bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of food processing of pearl millet (Pennisetum glaucum) IKMP‐5 on the level of phenolics, phytate, iron and zinc
Authors: Eyzaguirre Romina Zanabria , Nienaltowska Katarzyna , de Jong Linda EQ , Hasenack Birgit BE , Nout MJ Robert
Published: May 2006

Pearl millet is consumed as a staple food in semi‐arid tropical regions. With a view to upgrading the micronutrient status of pearl millet‐based foods, the effects of single operations and of porridge preparation scenarios on levels and in vitro solubility (IVS) of iron and zinc and mineral complexing factors (phytates: inositol phosphates and phenolic compounds) were tested. Disc milling of grain may add significant iron but this is not necessarily IVS iron. Soaking of grains results in a 25% loss of iron, but also facilitates endogenous phytate degradation, particularly when combined with milling and cooking. Germination and lactic acid fermentation both result in partial phytate degradation. Cooking does not decompose phytates, but results in complex formation of phenolic compounds as measured by a significant reduction in reactive hydroxyl groups. Because of its different distribution in the grain, zinc is generally less affected than iron. Phytate reduction by endogenous phytases is inhibited at low pH as caused by fermentation. Kanwa (alkaline rock salt) could be a functional cooking ingredient as a source of minerals and to react with phenolic substances. The relative IVS of iron was doubled by germination of grain and increased 3‐fold by fermentation of wholemeal slurry. Zinc IVS tended to increase on cooking with kanwa, but decreased in cooked fermented flour. Copyright © 2006 Society of Chemical Industry
Visible transmission spectroscopy for the assessment of egg freshness
Authors: Kemps Bart J , Bamelis Flip R , De Ketelaere Bart , Mertens Kristof , Tona Kokou , Decuypere Eddy M , De Baerdemaeker Josse G
Published: May 2006

The objective of this research was to investigate the feasibility of visible transmission spectroscopy for the non‐destructive assessment of the freshness of an individual egg. A total of 600 intact white‐shelled eggs of the same flock (Lohmann, 40 weeks of age) were measured. To obtain a considerable variation in freshness, groups consisting of 60 eggs were stored (18 °C, 55% RH) for 0, 2, 4, 6, 8, 10, 12, 14, 16 and 18 days. The non‐destructive spectral measurements were compared with the two most widely used destructive freshness parameters, namely Haugh units and albumen pH. A partial least squares (PLS1) model was built in order to predict Haugh units and pH of the albumen based on the transmission spectra. The correlation coefficients between the predicted value and the measured value were 0.842 and 0.867 for Haugh unit and pH of the albumen, respectively. These results show that the light transmission spectrum of an egg provides quantitative information about egg freshness. Relevant information concerning egg freshness is restricted to the interval between 570 and 750 nm. Furthermore, the models obtained for both destructive parameters were strikingly similar, indicating that Haugh unit and pH have the same physico‐chemical background. Copyright © 2006 Society of Chemical Industry
A handbook‐based methodology for redesigning business processes
Authors: Klein Mark , Petti Claudio
Published: May 2006

This paper presents a structured methodology, based on the use of a Handbook of process models, for redesigning business processes. The methodology is illustrated using examples from the agri‐food supply chain domain. We discuss the strengths and weaknesses of this approach, and identify avenues for further work. Copyright © 2006 John Wiley & Sons, Ltd.
Metrics collection for process knowledge—a practitioners' guide
Authors: Dawson Ray , Nolan Andrew J.
Published: May 2006

This paper describes a number of experiences of gathering metrics to supply the knowledge needed for decision making and process management in an industrial environment. The experiences are summarised as guidelines in the form of a list of ‘Do’s and ‘Do not’s for collecting and using metrics for this purpose. While the paper is clearly anecdotal in nature, these guidelines should, nevertheless, allow other managers to draw on the experience of the authors to put a successful metrics programme in place to provide knowledge for decision making and process improvement.

The paper concludes, however, that there are limitations that exist for metrics programmes implemented, even if the guidelines are followed. The metrics cannot always offer evidence that any particular action or technique has given a better project management methodology. However, when used with other investigations they can give a better knowledge and understanding of processes that should enable more effective management. Copyright © 2006 John Wiley & Sons, Ltd.
Locating knowledge sources through keyphrase extraction
Authors: Tedmori Sara , Jackson Thomas W. , Bouchlaghem Dino
Published: May 2006

There are a large number of tasks for which keyphrases can be useful. Manually identifying keyphrases can be a tedious and time consuming process that requires expertise, but if automated could save time and aid in creating metadata that could be used to locate knowledge sources. In this paper, the authors present an automated process for keyphrase extraction from e‐mail messages. The process enables users to find other people who might hold the knowledge they require from information communicated via the e‐mail system. The effectiveness of the extraction system is tested and compared against other extraction systems and the overall value of extracting information from e‐mail explored. Copyright © 2006 John Wiley & Sons, Ltd.
Objectivity and subjectivity in knowledge management: a review of 20 top articles
Authors: Nonaka Ikujiro , Peltokorpi Vesa
Published: May 2006

In recent years knowledge management (KM) has received increased attention from academics and practitioners. There are several challenges to establishing KM as a separate discipline one of the most central being conceptual plurality. The purpose of this paper is to review and position 20 of the most frequently cited KM articles in management journals. More specifically, this paper classifies the KM publications on the subjectivity–objectivity continuum, discusses the strengths and weaknesses of the publications drawing from positivism and interpretative philosophies, and further discusses the challenges in KM, and how objectivity and subjectivity can be used to provide both product and process orientations in future research. Copyright © 2006 John Wiley & Sons, Ltd.
Quantitative survival model for short-term survival after adult-to-adult living donor liver transplantation
Authors: Tsunematsu Ichiro , Ogura Yasuhiro , Inoue Kayoko , Koizumi Akio , Tanigawa Nobuhiko , Tanaka Koichi
Published: May 2006

