bluuebunny/crossref_metadata_2025 huggingface dataset:
Large Area Self‐Assembly of Nematic Liquid‐Crystal‐Functionalized Gold Nanorods
Authors: Umadevi S. , Feng Xiang , Hegmann Torsten
Published: October 2012

Fascinating nematic‐ and smectic‐like self‐assembled arrays are observed for gold nanorods partially capped with either laterally or terminally attached nematic liquid crystals upon slow evaporation of an organic solvent on TEM grids. These arrays can be manipulated and reoriented by applying an external magnetic field from quasi‐planar to vertical similar to a Fréedericksz transition of common organic nematic liquid crystals. Birefringence and thin film textures of these self‐assembled gold nanorod arrays observed by polarized optical microscopy are strongly reminiscent of common organic nematic liquid crystal textures between crossed polarizers and, additionally, support the formation of ordered liquid crystal‐like anisotropic superstructures. The ordering within these arrays is also confirmed in bulk samples using small angle X‐ray scattering (SAXS).
Understanding the Role of Thermal Processing in High Performance Solution Processed Small Molecule Bulk Heterojunction Solar Cells
Authors: Leong Wei Lin , Welch Gregory C. , Seifter Jason , Seo Jung Hwa , Bazan Guillermo C. , Heeger Alan J.
Published: October 2012

Two similar structural versions of a molecular donor, in which two terminal hexyl‐substituted bithiophene units are connected to a central dithienosilole (DTS) through electron deficient thiadiazolopyridine (PT) units, and which differ only in the position of pyridyl N‐atoms, were explored to study the interplay of crystallization and vertical phase segregation as a result of annealing. The donor materials exhibit greatly contrasting photovoltaic performance despite similarity in molecule structure. The difference in position of the pyridal N‐atom which points away (distal configuration; compound 1) or towards (proximal configuration; compound 2) from the DTS core, modifies the aggregation/molecular packing in the solid state, resulting in differences in the phase segregation and formation of crystalline domains. A systematic study of the temperature dependence of photovoltaic performance reveals a parameter trade‐off: as annealing temperature increases, higher donor crystallinity and ordering results, but increased donor segregation near the surface or decrease in electrode selectivity also occurs, resulting in increased interfacial recombination and hence reduction in open‐circuit voltage (Voc). The higher crystalline nature of 2 is found to have a higher impact on cell performance despite a competing undesired effect at the donor/aluminum cathode interface, contributing to its superior performance to 1 when blended with [6,6]phenyl‐C61‐butyric acid methyl ester (PC61BM). Molecule 2 exhibits a performance increase of a factor of two after thermal annealing at 100 °C, achieving a power conversion efficiency of 5.7%.
Experimental and numerical study of mixing behavior inside droplets in microchannels
Authors: Wang Wentan , Shao Ting , Zhao Shufang , Jin Yong , Cheng Yi
Published: October 2012

For the practical applications of droplet‐based microfluidics, we have paid special attention to the complex hydrodynamics and mixing performance inside microdroplets and the profound process intensification when forcing the droplets to move in winding channels. In this work, experimental studies using micro laser induced fluorescence (μ‐LIF) technique and three‐dimensional simulation based on a multiphase, multicomponents lattice Boltzmann model approach were adopted. The simulation results clearly revealed that the mixing inside the droplet is due to the convection in symmetric vortices in the two hemispheres of the droplet and the diffusion between them. They also showed the fluids inside the droplet could be reoriented due to the winding effect. Three designs of winding channels were studied, where interesting results showed the similar effect of process intensification by breaking up the flow symmetry. The revealed flow mechanism and the mixing performance inside the droplet in droplet‐based microfluidics should be helpful for microdevice design and optimization. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1801–1813, 2013
Identification of the flow structures and regime transition in gas–solid fluidized beds through moment analysis
Authors: Zhu Jesse , Qi Maozhan , Barghi Shahzad
Published: October 2012

Using statistic parameters of solids holdup signals, a moment consistency data processing method (MCDPM) was proposed. Experiments were carried out using FCC particles of 76 μm under different operating conditions, and MCDPM was used to successfully obtain solids holdups of the dense and dilute phases and the phase fractions over five fluidization regimes, bubbling (BFB), turbulent (TFB), circulating turbulent (CTFB), high‐density circulating (HDCFB), and circulating (CFB) fluidized bed systems. In BFB, TFB, and CTFB regimes, only dense phase fraction decreased with increasing air velocity, while the transition from HDCFB to CFB experienced appreciable change in the solids holdup of the dense phase. From the low‐velocity to the high‐velocity regimes, both the solids holdup and the fraction of the dense phase experienced a drastic decrease, suggesting that this transition corresponded to a profound change in flow structure and further suggesting that CTFB is in reality still a TFB. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1479–1490, 2013
Work organization, job insecurity, and occupational health disparities
Authors: Landsbergis Paul A. , Grzywacz Joseph G. , LaMontagne Anthony D.
Published: October 2012

Background

Changes in employment conditions in the global economy over the past 30 years have led to increased job insecurity and other work organization hazards. These hazards may play a role in creating and sustaining occupational health disparities by socioeconomic position, gender, race, ethnicity, and immigration status.

Methods

A conceptual model was developed to guide the review of 103 relevant articles or chapters on the role of work organization and occupational health disparities identified through a comprehensive search conducted by NIOSH. A second review was conducted of employment and workplace policies and programs designed to reduce the health and safety risks due to job insecurity and other work organization hazards.

Results

There is consistent evidence that workers in lower socioeconomic or social class positions are exposed to greater job insecurity and other work organization hazards than workers in higher socioeconomic positions. Likewise, racial and ethnic minorities and immigrants are exposed to greater job insecurity. Limited research examining the effects of interventions targeting work organization hazards on disparities has been conducted; nonetheless, intervention strategies are available and evidence suggests they are effective.

