bluuebunny/crossref_metadata_2025_split huggingface dataset:
Methionine‐dependence phenotype of tumors: Metabolite profiling in a melanoma model usingL‐[methyl‐13C]methionine and high‐resolution magic angle spinning1H–13C nuclear magnetic resonance spectroscopy
Authors: Morvan Daniel , Demidem Aicha , Guenin Samuel , Madelmont Jean Claude 
Published: April 2006

AbstractTumors frequently have abnormalL‐methionine (Met) metabolism, the so‐called Met‐dependence phenotype that refers to the inability to proliferate in the absence of Met. However, the origin of this phenotype is still unknown and may arise from one of several pathways of Met metabolism. To help characterize the metabolic features of Met‐dependent/independent phenotypes, the fate of the methyl carbon ofL‐[methyl‐13C]Met was chased in a murine model of malignant melanoma (B16‐F1) in vitro and in vivo. Growth curves under Met restriction showed that melanoma cells in vitro were Met‐independent, whereas implanted melanoma tumors in vivo were Met‐dependent. Label‐assisted high‐resolution magic angle spinning1H‐13C NMR spectroscopy metabolite profiling showed that, in vitro, creatine and phosphatidylcholine13C‐enrichments were poor, butS‐adenosyl‐Met and posttranslationally N‐methylated protein signals were strong. In contrast, in vivo, creatine and phosphatidylcholine enrichments were strong butS‐adenosyl‐Met and N‐methylated protein signals were poor. In addition, in vivo, transsulfuration was very efficient, consumed one‐carbon units originating from the methyl carbon of Met, and yielded taurine labeling. From these data, the Met‐dependent/independent phenotypes appear closely related to the source of one‐carbon units. Thus,L‐[methyl‐13C]Met‐assisted NMR spectroscopy metabolite profiling allowed the discrimination between Met‐dependence and Met‐independence and provided novel mechanistic information on their origin. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Bolus delay and dispersion in perfusion MRI: Implications for tissue predictor models in stroke
Authors: Calamante Fernando , Willats Lisa , Gadian David G. , Connelly Alan 
Published: April 2006

AbstractPerfusion maps, which are calculated from dynamic‐susceptibility contrast (DSC)‐MRI data by deconvolution of the arterial input function (AIF), are commonly used to predict tissue infarction in acute stroke. However, since the AIF is commonly measured in a major artery, there can be perfusion measurement errors associated with bolus delay/dispersion. Although methods to account for delay‐related errors have been proposed, the effect of dispersion is more difficult to deal with and is usually left uncorrected. This study presents an assessment of the delay–dispersion relationship in a group of patients. Although a significant correlation was observed with one of the bolus delay definitions used, the estimation of the dispersion from the degree of delay was unreliable. Importantly, the dispersion observed in many patients was sufficient to result in substantial perfusion errors. The results are compared with previous numerical simulations, and their implications for the assessment and management of acute stroke are discussed. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
MRI analysis of angiogenesis during mouse embryo implantation
Authors: Plaks Vicki , Kalchenko Vyacheslav , Dekel Nava , Neeman Michal 
Published: April 2006

AbstractUterine receptivity and embryo implantation depend on local induction of angiogenesis and vascular permeability. Poor uterine receptivity has been implicated in implantation failure; however, relatively little is known about the mechanism that underlies endometrial vascular hyperpermeability in implantation sites. Here we show that contrast‐enhanced (CE)‐MRI and fluorescence microscopy using biotin‐BSA‐GdDTPA allowed high‐resolution detection and quantitative assessment of mouse embryo implantation sites as early as embryonic day 4.5 (E4.5), and subsequent vascular expansion at E5.5. Vessel permeability, but not blood volume, was significantly elevated in E4.5 implantation sites relative to nonimplanted uterus, showing that elevation of vascular permeability is a very early response preceding E4.5. A significantly increased blood volume was detected by MRI and fluorescence microscopy in implantation sites between E4.5 and E5.5. On the other hand, despite the increase in blood volume, implantation sites showed only a small nonsignificant further increase in vascular permeability during these 2 days, demonstrating the rapid dynamics of vascular remodeling during the early days of pregnancy. Functional imaging by MRI, as reported here, allows multiparametric measurement of angiogenesis during normal mouse implantation and would facilitate the application of MRI to evaluate involvement of the vasculature in mouse models of impaired implantation. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
MR susceptometry for measuring global brain oxygen extraction
Authors: Fernández‐Seara María A. , Techawiboonwong Aranee , Detre John A. , Wehrli Felix W. 
Published: April 2006

