palmitate hydrolase rph: Topics by WorldWideScience.org

Soluble epoxide hydrolase inhibition reveals novel biological functions of epoxyeicosatrienoic acids (EETs)

The production of Alternaria alternata f. sp. lycopersici host-specific toxins (AAL toxins) and epoxide hydrolase (EH) activity were studied during the growth of this...Full Text Available

1999-06-01

Soluble Epoxide Hydrolase as a Therapeutic Target for Cardiovascular Diseases

Early on, intriguing biological activities were found associated with the EETs using in vitro systems. Although the EETs other than the 5,6-isomer, are quite stable chemically,...Full Text Available

2007-01-01

Schindler disease: the molecular lesion in the alpha-N-acetylgalactosaminidase gene that causes an infantile neuroaxonal dystrophy.

PrefaceCardiovascular effects of epoxyeicosatrienoic acids (EETs) include vasodilation, vascular smooth muscle cell anti-migratory actions, and anti-inflammatory actions. These...Full Text Available

2009-10-01

Cloning and sequencing of a dehalogenase gene encoding an enzyme with hydrolase activity involved in the degradation of gamma-hexachlorocyclohexane in Pseudomonas paucimobilis.

Schindler disease is a recently recognized infantile neuroaxonal dystrophy resulting from the deficient activity of the lysosomal hydrolase, alpha-N-acetylgalctosaminidase (alpha-GalNAc). The recent...Full Text Available

1990-11-01

Characterization of Mouse UDP-glucose Pyrosphosphatase, a Nudix Hydrolase encoded by the Nudt14 Gene

In Pseudomonas paucimobilis UT26, gamma-hexachlorocyclohexane (gamma-HCH) is converted by two steps of dehydrochlorination to a chemically unstable intermediate, 1,3,4,6-tetrachloro-1,4-cyclohexadiene...Full Text Available

1993-10-01

Supplementation of pyruvate prevents palmitate-induced impairment of glucose uptake in C2 myotubes.

Recombinant mouse UDP-glucose pyrophosphatase (UGPPase), encoded by the Nudt14 gene, was produced in Escherichia coli and purified close to homogeneity. The...Full Text Available

2009-12-25

Science.gov (United States)

Elevated fatty acid levels have been thought to contribute to insulin resistance. Repression of the glucose transporter 4 (GLUT4) gene as well as impaired GLUT4 translocation may be a mediator for fatty acid-induced insulin resistance. This study was initiated to determine whether palmitate treatment repressed GLUT4 expression, whether glucose/fatty acid metabolism influenced palmitate-induced GLUT4 gene repression (PIGR), and whether attempts to prevent PIGR restored palmitate-induced impairment of glucose uptake (PIIGU) in C2 myotubes. Not only stimulators of fatty acid oxidation, such as bezafibrate, AICAR, and TOFA, but also TCA cycle substrates, such as pyruvate, leucine/glutamine, and ?-ketoisocaproate/monomethyl succinate, significantly prevented PIGR. In particular, supplementing with pyruvate through methyl pyruvate resulted in nearly complete prevention of PIIGU, whereas palmitate treatment ...

2011-07-23

Automated production of ["1"1C]acetate and ["1"1C]palmitate using a modified GE Tracerlab FX_C_-_P_r_o

Inhibition of HIV-1 Infection in Ex Vivo Cervical Tissue Model of Human Vagina by Palmitic Acid; Implications for a Microbicide Development

As researchers explore new applications for positron emission tomography radiopharmaceuticals, the demand for effective and readily available radiopharmaceuticals continues to increase. The syntheses of two such radiopharmaceuticals, ["1"1C]acetate and ["1"1C]palmitate, can be automated on the GE Tracerlab FX_C_-_P_r_o by utilizing Grignard reactions. Radiochemical purities of the ["1"1C]acetate and the ["1"1C]palmitate products were high (>98% and >99.9%, respectively) with average non-corrected yields of 18% (n=3) and 10% (n=5), respectively. These data comprise the validation trials for site qualification of clinical production of both radiopharmaceuticals. -- Graphical abstract: Automated syntheses of ["1"1C]acetate and ["1"1C]palmitate using a modified GE Tracerlab FX_C_-_P_r_o are reported. Radiochemical purities of the ["1"1C]acetate and the ["1"1C]palmitate products were high (>98% and ...

