bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression and activity of C/EBPβ and δ are upregulated by dexamethasone in skeletal muscle
Authors: Yang Hongmei , Mammen Joshua , Wei Wei , Menconi Michael , Evenson Amy , Fareed Moin , Petkova Victoria , Hasselgren Per‐Olof
Published: January 2005

The influence of glucocorticoids on the expression and activity of the transcription factors CCAAT/enhancer binding protein (C/EBP)β and δ in skeletal muscle was examined by treating rats or cultured L6 myotubes with dexamethasone. Treatment of rats with 10 mg/kg of dexamethasone resulted in increased C/EBPβ and δ DNA binding activity in the extensor digitorum longus muscle as determined by electrophoretic mobility shift assay (EMSA) and supershift analysis. A similar response was noticed in dexamethasone‐treated myotubes. In other experiments, myocytes were transfected with a plasmid containing a promoter construct consisting of multiple C/EBP binding elements upstream of a luciferase reporter gene. Treatment of these cells with dexamethasone resulted in a fourfold increase in luciferase activity, suggesting that glucocorticoids increase C/EBP‐dependent gene activation in muscle cells. In addition, dexamethasone upregulated the protein and gene expression of C/EBPβ and δ in the myotubes in a time‐ and dose‐dependent fashion as determined by Western blotting and real‐time PCR, respectively. The results suggest that glucocorticoids increase C/EBPβ and δ activity and expression through a direct effect in skeletal muscle. © 2005 Wiley‐Liss, Inc.
Investigation of the operation time dependence of the yield of ammonia conversion to nitrogen(II) oxide by platinum catalyst sets
Authors: Kozub Paul A , Trusov Nikolai V , Gryn Grigorii I , Prezhdo Victor V
Published: January 2005

The origins of changes in the catalytic activity of platinum catalysts in the ammonia oxidation process are studied. A general mathematical model for the dependence of the catalyst activity on the operation time of a single platinum gauze is proposed. Simplified expressions for the catalytic activity of two basic types of catalyst sets are obtained. Optimization of the catalyst operation mode is investigated and an optimal mode is selected based on the industrial data.

© 2001 Society of Chemical Industry
Oxidative polymerization and partial dechlorination of 2,4,6‐trichlorophenol by a mixture of peroxidase isozymes from Vaccinium myrtillus
Authors: Stazi Silvia Rita , Fevereiro Pedro , Sermanni Giovanni Giovannozzi , Barros Raquel Aires
Published: January 2005

Plant peroxidases (EC 1.11.1.7) catalyze the oxidation of phenolic pollutants in the presence of hydrogen peroxide. In the present study, extracellular peroxidases from Vaccinium myrtillus cell suspension cultures (VMP) were evaluated for their ability to polymerize 2,4,6‐trichlorophenol (TCP), a ubiquitous environmental contaminant. The effect of pH, temperature, reaction time, enzyme amount and initial pollutant concentration on the treatment efficiency was investigated in order to optimize the reaction conditions for TCP removal. An appreciable removal efficiency and a partial dehalogenation of TCP was observed over a wide range of initial pollutant concentrations (0.1–20 mmol dm−3) and reaction conditions suggesting that VMP could be useful for potential decontamination applications. The use of polyethylene glycol in the reaction mixture allowed a reduction of the catalyst requirements needed to obtain well defined extents of TCP removal.

© 2001 Society of Chemical Industry
Cyclohexene hydrogenation using Group VIII metal complexes as catalysts in heterogeneous and homogeneous conditions
Authors: Quiroga M E , Cagnola E A , Liprandi D A , L'Argentière P C
Published: January 2005

The stability and catalytic behaviour of a ruthenium complex with chloride and tridecylamine as ligands were studied. The hydrogenation of cyclohexene carried out in mild conditions, both in homogeneous and heterogeneous conditions, was used as a test reaction. FTIR and XPS results show that the active species is the complex itself, which is stable under the reaction conditions. XPS determination shows that the ruthenium complex is tetra‐coordinated, suggesting that its formula is [RuCl2(NH2(CH2)12CH3)2]. This ruthenium complex supported on γ‐Al2O3is more active and sulfur‐resistant than the same complex unsupported and even more than a nickel complex with the above mentioned ligands. The Ru complex, supported or not, is also more active and sulfur‐resistant than a conventional Ru/γ‐Al2O3catalyst evaluated in the same operational conditions.

© 2001 Society of Chemical Industry
Biotransformation of (+)‐ and (−)‐bornyl acetate using the plant parasitic fungus Glomerella cingulata as a biocatalyst
Authors: Miyazawa Mitsuo , Miyasato Yoshiki
Published: January 2005

The microbial transformations of (+)‐ and (−)‐bornyl acetate were investigated using the plant parasitic fungus, Glomerella cingulata. As a result, (+)‐ and (−)‐bornyl acetate were converted to (+)‐ and (−)‐5‐exo‐hydroxybornyl acetate, (+)‐ and (−)‐5‐oxobornyl acetate and (+)‐ and (−)‐borneol respectively. The structures of the metabolic products were determined by spectroscopic data.

© 2001 Society of Chemical Industry
Lactic acid recovery from fermentation broth using one‐stage electrodialysis
Authors: Kim Yang Hoon , Moon Seung‐Hyeon
Published: January 2005

One‐stage electrodialysis (ED) for lactic acid recovery with two‐ and three‐compartment water‐splitting ED (WSED) was investigated using various ion‐exchange membranes in order to overcome the inefficiency of two‐stage ED, which consists of desalting ED for recovery and partial purification and subsequent WSED for acidification. The two‐compartment WSED had a low current efficiency and high energy consumption in spite of a simple stack configuration. A three‐compartment WSED successfully converted sodium lactate in the fermentation broth into lactic acid and sodium hydroxide with average yields of 96% and 93%, respectively. In relation to lactic acid purification, of the membranes tested in this study, the highest glucose rejection, 98.3%, was achieved using a PC 100D membrane. The CMS membrane rejected magnesium and calcium at levels as high as 81.7% and 78.5%, respectively. We concluded that the three‐compartment WSED with properly chosen membranes, enabled lactic acid to be recovered directly from the fermentation broth.

