bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorocarbon‐hydrocarbon interactions in interfacial and micellar systems
Authors: Mukerjee P. 
Published: June 2007

AbstractThe interactions of fluorocarbons and hydrocarbons in liquid mixtures are known to be highly nonideal. Recent research has indicated that the unusual characteristics of such interactions have a significant influence on the behavior of many interfacial and micellar systems in which such interactions occur. Results from several different studies are presented. These involve (a) properties of partially fluorinated surfactants and lipids, including comments on the use of fluorine substituted groups as spectroscopic probes; (b) surface tensions of nonideal mixtures of liquid fluorocarbons and hydrocarbons and their interfacial tensions against water; (c) adsorptions of fluorocarbon and hydrocarbon surfactants to air/water, hexane/water, and perfluorohexane/water interfaces and a comparison of relative affinities; (d) formation of mixed micelles of fluorocarbon and hydrocarbon surfactants and evidence of partial miscibility of micelles; (e) comparison of adsorption of fluorocarbon and hydrocarbon surfactants to graphon; and (f) comparison of wetting of hydrocarbon‐like solids by aqueous solutions of fluorocarbon and hydrocarbon surfactants.
A new twin‐screw press design for oil extraction of dehulled sunflower seeds
Authors: Isobe S. , Zuber F. , Uemura K. , Noguchi A. 
Published: June 2007

Transport of material in a single‐screw press depends mainly on friction between the material and the barrel’s inner surface and the screw surface during screw rotation. Thus, a solid core component, like seed hulls, is often necessary to produce the fraction. This sometimes causes excess frictional heat, large energy consumption and oil deterioration. Furthermore, if single‐screw presses are not configured with breaker bars or other special equipment, they provide inadequate crushing and mixing.A twin‐screw oil press can be expected to solve these problems because of the higher transportation force, similar to a gear pump, and better mixing and crushing at the twin‐screw interface. A twin‐screw press (screw diameter=136 mm, length/diameter=6.5, screw speed 15–100 rpm, feed rate=50–150 kg/h) was designed with partially intermeshing and counter‐rotating screws and was tested on dehulled sunflower seed. The results were compared to a single‐screw lab‐scale press. Dehulled sun‐flower seed (wt, 6.0%; oil, 58.6%) without pretreatments (crushing or cooking) gave 93.6% oil recovery with the twin‐screw press, in contrast to 20% oil recovery with the single‐screw press. The oil expressed with a twin‐screw press had less foreign material than the oil from the single‐screw press. Other properties of the oil were also good. Energy consumption of the twin‐screw press was more efficient. All results suggested that oil production from dehulled sunflower seed with a twin‐screw press is highly efficient.
Measurement of oxidation in dried milk products with thiobarbituric acid
Authors: Sidwell C. G. , Salwin Harold , Mitchell J. H. 
Published: June 2007

SummarySteam‐distillation of dry whole milk was found to be an effective means of separating the products of fat oxidation preparatory to reacting them with 2‐thiobarbituric acid (TBA). The milk powder samples were reconstituted and acidified prior to steam distillation. A fraction of the distillate was reacted with the reagent to produce the red‐colored product, which was then estimated spectrophotometrically at 530 mμ. Factors which influence the sensitivity and reliability of the method were investigated. The method is rapid and reproducible, and the test solutions are free of turbidity. The reaction is a measure of the oxidation of dry whole milk, and when it was applied to samples from storage, the results had validity in terms of flavor.
Role of Hyperbaric Oxygen Therapy in the Treatment of Postoperative Organ/Space Sternal Surgical Site Infections
Authors: Barili Fabio , Polvani Gianluca , Topkara Veli K. , Dainese Luca , Cheema Faisal H. , Roberto Maurizio , Naliato Moreno , Parolari Alessandro , Alamanni Francesco , Biglioli Paolo 
Published: June 2007

