bluuebunny/crossref_metadata_2025 huggingface dataset:
An RP-HPLC-UV Method with SPE for Cefotaxime in All-in-One Total Parenteral Nutritional Admixtures: Application to Stability Studies
Authors: Iqbal Muhammad Shahid , Bahari Mohd Baidi , Darwis Yusrida , Iqbal Muhammad Zahid , Hayat Amer , Gantala Venkatesh
Published: April 2013

A simple and selective RP-HPLC-UV method with SPE was developed and validated for the quantification of cefotaxime in all-in-one total parenteral nutrition (AIO-TPN) admixtures. Chromatographic separation was achieved on a 5 μm particle size C18 DB column (250 × 4.6 mm id) using the mobile phase ammonium acetate (25 mM, pH 4.0)–50% acetonitrile in methanol (80 + 20, v/v). The flow rate was 0.9 mL/min and the detection wavelength was 254 nm. The analyte was extracted from AIO-TPN admixtures by means of an SPE method. The cefotaxime calibration curve was linear over a concentration range of 100–1400 μg/mL with a correlation coefficient of ≥0.9994. The intraday accuracy and precision for cefotaxime were ≤–3.15 and ≤3.08%, respectively, whereas the interday accuracy and precision were ≤–2.48 and ≤2.25%, respectively. The method was successfully applied to stability studies of cefotaxime in the presence of micronutrients together with low and high concentrations of macronutrients in AIO-TPN admixtures. Cefotaxime was degraded by 13.00 and 26.05% at room temperature (25 ± 2°C) after 72 h in low and high macronutrient concentration formulations of AIO-TPN admixtures, respectively. The values of cefotaxime degradation rates for low and high macronutrient concentration formulations of AIO-TPN admixtures were –0.164 and –0.353, respectively. These results indicated that there was higher rate of degradation in the AIO-TPN admixture formulations containing high concentrations of macronutrients.
Validated Stability-Indicating Methods for the Simultaneous Determination of Amiloride Hydrochloride, Atenolol, and Chlorthalidone Using HPTLC and HPLC with Photodiode Array Detector
Authors: Youssef Rasha M , Maher Hadir M , El-Kimary Eman I , Hassan Ekram M , Barary Magda H
Published: April 2013

Two stability-indicating chromatographic methods are described for simultaneous determination of amiloride hydrochloride (AMI), atenolol (ATE), and chlorthalidone (CHL) in combined dosage forms. The first method was based on HPTLC separation of the three drugs followed by densitometric measurements of their bands at 274 nm. The separation was carried out on Merck HPTLC silica gel 60F254 aluminum sheets using chloroform–methanol–ammonia 27%, w/w (9 + 2 + 0.3, v/v/v) mobile phase. Analysis data was used for the linear regression graph in the range of 0.1–0.5, 0.8–5.0, and 0.3–1.5 μg/band for AMI, ATE, and CHL, respectively. The second method was based on an RP-HPLC separation of the cited drugs performed on an RP stainless steel C18 analytical column (250 × 4.6 mm id) with a gradient elution system of methanol and 0.05 M aqueous phosphate buffer adjusted to pH 4 as the mobile phase, at the flow rate of 1.0 mL/min. Quantitation was achieved with photodiode array detection at 275 nm for AMI and 225 nm for ATE and CHL. The calibration graphs for each drug were rectilinear in the range of 2–50, 25–150, and 2–100 μg/mL for AMI, ATE, and CHL, respectively. The proposed chromatographic methods were successfully applied for determination of the investigated drugs in pharmaceutical preparations. Both methods were validated in compliance with International Conference on Harmonization guidelines in terms of linearity, accuracy, precision, robustness, LOD, and LOQ.
Montréal, foyer de la vie culturelle au Canada français durant la première moitié du XXe siècle. Domination et résistance
Authors: Saint-Jacques Denis
Published: April 2013

L’article veut poser quelques balises autour de la question de l’évolution de « la vie culturelle à Montréal durant la première moitié du xxe siècle ». Il cherche à en problématiser trois éléments fondamentaux : premièrement, l’objet lui-même, deuxièmement, l’espace en cause et, troisièmement, la périodisation. Dans le premier cas se pose la question du sens à donner à « vie culturelle » et de l’étendue des pratiques que nous y avons reconnues comme un même ensemble. Dans le deuxième, il s’agit de comprendre par quelles voies complexes un nouveau foyer, urbain, Montréal, s’affirme comme pôle culturel homogénéisateur au Canada français au détriment de pratiques antérieures dispersées sur un territoire plus large. Dans le troisième, la visée concerne l’explicitation des limites temporelles qui peuvent servir à circonscrire ce mouvement et, en particulier, à comprendre pourquoi des tendances reconnues dès la fin du xixe siècle n’arrivent vraiment à réalisation qu’un demi-siècle plus tard, durant les années 1940.
Enjeux de la constitution et de l’exploitation de bases de données en sociologie de l’art et de la culture
Authors: Dozo Björn-Olav , Lapointe Olivier
Published: April 2013

Cet article présente certains enjeux spécifiques à la mobilisation de bases de données dans des projets de recherche en sociologie de l’art et de la culture. À partir de trois exemples concrets en histoire du livre (« Base de données des métiers du livre au Québec »), en sociologie de l’art (« Base des prix artistiques au Québec dans l’entre-deux-guerres ») et en études littéraires (« Base de données sur les figurations romanesques de la vie littéraire au xixe et xxe siècles »), il décrit les questions soulevées par ces usages particuliers de bases de données et les exploitations potentielles qu’elles permettent. Il offre aussi une réflexion générale sur la constitution et la normalisation de bases de données dans ces domaines.
Une étape méconnue de l’humour graphique : les bandes dessinées de La Presse et de La Patrie, 1904-1910. Perspectives de recherche pour l’histoire de l’art1
Authors: Danaux Stéphanie
Published: April 2013