© 2001 Society of Chemical Industry
Mathematical model for ethanol production from mixed sugars by Pichia stipitis
Authors: Nakamura Yoshitoshi , Sawada Tatsuro , Inoue Eiichi
Published: January 2005

A mathematical model for estimating the dynamic behavior of ethanol production from mixed sugars such as glucose and xylose is presented. This model was constructed by introducing the term for ethanol production into the diauxic growth model proposed previously by the authors. It was assumed that the first substrate, glucose, is metabolized by a constitutive enzyme and the second substrate, xylose, is utilized by an inducible enzyme. The synthesis of the inducible enzyme is controlled by the catabolite repression caused by glucose and with the induction caused by xylose as an inducer, and the xylose is then converted into cell mass and ethanol by the inducible enzyme. The parameters of the model were estimated from the experimental data in the medium containing glucose and xylose, singly or in combination in a batch culture. The application of the model was examined for experiments in both batch and continuous culture, with glucose and xylose as carbon sources. The calculated values, according to the model, corresponded satisfactorily with experimental data, such as cell growth, substrate consumption, and ethanol production, especially in the estimation of the lag times between the first log phase and the second log phase in cell growth and ethanol production.

© 2001 Society of Chemical Industry
Batch and continuous studies on treatment of pulp mill wastewater by Aeromonas formicans
Authors: Gupta V K , Minocha A K , Jain Neeraj
Published: January 2005

Batch and continuous studies have been conducted on the treatment of black liquor from a kraft pulp and paper mill by a bacterial strain, Aeromonas formicans. The results of batch studies revealed that the strain was able to remove 71% and 78% of COD and lignin respectively, while the colour removal efficiency was around 86% in 10 days of retention time. The analysis of lignin degradation products by gas chromatography after 20 days of incubation revealed the formation of some phenolic acids, which were responsible for the decrease in pH during batch studies. The removal efficiencies of COD, colour and lignin obtained in continuous reactor studies were 73, 88 and 77% respectively for an 8 day detention period and these efficiencies were almost the same as obtained in batch studies.

© 2001 Society of Chemical Industry
Simultaneous organic carbon and nitrogen removal in an SBR controlled at low dissolved oxygen concentration
Authors: Dangcong Peng , Bernet Nicolas , Delgenes Jean‐Phillipe , Moletta Rene
Published: January 2005

Simultaneous organic carbon and nitrogen removal was studied in a sequencing batch reactor (SBR) fed with synthetic municipal wastewater and controlled at a low dissolved oxygen (DO) level (0.8 mg dm−3). Experimental results over a long time (120 days) showed that the reactor achieved high treatment capacities (organic and nitrogen loading rates reached as high as 2.4 kg COD m−3 d−1 and 0.24 kg NH3‐N m3 d−1) and efficiencies (COD, NH3‐N and total nitrogen removal efficiencies were 95%, 99% and 75%). No filamentous bacteria were found in the sludge even though the reactor had been seeded with filamentous bulking sludge. Instead, granular sludge, which possessed high activity and good settleability, was formed. Furthermore, the sludge production rate under low DO was less than that under high DO. Significant benefits, such as low investment and less operating cost, will be obtained from the new process.

© 2001 Society of Chemical Industry
The effect of an enzymatic pretreatment on the hydrolysis and size reduction of fat particles in slaughterhouse wastewater
Authors: Masse L , Kennedy K J , Chou S P
Published: January 2005

The effect of an enzymatic pretreatment, Pancreatic Lipase 250 (PL‐250), on the hydrolysis and size reduction of fat particles in slaughterhouse wastewater was characterised for enzyme doses ranging from 125 to 1000 mg dm−3 and initial particle sizes (Din) varying between 53 and 383 µm. Treatment with PL‐250 significantly reduced the size of pork fat particles in slaughterhouse wastewater. Particle size reduction increased with Din, possibly due to the more filamentous and plate‐like configuration of the larger fat particles, which could be easily broken at weak points. The smaller particles were observed to be denser and more spherical. Size reduction also increased with enzyme concentration, but the benefit of adding more enzyme diminished greatly as enzyme dose was increased. The maximum long‐chain fatty acid (LCFA) concentration in filtered samples was detected after 4–7 h of treatment and ranged from 8.2 to 34.9 mg dm−3. The linear rate of LCFA released in solution during enzymatic pretreatment ranged from 39.4 to 169.9 mg dm−3 d−1, and increased with enzyme concentration up to 500 mg dm−3. At a PL‐250 concentration of 1000 mg dm−3, the LCFA release rate decreased, maybe due to excessive layering of adsorbed enzyme on the fat particles or increased degradation of released LCFAs. The pretreatment appeared to be more efficient with beef than pork fat particles. However, the effect of an enzymatic pretreatment on a downstream anaerobic treatment of slaughterhouse wastewater containing fat particles remains to be tested.

© 2001 Society of Chemical Industry
Totally chlorine‐free bleaching of Acetosolv pulps: a clean approach to dissolving pulp manufacture
Authors: Abad Severino , Santos Valentín , Parajó Juan Carlos
Published: January 2005

Eucalyptus globulus wood samples were delignified in media containing concentrated acetic acid, water and hydrochloric acid (Acetosolv process) under optimized conditions, and the pulps were subjected to totally chlorine‐free (TCF) bleaching. Alkaline extractions, oxygen delignification, ozone treatment, enzymatic xylan removal and hydrogen peroxide oxidation in alkaline media were investigated as individual steps in selected bleaching sequences. Under the best conditions, fully bleached pulps with favourable characteristics for dissolving pulp manufacture were obtained.