Adult-to-adult living donor liver transplantation (ALDLT) has been accepted as an important option for end-stage liver disease, but information regarding the risk factors remains fragmentary. We aimed to establish a predictive model for 90-day survival. In the first step, a total of 286 cases who had received primary ALDLT using a right lobe graft between 1998 and 2004 were randomly divided into 2 cohorts at a ratio of 2:1 (191 vs. 95 recipients). The larger cohort of patients was used to develop a model. The outcome was defined as 90-day survival, and a total of 39 preoperative and operative variables, including the period of surgery (1998–2001 vs. 2002–2004), were included using Cox's proportional hazard regression model. Two mismatches of human leukocyte antigen (HLA) type DR (hazard ratio [HR] = 4.45; confidence interval [CI] = 1.96–10.1), loge[blood loss volume] (HR = 2.43; CI = 1.64–3.60), period of surgery (1998–2001 vs. 2002–2004) (HR = 2.41; CI = 1.04–5.57), and loge[serum C-reactive protein or CRP] (HR = 1.64; CI = 1.13–2.38) were found to be independent risk factors. In the second step, we tried to establish a realistic survival model. In this step, we created 2 models, 1 that used all 4 variables (model 1) and 1 (model 2) in which blood loss volume was replaced with the past history of upper abdominal surgery and Model for End-Stage Liver Disease (MELD) score (≥25), both of which showed associations with blood loss volume. These models were applied to the smaller cohort of 95 patients. Receiver operating characteristic analyses demonstrated that both models showed similar significant c-statistics (0.63 and 0.62, respectively). In conclusion, model 2 can provide a rough estimation of the 90-day survival after ALDLT.
Liver Transpl 12:904–911, 2006.

© 2006 AASLD.
Impact of preoperative steroids administration on ischemia-reperfusion injury and systemic responses in liver surgery: A prospective randomized study
Authors: Aldrighetti Luca , Pulitanò Carlo , Arru Marcella , Finazzi Renato , Catena Marco , Soldini Laura , Comotti Laura , Ferla Gianfranco
Published: May 2006

Hepatic injury secondary to warm ischemia-reperfusion (I/R) injury and alterations in haemostatic parameters are often unavoidable events after major hepatic resection. The release of inflammatory mediator is believed to play a significant role in the genesis of these events. It has been suggested that preoperative steroid administration may reduce I/R injury and improve several aspects of the surgical stress response. The aim of this prospective randomized study was to investigate the clinical benefits on I/R injury and systemic responses of preoperatively administered corticosteroids. Seventy-six patients undergoing liver resection were randomized either to a steroid group or to a control group. Patients in the steroid group received preoperatively 500 mg of methylprednisolone. Serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), total bilirubin, coagulation parameters, and inflammatory mediators, interleukin 6 and tumor necrosis factor alpha were compared between the 2 groups. Length of stay, and type and number of complications were recorded as well. Postoperative serum levels of ALT, AST, total bilirubin, and inflammatory cytokines were significantly lower in the steroid than in the control group at postoperative days 1 and 2. Changes in hemostatic parameters were also significantly attenuated in the steroid group. In conclusion, the incidence of postoperative complications in the steroid group tended to be significantly lower than the control group. It is of clinical interest that preoperative steroids administration before major surgery may reduce I/R injury, maintain coagulant/anticoagulant homeostasis, and reduce postoperative complications by modulating the inflammatory response.
Liver Transpl 12:941–949, 2006.

© 2006 AASLD.
Synthesis of CdS Nanoparticles Dispersed Within Poly(urethane acrylate‐co‐styrene) Films Using an Amphiphilic Urethane Acrylate Nonionomer
Authors: Kim Ju‐Young , Kim Hyun‐Mi , Shin Dong‐Hyun , Ihn Kyo‐Jin
Published: May 2006

Summary: CdS nanoparticles dispersed within poly(urethane acrylate‐co‐styrene) (PUCS) films were prepared using amphiphilic urethane acrylate nonionomer (UAN) precursor chains, which had a poly(propylene oxide)‐based hydrophobic segment and a hydrophilic poly(ethylene oxide) segment. CdS nanoparticles were first prepared and dispersed in UAN/styrene mixtures, and then these nano‐colloid solutions could be directly converted to CdS/PUCS nanocomposite films via radical bulk polymerization process. Formation of CdS nanoparticles was confirmed by UV absorption spectra, PL emission spectra and TEM images. The size of the CdS nanoparticles was varied from 10.2 to 14.5 nm, in correlation with the increase of amount of cadmium salt in the preparation composition, which was also confirmed by a red shift in the UV and PL emission spectra. In the course of the formation of the CdS nanoparticles within the UAN/styrene mixtures, the PEO segments of UAN are microphase‐separated from the hydrophobic segments of UAN and styrene to make a complex with the cadmium cations and stabilize the CdS nanoparticles. This was also confirmed by TEM images and DMA measurements.

TEM micrograph of the polyurethane acrylate films containing CdS nanoparticles, prepared using a weight fraction of cadmium acetate of 0.125 wt.‐%.

