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Results 351 - 400 of 2853
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Ai Fang-Fang - - 2014
In order to discriminate premium quality from inexpensive edible oils, the fatty acid profiles of tea, rapeseed, corn, sunflower and sesame oil were compared with the ones from extra virgin olive oil (EVOO). Fatty acid methyl esters were quantified by GC/MS. Principal component analysis (PCA) and random forests (RF) were ...
Condino Anna Maria - - 2013
The purpose of this study was to investigate whether the documented difficulties of physiological amounts of essential amino acids (EAAs) (7 g) to induce protein synthesis could be reflected in a simple method adaptable to a clinical setting. Sixteen healthy individuals, nine elderly (75.3 ± 3.5 years), and seven young (28 ± 2.5 years) were ...
Hu Shun-Wei - - 2013
A fraction of humic acid is collected under acidic conditions, then immobilized on silica gel and used as the adsorbent for various symmetrical triazine (s-triazine) derivatives in hexane. The enhanced hydrogen bonding between the analyte and humic fraction molecules, not the complexation interaction, is responsible for the adsorption observed in ...
Zhang Lei - - 2013
A stepwise chemical reaction strategy based on the specific recognition of boronic acid to diol, and N-hydroxysuccinimide (NHS) ester to amine group, was designed to construct a "signal on" electrochemiluminescence (ECL) platform for highly sensitive detection of dopamine. A boronic acid-functionalized pyrene probe was synthesized and was self-assembled on the ...
Thomas Tony - - 2013
A biocompatible electrochemical sensor for selective detection of epinephrine (EP) in the presence of 1000-fold excess of ascorbic acid (AA) and uric acid (UA) was fabricated by modifying the carbon paste electrode (CPE) with multi-walled carbon nanotubes (MWCNTs) using a casting method. The electro-catalytic activity of the modified electrode for ...
Lee Doris - - 2013
The combination of a boronic acid and a Lewis base, both employed in substoichiometric amounts, enables the regioselective silylation of cis-diol groups in alkylpyranoside substrates. The proposed mode of activation involves the formation of a tetracoordinate adduct that displays enhanced nucleophilicity at the boron-bound alkoxide groups.
Wacker Ulrike - - 2013
The kinetic nature of the phosphoric acid digestion reaction enables clumped isotope analysis of carbonates using gas source isotope ratio mass spectrometry (IRMS). In most laboratories acid digestions are performed at 25°C in sealed vessels or at 90°C in a common acid bath. Here we show that different Δ47 results ...
Agcam E - - 2014
Processing of orange juice by pulsed electric fields (PEF) and thermal pasteurisation was carried out to compare changes in total phenolic concentration, hydroxybenzoic acid, hydroxycinnamic acids, flavonols, flavones and flavonones before and after being stored at 4°C for 180days. Changes in the initial total phenolic concentration of the samples varied ...
Alzweiri Muhammed - - 2013
Azelaic acid, a naturally occurring saturated dicarboxylic acid, is found in many topical formulations for its various medical benefits or as a byproduct of the oxidative decomposition of unsaturated fatty acids. The poor volatility of azelaic acid hinders its applicability in GC analysis. Therefore, azelaic acid was derivatized by methylation ...
Emrullahoğlu Mustafa - - 2013
A BODIPY-based fluorescent probe integrated with an aldoxime unit shows a remarkable fluorescence ''turn-on'' response to hypochlorous acid (HOCl). The oxidative dehydrogenation of BODIPY aldoxime by HOCl results in a distinct fluorescence enhancement as well as a change in color from red to orange.
Park Daechul - - 2013
A bacteria-based microrobot (bacteriobot) was proposed and investigated as a new type of active drug delivery system because of its useful advantages, such as active tumor targeting, bacteria-mediated tumor diagnosis and therapy. In this study, we fabricated a bacteriobot with enhanced motility by selective attachment of flagellar bacteria (Salmonella typhimurium). ...
Lee Jae-Ho - - 2013
Abstract The radiolabeling of the liposome surface can be a useful tool for in vivo tracking of therapeutic drug loaded liposomes. We investigated radiolabeling therapeutic drug (i.e. an antibiotic, amikacin) loaded liposomes with (99m)Tc, nebulization properties of (99m)Tc-labeled liposomal amikacin for inhalation ((99m)Tc-LAI), and its stability by size exclusion low-pressure ...
Bayram Ezgi - - 2013
In the biosensor construction, 3-mercaptopropionic acid (3-MPA) and 6-aminocaproic acid (6-ACA) were used for forming self-assembled monolayer (SAM) on a gold disc electrode and pyruvate oxidase was immobilized on the modified electrode surface by using glutaraldehyde. Biosensor response is linearly related to pyruvate concentration at 2.5-50 μM, detection limit is ...
