion controlled process. A wide linear dynamic range (0.2–50 µM) with a detection limit of 60 nM is achieved for m‐dopa. The excellent response characteristics, e.g., high sensitivity, very good repeatability and reproducibility, and low detection limit, have made the prepared sensor suitable for the analysis of m‐dopa in pharmaceutical and clinical preparations.
Catalytic Adsorptive Stripping Chronopotentiometric Determination of Hexavalent Chromium at a Silver Amalgam Film Electrode of Prolonged Application
Authors: Bobrowski Andrzej , Kapturski Paweł , Zarębski Jerzy 
Published: August 2011

AbstractThe paper reports on the application of stripping chronopotentiometry for the determination of chromium(VI) at a silver‐based amalgam film electrode. It is the first attempt to apply such a detection system for the speciation of chromium. The procedure utilized catalytic reduction of nitrate ions induced by the instantaneous chromium(III)‐DTPA complex, accumulated at the electrode surface. The chronopotentiometric step is realized in the constant current mode. Several key parameters, such as the deposition potential, deposition time, nitrate concentration and stripping current were optimized. The detection limit obtained for 15 s of accumulation time was estimated at 0.025 µg/L. The repeatability of the signal was 6.1 %.
Amperometric Sensing Based on Glutathione Protected Au25 Nanoparticles and Their pH Dependent Electrocatalytic Activity
Authors: Kumar S. Senthil , Kwak Kyuju , Lee Dongil 
Published: August 2011

AbstractWe report here the electrochemical behavior of quantum sized glutathione protected Au25 nanoclusters and their use in electrochemical sensing. The Au25 modified electrode was found to show excellent electrocatalytic activity towards the oxidation of ascorbic acid and dopamine over a wide linear range from 0.71 to 44.4 µM. The modified electrode exhibited pH dependent electrocatalytic activity, which was attributed to the consequence of electrostatic attraction/repulsion between the charged Au25 clusters and the charged analytes at different pH. This result demonstrates the feasibility of enhancing the sensing selectivity among the charged analytes by controlling the charges on the clusters.
Standardized Characterization of a Flow Through Microbial Fuel Cell
Authors: Higgins Scott R. , Lau Carolin , Atanassov Plamen , Minteer Shelley D. , Cooney Michael J. 
Published: August 2011

AbstractMicrobial fuel cell research is a relatively new and fast growing field of interdisciplinary effort that has drawn scientists from several disparate disciplines. Consequently, establishing a “common language” regarding the “means and ways” of experimental preparation, data collection and characterization to obtain accurate and comparable figures of merit (describing microbial fuel cell performance) has proven difficult. We present a methodology for comprehensive engineering analysis from inoculation through batch, fed‐batch and finally continuous flow operation, and detail how a modified stack cell design complements this. More, our cell is able to operate near the thermodynamic maximum potential for oxidation of lactate.
Development of an Electrochemical Biosensor for the Rapid Detection of Cholera Toxin Using Air Stable Lipid Films with incorporated Ganglioside GM1
Authors: Nikoleli Georgia‐Paraskevi , Nikolelis Dimitrios P. , Tzamtzis Nikolaos 
Published: August 2011

AbstractThe present work describes the investigations of electrochemical interactions of cholera toxin with stabilized lipid films supported on a methacrylate polymer on a glass fiber filter with incorporated ganglioside GM1 for the development of a biosensor for cholera toxin. The analyte was injected into the flowing streams of a carrier electrolyte solution, the flow of the solution stops for 5 min and an ion current transient was obtained, the magnitude of which is correlated to the toxin concentration with detection limits of 0.06 µM. The method was applied in blood serum samples. Further work is directed to the rapid detection of other toxins used in bioterrorism using this novel ultrathin film technology.
Joint channel‐network coding strategies for networks with low‐complexity relays
Authors: Johnson Sarah J. , Ong Lawrence , Kellett Christopher M. 
Published: August 2011