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TEM micrograph of the polyurethane acrylate films containing CdS nanoparticles, prepared using a weight fraction of cadmium acetate of 0.125 wt.‐%.
Electrostatic‐Assembly of Carbon Nanotubes (CNTs) and Polymer Particles in Water: a Facile Approach to Improve the Dispersion of CNTs in Thermoplastics
Authors: Peng Mao , Li Dasong , Chen Ying , Zheng Qiang
Published: May 2006

Summary: A facile and organic‐solvent‐free method for preparing thermoprocessable multiwalled carbon nanotube (MWCNT)‐filled thermoplastics is presented. MWCNTs are oxidized, neutralized, and then assembled with cationic soap‐free poly(methyl methacrylate) (PMMA) particles directly in water. The spontaneous electrostatic coupling between the negatively charged MWCNTs and positively charged PMMA particles, and the viscoelastic and thermomechanical behavior of the nanocomposites, are investigated. The electrostatic coupling interactions improve the dispersion of nanotubes and facilitate the formation of filler networks in the polymer matrix.

Preparation of nanocomposites of oxidized MWCNTs and positively charged PMMA particles through electrostatic assembly.

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Preparation of nanocomposites of oxidized MWCNTs and positively charged PMMA particles through electrostatic assembly.
Grafting of Poly(tBA) and PtBA‐b‐PMMA onto the Surface of SWNTs Using Carbanions as the Initiator
Authors: Chen Shimou , Chen Daoyong , Wu Guozhong
Published: May 2006

Summary: Soluble carbon nanotubes were prepared by treating SWNTs with sec‐butyllithium and subsequently using the generated carbanions as the initiator to graft PtBA and PtBA‐b‐PMMA onto the surface of SWNTs. The anionic polymerization initiated by SWNTs‐bearing carbanions not only provides a powerful strategy for functionalizing SWNTs but also gives us knowledge of the sidewall chemistry of SWNTs. The results indicate that a carbanion born on SWNTs behaves like an anionic initiator with high steric hindrance.

Anionic polymerization of (meth)acrylate monomer.

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Anionic polymerization of (meth)acrylate monomer.
Living Free Radical Polymerization of Cyclodextrin Host‐Guest Complexes of Styrene via the Reversible Addition Fragmentation Chain Transfer (RAFT) Process in Aqueous Solution
Authors: Köllisch Heike , Barner‐Kowollik Christopher , Ritter Helmut
Published: May 2006

Summary: Host‐guest complexes of styrene and randomly methylated β‐cyclodextrin (m‐β‐CD) were polymerized in aqueous medium via the reversible addition fragmentation chain transfer (RAFT) process. 3‐Benzylsulfanylthiocarbonylsulfanylpropionic acid (TTC) was used as trithiocarbonate‐type RAFT agent. The results indicate a controlled character of the polymerization of the styrene complexes as the number‐average molecular weight, $\overline M _{\rm n}$, increases linearly with monomer to polymer conversion; however, the molecular weights of the obtained polystyrenes deviate to higher values than those theoretically predicted. Nevertheless, the molecular weights can be controlled by variation of the initial RAFT agent concentration. The polystyrenes produced in this system exhibited narrower polydispersities (1.23 < $\overline M _{\rm w} /\overline M _{\rm n}$ < 2.36) than those produced without RAFT agent (5.24 < $\overline M _{\rm w} /\overline M _{\rm n}$ < 9.21) under similar conditions. The present contribution represents the first example of RAFT polymerization of a m‐β‐CD‐complexed hydrophobic vinylmonomer (styrene) from homogenous aqueous solution.

Schematic presentation of complexation and RAFT polymerization of m‐β‐CD‐complexed styrene with TTC as RAFT agent and evolution of the full molecular weight distributions in the CD‐mediated styrene free radical RAFT polymerization.

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Schematic presentation of complexation and RAFT polymerization of m‐β‐CD‐complexed styrene with TTC as RAFT agent and evolution of the full molecular weight distributions in the CD‐mediated styrene free radical RAFT polymerization.
Supramolecular Self‐Assembly of Polymer‐Functionalized Carbon Nanotubes on Surfaces
Authors: Gao Chao
Published: May 2006

Summary: Supramolecular self‐assembly of poly(methyl methacrylate)‐grafted multiwalled carbon nanotubes (MWNT‐g‐PMMA) was reported herein. The MWNT‐g‐PMMA (85 wt.‐% PMMA) dispersed in tetrahydrofuran could self‐assemble into suprastructures on surfaces such as gold, mica, silicon, quartz, or carbon films. With decreasing concentration of the MWNT‐g‐PMMA from 3 to 0.1 mg · mL−1, the assembled structures changed from cellular and basketwork‐like forms to multilayer cellular networks and individual needles. SEM, AFM, and TEM measurements confirmed the morphology of the assembled suprastructures, and revealed the assembly mechanism. Phase separation during evaporation of the solvent drives the MWNT‐g‐PMMA nanohybrids to assemble and form the suprastructures, and the rigid MWNTs stabilize the structures.

SEM images of self‐assembled suprastructures of basketwork (a), cellular network (b), and needles (c) from the THF solution of the PMMA‐grafted MWNTs on gold surface.