Spier Eyal - - 2013
The homolytic scission of peroxides with catalytic amounts of cobalt(II) complexes is used in several industrial oxidation processes. In this contribution, we report that addition of small amounts of octanoic acid significantly enhances the catalytic deperoxidation activity of the cobalt(II)acetylacetonate complex. We attribute this to the stabilization of the CoOOR ...
Wang Zhen - - 2013
The aim of this study was to evaluate the use of hydrolysates from acid hydrolysis of four different oil crop biomass residues (OCBR) as low cost culture media for algae growth. The one-factor-at-a-time method was used to design a series of experiments to optimize the acid hydrolysis conditions through examining ...
Karaman Rafik - - 2013
Based on density functional theory (DFT) calculations for the acid-catalyzed hydrolysis of several maleamic acid amide derivatives four tranexamic acid prodrugs were designed. The DFT results on the acid catalyzed hydrolysis revealed that the reaction rate-limiting step is determined on the nature of the amine leaving group. When the amine ...
Feketeová Linda - - 2013
Oxidative damage to DNA yields guanine radical cations. Their gas-phase IR spectroscopic signature and acidity have been modelled by the radical cation of 9-methylguanine. Comparisons with quantum chemistry calculations suggest that radical cation formation produces the ground-state keto tautomer, which has an N-H acidity enhanced by ∼470 kJ mol(-1).
Liu Wei - - 2013
The purpose of this work was to recover isoflavone aglycones from industrial soy whey wastewater, where the isoflavone aglycones mainly existed in the form of β-glycosides. First, foam fractionation was used for effectively concentrating the total soy isoflavones, including isoflavone aglycones and β-glycosides, from the wastewater. Fourier transform infrared spectroscopy ...
Singhvi Mamata - - 2013
The production of d-lactic acid by Lactobacillus lactis RM2-24 was investigated using modified media to increase the efficiency of the fermentation process. The results indicated that the addition of 5g/l peptone and 1g/l (NH4)2HPO4 enhanced d-lactic acid production by 32%, as compared to that obtained from non supplemented media, with ...
Sheng Hua - - 2013
Relay race: By using polyprotic-acid-based pendant proton relays (phosphate, L-glutamic acid, and malonic acid), the oxygen reduction reaction (ORR) on a TiO2 surface is switched from a single-electron process to a concerted 4 e(-) /4 H(+) reduction to H2 O. In contrast, monocarboxylic acids (PA and AA) without pendant proton relays only ...
Liu Jinwei - - 2013
Elicitation is an important strategy to improve production of secondary metabolites in vitro. Artemisinic acid was studied as a novel elicitor to enhance the yield of terpenoid indole alkaloids in the present paper. Our results demonstrated that the concentrations of vindoline and vinblastine were increased by sixfold and twofold, respectively, ...
Zhang Baixi - - 2013
Conjugated linoleic acid (CLA) has been extensively studied for decades because of its health benefits including cancer prevention, anti-atherogenic and anti-obesity effects, and modulation of the immune system. We previously described the production of trans-10, cis-12 CLA in Yarrowia lipolytica by expressing the gene coding for linoleic acid isomerase from ...
Serveau-Avesque Carole - - 2013
We have designed a convenient, specific, sensitive and continuous lipase assay based on the use of natural triacylglycerols (TAGs) from the Aleurites fordii seed oil which contains α-eleostearic acid (9,11,13,cis,trans,trans-octadecatrienoic acid) and which was coated in the wells of microtiter plates. The coated TAG film cannot be desorbed by the ...
Lee Han Ju - - 2013
A new carboxylic acid-terminated alkanethiol having bidentate character, 16-(3,5-bis(mercaptomethyl)phenoxy)hexadecanoic acid (BMPHA), was designed as an absorbate and protectant to form thermally stable carboxylic acid-terminated organic thin films on flat gold and nanoparticles, respectively. The structural features of the organic thin films derived from BMPHA were characterized by ellipsometry, X-ray photoelectron ...
Kim Jong-Yea - - 2013
Potato starch was subjected to heat-moisture treatment (HMT; 120°C, 3h) under mildly acidic conditions (pH 5, 6, or 6.5 [control]) at moisture levels of 15, 20 or 25%. HMT starches exhibited significantly delayed pasting times and reduced overall paste viscosities, amylose leaching, and granular swelling characteristics relative to native starch, ...
