bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhancement of cell recovery for dissociated human embryonic stem cells after cryopreservation
Authors: Xu Xia , Cowley Sally , Flaim Christopher J. , James William , Seymour Lenard W. , Cui Zhanfeng
Published: December 2009

Due to widespread applications of human embryonic stem (hES) cells, it is essential to establish effective protocols for cryopreservation and subsequent culture of hES cells to improve cell recovery. We have developed a new protocol for cryopreservation of dissociated hES cells and subsequent culture. We examined the effects of new formula of freezing solution containing 7.5% dimethylsulfoxide (DMSO) (v/v %) and 2.5% polyethylene glycol (PEG) (w/v %) on cell survival and recovery of hES cells after cryopreservation, and further investigated the role of the combination of Rho‐associated kinase (ROCK) inhibitor and p53 inhibitor on cell recovery during the subsequent culture. Compared with the conventional slow‐freezing method which uses 10% DMSO as a freezing solution and then cultured in the presence of ROCK inhibitor at the first day of culture, we found out that hES cell recovery was significantly enhanced by around 30 % (P < 0.05) by the new freezing solution. Moreover, at the first day of post‐thaw culture, the presence of 10 μM ROCK inhibitor (Y‐27632) and 1 μM pifithrin‐μ together further significantly improved cell recovery by around 20% (P < 0.05) either for feeder‐dependent or feeder‐independent culture. hES cells remained their undifferentiated status after using this novel protocol for cryopreservation and subsequent culture. Furthermore, this protocol is a scalable cryopreservation method for handling large quantities of hES cells. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Active and inactive metabolic pathways in tumor spheroids: Determination by GC–MS
Authors: Hunnewell Michael G. , Forbes Neil S.
Published: December 2009

Active metabolic pathways in three‐dimensional cancer‐cell cultures are potential chemotherapeutic targets that would be effective throughout tumors. Chaotic vasculature creates cellular regions in tumors with distinct metabolic behavior that are only present in aggregate cell masses. To quantify cancer cell metabolism, transformed mouse fibroblasts were grown as spheroids and fed isotopically labeled culture medium. Metabolite uptake and production rates were measured as functions of time. Gas chromatography–mass spectrometry was used to quantify the extent of labeling on amino acids present in cytoplasmic extracts. The labeling pattern identified several active and inactive metabolic pathways: Glutaminolysis was found to be active, and malic enzyme and gluconeogenesis were inactive. Transformed cells in spheroids were also found to actively synthesize serine, cysteine, alanine, aspartate, glutamate, and proline; and not synthesize glutamine. The activities of these pathways suggest that cancer cells consume glutamine for biosynthesis and not to provide cellular energy. Determining active metabolic pathways indicates how cells direct carbon flow and may lead to the discovery of novel molecular targets for anticancer therapy. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2010
Applications of Allylsamarium Bromide as a Grignard Reagent and a Single‐Electron Transfer Reagent in the One‐Pot Synthesis of Dienes and Trienes
Authors: Hu Yuanyuan , Zhao Tao , Zhang Songlin
Published: December 2009

The utility of allylsamarium bromide, both as a nucleophilic reagent and a single‐electron transfer (SET) reagent in the reaction of α‐halo, γ‐halo‐α,β‐unsaturated ketones and esters with allylsamarium bromide is reported for the first time in this paper. From a synthetic point of view, a general, efficient and experimentally simple one‐pot method for the preparation of 1,4‐dienes and trienes is developed. A possible mechanism of the transformation is proposed.
Organocatalytic Asymmetric Synthesis of Organophosphorus Compounds
Authors: Albrecht Łukasz , Albrecht Anna , Krawczyk Henryk , Jørgensen Karl Anker
Published: December 2009

240 Years have passed since the discovery of elemental phosphorus. During that time organophosphorus chemistry has emerged as an interesting and exciting field of research. Recently organophosphorus chemistry has been raised to a new level. Organophosphorus compounds have found applications in asymmetric organocatalysis for the synthesis of optically active compounds of synthetic or biological importance. The aim of this review article is to present recent contributions to this developing field of chemistry and to point out synthetic advantages of methodologies developed so far.
Optimal Configurations of “Capped” β‐Cyclodextrin Dimers in Water Maximise Hydrophobic Association
Authors: Gamieldien M. Riedaa , Maestre Itziar , Jaime Carlos , Naidoo Kevin J.
Published: December 2009

Circular dichroism analysis and proton NMR experiments revealed that solutions of 3‐O‐(2‐methylnaphthyl)‐β‐cyclodextrin form different dimer configurations. The exact nature of the dimer configurations were postulated to be of three types in which these capped cyclodextrins (CDs) are orientated in head‐to‐head and head‐to‐tail arrangements. Here we show from detailed computer simulations and free‐energy calculations on the configurations that the head‐to‐head configuration in which the naphthyl groups are mutually inserted into each other’s CD cavities is the most favoured configuration. This configuration optimises the hydrophobic association of the naphthyl aromatic groups and the ring cavities as well as forming the most inter‐CD hydrogen bonds of the three configurations.
Fine‐needle aspiration cytology of subcutaneous toxoplasmosis: A case report
Authors: Chen Xiaowei , Remotti Fabrizio , Tong Guo‐Xia , Gorczyca Elzbieta , Hamele‐Bena Diane
Published: December 2009