De 1904 à 1910, la bande dessinée humoristique connaît une brève période d’essor puis de déclin dans les suppléments du samedi des journaux La Patrie et La Presse. Cet article propose quelques pistes de recherche susceptibles d’offrir une meilleure connaissance de cette période fertile, mais méconnue, de l’histoire des arts graphiques et de l’humour visuel au Québec, notamment la question de la production des pionniers du genre et des liens noués avec d’autres formes graphiques, celle des sujets traités, avec l’apparition du thème du garnement, et, enfin, celle de sa réception.
Management of Incidental Findings in Clinical Genomic Sequencing
Authors: Krier Joel B. , Green Robert C.
Published: April 2013

Genomic sequencing is becoming accurate, fast, and inexpensive, and is rapidly being incorporated into clinical practice. Incidental findings, which result in large numbers from genomic sequencing, are a potential barrier to the utility of this new technology due to their high prevalence and the lack of evidence or guidelines available to guide their clinical interpretation. This unit reviews the definition, classification, and management of incidental findings from genomic sequencing. The unit focuses on the clinical aspects of handling incidental findings, with an emphasis on the key role of clinical context in defining incidental findings and determining their clinical relevance and utility. Curr. Protoc. Hum. Genet. 77:9.23.1‐9.23.13. © 2013 by John Wiley & Sons, Inc.
Probing Bias‐Dependent Electrochemical Gas–Solid Reactions in (LaxSr1–x)CoO3–δ Cathode Materials
Authors: Kumar Amit , Ciucci Francesco , Leonard Donovan , Jesse Stephen , Biegalski Mike , Christen Hans , Mutoro Eva , Crumlin Ethan , Shao‐Horn Yang , Borisevich Albina , Kalinin Sergei V.
Published: April 2013

Spatial variability of bias‐dependent electrochemical processes on a (La0.5Sr0.5)2CoO4±δ modified (LaxSr1–x)CoO3–δ surface is studied using first‐order reversal curve method in electrochemical strain microscopy (ESM). The oxygen reduction/evolution reaction (ORR/OER) is activated at voltages as low as 3–4 V with respect to bottom electrode. The degree of bias‐induced transformation as quantified by ESM hysteresis loop area increases with applied bias. The variability of electrochemical activity is explored using correlation analysis and the ORR/OER is shown to be activated in grains at relatively low biases, but the final reaction rate is relatively small. At the same time, at grain boundaries, the onset of reaction process corresponds to larger voltages, but limiting reactivity is much higher. The reaction mechanism in ESM of mixed electronic‐ionic conductor is further analyzed. These studies both establish the framework for probing bias‐dependent electrochemical processes in solids and demonstrate rich spectrum of electrochemical transformations underpinning catalytic activity in cobaltites.
Thermal conductivity of anisotropic, inhomogeneous high‐density foam calculated from three‐dimensional reconstruction of microtome images
Authors: Hegdal Jan Peder , Tofteberg Terje Rosquist , Schjelderup Trond , Hinrichsen Einar Louis , Grytten Frode , Echtermeyer Andreas
Published: April 2013

An effective method is developed to predict the thermal conductivity of thick foam insulation on offshore oil and gas pipelines. High‐resolution three‐dimensional (3D) images (212 megavoxels) spanning macroscopic sample volumes (38 × 19 × 4 mm3) are obtained and used to create a 3D geometry of the foam. A gravimetric technique is developed to measure the mass density through the foam thickness and used to verify the 3D geometry. The local anisotropic thermal conductivity through the thickness of the foam is calculated using the finite element method on the 3D geometry and the results are verified against measurements and found to be in good agreement. Results show that thermal conductivity is dependent on morphology. For the highly anisotropic part of the foam where the long axes of the bubbles are oriented parallel to the axial direction of the pipe, the radial thermal conductivity is lowered significantly compared to more isotropic foam. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1020‐1028, 2013
Optimization of the conductivity and yield of chemically synthesized polyaniline using a design of experiments
Authors: Jelmy E. Johny , Ramakrishnan S. , Devanathan Sriram , Rangarajan Murali , Kothurkar Nikhil K.
Published: April 2013

The electrical conductivity and yield of polyaniline (PANi) were optimized using a design of experiments (DOE). PANi samples were synthesized by the chemical oxidative polymerization of aniline using methane sulfonic acid as the dopant acid and ammonium persulfate as the oxidant. The main factors in the synthesis of PANi that can affect the conductivity were identified as (i) the concentration of dopant acid, (ii) oxidant‐to‐monomer ratio, and (iii) the addition rate of oxidant to monomer. Using a Box‐Behnken DOE method the regression equation, main effects plots, contour plots, and optimization plots for conductivity and yield were generated and analyzed. Under the optimized conditions of dopant acid concentration of 0.9M, an oxidant addition rate of 30 mL/h and an OM ratio of 0.9, PANi with a conductivity of 1.95 S/cm and yield of 95% was obtained. The observed trends in the four‐point probe conductivity measurements were correlated with the polymer structure using fourier transform infrared spectroscopy, X‐ray diffraction studies, and scanning electron microscopy. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1047‐1057, 2013
Behavioral changes in transmuting multisession successive searches over the web
Authors: Lin Shinjeng , Xie Iris
Published: April 2013

Multisession successive information searches are common but little research has focused on quantitative analysis. This article enhances our understanding of successive information searches by employing an experimental method to observe whether and how the behavioral characteristics of searchers statistically significantly changed over sessions. It focuses on a specific type of successive search called transmuting successive searches, in which searchers learn about and gradually refine their information problems during the course of the information search. The results show that searchers' behavioral characteristics indeed exhibit different patterns in different sessions. The identification of the behavioral characteristics can help information retrieval systems to detect stages or sessions of the information search process. The findings also help validate a theoretical framework to explain successive searches and suggest system requirements for supporting the associated search behavior. The study is one of the first to not only test for statistical significance among research propositions concerning successive searches but to also apply the research principles of implicit relevance feedback to successive searches.
Assessment of recurrence and complications following uncomplicated diverticulitis
Authors: Buchs N C , Konrad-Mugnier B , Jannot A-S , Poletti P-A , Ambrosetti P , Gervaz P
Published: April 2013

Background

The natural history of sigmoid diverticulitis has been inferred from population-based or retrospective studies. This study assessed the risk of a recurrent attack following the first episode of uncomplicated diverticulitis.

