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García-Delgado C - - 2012
Six digestion procedures were tested to improve extraction methods for determination of trace elements in various organic amendments with high inorganic fractions. These procedures were tested in terms of pH, CaCO(3), organic matter, elemental analysis, BCR sequential extraction and X-ray diffraction analysis. Aqua regia extraction (ISO 11466), total digestion HF-HNO(3)-HClO(4) ...
Bartus Cynthia L - - 2011
A number of injection techniques have been described for the placement of hyaluronic acid fillers. Such techniques include, but are not limited to, linear threading, depot, fanning, and layering. The tower technique for hyaluronic acid filler injection is a novel variation of the depot and layering techniques. With this technique, ...
Demange Martine - - 2011
In France, the MétroPol 009 method used to measure workplace exposure to inorganic acids, such as HF, HCl, and HNO(3), consists of a closed-face cassette fitted with a prefilter to collect particles, and two sodium carbonate-impregnated filters to collect acid vapor. This method was compared with other European methods during ...
Kim E J - - 2011
The objective of this study was to evaluate and compare amino acid digestibility of several feedstuffs using 2 commonly accepted methods: the precision-fed cecectomized rooster assay (PFR) and the standardized ileal amino acid assay (SIAAD). Six corn, 6 corn distillers dried grains with or without solubles (DDGS/DDG), one wet distillers ...
Robert-Peillard F - - 2012
This paper presents a simple, accurate and multi-sample method for the determination of volatile fatty acids (VFAs) thanks to a 96-well microplate technique. A procedure using an activating reagent of the carboxylic function (water-soluble carbodiimide EDC) and a fluorescent amino labeling reagent (N-(1-naphthyl)ethylenediamine, EDAN) allows the formation of an isoindole ...
Zhou L J - - 2011
The aim of this study was to develop near-infrared reflectance spectroscopy (NIRS) calibrations for determination of the fatty acids (FA) in broiler breast meat. A total of 144 breast meat samples were freeze-dried and divided into calibration set and validation set. Calibration models were developed for FA including C14:0, C16:0, ...
West N X - - 2011
OBJECTIVES: To determine if brushing dentine with 2 moderate RDA desensitising toothpastes, results in a significant dentine wear difference and whether this difference continues to be relevant when preceded with an erosive challenge. METHODS: An in situ, single centre, single blind, randomised, split mouth study, evaluated the difference in abrasion ...
Ji Linlin - - 2011
The antioxidant capacity of different fractions of 17 vegetables were analyzed using ferric reducing antioxidant power assay (FRAP assay) after water and acetone extractions. The contents of ascorbic acid, phenolics, and flavonoids were determined and their correlations with FRAP value were investigated. The results showed that the peel or leaf ...
Zheng Xiaoxi - - 2011
Magnetic polyoxometalates (POMs) are obtained by a simple sonication between functionalized magnetic nanoparticles and polyoxometalates. This material can be used not only as a highly active acid catalyst, but also as a catalyst support for chiral amines.
Ozogul Yesim - - 2011
This study aims to evaluate the efficiency of trans-methylation methods in fish oil obtained using Soxhlet extraction method and Bligh and Dyer method and also to observe the effects of extraction methods on the contents of polyunsaturated fatty acids [PUFAs, especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)] in five ...
Sauvinet Valérie - - 2011
During nutritional interventions, the ingestion of d(31) -palmitic acid and H(2) (18) O allows the assessment of dietary fatty acid oxidation from cumulative (2) H recovery in urine and the estimation of the total body water pool (TBW) from (18) O dilution. Continuous-flow isotope ratio mass spectrometry (CF-IRMS) coupled to ...
Ruan Ming - - 2011
Guan-Xin-Ning (GXN) injection, a traditional Chinese medicinal preparation consisting of Radix Salvia miltiorrhiza and Rhizoma Ligusticum chuanxiong, has been used to treat coronary heart disease and angina pectoris in China for decades. In this paper, a HPLC/DAD/ESI-MS(n) method was successfully developed for qualitative and quantitative analysis of the active components ...
Saha Indrajit - - 2012
In this article, we categorize presently available experimental and theoretical knowledge of various physicochemical and biochemical features of amino acids, as collected in the AAindex database of known 544 amino acid (AA) indices. Previously reported 402 indices were categorized into six groups using hierarchical clustering technique and 142 were left ...
