bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study on Modern High Effective Random Packings for Ethanol‐Water Rectification
Authors: Darakchiev S. , Semkov K. 
Published: June 2008

AbstractRaschig Super‐Ring is a modern and high‐efficient packing used for intensification of absorption and distillation processes. The aim of this work is to characterize the efficiency of this packing applied to rectification of an important industrial system, ethanol‐water, and to compare its efficiency to that of some random packings of the third generation as well as to the structured packing, HOLPACK, which is used in the ethanol production industry. The experiments were carried out in a column installation, 0.213 m in diameter with a packing height of 2.8 m. The column is heated by a number of electrical heaters (total power 45 kW), which can be switched gradually. Operation at total and partial reflux is possible. Eight types of random packings were studied: five types of Raschig Super‐Ring, four metallic (with characteristic dimensions 0.5, 0.6, 0.7, and 1”) and one of plastic material 0.6”; two types of packing IMTP and one plastic Ralu Flow. Some experiments were conducted at total reflux operation at vapor velocity, 0.253–0.936 m/s, and liquid superficial velocity, 4.44 · 10–4–1.63 · 10–3 m3/(m2s). Experiments at partial reflux were carried out at constant liquid superficial velocity and changeable vapor velocity as well as at constant vapor velocity and changeable liquid velocity. The results are presented as height of transfer unit, HTU, and height equivalent to a theoretical plate, HETP, as a function of the velocity of phases.
Heat Exchanger Network synthesis with Detailed Heat Exchanger Design
Authors: Jin Z. L. , Qiwu D. , Minshan L. 
Published: June 2008

AbstractPressure drop and fouling are important issues in heat exchanger network synthesis, which are usually neglected. Heat exchangers were designed in detail during the heat exchanger network synthesis, and pressure drop and fouling effects were taken into account. Pinch analysis combined with exergoeconomic analysis was used for determining optimal minimum approach temperature (ΔTmin) for heat exchanger network synthesis. Exergy consumption of heat transfer in HENs was calculated using a subsection integral on balanced composite curves. The heat transfer coefficients of all heat exchangers in the network were calculated iteratively to meet the requirements of optimal area and allowable pressure drops. The proposed method was applied to an industrial case. Numerical results indicate the importance of the detailed design of heat exchangers in HENs synthesis.
Solution‐, Solid‐Phase, and Fluorous Synthesis of β,β‐Difluorinated Cyclic Quaternary α‐Amino Acid Derivatives: A Comparative Study
Authors: Fustero Santos , Sánchez‐Roselló María , Rodrigo Vanessa , Sanz‐Cervera Juan F. , Piera Julio , Simón‐Fuentes Antonio , del Pozo Carlos 
Published: June 2008

AbstractThe diastereoselective synthesis of cyclic β,β‐difluorinated α‐amino acid derivatives bearing a quaternary stereocenter is described. The process relies on the chemo‐ and diastereoselective addition of allylic organometallic reagents to fluorinated α‐imino esters and a subsequent ring‐closing metathesis reaction (RCM). Complete selectivity in the nucleophilic addition was achieved with (R)‐phenylglycinol methyl ether as a chiral auxiliary. The resulting amino acids were introduced into peptide chains, which could facilitate the preparation of potentially bioactive dipeptide derivatives. In addition, the solution synthesis of these cyclic fluorinated α‐amino acids was successfully adapted to solid‐phase and fluorous‐phase techniques. The reaction times and final deprotection were clearly more favorable in the latter, in which a fluorous trimethylsilylethanol (TMSE) tag was used. The tag was then easily removed upon treatment with TBAF in a high‐yield transesterification process.
Awakening dynamics via passive coupling and synchronization mechanism in oscillatory cellular neural/nonlinear networks
Authors: Szatmári István , Chua Leon O. 
Published: June 2008