Methods

Patients admitted between January 2007 and December 2011 with a first episode of uncomplicated sigmoid diverticulitis confirmed on computed tomography were enrolled in this prospective study. After successful medical management of the first episode, follow-up was conducted through yearly telephone interviews. Cox proportional hazards regression was performed to model the impact of various parameters on eventual recurrences and complications.

Results

During a median follow-up of 24 (range 3–63) months, 46 (16·4 per cent) of 280 patients experienced a second episode of diverticulitis. Six patients (2·1 per cent) subsequently developed complicated diverticulitis and four (1·4 per cent) underwent emergency surgery for peritonitis. In multivariable analysis, a raised serum level of C-reactive protein (over 240 mg/l) during the first attack was associated with early recurrence (hazard ratio 1·75, 95 per cent confidence interval 1·04 to 2·94; P = 0·035).

Conclusion

Uncomplicated sigmoid diverticulitis follows a benign course with few recurrences and little need for emergency surgery. Registration number: NCT01015378 (http://www.clinicaltrials.gov).
Internationalization and Faculty‐Led Service Learning
Authors: Bradshaw Geoffrey W.
Published: April 2013

This chapter examines faculty‐led study‐abroad programs as a strategy for increasing the breadth and depth of internationalization in community college education and uses the case study of Madison Area Technical College to examine the role of comprehensive internationalization in community college education.
U.S. Community Colleges and a Response to the Arab Spring
Authors: Shumaker John W.
Published: April 2013

The tumultuous events of the Arab Spring have challenged higher education systems throughout the Middle East and North Africa to become more responsive to citizens who are impatient for change. Community colleges in the United States can play a vital role in supporting much‐needed reforms. This article looks at the possibilities and the challenges that community colleges in the United States must anticipate as they develop new partnerships in the region.
Autocatalytic Intermolecular versus Intramolecular Deprotonation in CH Bond Activation of Functionalized Arenes by Ruthenium(II) or Palladium(II) Complexes
Authors: Fabre Indira , von Wolff Niklas , Le Duc Gaëtan , Ferrer Flegeau Emmanuel , Bruneau Christian , Dixneuf Pierre H. , Jutand Anny
Published: April 2013

The activation of the CH bond of 1‐phenylpyrazole (2) and 2‐phenyl‐2‐oxazoline (3) by [Ru(OAc)2(p‐cymene)] is an autocatalytic process catalyzed by the co‐product HOAc. The reactions are indeed faster in the presence of acetic acid and water but slower in the presence of a base K2CO3. A reactivity order is established in the absence of additives: 2‐phenylpyridine>2‐phenyl‐2‐oxazoline>1‐phenylpyrazole (at RT). The accelerating effect of added acetate ions reveals an intermolecular deprotonation after CH bond activation by a cationic RuII center (SE3 mechanism). The reactions of 1‐phenylpyrazole and 2‐phenyl‐2‐oxazoline first lead to the neutral cyclometalated complexes A2 and A3 ligated by one acetate. The latter dissociate to the cationic complexes B2+ and B3+, respectively, and acetate. A slow incorporation of one or two D atoms into 2, 3, and 2‐phenylpyridine (1) was observed in the presence of deuterated acetic acid. The “reversibility” of the CH bond activation/deprotonation takes place from the cationic complexes Bn+ (n=1–3). They are also involved in oxidative additions to PhI, which are rate‐determining and lead to the mono‐ and bis‐phenylated products at high temperatures. A general mechanism is proposed for the arylation of arenes 1–3 catalyzed by [Ru(OAc)2(p‐cymene)]. In contrast, the reaction of Pd(OAc)2 with 2‐phenylpyridine (1), is much faster: Pd(OAc)2>[Ru(OAc)2(p‐cymene)]. Since the kinetics is not affected by added acetates, the reaction proceeds through a CMD mechanism assisted by a ligated acetate (intramolecular process) and is irreversible. A bis‐cyclometalated PdII^PdII dimer D′1 is formed whose bielectronic electrochemical oxidation leads to a [PdIII^PdIII]2+ dimer, in agreement with the result of a reported chemical oxidation used in arene functionalizations catalyzed by Pd(OAc)2.
Targeting the Substrate Binding Site of E. coli Nitrile Reductase QueF by Modeling, Substrate and Enzyme Engineering
Authors: Wilding Birgit , Winkler Margit , Petschacher Barbara , Kratzer Regina , Egger Sigrid , Steinkellner Georg , Lyskowski Andrzej , Nidetzky Bernd , Gruber Karl , Klempier Norbert
Published: April 2013

