Fractionation Research Papers - Academia.edu (original) (raw)

Structural information on soil organic matter (SOM) at the molecular level can be obtained on diverse structural units that are amenable to degradation techniques. Chemolytic techniques in combination with colorimetric analyses or GC MS... more

Structural information on soil organic matter (SOM) at the molecular level can be obtained on diverse structural units that are amenable to degradation techniques. Chemolytic techniques in combination with colorimetric analyses or GC MS are used to determine amino acids (proteins), sugars (polysaccharides), lipids, or aromatic oxidation products from lignin or charred organic matter. Microbial markers (amino sugars, muramic acid) are analyzed after hydrolysis and gas chromatographic separation. Macromolecular structures can also be subjected to thermochemolytic degradation or pyrolysis and subsequent analysis of the fragments by GC MS. Alternative techniques for the examination of organic matter in heterogeneous macromolecular mixtures are non-destructive spectroscopic methods, such as nuclear magnetic resonance (NMR) spectroscopy. Although this technique can give good results concerning the gross chemical composition, speci®c compounds are hardly identi®ed. The combination of spectroscopic techniques with thermolytic and chemolytic methods will add substantially to the understanding of the nature of refractory soil organic matter. Physical fractionation prior to analysis provides a means to dierentiate between distinct SOM pools that can be further characterized by the methods described above. Studies on SOM structural characteristics have focused mainly on the A horizons of soils under agriculture and litter biodegradation in forest soils and need to be extended to a wider variety of soil types and the subsoil. #

1] We have incorporated the cycling of water isotopes into the NCAR atmospheric general circulation model, CAM2. Isotope dynamics mostly follow those of previous isotope GCMs, with fractionation being produced by evaporation at the... more

1] We have incorporated the cycling of water isotopes into the NCAR atmospheric general circulation model, CAM2. Isotope dynamics mostly follow those of previous isotope GCMs, with fractionation being produced by evaporation at the surface and by cloud processes. A new feature that we have added is the direct estimation of the degree of isotopic equilibration between vapor and raindrops as a function of temperature and rain rate. The model yields a reasonable global pattern of water isotopes in precipitation, but detailed comparison with observations is limited by known inaccuracies in precipitation and temperatures yielded by CAM2. We use the results to evaluate the fundamental controls on water isotopic composition in precipitation. We emphasize that, over much of the surface of the Earth, the concept of Rayleigh distillation is inadequate to understand the large-scale geographic distribution of water isotopes in precipitation, because the effects of surface fluxes are more important than those of distillation, in particular at low and midlatitudes and over the oceans. In oceanic regions the balance between precipitation and evaporation (P À E), which reflects the large-scale atmospheric circulation, is the primary determinant of the isotopic composition of precipitation and vapor. Variations of P À E at low latitudes over the oceans produce about 7% variation of precipitation d 18 O that is independent of temperature variation. Where P > E, the convergence of atmospheric vapor derived from various sources leads to low values and a particularly wide range in d ppt . In the tropical and subtropical troposphere the vertical decrease of d 18 O in vapor is different from the values expected from Rayleigh distillation because of entrainment, convective mixing, detrainment, evaporation of detrained water, and subsidence of low-d 18 O highaltitude air. The low d 18 O of atmospheric vapor over the oceans at high (ca. 55°) latitudes produces, as a result of kinetic effects associated with evaporation, a zone of heavy (high-d 18 O) evaporation from the oceans. This effect may account for the low d 18 O of some high-latitude ocean surface waters and also helps attenuate the effects of global temperature changes on the isotopic composition of polar precipitation.

Major hen egg white proteins have been widely studied for their functional properties but these studies still are unable to explain, alone, all of the biological properties of hen egg white. Hence, it is still interesting to produce pure... more

Major hen egg white proteins have been widely studied for their functional properties but these studies still are unable to explain, alone, all of the biological properties of hen egg white. Hence, it is still interesting to produce pure and non-altered proteins to improve our knowledge on the biological properties of hen egg white. Presently, identification and characterization of both bioactive peptides and minor proteins from hen egg white is essential work for progressing in the understanding of hen egg white biological properties. With this objective in mind, a new process for a complete "mucin free" hen egg white fractionation based on ion exchange chromatography is proposed. "Mucin free" egg white is fractionated into six different fractions. Four of them are high-recovery yield purified fractions of lysozyme, ovotransferrin, ovalbumin and flavoprotein. The two other fractions are enriched in recently detected minor proteins in hen egg white.

Although well-established as a technique for protein purification, the application of continuous elution tube gel electrophoresis to proteome fractionation remains problematic. Difficulties associated with sample collection, particularly... more

Although well-established as a technique for protein purification, the application of continuous elution tube gel electrophoresis to proteome fractionation remains problematic. Difficulties associated with sample collection, particularly at the high mass range or at low sample loadings, continue to plague the technique. Furthermore, an upper mass limit is imposed as slow-moving higher molecular weight proteins are progressively diluted during the collection phase. In short, with current technology, effective separation over a broad mass range has not been achieved. In this work, we present improved techniques for continuous elution tube gel electrophoresis to accommodate broad mass range separation of proteins. Our device enables rapid partitioning of a proteome into discrete mass range fractions in the solution phase. High recovery is achieved at submicrogram to milligram sample loadings. We demonstrate comprehensive, reproducible separations of protein mixtures, as well as separation of a proteome in as fast as 1 h, over mass ranges from below 10 to 250 kDa. Finally, we identified proteins from a prefractionated standard protein mixture using liquid chromatography tandem mass spectrometric (LC-MS/ MS) analysis.

Pine bark is a forest by-product that can be profitable as a source of polyphenols by its content in procyanidins. In this work, barks of two varieties of pine (Pinus pinaster and P. radiata) were extracted with ethanol, and partially... more

Pine bark is a forest by-product that can be profitable as a source of polyphenols by its content in procyanidins. In this work, barks of two varieties of pine (Pinus pinaster and P. radiata) were extracted with ethanol, and partially purified to obtain a fraction named FOW, that contained mainly flavan-3-ol monomers and procyanidins oligomers. The mean degree of polymerization was 2.1 for pinaster (pOW) and 2.7 for radiata (rOW). FOWs were fractionated on C 18 Sep-Pak cartridges into three fractions for each variety by different organic solvents. The phenolic compositions of the fractions were analyzed using HPLC with UV diode array detection and electrospray-ionization mass spectrometry. The compounds identified were: catechin, dihydroquercetin, phenolic acids and their glucosides, procyanidins dimers, trimers and tetramers. FOWs and their fractions were characterized in antioxidant power by DPPH and b-carotene methods. In the former assay, pOW showed major effectiveness, with an antiradical specific activity of 46 units AR/mg procyanidins, whereas for the b-carotene bleaching test rOW (78 ± 0.71%) gave the best inhibition result. Despite this fact the derived fractions, presenting similar values, have advantages because the profile of their constituents is uniform for each one, and, hence, it is easier to investigate their action for potential applications in both medical or food fields

