bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of Trace Inorganic Mercury Species in Water Samples by Cloud Point Extraction and UV-Vis Spectrophotometry
Authors: Ulusoy Halil İbrahim 
Published: February 2014

Abstract
A new micelle-mediated extraction method was developed for preconcentration of ultratrace Hg(II) ions prior to spectrophotometric determination.2-(2′-Thiazolylazo)-p-cresol (TAC) and Ponpe 7.5 were used as the chelating agent and nonionic surfactant, respectively. Hg(II) ions form a hydrophobic complex with TAC in a micelle medium. The main factors affecting cloud point extraction efficiency, such as pH of the medium, concentrations of TAC and Ponpe 7.5, and equilibration temperature and time, were investigated in detail. An overall preconcentration factor of 33.3 was obtained upon preconcentration of a50 mL sample. The LOD obtained under the optimal conditions was 0.86 μg/L, and the RSD for five replicate measurements of 100 μg/L Hg(II) was 3.12%. The method was successfully applied to the determination of Hg in environmental water samples.
New HPLC and Fluorometric Methods for the Determination of Pyriproxyfen and Pyridalyl Insecticide Residues in Tomatoes
Authors: Farouk Maha , Hussein Lobna A , El Azab Noha F 
Published: February 2014

Abstract
Two sensitive, selective, and precise methods for the determination of pyriproxyfen and pyridalyl insecticide residues in tomatoes have been developed. The first method is HPLC with UV detection in which pyriproxyfen and pyridalyl were extracted with ethyl acetate and acetone, respectively, followed by cleanup using column chromatography. The recoveries ranged from 86.03 to 94.55 for pyriproxyfen and 95.08 to 99.38% for pyridalyl in tomato samples. The LOD of the method was 0.217 ppmfor pyriproxyfen and 0.1866 ppm for pyridalyl. The second method depends on direct fluorometric determination of pyriproxyfen and pyridalyl in acetic and sulfuric acid at excitation and emissionwavelengths of 320 and 646 nm, respectively. The recoveries of pyriproxyfen and pyridalyl in tomato samples ranged from 88 to 98% and 86 to 93%, respectively. The LOD of the method was 0.146 ppm forpyriproxyfen and 0.078 ppm for pyridalyl.Both methods were applied successfully to determine residues and rate of disappearance of pyriproxyfen andpyridalyl from tomatoes.
Variations in the Contents of Gingerols and Chromatographic Fingerprints of Ginger Root Extracts Prepared by Different Preparation Methods
Authors: Liu Mei , Xia Xinhua , Chou Guixin , Liu Dong , Zuberi Aamir , Ye Jianping , Liu Zhijun 
Published: February 2014

Abstract
In the present study, an HPLC-DAD method was optimized for the quantitative determination of 6-gingerol, 6-shogaol, 8-gingerol, and 10-gingerol in gingerextracts. A chromatographic fingerprinting method was also established to differentiate and evaluate theginger extracts for bioactivity. Twenty-one extractswere prepared by methods differing in ginger type (fresh versus dried), solvent, and extraction methods.The ANOVA analysis showed the methods' influence on the mean extraction yields of gingerols increased inthe order of: high pressure-high temperature (HP)&gt;blender (BD)&gt;low pressure (LP). The optimal solvent to extract gingerols was found to be 95% ethanol. The type of ginger used had significant effects onthe content of gingerols, but its overall influence depended on the solvent used. In order to maximize the extraction efficiency of gingerols, a combinationof dry ginger, 95% ethanol, and the HPextraction method should be employed. The chromatographic fingerprints were obtained to differentiate the unknown components from all ginger extracts. The similarity of the chromatographic fingerprints was used to evaluatethe differences among all extracts. It can be concluded that the chromatographic fingerprints are able to ensure the stability of each extract and have somecorrelation with the observed bioactivity.
A Statistical Model for Assessing Performance Standards for Quantitative and Semiquantitative Disinfectant Test Methods
Authors: Parker Albert E , Hamilton Martin A , Tomasino Stephen F 
Published: February 2014

