bluuebunny/crossref_metadata_2025_split huggingface dataset:
A simplified method for HPLC‐MS analysis of sterols in vegetable oil
Authors: Carretero Antonio Segura , Carrasco‐Pancorbo Alegría , Cortacero Sonia , Gori Alessandro , Cerretani Lorenzo , Fernández‐Gutiérrez Alberto 
Published: December 2008

AbstractWe have developed a liquid‐chromatographic method using atmospheric pressure chemical ionization (APCI)‐mass spectrometry (MS) detection in positive mode. This method was used to separate and identify 15 sterols and 2 dihydroxy triterpenes in saponified oils, enabling the analysis of these compounds directly from saponified samples without recourse to thin‐layer chromatography; this fact thus significantly simplifies the process. The analyses were made using a Waters Atlantis 5 µm dC18 150×2.1 mm column with a gradient of acetonitrile/water (0.01% acetic acid) at a flow rate of 0.5 mL/min and a column temperature of 30 °C. The quantification of several of these compounds in soybean oil, palm oil, seed oil, sunflower oil, olive‐pomace oil and virgin olive oil was carried out using their commercial standards, and the results were compared satisfactorily with the official method.
Rheological properties, oxidative stability and sensory evaluation of enzymatically synthesized medium‐ and long‐chain triacylglycerol‐based salad dressings
Authors: Koh Soo‐Peng , Arifin Norlelawati , Tan Chin‐Ping , Yusoff Mohd. Suria Affandi , Long Kamariah , Idris Nor Aini , Lai Oi‐Ming 
Published: December 2008

AbstractThe rheological properties of various oil‐based salad dressings were investigated. The shear rate‐shear stress study based on Power Law's model indicated pseudoplastic fluid behaviors of dressings prepared in this study. Soybean‐ and medium‐ and long‐chain triacylglycerols (MLCT)‐based dressings treated with different antioxidants showed similar rheological behaviors based on the changes in the storage modulus, loss modulus, viscosity profile and loss tangent in the frequency, amplitude and temperature sweep study. The time‐dependent study revealed similar thixotrophic properties between soybean‐ and MLCT‐based dressings. Addition of synthetic or natural antioxidants reduced the rate of oil deterioration in oil‐in‐water emulsion as a function of time. No significant differences (p >0.05) in hydrolytic reaction of all dressing systems were observed throughout the 3 months of storage at 20 °C. Quantitative descriptive analysis using trained panelists revealed no significant differences (p >0.05) either in salad oils or salad dressings except for MLCT‐based oils/dressings treated with oleoresin sage extracts, which showed darker and stronger odor intensity than other oil systems. Nevertheless, the overall quality of the physical appearance and organoleptic acceptability showed no significant differences (p >0.05) in all systems, indicating that MLCT‐based blends can be used as healthy functional oils to replace soybean oil in food dressing applications.
Oil chemical variation in walnut (Juglans regia L.) genotypes grown in Argentina
Authors: Martínez Marcela L. , Maestri Damián M. 
Published: December 2008

AbstractWalnut (Juglans regia L.) oil (WO) from the varieties Chandler, Franquette, Hartley, Lara, Mayette, Serr, Sorrento and Tulare were studied in order to evaluate genotypical variations in fatty acid (FA) and volatile compositions, tocopherol content and oxidative parameters. Oil content was found to range between 71.4 and 73.9%. Oils obtained by pressing presented low acid (0.05–0.22% oleic acid), peroxide (0.05–0.47 meq O2/kg oil), K232, and K270 values, and moderate (247–365 µg/g oil) total tocopherol contents. Variations in unsaturated fatty acid contents were between 16.1 and 25.4% (oleic acid), 52.5 and 58.9% (linoleic acid), and 11.4 and 16.5% (linolenic acid). Oxidative stability (OS), as measured by the Rancimat method, was poor (2.64–3.44 h) and it correlated positively with oleic and negatively with linolenic acid contents. In contrast to their low OS, the antioxidant capacity evaluated through the 2,2‐diphenyl‐1‐picrylhydrazyl radical assay showed that the WO analyzed here have good radical‐scavenging activity. Tocopherols appear to be the most important contributors to this biochemical property. The findings connected with volatile composition showed a similar qualitative pattern where aldehydes were present at higher concentration. Most of them seem to come from unsaturated FA mainly through a chemical pathway.
Lipid damage in farmed rainbow trout (Oncorhynchus mykiss) after slaughtering and chilled storage
Authors: Ortiz Jaime , Palma Óscar , González Natalia , Aubourg Santiago P. 
Published: December 2008

