Matrix Concentration for Products

Dietary phytoestrogens are bioactive compounds with estrogenic activity. With the growing popularity of plant-based diets, the intake of phytoestrogen-rich legumes (especially soy) and legume-derived foods has increased. Evidence from preclinical studies suggests these compounds may have an effect on hormones and health, although the results of human trials are unclear. The effects of dietary phytoestrogens depend on the exposure (phytoestrogen type, matrix, concentration, and bioavailability), ethnicity, hormone levels (related to age, sex, and physiological condition), and health status of the consumer. In this review, we have summarized the results of human studies on dietary phytoestrogens with the aim of assessing the possible hormone-dependent outcomes and health effects of their consumption throughout a lifespan, focusing on pregnancy, childhood, adulthood, and the premenopausal and postmenopausal stages. In pregnant women, an improvement of insulin metabolism has been reported in only one study. Sex hormone alterations have been found in the late stages of childhood, and goitrogenic effects in children with hypothyroidism. In premenopausal and postmenopausal women, the reported impacts on hormones are inconsistent, although beneficial goitrogenic effects and improved glycemic control and cardiovascular risk markers have been described in postmenopausal individuals. In adult men, different authors report goitrogenic effects and a reduction of insulin in non-alcoholic fatty liver patients. Further carefully designed studies are warranted to better elucidate the impact of phytoestrogen consumption on the endocrine system at different life stages.

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Aggregation of meso-tetrakis(4-sulfonatophenyl)porphyrin on polyethyleneimine in aqueous solutions and on a glass surface

Journal of Porphyrins and Phthalocyanines ◽

10.1142/s1088424602000531 ◽

2002 ◽

Vol 06 (06) ◽

pp. 431-438 ◽

Cited By ~ 22

Author(s):

Maria Angela Castriciano ◽

Andrea Romeo ◽

Luigi Monsù Scolaro

Keyword(s):

Aqueous Solutions ◽

Fluorescence Emission ◽

Resonance Light Scattering ◽

Glass Substrates ◽

Vis Spectroscopy ◽

The Matrix ◽

J Aggregates ◽

Matrix Concentration ◽

Glass Surfaces ◽

Neutral Conditions

The aggregation behavior of meso-tetrakis(4-sulfonatophenyl)porphyrin, [ H 2( TPPS 4)]4-, in the presence of hydrated polyethyleneimine ( PEI ) in aqueous solutions (1.6 < pH < 7.6) has been investigated. The interaction leads to the formation of a variety of pH dependent species, which have been attributed to porphyrin dimers or small oligomers under neutral conditions and J-aggregates on lowering the pH. The aggregation process follows kinetics typical of self-similar systems whose rates increase steeply on increasing the matrix concentration. This finding could be explained on the basis of an increased availability of binding sites for the growing aggregates. The charged polymer has been used to electrostatically adsorb the porphyrin onto glass substrates affording multilayered films. Our results point to the presence of fully protonated species in the solid state, which rearrange into J-aggregates as a function of pH and water content. The systems in solution and on glass surfaces have been investigated through a combination of UV-vis spectroscopy, fluorescence emission and resonance light scattering techniques.

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Continuous flow fast atom bombardment mass spectrometry of mononucleotides and their metal complexes

Canadian Journal of Chemistry ◽

10.1139/v89-140 ◽

1989 ◽

Vol 67 (5) ◽

pp. 910-920 ◽

Cited By ~ 19

Author(s):

M. J. Bertrand ◽

V. Benham ◽

R. St-Louis ◽

M. J. Evans

Keyword(s):

