bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and Validation of a Liquid Chromatography-UV Detection Method for the Determination of Sulfonamides in Fish Muscle and Shrimp According to European Union Decision 2002/657/EC
Authors: Granja Rodrigo H M M , de Lima Andreia C , Salerno Alessandro G , Wanschel Amarylis C B A 
Published: February 2013

Abstract
Sulfonamides are one class of antimicrobial agents used in aquaculture production. Sulfonamides are often overused because they are inexpensive and readily available. Their presence at a concentration above the legal limits is a potential hazard to human health. Brazilian authorities have included in the National Regulatory Monitoring Program the control of the three most widely used sulfonamides in aquaculture production, i.e., sulfathiazole, sulfamethazine, and sulfadimethoxine. An LC method with UV detection for the determination of residual sulfonamides in fish muscle, using sulfapyridine as an internal standard has been developed and validated. The validation was performed according to the Brazilian Regulation 24/2009 (equivalent to European Union Decision 2002/657/EC). The method meets the Brazilian regulatory requirement that establishes criteria and procedures for determination of parameters such as decision limit (CCα), detection capability (CCβ), precision, and recovery. For fish muscle, CCα was determined at 3.63, 2.91, and 7.46 μg/kg for sulfathiazole, sulfamethazine, and sulfadimethoxine, respectively. CCβ was 9.39, 14.54, and 9.39 μg/kg for sulfathiazole, sulfamethazine, and sulfadimethoxine, respectively. For shrimp, CCα was 11.5, 8.67, and 4.46 μg/kg for sulfathiazole, sulfamethazine, and sulfadimethoxine, respectively. CCβ was 18, 11.93, and 5.24 μg/kg for sulfathiazole, sulfamethazine, and sulfadimethoxine, respectively. A complete statistical analysis was performed on the results obtained. The results indicate that the method is robust when subjected to day-to-day analytical variations.
Determination of 30 Synthetic Food Additives in Soft Drinks by HPLC/Electrospray Ionization-Tandem Mass Spectrometry
Authors: Gao Hui , Yang Minli , Wang Minglin , Zhao Yansheng , Cao Ya , Chu Xiaogang 
Published: February 2013

Abstract
A method combining SPE with HPLC/electrospray ionization-MS/MS was developed for simultaneous determination of 30 synthetic food additives, including synthetic colorants, preservatives, and sweeteners in soft drinks. All targets were efficiently separated using the optimized chromatographic and MS conditions and parameters in a single run within 18 min. The LOD of the analytes ranged from 0.01 to 20 μg/kg, and the method was validated with recoveries in the 80.8 to 106.4% range. This multisynthetic additive method was found to be accurate and reliable and will be useful to ensure the safety of food products, such as the labeling and proper use of synthetic food additives in soft drinks.
Modifications of AOAC Official Method 999.15 to Improve the Quantitation of Vitamin K1 in Complex Formulated Nutritional Products
Authors: Delmonte Pierluigi , Barrientos Steven , Rader Jeanne I 
Published: February 2013

Abstract
Vitamin K1 (phylloquinone) occurs in foods in relatively low concentrations. It is synthesized for addition to formulated nutritional products (infant formulas, medical foods, and adult nutritional products). In recent years, nutritional products formulated with free amino acids and partially hydrolyzed proteins have been introduced in the market. Schimpf et al. demonstrated that the current AOAC Official Method 999.15 for determination of vitamin K in milk and infant formula is not adequate to quantitatively extract vitamin K1 from such products. We developed a modification of AOAC 999.15 for the analysis of vitamin K1 in these products that provides quantitative extraction by increasing the sample size, volume of extraction solvents, time of liquid/liquid partitioning, and order of the addition of solvents. This modified procedure showed extraction efficiency comparable to that of the original AOAC 999.15 procedure for analyzing infant formula matrixes and to the modified procedure of Schimpf et al. for the analysis of samples containing limited amounts of free amino acids and/or partially hydrolyzed proteins. Extraction efficiency increased more than 10% using the modified extraction procedure for samples containing higher amounts of these components. The chromatographic separation was improved by using a Dionex Acclaim triacontanol-bonded C30 column (250 × 3.0 mm id, 3 μm particle size) maintained at 15°C, with acetonitrile–methanol (50 + 50, v/v) mobile phase at a flow rate of 0.5 mL/min, which provided baseline separation of the cis and trans isomers of vitamin K1 from each other and from other compounds contained in the sample extracts.
EL4 Cell-Based Colorimetric Toxin Neutralization Activity Assays for Determination of Neutralizing Anti-Ricin Antibodies
Authors: Lindsey Changhong Y , Brown J Edward , Torabazar Nahid R , Smith Leonard A 
Published: February 2013

