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Results 501 - 550 of 2855
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Cheng Jing-Sheng - - 2013
Pitching ratio has been reported to impact not only on the primary metabolism, but also the secondary metabolism. Comparative metabolomics was used to explore the metabolic responses of Streptomyces lydicus E9 to pitching ratios (1, 10, and 30 %, v/v). We identified more than 120 metabolites involved in glycolysis, tricarboxylic acid ...
Roberts John A S - - 2013
Open circuit potentials were measured for acetonitrile solutions of a variety of acids and their conjugate bases under 1 atm H2. Acids examined were triethylammonium, dimethylformamidium, 2,6-dichloroanilinium, 4-cyanoanilinium, 4-bromoanilinium, and 4-anisidinium salts. These potentials, along with the pKa values of the acids, establish the value of the standard hydrogen electrode ...
Slade Jonathan H - - 2013
The reactive uptake coefficients (γ) of OH by levoglucosan, abietic acid, and nitroguaiacol serving as surrogate compounds for biomass burning aerosol have been determined employing a chemical ionisation mass spectrometer coupled to a rotating-wall flow-tube reactor over a wide range of [OH] ∼10(7)-10(11) molecule cm(-3). Volatilisation products of these organic ...
Nozue Tsuyoshi - - 2013
A low n-3 to n-6 polyunsaturated fatty acid (PUFA) ratio is associated with cardiovascular events. However, the effects of this ratio on coronary atherosclerosis have not been fully examined, particularly in patients treated with different types of statins. This study compared the effects of n-3 to n-6 PUFA ratios on ...
Camerino Michelle A - - 2013
An efficient synthesis of the enantiomers of fluorenylethylchloroformate (FLEC) has been achieved that allows the routine application of the reagent for the resolution of chiral amines including unusual amino acids. The utility of the fluorenylethoxycarbonyl (Feoc) group as a chiral Fmoc equivalent, for combined resolution and protection of amino acids, ...
Sun Qianping - - 2013
Ordered mesoporous γ-alumina (OMA), Ce-doped, Zr-doped and Ce-Zr-codoped OMA samples were synthesized in a sol-gel system with P123 as the soft template, both salicylic acid and citric acid as the assistant templates. The results show that the incorporations of either cerium or zirconium or both are able to improve the ...
Cao Hai - - 2013
Twisted ribbons were formed by the self-assembly of racemic alanine derivatives (middle picture), whereas only flat nanostructures were obtained from the individual enantiomers (left). The twist was sensitive to a slight enantiomeric excess and showed remarkable macroscopic chirality. Moreover, it could discriminate various amino acid derivatives (right) and even enabled ...
Bhoite Roopali N - - 2013
Gallic acid (3,4,5-trihydroxybenzoic acid) was produced by microbial biotransformation of coffee pulp tannins by Penicillium verrucosum. Gallic acid production was optimized using response surface methodology (RSM) based on central composite rotatable design. Process parameters such as pH, moisture, and fermentation period were considered for optimization. Among the various fungi isolated ...
Crisalli Pete P Department of Chemistry, Stanford University, Stanford, California 94305-5080, United - - 2013
Anthranilic acids were recently reported as superior catalysts for hydrazone and oxime formation compared to aniline, the classic catalyst for these reactions. Here, alternative proton donors were examined with varied pKa in an effort to enhance activity at biological pH. The experiments show that 2-aminobenzenephosphonic acids are superior to anthranilic ...
Ahmed Sibtain - - 2013
Detailed kinetic and thermodynamic parameters for lysine production from Brevibacterium lactofermentum are investigated for the first time in this study. Production of the essential amino acid, L-lysine, by B. lactofermentum was assessed in a flask and a continuously stirred tank fermentor (22 L). Maximum lysine production was achieved after 40 h of ...
Mukai Yuri - - 2013
The glycosylphosphatidylinositol (GPI) attachment is a most important post-translational modification of proteins that plays essential roles in promoting the biochemical activities of eukaryotic cells. Described here is an analysis of the amino acid properties of mammalian GPI-anchored proteins (GPI-APs) and the development of an innovative method of detecting them. GPI-APs ...
Gao Haiyan - - 2013
Intergrown Li2FeSiO4·LiFePO4-C nanocomposites with different compositions were synthesized by a tartaric acid assisted sol-gel method. The 0.96Li2FeSiO4·0.04LiFePO4-C nanocomposites exhibited greatly enhanced electrochemical properties, attaining a high discharge capacity up to 284.7 mA h g-1 (equal to ca. 1.72 Li+ per molecule) at 45 °C.