Abstract
A performance standard for a disinfectant test method can be evaluated by quantifying the (Type I) pass-error rate for ineffective products and the (TypeII) fail-error rate for highly effective products. This paper shows how to calculate these error rates for test methods where the log reduction in a microbial population is used as a measure of antimicrobial efficacy. The calculations can be used to assess performance standards that may require multiple tests of multiple microbes at multiple laboratories. Notably, the error rates account for among-laboratory variance of the log reductions estimated from a multilaboratory data set and the correlation among tests of different microbes conducted in the same laboratory.Performance standards that require that a disinfectant product pass all tests or multiple tests on average, are considered. The proposed statistical methodology is flexible and allows for a different acceptable outcome for each microbe tested, since, for example, variability may be different for different microbes. The approach can also be applied to semiquantitative methods for which product efficacy is reportedas the number of positive carriers out of a treated set and the density of the microbes on control carriers is quantified, thereby allowing a log reduction to be calculated. Therefore, using the approach described in this paper, the error rates can also be calculated for semiquantitative method performance standards specified solely in terms of the maximum allowable number of positive carriers per test. The calculations are demonstrated in a case study of the current performance standard for the semiquantitative AOAC Use-Dilution Methods for Pseudomonas aeruginosa (964.02) and Staphylococcus aureus (955.15), which allow up to one positive carrier out of a set of 60 inoculated and treated carriers in each test. A simulation study was also conducted to verify the validity of the model's assumptions and accuracy. Our approach, easily implemented using the computer code provided, offers a quantitative decision-making tool for assessing a performance standard for any disinfectant test method for which log reductions can be calculated.
Use of Statistical Modeling to Reassess the Performance Standard for the AOAC Use-Dilution Methods (955.15 and 964.02)
Authors: Tomasino Stephen F , Parker Albert E , Hamilton Martin A 
Published: February 2014

Abstract
The AOAC Use-dilution methods (UDM) 955.15 (Staphylococcus aureus) and 964.02 (Pseudomonas aeruginosa) are laboratory methods used to substantiate antimicrobial efficacy claims for liquid disinfectants on inanimate surfaces. The UDM is accepted by the U.S. Environmental Protection Agency for the purpose of product registration. To attain a hospital-level claim, testing against S. aureus and P. aeruginosa is required, and the product must pass against both microbes. Currently, the UDM's performance standard for a single 60-carrier test is the same for both microbes, and allows up to one positive carrier for the product to be considered as a pass. In this paper, the performance standards for these methods are reassessed using data from a 2009 five-laboratory collaborative study and a recently published statistical model. The reassessment focuses on the pass-error rate for ineffective products and the fail-error rate for highly effective products. The calculations indicate that the pass-error rate is between 9 and 24% and the fail-error rate between 18 and 23%when the current performance standard is used for a single test. For product registration, a smaller pass-error rate (1%) historically has been maintained by requiring that a disinfectant pass three UDM testsfor each of the two microbes; however, the calculations also indicate that the fail-error rate is between 42 and 45%. This large fail-error rate is a compelling reason to consider a new performance standard for the two UDM methods, 955.15 (S. aureus) and 964.02 (P. aeruginosa).One alternative performance standard allows no more than six positive carriers out of 60 as a pass when using P. aeruginosa and no more than three positive carriers out of 60 when using S. aureus. In addition, the new performance standard requires that three UDM tests be performed with each of the two microbes, and the disinfectant must pass all six tests to be considered efficacious. The statistical calculations for this alternative performance standard indicate that the pass-error rate is no more than 3%, while the fail-error rateis as small as 5%. Based on these error rate calculations, proposed revisions to the performance standards for AOAC Methods 955.15 and 964.02 are provided.
Experimental Design in Analytical Chemistry—Part II: Applications
Authors: Ebrahimi-Najafabadi Heshmatollah , Leardi Riccardo , Jalali-Heravi Mehdi 
Published: February 2014

Abstract
This paper reviews the applications of experimental design to optimize some analytical chemistry techniques such as extraction, chromatography separation, capillary electrophoresis, spectroscopy, and electroanalytical methods.
Chansons et cannabis : représentations sociales, enjeux identitaires et communicationnels
Authors: Dany Lionel 
Published: February 2014

Les communications culturelles participent à rendre « visibles » les objets sociaux et contribuent à les inscrire et à en rendre compte dans un contexte social. Ainsi, l’analyse de produits culturels tels que les chansons peut s’avérer pertinente dans une perspective qui viserait à explorer des représentations sociales. Nous avons effectué l’analyse de contenu de vingt-cinq chansons françaises ayant pour thème le cannabis. Les propos véhiculés témoignent d’une expérience pouvant être rapprochée de celle des consommateurs. Autrement dit, ces chansons expriment bien « quelque chose » qui est de l’ordre de la situation sociale du consommateur dans un ensemble complexe qui fait intervenir divers contextes socionormatifs. De plus, l’omniprésence d’un autrui « pensé » et « agi », en référence à l’objet représenté, fait intervenir des processus de croyances de groupe qui permettent de déchiffrer ce qui est de l’ordre de l’intentionnalité de l’oeuvre. L’analyse de communications culturelles comme les chansons se révèle tout à fait pertinente et heuristique pour appréhender de manière contextuelle les formes de savoir de sens commun et pour saisir certains enjeux propres à leur élaboration.
Les drogues dans le projet autobiographique de Mötley Crüe
Authors: Laurin Hélène 
Published: February 2014