© 2001 Society of Chemical Industry
Pilot plant biosorption in an integrated contact–settling system: application to Cu(II) removal by anaerobically digested sludge
Authors: Artola Adriana , Martin Maria J , Balaguer MaDolors , Rigola Miquel
Published: January 2005

Surplus biological sludge can be used as a low‐cost adsorbent in the removal of heavy metal from wastewater. A three‐zone contact–settling pilot plant was designed and operated to maintain continuous sludge–metal solution contact and subsequent separation of solid–liquid phases, all in the same vessel. Mild agitation was used to ensure good contact between Cu(II) and sludge without impairing solid–liquid separation. Heavy metal removal efficiency was largely unaffected by an increase in the Cu/sludge feed ratio as long as metal binding sites in the sludge remained unsaturated. Maximum metal uptake (75 mg Cu(II) g−1 of total solids in the sludge) was found for Cu/sludge feed ratios ≥ 90 mg Cu(II) g−1 of total solids. Pilot plant metal sorption uptake at different operational conditions correlated well with the calculated values from batch equilibrium adsorption isotherms. The amount of Cu(II) adsorbed on sludge influenced the degree of clarification due to the flocculating effect of Cu(II). Under operational conditions, a high degree of heavy metal removal and efficient clarification were achieved. Pilot plant operation at a Cu/sludge feed ratio around 90 mg Cu(II) g−1 of total solids allowed efficient use of the biosorbent and high heavy metal removal efficiency in addition to a good quality metal‐free effluent in terms of low total suspended solids content.

© 2001 Society of Chemical Industry
Ammonia‐functionalized particulate poly(glycidyl methacrylate‐co‐ethylene dimethacrylate)‐based polymers as stationary phase for protein retention
Authors: Paredes B , Suárez E , Rendueles M , Villa‐García M A , Díaz J M
Published: January 2005

A poly(glycidyl methacrylate‐co‐ethylene dimethacrylate) polymeric matrix was synthesized, amino‐functionalized and packed to be tested for protein retention and separation. Functionalization was carried out by reacting the epoxy groups with 30% ammonia solution to provide amino groups for anion exchange with proteins. Physical characterization of the particulate material showed that the functionalized polymer is macroporous and exhibits a unimodal pore size distribution. The resin presents good thermal stability. Chromatographic characterization using bovine serum albumin (BSA) and α‐lactalbumin as model proteins showed good retention properties for the amino‐functionalized matrix. The values obtained for the equilibrium constant (K) were around 3 for BSA, both in batch reactor and column‐packed operation mode. The K values for α‐lactalbumin were even higher, 8.01 and 4.65 for the batch and column‐packed experiments, respectively. Finally, axial dispersion coefficients were obtained, with a constant value of 0.0141 cm2s−1 for BSA. Higher values were obtained for α‐lactalbumin, but in this case the axial dispersion coefficient was not constant and its values were dependent on the flows used.

© 2001 Society of Chemical Industry
Effects on the removal of Pb2+ from aqueous solution by crab shell
Authors: Kim Dong Seog , Park Byoung Yoon
Published: January 2005

The effects of temperature, pH, chitin and chitosan on Pb2+ removal by crab shell were investigated. Pb2+ removal by crab shell was greater than that of chitin and chitosan, indicating that chitin did not contribute to Pb2+ removal by crab shell. The quantity and rate of Pb2+ removal increased as the pH value increased. The rate of Pb2+ removal increased with increased temperature, but the maximum amount of Pb2+ removal was constant irrespective of temperature. Metal ions (K+, Na+, Mg2+, Ca2+) were released from crab shell concomitant with Pb2+ removal by ion exchange. The amount of Ca2+ released was greater than any for other metal ions in both Pb2+ and Pb2+‐free solutions. The amount of Ca2+ released in Pb2+ solution was greater than that in Pb2+‐free solution, whereas CO32− release in Pb2+ solution was less than in Pb2+‐free solution. Pb2+ removal was mainly a consequence of dissolution of CaCO3(s) with consequence precipitation of Pb3(CO3)2(OH)2(s) and PbCO3(s). Pb2+ accelerated the dissolution of CaCO3(s) by ion exchange and the precipitation occurred both at the surface and in the inner part of the crab shell.

© 2001 Society of Chemical Industry
Preparation of no‐carrier‐added [124I]A14‐iodoinsulin as a radiotracer for positron emission tomography
Authors: Glaser Matthias , Brown David J. , Law Marilyn P. , Iozzo Patricia , Waters Stephen L. , Poole Keith , Knickmeier Markus , Camici Paolo G. , Pike Victor W.
Published: January 2005

A14‐Iodoinsulin is a close biochemical and pharmacological mimic of insulin. Human insulin was labelled in its A chain tyrosine‐14 residue by direct iodination with the positron‐emitter iodine‐124 (β+=25.6%; t1/2=4.15 days) to provide a radiotracer for imaging with positron emission tomography (PET). Several reagents were compared for conversion of cyclotron‐produced [124I]iodide into a reactive species for the labelling reaction. Radiochemical yields from the use of Iodo‐Gen®, Chloramine‐T, N‐bromosuccinimide or lactoperoxidase–hydrogen peroxide were similar [35% (n=1), 33±9% (n=10), 32±11% (n=25) or 33% (n=2), respectively]. [124I]A14‐Iodoinsulin was separated from unreacted insulin and radioactive by‐products by tandem reverse phase HPLC and rapidly formulated for intravenous injection by adsorption on a Sep‐Pak tC18‐Plus® cartridge, followed by elution with 10 mM hydrochloric acid–ethanol (1:1 v/v, 1 ml). This radiotracer can now be obtained in useful radioactivities at high effective specific radioactivity and is now being applied to PET studies of its biodistribution in living subjects. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis of 14C‐labeled E4010
Authors: Watanabe N. , Tokumura T. , Nakamura T.
Published: January 2005