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SEM images of self‐assembled suprastructures of basketwork (a), cellular network (b), and needles (c) from the THF solution of the PMMA‐grafted MWNTs on gold surface.
Effect of Chain Straightening on Plateau Modulus and Entanglement Molecular Weight of Ni‐diimine Poly(1‐hexene)s
Authors: Ye Zhibin , Feng Wei , Zhu Shiping , Yu Qiang
Published: May 2006

Summary: In this communication, we report the first rheological study on the chain‐straightened Ni‐diimine poly(1‐hexene)s and investigate the unique effect of chain straightening on plateau modulus and entanglement molecular weight of this series of polymers. Two Ni‐diimine poly(1‐hexene) samples having different levels of chain straightening were prepared with a chain‐walking Ni‐diimine catalyst, (ArNC(An)C(An)NAr)NiBr2 (An = acenaphthene, Ar = 2,6‐(i‐Pr)2C6H3) at two different temperatures. Rheological analyses show that the chain‐straightened polymers exhibit significantly enhanced plateau modulus and reduced entanglement molecular weight compared to regular poly(1‐hexene)s by metallocene catalysis. Such an effect becomes more pronounced with an increase in the level of chain straightening.

Loss moduli G″(ω) versus reduced angular frequency in a linear, natural logarithm plot for the three polymers at the reference temperature of 100 °C.

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Loss moduli G″(ω) versus reduced angular frequency in a linear, natural logarithm plot for the three polymers at the reference temperature of 100 °C.
A Main‐Chain Liquid‐Crystalline Oligomer Prepared by in situ Photopolymerization of an LC Monomer Having Cinnamate Moieties
Authors: Kihara Hideyuki , Tamaoki Nobuyuki
Published: May 2006

Summary: A liquid‐crystalline (LC) compound, having a cinnamate moiety on each end of the molecule, was synthesized and irradiated with UV light in its LC phase in the presence of a triplet sensitizer. Various measurements of the irradiated sample revealed that the linearly structured LC oligomers were formed by [2+2] cycloaddition of the cinnamate moieties, and that the resultant cyclobutane units dominantly assumed an anti head‐to‐head configuration.

Schematic structures of the LC oligomer obtained by photopolymerization.

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Schematic structures of the LC oligomer obtained by photopolymerization.
Substitution and protonation effects on spin–spin coupling constants in prototypical aromatic rings: C6H6, C5H5N and C5H5P
Authors: Del Bene Janet E. , Elguero José
Published: May 2006

Ab initio equation‐of‐motion coupled cluster calculations have been carried out to evaluate one‐, two‐, and three‐bond 13C13C, 15N13C, 31P13C coupling constants in benzene, pyridine, pyridinium, phosphinine, and phosphininium. The introduction of N or P heteroatoms into the aromatic ring not only changes the magnitudes of the corresponding XC coupling constants (J, for X = C, N, or P) but also the signs and magnitudes of corresponding reduced coupling constants (K). Protonation of the heteroatoms also produces dramatic changes in coupling constants and, by removing the lone pair of electrons from the σ‐electron framework, leads to the same signs for corresponding reduced coupling constants for benzene, pyridinium, and phosphininium. CC coupling constants are rather insensitive to the presence of the heteroatoms and protonation. All terms that contribute to the total coupling constant (except for the diamagnetic spin‐orbit (DSO) term) must be computed if good agreement with experimental data is to be obtained. Copyright © 2006 John Wiley & Sons, Ltd.
Effects of cold storage on the function and morphology of isolated urinary bladder in rat
Authors: Liu Guiming , Daneshgari Firouz
Published: May 2006

Aims

We investigated the effects of 24‐ and 48‐hr storage at 4°C in Krebs solution on the function and morphology of isolated, rat urinary bladders.

Methods

Strips of bladder were obtained from eight male Sprague–Dawley rats. Six strips were harvested from each bladder and randomized to storage for 24 or 48 hr at 4°C in Krebs solution or examination immediately after harvest. Contractile responses of the strips to potassium chloride (KCl), electric field stimulation (EFS), adenosine 5′‐triphosphate (ATP) and carbamylcholine (CCh) were assessed. Histological examination of the bladder strips was performed. The pO2, pCO2, and pH of the solution in each storage container were measured at each storage time point.

Results

Cold storage induced a significant decrease in the amplitude of contraction in response to KCl and EFS after 24 or 48 hr of storage compared with control. The response of the bladder strips to ATP and CCh was significantly reduced after 48‐hr storage compared with control, but not 24‐hr storage. The pO2 and pCO2 decreased after cold storage. The pH increased after 24 hr of storage and remained stable between 24 and 48 hr of storage. Histological evaluation of the strips showed tissue swelling after 24 and 48 hr of storage.

Conclusions

These results suggest that the morphology and function of bladder strips stored for 24 to 48 hr at 4°C in Krebs solution undergo significant changes. Further studies are needed to assess the allowable time for storage of bladder tissue. Neurourol. Urodynam. © 2006 Wiley‐Liss, Inc.
Reliability inference for field conditions from accelerated degradation testing
Authors: Liao Haitao , Elsayed Elsayed A.
Published: May 2006

Accelerated degradation testing (ADT) is usually conducted under deterministic stresses such as constant‐stress, step‐stress, and cyclic‐stress. Based on ADT data, an ADT model is developed to predict reliability under normal (field) operating conditions. In engineering applications, the “standard” approach for reliability prediction assumes that the normal operating conditions are deterministic or simply uses the mean values of the stresses while ignoring their variability. Such an approach may lead to significant prediction errors. In this paper, we extend an ADT model obtained from constant‐stress ADT experiments to predict field reliability by considering the stress variations. A case study is provided to demonstrate the proposed statistical inference procedure. The accuracy of the procedure is verified by simulation using various distributions of field stresses. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006.
The antibody 2B4 directed against the Epstein–Barr virus (EBV)‐encoded nuclear antigen 1 (EBNA1) detects MAGE‐4: implications for studies on the EBV association of human cancers
Authors: Hennard C , Pfuhl T , Buettner M , Becker K‐F , Knöfel T , Middeldorp J , Kremmer E , Niedobitek G , Grässer FA
Published: May 2006