Increasing atmospheric pCO 2 reduces the saturation state of seawater with respect to the aragonite, high-Mg calcite (Mg/Ca N 0.04), and low-Mg calcite (Mg/Ca b 0.04) minerals from which marine calcifiers build their shells and skeletons.... more

Increasing atmospheric pCO 2 reduces the saturation state of seawater with respect to the aragonite, high-Mg calcite (Mg/Ca N 0.04), and low-Mg calcite (Mg/Ca b 0.04) minerals from which marine calcifiers build their shells and skeletons. Notably, these polymorphs of CaCO 3 have different solubilities in seawater: aragonite is more soluble than pure calcite, and the solubility of calcite increases with its Mg-content. Although much recent progress has been made investigating the effects of CO 2-induced ocean acidification on rates of biological calcification, considerable uncertainties remain regarding impacts on shell/skeletal polymorph mineralogy. To investigate this subject, eighteen species of marine calcifiers were reared for 60-days in seawater bubbled with air-CO 2 mixtures of 409 ± 6, 606 ± 7, 903 ± 12, and 2856 ± 54 ppm pCO 2 , yielding aragonite saturation states (Ω A) of 2.5 ± 0.4, 2.0 ± 0.4, 1.5 ± 0.3, and 0.7 ± 0.2. Calcite/aragonite ratios within bimineralic calcifiers increased with increasing pCO 2 , but were invariant within monomineralic calcifiers. Calcite Mg/Ca ratios (Mg/Ca C) also varied with atmospheric pCO 2 for two of the five high-Mg-calciteproducing organisms, but not for the low-Mg-calcite-producing organisms. These results suggest that shell/ skeletal mineralogy within some-but not all-marine calcifiers will change as atmospheric pCO 2 continues rising as a result of fossil fuel combustion and deforestation. Paleoceanographic reconstructions of seawater Mg/Ca, temperature, and salinity from the Mg/Ca C of well-preserved calcitic marine fossils may also be improved by accounting for the effects of paleo-atmospheric pCO 2 on skeletal Mg-fractionation.

From the * Manchester Heart Centre, Manchester Royal Infirmary, Manchester, M13 9WL, United Kingdom, and † Imperial College London, London, SW7 2AZ, United Kingdom.

The effects of ozone and chlorine dioxide on the aquatic natural organic matter (NOM) were studied. The natural as well as oxidised organic matter in aerated and sand filtered water were fractionated using XAD, anion-exchange, and... more

The effects of ozone and chlorine dioxide on the aquatic natural organic matter (NOM) were studied. The natural as well as oxidised organic matter in aerated and sand filtered water were fractionated using XAD, anion-exchange, and cation-exchange resins procedure into humic acid, hydrophobic acids and neutrals, and hydrophilic acids, bases and neutrals. The main NOM components were hydrophobic, while oxidation with both ozone and chlorine dioxide increased the proportion of hydrophilic fractions. High-pressure size exclusion chromatography with UV-254 nm and UV-220 nm detection was used to determine the differences between molecular weight distribution of natural and oxidised organic matter fractions. The main purpose of this paper was to compare the reactivity of individual NOM fractions with oxidants in order to compare the productivity of biodegradable by-products after oxidation with chlorine dioxide and ozone. The quantity as well as the quality of by-products were analysed by means of ion and gas chromatography. r

Vacuum pyrolysis of 100 g of lignin derived from steam explosion of wood yielded 42.7% oil, 38.0% charcoal, 10.0% gas and 9.3% pyrolytic water (wt. %, moisture and ash-free basis) at 465°C and below 2 kPa absolute pressure. The pyrolysis... more

Vacuum pyrolysis of 100 g of lignin derived from steam explosion of wood yielded 42.7% oil, 38.0% charcoal, 10.0% gas and 9.3% pyrolytic water (wt. %, moisture and ash-free basis) at 465°C and below 2 kPa absolute pressure. The pyrolysis oil was fractionated into eight fractions, Fl-F8. Fl and F2 were mainly hydrocarbons and accounted for 3.4% of the anhydrous oil. F3 to F7 were mainly mono and diphenols and represented 41.6% of the anhydrous oil. F8 had very low GC/MS response due to its low volatility and/or high polarity. It may be possible to use directly fractions F3 to F7 in phenolic resin formulation.

A novel pharmacological mechanism of action for the anxiolytic botanical Melissa officinalis L. (lemon balm) is reported. The methanol extract was identified as a potent in vitro inhibitor of rat brain GABA transaminase (GABA-T), an... more

A novel pharmacological mechanism of action for the anxiolytic botanical Melissa officinalis L. (lemon balm) is reported. The methanol extract was identified as a potent in vitro inhibitor of rat brain GABA transaminase (GABA-T), an enzyme target in the therapy of anxiety, epilepsy and related neurological disorders. Bioassay-guided fractionation led to the identification and isolation of rosmarinic acid (RA) and the triterpenoids, ursolic acid (UA) and oleanolic acid (OA) as active principles. Phytochemical characterization of the crude extract determined RA as the major compound responsible for activity (40% inhibition at 100 µg/mL) since it represented approximately 1.5% of the dry mass of the leaves. Synergistic effects may also play a role. Copyright © 2009 John Wiley & Sons, Ltd.

The bio-oil used in this study was produced from the feed stock such as wheat hemlock. Therefore, in order to investigate the composition of bio-oil and its feedstock, initially the physical and chemical characterisation of wheat-hemlock... more

The bio-oil used in this study was produced from the feed stock such as wheat hemlock. Therefore, in order to investigate the composition of bio-oil and its feedstock, initially the physical and chemical characterisation of wheat-hemlock biomass was carried out using bomb calorimeter, XRD, TGA, ICP-MS, CHNSO, FT-IR and HPLC. The biomass was then subjected to fast pyrolysis process to obtained bio-oil, which is used both as an energy source and a feedstock for chemical production. The physical and chemical characterisation of bio-oil was carried out using bomb calorimeter, CHNSO, FT-IR, GC-FID and GC/MS to check for its composition. During the analysis it was observed that the bio-oil under study contained 59 % water with mixtures of hydrocarbons, fatty acids, phenols and its derivatives. Due to this high percentage of water in biooil, it forms azeotrope with phenolic and acidic compounds. Therefore the major objective of the present study was to isolate the valuable organic fraction of the bio-oil using supercritical CO 2 technique. Three fractions were separated at pressure of 10, 25 and 30 MPa at 40 o C for 2 hours and the yield of the extracts was found to be 3.3%, 13.2% and 15.2% respectively. The remaining waxy residue left after extraction mostly contained water. The bio-oil fractions obtained after extraction were characterised for its composition. The fractions collected at 10-25 MPa pressure were enriched with phenol derivatives and fraction obtained at 30 MPa contained improved percentage of fatty acid. These results indicate that the supercritical CO 2 is a suitable process for selective separation of valuable chemicals from azeotrope.