2011-04-01

Crystallization and preliminary X-ray diffraction studies of two thermostable ?-galactosidases from glycoside hydrolase family 36

BackgroundApproximately 80% of all new HIV-1 infections are acquired through sexual contact. Currently, there is no clinically approved microbicide, indicating a clear and...Full Text Available

Quantitation of fatty acids by GLC and separation of omega-6 nutraceutical fatty acid from carthamus tinctorius L. seed oil cultivated in Pakistan

α-Galactosidases from thermophilic organisms have gained interest owing to their applications in the sugar industry. The α-galactosidases AgaA, AgaB and AgaA A355E mutant from Geobacillus...Full Text Available

Time-of-flight secondary ion mass spectrometry of fatty acids in rat retina

The GLC analysis of carthamus tinctorius (safflower) yielded average hexane extracted oil content of 28% (25-30%); the oil contained high level of linoleic acid (74%). Monounsaturated fatty acid, oleic acid amounted 12.94%, while the saturated fatty acids like palmitic acid and stearic acid were 9.43 and 1.81%, respectively. Iodine value of linoleic acid was found to be 160:1 while its purity was 93.1%. (author)

2008-01-01

Lauric and palmitic acids eutectic mixture as latent heat storage material for low temperature heating applications

The retina consists of many kinds of central nervous cells, and some cells contain fatty acids such as palmitic acid, stearic acid and oleic acid. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has a possibility to detect kinds and quantity of materials in relation to the cell or tissue. We applied TOF-SIMS to detect the palmitic acid, stearic acid and oleic acid in the visual cell of the rat retina. We used 4- and 18-month-old normal Wistar Kyoto rats. After pentobarbital anesthesia, the eyes were enucleated, and immediately put into liquid nitrogen without any fixation and then cut into semithin sections (10 {mu}m) with a cryo-ultramicrotome, and laid it on a silicon wafer plate and air-dried. Ion images were detected with TOF-SIMS. Positive ion images were examined with a Ga{sup +} source at an acceleration voltage of 15 keV. The secondary ion acceleration voltage was 4.5 keV. In the 4-month-old rat, palmitic ...

2003-01-15

Optimization of amide-based inhibitors of soluble epoxide hydrolase with improved water solubility.

Palmitic acid (PA, 59.8 {sup o}C) and lauric acid (LA, 42.6 {sup o}C) are phase change materials (PCM) having quite high melting temperatures which can limit their use in low temperature solar applications such as solar space heating and greenhouse heating. However, their melting temperatures can be tailored to appropriate value by preparing a eutectic mixture of the lauric and the palmitic acids. In the present study, the thermal analysis based on differential scanning calorimetry (DSC) technique shows that the mixture of 69.0 wt% LA and 31 wt% PA forms a eutectic mixture having melting temperature of 35.2 {sup o}C and the latent heat of fusion of 166.3 J g{sup -1}. This study also considers the experimental determination of the thermal characteristics of the eutectic mixture during the heat charging and discharging processes. Radial and axial temperature distribution, heat transfer coefficient between the heat transfer fluid (HTF) pipe and ...