AbstractBackgroundA prospective trial was designed to evaluate the effect of hyperbaric oxygen (HBO) therapy on organ/space sternal surgical site infections (SSIs) following cardiac surgery that requires sternotomy.MethodsA total of 32 patients who developed postoperative organ/space sternal SSI were enrolled in this study from 1999 through 2005. All patients were offered HBO therapy. Group 1 included the patients who accepted and were able to undergo HBO therapy (n = 14); group 2 included patients who refused HBO therapy or had contraindications to it (n = 18).ResultsThe two groups were well matched at baseline with comparable preoperative clinical characteristics and operative factors. Staphylococcus was the most common pathogen for both groups. The duration of infection was similar in groups 1 and 2 (31.8 7.6 vs. 29.3 5.7 days, respectively, p = 0.357). The infection relapse rate was significantly lower in group 1 (0% vs. 33.3%, p = 0.024). Moreover, the duration of intravenous antibiotic use (47.8 ± 7.4 vs. 67.6 ± 25.1 days, p = 0.036) and total hospital stay (52.6 ± 9.1 vs. 73.6 ± 24.5 days, p = 0.026) were both significantly shorter in group 1.ConclusionHyperbaric oxygen is a valuable addition to the armamentarium available to physicians for treating postoperative organ/space sternal SSI.
Pyrrolidine Dithiocarbamate Reduces Lung Injury Caused by Mesenteric Ischemia/Reperfusion in a Rat Model
Authors: Kabay Burhan , Teke Zafer , Aytekin Faruk Onder , Yenisey Cigdem , Bir Ferda , Sacar Mustafa , Erdem Ergun , Ozden Akin 
Published: June 2007

AbstractBackgroundPyrrolidine dithiocarbamate (PDTC) is a low‐molecular thiol antioxidant and potent inhibitor of nuclear factor‐κB (NF‐κB) activation. It has been shown to attenuate local harmful effects of ischemia/reperfusion (I/R) injury in many organs. In this study, we aimed to study the effect of PDTC on lung reperfusion injury induced by superior mesenteric occlusion.MethodsMale Wistar‐albino rats randomized into three groups: (1) sham‐operated control group (n = 12), laparotomy without I/R injury; (2) intestinal ischemia/reperfusion (I/R) group (n = 12), 60 min of ischemia by superior mesenteric occlusion followed by 2 h of reperfusion; and (3) I/R+PDTC‐treated group (n = 12), 100 mg/kg injection of PDTC intravenously, 30 min after the commencement of reperfusion. Evans blue dye was injected to half of rats in all groups before the induction of I/R. We assessed the degree of pulmonary tissue injury biochemically by measuring malondialdehyde (MDA), glutathione (GSH), and nitric oxide (NO) levels, and histopathologically by establishing pulmonary neutrophil sequestration and acute lung injury scoring. Pulmonary edema was evaluated by Evans blue dye extravasation, as well as lung tissue wet/dry weight ratios.ResultsPyrrolidine dithiocarbamate treatment significantly reduced the MDA and NO levels, and increased the GSH levels in the lung parenchyma, biochemically (p < 0.05), and atteneuated the pulmonary parenchymal damage, histopathologically (p < 0.05). However, pulmonary neutrophil sequestration was not affected by postischemic treatment with PDTC (p > 0.05). Pyrrolidine dithiocarbamate administration also significantly alleviated the formation of pulmonary edema, as evidenced by the decreased Evans blue dye extravasation and organ wet/dry weight ratios (p < 0.05).ConclusionsThis study showed that postischemic treatment with PDTC significantly attenuated the lung reperfusion injury. Further clinical studies are needed for better understanding of the specific mechanisms of PDTC protection against I/R‐related organ injury and to clarify whether PDTC may be a useful therapeutic agent during particular operations where remote organ I/R injury occurs.
Perioperative Vasopressors Are Associated with an Increased Risk of Gastrointestinal Anastomotic Leakage
Authors: Zakrison Tanya , Nascimento Bartolomeu A. , Tremblay Lorraine N. , Kiss Alex , Rizoli Sandro B. 
Published: June 2007