We have previously developed two monoclonal antibodies against the Epstein–Barr Virus (EBV) nuclear antigen 1 (EBNA1), designated 1H4 and 2B4. Both detect EBNA1 by in situ staining in established EBV‐positive tumours, e.g. Hodgkin's lymphoma and nasopharyngeal carcinoma. An association of EBV with other tumours, notably breast carcinomas, has been reported but remains controversial. Using the antibody 2B4, a nuclear protein has been detected in breast carcinomas that were EBV‐negative by other methods, suggesting cross‐reactivity with a cellular protein. Furthermore, an association of EBV with various other carcinomas has been reported on the basis of 2B4 immunohistochemistry. Here we show that 2B4 also binds to MAGE‐4, a cancer testis antigen expressed in a variety of tumour cells, including breast carcinoma, seminoma and EBV‐negative cases of Hodgkin's lymphoma. We conclude that the 2B4 antibody is not suitable for the detection of EBV infection but that additional techniques, particularly in situ hybridization for the detection of the EBV‐encoded RNAs (EBERs), should be employed to confirm the presence of EBV. Our results add to the evidence indicating that breast cancer is not an EBV‐associated disease. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
MMTV‐like sequences in human breast cancer: a fluorescent PCR/laser microdissection approach
Authors: Zammarchi F , Pistello M , Piersigilli A , Murr R , Cristofano C Di , Naccarato AG , Bevilacqua G
Published: May 2006

The hypothesis that a retrovirus homologous to the mouse mammary tumour virus (MMTV) is involved in human breast cancer aetiology has fascinated scientists from many years, but it has never been convincingly demonstrated. Renewed interest in this hypothesis developed when an MMTV env gene‐like sequence was found in 38% of human breast cancer tissues. Whereas some subsequent studies confirmed these findings, others did not. The main reasons for this discrepancy, among others, are the different sensitivities and technical details of current molecular approaches to the detection of these sequences. This study is an attempt to find sensitive and reproducible conditions capable of detecting MMTV env‐like sequence in human samples. To this end, we first developed a fluorescence nested‐PCR (FN‐PCR) method that was able to detect very low copies of the viral genome, and then screened a panel of 45 frozen breast cancer samples obtained by laser microdissection. The MMTV env gene‐like sequence was found in 15 (33%) of the human breast cancers analysed, whereas the same sequence was detectable neither in normal tissues nor in other types of tumour. Sequence analysis revealed 96% homology with the MMTV genome, but no other significant similarities with the human genome. The combined use of frozen material, microdissected cell populations and FN‐PCR provides a novel, sensitive, robust, non‐radioactive and fast methodology for the molecular detection of human‐MTV. This approach might be successfully used in large molecular studies that aim to investigate the hypothesis of a retroviral aetiology of human breast cancer. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Prednisolone promotes remission and gastric mucosal regeneration in experimental autoimmune gastritis
Authors: Biondo M , Field J , Toh B‐H , Alderuccio F
Published: May 2006

A cardinal feature of organ‐specific autoimmunity is destructive pathology in the target organ. In human and experimental models of autoimmune gastritis, mononuclear cell infiltration and cellular destruction in the gastric mucosa are disease hallmarks. Strategies to cure autoimmune disease must not only establish immunological tolerance to autoantigen, but also rid the organ of pathogenic autoreactive cells. The present study has assessed the effect of prednisolone treatment in clearing the inflammatory infiltrate in experimental autoimmune gastritis and in preventing disease relapse in athymic compared with euthymic mice. Experimental autoimmune gastritis was induced by neonatal thymectomy or by transgenic expression of GM‐CSF (PC‐GMCSF mice). Groups of mice were treated with prednisolone (10 mg/kg per day) for 10 weeks or with prednisolone for 10 weeks followed by 10 weeks without prednisolone. Stomachs were examined for gross morphological changes, and by histology and immunohistochemistry for composition of inflammatory infiltrate and gastric mucosal integrity. Autoantibody to gastric H+/K+ ATPase was determined by ELISA. Prednisolone promoted remission of gastritis in both mouse models of experimental autoimmune gastritis, evident by reduction in stomach size, clearing of gastric inflammatory infiltrate, and regeneration of the gastric mucosa. Prednisolone withdrawal resulted in disease relapse in all PC‐GMCSF mice, whereas approximately 40% of neonatal thymectomy mice retained normal stomach morphology and remained free of gastric pathology. It is concluded that prednisolone promotes remission and gastric mucosal regeneration in experimental autoimmune gastritis. Prolonged remission of autoimmune gastritis in some athymic mice suggests a role for the thymus in disease relapse. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Development of a protocol for the semi‐synthesis and purification of betaxanthins
Authors: Gandía‐Herrero Fernando , García‐Carmona Francisco , Escribano Josefa
Published: May 2006

A method for the analytical and semi‐preparative chromatographic purification of betaxanthins is described together with an improved procedure for the semi‐synthesis of these compounds from betalamic acid. Standard conditions for obtaining preparative amounts of betaxanthins free of the precursor amino acids are provided. Following this procedure, 14 pure betaxanthins were obtained with yields of up to 100%. A simple reversed‐phase HPLC protocol for pigment identification and quantification is also provided. Calibration for betaxanthins is reported for the first time using the synthesised and purified pigments as standards. Structures were confirmed by UV–vis spectroscopy, HPLC retention times and electrospray ionization mass spectrometry. Betaxanthins can be obtained pure, and in sufficient amounts for further studies, which opens up new perspectives in the research and applications of these pigments. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of catalase‐like activity in plants based on the amperometric monitoring of hydrogen peroxide consumption using a carbon paste electrode modied with ruthenium(IV) oxide
Authors: Dousikou Melpomeni F. , Koupparis Michael A. , Efstathiou Constantinos E.
Published: May 2006