Abstract
A recombinant ricin toxin A-chain 1-33/44-198 vaccine (RVEc™), developed at the United States Army Medical Research Institute of Infectious Diseases as a vaccine candidate, is under investigation in a phase 1 clinical study. To effectively evaluate the immunogenicity of this ricin vaccine and to eliminate the use of radioactive material, an EL4 cell-based colorimetric toxin neutralization activity (TNA) assay using a CellTiter 96® AQueous One Solution Cell Proliferation Assay Reagent has been developed, optimized, and applied in the vaccine efficacy studies. The TNA assay measures the protective neutralizing anti-ricin antibodies in animal sera by determining the cell viability after ricin exposure in the assay system and comparing it to a purified mouse polyclonal anti-ricin IgG standard curve. The standard curve of the anti-ricin TNA assay closely fits a four-parameter logistic regression model. The unknown test sample concentration was expressed as μg/mL, but not the 50% effective concentration (EC50), which was determined by most TNA assays. The neutralizing endpoint titers, not the 50% effective dilution (ED50), of human specimens were measured with the TNA assay in support of the clinical study of the RVEc vaccine. The optimal amount of ricin toxin, EL4 cells, and concentration of standards used in the assay system was established to minimize false-negative and false-positive results of serum specimens from the nonclinical and clinical studies of RVEc. The testing conditions were adjusted to optimize assay performance. The colorimetric TNA assay replaced a radioactive TNA assay previously used in the ricin vaccine studies.
Immunosensor Based on Electrogenerated Chemiluminescence Using Ru(bpy)32+‐Doped Silica Nanoparticles and Calix[4]crown‐5 Self‐Assembled Monolayers
Authors: Kim Yang‐Rae , Seo Hyo‐Ju , Oh Jeong‐Wook , Lim Hyunchang , Kim Tae Hyun , Kim Hasuck 
Published: February 2013

AbstractAn electrogenerated chemiluminescence (ECL)‐based immunosensor for the detection of immunoglobulin G (IgG) has been fabricated using Ru(bpy)32+‐doped silica nanoparticles and calix[4]crown‐5 self‐assembled monolayers (SAMs). Ru(bpy)32+‐doped silica nanoparticles are prepared by the water‐in‐oil (W/O) microemulsion method. ProLinker B, a commercially available thiolated calix[4]crown‐5 derivative, is utilized for the immobilization of anti‐immunoglobulin G (Anti‐IgG) on a gold electrode. The concentration of IgG is measured using a sandwich‐type ECL immunosensor based on the proposed immunosensor. The ECL intensity is linearly proportional to the IgG concentration over the concentration range 5–30 µg mL−1. The detection limit of IgG is 1.5 µg mL−1.
Enhancement of laser desorption ionization mass spectrometric signals of cesium iodide by elemental sulfur
Authors: Kruegel Andrew , Pavlov Julius , Attygalle Athula B. 
Published: February 2013

