bluuebunny/crossref_metadata_2025_split huggingface dataset:
In Vivo Effects of Insulin and Free Fatty Acids on Matrix Metalloproteinases in Rat Aorta
Authors: Boden Guenther , Song Weiwei , Pashko Laura , Kresge Karen 
Published: November 2007

OBJECTIVE—Obesity is associated with insulin resistance, hyperinsulinemia, elevated plasma free fatty acid (FFA), and increased risk for atherosclerotic vascular disease (ASVD). A part of this increased risk may be due to enhanced activation of matrix metalloproteinases (MMPs). Here, we have examined the effects of physiologically elevated levels of insulin and FFA on three MMPs and their inhibitors (tissue inhibitors of MMP [TIMPs]) in aortic tissue of male rats during euglycemic-hyperinsulinemic clamping.
RESEARCH DESIGN AND METHODS—Four-hour euglycemic-hyperinsulinemic clamps with infusion of saline/glycerol, lipid/heparin, or insulin with or without lipid/heparin were performed in alert unrestrained male rats.
RESULTS—Hyperinsulinemia increased MMP-2 (∼6-fold), MMP-9 (∼13-fold), membrane type 1-MMP (MT1-MMP; ∼8-fold) (all Western blots), and gelatinolytic activity (zymography) of MMP-2 (2-fold), while not affecting TIMP-1 and TIMP-2. Insulin increased IRS-1–associated PI 3-kinase (PI3K), extracellular signal–regulated kinases 1/2 (ERK1/2), and c-jun NH2-terminal kinase (JNK) (by Western blots with phospho-specific antibodies). FFA augmented the insulin-mediated increases in MMP-2 (from ∼6- to ∼11-fold), MMP-9 (from ∼3- to ∼23-fold), MT1-MMP (from ∼8- to ∼20-fold), MMP-2 gelatinolytic activity (from 2- to 3-fold), and JNK and p38 mitogen-activated protein kinase (MAPK) activities but decreased insulin-mediated activation of PI3K and ERK1/2. Raising FFA without raising insulin affected neither MMPs nor TIMPs.
CONCLUSIONS—FFA augmented insulin stimulation of the MMP/TIMP balance of three proatherogenic MMPs and increased activities of two MAPKs (JNK and p38 MAPK), both of which are known to stimulate the production of proinflammatory cytokines. This may, over time, increase degradation of extracellular matrix and together with inflammatory changes promote development of ASVD.
Study of Heavy Metal Speciation in Sediments Impacted with Crude Oil in the Niger Delta, Nigeria
Authors: Iwegbue Chukwujindu Maxwell Azubuike , Arimoro Francis Ofurum , Nwozo Sarah Onyenibe 
Published: November 2007

AbstractSequential chemical extraction was used to assess trace metal speciation and availability in sediments from Abalagada‐Aboh catchments in the Niger Delta that have received significant impact of crude oil spillage. The proportions of trace metals in the various geochemical fractions were variable. The result of speciation among the five geochemical fractions indicates that Cd was associated with easily exchangeable/adsorbed and carbonate fractions, Cu and Cr predominantly to organic and residual fraction, Pb was associated with Fe‐Mn oxides and carbonate fractions, Ni to residual and Fe‐Mn oxides, Mn was associated with Fe‐Mn oxides and residual and Zn was associated with carbonate and Fe‐Mn oxide fractions. The data revealed that Cd, Pb, Zn and Ni have high mobility indices and are thus relatively labile and bioavailable to aquatic flora and fauna.
Determination of Quats in Beverages and Urine Samples by Capillary Zone Eletrophoresis
Authors: Aulakh Jatinder Singh , Fekete Agnes , Malik Ashok Kumar , Schmitt‐Kopplin Ph. , Mahajan R.K 
Published: November 2007