2005-04-01

Science.gov (United States)

Soluble epoxide hydrolase (sEH) plays an important role in the metabolism of endogenous chemical mediators involved in the regulation of blood pressure and inflammation. 1,3-Disubstituted ureas with a polar group located on the fifth atom from the carbonyl group of urea function are active inhibitors of sEH both in vitro and in vivo. However, their limited solubility in water and relatively high melting point lead to difficulties in formulating the compounds and poor in vivo efficacy. To improve these physical properties, the effect of structural modification of the urea pharmacophore on the inhibition potencies, water solubilities, octanol/water partition coefficients (log P), and melting points of a series of compounds was evaluated. For murine sEH, no loss of inhibition potency was observed when the urea pharmacophore was modified to an amide function, while for human sEH 2.5-fold decreased inhibition was obtained in the amide compounds. In addition, a NH group ...

2005-05-19

Numerical heat transfer studies of the fatty acids for different heat exchanger materials on the performance of a latent heat storage system

Mechanism of solubilization in detergent solutions

Theoretical investigations of fatty acids as a phase change material (PCM) for energy storage system have been conducted in this study. The selected fatty acids were capric acid, lauric acid, myristic acid, palmitic acid and stearic acid. For the two-dimensional simulation model based on the enthalpy approach, calculations have been made for the melt fraction with conduction only. Glass, stainless steel, tin, aluminium mixed, aluminium and copper were used as heat exchanger materials in the numerical calculations. Theoretical results show that capric acid was found good compatibility with latent heat storage system. The large value of thermal conductivity of heat exchanger materials did not make significant contribution on the melt fraction. (author)

2005-11-01

Chemical transformations of peptide containing fine particles: oxidative processing, accretion reactions and implications to the atmospheric fate of cell-derived materials in organic aerosol

The kinetics of the solubilization of lauric acid, palmitic acid, stearic acid, and monopalmitin have been studied in detergent solutions as a function of concentration, temperature, and fluid flow. The detergents used were sodium dodecyl sulfate (an anionic surfactant), decyltrimethylammonium bromide (a cationic surfactant), sodium taurocholate (a trihydroxy bile salt), sodium taurodeoxycholate (a dihydroxy bile salt), and triton X-100 (a nonionic surfactant). At low temperature, solubilization can be described by a five-step mechanism is which micelle desorption and diffusion are rate controlling. At temperatures above the fatty acid penetration temperature, solubilization is governed by formation of a liquid crystalline phase at the fatty acid-detergent solution interface.

1981-11-01

British Library Electronic Table of Contents (United Kingdom)

The atmospheric processing by ozone of peptide-containing mixed particles was investigated as proxies for biogenic and sea spray primary organic aerosol. Reactions were performed in a flow reactor and particle composition was monitored by photoelectron resonance capture ionization aerosol mass spectrometry. Mixed particles containing dipeptides in a saturated organic matrix of stearic and palmitic acids showed no reaction under ozonolysis at exposure levels of 2.5???10?4?atm s O3. However reactions of mixed particles of a dipeptide (Leu-Leu) in an unsaturated matrix (oleic acid) under the same conditions resulted in a rapid loss of the peptide ion signal, as well as the carrier matrix, and appearance of a number of ion signals corresponding to secondary products. High molecular weight imid...

2009-01-01

Nuclear Targeting of Methyl-Recycling Enzymes in Arabidopsis thaliana Is Mediated by Specific Protein Interactions.

Science.gov (United States)

Numerous transmethylation reactions are required for normal plant growth and development. S-adenosylhomocysteine hydrolase (SAHH) and adenosine kinase (ADK) act coordinately to recycle the by-product of these reactions, S-adenosylhomocysteine (SAH) that would otherwise competitively inhibit methyltransferase (MT) activities. Here, we report on investigations to understand how the SAH produced in the nucleus is metabolized by SAHH and ADK. Localization analyses using green fluorescent fusion proteins demonstrated that both enzymes are capable of localizing to the cytoplasm and the nucleus, although no obvious nuclear localization signal was found in their sequences. Deletion analysis revealed that a 41-amino-acid segment of SAHH (Gly(150)-Lys(190)) is required for nuclear targeting of this enzyme. This segment is surface exposed, shows unique sequence conservation patterns in plant SAHHs, and possesses additional features of protein-protein interaction motifs. ADK ...

