bluuebunny/crossref_metadata_2025_split huggingface dataset:
Formaldehyde biodegradation and its inhibitory effect on nitrification
Authors: Eiroa Marta , Kennes Christian , Veiga María C 
Published: April 2004

AbstractThe simultaneous removal of formaldehyde and ammonium in aerobic cultures and the inhibitory effect of formaldehyde on ammonium oxidation were investigated. The influence of a co‐substrate, methanol, on formaldehyde biodegradation and on the nitrification process was also evaluated. Formaldehyde was completely removed at all concentrations tested (30–3890 mg dm−3) in assays with that compound as the single carbon source and in the presence of methanol as co‐substrate. An initial formaldehyde biodegradation rate of 4.6 g CH2O g−1 VSS d−1 was obtained for 2000 mg CH2O dm−3 as single carbon source compared with a rate of 7.3 g CH2O g−1 VSS d−1 when methanol was added. Formaldehyde was inhibitory to the nitrification process at initial concentrations higher than 350 mg dm−3. Increasing the initial formaldehyde concentration or adding a co‐substrate such as methanol resulted in a longer lag phase before ammonium oxidation and caused a decrease in the degree of nitrification. Nitrification was completely inhibited at initial formaldehyde concentrations higher than 1500 mg dm−3. Copyright © 2004 Society of Chemical Industry
Exploring process options to enhance metal dissolution in bioleaching of Indian Ocean nodules
Authors: Mukherjee Amitava , Raichur Ashok M , Modak Jayant M , Natarajan KA 
Published: April 2004

AbstractPolymetallic Indian Ocean nodules offer a lucrative resource for valuable strategic metals such as Cu, Co and Ni. A novel bioleaching process using cell‐free spent growth medium from a fully‐grown culture of a marine organism isolated from the nodules (Bacillus M1) dissolved about 45% Co, and 25% Cu and Ni at a the pH of 8.2 in 4 h. To enhance metal dissolution, different modifications in the bioleaching process, such as increasing the pH of the spent growth medium, carrying out leaching in multiple steps, and introducing organic reductant in the leach pulp, were investigated in this study. Increasing the initial pH of the spent growth medium to above 12 resulted in a 25–30% increase in dissolution of Cu, Co and Ni. The pKa value for the spent growth medium was observed to be in the range of 11.5–12.5. UV‐visible spectroscopy of the growth medium at pH values above 10.0 suggested a change in the structure of complexing phenolic substances present therein. A four‐step leaching process using the spent growth medium, each step lasting for about 4 h, was able to bring around 60% Cu and Ni and 85% Co in solution. About 85% Co, 90% Cu and 60% Ni were dissolved in two‐stage leaching, in which the bioleached residue was treated with the spent growth medium from Acidithiobacillus thiooxidans in the second cycle. The effects of concentration of starch (0.1–10%) as an organic reductant to the spent growth medium were also studied. The dissolution of Cu, Co and Ni stabilized at about 80–85% at a starch concentration of 3% and did not increase much thereafter. Copyright © 2004 Society of Chemical Industry
Kinetics of fluid–solid reaction with an insoluble product: zinc borate by the reaction of boric acid and zinc oxide
Authors: Shete Aparna V , Sawant Sudhir B , Pangarkar Vishwas G 
Published: April 2004

AbstractMixing parameters influencing the final particle size and conversion of zinc oxide were studied for the formation of zinc borate. Formation of zinc borate was via a fluid–solid reaction. The process was kinetically controlled above the minimum speed for particle suspension, Ns. The reaction kinetics was developed and the rate constant was estimated. Copyright © 2004 Society of Chemical Industry
Enhancement of biodegradability of industrial wastewaters by chemical oxidation pre‐treatment
Authors: Mantzavinos Dionissios , Psillakis Elefteria 
Published: April 2004

