bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functionalized Multiwalled Carbon Nanotubes Through In Situ Electropolymerization of Brilliant Cresyl Blue for Determination of Epinephrine
Authors: Yi Hongchao , Zheng Dongyun , Hu Chengguo , Hu Shengshui 
Published: March 2008

AbstractIn this work, a polymeric brilliant cresyl blue (BCB) and dihexadecyl phosphate (DHP) dispersed Multi‐walled carbon nanotubes (MWNTs) composite film modified glass carbon electrode (PBCB‐MWNTs‐DHP/GCE) denoted as epinephrine (EP) sensor was prepared by an in‐situ electropolymerization method. The electrochemical response of EP at the sensor is much better. Voltammetric investigations indicated that the improved response of EP at the sensor mainly arose from the enhanced adsorption of EP at PBCB‐MWNTs‐DHP film, perhaps through the hydrogen bonding and π–π interactions between EP and PBCB. The sensor was applied to the determination of EP in injection by a standard addition method and the results were satisfied.
Electrocatalytic Reduction of Nitrite by Phosphotungstic Heteropolyanion. Application for Its Simple and Selective Determination
Authors: Ojani Reza , Rahmanifar Mohamad‐Safi , Naderi Padideh 
Published: March 2008

AbstractThree couples of reversible redox peaks of the PW12O403− (PW12) anion, which are composed of two one‐electron and one two‐electron processes occur in the potential range from +0.25 to −0.7 V in aqueous solutions. The electrocatalytic reduction of nitrite has been studied by the first redox couple of the PW12 anion at the surface of a carbon paste electrode. Cyclic voltammetric and chronoamperometric techniques were used to investigate the suitability of PW12 anion as a mediator for nitrite electrocatalytic reduction in aqueous solution with strongly acidic concentration of H2SO4. Results showed that H2SO4 1.00 M is the best medium for this purpose. In the optimum concentration of H2SO4, the electrocatalytic ability about 500 mV can be seen and the homogeneous second‐order rate constant (ks) for nitrite coupled catalytically to PW12 anion was calculated as 2.52×103 M−1 s−1 using the Nicholson–Shain method. According to our voltammetric experiments, the catalytic reduction peak current was linearly dependent on the nitrite concentration and the linearity range obtained was 3×10−5 to 1.00×10−3 M. The detection limit has been found to be 2.82×10−5 M (2σ). This method has been applied as a selective, simple, and precise method for determination of nitrite in real samples.
Masked smoking‐related images modulate brain activity in smokers
Authors: Zhang Xiaochu , Chen Xiangchuan , Yu Yongqiang , Sun Delin , Ma Ning , He Sheng , Hu Xiaoping , Zhang Daren 
Published: March 2008

AbstractThe questions of whether and how indiscriminate drug‐related stimuli could influence drug‐users are important to our understanding of addictive behavior, but the answers are still inconclusive. In the present preliminary functional magnetic resonance imaging study using a backward masking paradigm, the effect of indiscriminate smoking‐related stimuli on 10 smokers and 10 nonsmokers was examined. The BOLD response showed a significant reduction (P = 0.001) in the right amygdala of smokers when they viewed but did not perceive masked smoking‐related stimuli, while no significant differences were found in the nonsmoker group. More voxels in anterior cingulate cortex were negatively correlated with the amygdala during the masked smoking‐related picture condition in smokers but not in nonsmokers, whereas more positively correlated voxels were observed during the masked neutral condition. The BOLD response in drug‐users indicates the amygdala responds to drug‐related stimuli that are below the perceptual threshold. The functional connectivity data suggest a functional interaction between the amygdala and the anterior cingulate cortex when drug users view 33ms back‐masked drug‐related stimuli. This observation suggests that the amygdala plays an important role in the indiscriminate drug‐related cue process. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Large‐scale neural model validation of partial correlation analysis for effective connectivity investigation in functional MRI
Authors: Marrelec G. , Kim J. , Doyon J. , Horwitz B. 
Published: March 2008