2011-10-01

Expression profiles of PtrLOS2 encoding an enolase required for cold-responsive gene transcription from trifoliate orange

British Library Electronic Table of Contents (United Kingdom)

Low expression of osmotically responsive genes 2 (LOS2) encodes an enolase (2-phospho-D-glycerate hydrolase, EC 4.2.1.11) that converts 2-phospho-D-glycerate (PGA) to phosphoenolpyruvate (PEP) in the glycolytic pathway in Arabidopsis. Meanwhile, it is a transcriptional activator of cold-responsive gene, negatively controlling the expression of STZ/ZAT10, a zinc finger transcriptional repressor of cold-responsive gene from Arabidopsis. A novel LOS2 gene, designated PtrLOS2 (GenBank accession number GQ144341), was isolated from trifoliate orange [Poncirus trifoliata (L.) Raf.]. The PtrLOS2 cDNA is 1 662 bp in length with a 1 338 bp open reading frame (ORF), encoding a deduced 445 amino acid residue protein with a predicted molecular mass of 47.79 kDa and an isoelectric point of 5.54. The ded...

2011-01-01

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Thermal properties and thermal reliability of eutectic mixtures of some fatty acids as latent heat storage materials

Some fatty acids used for latent heat storage: thermal stability and corrosion of metals with respect to thermal cycling

The present study deals with two subjects. The first one is to determine the thermal properties of lauric acid (LA)-stearic acid (SA), myristic acid (MA)-palmitic acid (PA) and palmitic acid (PA)-stearic acid (SA) eutectic mixtures as latent heat storage material. The properties were measured by the differential scanning calorimetry (DSC) analysis technique. The second one is to study the thermal reliability of these materials in view of the change in their melting temperatures and latent heats of fusion with respect to repeated thermal cycles. For this aim, the eutectic mixtures were subjected to 360 repeated melt/freeze cycles, and their thermal properties were measured after 0, 90,1 80 and 360 thermal cycles by the technique of DSC analysis. The DSC thermal analysis results show that the binary systems of LA-SA in the ratio of 75.5:24.5 wt.%, MA-PA in the ratio of 58:42 wt.% and PA-SA in the ratio of 64.2:35.8 wt.% form eutectic mixtures ...

2004-02-01

Metabolic relationships between monogalactosyldiacylglycerol and digalactosyldiacylglycerol molecular species in Dunaliella salina

The present study includes thermal stability of some fatty acids as phase change materials (PCMs). The selected fatty acids were stearic, palmitic, myristic and lauric acid with melting temperatures between 40-63{sup o}C and industrial-grade with 90-95% purity. Latent heat storage capacity and phase transition temperature of the PCMs were determined by Differential Scanning Calorimetry (DSC) technique as a function of after repeated thermal cycles such as 40, 410, 700 and 910. The present work also comprises the investigation of corrosion resistance of some construction materials to the fatty acids over a long period. The containment materials tested were stainless steel (SS 304 L), carbon steel (steel C20), aluminium (Al) and copper (Cu). Gravimetric analysis as mass loss (mg/cm{sup 2}), corrosion rate (mg/day) and a microscopic or metallographic investigation were performed for corrosion tests after 910 thermal cycles. DSC measurements showed that all fatty acids ...

2003-05-01

Thermal reliability test of some fatty acids as PCMs used for solar thermal latent heat storage applications

Dunaliella salina cells were pulse-labeled for 2 min with (/sup 14/C)palmitic acid, (/sup 14/C)oleic acid, or (/sup 14/C)lauric acid in order to trace the pathway of galactolipid biosynthesis and desaturation. Through the use of high performance liquid chromatography it was possible to follow the movement of radioactivity through many individual molecular species of monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) for periods of 24 h and, in some cases, as much as 120 h. Analysis of the fatty acid fluxes permitted us to refine current views regarding biosynthesis of the predominantly prokaryotic galactolipids. The initial D. salina MGDG molecular species, containing paired oleate and palmitate (18:1/16:0), can follow two metabolic routes. If the palmitoyl chain is desaturated to 16:1, the resulting 18:1/16:1 MGDG is subject to rapid further desaturation to varying degrees, and a part of these products is subsequently ...