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Deep eutectic solvents (DESs) are a relatively new topic in science. Their usage is not yet clearly defined, and the areas in which DESs may be applied are constantly growing. A simple and clean fractionation of the main components of... more

Deep eutectic solvents (DESs) are a relatively new topic in science. Their usage is not yet clearly defined, and the areas in which DESs may be applied are constantly growing. A simple and clean fractionation of the main components of biomass represents a very important step in creating a clean, renewable carbon economy. A major challenge is the use of DESs for fractionation of biomass components at lower temperatures, without the use of expensive raw materials. In this work, wheat straw was pretreated with six different DES systems composed of choline chloride with urea (1:2), malonic acid (1:1), lactic (1:9; 1:10), malic (1:1), and oxalic acid (1:1). The pretreated biomass was characterized in terms of lignin content, ash, and holocellulose. A deep eutectic solvent, composed of choline chloride and oxalic acid, was found to produce the best delignification results. The solvents are not selective in the process of delignification.

We present a novel method for nitrogen and oxygen natural isotopic abundance analysis of nitrate and nitrite of seawater and freshwater at environmental concentrations. The method involves the reduction of nitrate to nitrite using spongy... more

We present a novel method for nitrogen and oxygen natural isotopic abundance analysis of nitrate and nitrite of seawater and freshwater at environmental concentrations. The method involves the reduction of nitrate to nitrite using spongy cadmium with further reduction to nitrous oxide using sodium azide in an acetic acid buffer. For separate nitrite analysis, the cadmium reduction step is simply bypassed. Nitrous oxide is purged from the water sample and trapped cryogenically using an automated system with subsequent release into a gas chromatography column. The isolated nitrous oxide is then analyzed on a continuous flow isotope ratio mass spectrometer via an open split. This paper describes the basic protocol and reaction conditions required to obtain reproducible natural abundance level nitrogen and oxygen isotopic ratios from nitrate, nitrite, or both, and the results obtained to support these conclusions. A standard deviation less than 0.2‰ for nitrogen and 0.5‰ for oxygen was found for nitrate samples ranging in concentration from 40 to 0.5 µM (better for nitrite), with a blank of 2 nmol for 50-mL samples. Nitrogen and oxygen isotopic fractionation and oxygen atom exchange were consistent within each batch of analysis. There was no interference from any seawater matrixes. Only one other method published to date can measure the nitrate oxygen isotopic abundance in seawater and none that do so for nitrite alone in the presence of nitrate. This method may prove to be simpler, faster, and obtain isotopic information for lower concentrations of nitrate and nitrite than other methods.

On estime que 22 à 25 millions de litres de plasma sont fractionnés au monde annuellement par environ 70 fractionneurs, privés ou publics, localisés principalement dans les pays industrialisés et possédant une capacité comprise entre 50... more

On estime que 22 à 25 millions de litres de plasma sont fractionnés au monde annuellement par environ 70 fractionneurs, privés ou publics, localisés principalement dans les pays industrialisés et possédant une capacité comprise entre 50 000 à trois millions de litres. Dans un marché des produits plasmatiques (« médicaments dérivés du sang ») qui s'est globalisé, ce secteur a connu une phase de consolidation industrielle se traduisant par des regroupements-acquisitions, et par la disparition de certains petits centres en Europe. Par ailleurs, une quinzaine de pays sont impliqués actuellement dans des contrats à façon pour assurer leur approvisionnement en produits fractionnés. Plus de la moitié du volume de plasma pour fractionnement est collecté par plasmaphérèse automatisée, le reste provenant de la collecte de sang total. De par le monde, le plasma destiné au fractionnement doit être préparé en suivant des procédures de collecte bien documentées et doit répondre à des critères de qualité très réglementés par les autorités de tutelle et par les fractionneurs. Les technologies de fractionnement, si elles reposent encore sur des étapes de précipitation à l'éthanol, se sont perfectionnées par l'introduction de procédés de purification chromatographique modernes et par des traitements d'inactivation et d'élimination virales qui assurent la fabrication d'une gamme de produits de qualité et sûrs. La sécurité vis-à-vis du risque de transmission du variant de la maladie de Creutzfeldt-Jakob (vMCJ) semble être apportée, d'après les données scientifiques actuelles, par une marge d'élimination suffisante grâce à l'élimination de l'agent infectieux lors de certaines étapes de fractionnement. Le produit phare du fractionnement est actuellement l'immunoglobuline G intraveineuse. L'approvisionnement en produits plasmatiques (tout particulièrement les fractions coagulantes et l'immunoglobuline) à un prix abordable et en quantité suffisante à l'échelle mondiale demeure problématique ; le problème reste particulièrement entier dans les pays en voie de développement, l'accroissement de l'usage de facteur VIII recombinant dans les pays riches n'a pas modifié cette donne et a entraîné une augmentation du prix des fractions destinées au monde en développement. Le fractionnement plasmatique a, au cours de ces dernières années, accompli une mutation technologique et scientifique considérable, et demeure essentiel à la fabrication de nombreux médicaments. # 2007 Elsevier Masson SAS. Tous droits réservés.

Phosphorus (P) is an essential element in crop nutrition, which can be growth limiting or an environmental contaminant, if present in excess. Tillage practices have a direct effect on the behavior and availability of soil P. Sorption and... more

Phosphorus (P) is an essential element in crop nutrition, which can be growth limiting or an environmental contaminant, if present in excess. Tillage practices have a direct effect on the behavior and availability of soil P. Sorption and availability of various P forms were evaluated in an incubation-fractionation study of three soils, a Typic Paleudults (CR soil) and two Cerrado Oxisols (Latossolo Vermelho-Amarelo [LVA] and Latossolo Vermelho [LV]) with distinct biogeochemical characteristics and tillage management history. Phosphate and myo-inositol hexakisphosphate (mIPH) were strongly sorbed by the soils. Maximum adsorption capacities (S max) were 2.2-6.9, 3.3-7.8, and 1.6-19.8 mmol kg − 1 for phosphate in the 0-40 cm depths of the CR, LV, and LVA soils, respectively. For mIPH, S max were 1.2-3.7, 3.7-5.5, and 4.6-5.2 mmol kg − 1. Saturation indices reflected the long-term effect of repeated manure applications on the Paleudults and the near saturation of its P holding capacity, in contrast to the recently cultivated Cerrado soils. Tillage method appeared to have altered P retention characteristics of the near-surface zone very slightly, while increases in ligandexchangeable (EEP i) and enzyme-labile organic P (EDTA-PHP) forms were observed in no-till Oxisols. In the Paleudults, added manure P increased bioactive P fractions and P saturation of no-till near-surface soil zone. Estimates of all bioactive P fractions using the ligand-based enzymatic assay showed it to be an effective method for assessing P availability in soil and developing sustainable P management strategies, particularly in Cerrado Oxisols that were low in organic matter while having an extensive P-fixing capacity.