AbstractConditions have been developed for simultaneous determination of paraquat (PQ) and diquat (DQ) by capillary zone electrophoresis (CZE) with diode array detector (DAD) after their preconcentration by solid phase extraction using Megabond Elut C18 and Strata X 33 μm Polymeric sorbent cartridges. Conditions were optimised with reference to pH, EDTA concentration in sodium acetate acetic acid buffer of pH (3.8) with 3‐8 % of methanol, ethanol and acetonitrile as organic modifier in the background electrolyte. UV detection with variable wavelength was used to determine each compound at its maximum absorption providing an excellent sensitivity. The recovery of these compounds from water samples spiked at different levels was more than 90 %. The limit of detection (S/N=3) obtained for milli‐Q water when spiked with standards was 0.17 ppm for DQ and 0.19 ppm for PQ, in tap water samples it was found to be 0.27 ppm for DQ and 0.31 ppm for PQ, in cola beverages it was found to be 0.29 ppm for DQ and 0.35 ppm for PQ, and for the urine samples it was 0.36 ppm for diquat and 0.41 ppm for the PQ without preconcentration. After preconcentration using polymeric cartridge the detection limit was reduced to 2.5 ppb for DQand 3 ppb for PQ for the milli‐Q water. These detection limits allows for the analysis of these compounds at the levels established by the US Environmental Protection agency.
Electrochemical Oxidation and Determination of Norepinephrine in the Presence of Ascorbic Acid and Uric Acid at a Poly(Calconcarboxylic Acid)‐Modified Electrode
Authors: Yao Hong , Sun Yuanyuan , Lin Xinhua , Tang Yuhai , Huang Liying 
Published: November 2007

AbstractA poly(calconcarboxylic acid) film was prepared originally via electrochemically depositing calconcarboxylic acid (CCA) on a glassy carbon electrode (GCE) by cyclic voltammetry (CV). The polymer showed excellent electrocatalytic activity to the oxidation of norepinephrine and could detect separately ascorbic acid (AA), norepinephrine (NE) and uric acid (UA) in their mixture. Separations of the oxidation peak potentials of NE‐AA and UA‐AA were 160 and 150 mV, respectively. Using differential pulse voltammetry (DPV), the peak current of NE was linearly dependent on its concentration within the range of 10–300 μmol L‐1. No interference was produced for the determination of NE in the presence of AA and UA. Owing to its good selectivity and robustness, the poly(CCA)‐modified GCE was used for the determination of NE in injections with satisfactory results.
Synthesis of 2‐Hydroxy‐3‐Methoxy Benzaldehyde Thiosemicarbazone (HMBATSC) and its Application for Direct and Second Derivative Spectrophotometric Determination of Palladium(II)
Authors: Srivani I. , Praveen Kumar A. , Reddy P. Raveendra , Reddy K.P.P.R. Mohan , Reddy V. Krishna 
Published: November 2007

Abstract2‐Hydroxy‐3‐methoxy benzaldehyde thiosemicarbazone (HMBATSC) has been synthesized and its analytical applications are investigated. A rapid, simple, sensitive and selective spectrophotometric method is developed for the determination of palladium (II) in aqueous dimethyl formamide (DMF). Palladium (II) forms a yellowish M2L3 complex with 2‐hydroxy‐3‐methoxy‐benzaldehyde green coloured thiosemicarbazone in the pH range 1.0‐7.0 at room temperature. The complex shows absorption maximum at 380nm with molar absorptivity and Sandell's sensitivity of 2.198 × 104 l mol‐1 cm‐1 and 0.049μg cm‐2 respectively. Beer's law is obeyed in the range of 0.426 to 4.257 μg ml‐1 of Pd (II). A second order derivative spectrophotometric ethod for the determination of palladium (II) has also been proposed. Interference of various diverse ions has been studied. The proposed method is successfully applied for the determination of palladium in alloy steels and in hydrogenation catalysts.
PVC Matrix Membrane Sensor for Potentiometric Determination of Triphenyltetrazolium Chloride and Ascorbic Acid
Authors: Mostafa Gamal Abdel‐Hafiz 
Published: November 2007

AbstractThe construction and performance characteristic of a potentiometric PVC membrane sensor for the determination of triphenyltetrazolium chloride (TPTCl) is described. The sensor is based on the use of triphenyltetrazolium (TPT)‐tetraphenylborate (TPB) ion pair as ion exchange sites in PVC matrix in presence of dioctylphathalte as plasticizer. The TPT membrane sensor shows a stable, near‐Nernestian response for 6×10‐6 ‐ 1×10‐2 M TPTCl at 25 °C over the pH range 3‐10 with cationic slope of 57.0 ± 0.5. The lower detection limit is 4×0‐6M and the response time is 10‐30 sec. Selectivity coefficients for TPTCl relative to a number of different cations and anions were investigated, which there is negligible interferences. However, iodide, bromide and thiocyanate were interfering. The determination of 2.0‐ 3340.0 μg/ml of TPTCl in aqueous solutions shows an average recovery of 98.5 % and a mean relative standard deviation of 1.9 at 160μg/ml. The proposed method has been used for indirect potentiometric determination of ascorbic acid in its pharmaceutical formulations which are comparable favorably with those of British pharmacopoeia method. Precipitation titrations involving TPTCl as titrant are monitored with NaTPB using the proposed membrane sensor; the inflection break is about 300 mV.
Flotation Separation and Flame Atomic Absorption Spectrometric Determination of Trace Amount of Lead in Some Environmental Samples
Authors: Hosseini Mohammad Saeid , Hassan‐ABADI Reyhaneh 
Published: November 2007