AbstractRecent studies of functional connectivity based upon blood oxygen level dependent functional magnetic resonance imaging have shown that this technique allows one to investigate large‐scale functional brain networks. In a previous study, we advocated that data‐driven measures of effective connectivity should be developed to bridge the gap between functional and effective connectivity. To attain this goal, we proposed a novel approach based on the partial correlation matrix. In this study, we further validate the use of partial correlation analysis by employing a large‐scale, neurobiologically realistic neural network model to generate simulated data that we analyze with both structural equation modeling (SEM) and the partial correlation approach. Unlike real experimental data, where the interregional anatomical links are not necessarily known, the links between the nodes of the network model are fully specified, and thus provide a standard against which to judge the results of SEM and partial correlation analyses. Our results show that partial correlation analysis from the data alone exhibits patterns of effective connectivity that are similar to those found using SEM, and both are in agreement with respect to the underlying neuroarchitecture. Our findings thus provide a strong validation for the partial correlation method. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Microwave assisted extraction for the determination of ethyl glucuronide in urine by gas chromatography‐mass spectrometry
Authors: Freire Iván Álvarez , Barrera Ana María Bermejo , Silva Purificación Cid , Duque María Jesús Tabernero , Gómez Purificación Fernández , Eijo Patricia López 
Published: March 2008

AbstractAlcohol is the most frequently abused ‘addictive substance’ that causes serious social problems throughout the world; thus alcoholism is of particular interest in clinical and forensic medicine. Ethyl glucuronide (EtG) is a marker of recent alcohol consumption that detects alcohol use reliably over a definite time period. The present paper describes a new method for the determination of EtG in urine. It was based both on microwave assisted extraction (MAE) to extract the analyte from urine samples, and gas chromatography‐mass spectrometry (GC‐MS) to identify and quantify the EtG in selected ion monitoring (SIM) mode. The method was applied to 33 urine samples from alcohol users, obtaining positive results in all cases. It was fully validated including a linear range (0.1–100 µg ml−1) and the main precision parameters. In summary, the use of microwave assisted extraction turned out to be a substantially simpler, faster and more sensitive procedure than any other conventional sample preparations. Copyright © 2008 John Wiley & Sons, Ltd.
Inhibition by vitamin C of apoptosis induced by N‐nitrosamines in HepG2 and HL‐60 cells
Authors: Arranz Nuria , Haza Ana I. , García Almudena , Delgado Ma Eugenia , Rafter Joseph , Morales Paloma 
Published: March 2008

AbstractThe aim of this study was to evaluate the effect of vitamin C towards N‐nitrosopyrrolidine (NPYR)‐ and N‐nitrosodimethylamine (NDMA)‐induced apoptosis in human hepatoma (HepG2) and leukemia (HL‐60) cell lines using flow cytometry analysis and the terminal deoxynucleotidyl transferase‐mediated dUTP nick end labelling assay (TUNEL). None of the vitamin C concentrations tested (1–100 µm) caused cytotoxicity in HepG2 cells. However, there were significant losses of HL‐60 cells viability, measured by MTT assay, 72 h after treatment with 50 and 100 µm vitamin C (29 and 46%, respectively). Moreover, an increase of lactate dehydrogenase release was significant with 50 µm at 72 h (28%) and with 100 µm of vitamin C at 48 and 72 h (27 and 36%, respectively). Also, the percentage of apoptotic HL‐60 cells found in TUNEL assay increased to 21% when they were treated with 100 µm vitamin C for 72 h. Thus, in subsequent simultaneous treatments with NPYR (30 and 50 mm) or NDMA (27 and 68 mm) and vitamin C, concentrations of 5–50 µm vitamin C were used. Our results revealed that vitamin C, at all concentrations and times tested, reduced the apoptosis induced by NPYR and NDMA in both cell lines, showing a similar effect in HepG2 and HL‐60 cells towards NPYR (50 mm) — 65 and 63% of reduction, respectively — whereas towards NDMA (27 mm) the inhibition was higher in HL‐60 than in HepG2 cells — 75 and 57%, respectively. Therefore, our findings suggest that inhibition of apoptosis may be one of the mechanisms by which vitamin C exerts its protective effect. Copyright © 2008 John Wiley & Sons, Ltd.
Role of hematopoietic microenvironment in prolonged impairment of B cell regeneration in age‐related stromal‐cell‐impaired SAMP1 mouse: effects of a single dose of 5‐fluorouracil
Authors: Tsuboi Isao , Hirabayashi Yoko , Harada Tomonori , Koshinaga Morimichi , Kawamata Tatsuro , Kanno Jun , Inoue Tohru , Aizawa Shin 
Published: March 2008