Ultra-filtration (UF) provides a new way of generating narrow bands of sample in the fractionation of coal and petroleum-derived liquids. It allows larger quantities of high-mass fractions to be recovered, making more detailed... more

Ultra-filtration (UF) provides a new way of generating narrow bands of sample in the fractionation of coal and petroleum-derived liquids. It allows larger quantities of high-mass fractions to be recovered, making more detailed investigations possible, through the use of techniques requiring larger amounts of sample. In this work, UF-separated fractions have been used to study molecular mass distributions of a coal tar pitch, used as laboratory standard. The pitch was fractionated by solvent solubility into three fractions. These were further fractionated by ultra-filtration, using membranes specific to protein molecular sizes classed as ''1 kDa", ''5 kDa", ''10 kDa" and ''100 kDa". Planar chromatography was used as a tertiary fractionation method, to subdivide the UF-fractions. The various fractions were examined by size exclusion chromatography (SEC), UV-fluorescence spectroscopy and laser desorption-mass spectrometry (LD-MS). There was good agreement between mass estimates based on SEC and LD-MS of the smaller UF-fractions, with evidence for the presence of material with molecular masses ranging between 800 and 10,000 u. Examining the largest UF fractions of the pitch-pyridine-insoluble sample also gave clear evidence for material with molecular masses above 10,000 u. Taken together, however, the LD-MS data showed progressively diminishing differences, as the sizes of the UF membranes, and the likely molecular masses of the sample fractions, increased. One likely explanation is incomplete sampling during the laser desorption procedure. The evidence suggests that the upper mass limit detectable for these and similar samples by LD-MS has been reached. Despite these reservations, LD-MS appears as the best method to date, for investigating the mass ranges of samples derived from coal tar pitch and heavy petroleum fractions.

Oil deodorizer distillate (DOD), a byproduct from the soybean oil refining process, is rich in valuable compounds, such as natural tocopherols (vitamin E) and sterols. With the aim of concentrating tocopherols from methyl esterified DOD... more

Oil deodorizer distillate (DOD), a byproduct from the soybean oil refining process, is rich in valuable compounds, such as natural tocopherols (vitamin E) and sterols. With the aim of concentrating tocopherols from methyl esterified DOD with supercritical CO 2 , a semi-continuous countercurrent process was developed using a fractionation column with a height of 2.4 m, an inner diameter of 20 mm, and a total volume of 750 mL. Operation parameters, pressure, the ratio of solvent to feed, and temperature of the column were investigated. The experimental results indicated that supercritical CO 2 effectively extracts fatty acid methyl esters at 16 MPa with a column temperature gradient of 313-348 K. By increasing pressure, natural tocopherols (>50%) can be obtained with high recovery (>80%). It is concluded that supercritical CO 2 fractionation is technically feasible for concentrating natural tocopherols from methyl esterified DOD.

ABS¹RAC¹ A sequential chemical extraction method for the determination of the geochemical fractionation of Am, Pu, and º was evaluated rigorously on a single marine sediment standard (IAEA-135). Partitioning of actinides was operationally... more

ABS¹RAC¹ A sequential chemical extraction method for the determination of the geochemical fractionation of Am, Pu, and º was evaluated rigorously on a single marine sediment standard (IAEA-135). Partitioning of actinides was operationally defined for five reagent fractions and stable element analyses (Al, Ca, Fe, Mn, ¹i, etc.) were performed to assist in establishing the phase specificity of the extractions. ¹he method produces, in general, results that agree to within a one standard deviation interval for replicate measurements for each fraction. Actinide readsorption, examined by a double-spiking technique, was found to be significant in some cases. Ethylenediamine-tetraacetic acid (ED¹A) was examined as a hold-back reagent to lessen the effect of readsorption but seriously compromised the phase selectivity of the extractants. In addition, the use of NaOCl for the destruction of organic matter was found to dissolve carbonates out of sequence and is not recommended for carbonate-bearing materials.

Patients in every country should have access to quality blood products. National health authorities play a critical role in ensuring that patients' needs are met with safe and cost-effective products. Fractionated plasma products, as... more

Patients in every country should have access to quality blood products. National health authorities play a critical role in ensuring that patients' needs are met with safe and cost-effective products. Fractionated plasma products, as other blood products, are essential therapeutics used in the prevention, management, and treatment of life-threatening conditions resulting from trauma, metabolic congenital deficiencies, immunological disorders or infections. A few high development index (HDI) countries in the region have sufficient access to a broad portfolio of plasma products (coagulation factors, immunoglobulin, albumin) through domestic (e.g. Australia, Japan, Korea) or contract (e.g. Singapore, New Zealand) plasma fractionation programmes. China is gradually establishing a modern plasma fractionation industry. Other countries face plasma product shortages leading to inappropriate clinical use of plasma for transfusion and of non-virally inactivated cryoprecipitate, and ultimately to inappropriate treatment of patients.

Due to rapid urbanisation and scarcity of land, most of the urban parks and recreational areas in Hong Kong are built close to major roads or industrial areas, where they are subject to many potential pollution sources, including vehicle... more

Due to rapid urbanisation and scarcity of land, most of the urban parks and recreational areas in Hong Kong are built close to major roads or industrial areas, where they are subject to many potential pollution sources, including vehicle exhaust and industrial emissions. An extensive soil survey was conducted in urban parks of Hong Kong to study the current conditions of heavy metals contamination in soils. Soil samples and associated street dusts were collected from more than 60 parks and public amenity areas in old urban districts, industrial areas and New Towns of the territory. Soils were also sampled in the remote country parks to establish the baseline conditions. The total concentrations of heavy metals and major elements in the samples were determined. The results indicate that urban soils in Hong Kong have elevated concentrations of Cd, Cu, Pb and Zn. The parks with high metal concentrations are located in old urban commercial districts and industrial areas, indicating that the major contamination sources in these soils are traffic emissions and industrial activities. In addition, the application of Cd containing phosphate fertilizers may be an important source of Cd in urban park soils. The street dusts have highly elevated Zn concentration, particularly along the main trunk roads. The high Zn content in the street dusts may come from traffic sources, especially vehicle tyres. Selective soil and road dust samples were also analysed for potential chemical speciation by a sequential chemical extraction method. The chemical partitioning results show that Pb and Zn are mainly in the carbonate/adsorbed and Fe–Mn oxide phases, while Cu is largely associated with the organic and sulphide fractions. The high exchangeable Cd in urban soils and high concentration of Zn in street dusts need further investigation for their ecological and health implications.