Mass Spectrometry ◽

Continuous Flow ◽

Fast Atom Bombardment ◽

Aqueous Media ◽

Molecular Ions ◽

Fragment Ions ◽

Low Concentrations ◽

Metal Adducts ◽

Matrix Concentration

The mass spectra of mononucleotides and their metal adducts Na, K, Mg, Ca, Ni, Co, Cu, and Zn of guanosine 5′-monophosphate (5′-GMP) as well as H, Na, and Mg of adenosine 5′-monophosphate (5′-AMP) and H and Ni of inosine 5′-monophosphate (5′-IMP) have been obtained in low concentrations of matrix in water using continuous-flow fast atom bombardment. The results indicate that this technique is suitable for the analysis of these complexes in aqueous media and yields spectra that are highly characteristic of the compounds analyzed. Parent-molecular ions and structurally significant fragment ions are observed for all compounds studied and the different binding sites for the metal on the nucleotides can be isolated from the fragment ions. Experimental parameters influencing the quality of the spectra such as flow rate, matrix concentration, matrix nature, and analyte concentration have been studied and optimized. For the thirteen compounds studied, it appears that continuous-flow FAB is superior to conventional FAB and that good quality spectra can be obtained with as little as 0.5% of added matrix thus minimizing spectral interferences. Keywords: continuous flow FAB, FAB MS, mass spectrometry, nucleotides, metal-nucleotides.

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Lignocellulosic Composites Prepared Utilizing Aqueous Alkaline/Urea Solutions with Cold Temperatures

International Journal of Polymer Science ◽

10.1155/2018/1654295 ◽

2018 ◽

Vol 2018 ◽

pp. 1-12

Author(s):

Brent Tisserat ◽

Zengshe Liu ◽

Luke M. Haverhals

Keyword(s):

Mechanical Properties ◽

Cotton Wool ◽

Cold Temperatures ◽

Osage Orange ◽

Aqueous Solvent ◽

The Matrix ◽

Cellulose Breakdown ◽

Matrix Concentration ◽

Solvent Volume ◽

Agave Fibers

Lignocellulosic composites (LCs) were fabricated by partially dissolving cotton to create a matrix that was reinforced with osage orange wood (OOW) particles and/or blue agave fibers (AF). LCs were composed of 15–35% cotton matrix and 65–85% OWW/AF reinforcement. The matrix was produced by soaking cotton wool in a cold aqueous alkaline/urea solvent and was stirred for 15 minutes at 350 rpm to create a viscous gel. The gel was then reinforced with lignocellulosic components, mixed, and then pressed into a panel mold. LC panels were soaked in water to remove the aqueous solvent and then oven dried to obtain the final LC product. Several factors involved in the preparation of these LCs were examined including reaction temperatures (−5 to −15°C), matrix concentration (15–35% cotton), aqueous solvent volume (45–105 ml/panel), and the effectiveness of employing various aqueous solvent formulations. The mechanical properties of LCs were determined and reported. Conversion of the cotton into a suitable viscous gel was critical in order to obtain LCs that exhibited high mechanical properties. LCs with the highest mechanical properties were obtained when the cotton wools were subjected to a 4.6% LiOH/15% urea solvent at −12.5°C using an aqueous solvent volume of 60 ml/panel. Cotton wool subjected to excessive cold alkaline solvents volumes resulted in irreversible cellulose breakdown and a resultant LC that exhibited poor mechanical properties.

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Basic Aspects of X-Ray Absorption In Quantitative Diffraction Analysis of Powder Mixtures

Powder Diffraction ◽

10.1017/s0885715600016432 ◽

1989 ◽

Vol 4 (2) ◽

pp. 66-69 ◽

Cited By ~ 8

Author(s):

Leroy Alexander ◽

Harold P. Klug

Keyword(s):