Yin Jie - - 2013
Reduction of the hypervalent heme pigment ferrylmyoglobin by green tea catechins in aqueous solution of pH = 7.5 was investigated by stopped-flow spectroscopy. Reduction by the gallic acid esters epigallocatechin gallate (EGCG, k2 = 1460 L mol-1 s-1, 25.0 °C, 0.16 ionic strength) and epicatechin gallate (ECG, 1410 L mol-1 ...
Chen Zhaohui - - 2013
We reported a new application of silver nanoparticles (NPs) for the visual sensing of aromatic polyphenols, such as gallic acid, pyrogallol and tannic acid, which is based on the intensified plasmon absorbance signals and visual changes from yellow to orange due to hydrogen-bonding recognition and subsequent catalytic oxidation of the ...
Vahl Katja - - 2013
A FIA system using a pH-sensitive detector based on a graphite/quinhydrone/silicone composite electrode was applied to determine sequentially the titratable acidity and the pH of wine, as well as the sum of calcium and magnesium ions. For all measurements the same FIA configuration was used employing different carrier solutions. The ...
Gardette Jean-Luc - - 2013
The oil extracted from the bean of Balanites aegyptiaca was characterized, and its photochemical and thermal stabilization were evaluated. The chemical composition was determined using gas chromatography (GC), revealing that the oil is very rich in unsaturated fatty acids (72% Omega-6 and Omega-9). The photochemical stability was assessed by subjecting ...
Selvan B Karpanai - - 2013
Carbon (neutral) based renewable liquid biofuels are alternative to petroleum derived transport fuels that contribute to global warming and are of a limited availability. Microalgae based biofuels are considered as promising source of energy. Lyngbya sp. and Synechococcus sp. were studied for the possibility of biodiesel production in different media ...
Wen Zhang Z Department of Chemistry, Georgia State University, Atlanta, Georgia 30303, - - 2013
The selenium derivatization of nucleic acids and nucleic acid-protein complexes has provided a powerful tool to solve phase problem in X-ray crystallography. Selenium atoms in the nucleotides can serve as fine scattering centers in crystal diffraction. Towards the synthesis of multiple selenium atom-containing nucleotides, which offers strong phasing power to ...
Singh Suman - - 2013
Thioglycolic acid capped cadmium sulfide (CdS/T) quantum dots have been synthesized using wet chemistry and their optical behavior has been investigated using UV-visible absorption and fluorescence spectroscopy. The role of the capping agent, sulfide source concentration, pH and temperature has been studied and discussed. Studies showed that alkaline pH leads ...
Melling Meaghan A - - 2013
Background: Retinoic acid signaling is essential for many aspects of early development in vertebrates. To control the levels of signaling, several retinoic acid target genes have been identified that act to suppress retinoic acid signaling in a negative feedback loop. The nuclear protein Ski has been extensively studied for its ...
Kul Dilek - - 2013
A new type of modified electrode sensor for ascorbic acid has been prepared by deposition of multi-walled carbon nanotubes (MWCNT) and poly(Nile blue A) on the surface of glassy carbon electrodes. Nile blue A was electropolymerised either beneath (directly on glassy carbon) or onto the MWCNT layer by potential cycling ...
Yun Yeo-Myeong - - 2013
In this study, individual pretreatments (acid and ultrasonic) and a combination of these pretreatments were optimized to enhance the efficiency of dark fermentative hydrogen production (DFHP) from microalgal biomass. The experimental results show that the maximum H2 production performance of 42.1mL H2/g dry cell weight (dcw) was predicted at 0.79% ...
Izumi Yudai - - 2013
Circular dichroism (CD) spectroscopy in the soft x-ray energy region is a new tool to study the local structure of chiral materials. In this paper, we introduce a method to measure high-quality CD spectra in the oxygen K-edge energy region. Characteristic CD spectra of thin films of the amino acids ...
Chen Hsiao-Chien - - 2013
To break through the long time and complex procedures for the preparation of highly conjugated reduced graphene oxide (r-GO) in developing electrochemical sensor, a time-saving and simple method is investigated in this study. One novel step of the exfoliated accompanying carboxylated graphene sheet from pristine is achieved via Friedel-Crafts acylation. ...
Peluso Ilaria - - 2013
BACKGROUND AND AIM: A complex relationship between immune system and metabolic pathway exists and can induce oxidative stress. The objective of this study was to design a new methodology allowing the measurement of oxidative status of leukocytes. METHODS AND RESULTS: We developed a flow cytometry technique, based on C11-BODIPY 581/591 ...
Stefanov Ivan Valentinov - - 2013
Determination of nutritionally important trans MUFA, CLA and OBCFA milk fatty acids (often present in amounts lower than 1.0 g/100g of total fat) using fast and non-destructive analytical methods would enhance their use as diagnostic tools in dairy herd and human health management. Here, PLS regression using ATR/FTIR spectra indicated ...