AbstractChemical oxidation technologies are often employed for the treatment of complex industrial effluents that are not amenable to conventional biological methods. The role of chemical oxidation depends on the treatment objectives and may vary from partial remediation to complete mineralization. In the case of partial treatment, chemical oxidation aims at the selective removal of the more bioresistant fractions and their conversion to readily biodegradable intermediates that can subsequently be treated biologically. Coupling chemical pre‐oxidation with biological post‐treatment is conceptually beneficial as it can lead to increased overall treatment efficiencies compared with the efficiency of each individual stage. This paper reviews recent developments and highlights some important aspects that need to be addressed when considering such integrated schemes. Copyright © 2004 Society of Chemical Industry
Characterisation of the glass fraction of a selection of European coal fly ashes
Authors: Henry J , Towler MR , Stanton KT , Querol X , Moreno N 
Published: April 2004

AbstractFly ash largely consists of the inorganic content of coal that remains after combustion. The crystalline phases present in fly ash may form upon cooling of a molten alumino‐silicate glass. This view is supported by the spherical shape of many fly ash particles, inferring that they have gone through a viscous fluid state. The amorphous content in fly ash is believed to dominate reactivity behaviour, under both alkaline and acid conditions, because glasses have a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass makes the bond breakage easier. It is the degradation behaviour under alkaline conditions, and the subsequent release of silica from the glass phase, that is important in the use of fly ash for conversion to zeolites and for pozzolanic applications in cement. This research comprehensively studies the composition, quantity and stability of the glass phase in a series of nine fly ashes sourced from Spanish and Italian power plants. The quantitative elemental composition of the glass phase in each fly ash was determined. Samples of the ashes then underwent a series of tests to determine the internal structure of the ash particles. Heat treatment of most of the ashes results in mullite crystallising from the glass phase; this is the crystalline phase that is predicated to form by both the relevant phase diagrams and also by NMR spectroscopy. In the ashes, mullite is present as a spherical shell, tracing the outline of the particle but in some specific cases the mullite skeleton is made up of coarse crystals reach also the internal parts of the particles. The morphology and density of the mullite crystals in these shells varies greatly. This work has supported the view that some crystalline phases present in fly ashes, such as mullite, form upon cooling of the amorphous glass melt as opposed to direct conversion from existing mineral phases in the coal during the combustion process. Copyright © 2004 Society of Chemical Industry
High resistance to aerial oxidation of an amorphous NiB/SiO2 catalyst: TP‐XRD, TPR and related investigations
Authors: Wang Yong‐Zhen , Li Xiang , Li He‐Xing , Wang Wei‐Jiang 
Published: April 2004

AbstractAn amorphous NiB/SiO2 catalyst, prepared by a reductive–impregnation method, was thoroughly studied as to its behavior in air and in benzene hydrogenation in a fixed‐bed reactor at atmospheric pressure. The results showed that the amorphous NiB/SiO2 catalyst possessed long life and excellent resistance to aerial oxidation. Even after calcination at 400 °C, TP‐XRD and TPR measurements revealed that the amorphous NiB/SiO2 catalyst was not oxidized, and could retain its activity in benzene hydrogenation. Copyright © 2004 Society of Chemical Industry
Development of an adenoviral vector system with adenovirus serotype 35 tropism; efficient transient gene transfer into primary malignant hematopoietic cells
Authors: Nilsson Marcus , Ljungberg Johan , Richter Johan , Kiefer Thomas , Magnusson Mattias , Lieber André , Widegren Bengt , Karlsson Stefan , Fan Xiaolong 
Published: April 2004