AbstractWe have studied synchronization mechanism in locally coupled nonlinear oscillators. Here, synchronization takes place by passive coupling based on a reaction–diffusion process. We will compare this mechanism with basic synchronization techniques, showing their similarities and specific properties. In addition to synchronization, passive and local coupling can also ‘awaken’ non‐oscillating cell circuits and trigger oscillation, provided that cells are locally active. This result resembles Turing's and Smale's works showing that locally communicating simple elements can produce very different patterns even if separate elements do not show any activity. This property will be demonstrated for two second‐order cells and also for a large ensemble of oscillatory cells. In latter case, the network of oscillatory cells exhibits very sophisticated spatio‐temporal waves, e.g. spiral waves. Copyright © 2008 John Wiley & Sons, Ltd.
Functional dichotomy of plasmacytoid dendritic cells: Antigen‐specific activation of T cells versus production of type I interferon
Authors: Jaehn Peter S. , Zaenker Kurt S. , Schmitz Juergen , Dzionek Andrzej 
Published: June 2008

AbstractHuman plasmacytoid dendritic cells (PDC) are believed to link innate and adaptive immunity by producing type I interferon (IFN‐I) and triggering adaptive T cell‐mediated immunity. However, it remains elusive to which degree both PDC functions are linked. Here we show that CMV antigen targeted to PDC using a CD303 (blood dendritic cell antigen 2, BDCA‐2) mAb is rapidly endocytosed and traffics via early sorting endosomes to emerging MHC‐enriched compartments. Both processes occur independently of TLR ligand stimulation. Restimulation of CMV‐specific CD4+ effector‐memory T helper cells by autologous PDC and induction of IFN‐I production in PDC are dependent on appropriate stimulation. Type B CpG oligonucleotide (CpG‐B)‐stimulated PDC efficiently process and present CMV antigen and are thus capable of stimulating CMV‐specific effector‐memory T helper cells. CpG‐A‐stimulated PDC produce large amounts of IFN‐I and express programmed death receptor‐1 ligand 1. CpG‐A plus CpG‐B‐co‐stimulated PDC behave like CpG‐B‐stimulated PDC, suggesting that antigen processing and presentation in PDC is dependent on stimulation that concurrently inhibits IFN‐I production. In vivo targeting of antigens to PDC via CD303 combined with appropriate PDC stimulation may allow induction of specific T cell activation.Supporting Information for this article is available at http://www.wiley‐vch.de/contents/jc_2040/2008/37552_s.pdf
CCL2 recruitment of IL‐6‐producing CD11b+ monocytes to the draining lymph nodes during the initiation of Th17‐dependent B cell‐mediated autoimmunity
Authors: Bai Ying , Liu Ruolan , Huang DeRen , La Cava Antonio , Tang Yi‐yuan , Iwakura Yoichiro , Campagnolo Denise I. , Vollmer Timothy L. , Ransohoff Richard M. , Shi Fu‐Dong 
Published: June 2008

AbstractThe development and function of Th17 cells are influenced in part by the cytokines TGF‐β, IL‐23 and IL‐6, but the mechanisms that govern recruitment and activity of Th17 cells during initiation of autoimmunity remain poorly defined. We show here that the development of autoreactive Th17 cells in secondary lymphoid organs in experimental autoimmune myasthenia gravis – an animal model of human myasthenia gravis – is modulated by IL‐6‐producing CD11b+ cells via the CC chemokine ligand 2 (CCL2). Notably, acetylcholine receptor (AChR)‐reactive Th17 cells provide help for the B cells to produce anti‐AChR antibodies, which are responsible for the impairment of the neuromuscular transmission that contributes to the clinical manifestations of autoimmunity, as indicated by a lack of disease induction in IL‐17‐deficient mice. Thus, Th17 cells can promote humoral autoimmunity via a novel mechanism that involves CCL2.Supporting Information for this article is available at www.wiley‐vch.de/contents/jc_2040/2008/37973_s.pdf
Systemic increase in type I interferon activity in Sjögren's syndrome: A putative role for plasmacytoid dendritic cells
Authors: Wildenberg Manon E. , van Helden‐Meeuwsen Cornelia G. , van de Merwe Joop P. , Drexhage Hemmo A. , Versnel Marjan A. 
Published: June 2008