AbstractA flotation method based on formation of an ion‐associate complex between ferroin and Pb(II)‐thiosulfate complex is proposed for the quantitative separation and preconcentration of Pb(II) content in various environmental samples. The flotation process was carried out using a 250‐mL aliquot of the aqueous solution at the buffering pH of 8.50 in which the ion‐associate complex was floated at the interface of the aqueous/xylene phases. The ion‐associate complex was then dissolved in 5 mL of acidic solution of 0.05 M KClO3 and the Pb(II) content was determined by flame atomic absorption spectrometry (FAAS). By this method, a preconcentration factor of 50 can be achieved so that the determination of trace amounts of Pb(II) ions is feasible in the range of 1×10‐7 to 1.2×10‐6 M. The LOD and RSD (n=7) were obtained as 1.5×10‐8 M and 1.5 %, respectively. It was found that a large number of cations and anions even at high considerably foreign ion/Pb(II) ratios were not interfered. In treatment with a SRM water sample and a synthetic liquid extract of vegetable, the recoveries were more than 95 %s, which confirmed validity of the method. The method was satisfactorily applied for determining of trace amount of Pb(II) in some complex matrices.
Flow cytometry in the diagnosis of drug‐induced thrombocytopenia: Two illustrative cases
Authors: Scognamiglio Francesca , Corso Chiara , Madeo Domenico , Castaman Giancarlo , Visco Carlo , Borghero Carlo , Ruggeri Marco , Rodeghiero Francesco 
Published: November 2007

AbstractDrug‐induced thrombocytopenia is a challenging diagnosis in the clinical practice because of the many drugs or alternative causes that may be implicated. Exact identification of such drug(s) is required to guide future management and avoid re‐exposure. We describe two cases of isolated thrombocytopenia in which cytometric analysis, a readily available technique, allowed the identification of the causative drug in the context of complex therapies (rifampicin and abciximab causing late onset thrombocytopenia). Am. J. Hematol., 2008. © 2007 Wiley‐Liss, Inc.
Synthesis, crystal structure and magnetic property of a novel ion‐pair nickel(III) complex containing 1,2‐benzenedithiolate
Authors: Liu Guang‐Xiang , Huang Liang‐Fang , Ren Xiao‐Ming 
Published: November 2007

AbstractA new ion‐pair complex [1‐(4‐nitrobenzyl)pyridinium][Ni(bdt)2] (1), in which bdt2− = 1,2‐benzenedithiolate, has been synthesized and characterized. The X‐ray structure analysis shows that the anions are centrosymmetric, the two non‐equivalent anions form different uniform‐spaced stacking pattern and the weak H‐bonding interactions of CH…S were observed in 1. The temperature dependence of magnetic susceptibilities of 1 indicates ferromagnetic behavior in the antiferromagnetic exchange system, which may arise from spin‐canting. Copyright © 2007 John Wiley & Sons, Ltd.
Assessment of the severe weather environment in North America simulated by a global climate model
Authors: Marsh Patrick T. , Brooks Harold E. , Karoly David J. 
Published: November 2007

AbstractAnnual and seasonal cycles of convectively important atmospheric parameters for North America have been computed using the Community Climate System Model version 3 (CCSM3) Global Climate Model using a decade of CCSM3 data. Results for the spatial and temporal distributions of environments conducive to severe convective weather qualitatively agree with observational estimates from NCAR/NCEP global reanalyses, although the model underestimates the frequency of occurrence of severe weather environments. This result demonstrates the possibility for future studies aimed at determining possible changes in the distribution of severe weather environments associated with global climate change. Copyright © 2007 Royal Meteorological Society
The Pacific–North American pattern associated diabatic heating and its relationship to ENSO
Authors: Yu B. 
Published: November 2007

