bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative study on the stability of crude and refined rice bran oil during long‐term storage at room temperature
Authors: Mezouari Samia , Eichner Karl 
Published: March 2007

AbstractThe effect of the full refining process on the stability of rice bran oil during storage at room temperature was studied. Crude and refined rice bran oil were kept in the dark and were exposed to light for 240 days, and every 10 days samples were drawn and analysed. The storage stability of crude and fully refined rice bran oil was determined and compared with respect to fatty acid composition, tocopherols, tocotrienols, sterols and γ‐oryzanol content. In addition, the oxidative status was evaluated by determining the concentration of polar compounds and the oil stability index (OSI). A good correlation between the decrease of total tocopherols and the OSI was found. α‐Tocopherol had the highest correlation coefficient (r2 = 0.9653) in crude rice bran oil kept in the dark, and γ‐tocopherol showed the lowest in the refined sample (r2 = 0.4722). The order of stability of tocopherols and tocotrienols in crude oil was completely different from that in refined oil. In comparison to tocopherols, sterols showed a better stability during the entire storage period. The exposure to daylight heavily affected the composition and the stability of both crude and refined rice bran oil.
Alternate oils in fish feeds
Authors: Pickova Jana , Mørkøre Turid 
Published: March 2007

AbstractNearly half of the fish consumed as food worldwide are raised on fish farms rather than caught in the wild, as shown by FAO statistics. The increasing aquaculture of predatory carnivorous fish demands new sources of feed constituents, particularly oils at the moment. Common terrestrial plant oils contain only traces of the long‐chain polyunsaturated fatty acids. In connection with fish feed, especially the lack of n‐3 “marine fatty acids” is obvious. Recommendations on the required amounts of the fatty acids DHA (22:6n‐3) and EPA (20:5n‐3) exist from 1994. When plant oil‐based diets are fed during the growing phase and replaced by a fish oil‐based diet during a period prior to slaughter, most of the beneficial lipid composition of fish in terms of human dietary recommendations is restored. Little attention has been focused on the fish welfare in connection to substitution of dietary oil sources, and studies are still scarce. New fish diets will rely heavily on the use of alternate ingredients such as plant oils also for carnivorous cold‐temperate water fish species. In the future, an addition of synthetic or GMO‐produced “marine” fatty acids is a possible scenario. The aim of this review is to highlight some plant oils used in fish feeds, with special emphasis on compounds other than fatty acids. We also include some results from an ongoing study, where the effect of dietary soy oil on gonad maturation in Atlantic cod (Gadus morhua) is indicated.
The effect of polymers and surfactants on the pour point of palm oil methyl esters
Authors: Sern Cheah Han , May Choo Yuen , Zakaria Zuriati , Daik Rusli , Foon Cheng Sit 
Published: March 2007

AbstractThe objective of this research was to find some additives suitable to reduce the pour point (PP) of palm oil methyl esters. The PP properties of palm oil methyl esters (biodiesel) were evaluated with commercially available polymeric and surfactant compounds with various polarities, molecular sizes and structures. The compounds under study were poly(ethylene glycol), poly(methyl methacrylate), poly(ethylene‐co‐vinyl acetate), poly(styrene‐co‐maleic anhydride), poly(ethylene glycol) distearate, poly‐(octadecyl methacrylate), poly(1‐decene), poly(maleic anhydride‐alt‐1‐octadecene), caprylic acid sodium salt, N‐lauroylsarcosine sodium salt, polyoxyethylene(2) cetyl ether and polyoxyethylene(10) cetyl ether. Seven out of the twelve polymeric compounds tested were miscible in palm oil methyl esters due to similar polarities of the solute and biodiesel. The blends of the resultant seven polymeric compounds in palm oil methyl esters were evaluated respectively for their effect on the PP property. Poly‐(maleic anhydride‐alt‐1‐octadecene) was able to improve the PP of palm oil methyl esters from 12 to 6 °C when 2 wt‐% was added. The cloud point was reduced from 12.9 to 8.1 °C, and the cold filter plugging point was reduced from 12 to 7 °C, whilst the flash point value remained unchanged at 156 °C when 2 wt‐% of poly(maleic anhydride‐alt‐1‐octadecene) was added to the palm oil methyl esters.
Zeolite‐catalyzed isomerization of oleic acid to branched‐chain isomers
Authors: Ngo Helen L. , Nuñez Alberto , Lin Wenbin , Foglia Thomas A. 
Published: March 2007