AbstractThe flow ice system including ozone (OFI condition) was tested for slaughtering and storage (up to 16 days) of farmed rainbow trout (Oncorhynchus mykiss). Lipid damage analyses were carried out and compared to sensory acceptance and instrumental colour changes. Comparison to individuals processed with the flow ice system in the absence of ozone (FI condition) was undertaken. Rainbow trout slaughtered and chilled under FI and OFI conditions showed a low lipid damage development, according to lipid oxidation and hydrolysis events and lipid composition (polyunsaturated fatty acids, phospholipids and endogenous antioxidants) changes. Additionally, both icing conditions led to largely good quality and shelf life times and to the absence of changes in colour properties. It is concluded that flow ice as such, or including the presence of ozone, can be considered as ideal strategy to be employed as slaughtering and storage system during the commercialisation of the actual farmed species. The ozone presence has shown some profitable effects as leading to an extended shelf life time by quality retention of several sensory parameters; in contrast, some negligible negative effects could be observed on the secondary and tertiary lipid oxidation development. However, the oxidation values reached by individuals kept under OFI conditions cannot be considered as particularly high.
Lipidomic approaches to measuring isoprostanes and other markers of oxidative stress
Authors: Davies Sean S. 
Published: December 2008

AbstractOxidative stress shifts the normal physiological balance between the rate of formation and removal of reactive oxygen species (ROS) and leads to oxidative modification of a large number of macromolecules including lipids. Oxidative stress has been invoked as a potential mechanism in a wide variety of disease processes. One requirement for understanding the contribution of oxidative stress to disease is to quantitatively assess the resulting products during disease processes and potential interventions. ROS trigger a myriad of alterations in macromolecules, so that accurately measuring every possible alteration induced by oxidative stress is currently untenable. Therefore, quantifying specific products that are both representative of the formation of other products and that potentially directly participate in the disease process is a rational approach. This review focuses on one of the most commonly used biomarkers of oxidative stress, the F2‐isoprostanes, and then discusses the value of simultaneously measuring other related lipid peroxidation products.
Enzymatic interesterification of structured lipids containing conjugated linoleic acid with palm stearin for possible margarine production
Authors: Goli Sayed Amir Hossein , Sahri Miskandar Mat , Kadivar Mahdi 
Published: December 2008

AbstractStructured lipids containing conjugated linoleic acid as a functional ingredient were blended with palm stearin in the ratios of 30 : 70, 40 : 60, 50 : 50, 60 : 40 and 70 : 30 (wt/wt). The blends were subjected to enzymatic interesterification by Candida antarctica lipase. After interesterification of the blends, changes in the physical properties of the products, including lower melting points and solid fat contents along with different melting behaviors, were evidenced. Analysis of triacylglycerols (TAG) of the interesterified blends showed a decrease in the concentration of high‐melting TAG. X‐ray diffraction analysis revealed, that all the reacted blends were predominantly in the β' crystal form. The mixture could be used for the formulation of margarines or other, similar products.
Synthesis of α,α′‐Disubstituted Linear Ethers by an Intermolecular Nicholas Reaction – Application to the Synthesis of (+)‐cis/(–)‐trans‐Lauthisan and (+)‐cis/(+)‐trans‐Obtusan
Authors: Ortega Nuria , Martín Tomás , Martín Víctor S. 
Published: December 2008

AbstractA new and efficient methodology to prepare α,α′‐disubstituted linear ethers through an intermolecular Nicholas reaction (interNR) is described. cis‐2,8‐Disubstituted oxocanes, cis‐2,9‐disubstituted oxonanes, their trans isomers, and their parent unsaturated precursors were prepared from the corresponding Co2(CO)6–cycloalkynic ethers. Key steps in such syntheses were the ether linkage formation by interNR, RCM of the suitable acyclic dienyl ether, and montmorillonite K‐10 induced isomerization of the complexed cycloalkyne. By taking advantage of the developed methodology a short synthesis of (+)‐cis‐ and (–)‐trans‐lauthisan and (+)‐cis‐ and (+)‐trans‐obtusan are described. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Application of Tetrathiafulvalene‐Modified Carbon Nanotubes to Preparation of Integrated Mediating System for Bioelectrocatalytic Oxidation of Glucose
Authors: Kowalewska Barbara , Kulesza Pawel J. 
Published: December 2008

