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Results 201 - 250 of 1679
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Buurmans Inge L C - - 2011
Fluid catalytic cracking (FCC) is the major conversion process used in oil refineries to produce valuable hydrocarbons from crude oil fractions. Because the demand for oil-based products is ever increasing, research has been ongoing to improve the performance of FCC catalyst particles, which are complex mixtures of zeolite and binder ...
Pradeep S R SR Department of Grain Science and Technology, Central Food Technological Research Institute, Mysore 570020, - - 2011
The effect of germination, steaming and roasting on the nutraceutical and antioxidant properties of little millet (Panicum sumatrense) was investigated. The nutraceutical properties were determined by evaluating the total phenolic, flavonoid and tannin contents while the antioxidant properties were studied by the DPPH free radical scavenging activity and the iron ...
Yuan Hongjuan - - 2010
Hydrobromic acid was found to be a unique catalyst in C-C bond-forming reactions with ketene dithioacetals. Distinctly different from other acids (including Lewis and Brønsted acids), the remarkable catalytic performance of hydrobromic acid in catalytic amounts was observed in the "acid"-catalyzed reactions of readily available functionalized ketene dithioacetals 1 with ...
Jezierny D - - 2010
The study was conducted to validate in vitro prediction of standardised ileal digestibilities (SID) of crude protein (CP) and amino acids (AA) in grain legumes for growing pigs using six different cultivars of faba beans (Vicia faba), six different cultivars of field peas (Pisum sativum), and five different cultivars of ...
Dutta Subrata - - 2011
The autocatalytic photochemical reaction, which is potentially controlled by any selected nucleic acid, is highly sequence specific and not inhibited by its products, was developed. This reaction generates colored and fluorescent products, which can be monitored by the naked eye.
Zill Andrew A Department of Chemistry, University of Illinois, 600 S. Mathews Avenue, Urbana, IL 61801, - - 2011
A one-step, large-scale preparation of alkyne-containing hyper-branched polyglycerols (HPG) is reported. The HPGs undergo click reactions to organic azides allowing a range of applications.
Ashworth Ian W - - 2010
The kinetics of the HCl-catalyzed deprotection of the Boc-protected amine, thioester 2 to liberate AZD3409 1 have been studied in a mixture of toluene and propan-2-ol. The reaction rate was found to exhibit a second-order dependence upon the HCl concentration. This behavior was found to have a degree of generality ...
Terpolilli Marco - - 2011
The irradiation of a series of phenyl sulfonates and phosphates leads to the quantitative release of acidity with a reasonable quantum yield (≈0.2). Products characterization, ion chromatography analysis and potentiometric titration are consistent with the intervening of two different paths in this reaction, viz. cationic with phosphates and (mainly) radical ...
Viu J - - 2010
Acid-base disturbances are traditionally assessed using the Henderson-Hasselbach equation. The simplified strong ion approach describes more accurately the complex acid-base and electrolyte abnormalities present in endurance horses. To describe acid-base and electrolytes changes in fit horses competing in a FEI*** 120 km endurance race and to compare the traditional vs. ...
Houpis Ioannis N - - 2010
The carboxylic acid anion moiety has been used as a tunable directing group in the cross-coupling reaction of 2,6-dichloronicotinic acid and 2,5-dibromo-1,2,4-triazole derivatives producing selectively the 2- or 6-substituted nicotinic acids, while only the 5-substituted triazoles were obtained under a variety of conditions.
Wee Lik H - - 2010
Nanomaterial of Cu(3)(BTC)(2) (BTC = benzene tricarboxylic acid) incorporating Keggin heteropolyacid conveniently prepared at room temperature and recovered by freeze drying outperforms ultrastable Y zeolite in acid catalysed esterification reaction.
Konishi Masa-aki - - 2011
To explore a novel glycolipid, we performed biochemical reactions using a recombinant α-glucosidase from Geobacillus sp. which shows excellent transglycosylation reaction to hydroxyl groups in a variety of compounds. Two different glycolipids (GL-1 and GL-2) were prepared from ricinoleic acid using a recombinant α-glucosidase from Geobacillus sp. The molecular structure ...
Brask Jesper - - 2011
An integrated biodiesel process that combines enzymatic esterification and alkaline transesterification is suggested. With focus on the enzymatic step, the paper provides proof of concept and suggestions for further process development. Hence, palm fatty acid distillate (PFAD) has been enzymatically converted to fatty acid methyl esters in a two-step process ...