AbstractMonitoring of oxygen saturation in jugular venous blood gives an estimate of the balance of global oxygen delivery and cerebral oxygen consumption. We present a noninvasive approach to measure oxygen saturation in vivo in the internal jugular vein using MR susceptometry by exploiting the characteristic susceptibility of deoxyhemoglobin, and demonstrate the feasibility of performing such measurements in a group of subjects. We assessed the sensitivity of the method for detecting small changes in oxygen saturation by monitoring the variations observed during breath‐holding and hypoventilation experiments. Unlike alternative methods, the susceptometric technique does not require calibration. Magn Reson Med, 2006. © 2006 Wiley‐Liss, Inc.
Utrophin is a calpain substrate in muscle cells
Authors: Courdier‐Fruh Isabelle , Briguet Alexandre 
Published: April 2006

AbstractCalpains are Ca2+‐dependent cytosolic cysteine proteases that participate in the pathology of Duchenne muscular dystrophy (DMD). Utrophin is a functional homolog of dystrophin that partially compensates for dystrophin deficiency in myofibers of mdx mice. In this study, we investigated the susceptibility of utrophin to cleavage by calpain in vitro and in muscle cells. We found that utrophin is a direct in vitro substrate of purified calpain I and II. Cleavage of utrophin by calpain I or II generates specific degradation products that are also found in cultured control and DMD myotubes under conditions with elevated intracellular Ca2+ levels. In addition, we showed that activation of cellular calpains by Ca2+ ionophore treatment reduces utrophin protein levels in muscle cells and that calpain inhibition prevents this Ca2+‐induced reduction in utrophin levels. These observations suggest that, beside its known effect on general muscle protein degradation, calpain contributes to DMD pathology by specifically degrading the compensatory protein utrophin. Muscle Nerve, 2006
SNMP GetRows: an effective scheme for retrieving management information from MIB tables
Authors: Chen Yen‐Cheng , Chan Io‐Kuan 
Published: April 2006

AbstractManagement information accessible via SNMP is organized in the Management Information Base (MIB). Many management applications are based on management information within an MIB table. The management information useful for management applications may be located in some rows of an MIB table. Owing to the limitation of current SNMP GetNext and GetBulk services, it is usually inevitable to retrieve all the rows of an MIB table even if some of them are needed. As the size of the MIB table grows, the object retrieval will incur considerable bandwidth and latency. Without loss of the simplicity of SNMP, we propose a novel SNMP service, called GetRows, to provide the capability of object selection via SNMP. Using GetRows, a management application can specify criteria for evaluating rows of an MIB table. Only the object instances in the rows selected by the criteria will be retrieved. Thus, less bandwidth and latency can be achieved by using the proposed GetRows service. Copyright © 2006 John Wiley & Sons, Ltd.
Improved outcome in childhood acute myeloid leukemia in Singapore with the MRC AML 10 protocol
Authors: Tan Ronald M. , Quah Thuan Chong , Aung LeLe , Liang Shen , Kirk Richard C. , Yeoh Allen E.J. 
Published: April 2006

AbstractBackgroundThe introduction of the United Kingdom Medical Research Council's 10th AML trial (MRC AML 10) protocol incorporating high‐dose anthracycline therapy has improved outcome of children with acute myeloid leukemia (AML). In this study, we review the results of childhood AML therapy in a Singapore university hospital over the last 17 years emphasizing toxicity and outcome.ProcedureRetrospective analysis revealed 34 children with AML between 1988 and 2003. Prior to September 1996, therapy consisted of: POG‐8498 (n = 10), others (n = 9). From September 1996, all but one of 15 children received MRC AML 10 treatment.ResultsAt the time of analysis, 17 had died from disease, and 17 patients were alive among whom 2 had relapsed. MRC AML 10‐treated patients (n = 14) had significantly better 3‐year overall, event‐free, and disease‐free survival (74% vs. 35%, 77% vs. 20%, 83% vs. 31%; P = 0.019, P = 0.002, and P = 0.010, respectively) and were likelier to achieve complete remission (CR) than non‐MRC AML 10 patients (P = 0.102). Among patients who achieved CR, MRC AML 10‐treated patients were significantly more likely to achieve CR after only one cycle of chemotherapy (P = 0.016). Hematologic toxicity was similar among the different regimens (P = 0.9).ConclusionsThese findings suggest that MRC AML 10 treatment results in significantly superior survival, without excess toxicity. Future studies should attempt to elucidate the relative importance of individual MRC AML 10 components and reduce the high cumulative anthracycline dose without compromising outcome. Pediatr Blood Cancer 2007;48:262–267. © 2006 Wiley‐Liss, Inc.
Overview of the preparation of pure polyaniline and conductive composites in dispersed media and by thermal processes: from laboratory to semi‐industrial scale
Authors: Kohut‐Svelko Nicolas , Dinant Frédéric , Magana Sylvain , Clisson Gérald , François Jeanne , Dagron‐Lartigau Christine , Reynaud Stéphanie 
Published: April 2006