AbstractMultiwalled carbon nanotubes (CNTs), that are modified with ultrathin layers of tetrathiafulvalene (TTF), were demonstrated to form a stable colloidal suspension. Such dispersion was exploited to fabricate an integrated mediating system (utilizing both highly conductive carbon nanostructures, CNTs, and a redox mediator, TTF) capable of facilitating electron transfers between the active sites of the enzyme (glucose oxidase) and the electrode surface. The resulting bioelectrocatalytic system produced sizeable glucose oxidation currents in phosphate buffer solution (pH 7.0). For comparison, the system utilizing TTF‐free (bare) CNTs and the glucose oxidase enzyme showed relatively much lower activity towards the glucose oxidation. Formation, electrocatalytic reactivity, durability, and morphology of proposed bioelectrocatalytic systems were examined using cyclic voltammetry, potential step techniques, rotating disk voltammetry and transmission electron microscopy. The whole concept of the preparation of CNT‐supported redox mediating systems is of potential utility to bioelectroanalytical chemistry.
Electroreductions on Silver‐Based Electrocatalysts: The Use of Ag Nanoparticles for CHCl3 to CH4 Conversion
Authors: Rondinini S. , Aricci G. , Krpetić Ž. , Locatelli C. , Minguzzi A. , Porta F. , Vertova A. 
Published: December 2008

AbstractA preliminary investigation on a new class on electrocatalytic materials for the electroreduction of organic halides is presented and discussed. The electrocatalysts are based on silver nanoparticles (Ag_NP), ad hoc synthesised by chemical reduction of an aqueous silver salt in the presence of six different stabilising agents. The colloids are then supported on carbon powder (10% loading) for further characterisation and use. The electrocatalytic properties of the Ag_NP/carbon composites towards the dehalogenation of halocompounds are tested by cyclic voltammetry and by preparative electrolysis. The hydrodehalogenation of trichloromethane, extensively studied by this group, is selected as a model reaction, because of its relevance for the detoxification of wastes. The voltammetric characterisation is performed in an aqueous solution, supporting the composites on cavity microelectrodes. Gas‐diffusion electrodes (GDE) based on the most promising Ag_NP composite – and, for reference, on a commercial Ag/C oxygen reduction electrocatalyst – are then tested in an electrolytic process for the progressive conversion of gaseous trichloromethane to less chlorinated compounds, and ultimately to methane.
Action of Force on Rock Mass by Crack Water Pressure
Authors: Innerhofer Guntram 
Published: December 2008

AbstractThe formula of effective stress used in soil mechanics is adapted to the properties of rock mass by implementation of the wetting factor and the Saint‐Venant factor. The wetting factor defines the area over which a hydrostatic force can actually be developed, the Saint Venant factor defines the component of this force which is balanced by reduction of the effective stress in the crack zone. Here, the consequences of this concept are discussed with respect to uniaxial, plain stress and a continuum mechanical model. The effect of the concept is considered in relation to the state of stress in crack zones, and in the adjacent rock mass, and on the action of forces on the system. The development of crack propagation and of shear failure is discussed. The intention is to contribute towards a basic understanding of the complex effects of water pressure in rock masses, applicable to engineering practice.
San Francisco HEP Headrace Tunnel – TBM Success under the Presence of Pressurized Water in Faulty Deep Rock
Authors: de Oliveira Filho Afranio Alves , Belitardo Gustavo Teixeira , Büchi Ernst , Vigl Alois 
Published: December 2008