Stoikov Ivan - - 2011
In this work, the formation of two- and three-component supramolecular systems based on cone, partial cone, 1,3-alternate stereoisomers of heteroditopic "hosts" - p-tert-butylthiacalix[4]arene containing 4-amidopyridine fragments with silver (I) cations and dicarboxylic acids in liquid and solid phases were studied by UV spectroscopy, dynamic light scattering and atomic-force microscopy methods. ...
Xiao Feng - - 2011
A sensitive liquid chromatographic-mass spectrometric technique coupled with liquid-liquid extraction method was developed and validated for simultaneous determination of dehydro-tumulosic acid, tumulosic acid and polyporic acid C in rat plasma. The analytes were separated on a Kromasil C(18) column with a total running time of 12.5min. Author had compared the ...
Jochym Kamila - - 2011
BACKGROUND: New starch preparations were produced by thermolysis of potato starch in the presence of inorganic (hydrochloric) and organic (citric and tartaric) acids under controlled conditions. The starch preparations were physicochemically and structurally characterised and analysed for their resistance to enzymatic digestion in vitro. RESULTS: The content of resistant fraction ...
Notghi Alp - - 2011
TauroH-23-((75)Se)selena-25-homocholic acid (SeHCAT) retention has been used for the diagnosis of bile acid malabsorption since the early 1980s. Bile acid malabsorption has been increasingly recognized as an important cause of severe chronic diarroea with subsequent increase in the number of referrals for the SeHCAT test. In this study, we review ...
Shen Su Fen - - 2011
Under certain acidic condition, thioglycolic-acid-modified gold nanoparticles (Au-NPs) can react with melamine, resulting in the aggregation of Au-NPs through electrostatic interactions between -COO(-) groups on the surface of Au-NPs and -NH3+ groups of melamine. The aggregation extent depends on the concentration of melamine, which can be validated by SEM imaging ...
Samanta Debasis - - 2011
A simple and convenient method to prepare acid-responsive microcapsules by using functionalized single-walled carbon nanotubes and ytterbium triflate has been developed. Fluorescence active compounds were "pre-loaded" or "post-loaded" in the microcapsules and released later in acidic medium. An interesting "zip-unzip" phenomenon was observed while filming the action of acid on ...
Trader Darci J DJ Department of Chemistry, Indiana University, 212 South Hawthorne Drive, Bloomington, Indiana 47405, - - 2011
Although the carboxylic acid moiety is prevalent in many biologically produced molecules, including natural products and proteins, methods to chemoselectively target this functional group have remained elusive. Generally, strategies that utilize carboxylate nucleophilicity also promote reactions with other nucleophiles such as amines and hydroxyls. A reagent was sought to facilitate ...
Batran Sa-E - - 2011
Abstract Acid mucins have diagnostic significance for many pathological conditions, especially in certain tumors. We compared the classical pH 2.5 Alcian blue method to a new, improved zirconyl hematoxylin (IZH) method for demonstrating acid mucins using two fixatives: Bouin`s solution and 10% neutral buffered formalin (NBF). We used rabbit small ...
Takenaka Yuko - - 2011
Glycolic acid chemical peeling is effective for treating comedones, and some clinical data show that it also improves inflammatory eruptions. The purpose of this study was to identify the mechanism of glycolic acid chemical peeling to improve inflammatory acne. To assess growth inhibitory and bactericidal effects of glycolic acid on ...
Leonard Nicholas M - - 2011
A method for the in situ formation of N-trifluoroacetoxy succinimide (TFA-NHS) and its application in the formation of succinimidyl esters is presented. The developed method provides N-trifluoroacetyl and N-maleoyl amino acid succinimidyl esters from a variety of amino acids using a one-pot, high yielding protocol. Investigations into the formation of ...
Guan Wenna - - 2011
Simple and rapid quantitative determination of fatty-acid-based biofuels is greatly important for the study of genetic engineering progress for biofuels production by microalgae. Ideal biofuels produced from biological systems should be chemically similar to petroleum, like fatty-acid-based molecules including free fatty acids, fatty acid methyl esters, fatty acid ethyl esters, ...
Zhao Yingjie - - 2011
A rotaxane incorporating three different stations and fluorescent states (output) was prepared. The movement of the macrocycle can be easily detected by fluorescence change as an output signal and the macrocycle could be easily controlled to locate on three different stations of the thread by the tuning of acid/base (input).
Nazemi M K - - 2011
Effective recovery of nickel (Ni) from spent NiO/Al(2)O(3) catalyst in a simple hydrometallurgical route is suggested. Nickel recovery of 99.5% was achieved with sulfuric acid leaching. The leach liquor was partly neutralized and nickel ammonium sulfate was precipitated by adding ammonia. The nickel in the supernatant was concentrated by solvent ...