Wang Xin - - 2013
Activated carbon (AC) is a high performing and cost effective catalyst for oxygen reduction reactions (ORRs) of air-cathodes in microbial fuel cells (MFCs). Acidic (HNO3) and alkaline (KOH) pretreatments on AC at low temperature (85°C) are conducted to enhance the performance of MFCs. The alkaline pretreatment increased the power density ...
Suneesh P V - - 2013
Tantalum oxide honeycomb nanostructures (THNS) were fabricated by electrochemical anodisation of tantalum in H2SO4-HF medium. XRD analysis showed that annealing of THNS at 400°C improves the crystallinity. HRSEM and AFM results illustrated that nanopores with an average diameter of 30nm were uniformly distributed and the pore size reduced to 24nm ...
Goriparti Subrahmanyam - - 2013
Ellagic acid, a naturally occurring polyphenol, extracted from pomegranate husk, is found to be a very good organic electrode material for rechargeable lithium batteries with high reversible capacities of ∼450 and 200 mA h g(-1) at C/10 and C/2.5 discharge rates, respectively; ex situ NMR studies reveal possible lithiation-delithiation modes ...
Liu Rui-Lin - - 2013
Based on microwave-ultrasonic synergistic in situ extraction-derivatisation (MUED), gas chromatography-mass spectrometry was proposed for rapid analysis of fatty acid profiles in raw nut and seed materials. Several critical experimental parameters for MUED, including reaction temperature, microwave power, amounts of catalyst and derivatisation reagent, have been optimised using response surface methodology. ...
Wang Wen - - 2013
Acid and alkaline pretreatments for enhanced hydrogen production from cassava stillage were investigated in the present study. The result showed that acid pretreatment was suitable for enhancement of soluble carbohydrate while alkaline pretreatment stimulated more soluble total organic carbon production from cassava stillage. Acid pretreatment thereby has higher capacity to ...
Tsubaki Shuntaro - - 2013
Polyoxometalate (POM) clusters were utilized as recyclable acid catalysts and microwave-absorbing agents for the microwave-assisted hydrolysis of corn starch and crystalline cellulose. Phosphotungstic (PW) and silicotungstic (SiW) acids showed high hydrolyzing activity, while phosphomolybdic acid (PMo) showed lower glucose stability. The PW catalyst could be recycled by ether extraction at ...
Deo Kirti S - - 2013
Melasma is a relatively common, acquired symmetric hypermelanosis characterized by irregular light to gray-brown macules involving sun-exposed areas. Kojic acid, with its depigmenting potential due to tyrosinase inhibition and suppression of melanogenesis, has become a vital component of the dermatologists' armamentarium against melasma. To study and compare the efficacy of ...
Desriac N - - 2013
This study aims to quantify the effect of salt and acid preliminary exposure on acid resistance of vegetative cells of Bacillus weihenstephanensis. The psychrotolerant strain KBAB4 was cultured until the mid-exponentially phase (i) in BHI, (ii) in BHI supplemented with 2.5% salt or (iii) in BHI acidified at pH 5.5 ...
Sinha Sukumar - - 2013
A simple, sensitive method for the determination of meta-chlorobenzoic acid in bupropion hydrochloride is described. Chromatographic separation of m-chlorobenzoic acid is achieved using a mobile phase consisting of n-hexane and ethanol (1000:50, v/v) at a flow rate of 1.0 ml/min on a Chiralpak ADH (250 × 4.6 mm). Absorbance is ...
Miftodei Alina Monica AM Discipline of Inorganic Chemistry, University of Medicine and Pharmacy "Grigore T. Popa" - - 2013
Through univalent oxidation chlorpromazine forms a colored and relatively stable radical cation with maximum absorbance at 525 nm, considered a redox mediator in a number of b iochemical reactions. To develop a spectrometric method for the determination of total antioxidant activity based on the reaction of chlorpromazine radical capture by ...
Ali M Abbas MA Department of Chemistry, Rajshahi University of Engineering and Technology, - - 2013
Background. Microwave heating is one of the most attractive cooking methods for food preparation, com-monly employed in households and especially in restaurants for its high speed and convenience. The chemical constituents of oils that degrade during microwave heating do so at rates that vary with heating temperature and time in ...
Abid Muhammad - - 2013
A study was initiated with the objective of evaluating the effects of sonication treatment on quality characteristics of apple juice such as polyphenolic compounds (chlorogenic acid, caffeic acid, catechin, epicatechin and phloridzin), sugars (fructose, glucose and sucrose), mineral elements (Na, K, Ca, P, Mg, Cu and Zn), total carotenoids, total ...
Wang Qi - - 2013
A sensitive electrochemical active interface for sugar sensing based on the specific boronic acid-diol binding was established. The sensing matrix was formed by stirring a suspension of graphene oxide (GO) with 4-aminophenylboronic acid (APBA). The resulting composite consists of a water insoluble precipitate of reduced graphene oxide (rGO) with APBA ...