RATIONALEThe utility of elemental sulfur as a matrix for inorganic salts such as CsI, AgI, and KI was investigated because the conventional matrices deployed to generate gaseous ions from organic compounds, upon irradiation with a laser beam, are not suitable for inorganic salts.METHODSSulfur and inorganic salts were admixed and irradiated with a 337‐nm UV laser. Laser desorption ionization (LDI) mass spectra were recorded in both positive and negative ion mode on a time‐of‐flight mass spectrometer.RESULTSThe positive ion laser desorption ionization mass spectrum of CsI showed peaks at m/z 133, 393, etc. for [(CsI)nCs]+ ions. Similarly, negative ion spectra showed peaks at m/z 387, 647, etc. for [(CsI)nI]– ions. However, for n >2 ion clusters, the intensities of peaks were negligibly small in both ionization modes. In contrast, spectra recorded from CsI admixed with elemental sulfur showed peaks up to n = 13 for (CsI)nCs+, and n = 9 for (CsI)nI–. A similar enhancement of ion abundances by sulfur was observed for the cluster ions generated from KI and AgI.CONCLUSIONSThe dramatic increase in intensities of the higher‐mass CsI cluster peaks suggests that sulfur acts as a laser‐absorbing matrix for inorganic salts far superior to conventional matrices such as 2,5‐dihydroxybenzoic acid and α‐cyano‐4‐hydroxycinnamic acid. Copyright © 2013 John Wiley & Sons, Ltd.
Reduced Heart Rate Variability Is Associated With Increased Arterial Stiffness in Youth With Type 1 Diabetes
Authors: Jaiswal Mamta , Urbina Elaine M. , Wadwa R. Paul , Talton Jennifer W. , D’Agostino Ralph B. , Hamman Richard F. , Fingerlin Tasha E. , Daniels Stephen R. , Marcovina Santica M. , Dolan Lawrence M. , Dabelea Dana 
Published: February 2013

OBJECTIVE
Reduced heart rate variability (HRV) and increased arterial stiffness (AS) are both present in youth with type 1 diabetes. However, it is unclear whether they are associated and whether their association is independent of cardiovascular disease (CVD) risk factors.

RESEARCH DESIGN AND METHODS
The SEARCH Cardiovascular Disease (SEARCH CVD) study explored the cross-sectional relationships between HRV and several measures of AS in youth with (n = 344) and without (n = 171) type 1 diabetes. The SphygmoCor device (AtCor Medical, Sydney, Australia) was used to measure HRV using SD of normal R-R interval (SDNN), as well as AS, using pulse wave velocity in the carotid to femoral segment (PWV-trunk) and augmentation index adjusted to a heart rate of 75 bpm (AIx75). Brachial distensibility (BrachD), another index of AS, was measured with a DynaPulse instrument (Pulse Metric, San Diego, CA). Multiple linear regression analyses explored the associations between HRV and each of the three AS measures, after adjusting for demographic characteristics and traditional CVD risk factors (blood pressure, lipids, obesity, microalbuminuria, and smoking) separately, for youth with and without type 1 diabetes.

RESULTS
Among youth with type 1 diabetes, lower SDNN was associated with peripheral AS (lower BrachD, P = 0.01; r2 = 0.30) and central AS (higher PVW-trunk, P &lt; 0.0001; r2 = 0.37; and higher AIx75, P = 0.007; r2 = 0.08). These associations were attenuated with adjustment for CVD risk factors, but remained statistically significant for BrachD and PWV-trunk. While a similar association between HRV and BrachD was present in control youth, lower HRV was not associated with increased central AS or with AIx75.

CONCLUSIONS
Longitudinal studies are needed to understand the pathways responsible for these associations.
Mineral element content in prized matsutake mushroom (Tricholoma matsutake) collected in China
Authors: Li Tao , Zhang Ji , Shen Tao , Shi Yun-Dong , Yang Shao-Bing , Zhang Ting , Li Jie-Qing , Wang Yuan-Zhong , Liu Hong-Gao 
Published: February 2013