AbstractIn this study, we examined the age‐associated defect of stromal cells, which support B cell development, treated with 5‐fluorouracil (5‐FU) to induce severe perturbation of hematopoiesis, including B lymphocyte development, using SAMP1 mice exhibiting senescence‐mimicking stromal‐cell impairment after 30 weeks of age. Significant findings of this study are as follows: first, a marked and prolonged decrease in number of CFU‐preB cells in non‐SCI mice (58% of the steady‐state level) associated with more markedly depressed number of CFU‐preB cells in SCI mice (20% of the steady‐state level), despite the absence of difference in the number of CFU‐GMs during the period; second, in the non‐SCI mice, a significant and prolonged up‐regulation of GM‐CSF and IL‐6, positive regulators of myelopoiesis and suppressive factors of B lymphopoiesis, was observed. In SCI mice, greater and prolonged suppression of B lymphopoiesis was clearly demonstrated by the significant up‐regulation of the negative regulator TNF‐α associated with the concomitant marked down‐regulation of the positive regulator SDF‐1, although the increases of GM‐CSF and IL‐6 were limited. That is, ‘negative complementation’ makes preB recovery after 5‐FU treatment impaired and prolonged. Principal component analysis clearly showed differences in the cytokine expression patterns in both early and later phases and the time course of the expression pattern of each cytokine between SCI and non‐SCI mice without supervising information. An impaired regulation of the expressions of not only positive but also negative regulators after 5‐FU treatment was, in part, the cause of the impaired regeneration of CFU‐preB cells in SCI mice. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of inflammation on kidney function and pharmacokinetics of COX‐2 selective nonsteroidal anti‐inflammatory drugs rofecoxib and meloxicam
Authors: Harirforoosh Sam , Jamali Fakhreddin 
Published: March 2008

AbstractChronic arthritis adversely affects glomerular function and nonsteroidal anti‐inflammatory drugs (NSAIDs) reduce electrolyte urinary excretion. In addition, both acute and chronic inflammations may alter clearance of drugs. We studied (a) the effects of inflammation on the renal function and pharmacokinetics of rofecoxib and meloxicam; (b) whether inflammation could exacerbate reduced electrolytes excretion changes observed with NSAIDs; and (c) the influence of inflammation on distribution of these drugs into the kidney. Single oral doses of rofecoxib (10 mg kg−1), meloxicam (3 mg kg−1) or placebo were administered to normal or pre‐adjuvant arthritic rats. Blood and urine samples were collected for the measurement of plasma nitrite, BUN and creatinine. The urinary excretion of sodium and potassium was also determined. Nitrite, BUN and plasma creatinine were increased starting on day 9 in the groups with inflammation. Sodium and potassium excretion rates were not affected by inflammation. Meloxicam did not alter the electrolyte excretion in any of the groups. Rofecoxib significantly decreased sodium and potassium excretion in normal rats and potassium excretion in inflamed rats. Inflammation significantly increased plasma concentrations of rofecoxib, but not meloxicam. The ratios of the kidney:plasma concentrations were not significantly altered by inflammation following either drug. Inflammation altered kidney function, demonstrated by increases in BUN and plasma creatinine. However, it did not influence the urinary electrolytes excretion. Since we have observed similar patterns of the effect of NSAIDs on kidney under healthy and inflammatory conditions, one may conclude that inflammation does not exacerbate the adverse effect. Copyright © 2008 John Wiley & Sons, Ltd.
Combined treatment with naringin and vitamin C ameliorates streptozotocin‐induced diabetes in male Wistar rats
Authors: Punithavathi V. R. , Anuthama R. , Prince P. Stanely Mainzen 
Published: March 2008