14C‐Labeled E4010, [4‐(3‐chloro‐4‐methoxybenzyl)amino‐1‐(4‐hydroxy) ‐piperidino]‐6‐[4‐14C]phthalazinecarbonitrile monohydrochloride was synthesized for drug metabolism and pharmacokinetic studies using [1‐chloro‐4‐(3‐chloro‐4‐methoxybenzyl)amino]‐6‐[4‐14C]phthalazinecarbonitrile as the starting material. The radiochemical yield was 33.4%. The specific radioactivity and radiochemical purity, as determined by radio‐HPLC and LSC, were 4.77 MBq/mg and 99.8%, respectively. Copyright © 2001 John Wiley & Sons, Ltd.
Microbial synthesis of a deuterium‐labelled metabolite of an NK1 receptor antagonist, TAK‐637
Authors: Tarui Naoki , Ikeura Yoshinori , Natsugari Hideaki , Nakahama Kazuo
Published: January 2005

Microbial conversion of deuterium‐labelled TAK‐637 ((aR,9S)‐[10,10,11, 11‐2H4]‐7‐[3,5‐bis(trifluoromethyl)benzyl]‐8,9,10,11‐tetrahydro‐9‐methyl‐5‐(4‐methylphenyl)‐7H‐[1,4]diazocino[2,1‐g][1,7]naphthyridine‐6,13‐dione, 1) was carried out using Streptomyces subrutilus IFO13388 to give a deuterium‐labelled hydroxylated TAK‐637 ((aR,9S)‐ [10,10,11,11‐2H4]‐7‐[3,5‐bis(trifluoromethyl)benzyl]‐8,9,10,11‐tetrahydro‐9‐methyl‐5‐(4‐hydroxymethylphenyl)‐7H‐[1,4]diazocino[2,1‐g][1,7]naphthyridine‐6,13‐dione, 2) for use as an internal standard in LC‐MS studies. Copyright © 2001 John Wiley & Sons, Ltd.
Structural characterization of fatty acids cationized with copper by electrospray ionization mass spectrometry under low‐energy collision‐induced dissociation
Authors: Afonso Carlos , Riu Anne , Xu Ying , Fournier Françoise , Tabet Jean‐Claude
Published: January 2005

Fatty acids have for many years been characterized by mass spectrometry using electron ionization after chemical derivatization. When fatty acids are ionized using desorption/ionization methods such as electrospray ionization or fast atom bombardment, structural information is usually obtained through high‐energy collision‐induced dissociation (CID) using sector instruments. It has been shown that copper displays very interesting properties in the gas phase during CID. In this study, the reactivity of saturated and unsaturated fatty acid–copper [M − H + CuII]+ complex and the role of the copper ion in promoting fragmentations were investigated under low‐energy collisional activation conditions. The decomposition of these species in an ion trap instrument led to diagnostic ion series that reflect CC bond cleavage, which involves CuII reduction followed by the release of an alkyl radical. It was demonstrated that in this way the localization of one or two homoconjugated double bonds is possible using low‐energy CID. Moreover, the distinction of cis and trans isomers is possible through characteristic product ions related to a specific loss of CO2. When these experiments are repeated using a triple‐quadrupole instrument with argon as collision gas, a different behavior is observed as in this case, in addition to the product ion distributions observed in the ion trap, other distributions are observed that reflect the influence of the different kinetic shifts and the occurrence of consecutive decompositions. Different examples are presented with various saturated and unsaturated fatty acid chains. Mechanisms are proposed in order to rationalize the experimental observations. Copyright © 2005 John Wiley & Sons, Ltd.
Characterization of flavonoids by aluminum complexation and collisionally activated dissociation
Authors: Zhang Junmei , Wang Junmei , Brodbelt Jennifer S.
Published: January 2005

Aluminum complexes of the type [AlIII (flavonoid −H)2]+ are generated by electrospray ionization in order to allow differentiation of isomeric flavonoids by tandem mass spectrometry. The dominant species observed from the aluminum complexation reaction has a 1 : 2 aluminum(III) : flavonoid stoichiometry. Differentiation of 18 flavonoids constituting seven isomeric series was achieved based on the collisionally activated dissociation patterns of the aluminum complexes. Characteristic fragmentation pathways allow identification of the site of glycosylation, the type of saccharide (rutinose versus neohesperidose) and the type of bond between the C‐2 and C‐3 atoms (thus distinguishing flavanones from flavonols and flavones). Two stable coordination geometries of the aluminum complex of apigenin were identified. The non‐planar structure with a plane‐angle of nearly 90° is 25.3 kcal mol−1 more favorable than the planar structure. The conformations of the complexes, which involve multiple interactions between the aglycone and disaccharide portions of the flavonoid with the metal ion, are significantly different for the isomeric flavonoids. Copyright © 2005 John Wiley & Sons, Ltd.
Determination of the glycosylation site in flavonoid mono‐O‐glycosides by collision‐induced dissociation of electrospray‐generated deprotonated and sodiated molecules
Authors: Cuyckens Filip , Claeys Magda
Published: January 2005