Toxoplasmosis is a common opportunistic infection in patients with AIDS in whom it typically presents as encephalitis, pneumonia, lymphadenitis, and myocarditis. Skin involvement is very rare and, to our best knowledge, Toxoplasma gondii forming a subcutaneous mass has not been reported. Here, we report the findings of an interesting case of subcutaneous toxoplasmosis with the cytological appearance of an inflammatory fibrovascular lesion in a HIV‐positive patient and discuss the differential diagnosis. Diagn. Cytopathol. 2010;38:716–720. © 2009 Wiley‐Liss, Inc.
Mouse ZAR1‐like (XM_359149) colocalizes with mRNA processing components and its dominant‐negative mutant caused two‐cell‐stage embryonic arrest
Authors: Hu Jianjun , Wang Fengchao , Zhu Xiaoquan , Yuan Ye , Ding Mingxiao , Gao Shaorong
Published: December 2009

Maternal effect genes and encoding proteins are necessary for nuclear reprogramming and zygotic genome activation. However, the mechanisms that mediate these functions are largely unknown. Here we identified XM_359149, aZar1‐like gene that is predominantly expressed in oocytes and zygotes, which we designatedZar1‐like(Zar1l). ZAR1L‐EGFP formed multiple cytoplasmic foci in late two‐cell‐stage embryos. Expression of the ZAR1L C‐terminus induced two‐cell‐stage embryonic arrest, accompanied with abnormal methylation of histone H3K4me2/3 and H3K9me2/3, and marked down‐regulation of a group of chromatin modification factors includingDppa2, Dppa4, andPiwil2. When ectopically expressed in somatic cells, ZAR1L colocalized with P‐body components including EIF2C1(AGO1), EIF2C2(AGO2), DDX6 and LSM14A, and germline‐specific chromatoid body components including PIWIL1, PIWIL2, and LIN28. ZAR1L colocalized with ZAR1 and interacted with human LIN28. Our data suggest that ZAR1L and ZAR1 may comprise a novel family of processing‐body/chromatoid‐body components that potentially function as RNA regulators in early embryos. Developmental Dynamics 239:407–424, 2010. © 2009 Wiley‐Liss, Inc.
The formation of the superior and jugular ganglia: Insights into the generation of sensory neurons by the neural crest
Authors: Thompson Hannah , Blentic Aida , Watson Sheona , Begbie Jo , Graham Anthony
Published: December 2009

The superior and jugular ganglia (S/JG) are the proximal ganglia of the IXth and Xth cranial nerves and the sensory neurons of these ganglia are neural crest derived. However, it has been unclear the extent to which their differentiation resembles that of the Dorsal Root Ganglia (DRGs). In the DRGs, neural crest cells undergo neuronal differentiation just after the onset of migration and there is evidence suggesting that these cells are pre‐specified towards a sensory fate. We have analysed sensory neuronal differentiation in the S/JG. We show, in keeping with previous studies, that neuronal differentiation initiates long after the cessation of neural crest migration. We also find no evidence for the existence of migratory neural crest cells pre‐specified towards a sensory phenotype prior to ganglion formation. Rather our results suggest that sensory neuronal differentiation in the S/JG is the result of localised spatiotemporal cues. Developmental Dynamics 239:439–445, 2010. © 2009 Wiley‐Liss, Inc.
Wnt modulators in the biotech pipeline
Authors: Rey Jean‐Philippe , Ellies Debra L.
Published: December 2009

The purpose of this review is to provide a better understanding for the LRP co‐receptor‐mediated Wnt pathway signaling. Using proteomics, we have also subdivided the LRP receptor family into six sub‐families, encompassing the twelve family members. This review includes a discussion of proteins containing a cystine‐knot protein motif (i.e., Sclerostin, Dan, Sostdc1, Vwf, Norrin, Pdgf, Mucin) and discusses how this motif plays a role in mediating Wnt signaling through interactions with LRP. Developmental Dynamics 239:102–114, 2010. © 2009 Wiley‐Liss, Inc.
A perturbation analysis of harmonic generation from saturated elements in power systems
Authors: Kumano Teruhisa
Published: December 2009

Nonlinear phenomena such as saturation of magnetic flux have considerable effects in power systems analysis. It is reported that a failure in a real 500‐kV system triggered islanding operation, where resultant even harmonics caused malfunctions in protective relays. It is also reported that the major origin of this wave distortion is nothing but unidirectional magnetization of the transformer iron core. Time simulation is widely used today to analyze phenomena of this type, but it has basically two shortcomings. One is that the time simulation takes too much computing time in the vicinity of inflection points in the saturation characteristic curve because certain iterative procedures such as N‐R (Newton–Raphson) must be used and such methods tend to be caught in an ill‐conditioned numerical hunting. The other is that such simulation methods sometimes do not aid an intuitive understanding of the studied phenomenon because all of the nonlinear equations are treated in matrix form and are not properly divided into understandable parts, as is done in linear systems.

This paper proposes a new computation scheme that is based on the so‐called perturbation method. Magnetic saturation of iron cores in a generator and a transformer are taken into account. The proposed method has a special feature to deal with the first shortcoming of the N‐R‐based time simulation method stated above. The proposed method does not use an iterative process to reduce the equation residue, but uses perturbation series, so that it is free of the ill‐conditioning problem. The user need only calculate the perturbation terms one by one until the necessary accuracy is attained. In a numerical example treated in the present paper, first‐order perturbation can achieve reasonably high accuracy, which means very fast computing time.
In a numerical study, three nonlinear elements are considered. The calculation results are almost identical to the conventional N‐R‐based time simulation, which shows the validity of the method. The proposed method can be effectively used in screening where many case studies are needed. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(4): 35–42, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20895
Experimental study of a doubly‐fed rotary frequency converter
Authors: Takemoto Yasutoshi , Fujita Goro , Yokoyama Ryuichi , Koyanagi Kaoru , Funabashi Toshihisa
Published: December 2009

Wind power generation using an unlimited, natural energy has been getting attention regarding environmental issues in recent years, and the installed capacity of wind power generation system is increasing at a rapid pace, resulting in deterioration of power quality especially in frequency and voltage. This fact will be a big problem in restricting large capacity of wind farms.