Fernández-Alonso Alejandra - - 2010
We investigated the effects of solvent composition, acidity and temperature on the switch between heterolytic and homolytic mechanisms in the course of the butanolysis of 4-methylbenzenediazonium (4MBD) ions in binary BuOH/H(2)O mixtures and in reverse micelles, RMs, composed of n-BuOH, H(2)O and sodium dodecyl sulfate, SDS, by employing a combination ...
Son Sung Mo - - 2011
Esterification of oleic acid was performed in a three-phase fixed-bed reactor with a cation exchange resin catalyst (Amberlyst-15) at high temperature, which was varied from 80 to 120 °C. The fatty acid methyl ester (FAME) yields in the fixed-bed reactor were increased with increases in the reaction temperature, methanol flow ...
Zhu Guangyong - - 2011
Amino acids play an important physiological role in all life-forms and can be recovered from bean dregs waste using sub-critical water hydrolysis. This work deals with the hydrolysis kinetics of bean dregs. Kinetics was conducted in a temperature range of 200-240°C using a 300-ml stainless steel batch reactor. Since the ...
Pippig Falko - - 2010
A new technique for the production of nanoscale polymer networks on surfaces is presented. Bifunctional oligomeric building blocks react with trifunctional linkers and couple to activated polymer surfaces. PEG diamines were used as branch molecules in the network which were linked by either a trifunctional epoxide or a trifunctional acid ...
Suzuki Toshinori - - 2010
When 1,3-dimethyluric acid was treated with a nitric oxide donor, diethylamine NONOate, in an aerobic neutral solution and the reaction was analyzed by HPLC, 1,3-dimethyluric acid was consumed to yield a nitrosated derivative, which decomposed with a half-life of 17.9 min at pH 7.4 and 37 degrees C. When 1,3,7-trimethyluric ...
Gómez-Bombarelli Rafael - - 2011
One group of disinfection byproducts of increasing interest are the halogenated furanones, which are formed in the chlorination of drinking water. Among these halofuranones is mucochloric acid (MCA, 3,4-dichloro-5-hydroxyfuran-2(5H)-one), and mucobromic acid (MBA, 3,4-dibromo-5-hydroxyfuran-2(5H)-one). Both mucohalic acids (MXA) are direct genotoxins and potential carcinogens, with the capacity to alkylate the ...
Zhang Xin - - 2010
We have investigated the fundamental amidation reaction by a model system consisting of an electrochemically functionalised Au surface by aminophenyl and 4-nitrobenzoic acid activated by EEDQ. The development of the NO(2) related stretching vibrations with time reveals that the amidation process is very slow at Au surfaces and is completed ...
Pinzi S - - 2011
Biodiesel is an alternative fuel for diesel engines produced through transesterification of oleaginous feedstocks. To analyze the influence of the fatty-acid composition on biodiesel optimization, transesterification of several vegetable oils has been studied. Reactions were carried out in flasks filled with vegetable oils, heated to the reaction temperature and stirred ...
Kireche Mustapha - - 2010
Compounds slowly releasing formaldehyde, the so-called formaldehyde-releasers, are commonly employed as preservatives in cosmetics instead of free formaldehyde, which is a strong skin sensitizer. It has been long accepted that formaldehyde-releaser sensitization is attributable to released formaldehyde. However, clinical studies show the existence of patients allergic to formaldehyde-releasers but not ...
Nájera Juan J - - 2010
In this paper, a kinetic study of the oxidation of maleic and fumaric acid organic particles by gas-phase ozone at relative humidities ranging from 90 to 93% is reported. A flow of single component aqueous particles with average size diameters in the range 2.6-2.9 µm were exposed to a known ...
Morakinyo Moshood K - - 2010
The metabolic conversion of homocysteine (HCYSH) to homocysteine thiolactone (HTL) has been reported as the major cause of HCYSH pathogenesis. It was hypothesized that inhibition of the thiol group of HCYSH by S-nitrosation will prevent its metabolic conversion to HTL. The kinetics, reaction dynamics, and mechanism of reaction of HCYSH ...
Dai Chaofeng - - 2010
Boronic acids have been widely used in a wide range of organic reactions, in the preparation of sensors for carbohydrates, and as potential pharmaceutical agents. With the growing importance of click reactions, inevitably they are also applied to the synthesis of compounds containing the boronic acid moiety. However, such applications ...
Donatello S - - 2010
The recovery of phosphorus from sewage sludge ash samples obtained from 7 operating sludge incinerators in the UK using a sulfuric acid washing procedure to produce a technical grade phosphoric acid product has been investigated. The influences of reaction time, sulfuric acid concentration, liquid to solid ratio and source of ...
