bluuebunny/crossref_metadata_2025_split huggingface dataset:
Re-Examination of CD91 Function in GRP94 (Glycoprotein 96) Surface Binding, Uptake, and Peptide Cross-Presentation
Authors: Jockheck-Clark Angela R. , Bowers Edith V. , Totonchy Mariam B. , Neubauer Julie , Pizzo Salvatore V. , Nicchitta Christopher V. 
Published: November 2010

Abstract
GRP94 (gp96)-peptide complexes can be internalized by APCs and their associated peptides cross-presented to yield activation of CD8+ T cells. Investigations into the identity (or identities) of GRP94 surface receptors have yielded conflicting results, particularly with respect to CD91 (LRP1), which has been proposed to be essential for GRP94 recognition and uptake. To assess CD91 function in GRP94 surface binding and endocytosis, these parameters were examined in mouse embryonic fibroblast (MEF) cell lines whose expression of CD91 was either reduced via RNA interference or eliminated by genetic disruption of the CD91 locus. Reduction or loss of CD91 expression abrogated the binding and uptake of receptor-associated protein, an established CD91 ligand. Surface binding and uptake of an N-terminal domain of GRP94 (GRP94.NTD) was unaffected. GRP94.NTD surface binding was markedly suppressed after treatment of MEF cell lines with heparin, sodium chlorate, or heparinase II, demonstrating that heparin sulfate proteoglycans can function in GRP94.NTD surface binding. The role of CD91 in the cross-presentation of GRP94-associated peptides was examined in the DC2.4 dendritic cell line. In DC2.4 cells, which express CD91, GRP94.NTD-peptide cross-presentation was insensitive to the CD91 ligands receptor-associated protein or activated α2-macroglobulin and occurred primarily via a fluid-phase, rather than receptor-mediated, uptake pathway. These data clarify conflicting data on CD91 function in GRP94 surface binding, endocytosis, and peptide cross-presentation and identify a role for heparin sulfate proteoglycans in GRP94 surface binding.
Superantigen-Induced Proliferation of Human CD4+CD25− T Cells Is Followed by a Switch to a Functional Regulatory Phenotype
Authors: Taylor Amanda L. , Llewelyn Martin J. 
Published: November 2010

Abstract
Bacterial superantigens are potent T cell activators. In humans they cause toxic shock and scarlet fever, and they are implicated in Kawasaki’s disease, autoimmunity, atopy, and sepsis. Their function remains unknown, but it may be to impair host immune responses increasing bacterial carriage and transmission. Regulatory (CD25+FOXP3+) T cells (Tregs) play a role in controlling inflammatory responses to infection. Approximately 2% of circulating T cells are naturally occurring Tregs (nTregs). Conventional Ag stimulation of naive FOXP3− T cells induces Ag-specific Tregs. Polyclonal T cell activation has been shown to produce non–Ag-specific Tregs. Because superantigens are unique among microbial virulence factors in their ability to trigger polyclonal T cell activation, we wanted to determine whether superantigen stimulation of T cells could induce non–Ag-specific Tregs. We assessed the effect of superantigen stimulation of human T cells on activation, regulatory markers, and cytokine production by flow cytometry and T cell suppression assays. Stimulation of PBMCs with staphylococcal exotoxin A and streptococcal pyrogenic exotoxins A and K/L resulted in dose-dependent FOXP3 expression. Characterization of this response for streptococcal pyrogenic exotoxin K/L confirmed its Vβ specificity, that CD25+FOXP3+ cells arose from CD25− T cells and required APCs. These cells had increased CTLA-4 and CD127 expression, typical of the recently described activated converted Treg-like cells, and exhibited functional suppressor activity comparable to nTregs. Superantigen-stimulated CD25+FOXP3+ T cells expressed IL-10 at lower superantigen concentrations than was required to trigger IFN-γ production. This study provides a mechanism for bacterial evasion of the immune response through the superantigen induction of Tregs.
Measurement of Myeloid Cell Immune Suppressive Activity
Authors: Dolcetti Luigi , Peranzoni Elisa , Bronte Vincenzo 
Published: November 2010