1987-06-05

Thermal reliability test of some fatty acids as PCMs used for solar thermal latent heat storage applications

The purpose of this study is to determine the thermal reliability of stearic acid, palmitic acid, myristic acid and lauric acid as latent heat energy storage materials with respect to various numbers of thermal cycles. The fatty acids, as phase change materials (PCMs), of industrial grade (purity between 90% and 97%) were subjected to accelerated thermal cycle tests. The differential scanning calorimetry (DSC) analysis technique was applied to the PCMs after 0, 120, 560, 850 and 1200 melt/freeze cycles in order to measure the melting temperatures and the latent heats of fusion of the PCMs. The DSC results indicated that the change in melting temperature for the PCMs was in the range of 0.07-7.87 {sup o}C, and the change in latent heat of fusion was -1.0% to -27.7%, except for stearic acid between 560 and 1200 melt/freeze cycles. However, the decrease in the latent heats of fusion for all the PCMs was not regular with increasing thermal cycles. The experimental ...

2003-08-01

The response of quartz crystals coated with thin fatty acid film to organic gases

The purpose of this study is to determine the thermal reliability of stearic acid, palmitic acid, myristic acid and lauric acid as latent heat energy storage materials with respect to various numbers of thermal cycles. The fatty acids, as phase change materials (PCMs), of industrial grade (purity between 90% and 97%) were subjected to accelerated thermal cycle tests. The differential scanning calorimetry (DSC) analysis technique was applied to the PCMs after 0, 120, 560, 850 and 1200 melt/freeze cycles in order to measure the melting temperatures and the latent heats of fusion of the PCMs. The DSC results indicated that the change in melting temperature for the PCMs was in the range of 0.07-7.87 deg. C, and the change in latent heat of fusion was -1.0% to -27.7%, except for stearic acid between 560 and 1200 melt/freeze cycles. However, the decrease in the latent heats of fusion for all the PCMs was not regular with increasing thermal cycles. The experimental ...

2003-08-01

Preliminary studies on the detection of irradiated prawns using 2-alkylcyclobutanones

We tried to apply a quartz crystal as a sensor by using the resonant frequency and the resistance properties of quartz crystals. Four kinds of fatty acids that have the same head groups were coated on the surfaces of the quartz crystals, and the shift of the resonant frequency and the resistance were observed based on the lengths of the tail groups. Myristic acid (C{sub 14}), palmitic acid (C{sub 16}), stearic acid (C{sub 18}), and arachidic acid (C{sub 20}) were deposited on the surfaces of quartz crystals by using the Langmuir-Blodgett (LB) method. As a result, the resonant frequency change was more sensitive to high molecular-weight fatty acids than to low molecular-weight ones. We also observed the effect of temperature on stearic acid LB films, and the response properties of quartz crystals coated with stearic-acid LB films to organic gases were investigated. As a result, the sensitivity of quartz crystals to organic gases was higher for higher ...

1999-07-01

Morphology and thermal properties of electrospun fatty acids/polyethylene terephthalate composite fibers as novel form-stable phase change materials

The use of ionising radiation for the preservation of food has been under investigation for many years but has yet to receive worldwide acceptance. Although irradiation can be carefully controlled, it is generally accepted that the development of a test or tests for the detection of irradiated food would enhance consumer confidence and might help to enforce labelling regulations. The 2-alkylcyclobutanones are reported to be the only cyclic compounds formed as the products of the radiolysis of saturated and unsaturated triglycerides. The synthesis of 2-dodecylcyclobutanone (DCB) and 2-tetradecylcyclobutanone (TCB), which are formed from palmitic and stearic acid respectively following irradiation, has been carried out and using irradiated chicken meat as the model for a high-lipid containing food, both cyclobutanones have been extracted with hexane and then identified using gas chromatography/mass spectrometry (GC/MS). DCB and TCB have been detected in chicken meat ...