Conclusions

Job insecurity and work organization hazards play a role in creating and sustaining occupational health disparities. Employment and workplace policies and programs have the potential to reduce these hazards, and to reduce disparities. Am. J. Ind. Med. 57:495–515, 2014. © 2012 Wiley Periodicals, Inc.
Anwendungen der Katalyse mit N‐heterocyclischen Carbenen in Totalsynthesen
Authors: Izquierdo Javier , Hutson Gerri E. , Cohen Daniel T. , Scheidt Karl A.
Published: October 2012

Katalytische Umwandlungen mit N‐heterocyclischen Carbenen (NHCs) haben sich als effiziente Ansätze zum Aufbau komplexer Moleküle erwiesen. Seit der Veröffentlichung von Stetter 1975 zur Totalsynthese von cis‐Jasmon und Dihydrojasmon durch Carbenkatalyse hat sich die Anwendung von NHCs in der Totalsynthese, insbesondere in den letzten zehn Jahren, schnell verbreitet. Dieser Aufschwung ist zweifellos die Folge neuerer Entwicklungen bei NHC‐katalysierten Reaktionen, einschließlich der neuen Benzoin‐, Stetter‐, Homoenolat‐ und Aroylierungsprozesse. Die Umwandlungen ermöglichen ebenso typische wie auf Umpolung beruhende Bindungsbildungen und sind bereits als Schlüsselschritte in mehreren neuen Totalsynthesen aufgetreten. Dieser Kurzaufsatz beschreibt diese neuen Arbeiten und zeigt die verstärkten Einsatzmöglichkeiten der Carbenkatalyse in der Totalsynthese auf.
A Continuum of Progress: Applications of N‐Hetereocyclic Carbene Catalysis in Total Synthesis
Authors: Izquierdo Javier , Hutson Gerri E. , Cohen Daniel T. , Scheidt Karl A.
Published: October 2012

N‐Heterocyclic carbene (NHC) catalyzed transformations have emerged as powerful tactics for the construction of complex molecules. Since Stetter’s report in 1975 of the total synthesis of cis‐jasmon and dihydrojasmon by using carbene catalysis, the use of NHCs in total synthesis has grown rapidly, particularly over the last decade. This renaissance is undoubtedly due to the recent developments in NHC‐catalyzed reactions, including new benzoin, Stetter, homoenolate, and aroylation processes. These transformations employ typical as well as Umpolung types of bond disconnections and have served as the key step in several new total syntheses. This Minireview highlights these reports and captures the excitement and emerging synthetic utility of carbene catalysis in total synthesis.
Physical gels of [BMIM][BF4] by N‐ tert‐butylacrylamide/ethylene oxide based triblock copolymer self‐assembly: Synthesis, thermomechanical, and conducting properties
Authors: Sharma Nitin , Lakhman Rubinder Kaur , Zhou Yuxiang , Kasi Rajeswari M.
Published: October 2012

We report a strategy to prepare and characterize mechanically robust, transparent, thermoreversible physical gels of an ionic liquid 1‐butyl‐3‐methylimidazolium tetrafluoroborate, [BMIM][BF4], to harness its good ionic conductivity and electrolytic properties for solid‐state electrolyte and lithium ion battery applications. Physical gels are prepared using a triblock copolymer comprising central polyethylene oxide block that is soluble in [BMIM][BF4] and the end blocks, poly(N‐tert‐butylacrylamide), that are insoluble in [BMIM][BF4]. Transparent, strong, physical ion‐gels with significant mechanical strength can be formed at low concentration of the triblock copolymer (∼5 wt %), unlike previous reports in which chemical gels of [BMIM][BF4] are obtained at very high polymer concentration. Our gels are thermoreversible and thermally stable, showing 1–4% weight loss up to 200°C in air. Gelation behavior, mechanical properties, and ionic conductivity of these ion‐gels can be easily tuned by varying the concentration or N‐tert‐butylacrylamide block length in the triblock copolymer. These new non‐volatile, reprocessable, mechanically robust, [BMIM][BF4]‐based physical ion‐gels obtained from a simple and convenient preparation method are promising materials for solid‐state electrolyte applications. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Effect of pyridazine content and crosslinker structure on the properties of polyurethane elastomers
Authors: Oprea Stefan
Published: October 2012

This article studies the development of a series of heterocyclic polyurethanes (PUs) with various pyridazine content and different crosslinker structure in their main chains. All of the isocyanate‐terminated PU prepolymers were prepared from poly(tetramethylene oxide) glycol of molecular weight 1400 (Terathane 1400) and 1,6‐hexamethylene diisocyanate. The properties of the obtained linear and crosslinked pyridazine‐based PU were compared with the properties of common PUs obtained by chain extension with 1,4‐butanediol. All the obtained PUs were characterized through spectral and thermal behavior. The pyridazine‐based PU showed improved thermal stability with 10% weight loss at temperatures above 370–400°C. With the increase of pyridazine content the values of Young's modulus are higher and the strain at break decreases. Increasing pyridazine content leads to increased films surface hydrophilicity. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Rubber‐toughened PLA blends with low thermal expansion
Authors: Jiang Jiandi , Su Lili , Zhang Kun , Wu Guozhang
Published: October 2012

In this study, poly (lactic acid) (PLA) blended with various rubber components, i.e., poly (ethylene‐glycidyl methacrylate) (EGMA), maleic anhydride grafted poly(styrene‐ethylene/butylene‐styrene) triblock elastomer (m‐SEBS), and poly(ethylene‐co‐octene) (EOR), was investigated. It was observed that EGMA is highly compatible due to its reaction with PLA. m‐SEBS is less compatible with PLA and EOR is incompatible with PLA. Electron microscopy (SEM and TEM) revealed that a fine co‐continuous microlayer structure is formed in the injection‐molded PLA/EGMA blends. This leads to polymer blends with high toughness and very low linear thermal expansion both in the flow direction and in the transverse direction. The microlayer thickness of rubber in PLA blends was found to play key roles in reducing the linear thermal expansion and achieving high toughness of the blends. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Adsorption of organic amines from wastewater by carboxyl group‐modified polyacrylonitrile fibers
Authors: Sha Baofeng , Wang Jing , Zhou Lili , Zhang Xiaozhuan , Han Luoli , Zhao Liang
Published: October 2012