The distribution of Si, Al, Fe, Mn, Cu, Zn, Ni and Cr in different grain-size fractions and geochemical association of Fe, Mn, Cu and Zn with <63-μm size fraction of bed sediments of Damodar River has been studied. In general,... more

The distribution of Si, Al, Fe, Mn, Cu, Zn, Ni and Cr in different grain-size fractions and geochemical association of Fe, Mn, Cu and Zn with <63-μm size fraction of bed sediments of Damodar River has been studied. In general, concentrations of heavy metals tend to increase as the size fractions get finer. However at two sites, near mining areas, the coarser particles show similar or even higher heavy metal concentrations than finer ones. The higher residence time and/or presence of coarser particles from mining wastes are possibly responsible for higher metal content in the coarser size fractions. The chemical fractionation study shows that lithogenic is the major chemical phase for heavy metals. Fe and Mn are the major elements of the lithogenic lattice, constituting 34–63% and 22–59%, respectively, of total concentrations. Fe-Mn oxide and organic bound fractions are significant phases in the non-lithogenic fraction. The carbonate fraction is less significant for heavy metal scavenging in the present environment and shows the following order of abundance Zn>Cu>Mn>Fe. The exchangeable fraction of the Damodar sediments contains very low amounts of heavy metals suggesting poor bioavailability of metals.

Liquid-liquid extraction was used in order to recover phenolic compounds from olive mill wastewater (OMWW), a polluting by-product of olive oil production process, and the extraction parameters have been optimized. HPLC analysis showed... more

Liquid-liquid extraction was used in order to recover phenolic compounds from olive mill wastewater (OMWW), a polluting by-product of olive oil production process, and the extraction parameters have been optimized. HPLC analysis showed that hydroxytyrosol is the most abundant biophenol in ethyl acetate extracts from an acidified OMWW. Many other biophenols (tyrosol, caffeic acid, vanillic acid, verbascoside, luteolin-7-glucoside, dialdehydic form of decarboxymethyl oleuropein aglycon, ligstroside, luteolin) were identified.

A literature review on the determination of trace elements in crude oil and heavy molecular mass fractions (saturates, aromatics, resins and asphaltenes) by ICP-MS, ICP OES and AAS is presented. Metal occurrences, forms and distributions... more

A literature review on the determination of trace elements in crude oil and heavy molecular mass fractions (saturates, aromatics, resins and asphaltenes) by ICP-MS, ICP OES and AAS is presented. Metal occurrences, forms and distributions are examined as well as their implications in terms of reservoir geochemistry, oil refining and environment. The particular analytical challenges for the determination of metals in these complex matrices by spectrochemical techniques are discussed. Sample preparation based on ashing, microwave-assisted digestion and combustion decomposition procedures is noted as robust and long used. However, the introduction of non-aqueous solvents and micro-emulsions into inductively coupled plasmas is cited as a new trend for achieving rapid and accurate analysis. Separation procedures for operationally defined fractions in crude oil are more systematically applied for the observation of metal distributions and their implications. Chemical speciation is of growing interest, achieved by the coupling of high efficiency separation techniques (e.g., HPLC and GC) to ICP-MS instrumentation, which allows the simultaneous determination of multiple organometallic species of geochemical and environmental importance.

Miscanthus sinensis L. was fractionated by different reagents (ethanol, soda and soda-ethanol) in order to obtain cellulose, hemicelluloses and lignin. Characterization of original M. sinensis fibres (66.6% holocellulose, 36.1%... more

Miscanthus sinensis L. was fractionated by different reagents (ethanol, soda and soda-ethanol) in order to obtain cellulose, hemicelluloses and lignin. Characterization of original M. sinensis fibres (66.6% holocellulose, 36.1% ␣-cellulose, and 15.5% lignin) was done and compared with other biomass species chemical composition (alternative raw materials, agriculture residues, coniferous and leafy plants). Obtained solid fractions were chemically characterized and compared with solid fractions from other biomass products (palm oil empty fruit bunches (EFB) and rice straw) generated by similar fractionation processes (soda and organosolv). Soda process produced the solid fraction with the highest content in ␣-cellulose and lowest content in lignin revealing a strong fractionation effect. On the contrary, soda-ethanol process was found to present low fractionation capability. Obtained cellulose samples were characterized by FTIR to complete the chemical structure analysis. Lignin samples isolated from the liquid fractions were submitted to FTIR, 1 H NMR, GPC, DSC and TGA in order to suggest suitable applications for the products based on their properties.

This paper reviews the experimental procedures of the Gas Chromatography-Mass Spectrometry (GC-MS) technique. The objectives of this study are to present a step-by-step procedure involved in the GC-MS analysis and interpretations of the... more

This paper reviews the experimental procedures of the Gas Chromatography-Mass Spectrometry (GC-MS) technique. The objectives of this study are to present a step-by-step procedure involved in the GC-MS analysis and interpretations of the resulting data both qualitatively and quantitatively, and to identify the possible sources of analytical errors that may be encountered by young inexperienced organic geochemists. The overall process encompasses ultrasonic solvent extraction, fractionation and GC-MS analysis itself. The qualitative and quantitative information obtained from the GC-MS interpretations when integrated together is capable of giving us an insight into the source or origin, depositional environment and level thermal maturity of the analysed sample. The possible sources of analytical errors may include contamination, measurement errors, mechanical/instrumental errors, fractionation errors, and loading errors on the GC. Analytical geochemists must therefore be aware of these errors among others in order to minimise them to the reasonable level. It is recommended that, if weak signals result from the GC-MS analysis of a fraction, such a fraction should be prepared in higher concentration and re-run using selected ion monitoring (SIM) mode so as to enhance signal to noise ratio, and that the GC-MS data should always be interpreted with GC-MS softwares with biomarkers definitions in order to obtain more reliable and robust interpretations.

Studies were conducted on properties of oil extracted from raspberry seeds. Oil yield from the seed was 10.7%. Physicochemical properties of the oil include: saponi®cation number 191; diene value 0.837; p-anisidine value 14.3; peroxide... more

Studies were conducted on properties of oil extracted from raspberry seeds. Oil yield from the seed was 10.7%. Physicochemical properties of the oil include: saponi®cation number 191; diene value 0.837; p-anisidine value 14.3; peroxide value 8.25 meq/kg; carotenoid content 23 mg/100 g; and viscosity of 26 mPa.s at 25 C. Raspberry seed oil showed absorbance in the UV-B and UV-C ranges with potential for use as a broad spectrum UV protectant. The seed oil was rich in tocopherols with the following composition (mg/100 g): a-tocopherol 71; g-tocopherol 272; d-tocopherol 17.4; and total vitamin E equivalent of 97. The oil had good oxidation resistance and storage stability. Lipid fractionation of crude raspberry seed oil yielded 93.7% neutral lipids, 3.5% phospholipids, and 2.7% free fatty acids. The main fatty acids of crude oil were C18:2 n-6 (54.5%), C18:3 n-3 (29.1%), C18:1 n-9 (12.0%), and C16:0 (2.7%). The ratio of fatty acids, polyunsaturates to monounsaturates to saturates varied depending on lipid fraction. Polymorphic changes were observed in thermal properties of raspberry seed oil. #

ABSTRACT: High-oleic palm oil (HOPO) with an oleic acid content of 59.0% and an iodine value (IV) of 78.2 was crystallized in a 200-kg De Smet crystallizer with a predetermined cooling program and appropriate agitation. The slurry was... more