AbstractBackgroundThe purpose of this study was to investigate the effect of vasopressors on gastrointestinal (GI) anastomotic leaks. Vasopressors are commonly used in surgical patients admitted to the intensive care unit (ICU) and their effects on GI anastomotic integrity are unknown.Patients and MethodsSurgical patients admitted to the ICU in our tertiary university hospital following the creation of a GI anastomosis were studied by a retrospective chart analysis for anastomotic leaks and complicationsResultsA total of 223 patients with 259 GI anastomoses, mostly for cancer, were admitted to the ICU immediately after surgery. Twenty‐two patients developed anastomotic leaks (9.9%). The two groups (leak versus no‐leak) had similar demographics, surgery type and indication, type of anastomosis, co‐morbidities, cancer, steroid use, blood transfusion, drains, and epidural catheters. Vasopressor use was associated with increased anastomotic leakage (p = 0.02, OR 3.25). Multiple vasopressors and prolonged exposure caused even higher leaking rates. This effect was independent of the medical status and operative morbidity (APACHE II, POSSUM). Blood pressure preceding vasopressor use was similar in both groups. Vasopressors might have been occasionally used to treat hypovolemia. Patients with leaks had higher reoperation rates (41% versus 1%, p < 0.0001) and mortality (21% versus 4%, p = 0.002).ConclusionsVasopressors appear to increase anastomotic leaks threefold, independent of clinical/surgical status or hypotension. Evidence‐based guidelines are warranted for the optimal use of vasopressors in postoperative patients admitted to the ICU.
Postoperative Liver Dysfunction and Future Remnant Liver: Where Is the Limit?
Authors: Ferrero Alessandro , Viganò Luca , Polastri Roberto , Muratore Andrea , Eminefendic Haris , Regge Daniele , Capussotti Lorenzo 
Published: June 2007

AbstractBackgroundThe future remnant liver (FRL) limit for safe major hepatectomy with low risk of postoperative liver failure has not yet been well defined.MethodsBetween April 2000 and September 2004, every patient scheduled for major hepatectomy in our institution underwent CT‐volumetry of FRL. Patients with FRL <25% underwent portal vein embolization (PVE). Exclusion criteria were PVE, associated vascular resection and liver cirrhosis. The FRL was correlated with short‐term results in patients with normal liver (group A) and those with impaired liver function secondary to neoadjuvant chemotherapy or cholestasis (bilirubin >2 mg/100 ml) (group B). Liver dysfunction was defined as both PT <50% and serum bilirubin level >5 mg/100 ml for three or more consecutive days.ResultsA total of 119 patients were analyzed, 72 in group A and 47 in group B. The FRL value was the only significant risk factor for postoperative liver dysfunction in the univariate and multivariate analysis (p = 0.009). The FRL did not correlate with postoperative mortality and morbidity. Bilirubin and prothrombin time (PT) on days 3 and 7 were significantly correlated to FRL in both groups. In group A, patients with postoperative liver dysfunction had a FRL<30% (3 versus 0; p = 0.005). According to receiving operator characteristic (ROC) curve analysis, a FRL value of 26.5% predicted postoperative liver dysfunction with 66.7% sensitivity, 97.1% specificity, 50% positive predictive value (PPV), and 98.5% negative predictive value (NPV). In group B, patients with postoperative liver dysfunction had a FRL <35% (4 versus 0; p = 0.027). According to ROC curve analysis, a FRL value of 31.05% predicted postoperative liver dysfunction with 75% sensitivity, 79.1% specificity, 25% PPV, and 97.1% NPV.ConclusionsHepatectomy can be considered safe when FRL is >26.5% in patients with healthy liver and >31% in patients with impaired liver function.
Incorporation of Arachidonic and Stearic Acids Bound to L‐FABP into Nuclear and Endonuclear Lipids from Rat Liver Cells
Authors: Maté Sabina M. , Layerenza Juan P. , Ves‐Losada Ana 
Published: June 2007