Nitrile reductase QueF catalyzes the reduction of 2‐amino‐5‐cyanopyrrolo[2,3‐d]pyrimidin‐4‐one (preQ0) to 2‐amino‐5‐aminomethylpyrrolo[2,3‐d]pyrimidin‐4‐one (preQ1) in the biosynthetic pathway of the hypermodified nucleoside queuosine. It is the only enzyme known to catalyze a reduction of a nitrile to its corresponding primary amine and could therefore expand the toolbox of biocatalytic reactions of nitriles. To evaluate this new oxidoreductase for application in biocatalytic reactions, investigation of its substrate scope is prerequisite. We report here an investigation of the active site binding properties and the substrate scope of nitrile reductase QueF from Escherichia coli. Screenings with simple nitrile structures revealed high substrate specificity. Consequently, binding interactions of the substrate to the active site were identified based on a new homology model of E. coli QueF and modeled complex structures of the natural and non‐natural substrates. Various structural analogues of the natural substrate preQ0 were synthesized and screened with wild‐type QueF from E. coli and several active site mutants. Two amino acid residues Cys190 and Asp197 were shown to play an essential role in the catalytic mechanism. Three non‐natural substrates were identified and compared to the natural substrate regarding their specific activities by using wild‐type and mutant nitrile reductase.
Chemisorption of Exchange‐Coupled [Ni2L(dppba)]+ Complexes on Gold by Using Ambidentate 4‐(Diphenylphosphino)benzoate Co‐Ligands
Authors: Golecki Matthias , Lach Jochen , Jeremies Alexander , Lungwitz Frank , Fronk Michael , Salvan Georgeta , Zahn Dietrich R. T. , Park Jaena , Krupskaya Yulia , Kataev Vladislav , Klingeler Rüdiger , Büchner Bernd , Mahns Benjamin , Knupfer Martin , Siles Pablo F. , Grimm Daniel , Schmidt Oliver G. , Reis Andreas , Thiel Werner R. , Breite Daniel , Abel Bernd , Kersting Berthold
Published: April 2013

A new strategy for the fixation of redox‐active dinickel(II) complexes with high‐spin ground states to gold surfaces was developed. The dinickel(II) complex [Ni2L(Cl)]ClO4 (1ClO4), in which L2− represents a 24‐membered macrocyclic hexaaza‐dithiophenolate ligand, reacts with ambidentate 4‐(diphenylphosphino)benzoate (dppba) to form the carboxylato‐bridged complex [Ni2L(dppba)]+, which can be isolated as an air‐stable perchlorate [Ni2L(dppba)]ClO4 (2ClO4) or tetraphenylborate [Ni2L(dppba)]BPh4 (2BPh4) salt. The auration of 2ClO4 was probed on a molecular level, by reaction with AuCl, which leads to the monoaurated NiII2AuI complex [NiII2L(dppba)AuICl]ClO4 (3ClO4). Metathesis of 3ClO4 with NaBPh4 produces [NiII2L(dppba)AuIPh]BPh4 (4BPh4), in which the Cl− is replaced by a Ph− group. The complexes were fully characterized by ESI mass spectrometry, IR and UV/Vis spectroscopy, X‐ray crystallography (2BPh4 and 4BPh4), cyclic voltammetry, SQUID magnetometry and HF‐ESR spectroscopy. Temperature‐dependent magnetic susceptibility measurements reveal a ferromagnetic coupling J=+15.9 and +17.9 cm−1 between the two NiII ions in 2ClO4 and 4BPh4 (H=−2 JS1S2). HF‐ESR measurements yield a negative axial magnetic anisotropy (D<0), which implies a bistable (easy axis) magnetic ground state. The binding of the [Ni2L(dppba)]ClO4 complex to gold was ascertained by four complementary surface analytical methods: contact angle measurements, atomic‐force microscopy, X‐ray photoelectron spectroscopy, and spectroscopic ellipsometry. The results indicate that the complexes are attached to the Au surface through coordinative AuP bonds in a monolayer.
Determination of pH Value in Biotechnology
Authors: Henkel Steffen , Beutel Sascha
Published: April 2013

Die gängigsten Messmethoden zur Bestimmung des pH‐Werts sind elektrochemischer oder optischer Natur. Als Messsysteme sind dabei besonders die Glaselektrode oder aber der pH‐Teststreifen jedem Anwender geläufig. Daneben existieren aber auch weitere Messprinzipien für speziellere Anwendungen z. B. zur pH‐Bestimmung in Geweben, Pasten oder unter extremen Prozessbedingungen. Zudem gibt es Methoden wie die pH‐Messung mithilfe der NMR, die allein aufgrund des apparativen Aufwands über ein Nischendasein nicht herauskommen werden. Die verschiedenen Methoden zur pH‐Bestimmung werden vorgestellt und ihre Vor‐ und Nachteile diskutiert.
XpressSpace: a programming framework for coupling partitioned global address space simulation codes
Authors: Zhang Fan , Docan Ciprian , Bui Hoang , Parashar Manish , Klasky Scott
Published: April 2013

Complex coupled multiphysics simulations are playing increasingly important roles in scientific and engineering applications such as fusion, combustion, and climate modeling. At the same time, extreme scales, increased levels of concurrency, and the advent of multicores are making programming of high‐end parallel computing systems on which these simulations run challenging. Although partitioned global address space (PGAS) languages attempt to address the problem by providing a shared memory abstraction for parallel processes within a single program, the PGAS model does not easily support data coupling across multiple heterogeneous programs, which is necessary for coupled multiphysics simulations. This paper explores how multiphysics‐coupled simulations can be supported by the PGAS programming model. Specifically, in this paper, we present the design and implementation of the XpressSpace programming system, which extends existing PGAS data sharing and data access models with a semantically specialized shared data space abstraction to enable data coupling across multiple independent PGAS executables. XpressSpace supports a global‐view style programming interface that is consistent with the PGAS memory model, and provides an efficient runtime system that can dynamically capture the data decomposition of global‐view data‐structures such as arrays, and enable fast exchange of these distributed data‐structures between coupled applications. In this paper, we also evaluate the performance and scalability of a prototype implementation of XpressSpace by using different coupling patterns extracted from real world multiphysics simulation scenarios, on the Jaguar Cray XT5 system at Oak Ridge National Laboratory. Copyright © 2013 John Wiley & Sons, Ltd.
A fundamental study of spectrum center estimation of solar spectral irradiation by statistical pattern recognition
Authors: Iijima Aya , Suzuki Kazumi , Wakao Shinji , Kawasaki Norihiro , Usami Akira
Published: April 2013