AbstractIntrinsically conductive polymers (ICPs) and conductive composites offer many potential industrial applications due to their conductive properties, processability and mechanical properties. Much work has been carried out to develop the synthesis and formulation of various conductive polymers. Nevertheless, polyaniline (PANI) seems to be one of the most interesting conductive polymer based on the low cost of its synthesis, its conductive properties and its thermal and environmental stability. In this paper, we describe the synthesis and formulation of conductive composites containing PANI by considering two synthetic approaches. The first one is based on the oxidative polymerization of aniline. This synthesis has been optimized from laboratory‐scale to a 50 L pilot‐plant reactor. After a post‐doping procedure, the composite is obtained using a twin‐screw extruder. The second approach concerns a core/shell synthesis (polymer matrix/PANI) procedure which allows synthesis and formulation at the same time. Conductive composites of various compositions (polymer matrix/PANI content and additives) were synthesized by both of these methods and the advantages and drawbacks of each of them are discussed. Copyright © 2006 Society of Chemical Industry
Reactivity control in anionic polymerization of ethylenic and heterocyclic monomers through formation of ‘ate’ complexes
Authors: Carlotti Stéphane , Desbois Philippe , Billouard Cyrille , Deffieux Alain 
Published: April 2006

AbstractThe reactivity and selectivity of active species are the key parameters in the design of living/controlled polymerizations. We have shown that alkyl metal derivatives, such as dialkylmagnesium or trialkylaluminum derivatives, when used as additives to conventional anionic polymerization systems, are very effective mediators for the polymerization control of both ethylenic and heterocyclic monomers. When added to alkali metal alkyl initiators, typically alkyl lithium, for styrene and dienes anionic polymerization they strongly retard the reactivity of the polystyryl and polybutadienyl propagating species and allow control of the polymerization of styrene under very unusual conditions (bulk, very high temperatures). On the contrary, when used in combination with quite similar alkali‐metal‐based initiators in the anionic polymerization of ethylene oxide or propylene oxide, these additives drastically enhance the reactivity and the selectivity of the involved propagating species, thus allowing a fast ‘living‐like’ polymerization to proceed at low temperatures in hydrocarbon media. Copyright © 2006 Society of Chemical Industry
A novel approach to the preparation of thermoplastic polyurethane elastomer and polyamide 6 blends by in situ anionic ring‐opening polymerization of ε‐caprolactam
Authors: Hou Lian‐Long , Liu Hong‐Zhi , Yang Gui‐Sheng 
Published: April 2006

AbstractBlends of thermoplastic polyether‐based urethane elastomer (TPEU) and monomer casting polyamide 6 (MCPA6) were prepared using ε‐caprolactam as reactive solvent, with caprolactam sodium as a catalyst in the presence of TPEU, with TPEU content varying from 2.5% to 10% by weight. In situ anionic ring‐opening polymerization and in situ compatibilization to prepare TPEU/MCPA6 blends were carried out in one step. The TPEU chains, which underwent thermal dissociation in amine solvents to bear isocyanate groups, acted as macroactivator to initiate MCPA6 chain growth from the TPEU chains and form graft copolymers of TPEU‐co‐MCPA6 to improve compatibility between TPEU and MCPA6. The structure and thermal properties were characterized by means of Fourier transform infrared spectroscopy, 1H‐NMR spectroscopy, differential scanning calorimetry and scanning electron microscopy. Copyright © 2006 Society of Chemical Industry
Stereocomplexed polylactides (Neo‐PLA) as high‐performance bio‐based polymers: their formation, properties, and application
Authors: Fukushima Kazuki , Kimura Yoshiharu 
Published: April 2006