AbstractThe incorporation of exogenous fatty acids bound to L‐FABP into nuclei was studied. Rat liver cell nuclei and nuclear matrices (membrane depleted nuclei) were incubated in vitro with [1‐14C]18:0 and 20:4n‐6 either free or bound to L‐FABP, ATP and CoA. FA esterification in whole nuclei and endonuclear lipids was ATP‐CoA‐dependent, and with specificity regarding fatty acid type and lipid class. 18:0 and 20:4n‐6, free or L‐FABP bound, showed the same incorporation and esterification pattern in lipids of whole nuclei. Only 20:4n‐6 L‐FABP bound was less incorporated into TAG with respect to free 20:4n‐6. In the nuclear matrix, 18:0 free or L‐FABP bound was esterified with a higher specific activity (SA) into: PtdEtn > PtdIns, PtdSer > PtdCho. 20:4n‐6 free or L‐FABP bound was esterified into: PtdIns > PtdEtn > PtdCho. 20:4n‐6:L‐FABP was esterified in endonuclear total‐PL and PtdIns with a greater SA with respect to free 20:4n‐6 and with a minor one as FFA. To summarize, trafficking of FA to nuclei includes esterification of 18:0 and 20:4n‐6 either free or L‐FABP‐bound, into nuclear and endonuclear lipids by an ATP‐CoA‐dependent pathway. Endonuclear fatty acid esterification was more active than that in whole nuclei, and independent of the nuclear membrane. Esterification patterns of fatty acids L‐FABP‐bound or free into whole nuclear lipids were the same whereas in the nuclear matrix, L‐FABP could play an important role in the mobilization of 20:4n‐6 into specific sites of utilization such as the PtdIns pools.
Effects of Cigarette Smoke on Cell Viability, Linoleic Acid Metabolism and Cholesterol Synthesis, in THP−1 Cells
Authors: Ghezzi Silvia , Risé Patrizia , Ceruti Stefania , Galli Claudio 
Published: June 2007

AbstractCigarette smoke (CS) contains thousands of substances, mainly free radicals that have as a target the polyunsaturated fatty acids (PUFA). Long chain PUFA are produced through elongation and desaturation reactions from their precursors; the desaturation reactions are catalyzed by different enzymes: the conversion of 18:2n−6 (linoleic acid, LA) to 18:3n−6 by Δ6 desaturase, while that of 20:3n−6 to 20:4n−6 by Δ5 desaturase. The aim of this work is to evaluate the effect of serum exposed to cigarette smoke (SE‐FBS) on (1) cell viability and proliferation, (2) [1‐14C] LA conversion and desaturase activities in THP−1 cells, a monocytic cell line. In THP−1, CS inhibits cell proliferation dose‐dependently, by producing a modification in the cell cycle with a reduced number of cells in synthesis and mitosis phases at higher concentrations. CS also decreases [1‐14C] LA conversion to its derivatives in a concentration‐dependent manner, inhibiting the activities of Δ6 and mainly Δ5 desaturase. In addition, CS does not modify the incorporation of LA into various lipid classes but it reduces cholesterol synthesis from radiolabelled acetate, and increases free fatty acid, TG and CE levels. In conclusion, CS affects lipid metabolism, inhibiting LA conversion and desaturase activities. CS also shifts the “de novo” lipid synthesis from free cholesterol to TG and CE, where LA is preferentially esterified.
Effects of ethoxylate structure on surfactant properties of ethoxylated fatty methyl esters
Authors: Hama I. , Sakaki M. , Sasamoto H. 
Published: June 2007