AbstractThe San Francisco Hydroelectric Project in Ecuador is utilizing hydropower from the Rio Pastaza in a 230 MW plant. 8.4 km of the 11.2 km long HRT have been excavated by a double shield (DS) TBM. After 4,950 m TBM excavation in metamorphic rock series of the Cordillera Real, the TBM was trapped by a block failure of the rock under high water ingress and the TBM shield was demolished. A rescue programme was undertaken immediately on the TBM in order to stabilize the region of the event, to get control about the water ingress, to make free and to repair the TBM and to continue excavation under controlled conditions. Concurrently an alternative rescue programme was investigated and started in order not to waste time if the rescue of the TBM should fail or if further events should occur. The TBM stoppage lasted for about five month and the rescue programme enabled the repair of the TBM and a controlled restart of the TBM without any accident. After the restart the TBM again reached a sufficient daily progress of more than 20 m/d and the tunnel could be finalized with success.
Liver damage underlying unexplained transaminase elevation in human immunodeficiency virus-1 mono-infected patients on antiretroviral therapy #
Authors: Ingiliz Patrick , Valantin Marc-Antoine , Duvivier Claudine , Medja Fadia , Dominguez Stephanie , Charlotte Frédéric , Tubiana Roland , Poynard Thierry , Katlama Christine , Lombès Anne , Benhamou Yves 
Published: December 2008

Abstract
Liver damage associated with chronic unexplained high serum transaminases in human immunodeficiency virus (HIV)-infected patients under combined antiretroviral therapy is unknown. Liver histology was prospectively investigated in patients presenting serum transaminase elevation for more than 6 months, after exclusion of alcohol abuse, hepatitis C virus (HCV) or hepatitis B virus (HBV) infection, autoimmune, and genetic liver diseases. In a subgroup of patients, liver mitochondrial activities were measured by spectrophotometry and mitochondrial DNA (mtDNA) by real-time polymerase chain reaction (PCR). Thirty patients were included with median values of alanine aminotransferase (ALT) levels: 80 U/L, age: 46 years, body mass index: 23 kg/m2, HIV RNA: 200 copies/mL, CD4 count: 365/mm3, duration of HIV infection: 13 years, and duration of treatment exposure: 118, 41, and 53 months for nucleoside reverse transcriptase inhibitors, non-nucleoside reverse transcriptase inhibitors, and protease inhibitors, respectively. Histological anomalies were found in 22 of 30 patients. Steatosis was present in 18 patients, severe in nine patients, and associated with inflammation in 16 patients with a diagnosis of non-alcoholic steatohepatitis (NASH). Fibrosis was found in 18 patients, severe in six patients and associated with steatosis in 13 patients. Significant liver respiratory complex I defect, contrasting with high complex IV activity and normal mitochondrial DNA content, was observed in the group of patients compared with controls. The presence of NASH was correlated with high fasting glycemia and insulin levels, not with liver mitochondrial function or mitochondrial DNA content. Conclusions: HIV-infected patients on combined antiretroviral therapy with chronic transaminase elevation of unknown origin have a high rate of liver lesions, mostly consistent with NASH related to insulin resistance. (Hepatology 2008.)
Non‐linearities in the relation between the exchange rate and its fundamentals
Authors: Altavilla Carlo , De Grauwe Paul 
Published: December 2008

AbstractWe develop a simple theoretical model in which chartists and fundamentalists interact. The model predicts the existence of different regimes, and thus non‐linearities in the link between the exchange rate and its fundamentals. We test the model empirically by adopting a Markov‐switching vector error correction model. The results suggest the presence of non‐linear mean reversion in the nominal exchange rate process. The implications are that different sets of macroeconomic fundamentals act as driving forces of the exchange rates during different time periods. Copyright © 2008 John Wiley & Sons, Ltd.
Light‐Nutrient Influences on Biomass, Photosynthetic Potential and Composition of Suspended Algal Assemblages in the Middle Cape Fear River, USA
Authors: Dubbs Lindsay L. , Whalen Stephen C. 
Published: December 2008