AbstractIn the salivary glands of primary Sjögren's syndrome (pSjS) patients, type I IFN activity is increased, but systemic levels of type I IFN proteins are rarely detected. This study focused on the systemic activity of type I IFN in pSjS, as well as the role of peripheral plasmacytoid dendritic cells (pDC). Monocytes obtained from pSjS patients showed an increased expression of 40 genes. Twenty‐three of these genes (58%), including IFI27, IFITM1, IFIT3 and IFI44, were inducible by type I IFN. pSjS serum had an enhanced capability of inducing IFI27, IFITM1, IFIT3 and IFI44 in the monocytic cell line THP‐1, likely due to the action of IFN‐β. This effect could be inhibited by blocking the type I IFN receptor, supporting a high type I IFN bioactivity in pSjS serum. In addition, circulatory pDC showed increased expression of CD40. This expression was correlated to the expression level of the type I IFN‐regulated genes IFI27 and IFITM1 in monocytes of the same individual. This study indicates that the increased type I IFN activity observed in pSjS patients is not only a local but also a systemic phenomenon and points to pDC as a possible source of this activity.
Intra‐tumoral Salmonella typhimurium induces a systemic anti‐tumor immune response that is directed by low‐dose radiation to treat distal disease
Authors: Avogadri Francesca , Mittal Deepak , Saccheri Fabiana , Sarrafiore Massimo , Ciocca Mario , Larghi Paola , Orecchia Roberto , Rescigno Maria 
Published: June 2008

AbstractSalmonella typhimurium is a facultative anaerobic bacterium able to multiply preferentially in tumors and inhibit their growth. The mechanisms through which Salmonella exerts its anti‐cancer properties are not fully understood. We recently showed that intra‐tumoral Salmonella injection results not only in the regression of even bulky tumor masses, but also impacts on the growth of distant untreated lesions. Here we describe how Salmonella exerts its systemic anti‐cancer effects and means to potentiate them. The outburst of an early inflammatory reaction in the treated tumor promotes the development of an immunostimulatory cytokine environment both locally and in the draining lymph node. Within the next 10 days, an efficient cross‐presentation of endogenous tumor antigens by dendritic cells at the tumor‐draining lymph node leads to the priming of effective anti‐tumor CD8+ T cell responses. This potentially broadly reactive T cell repertoire can be directed to other pre‐established melanomas by low‐dose radiotherapy enhancing the Salmonella anti‐cancer effect. We demonstrate that Salmonella‐based therapy coupled to low‐dose radiotherapy dampens tumor immune escape mechanisms at different levels and allows controlling systemic disease in a CD8+ T cell‐dependent manner.
Interferon‐γ limits the availability of iron for intramacrophage Salmonella typhimurium
Authors: Nairz Manfred , Fritsche Gernot , Brunner Peter , Talasz Heribert , Hantke Klaus , Weiss Günter 
Published: June 2008

AbstractIn stimulating effector functions of mononuclear phagocytes, IFN‐γ is of pivotal importance in host defense against intramacrophage pathogens including salmonellae. As the activity of IFN‐γ is modulated by iron and since a sufficient availability of iron is essential for the growth of pathogens, we investigated the regulatory effects of IFN‐γ on iron homeostasis and immune function in murine macrophages infected with Salmonella typhimurium. In Salmonella‐infected phagocytes, IFN‐γ caused a significant reduction of iron uptake via transferrin receptor 1 and resulted in an increased iron efflux caused by an enhanced expression of the iron exporter ferroportin 1. Moreover, the expression of haem oxygenase 1 and of the siderophore‐capturing antimicrobial peptide lipocalin 2 was markedly elevated following bacterial invasion, with IFN‐γ exerting a super‐inducing effect. This observed regulatory impact of IFN‐γ reduced the intracellular iron pools within infected phagocytes, thus restricting the acquisition of iron by engulfed Salmonella typhimurium while concomitantly promoting NO and TNF‐α production. Our data suggest that the modulation of crucial pathways of macrophage iron metabolism in response to IFN‐γ concordantly aims at withdrawing iron from intracellular Salmonella and at strengthening macrophage immune response functions. These regulations are thus consistent with the principles of nutritional immunity.See accompanying commentary http://dx.doi.org/10.1002/eji.200838505
Increased cytotoxicity of CD4+ invariant NKT cells against CD4+CD25hiCD127lo/– regulatory T cells in allergic asthma
Authors: Nguyen Khoa D. , Vanichsarn Chris , Nadeau Kari C. 
Published: June 2008