AbstractThe contents of Ca, Cu, Fe, K, Mg, Mn, Na, and Zn in fruiting bodies of the highly-prized matsutake mushroom (Tricholoma matsutake) from twelve widely separated sites in Southwest China were determined using AAS. The results for dried mushrooms showed that the mean contents (mg kg−1) of the determined elements decreased in the following order: K (440–2000), Na (150–740), Ca (90–850), Mg (90–680), Zn (20–180), Fe (13–78), Cu (0.34–45), Mn (0.09–7.6).
Sequestration of supercritical CO2 by mercury oxide
Authors: Xhaxhiu Kledi , Saraçi Erisa , Bente Klaus 
Published: February 2013

AbstractHgCO3·2HgO (mercury oxide carbonate), along with partly unreacted reactants, was obtained by exploring the behaviour of the Hg2Cl2/HgO binary system in supercritical CO2 (scCO2) at 200°C, 22000 kPa in the presence and absence of water, using a self-made laboratory-scale system. The reaction of pure HgO with scCO2 aimed at the synthesis of HgCO3 (mercury carbonate), also yielded the same product. Meanwhile, with a small amount of water present in the Hg2Cl2/HgO-scCO2 system, at 200°C, 22000 kPa, the mineral terlinguaite (Hg4O2Cl2) was obtained instead of mercury oxide carbonate. Repeating this reaction under the same conditions, but in the absence of CO2, again resulted in the synthesis of terlinguaite, leading to the assumption that the scCO2 had no influence on the synthesis of terlinguaite. This study reveals a new moisture-free laboratory method and conditions for the permanent fixation of CO2 by HgO. This method bears two benefits: 1) it can be introduced to reduce the Hg content in flue gas and fly ash emitted from coal-burning power plants and municipal waste incinerators; 2) it can contribute to CO2 mineralisation in montroydite (HgO) geological formations as mercury oxide carbonate.
Mesoporous nanocrystalline MgAl2O4: A new heterogeneous catalyst for the synthesis of 2,4,6-triarylpyridines under solvent-free conditions
Authors: Safari Javad , Zarnegar Zohre , Borujeni Mahmoud 
Published: February 2013

AbstractIn this paper, one-pot synthesis of 2,4,6-triarylpyridine by condensation of subsisted acetophenone (II), aromatic aldehydes (I), and ammonium acetate (III) in the presence of nanocrystalline MgAl2O4 as a new heterogeneous catalyst under solvent-free conditions is reported. Advantages of this method are the use of spatially-hindered aldehydes such as 2-methoxy-, 2-fluoro-, and 2-chlorobenzaldehydes, a new nanocatalyst with high surface area, shorter reaction time, easier workup, higher yield, and its environmental friendliness. The performance of this reaction under solvent free conditions using heterogeneous catalysts like MgAl2O4 could enhance its efficiency from an economic as well as green chemistry point of view.
Synthesis in water-free DMF, characterization, electrical, and gas sensing properties of bis[2-(2-aminoethylamino)ethanol]copper(II) dibromide
Authors: Taşcıoğlu Sülin , Yalçın Bahattin , Dumludağ Fatih , Kakı Esra 
Published: February 2013

Abstract2-(2-Aminoethylamino)ethanol (L) reacts with cupric bromide in dimethylformamide to give a mononuclear complex of Cu(II) [L2Cu]Br2, with six-coordinate distorted octahedral geometry, in which two molecules of tridentate (N,N,O) ligand are involved. The structure was confirmed by spectroscopic methods, elemental and thermogravimetric analyses, and magnetic measurements. Optimization of possible configurations indicated the formation of the trans structure of the complex. Experimental results indicate that the investigated complex, bis[2-(2-aminoethylamino)ethanol] copper(II) bromide, behaves as a semiconductor in the studied temperature range of 298–388 K. Gas sensing properties of the film for the volatile organic compounds (VOCs): acetone, tetra-chloromethane, chloroform, ethanol, and methanol, were also investigated as a function of vapor concentration and temperature in dark. The film showed maximum sensitivity to tetrachloromethane and ethanol vapors at room temperature. Responses of the film to the tested gases are reversible.
Atomic‐Scale Probing the Priority of Oxidation Sites of an Organic Molecule Adsorbed at the CuO/Cu(1 1 0) Interface
Authors: Sheng Kai , Kong Huihui , Li Zhiwen , Zhang Chi , Sun Qiang , Tan Qinggang , Pan Yunxiang , Hu Aiguo , Xu Wei 
Published: February 2013