AbstractThis unit presents simple methods to assess the immunosuppressive properties of immunoregulatory cells of myeloid origin, such as myeloid‐derived suppressor cells (MDSCs), both in vitro and in vivo. These methods are general and could be adapted to test the impact of different suppressive populations on T cell activation, proliferation, and cytotoxic activity; moreover they could be useful to assess the influence exerted on immune suppressive pathways by genetic modifications, chemical inhibitors, and drugs. Curr. Protoc. Immunol. 91:14.17.1‐14.17.25. © 2010 by John Wiley & Sons, Inc.
DFT Study for a Series of Less‐Symmetrical Crown Ethers and Their Complexes with Alkali Metal Cations
Authors: Miao Yuan , Wang Xueye , Jin Xin , Yi Ling , Ren Cuihuan 
Published: November 2010

AbstractA series of ring‐contracted (14‐crown‐5, 17‐crown‐6) and ring‐enlarged (16‐crown‐5, 17‐crown‐5, 19‐crown‐6, 20‐crown‐6) crown ethers and their complexes with alkali‐metal cations Na+ and K+ had been explored using density functional theory (DFT) at B3LYP/6‐31G* level in order to reveal the effects of the methylene‐chain length in a crown ether. The nucleophilicity of all crown ethers had been investigated by the Fukui functions. The quantum chemistry parameters, such as the energy gap (ΔE), the highest occupied molecular orbital energy (EHOMO) and the lowest unoccupied molecular orbital energy (ELUMO) for less‐symmetrical crown ethers and symmetrical frameworks (15‐crown‐5, 18‐crown‐6) had been calculated. In addition, the thermodynamic energies of complexation reactions had also been studied. The results of the DFT calculations show that the methylene‐chain length plays an important role in determining the structure characters of the crown ethers and also strongly influences the properties of the ethers. Some of the calculated results are in a good agreement with the experimental values.
Convolutive Cyclic Voltammetry, Chronoamperometry and Chronopotentiometry Studies of C6Me6‐isocloso‐ruthenaborane Complex in Non‐aqueous Medium at a Glassy Carbon Electrode
Authors: Ghoneim M. Mohamed , El‐Hallag S. Ibrahim 
Published: November 2010

AbstractElectroreduction of the C6Me6‐isocloso‐ruthenaborane complex {(C6Me6)‐isocloso‐1‐RuB10H10} has been investigated using cyclic voltammetry, convolutive voltammetry, chronoamperometry and chronopotentiometry techniques at a glassy carbon electrode in 0.1 mol·L−1 tetrabutyl ammonium perchlorate dissolved in methylene chloride. The investigated complex has been reduced via the consumption of two sequential electrons leading to the formation of monoanion and dianion, respectively. The electrode reaction pathway and the electrochemical parameters of the investigated system were determined. The extracted electrochemical parameters were verified via digital simulation treatments. Diffusion coefficient and heterogeneous electron transfer kinetics of the {(C6Me6)‐isocloso‐1‐RuB10H10} complex at low temperature were studied and discussed.
Formation of Left‐handed Double Twisted Silica Nanoribbons
Authors: Chen Yuxia , Wang Sibing , Liu Xiaojuan , Li Yi , Li Baozong , Yang Yonggang 
Published: November 2010

AbstractLeft‐handed double twisted silica nanoribbons were prepared through a sol‐gel transcription approach in the mixtures of ethanol and water. The self‐assemblies of a chiral low‐molecular‐weight amphiphile served as the templates. The samples were characterized using X‐ray diffraction, transmission electron microscope and scanning electron microscope. These double twisted silica nanoribbons were several micrometers in length, 50 to 70 nm in wideness, about 15 nm in thickness. The silica nanoribbons can be prepared in a large scale.
Synthesis of Hollow‐flower‐ball‐like Cd4(OH)5Cl3 Using Microwave Irradiation Method
Authors: Peng Yin , Liu Shuhua , Yang Zihui 
Published: November 2010