In this study, hexamethylenediamine (HMD) and hexamethyleneimine (HMI) were removed from a real wastewater by carboxyl group‐modified polyacrylonitrile (RPFC‐I) fibers. Adsorption of organic amines by fibrous absorbents is a new technique. Adsorption by fibers has advantages of fast kinetic, high adsorption capacity, and efficiency. Moreover, the fibers could be repeatedly used after regeneration. Batch adsorption tests were conducted to investigate adsorption comparison of the three fibers, adsorption kinetic, adsorption isotherms, regeneration, and readsorption stability. The experiments showed that RPFC‐I fibers had excellent adsorption capacity for HMI and HMD. The adsorption equilibrium was achieved very fast within about 5 min, and the removal rate of total nitrogen (TN) was above 99%. The adsorption kinetic could be well fitted by the pseudo‐second‐order equation. And the adsorption isotherm could be well fitted by the Langmuir model. The estimated maximum adsorption capacity was 105.2 mg g−1, nearly similar with cation exchange capacity (CEC) of RPFC‐I fibers. Results from adsorption stability tests demonstrated that the RPFC‐I fibers could be fully regenerated by HCl and the regenerated fibers could be repeatedly used even after 12 adsorption–desorption cycles. Analyses from Fourier transform infrared and the adsorption tests suggested that chemical reaction between carboxyl groups and organic amines was the main mechanism for removal of HMI and HMD from the wastewater. The RPFC‐I fibers prepared in the current study have a wide application in wastewater treatment and useful substance recovery. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Ontogenetic and Structural Variation of Mineralizations and Ossifications in the Integument within Ceratophryid Frogs (Anura, Ceratophryidae)
Authors: Quinzio Silvia , Fabrezi Marissa
Published: October 2012

Ceratophryidae represent a monophyletic group of terrestrial and aquatic frogs inhabiting lowlands of South America where they are more diverse in semiarid environments of the Chaco region. Adult morphology of ceratophryids presents some features associated to terrestrial and fossorial life such as hyper‐ossified skulls, spade feet for digging, among others. For anurans, different mineralized structures have been described in the integument as calcium reservoirs and related to the terrestrial life and water balance (e.g., the calcified layer and dermal ossifications). We describe the ontogeny of the integument in the three genera of ceratophryids (Chacophrys, Ceratophrys, and Lepidobatrachus) that inhabit in semiarid environments. Data obtained demonstrated the early acquisition of metamorphic transformations in the integument layers in larvae of Ceratophrys cranwelli and Lepidobatrachus spp. and a continuous increment in the thickness of them up to old postmetamorphic stages. The integument of ceratophryids develops calcium deposits as the calcified layer during postmetamorphic stages. Furthermore, dorsal shields are also present in adult stages independently of terrestrial versus aquatic lifestyles. While the calcified layer seems to be a feature of a fully developed integument, in which their layers have acquired the adult thickness, dorsal shields develop at premetamorphic stages in L. llanensis and postmetamorphic individuals of C. cranwelli. In ceratophryids, similar to other studied taxa (e.g., Brachycephalus spp.) dorsal shields develop via an intramembranous ossification in which the calcified layer does not precede its differentiation. Within anurans, the occurrence of dorsal shields in the monophyletic ceratophryids suggested a distinctive evolutionary history in the lineage. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.
Design for learning: Adapting the microscopic anatomy laboratory to adult learners
Authors: Jurjus Rosalyn A. , Krum Janette , Goldman Ellen F.
Published: October 2012

Medical school curricula are undergoing transformational change in response to calls for integrating content across courses and years to enable better retention and application and for individualizing learning to meet the diverse backgrounds and thus differing needs of students. To address the related teaching challenges, faculty can employ solid principles of adult learning and instructional design and use teaching strategies that stimulate different learning styles. We developed laboratory sessions that follow a learner‐centered instructional design model we refer to as “PLHET,” reflecting the steps of preparing, linking, hooking, engaging, and transferring learning, and also applied teaching strategies that reflect Kolb's four styles of learning (accommodative, divergent, assimilative, and convergent). We utilized a group learning format to promote active learning, teamwork, and self‐direction. Preliminary data based on student surveys of laboratory activity show positive responses. In the future, we will test the hypothesis that this design will improve medical students' performance. Anat Sci Educ © 2013 American Association of Anatomists.
Identifying interdisciplinarity through the disciplinary classification of coauthors of scientific publications
Authors: Abramo Giovanni , D'Angelo Ciriaco Andrea , Di Costa Flavia
Published: October 2012

The growing complexity of challenges involved in scientific progress demands ever more frequent application of competencies and knowledge from different scientific fields. The present work analyzes the degree of collaboration among scientists from different disciplines to identify the most frequent “combinations of knowledge” in research activity. The methodology adopts an innovative bibliometric approach based on the disciplinary affiliation of publication coauthors. The field of observation includes all publications (167,179) indexed in the Science Citation Index Expanded for the years 2004–2008, authored by all scientists in the hard sciences (43,223) at Italian universities (68). The analysis examines 205 research fields grouped in 9 disciplines. Identifying the fields with the highest potential of interdisciplinary collaboration is useful to inform research polices at the national and regional levels, as well as management strategies at the institutional level.
Internet health search: When process complements goals
Authors: Hong Traci
Published: October 2012