AbstractIn the presence of a surface‐modified Al‐Mg composite oxide catalyst, ethoxylated fatty methyl esters with different hydrophobic group structures and different chain‐lengths of polyoxyethylene were synthesized from fatty methyl esters by direct ethoxylation. Each ethoxylated fatty methyl ester obtained showed a narrow ethylene oxide (EO) adduct distribution. Foaming, ability to lower surface tension, ability to lower interfacial tension, wettability, and dye solubilization were measured. Ethoxylated methyl laurate with about 60 to 70% EO content was found to be the most suitable as a base surfactant for household detergents
Methyl ester ethoxylates
Authors: Cox Michael F. , Weerasooriya Upali 
Published: June 2007

AbstractConventional ethoxylation of fatty methyl esters, or other fatty‐fatty esters or diesters, produces poor yields of the desired ethoxylated ester. A proprietary ethoxylation catalyst, currently in use to produce “peaked” or “narrow‐range” alcohol ethoxylates, has been found to successfully insert ethylene oxide into the ester linkage of fatty esters. The mechanism for this insertion likely involves an ethoxylation‐transesterification step in the ethoxylation process. Physical, performance, and environmental/human safety properties were evaluated. Results, in general, show that methyl ester ethoxylates behave similarly to alcohol ethoxylates with the exception of having a lower foam profile and being less irritating.
Chemo‐enzymatic synthesis of amino acid‐based surfactants
Authors: Valivety Rao , Jauregi Paula , Gill Iqbal , Vulfson Evgeny 
Published: June 2007

AbstractThe application of lipases to the synthesis of amino acid‐based surfactants was investigated. Low yields (2–9%) were obtained in the acylation of free amino acids, such as l‐serine and l‐lysine, as well as their ethyl esters and amides with fatty acids, owing in part to low miscibility of the reactants. When the N‐carbobenzyloxy (Cbz)‐l‐amino acids were used in an effort to improve miscibility of the amino acid derivatives with the acyl donor, a dramatic improvement was observed for N‐Cbz‐l‐serine (92% yield) but not for Nα‐Cbz‐ or Nζ‐Cbz‐l‐lysine (7 and 2% yield, respectively). As an alternative, and efficient synthesis of Nζ‐acyl‐l‐lysines was developed, based on the regiospecific chemical acylation of copper(II) lysinate. In pursuit of a general route to amino acid‐fatty acid surfactants, the utility of a polyol linker was investigated. Thus, the glycerol ester of Nα′Nζ‐di‐Cbz‐l‐lysine was prepared and evaluated as a substrate for acylation. As expected, this and other glycer‐1‐yl esters of N‐protected amino acids were excellent substrates for lipase‐catalyzed acylation. Their reaction with myristic acid in the presence of Novozyme resulted in the regioselective acylation of the primary hydroxyl group of the glycerol moiety to afford the corresponding 1‐O‐(N‐Cbz‐l‐aminoacyl)‐3‐O‐myris‐toylglycerols with conversions of 50–90%. These were readily deprotected to give a range of 1‐O‐(aminoacyl)‐3‐O‐myristoyl‐glycerols with overall yields of 27–71%.
Surfactant modification of lipases for lipid interesterification and hydrolysis reactions
Authors: Mogi Ken‐ichi , Nakajima Mitsutoshi , Mukataka Sukekuni 
Published: June 2007

AbstractCommercial grade lipases from Rhizopus japonicus, R. delemar, and Rhizomucor miehei were modified by surfactant (sorbitan monostearate), and their protein recovery and interesterification, and hydrolysis activities were investigated. By repeating the lipase modification processes three times, total protein recoveries of 17–35% could be obtained. The original lipases had no interesterification activities at all; however, all modified lipases in the first process had significant interesterification activities. In the hydrolysis reactions, all modified lipases obtained from the first process showed about three times higher specific activities than the original lipases. The modified lipases obtained from the second and third processes had lower specific interesterification and hydrolysis activities than the lipases from the first one. These results suggest that the surfactant modification process is effective not only for interesterification but also lipase purification.
Enzymatic enrichment of conjugated linoleic acid isomers and incorporation into triglycerides
Authors: McNeill Gerald P. , Rawlins Chris , Peilow Anne C. 
Published: June 2007