Chen Suming - - 2013
Carbon nanodots were applied for the first time as a new matrix for the analysis of low-molecular-weight compounds by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) in both positive- and negative-ion modes. A wide range of small molecules including amino acids, peptides, fatty acids, as well as β-agonists and ...
Giuberti G - - 2013
The need to improve the knowledge of fermentation processes within the digestive tract in pigs is growing, particularly for ingredients that may act as potential prebiotic sources, such as resistant starch (RS). A study (based on enzymatic digestion followed by in vitro fermentation) was conducted to investigate whether various sources ...
Park Soo-Yun - - 2013
In the present study, carotenoids, anthocyanin and phenolic acids of cauliflowers (Brassica oleracea L. ssp. botrytis) with various colored florets (white, yellow, green and purple) were characterized to determine their phytochemical diversity. Additionally, 48 metabolites comprising amino acids, organic acids, sugars and sugar alcohols were identified using gas chromatography-time-of-flight mass ...
Freitas Maria Betânia de - - 2013
The nitroaromatic compound 4-bromomethyl-3-nitrobenzoic acid (ANB) is a promising antitumoral agent whose activity has recently been investigated. Forced degradation studies were conducted on ANB with a high-performance liquid chromatography-ultraviolet assay to establish its stability and selectivity. ANB was subjected to degradation studies under hydrolytic (acid and alkaline), oxidative and light ...
Madeira Pedro P - - 2013
Partition ratios of 8 free l-amino acids (Gln, Glu, His, Lys, Met, Ser, Thr, and Tyr) were measured in 10 different polymer/polymer aqueous two-phase systems containing 0.15 M NaCl in 0.01 M phosphate buffer, pH 7.4. The solute-specific coefficients representing the solute dipole/dipole, hydrogen-bonding and electrostatic interactions with the aqueous environment of ...
Liang Liya - - 2013
In this study, repetitive production of succinic acid from lignocellulose hydrolysates by enhancement of ATP supply in metabolically engineered E. coli is reported. Escherichia coli BA305, a pflB, ldhA, ppc, and ptsG deletion strain overexpressing ATP-forming phosphoenolpyruvate (PEP) carboxykinase (PEPCK), produced a final succinic acid concentration of 83gL(-1) with a ...
Braunberger Christina - - 2013
The herb of Drosera peltata, commonly named the shield sundew, is used as an antitussive in phytotherapy, although the plants' composition has not been determined in detail so far. Hence, in this study, we present a validated, sensitive, reliable, and cheap narrow-bore LC-DAD method for the simultaneous quantification of flavonoids ...
Kim Hyun-Wook - - 2013
This study was conducted to evaluate the antioxidant effects of soy sauce on lipid oxidation and color stability of raw beef patties. Raw beef patties were formulated with four solutions such as NaCl (sodium chloride solution), NaCl/SS (1:1 ratio of sodium chloride and soy sauce solution), SS (soy sauce solution), ...
Malaj Naim - - 2013
Anthocyanins are a natural source of pigments in plants and their processed food products have become attractive and excellent candidates to replace the synthetic colourants due to their characteristic intense colours and associated health benefits. The intermolecular copigmentation between anthocyanins and other colourless compounds has been reported to be an ...
Piergies Natalia - - 2013
This paper shows systematic spectroscopic studies using Fourier-transform infrared absorption (FT-IR), Fourier-transform Raman (FT-Raman), and surface enhanced Raman (SERS) in an aqueous silver sol of fluoro- and formyl- analogues of phenylboronic acids: 2-fluorophenylboronic acid (2-F-PhB(OH)2), 3-fluorophenylboronic acid (3-F-PhB(OH)2), 4-fluorophenylboronic acid (4-F-PhB(OH)2), 2-formylphenylboronic acid (2-CHO-PhB(OH)2), 3-formylphenylboronic acid (3-CHO-PhB(OH)2), and 4-formylphenylboronic acid ...
Hu Xianmei - - 2013
The potential use of arachidonic acid (AA) to enhance the production of β-carotene in Blakeslea trispora was investigated in this work. To study the mechanism of the B. trispora response to AA, we used a systematic analytical approach to investigate the changes in the B. trispora cell metabolome at different ...
Aadil Rana Muhammad - - 2013
Sonication is recognised as a potential technique for improvement in the quality of fruit juices. This study was initiated with the objective of evaluating the effect of sonication treatments on some important quality parameters of grapefruit juice such as physico-chemical (pH, acidity and °Brix), Hunter colour values (L(∗), a(∗) and ...
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