La présence des drogues dans la musique populaire – le rock, tout particulièrement – n’a pas souvent été étudiée. Nous savons que lesmedicine showsdu XIXesiècle et du début du XXesiècle, soit des spectacles ambulants vantant les vertus de différents médicaments, composés d’opiacés, de cocaïne ou d’alcool, ont contribué à faire du musicien un personnage voyageur, sans attache et aucunement ennuyé par les conventions sociales. De plus, les différentes lois sur les drogues entrées en vigueur aux États-Unis à partir de 1915 ont façonné la « toxicomanisation » des musiciens en en faisant des figures « hors la loi » et rebelles. Dans cet article, nous analysons comment les musiciens, eux-mêmes, comprennent leur consommation de drogues à travers leurs récits autobiographiques en prenant comme exemple le groupe Mötley Crüe. Ce groupeglam metal, très populaire au courant des années 1980, au style de vie décadent, présente candidement sa consommation de drogues dans son projet autobiographique qui est composé de six autobiographies publiées depuis 2001. En somme, selon leurs récits de vie, les membres du groupe consomment abondamment et au nom de « la fête », même si leur santé et leur intégrité physique (tout comme celles des autres) sont mises en péril. Pour quelles raisons continuent-ils à consommer autant de drogues s’ils s’humilient et se blessent ? En fait, la rébellion est une composante essentielle de l’identité même de Mötley Crüe et elle se construit à travers la consommation ostentatoire de drogues des membres du groupe. Cependant, leur rébellion constitue un individualisme extrême, une « bourgeoisie radicale » en quelque sorte, ne changeant absolument rien au fonctionnement de ce qu’ils affirment vouloir bouleverser, contribuant ainsi à la dépolitisation du rock.
Preparation and Use of Reverse Protein Microarrays
Authors: Pin Elisa , Federici Giulia , Petricoin Emanuel F. 
Published: February 2014

AbstractReverse‐phase protein array (RPPA) is a multiplex, high‐throughput proteomic technique for profiling the activation status of signal transduction pathways involved in cancer survival and progression, potentially allowing for identification of new biomarkers and drug targets. On RPPA, the entire patient proteome is immobilized on a spot and single proteins can be quantified across a set of samples, spotted on the same array, with high specificity and sensitivity. Array immunostaining and signal amplification systems are used to generate a signal proportional to the concentration of the analyte. Dedicated scanners and software are used to detect spots, measure intensity, subtract background, normalize signal, and generate a numeric value as output. The generated output file is then analyzed using several different bioinformatic and biostatistical tools. In this unit, the RPPA procedure is described in depth, from sample handling and preparation to data analysis, with particular emphasis on tissue sample analysis. Curr. Protoc. Protein Sci. 75:27.7.1‐27.7.29. © 2014 by John Wiley & Sons, Inc.
Membrane Transport Piece by Piece: Production of Transmembrane Peptides for Structural and Functional Studies
Authors: Kemp Grant , Fliegel Larry , Young Howard S. 
Published: February 2014

AbstractMembrane proteins are involved in all cellular processes from signaling cascades to nutrient uptake and waste disposal. Because of these essential functions, many membrane proteins are recognized as important, yet elusive, clinical targets. Recent advances in structural biology have answered many questions about how membrane proteins function, yet one of the major bottlenecks remains the ability to obtain sufficient quantities of pure and homogeneous protein. This is particularly true for human membrane proteins, where novel expression strategies and structural techniques are needed to better characterize their function and therapeutic potential. One way to approach this challenge is to determine the structure of smaller pieces of membrane proteins that can be assembled into models of the complete protein. This unit describes the rationale for working with single or multiple transmembrane segments and provides a description of strategies and methods to express and purify them for structural and functional studies using a maltose binding protein (MBP) fusion. The bulk of the unit outlines a detailed methodology and justification for producing these peptides under native‐like conditions. Curr. Protoc. Protein Sci. 75:29.8.1‐29.8.28 © 2014 by John Wiley & Sons, Inc.
Ionospheric response to the ultrafast Kelvin wave in the MLT region
Authors: Gu Sheng‐Yang , Dou Xiankang , Lei Jiuhou , Li Tao , Luan Xiaoli , Wan Weixing , Russell J. M. 
Published: February 2014