AbstractBranched‐chain (bc) saturated fatty acids (SFA) have potential as oleochemical intermediates since they have better oxidative stability than linear unsaturated fatty acids (UFA) and have better low‐temperature properties than linear SFA. Previous studies in converting UFA to bc‐FA using clay catalysts have resulted in only modest yields and conversions. Recent reports, however, have suggested that certain zeolites can be effective catalysts for converting UFA to bc‐FA in higher yields and conversions. In this work, we examined the scope and potential of the zeolite‐catalyzed synthesis of bc‐FA starting from readily available monounsaturated linear FA. Our results show that common UFA such as oleic acid can be converted to bc‐isomers using modified Ferrierite zeolite catalysts with high conversions (98%) and high selectivity (85%) and that the zeolite catalysts are reusable for at least three cycles. The positions of branching (methyl) on the FA chain were determined from the GC‐MS spectra of the picolinyl esters of the bc‐FA.
Analytical characteristics of crude and refined palm oil and fractions
Authors: Gee Ping Tou 
Published: March 2007

AbstractPalm oil provides significantly higher amounts of oil/ha than any other commercial oil crop. Palm oil can be physically refined and fractionated into various fractions, ranging from very hard palm stearin with iodine values below 10 to palm superolein with iodine values as high as 72. Palm mid fractions consisting of symmetrical triacylglycerols provide sharp‐melting fats for niche applications. The wide range of palm oil fractions provides versatility for different food applications, with the additional advantage that natural palm oil is trans free and genetic modification free. Palm oil and its fractions are widely used for direct blending with other oils or are interesterified with other oils to meet the trans‐free fat requirements of the food industry. The sn‐2 position of palm oil triacylglycerols is mainly esterified with oleic and linoleic acid. This provides better bioavailability of oleic acid as monounsaturated fatty acid and linoleic acid as an essential fatty acid, as compared to oils or fats with similar composition but with randomized fatty acid distribution. Crude palm oil also contains highly valuable minor components, including carotenoids and tocotrienols, which are potent fat‐soluble antioxidants. Recent research findings on potential chemo‐preventive and chemotherapeutic roles of tocotrienols are extremely encouraging.
Semipermanent capillary coatings in mixed organic–water solvents for CE
Authors: Diress Abebaw G. , Yassine Mahmoud M. , Lucy Charles A. 
Published: March 2007

AbstractThis report describes the creation of semipermanent capillary coatings that are compatible with organic–water solvent systems in CE. The coatings are created by simply rinsing the fused‐silica capillary with long double‐chain cationic surfactants, such as dimethyl‐ditetradecyl ammonium bromide (2C14DAB), dihexadecyldimethyl ammonium bromide (2C16DAB), and dimethyldioctadecyl ammonium bromide (2C18DAB). These surfactants generate semipermanent bilayer coatings on the capillary surface, which display a high degree of stability in buffers containing up to 60% v/v of organic solvents, such as methanol and ACN. The coating stability increases with increasing hydrophobicity of the surfactant, i.e., with increasing chain length. For instance, the EOF changes by only 1.2% in a 2C18DAB‐coated capillary after 130 capillary volumes of rinsing with 60% v/v methanol containing buffer. The bilayer coatings allow separations to be performed without the need to regenerate the coating between runs or to maintain the EOF modifier in the run buffer. Rapid separations (<2 min) of anions and basic drugs with migration time reproducibility of less than 0.5% RSD and efficiencies of 0.4–0.6 million plates/m are obtained. In addition, selectivity changes for small anions and cationic drugs are also observed when the organic solvent content is adjusted.
Short‐column CE coupled with inductively coupled plasma MS for high‐throughput speciation analysis of chromium
Authors: Li Bao‐Hui , Yan Xiu‐Ping 
Published: March 2007

AbstractA method was developed for high‐throughput speciation analysis of chromium by on‐line coupling of short‐column capillary electrophoresis (SC‐CE) and inductively coupled plasma mass spectrometry (ICP‐MS). Baseline separation of Cr(III) and Cr(VI) was achieved within 1 min by SC‐CE in a 15 cm×75 μm id fused‐silica capillary at 6 kV using 15 mM HNO3 as running electrolyte. The precisions (RSD, n = 5) of migration time and peak area for Cr(III) and Cr(VI) were in the range of 1.8–2.4% and 2.2–5.7%, respectively. The limits of detection (3σ) of Cr(III) and Cr(VI) were 1.8 and 1.9 μg/L, respectively. The synthesized samples containing Cr(III) and Cr(VI) species were determined by the developed SC‐CE‐ICP‐MS hyphenated technique, and the recoveries of Cr(III) and Cr(VI) in the synthesized samples were in the range of 103–110% and 90–108%, respectively.
On‐line preparation of microsamples prior to CE
Authors: Capote Feliciano Priego , de Castro María Dolores Luque 
Published: March 2007