This paper proposes a new frequency converter: rotary frequency converter (RFC) to moderate the electric output from wind generation, which is to be installed between a set of wind generators and a grid, providing a smoothed electric output, promoting the wind power generation introduction. This mainly consists of a synchronous machine and the adjustable‐speed machine. Independent controls of input/output voltage, active power, and reactive power offer electrical separation between the two networks. Experimental study of a prototype model and its characteristics, especially dynamic control, is discussed in this paper. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(4): 26–34, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20922
Total Synthesis of New 8‐(Arylmethyl)berbines
Authors: Valpuesta Maria , Ariza Manuela , Diaz Amelia , Torres Gregorio , Suau Rafael
Published: December 2009

The total synthesis of the natural compound (8S*,14S*)‐8‐(4′‐hydroxybenzyl)‐2,3‐dimethoxyberbin‐10‐ol and its C‐8 epimer has been conveniently developed by making use of the diastereoselective Stevens rearrangement of the corresponding N‐(arylmethyl)berbinium salts as the key step.
REACH‐driven developments in analysis and physicochemistry
Authors: Chaintreau A. , Begnaud F. , Debonneville C. , Keller U.
Published: December 2009

The enforcement of the REACH regulation in the fragrance domain has created new challenges for the analytical and physical chemist. Many chemicals used as perfumery ingredients are hydrophobic, because low‐polar compounds exhibit a higher substantivity (i.e. persistence after application) than do polar compounds. As a result, the usual protocols are often unsuitable and new methods must be developed. Biodegradation studies sometimes call for the quantification of traces of such hydrophobic analytes in complex media (e.g. waste water, aqueous surfactant solutions). Existing sample preparation techniques are either inefficient or time consuming. A new approach is proposed, based on single‐use absorbants, which allows accurate quantification down to the 100 ppb range. This extremely simple technique allows good throughput analyses. Determining the environmental profile of a compound requires the determination of some physical constants. Among these, solubility in water can be obtained from theoretical models or experimentally, but the resulting values may greatly differ as a function of the model or the protocol. Several experimental approaches are critically discussed and compared with a reference technique. The air‐to‐water partition coefficients are determined by using an improved version of the previously developed static‐and‐trapped headspace technique. Copyright © 2009 John Wiley & Sons, Ltd.
Stack Degradation in Dependence of Operation Parameters; the Real‐SOFC Sensitivity Analysis
Authors: de Haart L. G. J. , Mougin J. , Posdziech O. , Kiviaho J. , Menzler N. H.
Published: December 2009

The EU Integrated Project Real‐SOFC aims at improving the understanding of degradation in SOFC stacks, and extending the durability of planar SOFC stacks to degradation rates suitable for stationary application. As part of the Real‐SOFC project, three series of SOFC stacks, each with two or four planar anode‐supported cells, were operated for durations of 3,000 h up to 10,000 h under varying fuel and electrical load conditions. The durability tests on these short stacks were conducted galvanostatically at 800 and 700 °C in dependence of current‐density (0.3, 0.5 or 0.7 A cm–2), of fuel composition (hydrogen: H2 + 3–10% H2O or methane: CH4/H2O (S/C = 2)) and of fuel utilisation (8, 40, 60 or 75%). A pronounced difference in degradation behaviour was observed between the stacks operated at different current densities. The degradation behaviour was, however, not influenced by the choice of fuel (hydrogen or methane) and was hardly influenced by the fuel utilisation. Lowest degradation rates of about 20 mΩ cm2 kh–1 were determined for the tests of a short stack with cells with LSM cathodes operated at 800 °C and a current‐density of 0.3 A cm–2 and of a short stack with cells with LSCF cathodes operated at 700 °C and a current‐density of 0.5 A cm–2. Post‐test characterisation of the cathode with respect to chromium poisoning was performed on cells from several stacks. No clear relationship between the degradation rate of the stacks and amount of Cr incorporated in the cathode could be established. The major difference was a change in microstructure of the cathode in the region near the electrolyte interface; in the stacks operated at lower current densities, the structurally changed zone was clearly thinner than in those stacks operated at higher currents.
Evaluation of the Perovskite (La0.8Sr0.2)0.95Fe0.8Ni0.2O3–δas SOFC Cathode
Authors: Duval S. B. C. , Graule T. , Holtappels P. , Ouweltjes J. P. , Rietveld G.
Published: December 2009

(La1–xSrx)yFe1–zNizO3–δperovskites have been proposed as alternative cathode materials. In this communication the electrochemical characterisation of (La0.8Sr0.2)0.95Fe0.8Ni0.2O3–δtested on symmetrical cells are compared to full cell tests. Significant differences between the test procedures are observed. Area specific resistances below 0.5 Ω cm2at 800 °C indicate a potential of LSFN for SOFC applications. However, the initial performance and long‐term stability are found to be inferior to state‐of‐art La‐Sr Co‐Fe perovskite cathodes.
Pathogenesis of myeloma bone disease
Authors: Roodman G. David
Published: December 2009