ABSTRACT: High-oleic palm oil (HOPO) with an oleic acid content of 59.0% and an iodine value (IV) of 78.2 was crystallized in a 200-kg De Smet crystallizer with a predetermined cooling program and appropriate agitation. The slurry was then fractionated by means of dry fractionation at 4, 8, 10, 12, and 15 °C. The oil and the fractionated products were subjected to physical and chemical analyses, including fatty acid composition, triacylglycerol and diacylglycerol composition, solid fat content, cloud point, slip melting point, and cold stability test. Fractionation at 15 °C resulted in the highest olein yield but with minimal oleic acid content. Due to the enhanced unsaturation of the oil, fractionation at relatively lower crystallization temperature showed a considerable effect on fatty acid composition as well as triacylglycerol and diacylglycerol composition of liquid fractions compared to higher crystallization temperature. The olein and stearin fractionated at 4 °C had the best cold stability at 0 °C and sharper melting profile, respectively.

The end of an orogenic Wilson cycle corresponds to amalgamation of terranes into a Pangaea and is marked by widespread magmatism dominated by granitoids. The post-collision event starts with magmatic processes still influenced by... more

The end of an orogenic Wilson cycle corresponds to amalgamation of terranes into a Pangaea and is marked by widespread magmatism dominated by granitoids. The post-collision event starts with magmatic processes still influenced by subducted crustal materials. The dominantly calc-alkaline suites show a shift from normal to high-K to very high-K associations. Source regions are composed of depleted and later enriched orogenic subcontinental lithospheric mantle, affected by dehydration melting and generating more and more K-and LILE-rich magmas. In the vicinity of intra-crustal magma chambers, anatexis by incongruent melting of hydrous minerals may generate peraluminous granitoids bearing mafic Ž . enclaves. The post-collision event ends with emplacement of bimodal post-orogenic PO suites along transcurrent fault Ž . zones. Two suites are defined, i the alkali-calcic monzonite-monzogranite-syenogranite-alkali feldspar granite association w x w x Ž . characterised by biotiteq plagioclase fractionation and moderate LILE q HFSE enrichments and ii the alkaline w x monzonite-syenite-alkali feldspar granite association characterised by amphiboleq alkali feldspar fractionation and displaying two evolutionary trends, one peralkaline with sodic mafic mineralogy and higher enrichments in HFSE than in LILE, and the other aluminous biotite-bearing marked by HFSE depletion relative to LILE due to accessory mineral precipitation. Alkali-calcic and alkaline suites differ essentially in the amounts of water present within intra-crustal magma chambers, promoting crystallisation of various mineral assemblages. The ultimate enriched and not depleted mantle source is identical for the two PO suites. The more primitive LILE and HFSE-rich source rapidly replaces the older orogenic mantle source during lithosphere delamination and becomes progressively the thermal boundary layer of the new lithosphere. Present rock compositions are a mixture of major mantle contribution and various crustal components carried by F-rich aqueous fluids circulating within convective cells created around magma chambers. In favourable areas, PO suites pre-date a new orogenic Wilson cycle. q 1998 Elsevier Science B.V. All rights reserved. 0024-4937r98r$ -see front matter q 1998 Elsevier Science B.V. All rights reserved.

Balancing ruminant diets for appropriate levels and types of dietary carbohydrates (CHO) is necessary to maximize production while assuring the health of the animals. Several feed fractions (i.e., volatile fatty acids (VFA), lactate,... more

Balancing ruminant diets for appropriate levels and types of dietary carbohydrates (CHO) is necessary to maximize production while assuring the health of the animals. Several feed fractions (i.e., volatile fatty acids (VFA), lactate, sugars, starch) are now being measured in some commercial feed laboratories and this information may assist in better formulating diets. A CHO fractionation scheme based on ruminal degradation characteristics needed for nutritional models is described and its impact on predictions with the Cornell Net Carbohydrate and Protein System (CNCPS) is assessed. Dietary CHO are divided into eight fractions: the CA1 is volatile fatty acids (VFA), CA2 is lactic acid, CA3 is other organic acids, CA4 is sugars, CB1 is starch, CB2 is soluble fiber, CB3 is available neutral detergent fiber (NDF), and CC is unavailable NDF. A Monte Carlo analysis was conducted with an example lactating dairy cow ration to compare the original CNCPS CHO scheme (CA = sugars and organic acids, CB1 = starch and soluble fiber, CB2 = available NDF, CC = unavailable NDF) with the developed CHO scheme. A database was used to obtain distributions and correlations of the feed inputs used in the schemes for the ingredients of the ration (corn and grass silages, high moisture Abbreviations: AA, amino acids; aNDR, NDF assayed with amylase and without sodium sulfite; CHO, carbohydrates; CNCPS, Cornell Net Carbohydrate and Protein System; CPM, Cornell-Penn-Miner Net Carbohydrate and Protein System; DM, dry matter; EE, ether extract; FC, fiber carbohydrates; HMCG, high moisture corn grain; ME, metabolizable energy; MP, metabolizable protein; ND, neutral detergent; NDF, neutral detergent fiber; NDICP, neutral detergent insoluble CP; NFC, non-fiber carbohydrates; R.M.S.E., root mean standard error; VFA, volatile fatty acids; Y g , maximum rumen microbial growth yield * Corresponding author. soluble fiber, lactic acid, sugar, NDF, starch, and total non-fiber carbohydrates (NFC). Use of the expanded scheme in the CNCPS decreased the microbial CP production, which was sensitive (standard regression coefficient in parenthesis) to corn silage starch (0.55), grass silage NDF rate (0.46), high moisture corn grain starch rate (0.44), and corn silage NDF rate (0.33). Predicted ruminal NFC digestibility remained similar. The expanded CHO scheme provides a more appropriate feed description to account for variation in changes in silage quality and diet NFC composition. However, to fully account for differences in feed CHO utilization, further improvements in the methodology used to estimate the fractions and their corresponding degradation rates, inclusion of dietary factors in dry matter intake predictions, and prediction of ruminal VFA production and pH are necessary.

A simple and fast fractionation method was developed to obtain carbohydrate-free lignin with well-defined characteristics, such as narrowly distributed molecular weights and a tunable chemical structure for specific applications. In this... more

A simple and fast fractionation method was developed to obtain carbohydrate-free lignin with well-defined characteristics, such as narrowly distributed molecular weights and a tunable chemical structure for specific applications. In this study, an industrial softwood kraft lignin and a hardwood CELF lignin (coproduct lignin obtained from cosolvent enhanced lignocellulosic fractionation pretreatment) were dissolved in acetone−methanol and tetrahydrofuran−methanol cosolvents, respectively. Hexane was applied as the antisolvent for sequential precipitation of both lignin preparations. A thorough characterization including various NMR techniques (31 P, quantitative 13 C, and 2D-HSQC), GPC, DSC and TGA was conducted to correlate the molecular weight of obtained lignin fractions with their structural features including distributions of aliphatic and phenolic hydroxyl groups and relative abundance of interunit linkages. It was found that approximately 10% of the softwood kraft lignin was lignin carbohydrate complexes, and the latter one could be removed efficiently by decreasing polarity of the cosolvent.