AbstractThe Pacific–North American (PNA) pattern associated atmospheric diabatic heating is examined by linearly isolating the influence of El Niño‐Southern Oscillation (ENSO). Both the vertically integrated and three‐dimensional (3D) diabatic heating are calculated on the basis of NCEP/NCAR reanalysis. The PNA‐related heating is dominated by anomalies in the eastern Pacific, with a north–south dipole structure in mid‐latitudes and in the northern subtropics. The tropical heating anomalies are rather weak, remarkably different from those related to ENSO variability, and may be characterized by the heating nonlinearity with anomalies in the vicinity of the western Pacific. The results provide further evidence of the independence of the PNA on ENSO from the diabatic heating point of view. Copyright © 2007 Royal Meteorological Society
The effects of pulsed electromagnetic fields on the cellular activity of SaOS‐2 cells
Authors: Martino Carlos F. , Belchenko Dmitry , Ferguson Virginia , Nielsen‐Preiss Sheila , Qi H. Jerry 
Published: November 2007

AbstractAlthough pulsed electromagnetic fields (PEMFs) have been used for treatments of nonunion bone fracture healing for more than three decades, the underlying cellular mechanism of bone formation promoted by PEMFs is still unclear. It has been observed that a series of parameters such as pulse shape and frequency should be carefully controlled to achieve effective treatments. In this article, the effects of PEMFs with repetitive pulse burst waveform on the cellular activity of SaOS‐2 osteoblast‐like cells were investigated. In particular, cell proliferation and mineralization due to the imposed PEMFs were assessed through direct cell counts, the MTT assay, tissue nonspecific alkaline phosphatase (ALP) and Alizarin Red S (ARS) staining. PEMF stimulation with repetitive pulse burst waveform did not affect metabolic activity and cell number. However, the ALP activity of SaOS‐2 cells and mineral nodule formation increased significantly after PEMF stimulation. These observations suggest that repetitive pulse burst PEMF does not affect cellular metabolism; however, it may play a role in the enhancement of SaOS‐2 cell mineralization. We are currently investigating cellular responses under different PEMF waveforms and Western blots for protein expression of bone mineralization specific proteins. Bioelectromagnetics 29:125–132, 2008. © 2007 Wiley‐Liss, Inc.
In vitro electrical impedance spectroscopy of human dentine: The effect of restorative materials
Authors: Rivas Berta , Botta Pablo M. , Varela Purificación , Martín Benjamín , Fondado Alfonso , Rivas Jose 
Published: November 2007

AbstractThe influence of different restorative materials on in vitro dielectric properties of sound dentine was investigated. The studied samples were three‐layer materials consisting of successive disks of dentine and silver amalgam or nanohybrid composite resin. Before being tested, the samples were maintained in physiological solution never more than 48 h from the extraction. Also, sections of intact dentine were similarly prepared for electrical measurements. Complex dielectric permittivity of these specimens was determined in a wide frequency range using the parallel‐plate capacitor technique. Very similar dielectric responses of intact dentine and amalgam‐dentine material were observed. This is explained on the basis of high dc conductivity exhibited by both samples. In contrast, resin‐dentine specimen revealed a much more insulating behavior. A simple theoretical model for heterogeneous systems could be applied to these dental three‐layer materials. The dielectric properties of restored dentine are strongly dependent on the kind of restorative material employed in each case. This suggests that electrical data should be used carefully in caries diagnosis on restored teeth. Bioelectromagnetics 29:163–168, 2008. © 2007 Wiley‐Liss, Inc.
Sodium butyrate stimulates monoclonal antibody over‐expression in CHO cells by improving gene accessibility
Authors: Jiang Zhou , Sharfstein Susan T. 
Published: November 2007