Chukir Tariq - - 2013
The long-chain 18-carbon fatty acids linoleic, oleic, and stearic acids, retronasally in vapor phase, are discriminated from blanks and each other. However, ability to linguistically identify them was unknown. To explore this, a Focus Group and then Check-All-That-Apply measures gave 9 identifiers for the 3 fatty acids plus phenylethyl alcohol ...
Li Xiao-Ling - - 2013
Different concentrations of a sodium chloride spray were applied to the grapevine cultivar Kyoho to determine the effects of salinity on berry quality. The fruit's fresh weight, relative water content, hardness and titratable acid were gradually enhanced with increased salt concentrations. Anthocyanin and soluble solids increased after treatment with moderate ...
Boros Eszter E The Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, 149 Thirteenth Street, Suite 2301, Charlestown, Massachusetts 02129, United - - 2013
The Gd(III) complex of DO3A-N-α-aminopropionate, Gd(DOTAla), was used to generate a small library of putative MRI probes targeted to human serum albumin (HSA). Ten compounds were synthesized via multistep organic synthesis, and the corresponding Gd complexes were investigated for their affinity to HSA, lipophilicity, and relaxivity in the absence and ...
Wang Hualei - - 2013
ABSTRACT: BACKGROUND: A nitrilase-mediated pathway has significant advantages in the production of optically pure (R)-(-)-mandelic acid. However, unwanted byproduct, low enantioselectivity, and specific activity reduce its value in practical applications. An ideal nitrilase that can efficiently hydrolyze mandelonitrile to optically pure (R)-(-)-mandelic acid without the unwanted byproduct is needed. RESULTS: ...
Kwon Eilhann - - 2013
The concept of Waste-to-Energy (WtE) with regards to the utilisation of byproducts from the bioethanol industry (e.g., distiller's dried grain with solubles: DDGS) was employed to enhance the renewability of biodiesel, which would be an initiative stage of a biorefinery due to the conjunction between bioethanol and biodiesel. For example, ...
Aliani Michel M Department of Human Nutritional Sciences, University of Manitoba Winnipeg, Manitoba, Canada, R3T - - 2013
Ingredients such as ascorbic acid used to preserve redness of the raw meat, and carnosine and ribose used for flavor improvement have been incorporated into minced meats to increase consumer acceptance. The objective of this study was to investigate the possible synergistic effect of ascorbic acid, carnosine, and ribose on ...
White James David - - 2013
The tripeptide (S)-valinyl-(S)-m-hydroxyphenylalanyl-(3S)-piperazate common to immunosupressants sanglifehrins A-D was synthesized from the constituent amino acid residues in nine steps and 42% overall yield via a sequence that began from m-hydroxybenzaldehyde. A key construction was the installation of (S) absolute configuration in m-hydroxyphenylalanine using asymmetric phase-transfer catalysis in the presence of ...
Liu Tiantian - - 2013
A solid acid catalyst, prepared by sulfonating carbonized corn straw, was proved to be an efficient and environmental benign catalyst for the esterification of oleic acid and methanol. Various synthetic parameters, such as carbonization temperature and time were systematically examined. It was found that the catalyst exhibited the highest acid ...
Liang Yi - - 2013
This work was to utilize acetic acid contained in bio-oil for growth and lipid production of the microalga Chlamydomonas reinhardtii. The acetic acid-rich bio-oil fraction derived from fast pyrolysis of softwood contained 26% (w/w) acetic acid, formic acid, methanol, furfural, acetol, and phenolics as identified compounds, and 13% (w/w) unidentified ...
Aggarwal Anupama - - 2013
The electrochemical behavior of dopamine was examined under redox cycling conditions in the presence and absence of a high concentration of the interferent ascorbic acid at a coplanar, microelectrode array where the area of the generator electrodes was larger than that of the collector electrodes. Redox cycling converts a redox ...
An Meiling - - 2013
Chlamydomonas sp. ICE-L which can thrive in extreme environments of the Antarctic is a major biomass producer. The FAD genes in Chlamydomonas sp. ICE-L were obtained and sequence alignment showed that these genes are homologous to known FADs with conserved histidine motifs. In this study, we analyzed the transcription of ...
Lee Songyi - - 2013
A new polydiacetylene oxyphenylboronic acid (PDA-OPBA-1) bearing group was synthesized and showed diverse colorimetric changes, such as yellow, orange, and red, upon the addition of cationic surfactants at pH 7.4. On the other hand, anionic surfactants and simple ammonium salts did not show any color change. Specifically, color changes to ...