AbstractDiet and nutrition have substantial impact on reducing the incidence of diabetes mellitus, where oxidative stress is an important etiopathological factor. The combined protective role of low dose of naringin (15 mg kg−1) and vitamin C (25 mg kg−1) and high dose of naringin (30 mg kg−1) and vitamin C (50 mg kg−1) on streptozotocin (STZ)‐induced toxicity was studied in male Wistar rats. To induce type II diabetes mellitus, rats were injected with STZ intraperitoneally at a dose of 45 mg kg−1 body weight. STZ‐induced diabetic rats showed significant increase in blood glucose, water intake, food intake and glycated hemoglobin and significant decrease in plasma insulin, total hemoglobin, body weight and liver glycogen. Diabetic rats also showed significant decrease in the activity of hexokinase and significant increase in the activities of glucose‐6‐phosphatase and fructose‐1,6‐bisphosphatase in liver and kidney. The levels of plasma thiobarbituric acid reactive substances, lipid hydroperoxides and vitamin E were elevated while the level of reduced glutathione was decreased in diabetic rats. Glycoprotein components such as hexose, hexosamine, fucose and sialic acid were increased in plasma, liver and kidney of diabetic rats. Oral administration of high doses of naringin (30 mg kg−1) and vitamin C (50 mg kg−1) to diabetic rats for a period of 21 days normalized all the above‐mentioned biochemical parameters. The effect exerted by naringin (30 mg kg−1) and vitamin C (50 mg kg−1) was similar to the effect exerted by insulin (6 units kg−1). Thus, our study shows the antihyperglycemic and antioxidant effects of naringin and vitamin C in STZ‐induced type II diabetes mellitus in rats. Copyright © 2008 John Wiley & Sons, Ltd.
In vitro oxime protection of human red blood cell acetylcholinesterase inhibited by diisopropyl‐fluorophosphate
Authors: Lorke D. E. , Hasan M. Y. , Arafat K. , Kuča K. , Musilek K. , Schmitt A. , Petroianu G. A. 
Published: March 2008

AbstractOximes are enzyme reactivators used in treating poisoning with organophosphorus cholinesterase (AChE) inhibitors. The oxime dose which can be safely administered is limited by the intrinsic toxicity of the substances such as their own AChE‐inhibiting tendency. Clinical experience with the available oximes is disappointing. To meet this need, new AChE reactivators of potential clinical utility have been developed. The purpose of the study was to estimate in vitro both the intrinsic toxicity and the extent of possible protection conferred by established (pralidoxime, obidoxime, HI‐6, methoxime, trimedoxime) and experimental (K‐type) oximes, using diisopropyl‐fluoro‐phosphate (DFP) as an AChE inhibitor. The IC50 of DFP against human red blood cell AChE was determined (∼120 nm). Measurements were then repeated in the presence of increasing oxime concentrations, leading to an apparent increase in DFP IC50. Calculated IC50 values were plotted against oxime concentrations to obtain an IC50 shift curve. The slope of this shift curve (tanα) was used to quantify the magnitude of the protective effect (nm IC50 increase per µm oxime). We show that, in the case of a linear relationship between oxime concentration and IC50, the binding constant K, determined using the Schild equation, equals IC50/DFP/tanα. Based on the values of tanα and of the binding constant K, some of the new K‐oxime reactivators are far superior to pralidoxime (tanα = 0.8), obidoxime (1.5), HI‐6 (0.8), trimedoxime (2.9) and methoxime (5.9), with K‐107 (17), K‐108 (20), and K‐113 (16) being the outstanding compounds. Copyright © 2008 John Wiley & Sons, Ltd.
Vinylic telluride derivatives as promising pharmacological compounds with low toxicity
Authors: Borges V. C. , Savegnago L. , Pinton S. , Jesse C. R. , Alves D. , Nogueira C. W. 
Published: March 2008

AbstractThe aim of the present study was to evaluate pharmacological and toxicological properties of (Z)‐2‐(methylthio)‐1‐(butyltelluro)‐1‐phenylethene 1a, (Z)‐1‐(4‐methylphenylsulfonyl)‐2‐(phenyltelluro)‐2‐phenylethene 1b, (Z)‐2‐(butyltelluro)‐1‐(benzylthio)‐1‐heptene 1c and (Z)‐2‐(phenylthio)‐1‐(butyltelluro)‐1‐phenylethene 1d. In vitro, vinylic telluride derivatives 1a, 1d and 1c were more effective in reducing lipid peroxidation than compound 1b. The maximal inhibitory effect of vinylic telluride derivatives on lipid peroxidation was in the following order: 1a = 1d > 1c > 1b. Compound 1b was more potent in inhibiting δ‐ALA‐D activity (δ‐aminolevulinate dehydratase) than compounds 1c and 1d. Based on the in vitro properties presented by compounds 1a (an antioxidant) and 1b (a pro‐oxidant), toxicological parameters were assessed in vivo and ex vivo in rats. Calculated LD50 of compounds 1a and 1b, administered by oral route, were 20.5 and 1.44 µmol kg−1, respectively. Compound 1b induced behavioral alterations in the open field test. Renal and spleenic δ‐ALA‐D activities were inhibited in rats treated orally with compound 1a. Compound 1b stimulated δ‐ALA‐D activity in liver and spleen of rats. Rats treated with compound 1b had increased hepatic, renal and spleenic lipid peroxidation. Renal and hepatic markers were not altered when compounds 1a and 1b were administered to rats at doses of around LD50, while compound 1a at high doses changed aspartate aminotransferase activity and urea levels. Based on in vitro results, this study demonstrated that compounds 1a and 1d are promising antioxidant compounds. Ex vivo data reinforce compound 1a as a promising drug for more detailed pharmacological studies. Copyright © 2008 John Wiley & Sons, Ltd.
Surface modification of non‐woven poly (ethylene terephthalate) fibrous scaffold for improving cell attachment in animal cell culture
Authors: Zhang Weiyuan , Yi Xiaoping , Sun Xiangming , Zhang Yuanxing 
Published: March 2008