This study examines how the goal orientation of individuals, rather than the goals of a search task, influences information search behavior for 2 discrete stages of the Internet search process. In an Internet‐based experiment (N = 106) with temporarily activated motivational orientation (promotion vs. prevention) and message goal frames (gain vs. loss) as independent variables, it was demonstrated that participants selected information that was congruent with their motivational orientation although they did not necessarily spend more time attending to their selection. Participants with the promotion orientation exhibited more scanning behavior and viewed more web pages but spent less time on the Internet search. Congruency effects resulted in higher user engagement, which mediated the congruency effects on the perceived message quality of the health content.
A theoretical foundation for the relationship between generalized origin–destination matrix and flow matrix based on ordinal graph trajectories
Authors: Teknomo Kardi , Fernandez Proceso
Published: October 2012

This paper shows the relationship between flow, generalized origin–destination (OD), and alternative route flow from a set of ordinal graph trajectories. In contrast to traffic assignment methods that employ OD matrix to produce flow matrix, we use ordinal trajectory on a network graph as input and produce both the generalized OD matrix and the flow matrix, with the alternative and substitute route flow matrices as additional outputs. By using linear algebra‐like operations on matrix sets, the relationship between network utilization (in terms of flow, generalized OD, alternative route flow, and desire line) and network structure (in terms of distance matrix and adjacency matrix) are derived. Copyright © 2012 John Wiley & Sons, Ltd.
Characterization of luminescent Vibrio campbelliiLZ5 and its potential application in the detection of environmental heavy metals
Authors: Liu Zhu , Zhao Junqiao , Liang Xiaojie , Li Kongpan , Xiao Xiang , Zhu Jianqing , Sun Qun , Liang Quanfeng
Published: October 2012

A luminescent strain was isolated and identified as Vibrio campbellii strain LZ5 by 16S rDNA analysis. It grew well in broad living conditions, and the relative fluorescence intensity was stable at pH ranging from 5 to 7.5, NaCl concentrations from 0% to 3%, KCl from 1.5% to 5%, and CaCl2 from 1% to 3%. In contrast, the relative fluorescence intensity was negatively correlated with both CdCl2 and HgCl2 concentrations from 0 to 1 mg/L. The luminescent fraction from the cell lysate was purified by ion‐exchange chromatography, and identified as a luciferase by using matrix‐assisted laser desorption/ionization–time of flight mass spectrometry. Furthermore, the biofilm of V. campbellii LZ5 was formed constantly under different conditions, and was not affected by heavy metal ions. The data collectively reveal that strain LZ5 has the potential to be developed into a biosensor for real‐time monitoring of heavy metals.
Product developments in the bio‐based chemicals arena
Authors: de Jong Ed , Higson Adrian , Walsh Patrick , Wellisch Maria
Published: October 2012

Around the world, significant able steps are being taken to move from today's fossil‐based economy to a more sustainable economy based on biomass. A key factor in the realization of a successful bio‐based economy will be the development of biorefinery systems allowing highly efficient and cost‐effective processing of biological feedstocks to a range of bio‐based products, and successful integration into existing infrastructure. The recent climb in oil prices and consumer demand for environmentally friendly products has now opened new windows of opportunity for bio‐based chemicals and polymers. Industry is increasingly viewing chemical and polymer production from renewable resources as an attractive area for investment. Within the bio‐based economy and the operation of a biorefinery, there are significant opportunities for the development of bio‐based building blocks (chemicals and polymers) and materials (fiber products, starch derivatives, etc.). In many cases this happens in conjunction with the production of bioenergy or biofuels. The production of bio‐based products could generateUS$10–15 billion ofrevenue for the global chemical industry. The economic production of biofuels is often a challenge. The co‐‐production of chemicals, materials food and feed can generate the necessary added value. This paper highlights all bio‐based chemicals with immediate potential as biorefinery ‘value added products’. The selected products are either demonstrating strong market growth or have significant industry investment in development and demonstration programs. The fullIEABioenergy Task 42 report is available fromhttp://www.iea-bioenergy.task42-biorefineries.com© Her Majesty the Queen in Right of Canada 2012
Altered infant feeding patterns in boys with acquired nonsyndromic cryptorchidism
Authors: Barthold Julia Spencer , Hossain Jobayer , Olivant‐Fisher Alicia , Reilly Anita , Figueroa T. Ernesto , BaniHani Ahmad , Hagerty Jennifer , González Ricardo , Noh Paul H. , Manson Jeanne M.
Published: October 2012

BACKGROUND: Genetic and environmental factors likely influence susceptibility to nonsyndromic cryptorchidism, a common disease presenting at birth or in later childhood. We compared cases and controls to define differential risk factors for congenital versus acquired cryptorchidism. METHODS: We compared questionnaire and clinical data from cases of congenital cryptorchidism (n = 230), acquired cryptorchidism (n = 182) and hernia/hydrocele (n = 104) with a group of healthy male controls (n = 358). Potential predictor variables (p < 0.2 in univariable analysis) were included in stepwise multivariable logistic regression models. RESULTS: Temporary (odds ratio [OR], 0.5; 95% confidence interval [CI], 0.4–0.8) or exclusive (OR, 0.6; 95% CI, 0.4–0.9) breastfeeding was reduced and soy formula feeding increased (OR, 1.8; 95% CI, 1.2–2.9) in acquired but not congenital or hernia/hydrocele groups. The highest risk estimates were observed for primary soy formula feeding with limited or no breastfeeding (OR 2.5; 95% CI, 1.4–4.3; adjusted OR, 2.7; 95% CI, 1.4–5.4) in the acquired group. Primary feeding risk estimates were equivalent or strengthened when multivariable models were limited to age greater than 2 years, full‐term or not small for gestational age, or Caucasian subjects. Pregnancy complications and increased maternal exposure to cosmetic or household chemicals were not consistently associated with either form of cryptorchidism in these models. CONCLUSIONS: Our data support reduced breastfeeding and soy formula feeding as potential risk factors for acquired cryptorchidism. Although additional studies are needed, hormonally active components of breast milk and soy formula could influence the establishment of normal testis position in the first months of life, leading to apparent ascent of testes in childhood. Birth Defects Research (Part A), 2012. © 2012 Wiley Periodicals, Inc.
Metabolic profile of glyburide in human liver microsomes using LC‐DAD‐Q‐TRAP‐MS/MS
Authors: Ravindran Selvan , Basu Sudipta , Gorti Santosh Kapil Kumar , Surve Prashant , Sloka Navya
Published: October 2012