Kitanovski Zoran - - 2011
In this comment we want to draw attention to some weaknesses of the analytical method used for quantification of the organosulfates, which are influencing the end results, and thus the conclusions. We also try to suggest some possible improvements on the basis of our experience and knowledge.
Andrási N - - 2011
An exhaustive GC-MS acquisition study was performed, for the simultaneous analysis of natural and synthetic steroids and cholic acids (in order to insert them into the last tierce of our multiresidue analysis system), such as androsterone, β-estradiol, transdehydroandro-sterone, transdehyroandrosterone, mestranol, dihydrotestosterone, ethinylestradiol, testosterone, norethisterone, estriol, 4-androstene-3,17-dione, gestodene, levonorgestrel, etonogestrel, coprostanol, ...
McCubbin J Adam - - 2011
An efficient and simple catalytic method for the isomerization of readily prepared allylic alcohols is described. We focus particularly on cyclic examples and the synthesis of unusual enyne and dienols. The benzoic acid catalysts employed are commercially available, very inexpensive and can be tuned for reactivity and substrate sensitivity.
Xu Yanping Y New Use Agriculture and Natural Plant Products Program, Department of Plant Biology and Pathology, Rutgers University , 59 Dudley Road, New Brunswick, New Jersey 08901, United - - 2011
A rapid and comprehensive qualitative method has been developed to characterize the different classes of polyphenols, such as anthocyanins, flavonols, phenolic acids, and flavanols/proanthocyanidins, in grape products. The detection was achieved by two runs with the same LC gradient in different MS ionization modes and mobile phase modifiers (positive ionization ...
Huang Gangliang - - 2011
The alkali-insoluble (1 → 3)-β-d-glucan was prepared by alkaline-acid method and followed deproteinization by alkaline method using yeast cell wall as the starting material. The deproteinized product was characterized by infrared (IR) spectroscopy, and the polysaccharide components were analysed by paper chromatography. It indicated that the alkaline-acid method was an ideal way ...
Michałowski Tadeusz - - 2011
The isohydricity (pH constancy) principle is referred to the pair of solutions: weak acid (HL, C(0)mol/L) and strong acid (HB, Cmol/L) when mixed e.g., according to titrimetric mode. Such a case takes place if the relation C(0)=C+C(2)×10(pK(1)) is valid, where pK(1)=-logK(1), K(1) - dissociation constant for a weak monoprotic acid ...
Trincado Mónica - - 2011
Several polyols, which are easily available from sugars through biochemical conversion or hydrogenolytic cleavage, are directly converted into carboxylic acids and amides. This efficient dehydrogenative coupling process, catalyzed by a rhodium(I) diolefin amido complex, is an attractive approach for the production of organic fine chemicals from renewable resources. This method ...
Tan Fuyuan - - 2011
In this paper, a novel application of alternating penalty trilinear decomposition (APTLD) for high performance liquid chromatography with fluorescence detector (HPLC-FLD) has been developed to simultaneously determine the contents of free amino acids in tea. Although the spectra of amino acid derivatives were similar and a large number of water-soluble ...
Kurpad Anura V - - 2011
There are now different stable isotopic methods to measure minimum daily human indispensable amino acid (IAA) requirements. There has been debate on the appropriateness of statistical methods used to define the nature of change in the response. Current isotopic methods measure daily amino acid oxidation and balance of the IAA ...
Kim Jong Min - - 2011
This study demonstrates a new approach for the highly selective molecular recognition of chiral mandelic acid using an L-mandelic acid derivative with an optically active hydroxyl group as the selector. The proposed method is based on quartz crystal microbalance (QCM) detection combined with functional multilayer film techniques in a liquid ...
Bigelow Nicholas W - - 2011
Fatty acid analysis is essential to a broad range of applications including those associated with the nascent algal biofuel and algal bioproduct industries. Current fatty acid profiling methods require lengthy, sequential extraction and transesterification steps necessitating significant quantities of analyte. We report the development of a rapid, microscale, single-step, in ...
Bloom Steven - - 2011
The selective α,α-difluorination of carbonyl compounds remains a challenge in modern organic synthesis; current methods often incorporate stepwise processes and/or harsh conditions, providing unsatisfactory mixtures of mono- and difluorinated products. In this communication, a practical, mild, and one-pot method for the selective α,α-difluorination of readily available acid chlorides is reported ...
