Whole blood and/or plasma amino acids are useful for monitoring whole body protein and amino acid metabolism in an organism under various physiological and pathophysiological conditions. Various methodological procedures are in use for their measurement in biological fluids. From the time when capillary electrophoresis was introduced as a technology offering ...

This paper describes the most important articles that have been published on amino acid analysis using CE during the period from June 2009 to May 2011 and follows the format of the previous articles of Smith (Electrophoresis 1999, 20, 3078-3083), Prata et al. (Electrophoresis 2001, 22, 4129-4138) and Poinsot et ...

Amino acid analysis is among the most accurate methods for absolute quantification of proteins and peptides. Here, we combine acid hydrolysis with the addition of isotopically labeled standard amino acids and analysis by mass spectrometry for accurate and sensitive protein quantitation. Quantitation of less than 10 fmol of protein standards ...

Red blood cell (RBC) n-3 fatty acid status is related to various health outcomes. Accepted biological markers for the fatty acid status determination are RBC phospholipids, phosphatidylcholine, and phosphatidyletholamine. The analysis of these lipid fractions is demanding and time consuming and total phospholipid n-3 fatty acid levels might be affected ...

INTRODUCTION: Triterpenic acids, such as maslinic acid and oleanolic acid, are commonly found in olive fruits and have been associated with many health benefits. The drying and extraction methods, as well as the solvents used, are critical factors in the determination of their concentration in plant tissues. Thus, there is ...

Phospholipid fatty acid (PLFA) as biomarkers, is widely used to profile microbial communities in environmental samples. However, PLFA extraction and derivatization protocols are not standardized and have widely varied among published studies. Specifically investigators have used either HCl/MeOH or KOH/MeOH or both for the methylation step of PLFA analysis, without ...

Single amino acid polymorphisms (SAPs), also known as non-synonymous single nucleotide polymorphisms (nsSNPs), are responsible for most of human genetic diseases. Discriminate the deleterious SAPs from neutral ones can help identify the disease genes and understand the mechanism of diseases. In this work, a method of deleterious SAP prediction at ...

This paper reports the use of plasma enhanced chemical vapor deposition (PECVD) for the simultaneous deposition and co-polymerization of an amino acid with other organic and inorganic monomers. We investigate the fundamental effects of plasma-enhanced co-polymerization on different material chemistries in stable ultrathin coatings with mixed composition with aminoacid component. ...

Trifluoroethylation: Aryl boronic acids can be catalytically trifluoroethylated with the readily available reagent CF(3) CH(2) I (see scheme, dba=dibenzylideneacetone). The reaction tolerates a variety of functional groups and can be extended to the trifluoroethylation of aryl or alkenyl boronic esters. The method is also suitable for the late-stage installation of ...

A time-resolved in situ micro-spectroscopic approach has been used to investigate the Brønsted acidic properties of fluid-catalytic-cracking (FCC) catalysts at the single particle level by applying the acid-catalysed styrene oligomerisation probe reaction. The reactivity of individual FCC components (zeolite, clay, alumina and silica) was monitored by UV/Vis micro-spectroscopy and showed ...

Most microorganisms remain uncultivated, and typically their ecological roles must be inferred from diversity and genomic studies. To directly measure functional roles of uncultivated microbes, we developed Chip-stable isotope probing (SIP), a high-sensitivity, high-throughput SIP method performed on a phylogenetic microarray (chip). This approach consists of microbial community incubations with ...

In alkaline pulping wood pulp is reacted with concentrated aqueous alkali at elevated temperatures. In addition to producing cellulose for the manufacture of paper, alkaline pulping also generates large amounts of isosaccharinic acids as waste products. Isosaccharinic acids are potentially useful raw materials: they are good metal chelating agents and, ...

Amino acid analysis (AAA) method is the most accurate methodology for absolute quantification of proteins. The conventional postcolumn method employing ninhydrin labeling of amino acids, which is adopted in automatic amino acid analyzer, is limited by low sensitivity. Therefore, a highly sensitive AAA method is required to confirm the data ...

This report intends to provide an updated overview of the most important methodological developments of MEKC in the field of qualitative/quantitative analysis of free amino acids in different matrices. A good number of articles published in the years 2009-2010 addresses the main applications of such procedures together with their advantages ...

The fundamental properties of the parent and substituted 2-pyridones (2-pyridone, 3-chloro-2-pyridone, 3-formyl-2-pyridone) have been examined in the gas phase using computational and experimental mass spectrometry methods. Newly measured acidities and proton affinities are reported and used to ascertain tautomer preference. These particular substrates (as well as additional 3-substituted pyridones) were ...

We describe herein a novel exonuclease III aided amplification method based on single walled carbon nanotube quenching (EASQ) for sensitive and convenient nucleic acid detection, which enabled 80-fold decrease of detection limit for HIV1 DNA assay compared with no target recycling.

A rapid synchronous spectrofluorimetric method was first developed for the simultaneous determination of folic acid and riboflavin in nutrimental beverages. Folic acid could be detected by using H(2)O(2) plus Cu(II) as oxidation system to produce pterine-6-carboxylic acid, which had strong fluorescence in aqueous solution, and riboflavin itself was obviously fluorescent. ...

The breakthrough discovery of the acid-etch procedure by Buonocore in the mid-1950s laid the groundwork for the development of pit and fissure sealant as the best preventive agent for use against the development and progression of pit and fissure caries. The acid-etch technique is also the foundational technology behind the ...

Ethylene glycol poisoning is a medical emergency that presents challenges both for clinicians and clinical laboratories. Untreated, it may cause morbidly or death, but effective therapy is available, if administered timely. However, the diagnosis of ethylene glycol poisoning is not always straightforward. Thus, measurement of serum ethylene glycol, and ideally ...

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) ...

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, ...

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 ...

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 ...

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 ...

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, ...

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 ...

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 ...

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.

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 ...

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 ...

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 ...

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 ...

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. ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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, ...

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).

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 ...

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.

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, ...

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.

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 ...

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 ...