The influence of the glycosylation site on the fragmentation behavior of 18 flavonoid glycoside standards was studied using positive and negative electrospray ionization mass spectrometry in combination with collision‐induced dissociation and tandem mass spectrometry. The glycosylation position is shown to affect the relative abundance of the radical aglycone ions that can be observed in the [M − H]− collision‐induced dissociation spectra. In particular, the radical aglycone ions are very abundant for deprotonated flavonol 3‐O‐glycosides. Collisional activation of the radical aglycone ions produced from positional isomers revealed minor differences: m, nB0− product ions are pronounced for 7‐O‐glycosides, whereas m, nA0− product ions are relatively more abundant for 4′‐O‐glycosides. In addition, the ratio between the radical aglycone and the regular aglycone ions in the [M + Na]+ high‐energy collision‐induced dissociation spectra gives an indication about the glycosylation site. This ion ratio allows the differentiation between flavonoid 3‐O‐ and 7‐O‐glycosides or can be useful in the comparison of unknown compounds with standards. Unambiguous differentiation between O‐glycosylation at the common positions of flavonoid O‐glycosides, i.e. the 3‐, 4′‐ and 7‐positions, is achieved by collisional activation of sodiated molecules at high collision energy. The presence of a B‐ring product ion containing the sugar residue indicates 4′‐O‐glycosylation, whereas the loss of the B‐ring part from the aglycone product ion is characteristic of 3‐O‐glycosylation and the loss of the B‐ring part from both the [M + Na]+ precursor ion and the aglycone product ion points to 7‐O‐glycosylation. Copyright © 2005 John Wiley & Sons, Ltd.
Exogenous Bcl‐xl fusion protein spares neurons after spinal cord injury
Authors: Nesic‐Taylor O. , Cittelly D. , Ye Z. , Xu G.Y. , Unabia G. , Lee J.C. , Svrakic N.M. , Liu X.H. , Youle R.J. , Wood T.G. , McAdoo D. , Westlund K.N. , Hulsebosch C.E. , Perez‐Polo J.R.
Published: January 2005

Spinal cord injury (SCI) induces neuronal death, including apoptosis, which is completed within 24 hr at and around the impact site. We identified early proapoptotic transcriptional changes, including upregulation of proapoptotic Bax and downregulation of antiapoptotic Bcl‐xL, Bcl‐2, and Bcl‐w, using Affymetrix DNA microarrays. Because Bcl‐xL is the most robustly expressed antiapoptotic Bcl‐2 molecule in adult central nervous system, we decided to characterize better the effect of SCI on Bcl‐xL expression. We found Bcl‐xL expressed robustly throughout uninjured spinal cord in both neurons and glia cells. We also found Bcl‐xL localized in different cellular compartments: cytoplasmic, mitochondrial, and nuclear. Bcl‐xL protein levels decreased in the cytoplasm and mitochondria 2 hr after SCI and persisted for 24 hr. To test the contribution of proapoptotic decreases in Bcl‐xL to neuronal death, we augmented endogenous Bcl‐xL levels by administering Bcl‐xL fusion protein (Bcl‐xL FP) into injured spinal cords. Bcl‐xL FP significantly increased neuronal survival, suggesting that SCI‐induced changes in Bcl‐xL contribute considerably to neuronal death. Because Bcl‐xL FP increases survival of dorsal horn neurons and ventral horn motoneurons, it could become clinically relevant in preserving sensory and motor functions after SCI. © 2005 Wiley‐Liss, Inc.
Generation of hydrogen peroxide during brief oxygen‐glucose deprivation induces preconditioning neuronal protection in primary cultured neurons
Authors: Furuichi Takamitsu , Liu Wenlan , Shi Honglian , Miyake Minoru , Liu Ke Jian
Published: January 2005

Although reactive oxygen species (ROS) have been implicated in ischemic preconditioning (IPC)‐induced neuronal protection, several key questions concerning ROS remain to be elucidated. The purpose of this study is to obtain direct evidence for the formation of specific ROS species generated by IPC, and to determine the specific species that is responsible for the observed neuronal protection. Primary cultured cortex neurons from rat embryos were preconditioned with 10 min of oxygen‐glucose deprivation (OGD), which increased the intracellular levels of superoxide and hydrogen peroxide. This preconditioning markedly induced neuronal protection against 2‐hr OGD stimuli. Preconditioning with exogenous ROS by the administration of xanthine/xanthine oxidase (X/XO), or hydrogen peroxide was also found to induce IPC‐like neuronal protection. Administration of hydrogen peroxide scavengers, such as catalase, glutathione, or the thiol reductant N‐(2‐mercaptopriopionyl)‐glycine, all reduced the increase in the intracellular hydrogen peroxide levels, which effectively eliminated IPC‐ or exogenous ROS‐induced neuronal protection. In contrast, administration of the membrane‐permeable superoxide dismutase mimic Mn(III)tetrakis(1‐methyl‐4‐pyridyl)porphyrin pentachloride was able to block the increase of intracellular superoxide levels during IPC, but did not abolish either IPC‐ or exogenous X/XO preconditioning‐induced neuronal protection. These findings strongly suggest that IPC enhances the generation of superoxide, which is then converted to hydrogen peroxide, and that hydrogen peroxide is likely the main trigger involved in the mechanism of IPC‐induced neuronal protection. © 2005 Wiley‐Liss, Inc.
Excited states of four hemes in a c-type cytochrome subunit of the photosynthetic reaction center ofRhodopseudomonas viridis: SAC-CI calculations
Authors: OHKAWA K. , HADA M. , NAKATSUJI H.
Published: January 2005

The excited states of four hemes, c-552, c-554, c-556, and c-559, in a c-type cytochrome subunit of the photosynthetic reaction center (PSRC) of Rhodopseudomonas (Rps.) viridis were studied using the symmetry-adapted cluster (SAC)-configuration interaction (CI) method. c-552 has two imidazole ligands, while the other three hemes have imidazole and methionine ligands. The electronic states of these four hemes are affected significantly by both the ligands and protein and water environments. The ligand effect classifies the four hemes into two groups, while the environmental effect is unique in each heme. The HOMO–LUMO energy separation of c-552 is much smaller than those of the other hemes, and therefore, the low-lying excited states of c-552 are more stable than those of the other hemes. The low-lying excited states and their oscillator strengths of c-559 are significantly modified by the environment when compared with c-556 and c-554. Some observed UV peaks of the PSRC of Rps. viridis were found to have been assigned reasonably to the excited states of these four hemes in a previous report. The calculated linear dichroism angles also supported our assignment.
Bis-thallium(I) porphyrin complexes
Authors: LAI JAN-JI , KHADEMI SHAHRAM , MEYER EDGAR F. , CULLEN DAVID L. , SMITH KEVIN M.
Published: January 2005