AbstractBackgroundA paucity of coxsackie adenovirus receptor (CAR) hampers the adenovirus serotype 5 (Ad5)‐based vector‐mediated gene transfer into malignant hematopoietic cells. Fiber‐retargeted adenoviral vectors with species B tropism can potentially bypass the CAR requirement and facilitate efficient gene transfer into malignant hematopoietic cells.MethodsFor feasible generation of fiber‐retargeted adenoviral vectors, we have modified the versatile AdEasy system with a chimeric fiber gene encoding the Ad5 fiber tail domain and Ad35 fiber shaft and knob domains. An Ad5‐based vector encoding the green fluorescent protein (GFP) gene under the control of the PGK promoter with Ad35 fiber receptor specificity was generated (Ad5F35‐GFP). The Ad5F35‐GFP vector‐mediated gene transfer efficiency was compared with a fiber non‐modified Ad5‐GFP vector, which also encodes the GFP gene under the control of the PGK promoter.ResultsWe demonstrated that a variety of Ad5‐refractory malignant myeloid and B lymphoid cell lines were highly permissive to the Ad5F35‐GFP vector infection. Importantly, primary chronic myeloid leukemic (CML) cells and chronic lymphocytic leukemia (CLL) B cells were superiorly transduced by the Ad5F35‐GFP vector at a multiplicity of infection (MOI) of 100 compared with the Ad5‐GFP vector.ConclusionsOur study will facilitate the generation of fiber‐retargeted adenoviral vectors and enable transient genetic manipulation of primary malignant hematopoietic cells. Copyright © 2004 John Wiley & Sons, Ltd.
Short‐term culture of myeloid leukemic cells allows efficient transduction by adenoviral vectors
Authors: Vereecque Rodolphe , Saudemont Aurore , Quesnel Bruno 
Published: April 2004

AbstractBackgroundEx vivo gene therapy of acute myeloid leukemia (AML) requires efficient transduction of leukemic cells. Recombinant adenovirus has been reported to be a poorly efficient vector in leukemic cells. We investigated leukemic cell culture as a possible method of improving the efficacy of this vector.MethodsLeukemic cell lines and primary cultured AML cells were incubated with adenoviral vectors carrying GFP, LacZ, or IL‐12 cDNA. Transduction efficiency was evaluated by measuring adenoviral genome copy number and transgene expression in leukemic cells. The expression of the coxsackie/adenovirus receptor (CAR), CD29, CD49e, and CD51/61 was measured, as was the effect of blocking integrin on adenoviral transduction.ResultsIncreasing the multiplicity of infection (MOI) to 300 plaque‐forming units per cell enhanced transduction of leukemic cell lines and to a lesser degree of AML cells. Analysis of adenoviral genome copy per cell showed only a partial correlation between gene transfer efficiency and transgene expression. Culture of AML cells for 3 days prior to adenoviral transduction increased both adenoviral copy number per cell and the percentage of transgene‐expressing cells. CD29, CD49e, and CD51/61 but not CAR expression increased in cultured AML cells between days 0 and 3 and integrin‐blocking experiments showed inhibition of transduction in two of four AML samples tested.ConclusionsEfficient ex vivo gene transfer in primary cultured AML cells can be achieved by short‐term culture of leukemic cells prior to gene transfer with adenoviral vectors at a high MOI. This effect appears to be at least partially mediated by enhanced integrin expression. Copyright © 2004 John Wiley & Sons, Ltd.
Lipid A components from Pseudomonas aeruginosa PAO1 (serotype O5) and mutant strains investigated by electrospray ionization ion‐trap mass spectrometry
Authors: Bedoux Gilles , Vallée‐Réhel Karine , Kooistra Oliver , Zähringer Ulrich , Haras Dominique 
Published: April 2004