Internal Standard ◽

Case Analysis ◽

Direct Analysis ◽

Powder Mixtures ◽

Powder Specimen ◽

X Ray ◽

The Matrix ◽

Matrix Concentration ◽

Mathematical Relationships ◽

X Ray Absorption

AbstractThe mathematical relationships are developed which are pertinent to the quantitative analysis of powder mixtures for the case of diffraction from the surface of a flat powder specimen. These formulas relate the diffracted intensity to the absorptive properties of the sample. Three important cases are treated: (1) Mixture of n components; absorbing powder of the unknown equal to that of the matrix; concentration proportional to intensity. Direct analysis is permitted. (2) Binary mixture; absorbing powder of the unknown not equal to that of the diluent; concentration not proportional to intensity. Direct analysis is possible by means of calibration curves prepared from synthetic mixtures. (3) Mixture of n components; absorbing power of the unknown not equal to that of the matrix; general case. Analysis is accomplished by the addition of an internal standard. Concentration is proportional to the ratio of the intensity of a selected reflection from the unknown to the intensity of a reflection from the internal standard.

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A practical approach to non-spectral interferences elimination in inductively coupled plasma optical emission spectrometry

Chemical Papers ◽

10.1515/chempap-2016-0004 ◽

2016 ◽

Vol 70 (6) ◽

Author(s):

Anna Krejčová ◽

Tomáš Černohorský ◽

Lenka Bendakovská

Keyword(s):

Inductively Coupled Plasma ◽

Matrix Effects ◽

Optical Emission ◽

Optical Emission Spectrometry ◽

Emission Spectrometry ◽

Spectral Interferences ◽

Inductively Coupled ◽

The Matrix ◽

Plasma Optical Emission Spectrometry ◽

Matrix Concentration

AbstractMatrix effects and practical possibilities of reducing accompanying non-spectral interferences in inductively coupled plasma optical emission spectrometry (ICP-OES) were studied for microconcentric Micromist, concentric and V-groove nebulizers (VGN) coupled with two cyclonic spray chambers of different sizes. The effect of a wide scale of interferents and mixtures thereof in the concentration range of up to 2 mass % (Na, Ca, Ba, La, urea) or up to 20 vol. % (nitric acid) on the analysis of Cd, Cu, K, Mg, Mn, Pb and Zn was investigated in terms of their analytical recovery and Mg(II) 280.27 nm/Mg(I) 285.29 nm line intensity ratio. Recoveries of ionic lines were lower than those of atomic lines (37–102 %) depending on the matrix concentration. The Mg(II)/Mg(I) ratios were found to be 12–15 and they slightly decreased as the matrix load increased. Exceptional behavior of pure La matrix, steeply lowering the recoveries and Mg(II)/Mg(I) ratios was observed. A Micromist nebulizer coupled with a small inner volume spray chamber provided the highest recoveries (94–102 %), lowest matrix effects across the matrix loads and, compared to others, the least significant dependence without worsening of the analytical characteristics (recoveries, signal background ratios and the Mg(II)/Mg(I) ratios) across the studied matrices.

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Preparation and Properties of Rigid Carbon Felt Thermal Insulation

Materials Science Forum ◽

10.4028/www.scientific.net/msf.833.48 ◽

2015 ◽

Vol 833 ◽

pp. 48-51 ◽

Cited By ~ 1

Author(s):

Wei Shi ◽

Jia Yan Li ◽

Qi Fan You ◽

Tong Lu ◽

Yi Tan

Keyword(s):

Mechanical Properties ◽

Thermal Conductivity ◽

Compressive Strength ◽

Thermal Insulation ◽

Bending Strength ◽

High Thermal Conductivity ◽

Carbon Felt ◽

Matrix Concentration ◽

Thermal Conductivities

Matrix derived from resin after carbonization in rigid carbon felt thermal insulation has many advantages. The microstructures and properties of these materials were investigated in this paper. Results showed that matrix tend to accumulate at the intersections of fibers. This can improve mechanical properties and have a little influence on thermal conductivities of the composites. The excellent bending strength of 2.66MPa, compressive strength of 0.91MPa and a high thermal conductivity of 0.81W/(m·K) (at 1500°C) with a matrix concentration of 32.7% is achieved. However, high thermal conductivity is harmful for those materials which are used as thermal insulators.

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