Multiple myeloma (MM) is the most common cancer to involve bone with up to 90% of patients developing bone lesions. The bone lesions are purely osteolytic in nature and do not heal in the vast majority of patients. Up to 60% of patients develop pathologic fractures over the course of their disease. Bone disease is a hallmark of MM, and myeloma bone disease differs from bone metastasis caused by other tumors. Although myeloma and other osteolytic metastases induce increased osteoclastic bone destruction, in contrast to other tumors, once myeloma tumor burden exceeds 50% in a local area, osteoblast activity is either severely depressed or absent. The basis for this severe imbalance between increased osteoclastic bone resorption and decreased bone formation has been the topic of intensive investigation over the last several years. These studies have helped to identify novel targets for treating myeloma bone disease and will be discussed in this chapter. J. Cell. Biochem. 109: 283–291, 2010. © 2009 Wiley‐Liss, Inc.
Resveratrol derivative, trans‐3,5,4′‐trimethoxystilbene, exerts antiangiogenic and vascular‐disrupting effects in zebrafish through the downregulation of VEGFR2 and cell‐cycle modulation
Authors: Alex Deepa , Leong Emilia Conceição , Zhang Zai‐Jun , Yan Gloria Tse Ho , Cheng Shuk‐Han , Leong Chi‐Weng , Li Zhen‐Hua , Lam Kai‐Heng , Chan Shun‐Wan , Lee Simon Ming‐Yuen
Published: December 2009

Angiogenesis plays an important role in the development of neoplastic diseases such as cancer. Resveratrol and its derivatives exert antiangiogenic effects, but the mechanisms of their actions remain unclear. The aim of this study was to evaluate the antiangiogenic activity of resveratrol and its derivative trans‐3,5,4′‐trimethoxystilbene in vitro using human umbilical vein endothelial cells (HUVECs) and in vivo using transgenic zebrafish, and to clarify their mechanisms of action in zebrafish by gene expression analysis of the vascular endothelial growth factor (VEGF) receptor (VEGFR2/KDR) and cell‐cycle analysis. trans‐3,5,4′‐Trimethoxystilbene showed significantly more potent antiangiogenic activity than that of resveratrol in both assays. In zebrafish, trans‐3,5,4′‐trimethoxystilbene caused intersegmental vessel regression and downregulated VEGFR2 mRNA expression. Trans‐3,5,4′‐trimethoxystilbene also induced G2/M cell‐cycle arrest, most specifically in endothelial cells of zebrafish embryos. We propose that the antiangiogenic and vascular‐targeting activities of trans‐3,5,4′‐trimethoxystilbene result from the downregulation of VEGFR2 expression and cell‐cycle arrest at G2/M phase. J. Cell. Biochem. 109: 339–346, 2010. © 2009 Wiley‐Liss, Inc.
Human ES and iPS cells as cell sources for the treatment of Parkinson's disease: Current state and problems
Authors: Hwang Dong‐Youn , Kim Dae‐Sung , Kim Dong‐Wook
Published: December 2009

Cell therapy using human embryonic stem cells (hESCs) is a promising therapeutic option for Parkinson's disease (PD), an incurable neurodegenerative disease. A prerequisite for clinical application of hESCs for PD is an efficient and strict differentiation of hESCs into midbrain dopamine (mDA) neuron‐like cells, which would be directly translated into high effectiveness of the therapy with minimum risk of undesirable side effects. Due to fruitful efforts from many laboratories, a variety of strategies for improving efficiency of dopaminergic differentiation from hESCs have been developed, mostly by optimizing culture conditions, genetic modification, and modulating intracellular signaling pathways. The rapid advances in the fields of dopaminergic differentiation of hESCs, prevention of tumor formation, and establishment of safe human induced pluripotent stem cells (hiPSCs) would open the door to highly effective, tumor‐free, and immune rejection‐free cell therapy for PD in the near future. J. Cell. Biochem. 109: 292–301, 2010. © 2009 Wiley‐Liss, Inc.
Two‐ and three‐dimensional prenatal sonographic diagnosis of prune‐belly syndrome
Authors: Chen Lizhu , Cai Ailu , Wang Xiaoguang , Wang Bing , Li Jingyu
Published: December 2009

We report the prenatal diagnosis of 6 cases of Prune‐belly syndrome in the 2nd trimester. The sonographic diagnosis was based on the findings of oligohydramnios, renal anomalies, and a lower abdominal cystic mass representing the abnormal dilatation of the bladder on conventional 2‐dimensional sonographic examination. We discuss the role of Doppler imaging and 3‐dimensional sonography as complementary methods to conventional sonography. Four of our 6 cases were confirmed with associated defects. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2010
Air–Sea fluxes from ICOADS: the construction of a new gridded dataset with uncertainty estimates
Authors: Berry David I. , Kent Elizabeth C.
Published: December 2009

The methods used to calculate a new in situ global dataset of air–sea exchanges, called the NOCS Flux Dataset v2.0, are described. The fluxes have been derived from in situ weather reports from Voluntary Observing Ships (VOS) covering the period 1973–2006. The reports have been adjusted for known biases and residual uncertainties estimated. The dataset is constructed using Optimal Interpolation (OI) using new estimates of random uncertainty in the observations. Daily fields have been calculated on a 1° latitude by 1° longitude grid, each grid box and time step have an associated uncertainty estimate. Monthly fields have been calculated from simple averages of the daily fields and monthly uncertainty estimates from the daily uncertainties, using estimates of the autocorrelation between the daily uncertainty estimates. The uncertainties due to the choice of flux parameterisation have not been accounted for. Bias adjustments applied to the data are shown to reduce trends in the data and to improve the consistency of estimates of air temperature, sea surface temperature (SST) and specific humidity. The bias adjustments also improve the agreement of NOCS v2.0 with independent data from research moorings. Cross‐validation of the dataset suggests that the uncertainty estimates are realistic, but that the uncertainties are probably underestimated in high variability regions and overestimated in regions with lower variability. Copyright © 2009 Royal Meteorological Society
CCSM3 simulated regional effects of anthropogenic aerosols for two contrasting scenarios: rising Asian emissions and global reduction of aerosols
Authors: Zhang Yongxin , Sun Shan , Olsen Seth C. , Dubey Manvendra K. , He Jinhai
Published: December 2009