The sulfonylurea urea drug glyburide (glibenclamide) is widely used for the treatment of diabetes milletus and gestational diabetes. In previous studies monohydroxylated metabolites were identified and characterized for glyburide in different species, but the metabolite owing to the loss of cyclohexyl ring was identified only in mouse. Glyburide upon incubation with hepatic microsomes resulted in 10 metabolites for human. The current study identifies new metabolites of glyburide along with the hydroxylated metabolites that were reported earlier. The newly identified drug metabolites are dihydroxylated metabolites, a metabolite owing to the loss of cyclohexyl ring and one owing to hydroxylation with dehydrogenation. Among the 10 identified metabolites, there were six monohydroxylated metabolites, one dihydroxylated metabolite, two metabolites owing to hydroxylation and dehydrogenation, and one metabolite owing to the loss of cyclohexyl ring. New metabolites of glyburide were identified and characterized using liquid chromatography–diode array detector–quadruple‐ion trap–mass spectrometry/mass spectrometry (LC‐DAD‐Q‐TRAP‐MS/MS). An enhanced mass scan–enhanced product ion scan with information‐dependent acquisition mode in a Q‐TRAP‐MS/MS system was used to characterize the metabolites. Liquid chromatography with diode array detection was used as a complimentary technique to confirm and identify the metabolites. Metabolites formed in higher amounts were detected in both diode array detection and mass spectrometry detection. Copyright © 2012 John Wiley & Sons, Ltd.
Low dose aspirin estimation: an application to a human pharmacokinetic study
Authors: Vijaya Bharathi D. , Hotha Kishore Kumar , Kolagatla Pandu Ranga Reddy , Venkateswarlu V.
Published: October 2012

Low dose to very high dose aspirin is used to prevent heart attack. We have developed and validated a sensitive and robust method that could detect low levels of aspirin and salicylic acid in plasma and also a novel sample collection procedure to carry out sample preparation at room temperature. The total run time was 3.00 min; the developed method was validated in human plasma with a lower limit of quantitation of 0.99 ng/mL for aspirin and 2.01 ng/mL for salicylic acid. A linear response function was established for the range of concentrations 0.99–756.20 ng/mL (r > 0.998) for aspirin and 2.01–2486.86 ng/mL for salicylic acid. The intra‐ and inter‐day precision values for aspirin and salicylic acid met the acceptance as per FDA guidelines. The developed assay method was applied to an oral pharmacokinetic study in humans. Copyright © 2012 John Wiley & Sons, Ltd.
Stereospecific analytical method development and preliminary in vivo pharmacokinetic characterization of pinostrobin in the rat
Authors: Sayre Casey L. , Zhang Yangmiao , Martinez Stephanie E. , Takemoto Jody K. , Davies Neal M.
Published: October 2012

The complete pharmacokinetic disposition of the chiral flavonoid (±) pinostrobin remains unknown without the development of an analytical method of detection and quantitation of its individual enantiomers. Resolution of the enantiomers of pinostrobin was achieved using as simple high‐performance liquid chromatographic method. A Chiralpak® AD‐RH column was employed to perform baseline separation with UV detection at 287 nm. The standard curves were linear ranging from 0.5 to 100 µg/mL for each enantiomer. The limit of quantification was 0.5 µg/mL. Precision and accuracy of the assay was < 15% (RSD) and was with a bias <15% for all points on the calibration curve. The assay was applied successfully to stereoselective serum disposition of pinostrobin enantiomers in rats. Both enantiomers had a serum half‐life of ~7 h. They also shared similar values of volume of distribution (Vd S‐pinostrobin, 8.2 L/kg; Vd R‐pinostrobin, 8.9 L/kg), total clearance (S‐pinostrobin CLtotal, 0.959 L//h/kg; R‐pinostrobin CLtotal, 1.055 L//h/kg), and area under the curve (S‐pinostrobin AUCinf, 23.16 µg h/mL; R‐pinostrobin AUCinf, 21.296 µg h/mL). The large volume of distribution suggests extensive distribution of pinostrobin into tissues. Copyright © 2012 John Wiley & Sons, Ltd.
Novel Zierane‐ and Guaiane‐Type Sesquiterpenes from the Root of Melicope denhamii
Authors: Nakashima Ken‐ichi , Oyama Masayoshi , Ito Tetsuro , Witono Joko Ridho , Darnaedi Dedy , Tanaka Toshiyuki , Murata Jin , Iinuma Munekazu
Published: October 2012

Two novel zierane‐type sesquiterpenes, named melicodenones A and B (1 and 2, resp.), and three new guaiane‐type sesquiterpenes, named melicodenones C–E (3–5), were isolated from the root of Melicope denhamii (Seem.) T. G. Hartley together with zierone (6). Their structures were established by extensive NMR‐spectroscopic analyses. Compounds 1–6 were tested for cytotoxicity using human colon cancer DLD‐1 cells, and melicodenone A (1) was found to exhibit moderate activity.
Endogenous CSE/H2S system mediates TNF‐α‐induced insulin resistance in 3T3‐L1 adipocytes
Authors: Huang Ci‐You , Yao Wei‐Feng , Wu Wei‐guo , Lu Yu‐Lian , Wan Hui , Wang Wen
Published: October 2012