AbstractDilution bioassays were conducted to evaluate the impact of nutrients on biomass (chlorophyll a), photosynthetic potential, and class composition of suspended algal assemblages in the middle Cape Fear River (USA). Ambient concentrations of dissolved inorganic nitrogen (DIN) and soluble reactive phosphorus (SRP) varied from 37.2 to 83.8 and from 1.0 to 7.1 μmol L–1. Experiments conducted at photosynthetic photon flux densities (PPFDs) similar to the mixed water column (< 1 to 5.3 E m–2d–1) showed no change in chlorophyll a, photosynthetic potential, or algal class composition at 15, 30, and 45% dilutions of DIN, SRP, or both. However, chlorophyll a and photosynthetic potential increased significantly in nutrient dilution bioassays conducted at PPFDs four‐fold above ambient, while the abundance of diatoms and Chrysophytes increased under elevated PPFD and ambient or elevated nutrients. Overall, the data indicate that irradiance is more important than nutrients in determining the size and class composition of suspended algal assemblages. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fiber technology for reliable repair of skeletal muscle
Authors: Franklin J. E. , Marler J. J. , Byrne M. T. , Melvin A. J. , Clarson S. J. , Melvin D. B. 
Published: December 2008

AbstractConventional soft‐tissue reclosure methods—sutures and staples—require substantial organized‐collagen content. Some tissues lack extensive intrinsic collagenous content. Wound disruption consequences range from newly closed abdominal wounds bursting open, to post‐cesarean wombs splitting at delivery, to heart valves loosening. Although sutures do approach the theoretical limit of normal force transfer‐cross‐sectional area times compressive strength, a different paradigm‐shear force transfer across the far greater surface attainable by fine fibers parallel to the potential disruptive force could exceed that theoretical limit. Capacity is now the product of frictional coefficient, existing tissue pressure, and contact area. Using a device comprising bundles of poly(ethylene terephthalate) fibers through tissue, we previously coupled muscles to devices and bones. Here we tested an analogous device for reclosing fascia‐stripped abdominal wall muscles. In 28 rabbits, fascia‐deprived rectus abdominus muscles were reclosed, using the experimental device or conventional sutures. Testing muscles from the 21 three‐week survivors, (with closure devices retained‐the usual clinical practice) demonstrated experimental failure strength which exceeded that of controls by 58%. Histologically, solid tissue elements did in‐grow between fibers for an extensive tissue‐prosthetic interface. Both histology and mechanical performance suggest the fiber technology presented herein surpasses conventional sutures in closure of collagen‐deficient tissues. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
A dissolution‐diffusion model for the TAXUS™ drug‐eluting stent with surface burst estimated from continuum percolation
Authors: Barocas Victor , Drasler William , Girton Tim , Guler Ismail , Knapp David , Moeller Jeff , Parsonage Edward 
Published: December 2008

AbstractA two‐layer dissolution‐diffusion model is derived which incorporates a surface burst component that is estimated from continuum percolation models of overlapping Poisson distributed spheres. The model is shown to adequately describe the release properties of paclitaxel from a hydrophobic polymer matrix, including the surface burst and sustained release dependence on drug loading. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009
The influence of thermal treatment on the mechanical characteristics of a PLLA coiled stent
Authors: Welch Tré R. , Eberhart Robert C. , Chuong Cheng‐Jen 
Published: December 2008

AbstractWe studied the effects of thermal treatment on the expansive characteristics of a coil‐within‐coil Poly(L‐lactic acid) (PLLA) fiber stent developed at our institution to improve its mechanical performance and reproducibility. Following fabrication, furled stents were thermally treated at 62°C for 25 min. The mechanical characteristics were measured compared with those of untreated stents when both were expanded via sequential balloon catheter pressure loading up to 12 atm. Treated stents reached full diameter at 3 atm and maintained that diameter despite further pressure increases. Using measurements of pressure, diameter, and axial length, we calculated the sequential mechanical work required to unfurl the stent. The mechanical work for complete unfurling of treated stents was significantly less than that required for untreated controls. Little axial dimensional change was observed for treated stents. Treated stents exhibited higher stiffness than controls at all pressure levels and also demonstrated higher resistance to external pressure‐induced collapse, as measured in a special apparatus developed in our laboratory. Differential scanning calorimetry measurements indicated higher crystallinity values for fibers used in treated stents compared with controls. SEM examination of striations revealed that treated stents underwent less twist than controls following balloon‐induced unfurling. The results indicate that, thermal treatment improves the reorientation and realignment of fiber crystalline structure, and favorably influences on the fiber stress‐strain behavior and the expansive mechanical characteristics of the PLLA fiber stents. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009