Thallium(I) complexes of 2,3,7,8,12,13,17,18-octaethylporphyrin and 5,10,15,20-tetraphenylporphyrin are shown to have two thallium(I) ions per porphyrin ligand. Syntheses, spectroscopic characteristics (UV-vis, MS, NMR), chemistry, and an X-ray crystal structure of bis-thallium(I) porphyrins are presented.
In vitro and in vivo studies of new cationic Zn(II)-benzonaphthoporphyrazines as photosensitizers for PDT
Authors: PEEVA M. , SHOPOVA M. , MICHELSEN U. , WÖHRLE D. , PETROV G. , DIDDENS H.
Published: January 2005

Four recently synthesized cationic zinc(II)-benzonaphthaporphyrazines 1–4 were studied in vitro and in vivo for their photodynamic therapy (PDT) effectivity. The photophysical measurements showed that in solution and in Cremophor micelles all examined compounds exhibit very high absorption intensity in the spectral range between 680 to 750 nm. The fluorescence emission for 3 and 4 was very well expressed in different media, as well as in cell culture. The dark toxicity examinations on invasive human bladder carcinoma cell line EJ did not show any traces of toxicity. The investigations connected with the detection of their phototoxic capacity on the same cell line demonstrated very promising results especially with photosensitizers 3 and 4. The in vivo studies with these two compounds demonstrating high cell-phototoxic effect were carried out against Lewis lung carcinoma in mice after incorporation in Cremophor micelles. The excitation was done at the respective maximum absorption wavelength for each of the sensitizers at a fluence rate of 380 mW cm-2 and a fluence of 360 J cm-2. The phototherapeutic effect was evaluated through macroscopic observations (tumour growth delay) and by electron microscopy detection. According to these approaches the best effect (including tumour destroyment) was detected after PDT treatment with the cationic tribenzonaphthoporphyrazinato-zinc(II) 3. Typical features of random, but not of programmed, cell death necrosis were observed.
Intramolecular fluorescence quenching in porphyrin-bearing [2]catenates
Authors: HUNGERFORD GRAHAM , VAN DER AUWERAER MARK , AMABILINO DAVID B.
Published: January 2005

The fluorescence quenching of a Zn(II) porphyrin linked to Cu(I) catenates relative to a model compound without Cu(I) was attributed to energy transfer from the Zn(II) porphyrin to the metal-to-ligand charge transfer (MLCT) state of the Cu(I) (phenanthroline)2 center at the core of the molecules. The similarity of the fluorescence spectra and fluorescence decays of a Zn(II) porphyrin linked to an Au(III) porphyrin, a Zn(II) porphyrin or a benzoate moiety through the catenate framework suggested that no fluorescence quenching by electron transfer to the Au(III) porphyrin occurred and that the copper(I) (phenanthroline)2 center acts as an energy sink. The value of the critical distance for Förster type energy transfer, determined from spectral data is compatible with the observed rate constants for energy transfer and dimensions of the macrocycle. The multi-exponential nature of the fluorescence decay is attributed to the presence of different slowly interconverting conformations of the macrocycle to which the porphyrins are attached.
Unequivocal evidence about the presence of Fe(III) in μ-oxo-bis[tetrakis(t-butyl)phthalocyaninatoiron]
Authors: ERCOLANI CLAUDIO , MONACELLI FABRIZIO
Published: January 2005

μ-Oxo-bis[tetrakis(t-butyl)phthalocyaninatoiron] (1) reacts with L-ascorbic acid (LAA) in pyridine containing CH 2 Cl 2 under strictly anaerobic conditions to yield dehydroascorbic acid (DHA) and Pc t FeII ( py )2 (Pct = tetrakis (t-butyl)phthalocyaninato dianion). The reaction is quantitative with a 1:1 LAA/1 stoichiometric ratio. This result can be explained only if it is assumed that the μ-oxo complex 1 (reacting as the bispyridine adduct) is an iron(III) complex able to oxidise LAA to DHA quantitatively. Present findings definitively rule out the alternative iron(II) structure H 2[( Pc t Fe )2 O ] which has been assigned to compound 1 by other authors.
Physical and chemical studies related to the development of m-THPC (FOSCAN®) for the photodynamic therapy (PDT) of tumours
Authors: BONNETT RAYMOND , DJELAL BIRGUL D. , NGUYEN ANGELINA
Published: January 2005

Aggregation of 5,10,15,20-tetrakis(m-hydroxyphenyl)chlorin (m-THPC) is observed not to occur in methanol or in ethanol:polyethyleneglycol 300:water = 2:3:5 (v/v) in the concentration range of 0.46–73.4 × 10-5M and 0.92–29.4 × 10-5M , respectively. However, aggregation occurs for 4.59 × 10-5M solutions in methanol–water mixtures for compositions >50% water (v/v). The Soret band broadens and εmaxdecreases; λmaxshows a red shift, consistent with a J-type structure. Possible aggregate structures are considered based on the known hydrogen bonding patterns in crystalline solvates of the closely related 5,10,15,20-tetrakis(3,5-dihydroxyphenyl)porphyrin. Spectrophotometric titration of m-THPC in methanol–buffer mixtures gives apparent p Kavalues of p K3= 3.45 and p K4= 1.45. The phenolic groups have p Ka= 10.0. Comparisons are made with the corresponding porphyrin and with literature values on related systems. Singlet oxygen chemistry. The photobleaching of bilirubin is shown to be accelerated fivefold in the presence of a 0.05 mol proportion of m-THPC. The accelerated reaction is slowed down in the presence of 2,5-dimethylfuran and of β-carotene, providing further evidence by chemical reaction for the ability of m-THPC to photogenerate singlet oxygen. The relevance of these observations to clinical usage is discussed briefly.
Synthetic aspects of 2,2'-bisdipyrrins
Authors: BRÖRING MARTIN , GRIEBEL DRAGAN , HELL CHRISTIAN , PFISTER ANDREAS
Published: January 2005