AbstractThe modulation of the ultrafast Kelvin wave (UFKW) on the equatorial ionosphere is investigated, using satellite neutral wind and temperature observations in the mesosphere/lower thermosphere (MLT) and ground‐based global maps of total electron content (TEC) observations. The UFKW signatures are identified in the least squares fitting spectra for MLT zonal wind, temperature, TEC, and Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) electron density profiles, providing strong evidence for the neutral‐ion coupling through the UFKW. The periods of the UFKW are mostly confined within 2–5.5 days. The UFKW in zonal wind and temperature maximize in the equatorial regions, whereas the UFKW band‐pass perturbations in electron density peak at the equatorial ionization anomaly (EIA) crests with minima at the equator. The UFKW band‐pass perturbations in TEC show consistent seasonal variability with the UFKW in the MLT region, including the intraseasonal oscillations with periods of 20–70 days. The long‐term variability of the absolute UFKW band‐pass amplitudes in TEC is in‐phase with solar cycle with maximum amplitude of ~7–8 (~1–2) total electron content unit (TECU; 1 TECU = 1016 el m‐2) during solar maximum (minimum) years, while the relative amplitudes show little solar activity dependence. The COSMIC electron density profiles show that the UFKW band‐pass perturbations maximize at ~300–400 km with fountain‐like spatial distributions, indicating the modulation of the UFKW on the EIA through electrodynamics.
Groundwater and surface water flow to the Merced River, Yosemite Valley, California: 36Cl and Cl− evidence
Authors: Shaw Glenn D. , Conklin Martha H. , Nimz Gregory J. , Liu Fengjing 
Published: February 2014

AbstractOur current understanding of water fluxes and flow paths within the mountain block is limited, and improved understanding is necessary to assess hydrology more accurately above the mountain front. Source waters and the processes controlling their mixing were characterized in the Merced River basin within Yosemite National Park, California, using 36Cl and Cl−, supported by 222Rn, δ18O, δD, and streamflow data. Streams, snow, groundwater, and springs were sampled seasonally from July 2004 to October 2007. Three source water end‐members were identified: (i) near surface runoff of recent meltwater containing bomb‐pulse 36Cl (36ClBP), (ii) shallow, evapotranspired groundwater, and (iii) groundwater containing Cl− derived through extended rock interaction. Both groundwater end‐members mix in Yosemite Valley and then later discharge to the Merced River. Near surface runoff dominates all stream hydrographs during snowmelt, whereas the two groundwater end‐members become significantly more important during base flow. Tributaries consist of mixtures of the shallow evapotranspired groundwater and near surface runoff, whereas the Merced River is composed of the mixture of all source water end‐members. Snow is not an obvious end‐member, and elevated 36ClBP in the near surface runoff suggests that 36ClBP was retained efficiently, and is being slowly released as meltwater interacts with the soil. The use of 36Cl as a natural tracer is important in revealing the processes controlling streamflow generation in large montane catchments and the results will be helpful in configuring and calibrating hydrologic models.
Total Synthesis of (±)‐1‐Acetylaspidoalbidine and (±)‐1‐Methylaspidospermidine
Authors: Jin Jian , Qiu Fayang G. 
Published: February 2014

Abstract(±)‐1‐Acetylaspidoalbidine and (±)‐1‐methylaspidospermidine were synthesized from protected tryptamine through the combination of an organocatalytic Diels–Alder reaction, a tandem stereoselective ring‐opening reduction, and a double Michael addition.magnified image
Copper‐Catalyzed Aerobic Oxidative Annulation and Carbon‐Carbon Bond Cleavage of Arylacetamides: Domino Synthesis of Fused Quinazolinones
Authors: Sun Jie , Tan Qitao , Yang Wusong , Liu Bingxin , Xu Bin 
Published: February 2014