AbstractThe lipid A components of the Pseudomonas aeruginosa strains PAO1 (wild‐type) and derived mutants PAO1 algC::tet and PAO1 PDO100 were isolated after mild acetic acid hydrolysis of LPS. Their structural heterogeneities were characterized using electrospray ionization (ESI) ion‐trap mass spectrometry (MS) with direct infusion in the negative ion mode without prior derivatization. The ESI‐mass spectra revealed monophosphorylated molecules corresponding to known tetra‐, penta‐ and hexaacylated structures of P. aeruginosa lipid A. The MS/MS fragmentation patterns allowed the location of fatty acyl chains on the disaccharide backbone of lipid A. In addition, a hexaacylated lipid A containing a hexadecanoyl chain was detected for the first time in strain P. aeruginosa PAO1. With multiple stages of fragmentation (MSn), the position of this hexadecanoyl chain O‐linked to the decanoyl chain at the C‐3′ position of the glucosamine backbone was determined. This sensitive method is suitable to reveal lipid A heterogeneity, i.e. the nature, number and distribution of acyl chains, without prior lipopolysaccharide purification. The lipid A from mutant strains were also characterized and significant differences were shown in the abundance of monophosphorylated lipid A components between the wild‐type and the mutant strains. Copyright © 2004 John Wiley & Sons, Ltd.
Structural analysis of lipid A from Escherichia coli O157:H7:K− using thin‐layer chromatography and ion‐trap mass spectrometry
Authors: Lee Chang‐Soo , Kim Yun‐Gon , Joo Hwang‐Soo , Kim Byung‐Gee 
Published: April 2004

AbstractRapid separation and structural identification of lipid A from Escherichia coli were performed using thin‐layer chromatography (TLC) and mass spectrometry (MS). After the resolved spot of the lipid A had been scraped from TLC plate, the sample was re‐extracted from the removed powder with chloroform–methanol (2 : 1, v/v) and analyzed by matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) and electrospray ionization (ESI) ion‐trap MS. For detailed structural characterization, multiple‐stage mass analysis (MS4) of the major species in ESI‐MS/MS provided important information about the series of fragment ions. The dominant fragment ions in each MS stage were produced from the loss of fatty acyl groups mainly driven by charge‐remote processes, and this information about the fragment ions can be used to deduce the composition or the position of the fatty acid substituent in the lipid A. In contrast, MALDI‐TOFMS indicated that fragmentation resulted from charge‐driven processes. Molecular mass profiling and fragmentation analysis provides essential information for clarifying the detailed structure of the lipid A from E. coli O157:H7:K−. Copyright © 2004 John Wiley & Sons, Ltd.
Bisphenol A causes hyperactivity in the rat concomitantly with impairment of tyrosine hydroxylase immunoreactivity
Authors: Ishido Masami , Masuo Yoshinori , Kunimoto Manabu , Oka Syuichi , Morita Masatoshi 
Published: April 2004

AbstractWe examined the effects of bisphenol A, an endocrine disruptor, on rat behavioral and cellular responses. Single intracisternal administration of bisphenol A (0.2‐20 μg) into 5‐day‐old male Wistar rats caused significant hyperactivity at 4–5 weeks of age. Rats were about 1.6‐fold more active in the nocturnal phase after administration of both 2 and 20 μg of bisphenol A than were control rats. The response was dose‐dependent. Based on DNA macroarray analyses of the midbrain, bisphenol A decreased by more than twofold gene expression levels of the dopamine D4 receptor at 4 weeks of age and the dopamine transporter at 8 weeks of age. Furthermore, bisphenol A decreased by more than twofold gene expression levels of the dopamine D4 receptor at 4 weeks of age and the dopamine transporter at 8 weeks of age. We conclude that bisphenol A affected central dopaminergic system activity, resulting in hyperactivity due most likely to a large reduction of tyrosine hydroxylase activity in the midbrain. © 2004 Wiley‐Liss, Inc.
Synaptotagmin IV overexpression inhibits depolarization‐induced exocytosis in PC12 cells
Authors: Machado Hidevaldo B. , Liu Wei , Vician Linda J. , Herschman Harvey R. 
Published: April 2004