AbstractA method was developed for the enrichment of either the cis9,trans11 or the trans10,cis12 isomer of conjugated linoleic acid (CLA) from a synthetic CLA mixture consisting predominantly of these isomers in equal amounts. Lipases were screened for their ability to selectively esterify one isomer at a significantly greater rate than the other isomer. An immobilized lipase from Rhizomucor miehei was nonselective, but a lipase from Geotrichum candidum esterified the cis9,trans11 isomer more rapidly than the trans10,cis12 isomer. This selectivity was exploited at the kilogram scale to prepare an ester fraction with a content of 91% cis9,trans11 CLA and an unreacted free fatty acid fraction consisting of 82% trans10,cis12 CLA, based on total CLA content. The components of the reaction mixture were separated by molecular distillation. Each enriched fraction was then incorporated into palm oil triglycerides by interesterification with the non‐selective lipase from R. miehei. Two triglyceride fats resulted, which were enriched in either cis9,trans11 CLA (26.5% cis9,trans11 and 1.7% trans10,cis12) or trans10,cis12 CLA (3.5% cis9,trans11 and 22.9% trans10,cis12).
Challenges in capturing oxygenase activity in vitro
Authors: Vilker Vincent L. , Reipa Vytas , Mayhew Martin , Holden Marcia J. 
Published: June 2007

AbstractBiocatalysis using oxygenase or desaturase enzymes has the potential to add value to native fats and oils by adding oxygen, hydroxyl groups, or double bonds to create regio‐ and/or stereospecific products. These enzymes are a subset of the large class of oxidoreductase enzymes (from EC subgroups 1.13 and 1.14) involved with biological oxidation and reduction. In vitro biocatalytic processing using these enzymes is hampered by the high cost of the stoichiometric cofactors. This article reviews recent progress in developing in vitro redox enzyme biocatalysis for commercial‐scale syntheses. Coenzyme recycling and electrochemical redox cycling as methods for cofactor regeneration are described and commercial applications indicated. Direct charge transfer without use of mediators is described as the cleanest way of introducing the reducing power into the catalytic cycle. Our electrochemically driven cytochrome P450cam bioreactor is discussed as an example of direct charge transfer to a redox protein. Site‐directed mutagenesis in the active site of the P450cam monooxygenase greatly improved performance for the conversion of the nonnative substrate, styrene to styrene oxide. This epoxidation reaction was also shown to give a single product (styrene oxide) in the bioelectrochemical reactor when the diatomic oxygen co‐substrate was managed properly.
High yields of ascorbyl palmitate by thermostable lipase‐mediated esterification
Authors: Bradoo S. , Saxena R. K. , Gupta R. 
Published: June 2007

AbstractHigh yields of ascorbyl palmitate (6‐O‐palmitoyl‐l‐ascorbic acid) were obtained by lipase‐mediated esterification using Bacillus stearothermophilus SB 1 lipase. The final yield was greatly influenced by the initial water content of the system, quantity of enzyme, and molar ratio of palmitic acid to l‐ascorbic acid. Reaction rates increased directly with temperature from 40 to 100°C. Maximum conversion (97%) was achieved after 30 min at 100°C (solvent‐free), 1 h at 80°C (solvent‐free), and 2 h at 60°C (solvent/hexane). The synthesis was scaled up to 1‐l volume with 95% conversion using 50 mmoles of ascorbic acid and 250 mmoles of palmitic acid in hexane. Similar yields of ester were obtained in five repetitive cycles using 5 g enzyme immobilized on Accurel. The present B. stearothermophilus SB 1 lipase was a more efficient catalyst for the synthesis of ascorbyl palmitate than other commercial lipases.