This paper uses a previously developed systematic procedure to obtain design targets for heat integration in conventional crude fractionation units that use prefractionation columns or preflash drums. It is shown that, under the same high... more

This paper uses a previously developed systematic procedure to obtain design targets for heat integration in conventional crude fractionation units that use prefractionation columns or preflash drums. It is shown that, under the same high product yield conditions, prefractionation or preflashing followed by a conventional unit are not as energy efficient as straight conventional crude units. This is in great part due to the loss of the carrier effect that light components have in separating heavy gas-oil fractions in the flash zone. Such a carrier effect is discussed. In addition, if one accepts the yield of atmospheric gas oil to be smaller, then these prefractionation/ preflash options consume less energy.

Cellular lipids frequently co-purify with lipid binding proteins isolated from tissue extracts or heterologous host systems and as such hinder in vitro ligand binding approaches for which the apo-protein is a prerequisite. Here we present... more

Cellular lipids frequently co-purify with lipid binding proteins isolated from tissue extracts or heterologous host systems and as such hinder in vitro ligand binding approaches for which the apo-protein is a prerequisite. Here we present a technique for the complete removal of unesterified fatty acids, phospholipids, steroids and other lipophilic ligands bound to soluble proteins, without protein denaturation. Peroxisome proliferator activated receptor ␥ ligand binding domain and intracellular fatty acid binding proteins were expressed in an Escherichia coli host and completely delipidated by hydrophobic interaction chromatography using phenyl sepharose. The delipidation procedure operates at room temperature with complete removal of bound lipids in a single step, as ascertained by mass spectrometry analysis of organic solvent extracts from purified protein samples. The speed and capacity of this method makes it amenable to scale-up and high-throughput applications. The method can also easily be adapted for other lipid binding proteins that require delipidation under native conditions.

Refined palm olein was dry fractionated via three different cooling programs on laboratory-scale fractionation equipment. The enrichment and depletion of the main triacylglycerols in the liquid and solid phase was plotted as a function of... more

Refined palm olein was dry fractionated via three different cooling programs on laboratory-scale fractionation equipment. The enrichment and depletion of the main triacylglycerols in the liquid and solid phase was plotted as a function of the crystallization degree of the oil. It was shown that for the given conditions and palm olein composition, the initial crystals mainly consisted of PPP, diacylglycerols, POP and PLP. At higher crystallization degrees, a sharp viscosity increase in the crystal suspension was primarily related to an obvious decrease of POP but also of POS in the recovered superolein, while the general crystallization rate of the system remained unchanged. Rather than a change in crystallization rate of POP, a change in the ratio between the crystallizing monounsaturated triacylglycerols is linked with the high viscosity of the crystal slurry. For a comparable degree of crystallization, the superolein of the more viscous crystal slurry, obtained through a membrane press filtration up to 15 bar, was more unsaturated than the superolein filtered from the less viscous slurry. Consequently, the high unsaturation in the corresponding soft palm mid fraction is only the result of an incomplete phase separation, and not due to an increased intersolubility of unsaturated triacylglycerols in the crystals.

As are traditional fractionation technologies, static dry fractionation is a highly reliable technology for the consistent production of good-quality palm kernel stearin (PKS) for use as cocoa butter substitute (CBS) after total... more

As are traditional fractionation technologies, static dry fractionation is a highly reliable technology for the consistent production of good-quality palm kernel stearin (PKS) for use as cocoa butter substitute (CBS) after total hydrogenation. A new process route now permits the production of unhardened yet high-quality CBS. Also an increase in total stearin yield can be achieved, via a successful refractionation of palm kernel olein. DSC analysis together with pilot static fractionation trials on the palm kernel olein indicates that a cooling water temperature that is too low (e.g., 17°C) may result in the quick formation of unstable crystals that are possibly later converted to a more stable form. The resulting mixture of crystals with a possibly different polymorphic structure is easily squeezed through the filter cloth during filtration, whereas a slower, but more homogeneous co-crystallization occurs at higher temperature (18°C or higher) and results in a much more stress-resistant slurry. Polarized light microscopy analysis confirmed that crystal size is not the only determining factor for a successful filtration. The total two-stage static fractionation of palm kernel oil (PKO) [iodine value (IV) 18] on a pilot scale results in the following three end products: PKS IV 5 (yield: 29%, for direct use as CBS), PK olein IV 27 (yield: 58%), and PKS IV 7 (yield: 13% for use as CBS after full hydrogenation). The unhardened PKS IV 5 has outstanding melting and crystallization properties, comparable to traditional hydrogenated stearin fractions. Therefore, rather than the higher stearin yield, the reduced hydrogenation capacity is most probably the most important benefit of the two-stage static fractionation process.

The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of... more

The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. "green") products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Approach: The technical approach for this quarter included the fractionation of extracts prepared from several varieties of pepper plants, and using several solvents, by high performance liquid chromatography (HPLC). A preliminary determination of antimicrobial activities of the new extracts and fractions using a growth inhibition assay, and evaluation of the extracts' ability to inhibit biofilm formation was also performed. Results: The analysis of multiple extracts of pepper plants and fractions of extracts of pepper plants obtained by HPLC illustrated that these extracts and fractions are extremely complex mixtures of chemicals. Gas chromatography-mass spectrometry was used to identify the chemical constituents of these extracts and fractions to the greatest degree possible. Conclusions: Analysis of the chemical composition of various extracts of pepper plants has illustrated the complexity of the chemical mixtures present, and while additional work will be performed to further characterize the extracts to identify bioactive compounds the focus of efforts should now shift to an evaluation of the ability of extracts to inhibit corrosion in mixed culture biofilms, and in pure cultures of bacterial types which are known or believed to be important in corrosion.

Aim of the study: This study was designed to investigate the antimicrobial activities of the methanol extracts from the stem bark of Ficus ovata (FOB), fractions (FOB1-6) and compounds isolated following bio-guided fractionation... more

Aim of the study: This study was designed to investigate the antimicrobial activities of the methanol extracts from the stem bark of Ficus ovata (FOB), fractions (FOB1-6) and compounds isolated following bio-guided fractionation [3-friedelanone (1), taraxeryl acetate (2), betulinic acid (3), oleanoïc acid (4), 2-hydroxyisoprunetin (5), 6,7-(2-isopropenyl furo)-5,2,4-trihydroxyisoflavone (6), Cajanin (7) and protocatechuic acid ].