This paper examines the effects of two largely contrasting aerosol emissions scenarios on regional climate using National Center for Atmospheric Research Community Climate System Model version 3: (1) increasing the anthropogenic aerosols over China and India by a factor of three and (2) reducing the global anthropogenic aerosols by a factor of 10. Dynamic footprints of the increased Asian aerosols with monthly variations are obtained from Model for OZone And Related chemical Tracers simulations. Increasing Asian aerosol emissions would result in cooling and reduction of precipitation over China and India, with large warming over the USA and southern Canada in winter and cooling in summer. Additionally, large changes in rainfall rate are identified over the tropical regions. In contrast, reducing the global aerosol emissions by a factor of 10 would significantly warm the atmosphere especially over the polluted land areas of both hemispheres. Increases in rainfall over polluted land areas are also noted. Deepening of the Aleutian low and weakening of the Icelandic low in winter are noted in the 500‐mb geopotential height under both scenarios suggesting a strengthening of the North Pacific storm track and weakening of the North Atlantic Oscillation. The polar regions of winter hemisphere are subject to large changes in the 500‐mb geopotential height. Teleconnection patterns associated with ENSO play important roles in causing large changes in surface air temperature and rainfall far away from the source regions of the altered aerosol concentrations. Copyright © 2009 Royal Meteorological Society
Characterization of tetragonal SAT0.3: LA0.075: CAT0.625 perovskite crystal: spectroscopic and microscopic investigations
Authors: Runka T. , Diduszko R. , Berkowski M. , Kamiński M. , Łapiński A. , Polomska M. , Drozdowski M.
Published: December 2009

We report room temperature measurements of X‐ray diffraction (XRD), optical transmission microscopy (OTM), atomic force microscopy (AFM), infrared‐absorption (IR), and micro‐Raman spectroscopy (µ‐RS) of the oriented SAT0.3: LA0.075: CAT0.625 single crystal. The final structure refinement of SAT0.3: LA0.075: CAT0.625 crystal was performed for I4/m space group at room temperature. Vibrational spectra of the crystal were discussed in terms of group‐theoretical predictions for untilted (Fm3m) and tilted tetragonal (I4/m) perovskite structure. The confocal µ‐Raman measurements of depth profiling of SAT0.3: LA0.075: CAT0.625 crystal suggest a relationship between sensitivities of the ordering‐related Raman‐active modes and the variation of order parameter η. Copyright © 2009 John Wiley & Sons, Ltd.
Immunogold labelling to localize polyphenol oxidase (PPO) during wilting of red clover leaf tissue and the effect of removing cellular matrices on PPO protection of glycerol‐based lipid in the rumen
Authors: Lee Michael RF , Tweed John KS , Cookson A , Sullivan ML
Published: December 2009

BACKGROUND: The enzyme polyphenol oxidase (PPO) reduces the extent of proteolysis and lipolysis within red clover fed to ruminants. PPO catalyses the conversion of phenols to quinones, which can react with nucleophilic cellular constituents (e.g. proteins) forming protein–phenol complexes that may reduce protein solubility, bioavailability to rumen microbes and deactivate plant enzymes. In this study, we localized PPO in red clover leaf tissue by immunogold labelling and investigated whether red clover lipid was protected in the absence of PPO‐induced protein–phenol complexes and plant enzymes (lipases).

RESULTS: PPO protein was detected to a greater extent (P < 0.001) within the chloroplasts of mesophyll cells in stressed (cut/crushed and wilted for 1 h) than freshly cut leaves for both palisade (61.6 and 25.6 Au label per chloroplast, respectively) and spongy mesophyll cells (94.5 and 40.6 Au label per chloroplast, respectively). Hydrolysis of lipid and C18 polyunsaturated fatty acid biohydrogenation during in vitro batch culture was lower (P < 0.05) for wild‐type red clover than for red clover with PPO expression reduced to undetectable levels but only when cellular matrices containing protein–phenol complexes were present.

CONCLUSION: Damaging of the leaves resulted in over a doubling of PPO detected within mesophyll cells, potentially as a consequence of conversion of the enzyme from latent to active form. PPO reduction of microbial lipolysis was apparent in macerated red clover tissue but not in the absence of the proteinaceous cellular matrix, suggesting that the PPO mechanism for reducing lipolysis may be primarily through the entrapment of lipid within protein–phenol complexes. Copyright © 2009 Society of Chemical Industry
The role of chlorine atoms and hydroxyl radicals in the formation of PCDDs from the oxidative pyrolysis of 2,4,6‐trichlorophenol
Authors: Khachatryan Lavrent , Burcat Alexander , Dellinger Barry
Published: December 2009