AbstractCD4+CD25hiCD127lo/– regulatory T cells (Treg) have been implicated in the resolution of asthma‐associated inflammation while the opposite role of CD4+ invariant NKT (iNKT) cells has been the subject of recent investigations. Studies here focused on mechanisms of interaction between CD4+ iNKT cells and Treg to further explore their roles in allergic asthma (AA). Flow cytometry analysis revealed a significant increase in the expression of the natural cytotoxicity receptors NKp30 and NKp46 by CD4+ iNKT cells in AA subjects compared to healthy controls (HC) and non‐allergic asthmatics (NA). Subsequent intracellular staining showed that CD4+ iNKT cells also expressed higher levels of granzyme B and perforin in AA than HC. In in vitro killing assays, AA CD4+ iNKT cells selectively killed autologous Treg, but not CD4+CD25– T cells, more potently than HC and NA counterparts. This increased cytotoxicity positively correlated with asthma severity and granzyme B/perforin expression of CD4+ iNKT cells. Furthermore, it could be abrogated by either inhibition of the granzyme B‐/perforin‐dependent cell death pathway or oral corticosteroid administration. Altogether, these findings suggest that increased cytotoxicity of CD4+ iNKT cells against Treg might contribute to dysfunctional cellular interactions in AA.Supporting Information for this article is available at www.wiley‐vch.de/contents/jc_2040/2008/38082_s.pdf
The canonical Wnt signaling pathway plays an important role in lymphopoiesis and hematopoiesis
Authors: Staal Frank J. T. , M. Sen Jyoti 
Published: June 2008

AbstractThe evolutionarily conserved canonical Wnt‐β‐catenin‐T cell factor (TCF)/lymphocyte enhancer binding factor (LEF) signaling pathway regulates key checkpoints in the development of various tissues. Therefore, it is not surprising that a large body of gain‐of‐function and loss‐of‐function studies implicate Wnt‐β‐catenin signaling in lymphopoiesis and hematopoiesis. In contrast, recent papers have reported that Mx‐Cre‐mediated conditional deletion of β‐catenin and/or its homolog γ‐catenin (plakoglobin) did not impair hematopoiesis or lymphopoiesis. However, these studies also report that TCF reporter activity remains active in β‐catenin‐ and γ‐catenin‐deficient hematopoietic stem cells and all cells derived from these precursors, indicating that the canonical Wnt signaling pathway was not abrogated. Therefore, these studies in fact show that the canonical Wnt signaling pathway is important in hematopoiesis and lymphopoiesis, even though the molecular basis for the induction of the reporter activity is currently unknown. In this perspective, we provide a broad background to the field with a discussion of the available data and create a framework within which the available and future studies may be evaluated.
Molecular mimicry in innate immunity? The viral RNA recognition receptor TLR7 accelerates murine lupus
Authors: Anders Hans‐Joachim , Krug Anne , Pawar Rahul D. 
Published: June 2008