Tumour necrosis factor‐α (TNF‐ α)is a major contributor to the pathogenesis of insulin resistance associated with obesity and type 2 diabetes. It has been found that endogenous hydrogen sulfide (H2S) contributes to the pathogenesis of diabetes. We have hypothesized that TNF‐α‐induced insulin resistance is involved in endogenous H2S generation. The aim of the present study is to investigate the role of endogenous H2S in TNF‐α‐induced insulin resistance by studying 3T3‐L1 adipocytes. We found that treatment of 3T3‐L1 adipocytes with TNF‐α leads to deficiency in insulin‐stimulated glucose consumption and uptake and increase in endogenous H2S generation. We show that cystathionine γ‐lyase (CSE) is catalysed in 3T3‐L1 adipocytes to generate H2S and that CSE expression and activity are upregulated by TNF‐α treatment. Inhibited CSE by its potent inhibitors significantly attenuates TNF‐α‐induced insulin resistance in 3T3‐L1 adipocytes, whereas H2S treatment of 3T3‐L1 adipocytes impairs insulin‐stimulated glucose consumption and uptake. These data indicate that endogenous CSE/H2S system contributes to TNF‐α‐caused insulin resistance in 3T3‐L1 adipocytes. Our findings suggest that modulation of CSE/H2S system is a potential therapeutic avenue for insulin resistance. Copyright © 2012 John Wiley & Sons, Ltd.
Coronary reperfusion and clinical outcomes after thrombus aspiration during primary percutaneous coronary intervention: Findings from the HORIZONS‐AMI trial
Authors: Nilsen Dennis W.T. , Mehran Roxana , Wu Roland S. , Yu Jennifer , Nordrehaug Jan E. , Brodie Bruce R. , Witzenbichler Bernhard , Nikolsky Eugenia , Fahy Martin , Stone Gregg W.
Published: October 2012

Objectives

To assess the quality of coronary reperfusion and long‐term clinical outcomes of patients enrolled in the HORIZONS‐AMI trial according to the use of thrombus aspiration (TA).

Background

The impact of manual TA on microvascular perfusion and clinical outcomes in patients with ST‐segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) is unsettled.

Methods

In this retrospective, nonrandomized, subgroup analysis, the authors evaluated thrombolysis in myocardial infarction (TIMI) flow, tissue myocardial perfusion grade (TMPG), ST‐segment resolution (STR), net adverse clinical events (NACE), and major adverse cardiac events (MACE) in patients undergoing pPCI with or without manual TA.

Results

A total of 318 patients had pPCI with upfront TA, and 2,917 patients had pPCI without TA. Patients who had TA were more likely to have TIMI 0/1 flow at baseline (75.1% vs. 63.7%, P < 0.0001). There was no difference in the rates of final TIMI 3 flow (90.2% vs. 92.3%, P = 0.19) or dynamic TMPG 2‐3 (77.4% vs. 76.4%, P = 0.68). STR ≥70% was similar in both groups at 60 minutes but higher in the TA group at discharge (71.8% vs. 64.6%, P = 0.02). After multivariable adjustment, TA did not predict MACE at 30 days (HR 0.96 [0.51–1.80], P = 0.90), 1 year (HR 1.03 [0.68–1.55], P = 0.89), or 3 years (HR 1.13 [0.86–1.48], P = 0.39). Stent thrombosis did not differ at 1 year or 3 years.

Conclusions

In STEMI patients undergoing pPCI, the use of manual TA was associated with improved STR at discharge, but not with any difference in final TIMI flow, TMPG, or MACE. © 2012 Wiley Periodicals, Inc.
Patent ductus arteriosus closure using the amplatzer® vascular plug II for all anatomic variants
Authors: Delaney Jeffrey W. , Fletcher Scott E.
Published: October 2012

Objectives

To evaluate the safety and efficacy of the Amplatzer® Vascular Plug II (AVPII) for closure of the patent ductus arteriosus (PDA).

Background

The PDA has significant anatomic variation. No device has proven applicable to all PDAs. Previous case reports and small series have documented limited use of the AVPII for some PDA types. We describe the largest and most diverse experience using the AVPII.

Methods

A retrospective analysis of patients undergoing percutaneous PDA closure between 01/01/2009 and 05/01/2012 was performed. The PDA was characterized, measured, and the device chosen was listed. Deployment technique, complications and procedural results were recorded.

Results

Sixty‐seven procedures were performed. The AVPII was utilized for 43 (64.2%), 15 (20.9%) had coils, 7 (10.4%) had the AGA duct occluder, and 3 (4.5%) were referred for surgery. The AVPII was placed in infants as young as 2 months and 4.2 kg. AVPII size ranged from 4 to 10 mm. All PDA types were closed. Retrograde and antegrade deployments were performed, using the outer disc as a “retention skirt” to secure the device and improve occlusion. Three patients were up‐sized prior to release. All deployments were successful; 89% “in‐lab” and 100% closure on postprocedural echocardiogram. There were no complications.

Conclusions

We report the largest experience with the AVPII for PDA closure. The device was used in all morphologic types and small patients. It is low profile, easily repositioned, and had excellent results without complications. We contend that this is the most versatile device currently available. © 2012 Wiley Periodicals, Inc.
Impact of stent implantation on pulmonary artery growth
Authors: Takao Cheryl M. , El Said Howaida , Connolly Dana , Hamzeh Rabih K. , Ing Frank F.
Published: October 2012

Background

Goals of stent implantation (SI) in children with pulmonary artery (PA) stenosis are to relieve obstruction and improve flow to the distal vasculature. We evaluated stent impact on distal PA growth.