The synthesis of open-chain, tetrapyrrolic 2,2'-bisdipyrrin ligands was investigated, starting from a variety of different pyrrolic and 2,2'-bipyrrolic precursors. Four important observations were made: (1) The solubility of 2,2'-bisdipyrrins can easily be tuned through the peripheral substituent pattern, allowing the aimed preparation of both well-soluble and hardly soluble tetrapyrroles. (2) meso-Arylsubstituted 2,2'-bisdipyrrins are easily available from respective p- and m-, but not o-functionalized dibenzoyl bipyrroles due to sterical effects. (3) Unsymmetric derivatives can be obtained by the stepwise acylation of 2,2'-bipyrroles and concomitant condensation reactions, using the new 5-benzoyl-3,3',4,4'-tetraethyl-2,2'-bipyrrole as the key intermediate. (4) meta-Nitrophenyl groups in the periphery of 2,2'-bisdipyrrins can be reduced to aminophenyl groups and further derivatized in analogy to a reaction cascade used in porphyrin chemistry, yielding superstructured 2,2'-bisdipyrrins. The synthetic schemes developed open the way for a large variety of tailor-made 2,2'-bisdipyrrin ligands.
A critical review of the glaciomarine model for Irish sea deglaciation: evidence from southern Britain, the Celtic shelf and adjacent continental slope
Authors: Scourse J. D. , Furze M. F. A.
Published: January 2005

In support of their ‘glaciomarine’ model for the deglaciation of the Irish Sea basin, Eyles and McCabe cited the occurrence of distal glaciomarine mud drapes onshore in the Isles of Scilly and North Devon, and of arctic beach‐face gravels and sands around the shores of the Celtic Sea. Glacial and sea‐level data from the southern part of the Irish Sea in the terminal zone of the ice stream and the adjacent continental slope are reviewed here to test this aspect of the model. The suggestion that the glacial sequences of both the Isles of Scilly and Fremington in North Devon are glaciomarine mud drapes is rejected. An actively calving tidewater margin only occurred early in the deglacial sequence close to the terminal zone in the south‐central Celtic Sea. Relative sea‐levels were lower, and therefore glacio‐isostatic depression less, than envisaged in the glaciomarine model. Geochronological, sedimentological and biostratigraphical data indicate that the raised beach sequences around the shores of the Celtic Sea and English Channel were deposited at, or during regression soon after, interglacial eustatic highstands. Evidence for ice‐rafting at a time of high relative sea‐levels is restricted to a phase(s) earlier than the Late Devensian. These data indicate that the raised beach sequences have no bearing on the style of Irish Sea deglaciation. Copyright © 2001 John Wiley & Sons, Ltd.
Sedimentary evidence for deforming bed conditions associated with a grounded Irish Sea glacier, southern Ireland
Authors: Cofaigh Colm Ó , Evans David J.A.
Published: January 2005

Along the south coast of Ireland, a shelly diamict facies, the Irish Sea Till, has been variously ascribed to subglacial deposition by a grounded Irish Sea glacier or to glacimarine sedimentation by suspension settling and iceberg rafting. Observations are presented here from five sites along the south coast to directly address this question. At these sites, sedimentary evidence is preserved for the onshore advance of a grounded Irish Sea glacier, which glacitectonically disturbed and eroded pre‐existing sediments and redeposited them as deformation till. Recession of this Irish Sea glacier resulted in the damming of ice‐marginal lakes in embayments along the south coast, into which glacilacustrine sedimentation then took place. These lake sediments were subsequently glacitectonised and reworked by overriding glacier ice of inland origin, which deposited deformation till on top of the succession. There is no evidence for deposition of the Irish Sea diamicts by glacimarine sedimentation at these sites. The widespread development of subglacial deforming bed conditions reflected the abundance of fine‐grained marine and lacustrine sediments available for subglacial erosion and reworking. Stratigraphical and chronological data suggest that the advance of a grounded Irish Sea glacier along the south coast occurred during the last glaciation, and this is regionally consistent with marine geological data from the Celtic Sea. These observations demonstrate extension of glacier ice far beyond its traditional limits in the Celtic Sea and on‐land in southern Ireland during the last glaciation, and remove the stratigraphical basis for chronological differentiation of surficial glacial drifts, and thus the Munsterian Glaciation, in southern Ireland. Copyright © 2001 John Wiley & Sons, Ltd.
Raman scattering of Nd0.9Ca0.1Ba2Cu3O7−δ with different oxygen contents
Authors: Zhao Yun , Xing Tang Ding , Zuo Jian , Xu Cunyi
Published: January 2005

A series of Nd0.9Ca0.1Ba2Cu3O7−δ samples with different oxygen contents were fabricated by the solid‐state reaction method and thermally treated under different conditions. The superconducting transition temperatures Tc were measured to be above liquid nitrogen temperature. The measurements of the thermopower S showed a monotonic decrease with increasing oxygen content. The Raman peak of the apical oxygen O(4) stretching vibration shifts to higher wavenumber, which also shows a monotonic increase in oxygen content. Two modes at 224 and 597 cm−1 are assigned to the disorder‐induced stretching vibrations of copper and oxygen atoms, respectively. They arise from symmetry breaking from short‐chain fragments and are not due to impurity phases. Copyright © 2001 John Wiley & Sons, Ltd.
Raman spectroscopy of potassium acetate‐intercalated kaolinites over the temperature range 25–300,°C
Authors: Frost Ray L. , Kristof Janos , Horváth Erzsébet , Kloprogge J. Theo
Published: January 2005