AbstractToll‐like receptors (TLR), such as TLR7, were first described as innate pathogen recognition receptors that trigger appropriate antimircrobial immune responses upon exposure to pathogen‐associated molecules, e.g. viral ssRNA. In parallel to ongoing studies on TLR‐biology, mounting experimental evidence suggests that endogenous RNA‐related autoantigens may also activate dendritic cells (DC) and B cells through TLR7. TLR7‐mediated DC activation, autoantibody secretion, lymphoproliferation, and autoimmune tissue injury, are frequently observed in various murine models of systemic lupus and lupus nephritis. A paper in the current issue of the European Journal of Immunology, provide striking experimental evidence for this concept; the authors show that the Y chromosome‐linked autoimmune accelerating (Yaa) translocation from the X‐chromosome, consisting of 16 genes including Tlr7, largely mediates the autoimmune phenotype via the duplication of Tlr7. This finding highlights the need to address the significance of TLR7 in human lupus in terms of both genetic risk and as a therapeutic option.See accompanying article: http://dx.doi.org/10.1002/eji.200838138
A Fast Catalytic Asymmetric Aza‐Morita–Baylis–Hillman Reaction of N‐Sulfonated Imines with Methyl Vinyl Ketone in the Presence of Chiral Bifunctional Phosphane Lewis Bases
Authors: Lei Zhi‐Yu , Ma Guang‐Ning , Shi Min 
Published: June 2008

AbstractA series of novel bifunctional chiral phosphane Lewis bases having one phenyl group and an electron‐donating alkyl group on the phosphorus atom was designed and successfully synthesized. The use of these bifunctional chiral phosphane Lewis bases in catalytic asymmetric aza‐Morita–Baylis–Hillman reactions (aza‐MBH reactions) of N‐sulfonated imines with methyl vinyl ketone affords the corresponding adducts in good‐to‐excellent yields and moderate‐to‐good enantioselectivities within a few hours at room temperature. To the best of our knowledge, this is the fastest catalytic asymmetric MBH reaction reported thus far.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
A Novel Potentiometric Sensor for Thiocyanate Based on an Amide‐Linked Manganese Diporphyrin Xanthene
Authors: Dong Yan‐Yan , Li Chun‐Yan , Zhang Xiao‐Bing , Yu Ru‐Qin , Shen Guo‐Li 
Published: June 2008

AbstractThe synthesis of a new compound, amide‐linked manganese diporphyrin xanthene (Mn2Cl2ADPX), and its application for preparation of thiocyanate selective electrodes was described. The electrode was prepared with a PVC membrane combining Mn2Cl2ADPX as an electro active material, 2‐nitrophenyl octyl ether (o‐NPOE) as a plasticizer in the percentage ratio of 3 : 65 : 32 (Mn2Cl2ADPX: o‐NPOE: PVC, w : w : w). The electrode exhibited linear response within the concentration range of 2.4×10−6 to 1.0×10−1 M SCN−, with a working pH range from 3.0 to 8.0 and a fast response time of less than 60 s. Several electroactive materials and solvent mediators have been compared and the experimental conditions were optimized. The Mn2Cl2ADPX based electrode shows obviously better response characteristics than that of monoporphyrin manganese in terms of working concentration range and slope. Selectivity coefficients for SCN− relative to a number of interfering ions were investigated. The electrode exhibits anti‐Hofmeister selectivity toward SCN− with respect to common coexisting anions. The electrode was applied to the determination of SCN− in body urine with satisfactory results.
Synthesis and Characterization of MWNTs/Au NPs/HS(CH2)6Fc Nanocomposite: Application to Electrochemical Determination of Ascorbic Acid
Authors: Qiu Jian‐Ding , Wang Rui , Liang Ru‐Ping , Xiong Meng 
Published: June 2008