AbstractDepolarization‐induced vesicle exocytosis is a complex mechanism involving a number of proteins. In this process, synaptotagmins work as members of the Ca2+‐sensing system that triggers the fusion of the synaptic vesicle with the plasma membrane. Synaptotagmin IV (SytIV), an immediate‐early gene induced by depolarization in PC12 pheochromocytoma cells and in the hippocampus, has been suggested to work as a negative regulator of neurotransmitter release. Unlike other synaptotagmins, SytIV has an evolutionarily conserved substitution of an aspartate to a serine in the Ca2+ coordination site of its C2A domain, preventing SytIV from binding anionic lipids in a Ca2+‐dependent fashion. We used the secretion of human growth hormone (hGH) as a reporter system with which to examine the effects of overexpressing SytIV and other depolarization‐induced immediate‐early genes (the protein kinases KID‐1, SIK, and PIM‐1 and the transcription factors rTLE3 and Nurr1) on depolarization‐induced vesicle exocytosis in PC12 cells. SytIV overexpression resulted in decreased depolarization‐induced hGH release. However, conversion of the unique serine in SytIV to an aspartate eliminated this inhibitory activity. In addition, rTLE3 overexpression produced only a modest increase in spontaneous vesicle exocytosis, whereas KID‐1, SIK, PIM‐1, and Nurr1 overexpression had no effect on depolarization‐induced exocytosis. © 2004 Wiley‐Liss, Inc.
Estradiol alters transcription factor gene expression in primate prefrontal cortex
Authors: Wang J. , Cheng C.M. , Zhou J. , Smith A. , Weickert C. Shannon , Perlman W.R. , Becker K.G. , Powell D. , Bondy C.A. 
Published: April 2004

AbstractEstrogen protects neurons from a variety of experimental insults in vitro, and is thought to protect from acute and chronic neurodegenerative processes in vivo. Estrogen also enhances higher‐level cognitive functions that are centered in the dorsolateral prefrontal cortex (DLPFC) in human and non‐human primates. To investigate genomic mechanisms involved in estrogenic effects on the primate brain in vivo, we compared transcription factor mRNA and protein expression in the DLPFC of ovariectomized rhesus monkeys treated with either vehicle or estradiol (E2). c‐FOS, E2F1, and general transcription factor IIB (TFIIB) mRNA and protein expression were altered significantly by short‐term E2 treatment, as shown by DNA array, in situ hybridization, and immunohistochemical and immunoblot evaluations. C‐FOS expression was increased significantly whereas E2F1 and TFIIB levels were decreased in the DLPFC of E2‐treated animals. These transcription factors were concentrated in cortical pyramids, as were estrogen receptors α and β. These data indicate that estrogen may have direct as well as indirect effects on neuronal gene expression in the primate prefrontal cortex. © 2004 Wiley‐Liss, Inc.
Cytidine‐5′‐diphosphocholine affects CTP‐phosphocholine cytidylyltransferase and lyso‐phosphatidylcholine after transient brain ischemia
Authors: Adibhatla Rao Muralikrishna , Hatcher James F. , Dempsey Robert J. 
Published: April 2004

AbstractCytidine‐5′‐diphosphocholine (CDP‐choline, also referred as citicoline), the key intermediate in phosphatidylcholine (PtdCho) synthesis, provided significant benefit in experimental central nervous system (CNS) injury including cerebral ischemia. CDP‐choline is synthesized by CTP:phosphocholine cytidylyltransferase (CCT), the key rate‐limiting enzyme in PtdCho synthesis. Phospholipase A2 (PLA2) hydrolyzes PtdCho to produce free fatty acids and lyso‐PtdCho, an inhibitor of CCT. We investigated the status of CCT and lyso‐PtdCho after 10‐min transient brain ischemia in gerbils with reperfusion up to 2 days. Ischemia with no reperfusion resulted in loss of CCT activity in cytosol (408 ± 8 pmol/min/mg protein compared to sham 695 ± 45; P < 0.01) and membrane (383 ± 61 compared to sham 532 ± 54; P < 0.05). CCT activity remained low over 24‐hr reperfusion, and returned to sham levels at Day 2 in membrane but remained low in cytosol. CDP‐choline significantly increased CCT activity in cytosol at 1 hr reperfusion (saline, 339 ± 35 compared to CDP‐choline, 430 ± 70; P < 0.05) and in membrane at 6 hr (saline, 381 ± 32 compared to CDP‐choline, 489 ± 50; P < 0.01) and 24 hr (saline, 417 ± 24 compared to CDP‐choline, 594 ± 45; P < 0.01), but had no effect on CCT activity at Day 2. Lyso‐PtdCho increased at 1‐hr reperfusion (219 ± 5 nmol/g tissue compared to sham, 92 ± 8; P < 0.01), and remained elevated over 2 days. CDP‐choline attenuated lyso‐PtdCho levels at 1‐hr reperfusion (162 ± 21, P < 0.01 compared to saline). These data indicate that PtdCho synthesis is impaired after brain ischemia, and CDP‐choline may increase PtdCho levels by attenuating the loss of CCT activity and lyso‐PtdCho formation. © 2004 Wiley‐Liss, Inc.
Effect of cell density on intracellular levels of the Alzheimer's amyloid precursor protein
Authors: Rebelo Sandra , Henriques Ana Gabriela , da Cruz e Silva Edgar F. , da Cruz e Silva Odete A.B. 
Published: April 2004