Komoriya Tomoe - - 2011
Various convenient and high-sensitivity immunoassays based on luminescent oxygen channeling and chromatographic techniques have been developed in recent years. This study focused on the latex agglutination immunoassay because it is a simple, homogenous immunoassay, which is also cost effective. We developed a highly sensitive latex reagent and examined the method ...
Baptista Mafalda S - - 2011
A capillary electrophoretic method for the determination of the amino acid β-N-methylamino-l-alanine (BMAA) was achieved using a fused-silica capillary column (50 cm × 75 μm I.D.) filled with 5 mM sodium tetraborate solution (pH 9), with an applied voltage of 25 kV, at 25 °C. The method was then applied in quantifying BMAA in eighteen strains of ...
Yang Xing - - 2011
A new method for catalytic nonenzymatic kinetic resolution of α-substituted alkanoic acids has been developed, which relies on their activation with DCC followed by enantioselective alcoholysis of the intermediate symm-anhydrides in the presence of the amidine-based catalyst homobenzotetramisole (HBTM). Moderate to excellent selectivity factors (s=5-96) have been obtained in the ...
Zhu Shujie - - 2011
C-Acylimines 1 undergo intermolecular amidation with amides 2 to produce monoacyl gem-diamino acid derivatives 3 upon treatment with Cu(OTf)(2) (20 mol %)/ PPh(3) (20 mol %) under mild conditions. This method provides an efficient access to gem-diamino acid equivalents with good to excellent yields.
Williams Caroline M - - 2011
Triacylglycerides (TAGs) are the most important stored energy reserve in eukaryotes and are regularly measured in insects. Quantitative analysis of TAGs is complicated by their diversity of structure, and there are concerns with the quantitative accuracy of commonly used analytical methods. We used thin layer chromatography coupled to a flame ...
Genady Afaf R - - 2011
An efficient method for synthesis of cyclohexyl and cyclohexenyl α-amino acids via palladium-catalyzed three-component assemblies followed by ring-closing metathesis (RCM) is described. The present catalytic reaction is successfully extended to substituted benzylidene azlactones 2a-j RCH=(1,3-oxazole): R = alkyl or aryl. The amphiphilic bis-allylation of these substrates has been achieved by ...
Tai Akihiro - - 2011
6-O-Dodecanoyl-2-O-α-d-glucopyranosyl-l-ascorbic acid (6-sDode-AA-2G) was synthesized from 2-O-α-d-glucopyranosyl-l-ascorbic acid and lauric anhydride with a polymer catalyst, poly(4-vinylpyridine), in N,N-dimethylformamide without the introduction of protecting groups. The optimum reaction conditions enabled 6-sDode-AA-2G to be synthesized in a yield of 49.7%. The yield and the regioselectivity in this method were far superior to ...
Vijaya Bharathi D - - 2011
A highly sensitive, selective and evaporation free SPE extraction, ESI-LC-MS/MS method has been developed for estimation of misoprostol free acid in human plasma using misoprostol acid-d(5) as an internal standard (IS). The analyte was separated using isocratic mobile phase on reverse phase column and analyzed by MS/MS in the multiple ...
Lipping Lauri - - 2011
The gas-phase acidities of ca 60 monosubstituted anilines (with acidity span of almost 50 kcal mol-1) have been calculated using density functional theory (DFT) at B3LYP/6-311+G** level. At this relatively simple level of theory the calculated (DGcalc) and available experimental (DGexp) acidities are in a reasonable quantitative correlation according to ...
Bumbu Valentina D - - 2011
The first catalytic, nonenzymatic kinetic resolution of β-lactams has been achieved. Alcoholysis of their N-aroyl derivatives in the presence of a simple chiral acyl transfer catalyst, benzotetramisole, produces β-amino acid derivatives with excellent enantioselectivity.
Visser Wouter F - - 2011
d-Amino acids are increasingly being recognized as important signaling molecules in mammals, including humans. d-Serine and d-aspartate are believed to act as signaling molecules in the central nervous system. Interestingly, several other d-amino acids also occur in human plasma, but very little is currently known regarding their function and origin. ...
Hathwar Venkatesha R - - 2011
An extension of the supramolecular synthon-based fragment approach (SBFA) method for transferability of multipole charge density parameters to include weak supramolecular synthons is proposed. In particular, the SBFA method is applied to C-H···O, C-H···F, and F···F containing synthons. A high resolution charge density study has been performed on 4-fluorobenzoic acid ...
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