Han Qian - - 2013
A chiral interface has been designed for specific recognition of carboxylic acids using multilayer architectures of β-cyclodextrin (β-CD) and methylene blue/reduce-graphene (MB@rGO) on glassy carbon electrodes. The advantages of β-CD as a chiral selector and MB@rGO composite as an electrochemical indicator were perfectly presented in this novel interface. It displayed ...
Ragheb Ragy R T - - 2013
PURPOSE: Combined therapeutic and diagnostic agents, "theranostics" are emerging valuable tools for noninvasive imaging and drug delivery. Here, we report on a solid biodegradable multifunctional nanoparticle that combines both features. METHODS: Poly(lactide-co-glycolide) nanoparticles were engineered to confine superparamagnetic iron oxide contrast for magnetic resonance imaging while enabling controlled drug delivery ...
Lata Suman - - 2013
An improved D-amino acid biosensor was constructed based on covalent immobilization of D-amino acid oxidase onto carboxylated mutliwalled carbon nanotubes/copper nanoparticles/polyalinine hybrid film electrodeposited on Au electrode. The biosensor exhibited optimum response within 2s at pH 8.0 and 30°C, when polarized at 0.09V. There was a linear relationship between biosensor ...
Mat Hadzir Nursyamsyila N Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia. - - 2013
Fatty acid esters are long-chain esters, produced from the reaction of fatty acids and alcohols. They possess potential applications in cosmetic and pharmaceutical formulations due to their excellent wetting behaviour at interfaces and a non-greasy feeling when applied on the skin surfaces. This preliminary work was carried out to construct ...
Ma Bao-Di - - 2013
A novel esterase, rPPE01, from Pseudomonas putida ECU1011 was heterologously expressed in Escherichia coli and identified for enzymatic resolution of hydroxy acids via O-deacetylation. α-Acetoxy carboxylates were converted with approximately 50% yield and excellent enantioselectivity (E>200) at a substrate concentration of 100mM. The half-lives of rPPE01 were 14days at 50°C ...
Yang Wandian - - 2013
Furfural is one of the most promising platform chemicals derived from biomass. In this study, response surface methodology (RSM) was utilized to determine four important parameters including reaction temperature (170-210°C), formic acid concentration (5-25g/L), o-nitrotoluene volume percentage (20-80vt.%), and residence time (40-200min). The maximum furfural yield of 74% and selectivity ...
Maier Michael P - - 2013
Assessing the environmental fate of chiral micropollutants such as herbicides is challenging. The complexity of aquatic systems often makes it difficult to obtain hydraulic mass balances, which is a prerequisite when assessing degradation based on concentration data. Elegant alternatives are concentration-independent approaches like compound-specific isotope analysis or enantiospecific concentration analysis. ...
Song Jae Yang - - 2013
Heterologous expression of a putative K+/H+ antiporter of Streptomyces coelicolor A3(2) (designated as sha4) in E. coli and Streptomyces hygroscopicus JCM4427 showed enhanced tolerance to K+ stress, acidic-pH shock, and/or geldanamycin production under K+ stress. In a series of K+ extrusion experiments with sha4-carrying E. coli deficient in the K+/H+ ...
Hodgson P A - - 2013
Sharp metal tips have many uses, including in scanning probe microscopy. Silver is a particularly interesting metal for plasmonic enhancement, e.g., in tip-enhanced Raman spectroscopy, however few methods for the production of silver tips have been explored. A simple and reliable one step dc electrochemical method for the production of ...
Zoué Lessoy T - - 2013
The search for new sources of oil with improved characteristics has focused our attention on the characterisation of Irvingia gabonensis seed kernel oil. Physicochemical analysis have revealed the following assets: refractive index (1.42 ± 0.00), free fatty acids (2.3 ± 0.8%), peroxide value (3.33 ± 0.57 meq O(2)/kg), iodine value (32.43 ± 1.22 g I(2)/100 g), saponification value (233.75 ± 2.60 mg KOH/g), ...
Ballesta-Claver J - - 2013
A new method for uric acid (UA) determination based on the quenching of the cathodic ECL of the tris(2,2-bipyridine)ruthenium(II)-uricase system is described. The biosensor is based on a double-layer design containing first tris(2,2-bipyridine)ruthenium(II) (Ru(bpy)3(2+)) electrochemically immobilized on graphite screen-printed cells and uricase in chitosan as a second layer. The uric ...
Park J H JH Swine Science and Technology Center, Gyeongnam National University of Science and Technology, Jinju 660-758, - - 2013
Influence of Achyranthes japonica Nakai Extract (AJNE) on properties of pork sausages were studied in the present investigation. AJNE was added to sausages alone or in combination with ascorbic acid to obtain a comparative analysis on properties of control and ascorbic acid added-sausages. Results showed that addition of 0.05% AJNE ...
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