A 132‐step gas‐phase reaction kinetic model has been combined with a four‐step surface model for the formation of 1,3,6,8‐tetrachlorodibenzo‐p‐dioxin (1,3,6,8‐TCDD) from the oxidation of 2,4,6‐trichlorophenol (2,4,6‐TCP) in the presence of hexane. The revised model is based on a simpler model previously published in the literature and modified by adding Cl‐releasing and the surface submodels, recalculating polynomial functions for thermodynamic parameters, and updating gas‐phase submodels for (i) 1,3,6,8‐TCDD formation, (ii) hydrogen oxidation, and (iii) hexane oxidation. The roles of the potential chain carriers, OH and Cl, in the formation of 1,3,6,8‐TCDD were specifically addressed. In spite of the reported high reactivity of Cl, it was found that OH:Cl ≫ 1, and OH is the dominant chain carrier from the apparent onset of purely gas‐phase reactions at 750 K to 99% conversion of 2,4,6‐TCP and hexane at 1075 K. This suggests that oxidation reactions are always dominant in realistic combustion systems, even where there are high concentrations of chlorine and relatively rich burning conditions. The update of the three gas‐phase submodels as well as incorporation of Cl‐releasing and the surface submodels resulted in improved agreement between calculated and experimental yields of 1,3,6,8‐TCDD yields at temperatures as low as 800 K. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 42: 90–97, 2010
Rate coefficients and products for gas‐phase reactions of chlorine atoms with cyclic unsaturated hydrocarbons at 298 K
Authors: Sharma A. , Pushpa K. K. , Dhanya S. , Naik P. D. , Bajaj P. N.
Published: December 2009

Rate coefficients for the reaction of Cl atoms with cycloalkenes have been determined using the relative rate method, at 298 K and atmospheric pressure of N2. Reference molecule wasn‐hexane, and the concentrations of the organics were followed by gas chromatographic analysis. Cl atoms were prepared by photolysis of trichloroacetyl chloride at 254 nm. The relative rates of reactions of Cl atoms with cycloalkenes, with respect ton‐hexane, are measured as 1.12 ± 0.38, 1.31 ± 0.14, and 1.69 ± 0.18 for cyclopentene, cyclohexene, and cycloheptene, respectively. Considering the absolute value of the rate coefficient of the reaction of Cl atom withn‐hexane as 3.03 ± 0.06 × 10−10cm3molecule−1s−1, the rate coefficient values for cyclopentene, cyclohexene, and cycloheptene are calculated to be (3.39 ± 1.08) × 10−10, (3.97 ± 0.43) × 10−10, and (5.12 ± 0.55) × 10−10cm3molecule−1s−1, respectively. The experiments for each molecule were repeated six to eight times, and the slopes and the rate coefficients given above are the average values of these measurements, and the quoted error includes 2σ as well as all other uncertainties in the measurement and calculations. The rate coefficient increases linearly with the number of carbon atoms, with an increment per additional CH2group being (8.7 ± 1.6) × 10−12cm3molecule−1s−1. Chloroketones and chloroalcohols, along with unsaturated ketones and alcohols, were found to be the major products of Cl‐atom‐initiated oxidation of cycloalkenes in the presence of air. The atmospheric implications of these results are discussed, along with a comparison with the reported structure activity relationships. © 2009 Wiley Periodicals, Inc. Int J Chem Kinet 42: 98–105, 2010
Molecular Aspects of Radical Polymerizations—The Propagation Frequency
Authors: Tauer Klaus , Hernandez Hugo F.
Published: December 2009

The product of the propagation rate constant and monomer concentration is a central issue of radical polymerization. Both quantities are strongly interrelated as the determination of a reliable value of the propagation rate constant requires exact knowledge of the monomer concentration. Even for homogeneous polymerization conditions, exact knowledge of the monomer concentration at the reaction site from the molecular perspective is not trivial. For emulsion polymerizations the situation is additionally complicated by mass transfer events and colloid‐chemical effects. Molecular modeling appears as an attractive alternative or complement to the deterministic kinetic description of radical polymerizations.

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Polymer Incompatibility Caused by Different Molecular Architectures: Modeling via Chain Connectivity and Conformational Relaxation
Authors: Wolf Bernhard A.
Published: December 2009

The calculation of phase diagrams for blends of linear and branched polymers made up of identical monomeric units is modeled using an approach that subdivides the mixing process into two steps: i) contact formation between the different components, keeping their chain conformations and the volume of the system constant; and, ii) relaxation of the macromolecules into their equilibrium state by molecular rearrangements. It is assumed that step (ii) causes shape‐induced polymer incompatibility and that the degree of branching can be quantified in terms of the volumes the isolated coils of the branched polymer occupy in relation to the volume the linear product with the same molecular weight occupies. Under these premises, it is possible to work out how the critical conditions depend on the molar masses of the components and on the degree of branching of the non‐linear polymer by means of only one system‐specific parameter, measuring the effects of conformational relaxation. Detailed phase diagrams show how the binodal and spinodal conditions reflect the conformational variability of the blend components.

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Verbundstrangpressen von Titan‐Aluminium‐Verbindungen
Authors: Grittner N. , von Senden gen. Haverkamp H. , Stelling O. , Bormann D. , Schimanski K. , Nikolaus M. , von Hehl A. , Bach Fr.‐W. , Zoch H.‐W.
Published: December 2009

Durch die Kombination von unterschiedlichen metallischen Werkstoffen lassen sich maßgeschneiderte Konstruktionen mit optimierten Eigenschaften herstellen. Die Herstellung von Werkstoffverbunden ist jedoch häufig mit hohen Anforderungen an die Fertigungstechnik verbunden. Schwerpunkt dieser Untersuchung ist das Verbundstrangpressen von Aluminium und Titan. Neben den mechanischen Eigenschaften des Verbundes wurden die Ausbildung der Bindungszone sowie die beim Haftungsaufbau wirksamen Bindungsmechanismen untersucht. Hierbei war neben dem Einfluss der Probenvorbereitung vor allem die Wirksamkeit von unterschiedlichen Haftvermittlerschichten von Interesse. Während Schichten aus Kupfer oder Nickel den Haftungsaufbau aufgrund von Oxidschichtbildung verhindern, können durch Umformung eingegossener Titankerne Festigkeiten von über 100 MPa erreicht werden. Im Vergleich zu alternativen Fügeverfahren tritt eine Beeinträchtigung des Werkstoffgefüges in Form von Wärmeeinflusszonen, Porenbildung oder Grobkornbildung hier nicht auf.
Influence of glyoxal on localized corrosion of austenitic stainless steel in spring water
Authors: Alar V. , Juraga I. , Runje B. , Alar Ž.
Published: December 2009