Against a background of environmental problems and energy issues, it is expected that PV systems will be introduced rapidly and connected with power grids on a large scale in the future. For this reason, concerns about how PV power generation will aﬀect supply and demand adjustment in electric power in the future arise, and the technique of correctly grasping PV power generation becomes increasingly important. PV power generation depends on solar irradiance, module temperature, and solar spectral irradiance. Solar spectral irradiance is the distribution of the light intensity for every wavelength. As the spectral sensitivity of solar cells depends on the kind of solar cell, it becomes important for an exact grasp of PV power generation. But the preparation of solar spectral irradiance data is not easy because observational instruments for solar spectral irradiance are expensive. Against this background, in this paper, we propose a new method based on statistical pattern recognition for estimating the spectrum center, which is a representative index of solar spectral irradiance. Some numerical examples obtained by the proposed method are also presented. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 184(1): 10–18, 2013; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22393
Synthesis of Dibromobenzobarrelene Derivatives and Catalytic Activity of Their Rhodium Complexes
Authors: Schlesinger Maik , Hofmann Max , Rüffer Tobias , Schaarschmidt Dieter , Lang Heinrich , Theilacker Sergio , Schürmann Markus , Jurkschat Klaus , Mehring Michael
Published: April 2013

A novel synthetic route based on [4+2] cycloaddition for dibromobenzobarrelene derivatives starting from in situ generated 3,5‐dibromo‐1,2‐didehydrobenzene and mesitylene, 1,2,4,5‐tetramethylbenzene, 1,2,3,5‐tetramethylbenzene, pentamethylbenzene, 1,3‐dimethoxybenzene, and 2,4,6‐trimethylbromobenzene, respectively, was developed. Thus, six novel dibromobenzobarrelenes with diverse substitution patterns at the barrelene framework including chiral derivatives are reported. The benzobarrelene 6,8‐dibromo‐1,3,10‐trimethyl‐1,4‐dihydro‐1,4‐ethenonaphthalene (1a) was functionalized at the annulated benzene ring to give three novel carboxylic acids and two novel phosphonic acid esters. Selected benzobarrelene complexes with RhICl were tested for their catalytic activity in the 1,4‐addition of phenylboronic acid towards cyclohex‐2‐enone. Turnover frequencies up to 3405 h–1 were observed, which are among the highest reported so far for Rh–diene complexes in this type of C–C coupling reaction.
Divergent Reactivity of TEMPO with MBr3 (M = B, Al)
Authors: Wright Ashley M. , Page Joshua S. , Scepaniak Jeremiah J. , Wu Guang , Hayton Trevor W.
Published: April 2013

Addition of TEMPO (TEMPO = 2,2,6,6‐tetramethylpiperidine‐N‐oxyl) to a toluene slurry of AlBr3 results in rapid formation of AlBr3(η1‐TEMPO) (1), which can be isolated in 65 % yield. In contrast, addition of TEMPO to a hexanes solution of BBr3 results in formation of [TEMPO][BBr4] (2) and (TEMPO)2BBr (3), the products of TEMPO disproportionation. Complexes 1–3 have been fully characterized, including analysis by X‐ray crystallography. The divergent reactivity is likely dictated by the Lewis acidity of the group 13 halide, and in the case of the stronger Lewis acid BBr3, coordination of TEMPO to the boron center generates an adduct that is capable of oxidizing free TEMPO.
A Synthetic Cycle for Nitrogen Atom Transfer Featuring a Diruthenium Nitride Intermediate
Authors: Corcos Amanda R. , Long Amanda Kae Musch , Guzei Ilia A. , Berry John F.
Published: April 2013

A new Ru2 azido complex, [Ru2(chp)4N3] (4, chp = 2‐chloro‐6‐hydroxypyridinate), was investigated under photolytic conditions to study the chemical reactivity of the corresponding Ru2 nitride species, [Ru2(chp)4N] (6), towards intermolecular N atom transfer to triphenylphosphane (PPh3). Photolysis of a dichloromethane solution of 4 at λ > 350 nm leads to a characteristic color change from purple to magenta. Upon acidic workup, triphenylphosphanamine chloride ([H2NPPh3]Cl) is produced and [Ru2(chp)4Cl] (5), the precursor to 4, is regenerated. The first stoichiometric cycle for intermolecular N atom transfer from a Ru2 nitride is thus presented.
Uptake and depuration of pharmaceuticals in reclaimed water by mosquito fish (Gambusia holbrooki): A worst-case, multiple-exposure scenario
Authors: Wang Jian , Gardinali Piero R.
Published: April 2013