ABSTRACTWe investigate joint network and channel coding schemes for networks when relay nodes are not capable of performing channel coding operations. Rather, channel encoding is performed at the source node, whereas channel decoding is carried out only at the destination nodes. We examine three different decoding strategies: independent network‐then‐channel decoding, serial network and channel decoding, and joint network and channel decoding. Furthermore, we describe how to implement such joint network and channel decoding using iteratively decodable error correction codes. Using simple networks as a model, we derive achievable rate regions and use simulations to demonstrate the effectiveness of the three decoders. Copyright © 2011 John Wiley & Sons, Ltd.
Effects of bilirubin and sera from jaundiced patients on osteoblasts: Contribution to the development of osteoporosis in liver diseases
Authors: Ruiz-Gaspà Silvia , Martinez-Ferrer Angels , Guañabens Nuria , Dubreuil Marta , Peris Pilar , Enjuanes Anna , de Osaba Maria Jesús Martinez , Alvarez Luisa , Monegal Ana , Combalia Andrés , Parés Albert 
Published: August 2011

Abstract

Low bone formation is considered to be the main feature in osteoporosis associated with cholestatic and end-stage liver diseases, although the consequences of retained substances in chronic cholestasis on bone cells have scarcely been studied. Therefore, we analyzed the effects of bilirubin and serum from jaundiced patients on viability, differentiation, mineralization, and gene expression in the cells involved in bone formation. The experiments were performed in human primary osteoblasts and SAOS-2 human osteosarcoma cells. Unconjugated bilirubin or serum from jaundiced patients resulted in a dose-dependent decrease in osteoblast viability. Concentrations of bilirubin or jaundiced serum without effects on cell survival significantly diminished osteoblast differentiation. Mineralization was significantly reduced by exposure to 50 μM bilirubin at all time points (from −32% to −55%) and jaundiced sera resulted in a significant decrease on cell mineralization as well. Furthermore, bilirubin down-regulated

RUNX2

(runt-related transcription factor 2) gene expression, a basic osteogenic factor involved in osteoblast differentiation, and serum from jaundiced patients significantly up-regulated the

RANKL/OPG

(receptor activator of nuclear factor-κB ligand/osteoprotegerin) gene expression ratio, a system closely involved in osteoblast-induced osteoclastogenesis.

Conclusion:

Besides decreased cell viability, unconjugated bilirubin and serum from jaundiced patients led to defective consequences on osteoblasts. Moreover, jaundiced serum up-regulates the system involved in osteoblast-induced osteoclastogenesis. These results support the deleterious consequences of increased bilirubin in advanced chronic cholestasis and in end-stage liver diseases, resulting in disturbed bone formation related to osteoblast dysfunction. (Hepatology 2011)
A polymorphism that delays fibrosis in hepatitis C promotes alternative splicing of AZIN1 , reducing fibrogenesis
Authors: Paris Andrew J. , Snapir Zohar , Christopherson Cindy D. , Kwok Shirley Y. , Lee Ursula E. , Ghiassi-Nejad Zahra , Kocabayoglu Peri , Sninsky John J. , Llovet Josep M. , Kahana Chaim , Friedman Scott L. 
Published: August 2011

Abstract

Among several single-nucleotide polymorphisms (SNPs) that correlate with fibrosis progression in chronic HCV, an SNP in the antizyme inhibitor (AzI) gene is most strongly associated with slow fibrosis progression. Our aim was to identify the mechanism(s) underlying this observation by exploring the impact of the AzI SNP on hepatic stellate cell (HSC) activity. Seven novel AZIN1 splice variants (“SV2-8”) were cloned by polymerase chain reaction from the LX2 human HSC line. Expression of a minigene in LX2 containing the

AZIN1

slow-fibrosis SNP yielded a 1.67-fold increase in AZIN1 splice variant 2 (AZIN1 SV2) messenger RNA (mRNA) (