1996-12-31

Molar extinction coefficients of some fatty acids

The ultrafine fibers based on the composites of polyethylene terephthalate (PET) and a series of fatty acids, lauric acid (LA), myristic acid (MA), palmitic acid (PA), and stearic acid (SA), were prepared successfully via electrospinning as form-stable phase change materials (PCMs). The morphology and thermal properties of the composite fibers were studied by field emission scanning electron microscopy (FE-SEM) and differential scanning calorimetry (DSC), respectively. It was found that the average fiber diameter increased generally with the content of fatty acid (LA) in the LA/PET composite fibers. The fibers with the low mass ratio maintained cylindrical shape with smooth surface while the quality became worse when the mass ratio is too high (more than 100/100). Moreover, the latent heat of the composite fibers increased with the increase of LA content and the phase transition temperature of the fibers have no obvious variations compared with LA. In contrast, ...

2008-11-15

Effect of paraquat on microsomal lipid peroxidation in vitro and in vivo. [Rats, rabbits, man, mice

The attenuation of gamma rays in some fatty acids, viz. formic acid (CH_2O_2), acetic acid (C_2H_4O_2), propionic acid (C_3H_6O_2), butyric acid (C_4H_8O_2), n-hexanoic acid (C_6H_1_2O_2), n-caprylic acid (C_8H_1_6O_2), lauric acid (C_1_2H_2_4O_2), myristic acid (C_1_4H_2_8O_2), palmitic acid (C_1_6H_3_2O_2), oleic acid (C_1_8H_3_4O_2) and stearic acid (C_1_8H_3_6O_2), has been measured at the photon energies 81, 356, 511, 662, 1173 and 1332 keV. Experimental values for the molar extinction coefficient, the effective atomic number and the electron density have been derived and compared with theoretical calculations. There is good agreement between experiment and theory.

2002-10-01

Bip overexpression, but not CHOP inhibition, attenuates fatty-acid-induced endoplasmic reticulum stress and apoptosis in HepG2 liver cells

Rat lung and liver microsomes did not undergo lipid peroxidation in the absence of iron when incubated with NADPH and concentrations of paraquat ranging from 10/sup -7/ to 10/sup -2/ M. Paraquat also did not stimulate rat liver and lung microsomal peroxidation induced by added iron and NADPH, and was inhibitory at concentrations above 10 ..mu..M. Similarly, no stimulation of peroxidation was produced by paraquat in rabbit or human lung microsomes; however, under similar conditions, paraquat enhanced NADPH/iron-dependent peroxidation in mouse lung and liver microsomes obtained from rats sacrificed at 12, 18, and 24 hr following a lethal dose of paraquat (50 mg/kg, ip), there was no loss of vitamin E or increase in susceptibility to in vitro peroxidation which would be expected if lipid peroxidation had occurred in vivo although extensive lung damage developed during this time period. These results indicate that paraquat does not cause pulmonary toxicity by initiating peroxidation of ...

1980-01-01

British Library Electronic Table of Contents (United Kingdom)

Aims: In this study we investigated whether attenuation of endoplasmic reticulum stress (ER stress) could protect HepG2 cells from free fatty acid (FFA)-induced apoptosis. Main methods: Human liver cell line HepG2 cells were exposed to Sodium Palmitate (Pa) or Sodium Oleate (Ol). Apoptosis and ER stress of HepG2 cells were analyzed with flow cytometry, real-time RT-PCR and Western Blotting. An expression plasmid encoding for the ER chaperone immunoglobulin heavy chain-binding protein (Bip) was transfected into HepG2 cells to attenuate ER stress. Small interfering RNA siCHOP was used to knockdown the expression of C/EBP Homologous Protein (CHOP) in HepG2. Key findings: Pa led to cytotoxicity and apoptosis in HepG2 cells in a dose-dependent pattern and also induced ER stress indicated by inc...