AbstractCatalytic reactions occurring on oxide‐supported Cu and Cu‐supported oxide catalysts are of fundamental interest in both industrial and scientific fields. Though the interface between Cu and oxide species has been regarded as the reaction site, the exact role of the interface in the catalytic reactions is not fully understood yet. In this work, by using a model system including CuO chains supported on Cu(1 1 0) and an organic molecule with alkynyl and aldehyde groups, we attempted to obtain a fundamental understanding of the role of the interface in the catalytic reactions. A combination of high‐resolution scanning tunneling microscopy imaging and density functional theory calculations provided direct evidence at the atomic scale that the interface between the CuO chains and the Cu(1 1 0) surface is the most favorable site for the adsorption and activation of organic molecules, and the oxygen of CuO has an activity to oxidize both the alkynyl and aldehyde groups of the molecules adsorbed at the interface.
A Solid‐State Electrochemiluminescence Ethanol Biosensor Based on Electrogenerated Poly(pyrrole‐tris(2,2′‐bipyridyl)ruthenium(II)) Film/Alcohol Dehydrogenase/Laponite Composite
Authors: Gao Bu‐Hong , Ding Shou‐Nian , Wang Yi‐Hong , Dai Yunqian , Xia Jiangyan , Sun Yue‐Ming , Cosnier Serge 
Published: February 2013

AbstractBased on the solid‐state electrochemiluminescence (ECL) of an electrogenerated polypyrrole tagged with tris(2,2′‐bipyridyl)ruthenium(II) complex ( denoted as polypyr‐Ru), a new ethanol biosensor was fabricated by casting the composite of alcohol dehydrogenase (ADH) and laponite colloids onto the polypyr‐Ru /Pt electrode. The two layer structure keeps the good robustness of the biosensor due to the electrostatic interaction between the negatively charged biocomposite coating and the positively charged polypyr‐Ru. The morphology of the laponite‐ADH composite coating is characterized by scanning electron microscopy. The electrochemical and ECL properties of the modified electrodes are investigated by cyclic voltammetry. The parameters concerning the ECL biosensor such as the amount of enzyme usage, the appropriate pH are optimized. The resulted ECL biosensor shows a good performance to detect ethanol.
Polyaniline‐Based Sensor Material for Potentiometric Determination of Ascorbic Acid
Authors: Milakin K. A. , Korovin A. N. , Moroz E. V. , Levon K. , Guiseppi‐Elie A. , Sergeyev V. G. 
Published: February 2013

AbstractPolyaniline (PANI)‐based sensor material for determination of ascorbic acid was synthesized by oxidative chemical polymerization of aniline on a screen‐printed carbon‐paste electrode. The influence of PANI chemical structure formed under various polymerization conditions on the sensor response was investigated. The presence of aniline dimer derivatives in PANI structure was found to induce significant improvement of the limit of detection and the linear dynamic range without a change in sensitivity. The sensor prepared by aniline polymerization in pH 7 buffer leading to the product containing mainly the aniline dimer‐based units showed the best detection limit of 0.1 µM. It was shown that the PANI‐based sensor could be used for ascorbic acid analysis in the presence of citrate and lactate as interfering ions. A quantitative determination of ascorbic acid concentration in beverages and vitamins was performed.
Sampling stored‐product insect pests: a comparison of four statistical sampling models for probability of pest detection
Authors: Elmouttie David , Flinn Paul , Kiermeier Andreas , Subramanyam Bhadriraju , Hagstrum David , Hamilton Grant 
Published: February 2013