Methods

We compared data of children who underwent unilateral SI using the nonstenotic contralateral PA (CPA) as a control (1998–2005; f/u data through 2009). Main/lobar diameters measured at initial and f/u catheterizations were analyzed.

Results

For single ventricle (SV) patients (N = 18), the stented PA diameter (SPA D) increased 118%. At initial f/u catheterization (14 ± 9.6 months), both upper lobe (UL) and lower lobe (LL) growth of SPA was comparable to those of the CPA (UL:7% vs. 7%; P = 0.97); (LL:5% vs. 10%; P = 0.33). Subsequent f/u in 11/18 patients (mean 26 ± 20 months) revealed similar results: both UL and LL growth of SPA were comparable to those of the CPA (UL:51% vs. 27%; P = 0.3); (LL:18% vs. 21%; P = 0.62). For two‐ventricle (2V) patients (N = 21), the SPAD increased 100%. At f/u, UL, and LL growth on SPA was similar to those of the CPA (UL: 32% vs. 21%; P = 0.37); (LL: 17% vs. 18%; P = 0.88). Subsequent f/u in 10/21 patients (mean 34 ± 14 months) showed UL growth of SPA was significantly greater than that of the CPA (44% vs. 21%; P = 0.05). LL growth of SPA was similar to that of the CPA (19% vs. 14%; P = 0.56).

Conclusion

SI for PA stenosis is effective in promoting normal lobar growth in SV and 2V patients. Greater lobar growth was seen in 2V compared to SV pts at first f/u. Early, aggressive PA stenting is beneficial in promoting lobar branch growth. © 2013 Wiley Periodicals, Inc.
Wide‐Range Light‐Harvesting Donor–Acceptor Assemblies through Specific Intergelator Interactions via Self‐Assembly
Authors: Samanta Suman K. , Bhattacharya Santanu
Published: October 2012

We have synthesized two new low‐molecular‐mass organogelators based on tri‐p‐phenylene vinylene derivatives, one of which could be designated as the donor whereas the other one is an acceptor. These were prepared specifically to show the intergelator interactions at the molecular level by using donor–acceptor self‐assembly to achieve appropriate control over their macroscopic properties. Intermolecular hydrogen‐bonding, π‐stacking, and van der Waals interactions operate for both the individual components and the mixtures, leading to the formation of gels in the chosen organic solvents. Evidence for intergelator interactions was acquired from various spectroscopic, microscopic, thermal, and mechanical investigations. Due to the photochromic nature of these molecules, interesting photophysical properties, such as solvatochromism and J‐type aggregation, were clearly observed. An efficient energy transfer was exhibited by the mixture of donor–acceptor assemblies. An array of four chromophores was built up by inclusion of two known dyes (anthracene and rhodamine 6G) for the energy‐transfer studies. Interestingly, an energy‐transfer cascade was observed in the assembly of four chromophores in a particular order (anthracene‐donor‐acceptor‐rhodamine 6G), and if one of the components was removed from the assembly the energy transfer process was discontinued. This allowed the build up of a light‐harvesting process with a wide range. Excitation at one end produces an emission at the other end of the assembly.
Unraveling the Role of Water in the Stereoselective Step of Aqueous Proline‐Catalyzed Aldol Reactions
Authors: Ribas‐Arino Jordi , Carvajal Maria Angels , Chaumont Alain , Masia Marco
Published: October 2012

A multiscale computational study was performed with the aim of tracing the source of stereoselectivity and disclosing the role of water in the stereoselective step of propionaldehyde aldol self‐condensation catalyzed by proline amide in water, a reaction that serves as a model for aqueous organocatalytic aldol condensations. Solvent mixing and hydration behavior were assessed by classical molecular dynamics simulations, which show that the reaction between propanal and the corresponding enamine takes place in a fully hydrated environment. First‐principles molecular dynamics simulations were used to study the free‐energy profile of four possible reaction paths, each of which yields a different stereoisomer, and high‐level static first‐principles calculations were employed to characterize the transition states for microsolvated species. The first solvation shell of the oxygen atom of the electrophilic aldehyde at the transition states contains two water molecules, each of which donates one hydrogen bond to the nascent alkoxide and thereby largely stabilizes its excess electron density. The stereoselectivity originates in an extra hydrogen bond donated by the amido group of proline amide in two reaction paths.
Poly(acrylic acid)‐Modified Fe3O4 Microspheres for Magnetic‐Targeted and pH‐Triggered Anticancer Drug Delivery
Authors: Kang Xiao‐Jiao , Dai Yun‐Lu , Ma Ping‐An , Yang Dong‐Mei , Li Chun‐Xia , Hou Zhi‐Yao , Cheng Zi‐Yong , Lin Jun
Published: October 2012

Monodisperse poly(acrylic acid)‐modified Fe3O4 (PAA@Fe3O4) hybrid microspheres with dual responses (magnetic field and pH) were successfully fabricated. The PAA polymer was encapsulated into the inner cavity of Fe3O4 hollow spheres by a vacuum‐casting route and photo‐initiated polymerization. TEM images show that the samples consist of monodisperse porous spheres with a diameter around 200 nm. The Fe3O4 spheres, after modification with the PAA polymer, still possess enough space to hold guest molecules. We selected doxorubicin (DOX) as a model drug to investigate the drug loading and release behavior of as‐prepared composites. The release of DOX molecules was strongly dependent on the pH value due to the unique property of PAA. The HeLa cell‐uptake process of DOX‐loaded PAA@Fe3O4 was observed by confocal laser scanning microscopy (CLSM). After being incubated with HeLa cells under magnet magnetically guided conditions, the cytotoxtic effects of DOX‐loaded PAA@Fe3O4 increased. These results indicate that pH‐responsive magnetic PAA@Fe3O4 spheres have the potential to be used as anticancer drug carriers.
Photochemistry of fac‐[Re(bpy)(CO)3Cl]
Authors: Sato Shunsuke , Matubara Yasuo , Koike Kazuhide , Falkenström Magnus , Katayama Tetsuro , Ishibashi Yukihide , Miyasaka Hiroshi , Taniguchi Seiji , Chosrowjan Haik , Mataga Noboru , Fukazawa Naoto , Koshihara Shinya , Onda Ken , Ishitani Osamu
Published: October 2012