2010-01-01

Antioxidant properties of natural substances in irradiated fresh poultry

Crystal Structure of Human Senescence Marker Protein 30: Insights Linking Structural, Enzymatic, and Physiological Functions

This study was undertaken to determine if a combined treatment (marinating in natural plant extracts or vacuum) with irradiation could have a synergistic effect, in order to prevent the lipid oxidation resulting in the development of undesirable flavours. The fresh chicken legs were irradiated at 0,3 and 5 kGy. The fatty acids composition of lipids was identified using gas liquid chromatography. The effect of irradiation treatment combined with a pre-treatment on the fatty acids composition was followed. The day after irradiation, ten panallists were asked to evaluate, using the instruction scaling, the overall appearance, the odor, the flavor and the overall acceptability of the samples. The major fatty acids identified in lipids were oleic acid, palmitic acid, palmitoleic acid and stearic acid. Pre-treatments have a significant effect on linoleic acid (C18:2) and higher fatty acids. The unsaturated fatty acids derived from phospholipids appeared to be more ...

1998-06-01

Thermal energy storage performance of fatty acids as a phase change material

Human senescence marker protein 30 (SMP30), which functions enzymatically as a lactonase, hydrolyzes various carbohydrate lactones. The penultimate step in vitamin-C biosynthesis is catalyzed by this enzyme in nonprimate mammals. It has also been implicated as an organophosphate hydrolase, with the ability to hydrolyze diisopropyl phosphofluoridate and other nerve agents. SMP30 was originally identified as an aging marker protein, whose expression decreased androgen independently in aging cells. SMP30 is also referred to as regucalcin and has been suggested to have functions in calcium homeostasis. The crystal structure of the human enzyme has been solved from X-ray diffraction data collected to a resolution of 1.4 {angstrom}. The protein has a 6-bladed {beta}-propeller fold, and it contains a single metal ion. Crystal structures have been solved with the metal site bound with either a Ca{sup 2+} or a Zn{sup 2+} atom. The catalytic role of the metal ion has been ...

2010-05-25

Physicochemical characterization and thermal behavior of guanabana (Annona muricata) seed almond oil; Caracterizacion fisicoquimica y comportamiento termico del aceite de almendra de guanabana (Annona muricata, L)

Thermal energy storage performance of fatty acids and a eutectic mixture as phase change materials (PCMs) has been investigated experimentally. The selected PCMs for this study were palmitic acid, myristic acid, stearic acid, and a mixture of stearic and myristic acids in eutectic combination ratio of 65.7 wt% myristic acid and 34.3 wt% stearic acid. The PCMs have a melting temperature range of 50.0{sup o}C to 61.20{sup o}C and a latent heat range of 162.0 J/g to 204.5 J/g. The inlet temperature and the mass flow rate of heat transfer fluid (HTF) were selected as experimental parameters to test the thermal energy storage performance of the PCMs. The transition times, temperature range, propagation of the solid-liquid interface, as well as heat flow rate characteristics of the employed cylindrical tube storage system were studied at varied experimental parameters. The experimental results show that the melting front moves to inward in the radial directions as well ...