AbstractNovel mesoporous hollow‐flower‐ball‐like Cd4Cl3(OH)5 was selectively synthesized using microwave‐irradiation process. The structure of the resultant Cd4Cl3(OH)5 was characterized by scanning electron microscopy (SEM), X‐ray powder diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and low temperature nitrogen sorption isotherms. The concentration of the reagents and the reaction time affect the formation of this hollow‐flower‐ball‐like structure of this complex. The formation of this interesting structure may be attributed to the self‐assembly of smaller inorganic building blocks during the crystallization process of Cd4(OH)5Cl3 crystals. The photocatalytic activity of as‐prepared Cd4(OH)5Cl3 was evaluated by the degradation of salicylic acid and 4‐chlorophenol in water under UV‐irradiation.
A New Sensor for Simultaneous Determination of Tyrosine and Dopamine Using Iron(III) Doped Zeolite Modified Carbon Paste Electrode
Authors: Babaei Ali , Zendehdel Mojgan , Khalilzadeh Balal , Abnosi Mohammad 
Published: November 2010

AbstractA new chemically modified electrode is constructed based on iron(III) doped zeolite modified carbon paste electrode (Fe3+Y/ZMCPE). The new sensor could be used for the simultaneous determination of the biologically important compounds dopamine (DA) and tyrosine (Tyr). The measurements are carried out using differential pulse voltammetric (DPV) method. The prepared modified electrode shows voltammetric responses of high sensitivity, selectivity and stability for DA and Tyr under optimal conditions, which makes it a suitable sensor for simultaneous trace detection of DA and Tyr in solution. Application of the DPV method demonstrates that in the Briton Robinson buffer solutions (pH=5) containing 50 µmol/L Tyr, there is a linear relationship between the oxidation peaks and the concentrations of DA over the range of 0.1–200 µmol/L, with a detection limit of 0.05 µmol/L (S/N=3). For Tyr a linear correlation between oxidation peak current and concentration of Tyr over the range of 0.5–200 µmol/L (containing 50 µmol/L DA), with a detection limit of 0.08 µmol/L is obtained. The analytical performances of this sensor are evaluated for the detection of DA and Tyr in human serum and a medicine.
Study on Production of Amino Acids from Bean Dregs by Hydrolysis in Sub‐critical Water
Authors: Zhu Guangyong , Zhu Xian , Fan Qi , Liu Xiaolei , Shen Yijing , Jiang Junhui 
Published: November 2010

AbstractThis study investigated the production of value‐added amino acids from bean dregs by hydrolysis in subcritical water. It was investigated that the effect of reaction temperature, reaction time and CO2 on amino acid concentration in the hydrolysates of bean dregs. The product of amino acid was determined by Amino Acid Analyzer. The results show that a variety of amino acids are produced. The concentrations of arginine, lysine and alanine were relatively high in the hydrolysate. Temperature and time have a great influence on the hydrolysis reaction. The effects of reaction temperature and time on concentration of different amino acids vary. The addition of carbon dioxide led to an increase in amino acid yield due to the acceleration of acid hydrolyzed catalysis steps. The highest yield of total amino acids is 22% (0.22 g/g of dry bean dregs) at 330°C and 30 min. This method may provide a practical and economical solution for the disposal of bean dregs wastes.
Highly Selective Aldol Condensation Using Amine‐functionalized SiO2‐Al2O3 Mixed‐oxide under Solvent‐free Condition
Authors: Abbaspourrad Alireza , Javad Kalbasi Roozbeh , Zamani Farzad 
Published: November 2010