AbstractAn experimental setup is presented here for the automated analysis of microsamples, based on the on‐line coupling of a capillary SPE module and a CE unit using a two‐position six‐port valve, an open–closed valve to isolate electrically the sample preparation from the CE unit and a “T” interface. A C18 trapping microcolumn (dimensions 2.5 cm×100 μm id×360 μm od) was used for the SPE step. The utility of the proposed experimental setup was demonstrated by applying it to the determination of quinolone antibiotics in serum microsamples, which was efficiently carried out in less than 20 min (4 min for protein denaturation and 15 min for analytes preconcentration and CE‐UV separation‐determination). A complete optimization study was performed for preconcentration and cleanup of quinolones, the coupling of sample preparation module to the CE unit and electrophoretic separation of quinolones. A preconcentration factor of 10.4 was achieved. The volume injected with the proposed method was 125 nL versus 160 nL introduced by hydrodynamic injection. The volume required for the analysis was 2 μL, which makes the proposed experimental setup very useful for the analysis of microsamples in fields of current interest such as metabolomics or proteomics.
Carbon nanotube detectors for microchip CE: Comparative study of single‐wall and multiwall carbon nanotube, and graphite powder films on glassy carbon, gold, and platinum electrode surfaces
Authors: Pumera Martin , Merkoçi Arben , Alegret Salvador 
Published: March 2007

AbstractThe performance of microchip electrophoresis/electrochemistry system with carbon nanotube (CNT) film electrodes was studied. Electrocatalytic activities of different carbon materials (single‐wall CNT (SWCNT), multiwall CNT (MWCNT), carbon powder) cast on different electrode substrates (glassy carbon (GC), gold, and platinum) were compared in a microfluidic setup and their performance as microchip electrochemical detectors was assessed. An MWCNT film on a GC electrode shows electrocatalytic effect toward oxidation of dopamine (E1/2 shift of 0.09 V) and catechol (E1/2 shift of 0.19 V) when compared to a bare GC electrode, while other CNT/carbon powder films on the GC electrode display negligible effects. Modification of a gold electrode by graphite powder results in a strong electrocatalytic effect toward oxidation of dopamine and catechol (E1/2 shift of 0.14 and 0.11 V, respectively). A significant shift of the half‐wave potentials to lower values also provide the MWCNT film (E1/2 shift of 0.08 and 0.08 V for dopamine and catechol, respectively) and the SWCNT film (E1/2 shift of 0.10 V for catechol) when compared to a bare gold electrode. A microfluidic device with a CNT film‐modified detection electrode displays greatly improved separation resolution (Rs) by a factor of two compared to a bare electrode, reflecting the electrocatalytic activity of CNT.
Elevated frequencies of micronucleated erythrocytes in infants exposed to zidovudine in utero and postpartum to prevent mother‐to‐child transmission of HIV
Authors: Witt Kristine L. , Cunningham Coleen K. , Patterson Kristine B. , Kissling Grace E. , Dertinger Stephen D. , Livingston Elizabeth , Bishop Jack B. 
Published: March 2007