AbstractThe precise function of APP (Alzheimer's amyloid precursor protein) remains to be fully elucidated, but various lines of evidence suggest that it may be involved in cell adhesion processes. Because APP is a transmembrane glycoprotein, variations in its expression level may have direct bearing on its putative role in cell adhesion. Our results revealed that although APP levels did not change markedly with increasing cell density (ICD), there was a small but reproducible increase in APP expression at subconfluent conditions. Higher expression APP levels led to corresponding increases in the amount of APP processed and secreted APP (sAPP) released into the cell media. Given that phorbol esters stimulate the non‐amyloidogenic pathway at the expense of reducing production of Aβ (the peptide found deposited as neuritic plaques in the brains of patients with Alzheimer's disease), thus providing an interesting therapeutic focus, we tested the effect of the phorbol 12‐myristate 13‐acetate (PMA) on APP processing at ICD. PMA not only stimulated sAPP release at all densities tested, but also produced a corresponding decrease in the intracellular levels of APP. Further experimentation revealed that increased APP expression with ICD was dependent on factors present in conditioned medium. Interestingly, exposing cells to the Aβ peptide itself could mimic these results, thus providing evidence for a potential positive feedback mechanism between Aβ production and intracellular APP levels. © 2004 Wiley‐Liss, Inc.
Antipsychotics increase microtubule‐associated protein 2 mRNA but not spinophilin mRNA in rat hippocampus and cortex
Authors: Law Amanda J. , Hutchinson Louise J. , Burnet Philip W.J. , Harrison Paul J. 
Published: April 2004

AbstractAntipsychotic (neuroleptic) drugs induce structural alterations in synaptic terminals and changes in the expression of presynaptic protein genes. Whether there are also changes in corresponding postsynaptic (dendritic) markers has not been determined. We describe the effect of 14‐day treatment with typical (haloperidol, chlorpromazine) or atypical (clozapine, olanzapine, risperidone) antipsychotics on the expression of two dendritic protein genes, microtubule‐associated protein 2 (MAP2) and spinophilin, using in situ hybridization, in the rat hippocampus, retrosplenial, and occipitoparietal cortices. MAP2 mRNA was increased modestly in the dentate gyrus and retrosplenial cortex by chlorpromazine, risperidone, and olanzapine and in the occipitoparietal cortex by chlorpromazine, haloperidol, and risperidone. None of the antipsychotics affected spinophilin mRNA in any area. Overall, these results show a modulation of MAP2 gene expression, likely reflecting functional or structural changes in the dendritic tree in response to some typical and atypical antipsychotics. The lack of change in spinophilin mRNA suggests that dendritic spines are not affected selectively by the drugs. The data provide further evidence that antipsychotics regulate genes involved in synaptic structure and function. Such actions may underlie their long‐term effects on neural plasticity in areas of the brain implicated in the pathology of schizophrenia. © 2004 Wiley‐Liss, Inc.