P

= 0.05). In healthy human leukocytes, the SNP variant also correlated with significantly increased SV2 mRNA. Cells (293T) transfected with short hairpin RNA (shRNA) complementary to the exonic splicing chaperone SRp40 expressed 30% less SRp40 (

P

= 0.044) and 43% more AzI SV2 (

P

= 0.021) than control shRNA-expressing cells, mimicking the effect of the sequence variant. LX2 cells transfected with

AZIN1

full-length complementary DNA expressed 35% less collagen I mRNA (

P

= 0.09) and 18% less α-smooth muscle actin mRNA (

P

= 0.09). Transient transfection of AZIN1 SV2 complementary DNA into LX2 cells reduced collagen I gene expression by 64% (

P

= 0.001) and α-smooth muscle actin by 43% (

P

= 0.005) compared to vector-transfected controls, paralleling changes in protein expression. Both AZIN1 and AZIN-SV2 mRNAs are detectable in normal human liver and reduced in HCV cirrhotic livers. The AZIN1-SV2 acts via a polyamine-independent pathway, as it neither interacts with antizyme nor affects the ability of AZIN1 lacking this variant to neutralize antizyme.

Conclusion:

An SNP variant in the

AZIN1

gene leads to enhanced generation of a novel alternative splice form that modifies the fibrogenic potential of HSCs. (Hepatology 2011)
Impact of seasonal variations in hydrological stresses and spatial variations in geologic conditions on a TCE plume at an industrial complex in Wonju, Korea
Authors: Yang Jae‐Ha , Lee Kang‐Kun , Clement T. Prabhakar 
Published: August 2011

AbstractSpatial and temporal variations in a trichloroethylene (TCE) plume at an industrial complex in Wonju, Korea, were examined based on hydrogeological data and seven rounds of groundwater quality data collected over a year. The site has considerable vertical heterogeneities; the top layer of soil is covered by impermeable paving material at several locations, followed by a series of reclaimed or residual soil layers, and with weathered rocks to the crystalline biotite granite at the bottom. Areal heterogeneity in the surface conditions plays an important role in controlling groundwater recharge. The heterogeneity structure is influenced by complex surface conditions paved with asphalt and concrete. Owing to the presence of limited recharge area and concentrated summer precipitation events, the effects of seasonal variations on groundwater hydraulics tend to diminish with distance from the recharge area. This result was established by analysing the influence of the contrasting surface recharge conditions between the near‐source zone and the far zone, and the seasonally concentrated precipitation on the transport patterns of a TCE plume. In addition, variations in the plume's downstream contaminant flux levels were also analysed along a transect line near the source zone. The results show that the general tendency of the TCE plume contaminant concentration and mass discharges were reproducible if we account for seasonal recharge variations and the associated changes in the groundwater level. During recharge events, the TCE concentration variations appear to be influenced by leaching of the residual dense non‐aqueous‐phase liquid (DNAPL) TCE trapped in the unsaturated zone. This result shows that seasonal variations in contaminant plume near the source zone is inevitable at this site, and that these variations indicate the presence of residual DNAPL at or above the water table, at least in some isolated locations. Copyright © 2011 John Wiley & Sons, Ltd.
Linking spatial patterns of perched groundwater storage and stormflow generation processes in a headwater forested catchment
Authors: Ali Geneviève A. , L'Heureux Caroline , Roy André G. , Turmel Marie‐Claude , Courchesne François 
Published: August 2011