AbstractSodium butyrate treatment can increase the specific productivity of recombinant proteins in mammalian cells; however, it dramatically decreases cell growth and frequently leads to apoptosis. We have studied the responses of several Chinese hamster ovary (CHO) cells lines with different specific productivities (qP) to sodium butyrate treatment. Cell clones with lower productivities exhibited greater enhancement from butyrate treatment than cells with higher productivities. As we observed previously in cell clone characterization (Jiang et al., 2006. Biotechnol Prog 22: 313–318), heavy chain (HC) mRNA levels correlate very well with specific productivity and are amplified by butyrate treatment, indicating that sodium butyrate regulates the HC transcription. Sodium butyrate is an inhibitor of histone deacetylation, and possibly, increases gene transcription by enhancing gene accessibility to transcription factors. In this study, we applied DNase I footprinting to probe the HC and LC gene accessibility. We determined that more HC and LC gene copies are accessible by DNase I in sodium butyrate‐treated CHO cells than in untreated controls, demonstrating that sodium butyrate regulates gene transcription by improving gene accessibility. However, the increase in accessibility did not correlate with the increase in transcript abundance, suggesting that butyrate enhances transcription by other mechanisms as well. Biotechnol. Bioeng. 2008;100: 189–194. © 2007 Wiley Periodicals, Inc.
Individual and combined effects of the rolA, B, and C genes on anthraquinone production in Rubia cordifolia transformed calli
Authors: Shkryl Yuri N. , Veremeichik Galina N. , Bulgakov Victor P. , Tchernoded Galina K. , Mischenko Natalia P. , Fedoreyev Sergei A. , Zhuravlev Yuri N. 
Published: November 2007

AbstractIt is known that the rolA, rolB, and rolC genes of Agrobacterium rhizogenes T‐DNA affect processes of plant development and activate the synthesis of secondary metabolites in transformed plant cells. Although a synergistic activity of the rol genes on root formation is well‐documented, little is known about their individual and combined action on secondary metabolism. In the present investigation, we provide evidence indicating that individual rolA, rolB, and rolC genes are capable of increasing biosynthesis of anthraquinones (AQs) in transformed calli of Rubia cordifolia. The stimulatory effect was due to the increased transcription of a key gene of AQ biosynthesis, the isochorismate synthase (ICS) gene. The strongest AQ‐stimulating activity was shown for an R. cordifolia culture expressing rolB at high levels, where rolB ensured a 15‐fold increase of AQ accumulation compared with the control, non‐transformed calli. A tyrosine phosphatase inhibitor abolished the rolB‐induced increase of AQ production, thus indicating the involvement of tyrosine (de)phosphorylation in the rolB‐mediated AQ stimulation. The rolA‐ and rolC‐expressing cultures produced 2.8‐ and 4.3‐fold higher levels of AQs, respectively, when compared with the control calli. However, the effect of rolA, rolB, and rolC on AQ biosynthesis was not synergistic because rolA and rolC apparently attenuated the stimulatory effect of rolB on AQ biosynthesis. Therefore, the rol‐gene‐mediated signals that promote root formation and those which activate biosynthesis of secondary metabolites seem to have a point of divergence. Biotechnol. Bioeng. 2008;100: 118–125. © 2007 Wiley Periodicals, Inc.
Multivariate models for prediction of rheological characteristics of filamentous fermentation broth from the size distribution
Authors: Petersen Nanna , Stocks Stuart , Gernaey Krist V. 
Published: November 2007

AbstractThe main purpose of this article is to demonstrate that principal component analysis (PCA) and partial least squares regression (PLSR) can be used to extract information from particle size distribution data and predict rheological properties. Samples from commercially relevant Aspergillus oryzae fermentations conducted in 550 L pilot scale tanks were characterized with respect to particle size distribution, biomass concentration, and rheological properties. The rheological properties were described using the Herschel–Bulkley model. Estimation of all three parameters in the Herschel–Bulkley model (yield stress (τy), consistency index (K), and flow behavior index (n)) resulted in a large standard deviation of the parameter estimates. The flow behavior index was not found to be correlated with any of the other measured variables and previous studies have suggested a constant value of the flow behavior index in filamentous fermentations. It was therefore chosen to fix this parameter to the average value thereby decreasing the standard deviation of the estimates of the remaining rheological parameters significantly. Using a PLSR model, a reasonable prediction of apparent viscosity (µapp), yield stress (τy), and consistency index (K), could be made from the size distributions, biomass concentration, and process information. This provides a predictive method with a high predictive power for the rheology of fermentation broth, and with the advantages over previous models that τy and K can be predicted as well as µapp. Validation on an independent test set yielded a root mean square error of 1.21 Pa for τy, 0.209 Pa sn for K, and 0.0288 Pa s for µapp, corresponding to R2 = 0.95, R2 = 0.94, and R2 = 0.95 respectively. Biotechnol. Bioeng. 2008;100: 61–71. © 2007 Wiley Periodicals, Inc.