Previous studies showed that caffeine, diphenhydramine, and carbamazepine were bioconcentrated by mosquito fish (Gambusia holbrooki) from freshwater bodies directly affected by reclaimed water. To understand the uptake, depuration, and bioconcentration factors (BCFs) under the worst-case conditions, the authors exposed 84 mosquito fish to reclaimed water under static renewal for 7 d, followed by a 14-d depuration phase in clean water. Characterization of the exposure media revealed the presence of 26 pharmaceuticals, whereas only 5 pharmaceuticals—caffeine, diphenhydramine, diltiazem, carbamazepine, and ibuprofen—were present in the organisms after only 5 h of exposure. Caffeine, diltiazem, and carbamazepine were quickly taken up by mosquito fish following a similar uptake curve. Diphenhydramine and ibuprofen, on the other hand, were more gradually taken up by mosquito fish but were also eliminated fairly quickly, resulting in the 2 shortest depuration half-lives at 34 h and 32 h, respectively. For comparison, BCFs based on rate constants (BCFb), steady-state concentrations (BCFa), and saturation-state concentrations (BCFc) were calculated. Values of BCFb ranged from 0.23 to 29 and increased in the order of caffeine < carbamazepine < diltiazem < diphenhydramine < ibuprofen. Values of BCFa and BCFc ranged from 2.0 to 28 and increased in the order of carbamazepine < caffeine < diltiazem < diphenhydramine < ibuprofen. This is the first study using a nonartificial exposure–treated wastewater matrix to generate pharmacokinetic data for pharmaceutical mixtures in aquatic organisms. Environ Toxicol Chem 2013;32:1752–1758. © 2013 SETAC
Genetic Association Analysis and Meta‐Analysis of Imputed SNPs in Longitudinal Studies
Authors: Subirana Isaac , González Juan R
Published: April 2013

In this paper we propose a new method to analyze time‐to‐event data in longitudinal genetic studies. This method address the fundamental problem of incorporating uncertainty when analyzing survival data and imputed single‐nucleotide polymorphisms (SNPs) from genome‐wide association studies (GWAS). Our method incorporates uncertainty in the likelihood function, the opposite of existing methods that incorporate the uncertainty in the design matrix. Through simulation studies and real data analyses, we show that our proposed method is unbiased and provides powerful results. We also show how combining results from different GWAS (meta‐analysis) may lead to wrong results when effects are not estimated using our approach. The model is implemented in an R package that is designed to analyze uncertainty not only arising from imputed SNPs, but also from copy number variants.
Doxycycline restrains glia and confers neuroprotection in a 6‐OHDA Parkinson model
Authors: Lazzarini Marcio , Martin Sabine , Mitkovski Mišo , Vozari Rita Raisman , Stühmer Walter , Bel Elaine Del
Published: April 2013

Neuron–glia interactions play a key role in maintaining and regulating the central nervous system. Glial cells are implicated in the function of dopamine neurons and regulate their survival and resistance to injury. Parkinson's disease is characterized by the loss of dopamine neurons in the substantia nigra pars compacta, decreased striatal dopamine levels and consequent onset of extrapyramidal motor dysfunction. Parkinson's disease is a common chronic, neurodegenerative disorder with no effective protective treatment. In the 6‐OHDA mouse model of Parkinson's disease, doxycycline administered at a dose that both induces/represses conditional transgene expression in the tetracycline system, mitigates the loss of dopaminergic neurons in the substantia nigra compacta and nerve terminals in the striatum. This protective effect was associated with: (1) a reduction of microglia in normal mice as a result of doxycycline administration per se; (2) a decrease in the astrocyte and microglia response to the neurotoxin 6‐OHDA in the globus pallidus and substantia nigra compacta, and (3) the astrocyte reaction in the striatum. Our results suggest that doxycycline blocks 6‐OHDA neurotoxicity in vivo by inhibiting microglial and astrocyte expression. This action of doxycycline in nigrostriatal dopaminergic neuron protection is consistent with a role of glial cells in Parkinson's disease neurodegeneration. The neuroprotective effect of doxycycline may be useful in preventing or slowing the progression of Parkinson's disease and other neurodegenerative diseases linked to glia function.
Langmuir “snakes” and electrostatic decay in the solar wind
Authors: Graham D. B. , Cairns Iver H. , Robinson P. A.
Published: April 2013

When Langmuir waves are driven by an electron beam to large amplitudes, they can undergo electrostatic (ES) decay to smaller wave numbers via a series of backscatters. Truncated ES decay, where the number of backscatters is reduced due to damping, is modeled here using the three‐dimensional ES Zakharov equations. Langmuir beats develop in “snake”‐like structures parallel to the electron beam direction and are most evident when decay is truncated to a single backscatter. From these results, an analytic form is derived and shown to be consistent with some of the waveforms and spectra observed by STEREO in the source regions of type III solar radio bursts. The agreement between the model and observations provides strong evidence for ES decay and Langmuir “snakes” parallel to the electron beam and so the ambient magnetic field.
Parallel imaging improves the image quality and duct visibility of breathhold two‐dimensional thick‐slab MR cholangiopancreatography
Authors: Lee Ju Hee , Lee Seung Soo , Kim Joo Young , Kim In Seong , Byun Jae Ho , Park Seong Ho , Lee Moon‐Gyu
Published: April 2013

Purpose

To evaluate the effect of parallel imaging (PI) with different acceleration factors on the image quality and duct visibility of breathhold two‐dimensional (2D) thick‐slab single‐shot turbo spin‐echo (SSTSE) MR cholangiopancreatography (MRCP) images.

Materials and Methods

Breathhold 2D thick‐slab SSTSE MRCP was performed three times, i.e., without PI, with PI factor 2, and with PI factor 3, at 1.5 Tesla (T) for each of 85 patients. Two, independent readers evaluated the image quality and the visibility of five duct segments and ranked their preference of the three MRCP sequences. The data were analyzed using the repeated‐measures analysis of variance test, the Friedman test, and the linear‐by‐linear chi‐square test.

Results

MRCP sequences with PI factor 2 or 3 generated better image quality (P < 0.001) and an improved duct visibility for all duct segments (P ≤ 0.01), while no significant difference was noted between the MRCP sequences with PI factor 2 and PI factor 3 (P > 0.05). Among the three sequences, both readers most often preferred the MRCP with PI factor 3, followed by the MRCP with PI factor 2 (P < 0.001).