A carbon paste electrode containing ruthenium(IV) oxide as a modier was tested as an effective hydrogen peroxide amperometric sensor in bulk measurements (hydrodynamic amperometry). Factors that influence its overall analytical performance, such as pH and the applied potential, were examined. The RuO2‐modied electrode displayed high sensitivity towards hydrogen peroxide, with detection limits as low as 0.02 mm at pH 7.4 and 0.007 mm at pH 9.0. The method was applied for monitoring the decomposition of hydrogen peroxide (by catalase) in phosphate buffer of pH 7.4. The relative response of the electrode towards ascorbic acid was assessed and it was found that the selectivity of the RuO2‐modied electrode towards hydrogen peroxide over ascorbic acid could be signicantly improved by electro‐polymerizing m‐phenylenediamine on its surface prior to measurements. The RuO2‐modied electrode was used for the kinetic (xed time) determination of catalase activity in the range of 4–40 U/mL (detection limit 1.2 U/mL). The method was applied to the determination of catalase‐like activity in various plant materials (recovery ranged from 93 to 101%, detection limit 480 U/100 g). Copyright © 2006 John Wiley & Sons, Ltd.
RP‐HPLC detection of a sulphiting‐induced artefact from paeoniflorin in dried roots of Paeonia lactiflora
Authors: Hayes Patricia Y. , Lehmann Reg , Penman Kerry , Bone Kerry M. , Kitching William , De Voss James J.
Published: May 2006

Paeoniflorin is one of the bioactive ingredients of the roots of Paeonia lactiflora (Paeoniaceae). A comparative study of processed and non‐processed commercial samples of dried roots of P. lactiflora indicated a very low level of paeoniflorin in the processed sample and the formation of a new more polar component, sodium paeoniflorin sulphonate, during treatment of the roots with sulphiting agents. Copyright © 2006 John Wiley & Sons, Ltd.
A supramolecular network of 2‐(4,4,5,5‐tetramethyl‐3‐oxylimidazoline‐1‐oxide)‐5‐bromopyridine built through π–π stacking and hydrogen bonding interactions
Authors: Rajadurai Chandrasekar , Fuhr Olaf , Enkelmann Volker , Baumgarten Martin
Published: May 2006

The X‐ray study of 2‐(4,4,5,5‐tetramethyl‐3‐oxylimidazoline‐1‐oxide)‐5‐bromopyridine (PyNN) shows an unusual 3‐D supramolecular assembly formed by the combined non‐covalent interactions of π–π stacking and H‐bonding forces. The mean π–π stacking distance between two pyridine units is ∼3.64 Å. The angle between the plane of the pyridine ring and the stack column axis (c‐axis) is 7.46°. The H‐bonding distance between the oxygen atom of the water and the nitronyl nitroxide (NN) oxygen [H···ON] is 1.891 Å. Two potential short NO···ON contacts are found (NO1···O1N = 3.673 Å and NO1···O2N = 3.695 Å) along the stacked column. Four water molecules through H‐bonding with four different radical oxygens form a perfect square in the a, b plane which extends as a tubular cage along the stack axis. Experimental spin densities of PyNN estimated from the 1H‐NMR spectroscopy and its bulk magnetic property have been correlated with the X‐ray structure in an attempt to understand the possible magnetic exchange interactions. The observed low temperature antiferromagnetic interaction is analyzed on the basis of McConnell's model I (spin polarization approach) and this magnetic behavior is probably due to the dominant NO···ON close contacts along the chain surpassing the stacking, H‐bonding and other interactions. Copyright © 2006 John Wiley & Sons, Ltd.
A new method for the determination of cooperative hydrogen bonding enthalpy of proton acceptors with associated species of alcohols
Authors: Solomonov Boris N. , Varfolomeev Mikhail A. , Novikov Vladimir B.
Published: May 2006

A calorimetric method for the determination of cooperative hydrogen bonding (HB) enthalpy of protonacceptors (B) with associated species of alcohols is proposed. The average enthalpy of cooperative HB ofpyridine with associated species of alcohols was found to be −19.8 ± 0.6 kJ mol−1 for all alcohols investigated. Thisvalue exceeds the enthalpy of HB in the complex ROH … NC5H5 (the average for all alcohols is −15.8 ± 0.2 kJ mol−1) by 20–30%. Cooperativity factors (Ab, AOx) of hydrogen bonds for (ROH)2 … NC5H5 complexes were determined using the IR‐spectroscopic method. The average values for the alcohols under consideration were found to be Ab = 1.41 ± 0.04 and AOx = 1.54 ± 0.05. On the basis of IR‐spectroscopic and calorimetric data, the enthalpy of cooperative interactions of pyridine with the dimer (ROH)2 was estimated. This value for all the alcohols studied is, on average, −20.9 ± 0.1 kJ mol−1. Copyright © 2006 John Wiley & Sons, Ltd.
Long‐range polar and steric effects in propionate‐SG1‐type alkoxyamines (SG1‐CHMeCOOX): a multiparameter analysis
Authors: Ananchenko Gennady , Beaudoin Emmanuel , Bertin Denis , Gigmes Didier , Lagarde Pierre , Marque Sylvain R. A. , Revalor Eve , Tordo Paul
Published: May 2006