AbstractA series of amine catalysts supported on mesoporous molecular sieves SiO2/Al2O3 with trimethoxysilylpropylamine [(CH3O)3Si(CH2)3NH2] loading varying from 3 mmol to 6 mmol were synthesized by impregnation method. The aldol condensation of various aromatic aldehydes and 1‐heptanal was used to test the acid‐base cooperativity of amine‐functionalized SiO2/Al2O3. The effects of solvent, reaction temperature, benzaldehyde to 1‐heptanal molar ratio, different supports (SiO2, Al2O3 and SiO2‐Al2O3), catalyst amount and recyclability of the catalyst were investigated. Sample containing 5 mmol amine loaded showed highest benzaldehyde conversion (100%) and selectivity (97%) for jasminaldehyde.
Increased IL‐17A secretion in response to Candida albicans in autoimmune polyendocrine syndrome type 1 and its animal model
Authors: Ahlgren Kerstin M. , Moretti Silvia , Lundgren Brita Ardesjö , Karlsson Iulia , Åhlin Erik , Norling Anna , Hallgren Åsa , Perheentupa Jaakko , Gustafsson Jan , Rorsman Fredrik , Crewther Pauline E. , Rönnelid Johan , Bensing Sophie , Scott Hamish S. , Kämpe Olle , Romani Luigina , Lobell Anna 
Published: November 2010

AbstractAutoimmune polyendocrine syndrome type 1 (APS‐1) is a multiorgan autoimmune disease caused by mutations in the autoimmune regulator (AIRE) gene. Chronic mucocutaneous candidiasis, hypoparathyroidism and adrenal failure are hallmarks of the disease. The critical mechanisms causing chronic mucocutaneous candidiasis in APS‐1 patients have not been identified although autoantibodies to cytokines are implicated in the pathogenesis. To investigate whether the Th reactivity to Candida albicans (C. albicans) and other stimuli was altered, we isolated PBMC from APS‐1 patients and matched healthy controls. The Th17 pathway was upregulated in response to C. albicans in APS‐1 patients, whereas the IL‐22 secretion was reduced. Autoantibodies against IL‐22, IL‐17A and IL‐17F were detected in sera from APS‐1 patients by immunoprecipitation. In addition, Aire‐deficient (Aire0/0) mice were much more susceptible than Aire+/+ mice to mucosal candidiasis and C. albicans‐induced Th17‐ and Th1‐cell responses were increased in Aire0/0 mice. Thus an excessive IL‐17A reactivity towards C. albicans was observed in APS‐1 patients and Aire0/0 mice.
Shortened Carbon Nanotubes as Enhanced Support for High‐performance Platinum Catalysts
Authors: Wu Y.‐N. , Liao S.‐J. , Su H.‐N. , Dang D. , Liu B. 
Published: November 2010

AbstractCarbon nanotubes (CNTs) were shortened from 5 to 15 μm to ca. 200 nm using ball milling with ethanol as the milling aid agent, and a platinum catalyst with these shortened carbon nanotubes (SCNTs) as the support was prepared by a high‐pressure colloidal method. It was found that this catalyst with SCNTs showed much higher activity than a platinum catalyst with normal CNTs as support; for methanol anodic oxidation, the activity of the Pt/SCNTs was 50% higher than that of the Pt/CNTs, and the Pt/SCNTs also showed higher activity for the cathodic reduction of oxygen. The Pt/SCNTs were characterised by X‐ray diffraction scanning and transmission electron microscropy. It is suggested that the significant performance enhancement when SCNTs are used as support might result from the generation of new surfaces and defects, the opening of closed nanotubes in the process of milling, higher platinum dispersion on the shortened nanotubes and the interaction of platinum nanoparticles with the SCNTs.
Studies of the growth, evolution, and self‐aggregation of β‐amyloid fibrils using tapping‐mode atomic force microscopy
Authors: Serem Wilson K. , Bett Cyrus K. , Ngunjiri Johnpeter N. , Garno Jayne C. 
Published: November 2010