Conclusion

The application of PI improves the image quality and duct visibility in breathhold 2D thick‐slab SSTSE MRCP. J. Magn. Reson. Imaging 2014;39:269–275. © 2013 Wiley Periodicals, Inc.
Expression of matrix metalloproteinases and their inhibitors in the woodchuck model of hepatocellular carcinoma
Authors: Ochoa‐Callejero Laura , Toshkov Ilia , Menne Stephan , Martínez Alfredo
Published: April 2013

Matrix metalloproteinases (MMPs) play a central role in tumor invasion and metastasis. Increased expression of MMPs occurs during development of hepatocellular carcinoma (HCC) in humans following infection with hepatitis B virus (HBV). Woodchucks are used as an animal model for hepadnavirus‐induced HCC. All woodchucks infected chronically with woodchuck hepatitis virus (WHV), a virus that is closely related to HBV, develop HCC. In the present study MMPs and related molecules were investigated in woodchucks to better understand the mechanisms of extracellular matrix remodeling in HCC. Three groups of samples were studied: liver and HCC tissues from animals infected with WHV and age‐ and gender‐matched normal liver from animals not infected with WHV. New partial gene sequences for woodchuck MMP‐2, MMP‐7, and MMP‐9 as well as their inhibitors NGAL, TIMP‐1, and TIMP‐2 were identified and used for determination of expression levels in liver and HCC by qRT‐PCR. Compared to liver of WHV‐naïve woodchucks, high levels of MMP‐1, MMP‐2, MMP‐7, NGAL, and TIMP‐1 were detected in liver of animals infected with WHV. However, no differences were found for TIMP‐2. MMP‐9 expression was higher in HCC than in liver of animals not infected with WHV. Immunohistochemical staining demonstrated that MMP‐9 immunoreactivity was most intense in HCC, correlating with the progression of liver disease. Upregulation of MMP‐9 in HCC was confirmed by Western blotting and zymography analysis. Furthermore, the activity of woodchuck MMPs was suppressed by BiPS, a common inhibitor of mammalian MMPs. These results suggest the use of MMP inhibitors as a potential HCC treatment strategy that could be explored in woodchucks. J. Med. Virol. 85:1127–1138, 2013. © 2013 Wiley Periodicals, Inc.
Meta‐analysis inside and outside particle physics: convergence using the path of least resistance?
Authors: Jackson Dan , Baker Rose
Published: April 2013

In this note, we explain how the method proposed by Hartung and Knapp provides a compromise between conventional meta‐analysis methodology and ‘unconstrained averaging’, as used by the Particle Data Group. Copyright © 2013 John Wiley & Sons, Ltd.
Use of chlorine dioxide gas for the postharvest control of Alternaria alternata and Stemphylium vesicarium on Roma tomatoes
Authors: Trinetta Valentina , Linton Richard H , Morgan Mark T
Published: April 2013

BACKGROUND

Tomatoes and potatoes are the top produce affected in terms of value lost in the USA. Postharvest losses can occur anywhere from the time of harvest to the consumers' decision to eat or discard the food. These data support the importance of finding sustainable strategies to minimise food waste and preserve resources. This study evaluated the potential application of chlorine dioxide gas (ClO2) technology to control the postharvest spoilage of Roma tomatoes by Alternaria alternata and Stemphylium vesicarium.

RESULTS

Data analysis showed that exposure time was a significant factor for fungal disease control (P < 0.05). After 3 min of treatment, mycelial growth was completely inhibited for A. alternata and S. vesicarium. Similar results were observed for conidial germination. The efficacy of ClO2 treatments was also studied under in vivo conditions. While untreated Roma tomatoes developed white moulds and black spots after 5 days of storage, produce decay was significantly (P < 0.05) delayed after 5 and 7 min treatments for S. vesicarium and A. alternata respectively.

CONCLUSION

The use of ClO2 in the food industry is regulated by both the FDA and the EPA. Currently, only acidified sodium chlorite solutions are approved for the control of micro‐organisms in water used to wash fruits and vegetables. No direct applications of ClO2 gas on fresh fruits and vegetables can be found in the regulations. More data are required by the two agencies to demonstrate that residues of ClO2 on produce surfaces are acceptable for human consumption. © 2013 Society of Chemical Industry
Enhanced production of pigments by addition of surfactants in submerged fermentation of Monascus purpureus H1102
Authors: Wang Yonghui , Zhang Bobo , Lu Liping , Huang Yan , Xu Ganrong
Published: April 2013

BACKGROUND

The production of pigments by Monascus spp. has attracted increasing attention. Modification of the cell membrane structure by addition of surfactants has proved to be effective for the secretion of intracellular metabolites. Hence in this study the effects and underlying mechanism of surfactants on the production of pigments in submerged fermentation of Monascus purpureus H1102 were systematically investigated.

RESULTS

Various surfactants exerted significant but different impacts on the biomass and production of pigments. The maximum production of pigment (304.3 U mL−1) and highest extracellular/intracellular pigment ratio (1.46) were achieved when 15 g L−1 Triton X‐100 was added at 24 h of fermentation, corresponding to significant increases of 88.4 and 240% respectively compared with the control. Meanwhile, the concentration of citrinin (0.94 mg L−1) was 20.6% lower than that of the control. A further study on the fatty acid composition of M. purpureus H1102 showed that the unsaturated/saturated fatty acid ratio and the index of unsaturated fatty acid increased significantly with the addition of Triton X‐100.