The effects of the substituent X on the homolysis rate constants (kd) of SG1‐propionate type alkoxyamines (SG1‐CHMeCOOX) are analyzed by a multiparametric equation with υ, the steric constant and σI, the polar inductive/field Hammett constant of X. An influence of long‐range polar and steric effects on kd was observed, that is, decrease in kd with increasing size of the X group and increase in kd with increasing polarity of the X group. Copyright © 2006 John Wiley & Sons, Ltd.
Electrostatic model of bond dissociation energies in polyhalogen methanes
Authors: Jaworski Jan S. , Cembor Marek , Koliński Michał
Published: May 2006

Homolytic bond dissociation energy (BDE) for CH and CX (X = F, Cl, or Br) bonds in polyhalogen methanes was successfully correlated with a two‐parameter model describing the repulsion energy of the bonding electron pair with other electrons and its attraction with nuclei, respectively. BDE values for seven molecules were predicted and compared with those calculated by a DFT method. Copyright © 2006 John Wiley & Sons, Ltd.
Catalytic chain‐transfer synthesis of 1,1,2,2‐tetrahydroperfluoroalkyl methacrylate macromonomers
Authors: Romack Timothy J. , Kaur Gurpreet , Weaver Seth F. , Harrelson Sarah K. , Kenward Angela G.
Published: May 2006

The successful catalytic chain‐transfer synthesis of 1,1,2,2‐tetrahydroperfluoroalkyl methacrylate macromonomers with [bis(aqua)bis(difluoroboryl)dimethylglyoximato]cobalt(II) as a catalyst is reported. Fluoroalkyl methacrylate macromonomers were synthesized in acetone with 2,2′‐azobisisobutyronitrile as the initiator. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4136–4141, 2006
Synthesis and photoluminescent and electrochromic properties of aromatic poly(amine amide)s bearing pendent N‐carbazolylphenyl moieties
Authors: Liou Guey‐Sheng , Chen Hwei‐Wen , Yen Hung‐Ju
Published: May 2006

A series of novel poly(amine amide)s (IIa–IIl) with pendent N‐carbazolylphenyl units having inherent viscosities of 0.25–1.06 dL/g were prepared via direct phosphorylation polycondensation from various dicarboxylic acids and a carbazole‐based aromatic diamine. Except for poly(amine amide) IIc, derived from trans‐1,4‐cyclohexanedicarboxylic acid, all the other amorphous poly(amine amide)s were readily soluble in many polar solvents, such as N,N‐dimethylacetamide and N‐methyl‐2‐pyrrolidone (NMP), and could be cast into transparent and flexible films. The aromatic poly (amine amide)s had useful levels of thermal stability associated with relatively high glass‐transition temperatures (268–331 °C), 10% weight loss temperatures in excess of 540 °C, and char yields at 800 °C in nitrogen higher than 60%. These polymers exhibited maximum ultraviolet–visible absorption at 293–361 nm in NMP solutions. Their photoluminescence in NMP solutions exhibited fluorescence emission maxima around 362 and 448–499 nm for aromatic–aliphatic poly(amine amide)s IIa–IIc and aromatic poly (amine amide)s IId–IIl, respectively. The fluorescence quantum yield in NMP solutions ranged from 0.34% for IIj to 4.44% for IIa. The hole‐transporting and electrochromic properties were examined with electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the poly(amine amide) films cast onto an indium tin oxide coated glass substrate exhibited reversible oxidation at 0.81 V and irreversible oxidation redox couples at 1.20 V versus Ag/AgCl in acetonitrile solutions, and they revealed excellent stability of the electrochromic characteristics, with a color change from yellow to green at applied potentials ranging from 0.00 to 1.05 V. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4108–4121, 2006
Multistep and semibatch nitroxide‐mediated controlled free‐radical emulsion polymerization: A significant step toward conceivable industrial processes
Authors: Nicolas Julien , Charleux Bernadette , Magnet Stéphanie
Published: May 2006

Nitroxide‐mediated emulsion polymerizations of n‐butyl acrylate and styrene were performed with a monofunctional, water‐soluble alkoxyamine initiator and a difunctional one. Two different processes were applied, either in two steps or under semibatch conditions. In particular, the polymerization times were strongly reduced, while high conversions and good control over the polymer characteristics were maintained. In all cases, stable latexes were recovered; with the difunctional initiator in particular, they exhibited small particles and narrow particle size distributions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4142–4153, 2006
Influence of substrate treatment on the growth morphology and magnetic anisotropy of epitaxial CrO2 films
Authors: Miao Guo‐Xing , Xiao Gang , Gupta Arunava
Published: May 2006

Epitaxial CrO2 thin films deposited on HF‐cleaned TiO2(100) substrates exhibit very strong strain anisotropy, while those grown without the HF treatment step are essentially strain‐free and display bulk‐like magnetic properties. The HF treatment enhances the surface smoothness of the TiO2(100) substrate thus leading to the growth of epitaxially strained CrO2 films. The magnetic easy axis of these films changes orientation with thickness, switching from the in‐plane c ‐axis direction for relatively thick films to the b ‐axis direction for thinner films (<50 nm). Similarly, over a thickness range, a change of the easy axis direction is also observed with lowering temperature. Ion‐beam irradiation of the substrate surface prior to growth also results in the growth of strained CrO2 films, although the amount of strain is less than that observed for HF‐treated substrates. The magnetic properties as a function of thickness have also been studied for as‐deposited ‘thick’ CrO2 films that are slowly chemically etched down in thickness. Unlike as‐grown thin films below 50 nm thickness that have the easy axis along the b ‐direction, the chemically etched down CrO2 thin films of equivalent thickness retain their easy axis alignment along the c ‐direction, but display a significantly enhanced coercivity. The observed differences in the switching behavior between the as‐deposited films and those that are chemically etched can be qualitatively attributed to changes in the strain relaxation mechanism. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties and carrier dynamics in differently strained GaN epilayers grown on Si by MOVPE
Authors: Lutsenko E. V. , Pavlovskii V. N. , Danilchyk A. V. , Osipov K. A. , Rzheutskii N. V. , Zubialevich V. Z. , Gurskii A. L. , Yablonskii G. P. , Malinauskas T. , Jarašiūnas K. , Kazlauskas K. , Juršėnas S. , Miasojedovas S. , Žukauskas A. , Dikme Y. , Kalisch H. , Jansen R. H. , Schineller B. , Heuken M.
Published: May 2006