This paper presents the research regarding the influence of glyoxal on electrochemical and corrosion behaviour of austenitic stainless steel in water. For this purpose, model solutions containing glyoxal in water in concentrations ranging from 0.1 to 1 % were prepared. Spring water was used as control electrolyte. From the potentiostatic polarisation data (using the standard three‐electrode system), the corrosion current (icorr), corrosion potential (Ecorr) and polarisation resistance (Rp) were calculated. The research included also the conductivity, total dissolved soils, salinity, resistivity and pH, absolute potential, and relative potential of model solutions. The presence of glyoxal at the highest concentration of 1 % in the water solution has accelerating effect on corrosion.
Processing and characterization of a cobalt based alloy for use in diamond cutting tools
Authors: de Oliveira H.C.P. , Cabral S.C. , Guimarães R.S. , Bobrovnitchii G.S. , Filgueira M.
Published: December 2009

Most of the alloys used as bonding matrix in diamond tools show a high content of cobalt ‐ which is undesirable due to a series of reasons. In the last decade, some attempts were made towards the reduction of the Co content in these alloys. NEXT100® alloy (50wt%Cu‐25wt%Fe‐25wt%Co) by Eurotungstene is an example of it.

This study aims to characterize the structure, microstructure and some mechanical properties of the NEXT100 ‐ this is an comercial alloy widely used as bonding matrix for diamonds in cutting tools, and the informations about its properties are very scarce in the literature.

The NEXT100 powder was hot pressed in a graphite matrix at 35MPa/800 °C/3 minutes. It was performed structural and microstructural analyses by x‐ray diffraction and scanning electon microscopy, respectivelly. Wear resistance and hardness HRB tests were carried out – these are the most important mechanical tests for a diamond bonding matrix. It was demonstrated that the samples presented good mechanical properties, XRD analysis showed the presence of two phases, Cu (CFC) and the solid solution α‐Fe (CCC). Microstructural aspects are high densification, homogeneous distribution of phases, and little presence of pores.
Elektronenstrahlschweißen von massiven metallischen Gläsern
Authors: Reisgen U. , Balashov B. , Holk J. , Geffers C. , Kühn U.
Published: December 2009

Massive metallische Gläser stellen u. a. wegen ihrer hervorragenden mechanisch‐technologischen Eigenschaften eine vielversprechende, vergleichsweise neue Gruppe von Werkstoffen dar. Durch ihre geringe thermische Stabilität sind der Schweißbarkeit metallischer Gläser enge Grenzen gesetzt, wenn eine Kristallisation der Fügezone vermieden werden soll. Der vorliegende Artikel beschreibt den aktuellen Stand der Forschungsarbeiten zum Elektronenstrahlschweißen berylliumfreier massiver metallischer Gläser auf Zirkoniumbasis (Zr52,5Ti5Cu17,9Ni14,6Al10) am Institut für Schweißtechnik und Fügetechnik der RWTH Aachen. Bei den bisherigen Untersuchungen konnten fehlerfreie, qualitativ hochwertige Schweißverbindungen erzeugt werden, allerdings ist es bisher noch nicht gelungen, die Kristallisation der Fügezone vollständig zu unterdrücken. Weitere Untersuchungen dazu laufen.
Chemisches Abscheiden von NiP‐Nanokomposit‐schichten
Authors: Dünkel K. , Meyer D. , Lampke T. , Steinhäuser S.
Published: December 2009

Die elektrolytische und chemische Abscheidung von nickelbasierten Nanokompositen steht im Fokus weltweiter Forschungsaktivitäten. Ursache hierfür sind einerseits die aufgrund des minimalen Volumens in den Vordergrund rückenden Oberflächeneigenschaften nanoskaliger Verstärkungskomponenten. Andererseits bieten nanoskalige Partikel technologische Vorteile bei der Realisierung sehr dünner Schichten beispielsweise für die Mikrosystemtechnik. Jedoch ist bei chemischer Abscheidung im Vergleich zu elektrolytischer Abscheidung nur eine begrenzte Übertragbarkeit der Prozessparameter von mikro‐ zu nanoskaligen Dispersionsschichten gegeben. Dieser Artikel beschäftigt sich daher mit der Entwicklung und Modifizierung von Prozessen zur stabilen chemischen Abscheidung von NiP‐Dispersionsschichten mit nanoskaliger Verstärkungskomponente sowie deren Wirkung auf ausgewählte Schichteigenschaften (Härte, photokatalytische Aktivität). Das Ziel eines homogenen und feindispersen Einbaus der Partikel wurde weitgehend erreicht. Zudem wurde die Wirkung von Ultraschall auf die Einbaurate und das Desagglomerationsvermögen untersucht.
Herstellung und komplexe Charakterisierung von Metall‐Keramik‐Verbundschichten
Authors: Kups T. , Knote A. , Krüger H.‐G. , Winkler H.‐V. , Kern H. , Spieß L.
Published: December 2009