Ogawa Shoujiro - - 2010
(22E)-3alpha,6alpha,7alpha,12alpha-Tetrahydroxy-5beta-chol-22-en-24-oic acid and its N-acylamidated conjugates with glycine or taurine were synthesized from cholic acid. The key reactions employed are: 1) degradation of the side chain in intermediary C(24) 3alpha,6alpha,7alpha,12alpha-tetrahydroxylated bile acid to the corresponding C(22) 23,24-dinor-aldehyde, followed by Wittig reaction with methyl (triphenylphosphoranylidene)acetate and 2) N-acylamidation of the unconjugated ...
Maier Timm - - 2010
In all organisms, fatty acid synthesis is achieved in variations of a common cyclic reaction pathway by stepwise, iterative elongation of precursors with two-carbon extender units. In bacteria, all individual reaction steps are carried out by monofunctional dissociated enzymes, whereas in eukaryotes the fatty acid synthases (FASs) have evolved into ...
Liu Yang - - 2010
A handy, specific, sensitive bioprobe has been developed. Tetraphenylethene (TPE) was functionalized by a maleimide (MI) group, giving a TPE-MI adduct that was nonemissive in both solution and the solid state. It was readily transformed into a fluorogen showing an aggregation-induced emission (AIE) property by the click addition of thiol ...
Calvo Paula - - 2010
Rate constants for acid catalysis of the reactions of N-chlorodimethylamine (1), N-chloro-2,2,2-trifluoroethylamine (2) and N,N-dichlorotaurine (3) with iodide ion were determined in H(2)O at 25 degrees C and I = 0.5 (NaClO(4)). The failure to detect significant catalysis by general acids of chlorine transfer from 1 to the nucleophile, together ...
Ludek Olaf R - - 2010
Obtaining high stereoselectivity in glycosylation reactions is often challenging in the absence of neighboring group participation. In this study, we demonstrate that activation of glycosyl trichloroacetimidate donors with immobilized perchloric acid on silica (HClO(4)-SiO(2)) provides higher alpha-selectivity than trimethylsilyl triflate (TMSOTf) for reactions that do not involve neighboring group participation.
Chen Qingfeng - - 2010
The GH3 family of acyl-acid-amido synthetases catalyze the ATP-dependent formation of amino acid conjugates to modulate levels of active plant hormones, including auxins and jasmonates. Initial biochemical studies of various GH3s show that these enzymes group into three families based on sequence relationships and acyl-acid substrate preference (I, jasmonate-conjugating; II, ...
Li Yong Jie - - 2010
We investigated the condensed-phase reactions of biogenic VOCs with C double bond C bonds (limonene, C(10)H(16), and terpineol, C(10)H(18)O) catalyzed by sulfuric acid by both bulk solution (BS) experiments and gas-particle (GP) experiments using a flow cell reactor. Product analysis by gas chromatography-mass spectrometry (GC-MS) showed that cationic polymerization led ...
Imbesi Selene - - 2010
This is a retrospective study, based on analysis of data from patients with previous adverse drug reactions admitted to the Allergy and Clinical Immunology Division of both the University of Messina and the University of Bari in the last 4 years. We observed five patients: four of them (two males ...
Volochnyuk Dmitriy M - - 2010
A library of fused pyridine-4-carboxylic acids (including pyrazolo[3,4-b]pyridines, isoxazolo[5,4-b]pyridines, furo[2,3-b]pyridines, thieno[2,3-b]pyridines, and pyrido[2,3-d]pyrimidines) was generated by Combes-type reaction of acyl pyruvates and electron-rich amino heterocycles followed by hydrolysis of the ester. The library members were also demonstrated to undergo the standard combinatorial transformations including amide coupling and esterification, as well ...
Zahmatkesh Saeed - - 2011
N,N'-pyromelliticdiimido-di-L-alanine (1), N,N'-Pyromelliticdiimido-di-L-phenylalanine (2), and N,N'-Pyromelliticdiimido-di-L-leucine (3) were prepared from the reaction of Pyromellitic dianhydride with corresponding L-amino acids in a mixture of glacial acetic acid and pyridine solution (3/2 ratio) under refluxing conditions. A series of poly (amide-imide)s containing L-amino acids were prepared from the synthesized dicarboxylic acids with ...
Gao Xiang - - 2010
The fragmentation reactions of N-monoalkyloxyphosphoryl amino acids (N-MAP-AAs) were studied by electrospray ionization tandem mass spectrometry (ESI-MS). The sodiated cyclic acylphosphoramidates (CAPAs) were formed through a characteristic pentacoordinate phosphate participated rearrangement reaction in the positive-ion ESI-MS/MS and HR-MS/MS of N-MAP-AAs, in which the fragmentation patterns were clearly different from those ...