2006-01-21

Influence of lipolysis on the mobilization of 2,4,5,2'4',5'-hexachlorobiphenyl from adipocytes in vitro

In this work some physicochemical properties and the thermal behavior and stability of sour sop or guanabana (Annona muricata) seed almond oil were studied by means of chemical, DSC and TG analysis. The results showed that the almond has 2.5% ash, 17.9% crude fiber, 15.7% protein, 26.0% de carbohydrates and 37.7% oil (dry base). The composition of almond oil showed 68.5% unsaturated fatty acids, mainly oleic and linoleic, and some palmitoleic acids, and 31.5% saturated, principally palmitic and stearic fatty acids; refraction index was 1.468 and saponification and iodine value were 168.2 and 87.0, respectively. DSC thermal analysis showed that oil crystallization initiates at -4.5 degree centigrade and ends at -79.0 degree centigrade with a crystallization enthalpy of 48.2 J/g; the oil melts in a temperature range from -42.4 to -16.9 degree centigrade, with a maximum peak at -15 degree centigrade and a fusion enthalpy of 80.5 J/g. The oil remained liquid at ...

2010-07-01

Genotoxicity of 2-alkylcyclobutanones, markers for an irradiation treatment in fat-containing food--Part I: cyto- and genotoxic potential of 2-tetradecylcyclobutanone

Epididymal adipocytes, isolated from rats pretreated with (/sup 14/C)-2,4,5,2',4',5'-hexachlorobiphenyl (6-CB), were utilized to examine the relationship between the mobilization of lipid and 6-CB and to determine whether 6-CB was differentially associated with subcellular organelles over time as has been demonstrated for newly synthesized lipid. Lipolysis, depleted approximately 1% of total cellular triacylglycerols (TG) regardless of time from treatment with 6-CB. The percentage of cellular 6-CB released from adipocytes to incubation buffer infranatants was not correlated with the magnitude of lipolysis produced over the 50-min incubation period; nor was the percentage of 6-CB released to the buffers correlated with the length of the incubation period, regardless of the presence of ISO. Although adipocytes responded similarly to lipolytic stimuli independent of time (days) since 6-CB treatment, significant decreases were found in the percentage of 6-CB ...

1987-01-01

Effect of dietary fatty acid intake on prospective weight change in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition

Previous experiments had indicated a slight genotoxic potential both in rat and in human colon cells of a sample of 2-dodecylcyclobutanone, a compound formed by irradiation of food containing palmitic acid in its triglycerides. Up to date, there is no evidence that 2-alkylcyclobutanones occur in non-irradiated foodstuffs, consequently it is prudent to test several members of the class of 2-alkylcyclobutanones which are produced by treatment of fat-containing food with ionising radiation. In this work, 2-tetradecylcyclobutanone (derived from stearic acid) has been tested for its cytotoxic and genotoxic potential. Human colon tumor cell lines, i.e. HT 29 and HT 29 clone 19A, were employed as models for in vitro experiments for cytotoxicity and genotoxicity tests. Cytotoxicity was measured by tetrazolium salt reduction assays (MTT and WST-1) and genotoxicity by determining DNA damage using the Comet Assay. Neither cytotoxic nor genotoxic effects were induced by 2-TCB ...

2002-03-01

DEFF Research Database (Denmark)

OBJECTIVE: To evaluate the association between fatty acid (alpha-linolenic acid (ALA), EPA, DHA, palmitic, stearic, oleic, linoleic and arachidonic acids) intake and prospective weight change in the Heidelberg cohort of the European Prospective Investigation into Cancer and Nutrition. DESIGN: Prospective cohort study with mean follow-up time of 6.5 years. In a total of 9182 men and 10867 women aged 35 to 64 years, from body weight measurement at recruitment and calibrated body weight during follow-up, weight change was expressed as mean annual weight change relative to baseline weight (%/year) and categorised into four groups (weight loss, or =2.5 to or =7.5%/5 years). Energy-adjusted dietary fatty acid intake data were estimated from the FFQ completed at baseline. Multivariate linear regression models as well as multinomial logistic regression analyses (carbohydrate replacement models) were conducted. RESULTS: Stearic acid intake was linearly associated with ...

2010-01-01

Fatty acid/poly(methyl methacrylate) (PMMA) blends as form-stable phase change materials for latent heat thermal energy storage