In dieser Arbeit wird der Einfluss der Herstellungsbedingungen und ‐materialien von Metall‐Keramik‐Verbundschichten auf die strukturellen Eigenschaften der Schichten untersucht und optimiert, um insbesondere die mechanischen Eigenschaften zu erhöhen. Dabei erfolgte die Abscheidung der Metall‐Keramik‐Verbundschichten durch eine Verfahrenskombination von elektrophoretischer und galvanischer Abscheidung unter zu Hilfenahme von Siloxan als Bindemittel. Es konnten somit Schichten mit einem hohen Keramikgehalt erfolgreich hergestellt werden. Als keramische Komponenten wurden kommerzielle Siliciumkarbid‐ und Siliciumnitrid‐Partikel eingesetzt. Als metallische Komponenten um die poröse keramische Schicht aufzufüllen und die Struktur zu festigen, kamen Nickel bzw. Kupfer zum Einsatz, wobei eine Vorvernickelung bzw. Vorverkupferung des Stahl‐Substrats (X6Cr17) erforderlich war, um die gewünschten Eigenschaften hinsichtlich der Haftfestigkeit der Schichten zu erhalten. Die Charakterisierung erfolgte mittels optischer Mikroskopie und Raster‐ und Transmissionselektronenmikroskopie (REM, TEM), wo besonders die Ausbildung der Verbindung der einzelnen Partikel durch das Siloxan deutlich wurde.
Minocycline 1‐year therapy in multiple‐system‐atrophy: Effect on clinical symptoms and [11C] (R)‐PK11195 PET (MEMSA‐trial)
Authors: Dodel Richard , Spottke Annika , Gerhard Alexander , Reuss Alexander , Reinecker Sylvia , Schimke Nicole , Trenkwalder Claudia , Sixel‐Döring Friederike , Herting Birgit , Kamm Christoph , Gasser Thomas , Sawires Martin , Geser Felix , Köllensperger Martin , Seppi Klaus , Kloss Manja , Krause Martin , Daniels Christine , Deuschl Günther , Böttger Silke , Naumann Markus , Lipp Axel , Gruber Doreen , Kupsch Andreas , Du Yansheng , Turkheimer Federico , Brooks David J. , Klockgether Thomas , Poewe Werner , Wenning Gregor , Schade‐Brittinger Carmen , Oertel Wolfgang H. , Eggert Karla
Published: December 2009

The aim of the study was to investigate the efficacy of the antibiotic minocycline as a drug treatment in patients with Multiple‐System‐Atrophy Parkinson‐type (MSA‐P). Sixty‐three patients were randomized to minocycline 200 mg/d (n = 32) or a matching placebo (n = 31). The primary outcome variable was the change in the value of the motor score of the Unified Multiple‐System‐Atrophy Rating‐Scale (UMSARSII) from baseline to 48 weeks. Secondary outcome variables included subscores and individual Parkinsonian symptoms as determined by the UMSARS and the Unified‐Parkinson's‐Disease Rating‐Scale (UPDRS). Health‐related quality of life (HrQoL) was assessed using the EQ‐5D and SF‐12. “Progression rate” was assumed to be reflected in the change in motor function over 48 weeks. At 24 weeks and 48 weeks of follow‐up, there was a significant deterioration in motor scores in both groups, but neither the change in UMSARSII nor in UPDRSIII differed significantly between treatment groups, i.e. “progression rate” was considered to be similar in both treatment arms. HrQoL did not differ among the two treatment arms. In a small subgroup of patients (n = 8; minocycline = 3, placebo = 5)[11C](R)‐PK11195‐PET was performed. The three patients in the minocycline group had an attenuated mean increase in microglial activation as compared to the placebo group (P = 0.07) and in two of them individually showed decreased [11C](R)‐PK11195 binding actually decreased. These preliminary PET‐data suggest that minocycline may interfere with microglial activation. The relevance of this observation requires further investigation. This prospective, 48 week, randomized, double‐blind, multinational study failed to show a clinical effect of minocycline on symptom severity as assessed by clinical motor function. © 2009 Movement Disorder Society
Baroreflex sensitivity and power spectral analysis during autonomic testing in different extrapyramidal syndromes
Authors: Friedrich Constanze , Rüdiger Heinz , Schmidt Claudia , Herting Birgit , Prieur Silke , Junghanns Susann , Schweitzer Katherine , Globas Christoph , Schöls Ludger , Berg Daniela , Reichmann Heinz , Ziemssen Tjalf
Published: December 2009

Autonomic dysfunction has been frequently demonstrated in patients with extrapyramidal diseases by cardiovascular autonomic testing. In addition to classical testing, we applied the more detailed baroreflex and spectral analysis on three traditional cardiovascular tests in this study to get additional information on autonomic outflow. We recorded continuously blood pressure, electrocardiogram, and respiration in 35 patients with multiple system atrophy, 32 patients with progressive supranuclear palsy, 46 patients with idiopathic Parkinson's disease and in 27 corresponding healthy subjects during cardiovascular autonomic testing (metronomic breathing, Valsalva manoeuvre, head‐up tilt). Baroreflex and spectral analyses were performed by using trigonometric regressive spectral analysis between and during the manoeuvres. Consistent with previous interpretations, our data showed an increase of sympathetic activity in head‐up tilt and Valsalva test in healthy controls. This sympathetic activity was significantly decreased in patients with typical and atypical Parkinson syndromes. Significant modulation of baroreflex activity could be observed especially during metronomic breathing; again it was significantly lower in all patient groups. Baroreflex and spectral parameters could not only differentiate between patients and healthy controls, but also differentiate between clinically symptomatic (with autonomic dysfunction as eg. orthostatic hypotension) and asymptomatic patients. In conclusion, our approach allows the evaluation of autonomic variability during short and nonstationary periods of time and may constitute a useful advance in the assessment of autonomic function in both physiological and pathological conditions. © 2009 Movement Disorder Society