AbstractZidovudine‐based antiretroviral therapies (ARTs) for treatment of HIV‐infected pregnant women have markedly reduced mother‐to‐child transmission of the human immunodeficiency virus (HIV‐1) from ∼25% to <1%. However, zidovudine (ZDV; AZT), a nucleoside analogue, induces chromosomal damage, gene mutations, and cancer in animals following direct or transplacental exposure. To determine if chromosomal damage is induced by ZDV in infants exposed transplacentally, we evaluated micronucleated reticulocyte frequencies (%MN‐RET) in 16 HIV‐infected ART‐treated mother–infant pairs. Thirteen women received prenatal ART containing ZDV; three received ART without ZDV. All infants received ZDV for 6 weeks postpartum. Venous blood was obtained from women at delivery and from infants at 1–3 days, 4–6 weeks, and 4–6 months of life; cord blood was collected immediately after delivery. Ten cord blood samples (controls) were obtained from infants of HIV‐uninfected women who did not receive ART. %MN‐RET was measured using a single laser 3‐color flow cytometric system. Tenfold increases in %MN‐RET were seen in women and infants who received ZDV‐containing ART prenatally; no increases were detected in three women and infants who received prenatal ART without ZDV. Specifically, mean %MN‐RET in cord blood of ZDV‐exposed infants was 1.67 ± 0.34 compared with 0.16 ± 0.06 in non‐ZDV ART‐exposed infants (P = 0.006) and 0.12 ± 0.02 in control cord bloods (P < 0.0001). %MN‐RET in ZDV‐exposed newborns decreased over the first 6 months of life to levels comparable to cord blood controls. These results demonstrate that transplacentalZDV exposure is genotoxic in humans. Long‐term monitoring of HIV‐uninfected ZDV‐exposed infants isrecommended to ensure their continued health. Environ. Mol. Mutagen. Published 2007 Wiley‐Liss, Inc.
Genotoxicity assessed by the comet and GPA assays following in vitro exposure of human lymphoblastoid cells (H9) or perinatal exposure of mother–child pairs to AZT or AZT‐3TC
Authors: Escobar Patricia A. , Olivero Ofelia A. , Wade Nancy A. , Abrams Elaine J. , Nesel Carol J. , Ness Roberta B. , Day Richard D. , Day Billy W. , Meng Quanxin , O'Neill J. Patrick , Walker Dale M. , Poirier Miriam C. , Walker Vernon E. , Bigbee William L. ,   for the Study Team
Published: March 2007

AbstractThe genotoxicity of zidovudine (AZT) based treatments was investigated in human H9 lymphoblastoid cells in an in vitro study and in red blood cells (RBCs) from perinatally exposed HIV‐1‐infected mothers and their infants in an observational cohort study. Exposure of H9 cells for 24 hr to AZT produced dose‐dependent increases in Comet assay tail moment (TM) when electrophoresed at pH 13.0, but not at pH 12.1 or pH 8.0, suggesting that DNA damage was via alkali‐labile lesions and not double‐stranded DNA strand breaks. The TM dose response at pH 13.0 correlated directly with AZT‐DNA incorporation determined by AZT‐radioimmunoassay. Levels of DNA damage in utero, measured by Comet assay TM, were similar in cord blood mononuclear cells of nucleoside analog‐exposed newborns (n = 43) and unexposed controls (n = 40). In contrast, the glycophorin A (GPA) somatic cell mutation assay (which screens for large‐scale DNA damage in RBCs) showed clear evidence that GPA N/N variants, arising from chromosome loss and duplication, somatic recombination, and gene conversion, were significantly elevated in mother–child pairs receiving prepartum AZT plus lamivudine (3TC). Cord blood from newborns exposed to AZT‐3TC had GPA N/N variant frequencies of 4.7 ± 0.7 (mean ± SE) × 10−6 RBCs (n = 26 infants) compared with 2.2 ± 0.3 × 10−6 RBCs for unexposed controls (n = 30 infants; P < 0.001). Elevations in GPA N/N variants generally persisted through 1 year of age in nucleoside analog‐exposed children. Overall, the mutagenic effects found in mother–child pairs receiving AZT‐based treatments justify their surveillance for long‐term genotoxic consequences. Environ. Mol. Mutagen., 2007. © 2007 Wiley‐Liss, Inc.
Transplacental carcinogenicity of 3′‐azido‐3′‐deoxythymidine in B6C3F1 mice and F344 rats
Authors: Walker Dale M. , Malarkey David E. , Seilkop Steven K. , Ruecker Frederick A. , Funk Kathleen A. , Wolfe Marilyn J. , Treanor Christopher P. , Foley Julie F. , Hahn Fletcher F. , Hardisty Jerry F. , Walker Vernon E. 
Published: March 2007