AbstractBackgroundDeveloping sampling strategies to target biological pests such as insects in stored grain is inherently difficult owing to species biology and behavioural characteristics. The design of robust sampling programmes should be based on an underlying statistical distribution that is sufficiently flexible to capture variations in the spatial distribution of the target species.ResultsComparisons are made of the accuracy of four probability‐of‐detection sampling models – the negative binomial model,1 the Poisson model,1 the double logarithmic model2 and the compound model3 – for detection of insects over a broad range of insect densities. Although the double log and negative binomial models performed well under specific conditions, it is shown that, of the four models examined, the compound model performed the best over a broad range of insect spatial distributions and densities. In particular, this model predicted well the number of samples required when insect density was high and clumped within experimental storages.ConclusionsThis paper reinforces the need for effective sampling programs designed to detect insects over a broad range of spatial distributions. The compound model is robust over a broad range of insect densities and leads to substantial improvement in detection probabilities within highly variable systems such as grain storage. © 2013 Society of Chemical Industry
Volatile compounds from leaves of the African spider plant (Gynandropsis gynandra) with bioactivity against spider mite (Tetranychus urticae)
Authors: Nyalala S.O. , Petersen M.A. , Grout B.W.W. 
Published: February 2013

AbstractPrevious studies have demonstrated that Gynandropsis gynandra emits acetonitrile as a foliar volatile from intact plants and isolated leaves, and that this compound is an effective spider mite repellent. This study has used gas chromatography–mass spectrometry to investigate volatile compounds emitted from homogenised G. gynandra leaves to evaluate their tissue acetonitrile content and to look for other compounds that might be exploited for the management of spider mites. Acetonitrile was absent from the homogenised tissues of five lines of G. gynandra, studied over two seasons. Thirteen volatile compounds were emitted by G. gynandra at significantly higher levels than mite‐susceptible pot roses, including isothiocyanates, aldehydes, esters, alcohols and terpenes. Six representative compounds were selected to assess bioactivity. Spider mite populations were completely inactive after a 2 h exposure to butyl isothiocyanate, 2,4‐heptadienal or β‐cyclocitral, when evaporated from 0.5 µL of pure compound in a 100 mL air space. The same level of inactivity was achieved after exposure to 5.0 μL of (Z)‐2‐pentenol or a 25 μL volume of 50% v/v Z‐3‐hexenal or 5% w/v methyl isothiocyanate. Dissipation of β‐cyclocitral following 24 h exposure to its concentration of 5 μL in a 100 mL air space resulted in a 6% recovery of the spider mites but at higher concentrations no recovery was observed. These identified compounds may have potential as extracted products for management of spider mites in roses, and a high constitutive content of them in roses may be of value in targeted plant breeding for enhanced insect resistance. The range of isothiocyanates found in G. gynandra accounts for the bitter taste of the leaves when used as a traditional vegetable in Eastern Africa and provides a target for manipulation to improve palatability.
Low dose decitabine in very high risk relapsed or refractory acute myeloid leukaemia in children and young adults
Authors: Phillips Christine L. , Davies Stella M. , McMasters Richard , Absalon Michael , O'Brien Maureen , Mo Jun , Broun Randall , Moscow Jeffrey A. , Smolarek Teresa , Garzon Ramiro , Blum William , Schwind Sebastian , Marcucci Guido , Perentesis John P. 
Published: February 2013

SummaryLow‐dose decitabine has encouraging activity and tolerability in adults with acute myeloid leukaemia (AML), but paediatric experience is lacking. We report our retrospective experience with decitabine in eight children and young adults (median age 4 years) with refractory/relapsed AML, who had failed multiple regimens or were not candidates for standard retrieval regimens due to prior toxicities. Three of eight patients (38%) had complete response (CR; 1 each of CR, CR with incomplete platelet recovery and CR with incomplete count recovery). Best responses were observed after a median of 2·5 cycles (range 1–4 cycles). Four patients received subsequent allogeneic stem cell transplant, and two remain in long‐term CR.