AbstractThis study examined hydropedological patterns and storage–discharge relationships towards catchment process understanding at a small forested site, the Hermine (Laurentians, Quebec, Canada). The catchment is characterized by a steep surface topography and a shallow, irregular, low‐permeability soil layer (LPSL), thus offering two possible main hydrologic drivers for runoff generation and routing. Using spatially detailed topographic data of the soil surface and the LPSL, water table levels measured at 94 locations on 50 occasions were expressed as 5 perched groundwater (PGW) storage variables: (i) a binary index illustrating the presence/absence of surface water, (ii) a soil saturation deficit, (iii) a water table elevation above the LPSL, (iv) a classification of sites as being in a dry, filling or spilling subsurface depression, and (v) a water table elevation above an underlying filled subsurface depression. The most common proxies for PGW storage, namely the saturation deficit and the location of surface saturated areas, were least appropriate to portray the Hermine catchment dynamics. Patterns of PGW storage were initially important during a rainstorm to trigger a response at the outlet but then remained unchanged even though streamflows continued to increase up to a higher order of magnitude. Hydraulically limited water tables were shown to exist in some areas, thus hinting towards the coexistence of rapid lateral preferential flow and slower subsurface flow. Most importantly, discontinuous storage–discharge relationships at the point‐scale combined into continuous relationships at the catchment‐scale, a result which can be seen as an emergent property of the Hermine catchment. Copyright © 2011 John Wiley & Sons, Ltd.
The seismic signatures of the surge wave from the 2009 Xiaolin landslide‐dam breach in Taiwan
Authors: Feng Zheng‐yi 
Published: August 2011

AbstractThe catastrophic Xiaolin landslide occurred on 9 August 2009, after Typhoon Morakot struck Taiwan. This landslide formed a dam that subsequently breached, burying and flooding the village of Xiaolin. Seismic signals were induced by the landslide and dam breaching and recorded at the Jiaxian broadband seismic station in Taiwan. The time‐frequency spectra for the data from this station were analysed to extract the seismic characteristics of the landslide and to deduce the timing of processes associated with the landslide dam‐break flooding. The duration of the river blockage, the time of the dam breach, the duration of the surge wave and the mean speed of the surge wave were estimated, and the hydrological implications of the flood behaviour were interpreted. The spectral characteristics of the different stream discharges were also studied. Stream water level/discharge is closely related to the frequency of the seismic signals. The broadband stations are particularly useful for flood monitoring due to their ability to continuously record measurements and their high sensitivity. Copyright © 2011 John Wiley & Sons, Ltd.
Supramolecular Assembly and Binding in Aqueous Solution: Useful Tips Regarding the Hofmeister and Hydrophobic Effects
Authors: Gibb Bruce C. 
Published: August 2011

AbstractThe self‐assembly of structurally discrete entities, and supramolecular chemistry in general, continues to expand into the aqueous realm. To do so, however, requires a firm understanding of the properties of aqueous solution, and how these “change the rules” for binding and assembly relative to organic solvents. In this mini‐review we highlight the state‐of‐the‐art understanding of the supramolecular properties of water, and how these influence the design of hosts and self‐assembling systems.
Accurate prediction of the enthalpies of formation for xanthophylls
Authors: Lii Jenn‐Huei , Liao Fu‐Xing , Hu Ching‐Han 
Published: August 2011

AbstractThis study investigates the applications of computational approaches in the prediction of enthalpies of formation (ΔHf) for C‐, H‐, and O‐containing compounds. Molecular mechanics (MM4) molecular mechanics method, density functional theory (DFT) combined with the atomic equivalent (AE) and group equivalent (GE) schemes, and DFT‐based correlation corrected atomization (CCAZ) were used. We emphasized on the application to xanthophylls, C‐, H‐, and O‐containing carotenoids which consist of ∼ 100 atoms and extended π‐delocaization systems. Within the training set, MM4 predictions are more accurate than those obtained using AE and GE; however a systematic underestimation was observed in the extended systems. ΔHf for the training set molecules predicted by CCAZ combined with DFT are in very good agreement with the G3 results. The average absolute deviations (AADs) of CCAZ combined with B3LYP and MPWB1K are 0.38 and 0.53 kcal/mol compared with the G3 data, and are 0.74 and 0.69 kcal/mol compared with the available experimental data, respectively. Consistency of the CCAZ approach for the selected xanthophylls is revealed by the AAD of 2.68 kcal/mol between B3LYP‐CCAZ and MPWB1K‐CCAZ. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011