AbstractThe prophylactic use of zidovudine (3′‐azido‐3′‐deoxythymidine, AZT) during pregnancy greatly reduces transmission of HIV‐1 from infected mothers to their infants; however, the affinity of host cell DNA polymerases for AZT also allows for its incorporation into host cell DNA, predisposing to cancer development. To expand upon previous transplacental carcinogenesis assays performed in CD‐1 mice, the transplacental carcinogenicity of AZT was evaluated in a second mouse strain and a second rodent species. Date‐mated female mice and rats were gavaged daily with 0, 80, 240, or 480 mg AZT/kg bw during the last 7 days of gestation. At 2 years postpartum, male and female B6C3F1 mouse and F344 rat offspring (n = 44–46 of each sex and species/treatment group) were necropsied for gross and microscopic tissue examinations. Under the conditions of these two‐year studies, there was clear evidence of carcinogenic activity based upon significant dose‐related trends and increases in the incidences of hemangiosarcoma in male mice and mononuclear cell leukemia in female rats. There was some evidence of carcinogenic activity in the livers of male mice based upon a positive trend and an increased incidence of hepatic carcinoma in the high‐dose AZT group. The incidence of gliomas in female rats exceeded the historical background rates for gliomas in F344 rats. P53 overexpression was detected in some AZT‐treated mouse neoplasms. These and other cancer‐related findings confirm and extend those of previous transplacental carcinogenicity studies of AZT in mice, support the need for long‐term follow‐up of nucleoside reverse transcriptase inhibitor (NRTI)‐exposed children, and indicate the necessity for effective protective strategies against NRTI‐induced side effects. Environ. Mol. Mutagen., 2007. © 2007 Wiley‐Liss, Inc.
Dynamic response of the KII building to the San Fernando earthquake
Authors: Muto Kiyoshi 
Published: March 2007

AbstractThe KII Building was subjected to the San Fernando earthquake on 9 February 1971 without suffering any damage. During the earthquake, strong motion accelerations were recorded at the base, middle and top of the building.The simulation analysis of the building was carried out taking into account the interaction between the building and the soil. The internal viscous damping theory considering the different damping coefficients for the building and the soil was adopted.Comparison of the calculated and observed acceleration time histories as well as the floor response spectra showed satisfactory agreement. On the basis of the response spectrum values, the fact that no damage was observed in this building is justified theoretically.
Response of offshore towers to strong motion earthquakes
Authors: Penzien J. , Kaul M. K. 
Published: March 2007

AbstractPresented is a stochastic method of analysis of offshore towers subjected to strong motion earthquakes. A zero mean ergodic Gaussian process of finite duration is used to characterize horizontal ground acceleration and full fluid structure interaction effects are included. Numerical results for four representative deep water towers having heights of 475, 675, 875 and 1075 ft are compared with corresponding results obtained by the response spectrum method of analysis. Particular emphasis is placed on the maximum or extreme values of total transverse shear and total overturning moment. Comparisons are made with code values and the role of ductility is briefly discussed.
Forced vibration of a tall steel‐frame building
Authors: Jennings P. C. , Matthiesen R. B. , Brent Hoerner J. 
Published: March 2007

AbstractThe dynamic properties of the twenty‐two‐story, steel‐frame San Diego Gas and Electric Company Building in San Diego, California, have been determined experimentally in a series of co‐operative tests between the California Institute of Technology and the University of California at Los Angeles. The building was vibrated by two eccentric mass exciters capable of frequencies up to 10 c/sec and forces as much as 5000 Ib each. The natural frequencies, associated mode shapes and the amounts of damping were determined for the first six modes of vibration in each of the two translational directions, and also in torsion. The mode shapes and frequencies showed, in general, the regularity and uniformity that appears typical of many tall buildings, but the three fundamental modes (nominally NS, EW and torsion) of the structure showed a coupling of translational and rotational components to a degree that was unexpected in a building whose structural frame is essentially symmetric. It is believed that this may be a consequence of the exceptionally small differences among the three fundamental frequencies. The damping in the first eighteen modes of the structure varied from 1.6 to 4.4 per cent, with a slight tendency for the larger values to be associated with the higher modes. Of the simpler damping models that might be used for analysis of the building, constant modal damping appears most appropriate and stiffness or mass proportional damping would not be realistic.
Comparisons between ambient and forced vibration experiments
Authors: Trifunac Mihailo D. 
Published: March 2007

AbstractThe ambient and forced vibration techniques for testing full‐scale structures are critically compared. Both methods, based on small level excitation, may be used to determine many mode shapes and frequencies of vibration and the corresponding damping values, with adequate accuracy for most purposes. The two techniques give mutually consistent results.The mode amplitudes determined by ambient and forced vibration tests show systematic departure for high modes and near the top levels of buildings tested. This phenomenon is attributed to the participation of all mode shapes and is a consequence of excitation by a concentrated force near the top of a building and at a frequency differing by only a few per cent from a natural frequency of vibrations.A new way of showing the effect of unwanted modes on the response near resonance of the mode being sought is developed. It is particularly useful for the analysis of steady, forced vibration tests of structures using eccentric mass vibration generators.