AbstractBACKGROUND: The development of carriers with biocompatible surfaces are required to meet the needs in animal cell culture. In this work, poly (ethylene terephthalate) (PET) fibrous scaffold surfaces were chemically modified to introduce diethylaminoethyl (DEAE) groups. A packed‐bed bioreactor with DEAE‐conjugated PET fibrous scaffolds was investigated for continuous production of HBsAg by r‐CHO cells.RESULTS: The changes of surface properties were characterized by surface hydrophilicity, Attenuated total reflectance (ATR) analysis, element measurement, and scanning electron microscopy. The results showed that this treatment could improve surface hydrophilicity and roughness. Using an r‐CHO cell line as model cells, the feasibility of the DEAE‐conjugated PET fibrous scaffold in animal cell culture was evaluated by means of cell attachment efficiency measurement, MTT (3‐(4,5)‐dimethylthiathiazo(‐z‐yl)‐3,5‐di‐phenytetrazoliumromide) assay, and scanning electron microscopy observation. Enhancement of cell attachment and proliferation was exhibited in the cell culture on DEAE‐conjugated PET fibrous scaffolds. r‐CHO cells were cultured for continuous HBsAg production in a packed‐bed bioreactor with DEAE‐conjugated PET fibrous scaffolds. A cell density of 1.2 × 107 cells mL−1 working volume, cell viability of 92.8% and maximum HBsAg concentration of 3.1 mg L−1 were achieved.CONCLUSION: The packed‐bed bioreactor system with DEAE‐conjugated PET fibrous scaffolds has the potential for industrial animal cell culture application. Copyright © 2008 Society of Chemical Industry
Simultaneous sulfide and acetate oxidation under denitrifying conditions using an inverse fluidized bed reactor
Authors: Beristain‐Cardoso Ricardo , Texier Anne‐Claire , Sierra‐Álvarez Reyes , Field Jim A , Razo‐Flores Elías , Gómez Jorge 
Published: March 2008

AbstractBACKGROUND: Simultaneous removal of sulfur, nitrogen and carbon compounds from wastewaters is a commercially important biological process. The objective was to evaluate the influence of the CH3COO−/NO3− molar ratio on the sulfide oxidation process using an inverse fluidized bed reactor (IFBR).RESULTS: Three molar ratios of CH3COO−/NO3− (0.85, 0.72 and 0.62) with a constant S2−/NO3− molar ratio of 0.13 were evaluated. At a CH3COO−/NO3− molar ratio of 0.85, the nitrate, acetate and sulfide removal efficiencies were approximately 100%. The N2 yield (g N2 g−1 NO3−‐N consumed) was 0.81. Acetate was mineralized, resulting in a yield of 0.65 g inorganic‐C g−1 CH3COO−‐C consumed. Sulfide was partially oxidized to S0, and 71% of the S2− consumed was recovered as elemental sulfur by a settler installed in the IFBR. At a CH3COO−/NO3− molar ratio of 0.72, the efficiencies of nitrate, acetate and sulfide consumption were of 100%, with N2 and inorganic‐C yields of 0.84 and 0.69, respectively. The sulfide was recovered as sulfate instead of S0, with a yield of 0.92 g SO42−‐S g−1 S2− consumed.CONCLUSIONS: The CH3COO−/NO3− molar ratio was shown to be an important parameter that can be used to control the fate of sulfide oxidation to either S0 or sulfate. In this study, the potential of denitrification for the simultaneous removal of organic matter, sulfide and nitrate from wastewaters was demonstrated, obtaining CO2, S0 and N2 as the major end products. Copyright © 2008 Society of Chemical Industry