AbstractAmyloid peptide (Aβ) is the major protein component of plaques found in Alzheimer's disease, and the aggregation of Aβ into oligomeric and fibrillic assemblies has been shown to be an early event of the disease pathway. Visualization of the progressive evolution of nanoscale changes in the morphology of Aβ oligomeric assemblies and amyloid fibrils has been accomplished ex situ using atomic force microscopy (AFM) in ambient conditions. In this report, the size and the shape of amyloid β1‐40fibrils, as well as the secondary organization into aggregate structures were monitored at different intervals over a period of 5 months. Characterizations with tapping‐mode AFM serve to minimize the strong adhesive forces between the probe and the sample to prevent damage or displacement of fragile fibrils. The early stages of Aβ growth showed a predominance of spherical seed structures, oligomeric assemblies, and protofibrils; however the size and density of fibrils progressively increased with time. Within a few days of incubation, linear assemblies and fibrils became apparent. Over extended time scales of up to 5 months, the fibrils formed dense ensembles spanning lengths of several microns, which exhibit interesting changes due to self‐organization of the fibrils into bundles or tangles. Detailed characterization of the Aβ assembly process at the nanoscale will help elucidate the role of Aβ in the pathology of Alzheimer's disease. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.
Extraction and isolation of catechins from tea
Authors: Vuong Quan V. , Golding John B. , Nguyen Minh , Roach Paul D. 
Published: November 2010

AbstractTea is a major source of catechins, which have become well known for their antioxidant potential. Numerous human, animal, and in vitro studies have linked tea catechins with prevention of certain types of cancers, reduction of the risks for obesity, diabetes, and cardiovascular disease, and improvement of the immune system. Tea catechins are widely used in various neutraceuticals, pharmaceuticals, and cosmetics for either enhancing product shelf‐life or for enhancing human health. Thus, the demand for catechins has increased considerably. Catechins have been extracted and isolated from tea leaves by numerous methods through several steps including: treatment of the tea leaves, extraction of catechins from teas into solvents, isolation of catechins from other extracted components, and drying the preparations to obtain catechin extracts in a powder form. This paper outlines the physical and chemical properties of the tea catechins and reviews the extraction steps of the various extraction methods, as a basis to improve and further develop the extraction and isolation of the tea catechins.
In vivo evaluation and proof of radiofrequency safety of a novel diagnostic MR‐electrophysiology catheter
Authors: Weiss Steffen , Wirtz Daniel , David Bernd , Krueger Sascha , Lips Oliver , Caulfield Dennis , Pedersen Steen Fjord , Bostock Julian , Razavi Reza , Schaeffter Tobias 
Published: November 2010

AbstractAn MR‐electrophysiology (EP) catheter is presented that provides full diagnostic EP functionality and a high level of radiofrequency safety achieved by custom‐designed transmission lines. Highly resistive wires transmit intracardiac electrograms and currents for intracardiac pacing. A transformer cable transmits the localization signal of a tip coil. Specific absorption rate simulations and temperature measurements at 1.5 T demonstrate that a wire resistance > 3 kΩ/m limits dielectric heating to a physiologically irrelevant level. Additional wires do not increase tip specific absorption rate significantly, which is important because some clinical catheters require up to 20 electrodes. It is further demonstrated that radiofrequency‐induced and pacing‐induced resistive heating of the wires is negligible under clinical conditions. The MR‐EP catheters provided uncompromised recording of electrograms and cardiac pacing in combination with a standard EP recorder in MR‐guided in vivo EP studies, and the tip coil enabled fast and robust catheter localization. In vivo temperature measurements during such a study did not detect any device‐related heating, which confirms the high level of safety of the catheter, whereas unacceptable heating was found with a standard EP catheter. The presented concept for the first time enables catheters with full diagnostic EP functionality and active tracking and at the same time a sufficient level of radiofrequency safety for MRI without specific absorption rate‐related limitations. Magn Reson Med, 2011. © 2010 Wiley‐Liss, Inc.
Fiber‐type dependence of stretch‐induced force enhancement in rat skeletal muscle
Authors: Ramsey Kathryn A. , Bakker Anthony J. , Pinniger Gavin J. 
Published: November 2010