AbstractAn efficient copper‐catalyzed tandem aerobic oxidative annulation and carbon‐carbon bond cleavage reaction was developed from easily accessible arylacetamides, which provides a direct approach for the domino synthesis of a vast array of tricyclic or tetracyclic fused quinazolinone alkaloid structures. A plausible reaction mechanism is proposed involving an aerobic benzylic oxidation/cyclization/decarbonylation cascade.magnified image
Iron‐Catalysed Chemo‐, Regio‐, and Stereoselective Hydrosilylation of Alkenes and Alkynes using a Bench‐Stable Iron(II) Pre‐Catalyst
Authors: Greenhalgh Mark D. , Frank Dominik J. , Thomas Stephen P. 
Published: February 2014

AbstractThe chemo‐, regio‐, and stereoselective iron‐catalysed hydrosilylation of alkenes and alkynes with excellent functional group tolerance is reported (34 examples, 41–96% yield). The catalyst and reagents are commercially available and easy to handle, with the active iron catalyst being generated in situ, thus providing a simple and practical methodology for iron‐catalysed hydrosilylation. The silane products can be oxidised to the anti‐Markovnikov product of olefin hydration, and the one‐pot iron‐catalysed hydrosilylation–oxidation of olefins to give silane(di)ols directly is also reported. The iron pre‐catalyst was used at loadings as low as 0.07 mol%, and displayed catalyst turnover frequencies (TOF) approaching 60,000 mol h−1. Initial mechanistic studies indicate an iron(I) active catalyst.magnified image
Brønsted Acid‐Catalyzed Straightforward Synthesis of Benzo[b]carbazoles from 2,3‐Unsubstituted Indoles
Authors: Suárez Anisley , García‐García Patricia , Fernández‐Rodríguez Manuel A. , Sanz Roberto 
Published: February 2014

AbstractDescribed is a general and efficient synthesis of valuable benzo[b]carbazoles by Brønsted acid‐catalyzed reactions between simple C‐2,C‐3‐unsubstituted indoles and ortho‐[α‐(hydroxy)benzyl]benzaldehyde acetals. Highly selective migration processes are involved as key steps in the overall cascade sequence that involves the one‐pot formation of two new bonds and a cycle in a regioselective fashion.magnified image
Direct CH Arylations of Unactivated Arenes Catalyzed by Amido‐Functionalized Imidazolium Salts
Authors: Ghosh Debalina , Lee Jhen‐Yi , Liu Chian‐Yu , Chiang Yen‐Hsin , Lee Hon Man 
Published: February 2014

AbstractThe synthesis of biaryls from unactivated arenes and a broad range of aryl bromides and chlorides via the direct CH functionalization can be efficiently performed with the aid of amido‐functionalized imidazolium salts as organocatalysts. This method avoids the use of toxic transition metal catalysts and organometallic reagents.magnified image
A Coordination Compound of Ge0 Stabilized by a Diiminopyridine Ligand
Authors: Chu Terry , Belding Lee , van der Est Art , Dudding Travis , Korobkov Ilia , Nikonov Georgii I. 
Published: February 2014

AbstractReduction of the cationic GeII complex [dimpyrGeCl][GeCl3] (dimpyr=2,6‐(ArN=CMe)2NC5H3, Ar=2,6‐iPr2C6H3) with potassium graphite in benzene affords an air sensitive, dark green compound of Ge0, [dimpyrGe], which is stabilized by a bis(imino)pyridine platform. This compound is the first example of a complex of a zero‐valent Group 14 element that does not contain a carbene or carbenoid ligand. This species has a singlet ground state. DFT studies revealed partial delocalization of one of the Ge lone pairs over the π*(CN) orbitals of the imines. This delocalization results in a partial multiple‐bond character between the Ge atom and imine nitrogen atoms, a fact supported by the X‐ray crystallography and IR spectroscopy data.
α‐MsO/TsO/Cl‐Ketone als oxidierte Alkin‐Äquivalente: redoxneutrale Rhodium(III)‐katalysierte C‐H‐Aktivierung zur Synthese von N‐Heterocyclen
Authors: Yu Da‐Gang , de Azambuja Francisco , Glorius Frank 
Published: February 2014

Abstractα‐Halogenierte und pseudohalogenierte Ketone werden zum ersten Mal als sp3‐Kohlenstoff‐Elektrophile in der Übergangsmetall‐katalysierten C‐H‐Aktivierung sowie als oxidierte Alkin‐Äquivalente in der RhIII‐katalysierten redoxneutralen Anellierung zur Herstellung verschiedener N‐Heterocyclen eingesetzt. Die vorgestellte Methode ist effizient und skalierbar. Durch die milden Reaktionsbedindungen wird eine weite Zahl an funktionellen Gruppen toleriert.