The catalytic cracking of waste cooking palm oil to biofuel was studied over different types of nanocrystalline zeolite catalysts in a fixed bed reactor. The effect of reaction temperature (400-500°C), catalyst-to-oil ratio (6-14) and... more

The catalytic cracking of waste cooking palm oil to biofuel was studied over different types of nanocrystalline zeolite catalysts in a fixed bed reactor. The effect of reaction temperature (400-500°C), catalyst-to-oil ratio (6-14) and catalyst pore size of different nanocrystalline zeolites (0.54-0.80 nm) were studied over the conversion of waste cooking palm oil, yields of Organic Liquid Product (OLP) and gasoline fraction in the OLP following central composite design (CCD). The response surface methodology was used to determine the optimum value of the operating variables for maximum conversion as well as maximum yield of OLP and gasoline fraction, respectively. The optimum reaction temperature of 458°C with oil/catalyst ratio = 6 over the nanocrystalline zeolite Y with pore size of 0.67 nm gave 86.4 wt% oil conversion, 46.5 wt% OLP yield and 33.5 wt% gasoline fraction yield, respectively. The experimental results were in agreement with the simulated values within an experimental error of less than 5%.

Ethnopharmacological relevance: Diabetes is a growing epidemic worldwide, especially among indigenous populations. Larix laricina was identified through an ethnobotanical survey as a traditional medicine used by Healers and Elders of the... more

Ethnopharmacological relevance: Diabetes is a growing epidemic worldwide, especially among indigenous populations. Larix laricina was identified through an ethnobotanical survey as a traditional medicine used by Healers and Elders of the Cree of Eeyou Istchee of northern Quebec to treat symptoms of diabetes and subsequent in vitro screening confirmed its potential. Materials and methods: We used a bioassay-guided fractionation approach to isolate the active principles responsible for the adipogenic activity of the organic extract (80% EtOH) of the bark of Larix laricina. Post-confluent 3T3-L1 cells were differentiated in the presence or absence of the crude extract, fractions or isolates of Larix laricina for 7 days, then triglycerides content was measured using AdipoRed reagent. Results: We identified a new cycloartane triterpene (compound 1), which strongly enhanced adipogenesis in 3T3-L1 cells with an EC 50 of 7.7 M. It is responsible for two thirds of the activity of the active fraction of Larix laricina. The structure of compound 1 was established on the basis of spectroscopic methods (IR, HREIMS, 1D and 2D NMR) as 23-oxo-3␣-hydroxycycloart-24-en-26-oic acid. We also identified several known compounds, including three labdane-type diterpenes , two tetrahydrofuran-type lignans (compounds 5-6), three stilbenes (compounds 7-9), and taxifolin (compound 10). Compound 2 (13-epitorulosol) also potentiated adipogenesis (EC 50 8.2 M) and this is the first report of a biological activity for this compound. Conclusions: This is the first report of putative antidiabetic principles isolated from Larix laricina, therefore increasing the interest in medicinal plants from the Cree pharmacopeia.

This paper presents the development, optimization and validation of a methodology to determine nine key steroid hormones (viz. pregnenolone, progesterone, dehydroepiandrosterone, androstenedione, testosterone, dihydrotestosterone,... more

This paper presents the development, optimization and validation of a methodology to determine nine key steroid hormones (viz. pregnenolone, progesterone, dehydroepiandrosterone, androstenedione, testosterone, dihydrotestosterone, estrone, 17α-estradiol and 17β-estradiol) expressed in the steroidogenesis in biological fluids. The analytical method allows for the determination of steroid hormones in blood plasma and serum down to 0.08-0.16 ng/mL for estrogens, 0.20-0.36 ng/mL for androgens and 0.36-0.43 ng/mL for progestagens. These limits of detection were obtainable using a two-step solid-phase clean-up for fractionation and elimination of interfering lipids (fatty acids, phospholipids, glycerides and sterols) from the steroid hormones. The accuracy of the method was 50-112% in the range 0.10 to 2.00 ng/mL.

The extraction, fractionation, and chromatographic separation of a series of proanthocyanidin monomers and oligomers were facilitated using a flavonoid-rich cell culture of Vaccinium pahalae Skottsberg as the donor tissue. The cell... more

The extraction, fractionation, and chromatographic separation of a series of proanthocyanidin monomers and oligomers were facilitated using a flavonoid-rich cell culture of Vaccinium pahalae Skottsberg as the donor tissue. The cell cultures, after exposure to light, readily accumulated anthocyanin pigments and other flavonoids in relatively large amounts, with minimal concurrent production of pectins, enzymes, and complex sugars produced in field-grown Vaccinium berries. The absence of these interfering compounds greatly simplified the isolation and purification of proanthocyanidins and other phenolic compounds from cell cultures, primarily using vacuum chromatography. Subsequently, the structures and molecular weights of several individual compounds and the general composition of unresolved fractions were established with 1 Hand 13 C-NMR and MS. The initial extract of V. pahalae cell cultures was readily fractionated on silica gel to yield a series of fractions containing proanthocyanidin B-2, a series of increasingly polar proanthocyanidin oligomers ranging from dimers to heptamers largely based on (2)-epicatechin structures (some with A-type linkages), a mixture of E-and Zp-coumaric acid, the corresponding 4-O-glucoside, and other compounds containing E-and Z-p-coumaric acid moieties. Cell culture extracts demonstrated broad antioxidant capacity and significant ability to inhibit tumor promotion in vitro, as indicated in an ornithine decarboxylase assay.

Petroleum migration patterns in the present-day shelf area of the Columbus basin reflect a complex interaction of structural evolution, stratigraphic architecture, and fault-seal behavior. Thermogenic charge access is ultimately... more

Petroleum migration patterns in the present-day shelf area of the Columbus basin reflect a complex interaction of structural evolution, stratigraphic architecture, and fault-seal behavior. Thermogenic charge access is ultimately controlled by the geographic distribution of sandprone carrier beds and how these vertically stacked stratigraphic units relate spatially to one another along their basinal limits. Migration in this system consists of two components, cross-stratal migration through mud-dominated, deep-water (slope and basin floor) sediments followed by horizon-parallel flow along laterally extensive, sand-prone, shelf carrier beds. Thermogenic charge access to any individual sand occurs only in a linear geographic area where that sand is not shielded from vertical migration by stratigraphically older sands.

A scheme is presented for fractionation of wine components and Fe, Cu and Zn determination in different fractions. The charge of the metal species was established using cation and anion exchange separation based on solid phase extraction.... more

A scheme is presented for fractionation of wine components and Fe, Cu and Zn determination in different fractions. The charge of the metal species was established using cation and anion exchange separation based on solid phase extraction. The resin XAD-8 was used for the separation of wine polyphenols in complexes with wine proteins and polysaccharides. Dowex ion exchange resins were used for the separation of cationic and anionic species of Fe, Cu and Zn. Flame atomic absorption spectrometry and electrothermal atomic absorption spectrometry were used off-line for the quantitative determination of metals in the different fractions obtained. ᮊ

in agreement with the ''twisted hairy rope'' proposal for arabinogalactan proteoglycans.