AbstractWhen an active muscle is stretched, the force increases due to strain of contractile and noncontractile proteins. We examined this force enhancement in rat extensor digitorum longus (EDL) and soleus muscles, which differ in their composition of these proteins, and their susceptibility to damage. Small stretches were applied at different velocities during isometric contractions from which we quantified the velocity‐dependent contractile and velocity‐independent noncontractile contributions to force enhancement. Whereas the contractile contribution was significantly greater in soleus than EDL, the noncontractile force enhancement was significantly greater in EDL than soleus, and increased ≈6‐fold after damaging eccentric contractions. The increased contractile stiffness may be functionally beneficial in slow muscle, as resistance to lengthening is fundamental to maintaining posture. Following stretch‐induced muscle damage this capacity is compromised, leading to increased strain of noncontractile proteins that may facilitate the activation of signaling pathways involved in muscle adaptation to injury. Muscle Nerve 42: 769–777, 2010
Survey of MicroRNA expression in pediatric brain tumors
Authors: Birks Diane K. , Barton Valerie N. , Donson Andrew M. , Handler Michael H. , Vibhakar Rajeev , Foreman Nicholas K. 
Published: November 2010

AbstractBackgroundA better understanding of pediatric brain tumor biology is needed to assist in the development of less toxic therapies and to provide better markers for disease stratification. MicroRNAs (miRNA) may play a significant role in brain tumor biology. The present study provides an initial survey of miRNA expression in pediatric central nervous system (CNS) malignancies including atypical teratoid/rhabdoid tumor, ependymoma, glioblastoma, medulloblastoma, and pilocytic astrocytoma.ProcedureMicroRNA expression in pediatric brain tumors and normal tissue controls was examined by microarray. Three aberrantly expressed miRNAs were further studied in a larger cohort by quantitative real‐time PCR (qRT‐PCR).ResultsMicroRNA‐129, miR‐142‐5p, and miR‐25 were differentially expressed in every pediatric brain tumor type compared to normal tissue controls as measured by microarray. When further examined by qRT‐PCR, these miRNAs demonstrated differential expression that significantly correlated with the microarray findings. Distinctive miRNA expression profiles were also observed in the different pediatric brain tumor types.ConclusionsMicroRNAs are differentially expressed between pediatric CNS neoplasms and normal tissue suggesting that they may play a significant role in oncogenesis. A greater understanding of aberrant miRNA expression in pediatric brain tumors may aid in the development of novel therapies. The characterization of tumor‐specific miRNA signatures may aid in the discovery of biomarkers with diagnostic or prognostic utility. Pediatr Blood Cancer 2011;56:211–216. © 2010 Wiley‐Liss, Inc.
Investigation of stabilizer‐free dispersion polymerization process of styrene and maleic anhydride copolymer microspheres
Authors: Liang Pengzong , Meng Zhun , Jiang Zhanglin , Nie Jun , He Yong 
Published: November 2010

AbstractThe copolymer microspheres of styrene (St) and maleic anhydride (MA) were synthesized by stabilizer‐free dispersion polymerization, and the polymerization process was explored in detail. The results showed that the homopolymerization of St formed in initial polymerization period served as stabilizer, and reaction solvent of closer solubility parameter would benefit the stabilizer‐free dispersion polymerization. In addition, some principal factors affecting the microspheres size, such as reaction time, reaction temperature, monomer concentration, molar feed ratio, reaction media, and cosolvent, were investigated as well. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010