The photochemistry of fac‐[Re(bpy)(CO)3Cl] (1 a; bpy=2,2′‐bipyridine) initiated by irradiation using <330 nm light has been investigated. Isomerization proceeded in THF to give the corresponding mer‐isomer 1 b. However, in the presence of a small amount of MeCN, the main product was the CO‐ligand‐substituted complex (OC‐6‐24)‐[Re(bpy)(CO)2Cl(MeCN)] (2 c; bpy=2,2′‐bipyridine). In MeCN, two isomers, 2 c and its (OC‐6‐34) form (2 a), were produced. Only 2 c thermally isomerized to produce the (OC‐6‐44) form 2 b. A detailed investigation led to the conclusion that both 1 b and 2 c are produced by a dissociative mechanism, whereas 2 a forms by an associative mechanism. A comparison of the ultrafast transient UV‐visible absorption, emission, and IR spectra of 1 a acquired by excitation using higher‐energy light (e.g., 270 nm) and lower‐energy light (e.g., 400 nm) gave detailed information about the excited states, intermediates, and kinetics of the photochemical reactions and photophysical processes of 1 a. Irradiation of 1 a using the higher‐energy light resulted in the generation of the higher singlet excited state with τ≤25 fs, from which intersystem crossing proceeded to give the higher triplet state (3HES(1)). In THF, 3HES(1) was competitively converted to both the triplet ligand field (3LF) and metal‐to‐ligand charge transfer (3MLCT) with lifetimes of 200 fs, in which the former is a reactive state that converts to [Re(bpy)(CO)2Cl(thf)]+ (1 c) within 10 ps by means of a dissociative mechanism. Re‐coordination of CO to 1 c gives both 1 a and 1 b. In MeCN, irradiation of 1 a by using high‐energy light gives the coordinatively unsaturated complex, which rapidly converted to 2 c. A seven‐coordinate complex is also produced within several hundred femtoseconds, which is converted to 2 a within several hundred picoseconds.
ChemInform Abstract: Elongation of Planar Boron Clusters by Hydrogenation: Boron Analogues of Polyenes.
Authors: Li Wei‐Li , Romanescu Constantin , Jian Tian , Wang Lai‐Sheng
Published: October 2012

H2Bn‐ (n = 7—12) clusters are generated by laser vaporization of an isotopically enriched 11B target with helium containing 5% D2 as the carrier gas.
ChemInform Abstract: New Rare‐Earth Metal Germanides Ln2Ge9 (Ln: Nd, Sm) by Thermal Decomposition of High‐Pressure Phases LnGe5.
Authors: Meier Katrin , Wosylus Aron , Cardoso‐Gil Raul , Burkhardt Ulrich , Curfs Caroline , Hanfland Michael , Grin Yuri , Schwarz Ulrich
Published: October 2012

The title compounds are prepared by thermal decomposition of the metastable phases LnGe5 (obtained by arc‐melting of the elements at 923—1123 K and 8.3—9.5 GPa) at 543—573 K and ambient pressure for 2 h.
ChemInform Abstract: Zr2N2Se: The First Zirconium(IV) Nitride Selenide by the Oxidation of Zirconium(III) Nitride with Selenium.
Authors: Lissner Falk , Hack Bettina , Lerch Martin , Schleid Thomas
Published: October 2012

The title compound is prepared by reaction of ZrN (obtained by reaction of ZrCl4 with gaseous NH3) and Se in a NaCl flux (evacuated silica tube, 900 °C, 7 d).
ChemInform Abstract: Synthesis, Crystal, and Electronic Structure of the New Ternary Zintl Phase Eu2‐xMg2‐yGe3 (x = 0.1; y = 0.5).
Authors: Slabon Adam , Cuervo‐Reyes Eduardo , Kubata Christof , Woerle Michael , Mensing Christian , Nesper Reinhard
Published: October 2012

The title compound is synthesized by solid state reaction of the elements (Nb ampule, 1020 °C, 48 h followed by 850 °C for 5 d) and characterized by single crystal XRD, magnetic, electrical resistivity, and specific heat measurements, and DFT electronic structure calculations.
ChemInform Abstract: Catalyst Development for Organocatalytic Hydrosilylation of Aromatic Ketones and Ketimines.
Authors: Malkov Andrei V. , Stewart‐Liddon Angus J. P. , McGeoch Grant D. , Ramirez‐Lopez Pedro , Kocovsky Pavel
Published: October 2012

A new family of Lewis basic 2‐pyridyl oxazolines is developed and studied in the title reactions.
ChemInform Abstract: α‐Amination of Keto‐nitrones via Multihetero‐Cope Rearrangement Employing an Imidoyl Chloride Reagent.
Authors: Malinowski Justin T. , Malow Ericka J. , Johnson Jefrey S.
Published: October 2012

The condensation of nitronates (I) with imidoyl chloride (II) followed by a [3,3]‐rearrangement affords desired carbamates (III).
ChemInform Abstract: Concise, Aromatization‐Based Approach to an Elaborate C2‐Symmetric Pyrenophane.
Authors: Nandaluru Penchal Reddy , Dongare Prateek , Kraml Christina M. , Pascal Robert A. Jr. , Dawe Louise N. , Thompson David W. , Bodwell Graham J.
Published: October 2012

Two successive intramolecular McMurry reactions of tetraaldehyde (V) and a subsequent valence isomerization/dehydrogenation reaction afford the desired [12](1,6)pyrenophane derivative (VI) in low yield.