Optical properties and carrier dynamics were investigated in a set of samples grown on Si utilizing different layer combinations between the topmost GaN layer and the Si substrate, including AlN/GaN distributed Bragg reflector (DBR) superlattices as well as AlGaN/GaN strain‐reducing layers. The use of the AlN/AlGaN superlattice acting both as buffer layer and as DBR opens the way to control the strain in the upper epitaxial layer in GaN‐based heterostructures grown on Si. It also can lead to a decrease of the concentration of non‐radiative defects in the upper GaN layers, which, in turn, approximately doubles the carrier lifetime and increases the concentration of non‐equilibrium carriers. Carrier lifetimes at high excitation energy densities increased from 50–78 ps to 75–200 ps in the layers with DBR. These effects lead to improved PL efficiency and to an increase of the value of optical gain from 300 cm–1 up to 4000 cm–1. The use of DBR reduces the absorption of light in the Si substrate and may improve the properties of the laser waveguide. All these effects result in a reduction of the laser threshold from 700 to 270 kW/cm2. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mg doping profile in III–N light emitting diodes in close proximity to the active region
Authors: Köhler K. , Perona A. , Maier M. , Wiegert J. , Kunzer M. , Wagner J.
Published: May 2006

We have investigated how in (AlGaIn)N quantum well (QW) light emitting diodes, grown by low‐pressure metal‐organic vapor phase epitaxy, the actual Mg doping profile close to the interface between AlGaN electron barrier and QW active region, known to be affected by both segregation of back diffusion of Mg, can be controlled and adjusted by the appropriate choice of growth parameters. Almost identical Mg doping profiles, and thus electroluminescence efficiencies which are strongly affected by the Mg doping profile, could be achieved for different combinations of Mg precursor flow and growth temperature. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Si‐doped GaN/AlN quantum dot superlattices for optoelectronics at telecommunication wavelengths
Authors: Guillot F. , Tchernycheva M. , Nevou L. , Doyennette L. , Monroy E. , Julien F. H. , Dang Le Si , Remmele T. , Albrecht M. , Shibata T. , Tanaka M.
Published: May 2006

We report on the controlled growth of Si doped GaN/AlN quantum dot (QD) superlattices, in order to tailor their intersubband absorption within the 1.3–1.5 µm telecommunication wavelengths. The QD size is tuned by modifying the amount of GaN in the QDs and the growth temperature. Silicon can be incorporated in the QDs to populate the first electronic level, without significant perturbation of the QD morphology. As a proof of the capability of these structures for infrared detection, a quantum‐dot intersubband photodetector at 1.38 µm with lateral carrier transport is demonstrated. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
LPE growth of AlN from Cu–Al–Ti solution under nitrogen atmosphere
Authors: Kamei K. , Inoue S. , Shirai Y. , Tanaka T. , Okada N. , Yauchi A.
Published: May 2006

Synthesis of single crystalline AlN has long been the subjects of intensive studies since it has exceptional properties suitable for the substrate materials for optoelectronic and electronic devices. The solution growth technique has some advantages over the sublimation growth technique. Its growth temperature is generally much lower than that of the sublimation growth. The obtained crystal is believed to show superior crystallinity since it is grown under nearly equilibrium condition. In the present study we have developed a new solution growth technique using Cu and Ti as solvents under atmospheric pressure of nitrogen. By using this solution, we have grown AlN single crystalline layer on 6H‐SiC substrate at relatively low growth temperatures such as 1600–1800 °C. The thickness of the grown layer was larger than 30 µm. TEM observation revealed the fairly low dislocation density such as 105/cm2 in the obtained AlN layers. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Profiling of light emission of GaN‐based laser diodes with cathodoluminescence
Authors: Godlewski M. , Phillips M. R. , Kazlauskas K. , Czernecki R. , Targowski G. , Perlin P. , Leszczyński M. , Figge S. , Hommel D.
Published: May 2006

Cathodoluminescence is applied for evaluation of in‐plane variations of light emission from GaN‐based laser diode structures. We demonstrate that potential fluctuations affect significantly emission of laser diodes for e‐beam currents above thresholds for a stimulated emission. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Characterization of free standing GaN grown by HVPE on a LiAlO2 substrate
Authors: Wang Lijun , Zeimer U. , Richter E. , Hennig Ch. , Herms M. , Weyers M.
Published: May 2006

A 230 µm thick free standing GaN layer has been grown on a LiAlO2 substrate by hydride vapor phase epitaxy, with the separation of the layer from the substrate occuring spontaneously during cooling down after growth. A strong green luminescence band is observed from the top surface, while from the bottom surface, strong blue and red bands are seen in photoluminescence (PL). The evolution of these luminescence bands with layer thickness was monitored by cross‐sectional cathodoluminescence (CL). PL and CL measurements indicate that the defect structure changes with growing layer thickness. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)