AbstractPolymeric materials prepared from renewable natural resources are now being accepted as “bio‐based polymers”, because they are superior to the conventional petroleum‐based polymers in reducing the emission of carbon dioxide. Among them, poly(L‐lactide) (PLLA) prepared by fermentation and polymerization is paid an immediate attention. Although PLLA exhibits a broad range of physico‐chemical properties, its thermal and mechanical properties are somewhat poorer for use as ordinary structural materials. For improving these inferior properties, a stereocomplex form consisting of PLLA and its enantiomer poly(D‐lactide) (PDLA) has high potential because of showing high melting nature (230 °C). It can be formed by simple polymer blend of PLLA and PDLA or more easily with stereoblock polylactides (sb‐PLA) which are PLLA/PDLA block copolymers. These novel PLA polymers, named “Neo‐PLA”, can provide a wide range of properties that have never be attained with single PLLA. Neo‐PLA retains sustainability or bio‐based nature, because both monomers L‐ and D‐lactic acids are manufactured from starch by fermentation. Copyright © 2006 Society of Chemical Industry
Solid‐state linear viscoelastic properties of intercalated poly(L‐lactide)/organo‐modified montmorillonite hybrids
Authors: Nam Pham Hoai , Kaneko Masahiro , Ninomiya Naoya , Fujimori Atsuhiro , Masuko Toru 
Published: April 2006

AbstractHybrids of poly(L‐lactide)/organophilic clay (PLACHs) have been prepared by a melt‐compounding process using poly(L‐lactide) (PLLA) and different contents of surface‐treated montmorillonite modified with a dimethyl dioctadecyl ammonium salt. The dispersion structures of clay particles in PLACHs were investigated using wide‐angle X‐ray diffraction and transmission electron microscopy. The solid‐state linear viscoelastic properties for these PLACHs were examined as functions of temperature and frequency. The incorporation of organo‐modified silicate into PLLA matrix enhanced significantly both storage moduli (E′) and loss moduli (E″). The strong enhancement observed in dynamic moduli of PLACHs could be attributed to uniformly dispersed state of the clay particles with high aspect ratio (= length/thickness of clay) and the intercalation of the PLLA chains between silicate layers. Copyright © 2006 Society of Chemical Industry
Melt rheological properties of polypropylene–polyamide6 blends compatibilized with maleic anhydride‐grafted polypropylene
Authors: Shi Dean , Jiang Fengdan , Ke Zhou , Yin Jinghua , Li Robert Kwok‐Yiu 
Published: April 2006

AbstractThe melt rheological properties of binary uncompatibilized polypropylene–polyamide6 (PP–PA6) blends and ternary blends compatibilized with maleic anhydride‐grafted PP (PP–PP‐g‐MAH–PA6) were studied using a capillary rheometer. The experimental shear viscosities of blends were compared with those calculated from Utracki's relation. The deviation value δ between these two series of data was obtained. In binary PP–PA6 blends, when the compatibility between PP and PA6 was poor, the deformation recovery of dispersed PA6 particles played the dominant role during the capillary flow, the experimental values were smaller than those calculated, and δ was negative. The higher the dispersed phase content, the more deformed the droplets were and the lower the apparent shear viscosity. Also, the absolute value of δ increased with the dispersed phase composition. In ternary PP–PP‐g‐MAH–PA6 systems, when the compatibility between PP and PA6 was enhanced by PP‐g‐MAH, the elongation and break‐up of the dispersed particles played the dominant role, and the experimental values were higher than calculated. It was observed that the higher the dispersion of the PA6 phase, the higher the δ values of the ternary blends and the larger the positive deviation. Unlike uncompatibilized blends, under high shear stress with higher dispersed phase content, the PP‐g‐PA6 copolymer in compatibilized blends was pulled out from the interface and formed independent micelles in the matrix, which resulted in reduced total apparent shear viscosity. The δ value decreased with increasing shear stress. Copyright © 2006 Society of Chemical Industry
Plasma Hydrophilization Effect on Different Textile Structures
Authors: Hossain Mokbul M. , Herrmann Axel S. , Hegemann Dirk 
Published: April 2006