AbstractIn this article, a detailed electrochemical study of a novel 6‐ferrocenylhexanethiol (HS(CH2)6Fc) self‐assembled multiwalled carbon nanotubes‐Au nanoparticles (MWNTs/Au NPs) composite film was demonstrated. MWNTs/Au NPs were prepared by one‐step in situ synthesis using linear polyethyleneimine (PEI) as bifunctionalizing agent. HS(CH2)6Fc, which acted as the redox mediator, was self‐assembled to MWNTs/Au NPs via Au‐S bond. Transmission electron microscopy (TEM), energy‐dispersive X‐ray analysis (EDX), Fourier transformed infrared absorption spectroscopy (FT‐IR), UV‐visible absorption spectroscopy, and cyclic voltammetry were used to characterize the properties of the MWNTs/Au NPs/HS(CH2)6Fc nanocomposite. The preparation of the nanocomposite was very simple and effectively prevented the leakage of the HS(CH2)6Fc mediator during measurements. The electrooxidation of AA could be catalyzed by Fc/Fc+ couple as a mediator and had a higher electrochemical response due to the unique performance of MWNTs/Au NPs. The nanocomposite modified electrode exhibited excellent catalytic efficiency, high sensitivity, good stability, fast response (within 3 s) and low detection limit toward the oxidation of AA at a lower potential.
Comparison of the Electrochemical Reactivity of Carbon Nanotubes Paste Electrodes with Different Types of Multiwalled Carbon Nanotubes
Authors: Li Xueling , Ye Jianshan 
Published: June 2008

AbstractCarbon nanotubes (CNTs) are widely used in electrochemical studies. It is reported that CNTs with different source and dispersed in different agents [1] yield significant difference of electrochemical reactivity. Here we report on the electrochemical performance of CNTs paste electrodes (CNTPEs) prepared by multiwalled carbon nanotubes (MWNTs) with different diameters, lengths and functional groups. The resulting electrodes exhibit remarkable different electrochemical reactivity towards redox molecules such as NADH and K3[Fe(CN)6]. It is found that CNTPEs prepared by MWNTs with 20–30 nm diameter show highest catalysis to NADH oxidation, while CNTPEs prepared by MWNTs with carboxylate groups have best electron‐transfer rate (The peak‐peak separation (ΔEp) is +0.108 V for MWNTs with carboxylate groups, +0.155 V for normal MWNTs, and +0.174 V for short MWNTs) but weak catalysis towards oxidation of NADH owing to the hydrophilicity of carboxylate groups. The electrochemical reactivity depends on the lengths of CNTs to some extent. The ‘long’ CNTs perform better in our study (The oxidation signals of NADH appear below +0.39 V for ‘long’ CNTs and above +0.46 V for the ‘short’ one totally). Readers may get some directions from this article while choose CNTs for electrochemical study.
DNA Stabilization and Hybridization Detection on Porous Silicon Surface by EIS and Total Reflection FT‐IR Spectroscopy
Authors: Vamvakaki Vicky , Chaniotakis Nikos A. 
Published: June 2008

AbstractElectrochemically etched porous silicon (PSi) is formed and employed as a substrate for the entrapment of oligonucleotides and the subsequent development of stable DNA biosensors. The controlled potential anodic etching of p‐type silicon wafers is optimized in order to obtain a surface layer with pore diameters which are close to those of the adsorbed DNA helix. The stabilization and hybridization of DNA inside the PSi layer is confirmed using ATR‐FTIR. Moreover hybridization is verified by the large and reproducible impedance changes at the interface layer. The developed PSi DNA sensor paves the way for the label‐free detection of oligonucleotide sequences in DNA microarrays and microfabricated PSi field‐effect sensors.
Principles of whole‐body continuously‐moving‐table MRI
Authors: Börnert Peter , Aldefeld Bernd 
Published: June 2008

AbstractContinuously‐moving‐table (CMT) imaging is a new and promising approach to virtually extend the field‐of‐view (FOV) in currently available MRI systems. It shows high potential to improve a number of applications that require a large FOV, such as whole‐body contrast‐enhanced angiography and contrast‐optimized whole‐body head‐to‐toe imaging. In this work, an overview of the different approaches to CMT imaging is given. Basic principles of two‐ and three‐dimensional (2D and 3D) techniques are discussed, with emphasis on performance and image‐artifact issues. Potential clinical applications and further desirable improvements are outlined. J. Magn. Reson. Imaging 2008;28:1–12. © 2008 Wiley‐Liss, Inc.