Nakamura Masao - - 2010
The reaction of the amyloid beta peptide (Abeta) with hypochlorous acid and hydroxyl radicals was analysed by spectrophotometry and mass spectrometry. N-acetylmethionine, Abeta25-35 and Abeta1-42 reacted rapidly with hypochlorous acid. The relative reaction rates of N-acetylmethionine and Abeta with hypochlorous acid was in the order N-acetylmethionine > Abeta25-35 > Abeta1-42. ...
Patil Prafulla D - - 2011
This study demonstrated a one-step process for direct liquefaction and conversion of wet algal biomass containing about 90% of water to biodiesel under supercritical methanol conditions. This one-step process enables simultaneous extraction and transesterification of wet algal biomass. The process conditions are milder than those required for pyrolysis and prevent ...
Fu Mingkun M Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, - - 2010
Gas-phase reactivity of a positively charged aromatic σ,σ-biradical (N-methyl-6,8-didehydroquinolinium) was examined toward six aliphatic amino acids and 15 dipeptides by using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR) and laser-induced acoustic desorption (LIAD). While previous studies have revealed that H-atom and NH(2) abstractions dominate the reactions of related monoradicals ...
Kobayashi Takashi - - 2010
In order to synthesize a sugar ester at high concentration, 1,2-O-isopropylidene-α-D-glucofuranose (IpGlc), which is one of the sugar acetals and is more hydrophobic than unmodified glucose, was esterified with palmitic acid at 40°C using immobilized lipase from Candida antarctica in some organic solvents or their mixtures. Acetone + t-butyl alcohol ...
Lin Chih-Hung - - 2010
Several studies have demonstrated that millions of people globally are potentially exposed to volcanic gases. Hydrogen sulfide is a typical gas in volcanic and geothermal areas. The gas is toxic at high concentrations that predominantly affects the nervous, cardiovascular, and respiratory systems. The WHO air quality guideline for hydrogen sulfide ...
Rota Paola - - 2010
An efficient short protocol for the preparation of N-perfluoroacylated glycals of neuraminic acid, by simple short treatment of differently protected N-acetylneuraminic acid with perfluorinated anhydrides in acetonitrile at 135 degrees C, is reported, together with a rationalitazion of the reaction that allows the alternative formation of N-perfluoroacylated 1,7-lactones to be ...
Usai E M - - 2010
In the presence of methyl acetate triglycerides such as vegetable oils are transformed simultaneously into the corresponding fatty acid methyl esters and triacetyl glycerol (triacetin). The reaction, catalyzed by lipases, was studied as a function of some critical parameters, such as type of catalyst, enzyme hydration and immobilization support. The ...
Guo Jun-Min - - 2010
A simple colorimetric method for the differentiation of indoleacetic acid (IAA) and indolebutyric acid (IBA) in plant samples is described. The color change is based upon the reaction between the auxins and p-(dimethylamino)benzaldehyde (PDAB, Ehrlich reagent) following the electrophilic substitution reaction mechanism at the indole ring. Using their different response ...
Nair Vijay - - 2010
A facile NHC-mediated reaction of aromatic aldehydes with carbon dioxide leading to carboxylic acids is described. The present protocol is mechanistically important, and it can serve as a tool for the sequestration of carbon dioxide.
Xu Su-Ying - - 2010
Substantially enhanced monosaccharide fluorescent sensing in aqueous solutions using a simple phenylboronic acid receptor is achieved by coupling the classic strategy based on saccharide-boronic acid interaction with catalytic Suzuki homocoupling reaction.
Liu Xiaoying - - 2010
The reactions of three isomers of phenyl-substituted propene, trans-beta-methylstyrene, alpha-methylstyrene, and allylbenzene, with atomic oxygen adsorbed on Au(111) have been investigated in order to probe the effect of molecular structure on the selectivity for competing oxidation pathways. Temperature programmed reaction experiments show that these three isomers share common features in ...
Mohamed Mona B - - 2010
A facile and fast one-pot microwave irradiation method has been developed to prepare different shapes of gold nanoparticles capped with a mixture of oleylamine and oleic acid. The size, shape, and morphology of the nanocrystals could be tailored by varying the ratio of oleylamine to oleic acid, the microwave time, ...
Zoumpanioti M - - 2010
Lipases from Rhizomucor miehei and Candida antarctica B were immobilized in hydroxypropylmethyl cellulose organogels based on surfactant-free microemulsions consisting of n-hexane, 1-propanol and water. Both lipases kept their catalytic activity, catalyzing the esterification reactions of various phenolic acids including cinnamic acid derivatives. High reaction rates and yields (up to 94%) ...
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