AbstractSummary: The degree of plasma‐induced hydrophilization and the stability of the treatment are closely linked to the textile structure and the weave construction. This study investigates the plasma activation of polyester (PES) fabric structures to improve their wettability, as well as the aging effects. The hydrophilic modification is carried out by low pressure plasma treatments using oxygen containing gaseous mixtures (Ar/O2 and He/O2), and it is characterized by calculating contact angles (static and advancing) from capillary rise tests with water. In all cases, the wettability of plasma‐treated PES fabrics is improved significantly due to the formation of polar groups on the surface. In particular, the hydrophilicity of looser structured fabrics is improved remarkably as compared to tightly woven fabrics. Furthermore, the capillary phenomenon in fibrous assemblies is also described in this study.SEM image of a tightly woven fabric and the schematic representation of the liquid flow within a plasma‐hydrophilized fabric by capillary forces.magnified imageSEM image of a tightly woven fabric and the schematic representation of the liquid flow within a plasma‐hydrophilized fabric by capillary forces.
Non‐Thermal Plasma and TiO2‐Assisted n‐Heptane Decomposition
Authors: Pekárek Stanislav , Pospíšil Milan , Krýsa Josef 
Published: April 2006

AbstractSummary: We studied the decomposition of n‐heptane by DC hollow‐needle‐to‐mesh electrical discharge with or without a TiO2 photocatalyst. The discharge was enhanced by flowing air or a mixture of air with n‐heptane through the needle. The experiments with photocatalyst were performed with a TiO2‐coated stainless steel mesh and with a mesh covered with TiO2 globules. In each of these cases, the efficiency of n‐heptane decomposition increases with increasing energy density. A maximum decomposition efficiency of 50.4% was obtained for the discharge with a mesh covered with TiO2 globules for an energy density of 350 kJ · m−3 at a relative humidity of the mixture of 27%. For a given energy density, the decomposition efficiency is largest for the mesh covered with TiO2 globules. In this case, the humidity improves the decomposition efficiency.Effect of humidity on the efficiency of n‐heptane decomposition for the DC discharge using a mesh covered with TiO2 globules.magnified imageEffect of humidity on the efficiency of n‐heptane decomposition for the DC discharge using a mesh covered with TiO2 globules.
Acaricidal activities of paeonol and benzoic acid from Paeonia suffruticosa root bark and monoterpenoids against Tyrophagus putrescentiae (Acari: Acaridae)
Authors: Tak Jun‐Hyung , Kim Hyun‐Kyung , Lee Seung‐Hwan , Ahn Young‐Joon 
Published: April 2006

AbstractThe acaricidal activities of paeonol (2′‐hydroxy‐4′‐methoxyacetophenone) and benzoic acid identified in the root bark of tree peony, Paeonia suffruticosa Andrews, against copra mite, Tyrophagus putrescentiae (Schrank), adults were examined using direct contact and vapour phase toxicity bioassays and compared with those of cinnamyl acetate, cinnamyl alcohol and 37 monoterpenoids as well as the acaricides benzyl benzoate, dibutyl phthalate and N,N‐diethyl‐m‐toluamide (DEET). Based on LD50 values in fabric piece contact toxicity bioassays, the acaricidal activities of benzoic acid (4.80 µg cm−2) and paeonol (5.29 µg cm−2) were comparable to that of benzyl benzoate (4.46 µg cm−2) but more pronounced than those of DEET (30.03 µg cm−2) and dibutyl phthalate (25.23 µg cm−2). In vapour phase toxicity bioassays, paeonol and benzoic acid were much more effective in closed containers than in open ones, indicating that the effects of these compounds were largely due to action in the vapour phase. As judged by 24 h LD50 values, (1S)‐(−)‐verbenone (7.42 mg per disc) was the most toxic fumigant, followed by (1S)‐(−)‐camphor, (S)‐(+)‐carvone, (R)‐(−)‐linalool and (±)‐camphor (10.45–18.18 mg). Potent fumigant toxicity was also observed with paeonol, (2S,5R)‐(−)‐menthone, (±)‐citronellal, benzoic acid, (1S,4R)‐(−)‐α‐thujone and (R)‐(+)‐pulegone (25.10–34.63 mg). Neither benzyl benzoate, DEET nor dibutyl phthalate caused fumigant toxicity. Paeonia root bark‐derived materials, particularly paeonol and benzoic acid, as well as the monoterpenoids described, merit further study as potential acaricides or as leads for the control of T. putrescentiae. Copyright © 2006 Society of Chemical Industry