CONCLUSION

The addition of surfactant Triton X‐100 could greatly enhance the production of pigment. It was suggested that Triton X‐100 facilitated the secretion of intracellular pigment and therefore enhanced pigment production accordingly.© 2013 Society of Chemical Industry
Potential risk factors and outcomes of artificial urinary sphincter placement after radical cystectomy and orthotopic neobladder urinary diversion
Authors: Vainrib Michael , Simma‐Chiang Vannita , Boyd Stuart D. , Ginsberg David A.
Published: April 2013

Aims

Stress urinary incontinence (SUI) is a known possibility after radical cystectomy (RC) and orthotopic neobladder (ONB) urinary diversion. We retrospectively reviewed the outcomes and complications of patients who underwent artificial urinary sphincter (AUS) placement for treatment of SUI and evaluated potential risk factors (PRFs) for AUS failure.

Methods

Patients who underwent AUS placement after RC/ONB from 1994 to 2009 were identified. Variables evaluated included: demographics, cancer type, AUS characteristics, urinary incontinence (UI), revision procedures data, and PRFs for AUS failure.

Results

Demographic data was reviewed on 36 patients. Mean age at AUS placement was 72 (58–79) years. Mean time to AUS after RC/ONB was 28 (2–120) months. Mean follow up after AUS was 40 (2–132) months. TCC was the indication for RC in 94% of patients. The most commonly placed AUS cuff and reservoir size was 4.5 cm and 61–70 H2O, respectively. Incontinence data was available in 29 patients. Pre‐AUS placement 22, 3, and 4 patients were totally, daytime and nighttime only incontinent, respectively. Post‐AUS placement, incontinence persisted in 5, 1, and 2 patients with total, daytime and nighttime incontinence, respectively. Prior to AUS placement 11/36 patients received chemotherapy and 10/36 had radiation. Mean time to the first revision/explantation due to UI/erosion/infection/malfunction was an average of 28 (3–96) months after AUS placement and occurred in 21/35 (60%) patients. There was no significant correlation noted between PRFs and UI pre‐/post‐AUS or between PRFs and the need for AUS revision.

Conclusions

AUS is a safe, effective treatment with an acceptable complication rate for patients after RC/ONB with SUI. Neurourol. Urodynam. 32: 1010–1013, 2013. © 2013 Wiley Periodicals, Inc.
Effect of weight loss and exercise on angiogenic factors in the circulation and in adipose tissue in obese subjects
Authors: Cullberg KB , Christiansen T , Paulsen SK , Bruun JM , Pedersen SB , Richelsen B
Published: April 2013

Background:

Vascular growth is a prerequisite for adipose tissue (AT) development and expansion. Some AT cytokines and hormones have effects on vascular development, like vascular endothelial growth factor (VEGF‐A), angiopoietin (ANG‐1), ANG‐2 and angiopoietin‐like protein‐4 (ANGPTL‐4).

Methods:

In this study, the independent and combined effects of diet‐induced weight loss and exercise on AT gene expression and proteins levels of those angiogenic factors were investigated. Seventy‐nine obese males and females were randomized to: 1. Exercise‐only (EXO; 12‐weeks exercise without diet‐restriction), 2. Hypocaloric diet (DIO; 8‐weeks very low energy diet (VLED) + 4‐weeks weight maintenance diet) and 3. Hypocaloric diet and exercise (DEX; 8‐weeks VLED + 4‐weeks weight maintenance diet combined with exercise throughout the 12 weeks). Blood samples and fat biopsies were taken before and after the intervention.

Results:

Weight loss was 3.5 kg in the EXO group and 12.3 kg in the DIO and DEX groups. VEGF‐A protein was non‐significantly reduced in the weight loss groups. ANG‐1 protein levels were significantly reduced 22‐25% after all three interventions (P < 0.01). The ANG‐1/ANG‐2 ratio was also decreased in all three groups (P < 0.05) by 27‐38%. ANGPTL‐4 was increased in the EXO group (15%, P < 0.05) and 9% (P < 0.05) in the DIO group. VEGF‐A, ANG‐1, and ANGPTL‐4 were all expressed in human AT, but only ANGPTL‐4 was influenced by the interventions.

Conclusions:

Our data show that serum VEGF‐A, ANG‐1, ANG‐2, and ANGPTL‐4 levels are influenced by weight changes, indicating the involvement of these factors in the obese state. Moreover, it was found that weight loss generally was associated with a reduced angiogenic activity in the circulation.
A risk adjusted cost‐effectiveness analysis of alternative models of nurse involvement in obesity management in primary care
Authors: Karnon J. , Afzali H. Haji Ali , Gray J. , Holton C. , Banham D. , Beilby J.
Published: April 2013

Objective:

Controlled evaluations are subject to uncertainty regarding their replication in the real world, particularly around systems of service provision. Using routinely collected data, we undertook a risk adjusted cost‐effectiveness (RAC‐E) analysis of alternative applied models of primary health care for the management of obese adult patients. Models were based on the reported level of involvement of practice nurses (registered or enrolled nurses working in general practice) in the provision of clinical‐based activities.

Design and Methods:

Linked, routinely collected clinical data describing clinical outcomes (weight, BMI, and obesity‐related complications) and resource use (primary care, pharmaceutical, and hospital resource use) were collected. Potential confounders were controlled for using propensity weighted regression analyses.

Results:

Relative to low level involvement of practice nurses in the provision of clinical‐based activities to obese patients, high level involvement was associated with lower costs and better outcomes (more patients losing weight, and larger mean reductions in BMI). Excluding hospital costs, high level practice nurse involvement was associated with slightly higher costs. Incrementally, the high level model gets one additional obese patient to lose weight at an additional cost of $6,741, and reduces mean BMI by an additional one point at an additional cost of $563 (upper 95% confidence interval $1,547).

Conclusion:

Converted to quality adjusted life year (QALY) gains, the results provide a strong indication that increased involvement of practice nurses in clinical activities is associated with additional health benefits that are achieved at reasonable additional cost. Dissemination activities and incentives are required to encourage general practices to better integrate practice nurses in the active provision of clinical services.