Raman spectra of the hydroxyl‐stretching region of potassium acetate‐intercalated kaolinite were obtained under an atmosphere of both air and nitrogen using a thermal stage over the temperature range 25–300 °C. At 25 °C, an additional band at 3606 cm−1 attributed to the inner surface hydroxyl hydrogen bonded to the acetate ion is observed with a concomitant loss of intensity in the bands attributed to the inner surface hydroxyls. Heating the intercalated complex to 50 °C results in two hydroxyl‐stretching wavenumbers at 3594 and 3604 cm−1. At 100 °C, the bands shift to 3600 and 3613 cm−1. At temperatures from 100 to 300 °C, bands are observed in similar positions. Upon cooling in air to 25 °C, the acetate‐bonded inner surface hydroxyl stretching wavenumber shifts back to 3606 cm−1. Upon heating the intercalated kaolinite to 300 °C under an atmosphere of nitrogen and upon cooling the acetate‐bonded inner surface hydroxyl stretching wavenumber is observed at 3601 cm−1. Upon cooling to 150 °C and subsequently to 25 °C, two bands are observed at 3611 and 3600 cm−1. Upon rehydration, the hydroxyl stretching wavenumber returns to 3606 cm−1. The changes in the Raman spectra of the hydroxyl‐stretching region during dehydration and rehydration are reversible. When the potassium acetate‐intercalated kaolinite is heated to 300 °C and cooled to 25 °C, the inner‐hydroxyl band is observed at 3630 cm−1. The shift in the wavenumber of the inner hydroxyl band is attributed to the insertion of the potassium ion in the ditrigonal cavity of the siloxane layer. Copyright © 2001 John Wiley & Sons, Ltd.
High‐technology firms' perceptions of their international competitiveness
Authors: Jones Marian V. , Crick Dave
Published: January 2005

This paper positions itself in the growing body of work on international entrepreneurship and investigates the perceptions of a small sample of high‐technology UK firms operating in overseas markets.

Some firms were found to employ a number of modes of market entry other than the exporting route prescribed by much of the existing literature and the focus of government trade assistance that is available.

Quantitative analysis is undertaken to establish that few statistical differences exist between two groups of firms — those involved only in exporting and those with activities incorporating multiple forms of market entry — in relation to their perceived performance and competitiveness in overseas markets.

In managing the changing circumstances of dealing with overseas markets, academics, policy makers and trainers should encourage managers to plan and balance resource constraints in accordance with the modes of market entry undertaken. Copyright © 2001 John Wiley & Sons, Ltd.
Can near‐infrared reflectance of green coffee be used to detect introgression in Coffea arabica cultivars?
Authors: Bertrand Benoît , Etienne Hervé , Lashermes Philippe , Guyot Bernard , Davrieux Fabrice
Published: January 2005

Most new coffee cultivars disseminated over the last 15 years are derived from the Timor Hybrid (Coffea arabica × C canephora). Introgression of genes from the C canephora genome has been estimated at between 9 and 29% of the genome. It has been shown that introgression can have a negative impact on the cup quality of cultivars derived from the Timor Hybrid. Consequently, coffee buyers or roasters may wish to assess whether the coffee they are purchasing comes from introgressed varieties. The possibility of distinguishing between non‐introgressed Arabicas and genotypes carrying chromosome fragments introgressed from C canephora was investigated (i) using some classical chemical compounds (caffeine, chlorogenic acids, trigonelline, fat and sucrose) and (ii) using a new approach based on spectra acquired by near‐infrared reflectance of green coffee. Near‐infrared spectra were obtained for 129 samples from two collections (Nicaragua and Costa Rica) of introgressed and non‐introgressed coffee trees. The spectral collections were treated by principal component and factorial discrimination. When the introgressed coffee trees were compared with the non‐introgressed trees using the chemical compounds, small but significant differences were found in caffeine, trigonelline and chlorogenic acid contents. However, the small variations in those compounds are not enough to detect introgression. The spectral collections treated by principal component and factorial discrimination made it possible to class from 92.30 to 94.87% of the analysed samples correctly, while the percentages of correctly classified samples in the verification file varied from 88.23 to 94.11%. The NIRS method appears to be an efficient method for determining whether a green coffee comes from an introgressed variety. Copyright © 2005 Society of Chemical Industry
Polyphenoloxidase (PPO) activity and osmotic dehydration in Granny Smith apple
Authors: Quiles Amparo , Hernando Isabel , Pérez‐Munuera Isabel , Larrea Virginia , Llorca Empar , Lluch M Ángeles
Published: January 2005

Osmotic dehydration (OD) permits the preservation of foods via a decrease in water content and an increase in solute concentration. Osmotically dehydrated fruits such as apple are suitable for the manufacture of desserts, cakes, salads, yoghurts, etc. Different microstructural and engineering aspects of OD are already known, but its effects on enzymatic activity are still unknown. This study analyses the activity of polyphenoloxidase (PPO) in fresh Granny Smith apples and the effect that OD by immersion in sucrose‐saturated syrup has on this activity. The low PPO activity found in the edible parenchyma of osmotically dehydrated apples is attributed to penetration by the osmotic agent and flooding of the intercellular spaces, which produces a low moisture content and a limited O2 concentration in the immediate environment of the enzyme. These results show that OD prevents enzyme–substrate interaction. Thus the low PPO activity would reduce browning of this type of product. Copyright © 2005 Society of Chemical Industry