bluuebunny/crossref_metadata_2025 huggingface dataset:
Chiral Separation of Racemic Naproxen by High-Performance Liquid Chromatography with β-CD/SiO2 as the Chiral Stationary Phase
Authors: Wang Lili , Deng Jian , Ji Xuezhen , Liu Wanbin , Liang Jun , Yan Xiaona , Chen Dan , Xie Jie
Published: February 2014

A novel derivative β-cyclodextrin (β-CD) bonded silica gel (β-CD/SiO2) was prepared via carbodiimide activation and used as a chiral stationary phase (CSP). The β-CD/SiO2 CSP was characterizedby X-ray photoelectron spectroscopy and FTIR spectroscopy to prove the successful immobilization of β-CD onto the surface of the silica gel.The thermal behavior of the CSP was studied by differential scanning calorimetry and then used forthe chiral separation of racemic naproxen using HPLC. Several factors affecting the separation efficiency of naproxen enantiomers were investigatedsystematically. The following parameters were selected: methanol–0.01 M phosphate buffer solution (85 + 15, v/v, pH 3.5) was the mobile phase, the flow rate was 1.0 mL/min, and the column temperature was 35°C. Under optimal conditions, the racemic naproxen was efficiently separated with a resolution factor (RS) of 1.70 and a separation factor (α) of 1.25. This method was successfully used for the enantiomeric separation and purity assessment of naproxen in commercial naproxen sustained release tablets.
Development and Validation of an Alternative to Conventional Pretreatment Methods for Residue Analysis of Butachlor in Water, Soil, and Rice
Authors: Xue Jiaying , Jiang Wenqing , Liu Fengmao , Zhao Huiyu , Wang Suli , Peng Wei
Published: February 2014

A rapid and effective alternative analytical method for residues of butachlor in water, soil, and rice was established. The operating variables affecting performance of this method, including different extraction conditions and cleanup adsorbents, were evaluated. The determination of butachlor residues in soil, straw, rice hull, andhuskedrice was performed using GC/MS after extraction with n-hexane and cleanup with graphite carbon black. The average recoveries ranged from 81.5 to 102.7%, with RSDs of 0.6–7.7% for all of the matrixes investigated. The limits of quantitation were 0.05 mg/kg in water and rice plant, and 0.01 mg/kg in soil, straw, rice hull, and husked rice. A comparison among this proposed method, the conventional liquid–liquid extraction, the Quick, Easy, Cheap, Effective, Rugged, and Safe method, and Soxhlet extraction indicated that this method was more suitable for analyzing butachlor in rice samples. The further validation of the proposed method was carried out by Soxhlet extraction for the determination of butachlor residues in the husked rice samples, and the residue results showed there was no obvious difference obtained from these two methods. Samples from a rice field were found to contain butachlor residues below the maximum residue limits set by China (0.5 mg/kg) and Japan (0.1 mg/kg). The proposed method has a strong potential for application in routine screening and processing of largenumbers of samples. This study developed a more effective alternative to the conventional analytical methods for analyzing butachlor residues in various matrixes.
Determination of Nickel in Water, Food, and Biological Samples by Electrothermal Atomic Absorption Spectrometry After Preconcentration on Modified Carbon Nanotubes
Authors: Taher Mohammad Ali , Mazaheri Lida , Ashkenani Hamid , Mohadesi Alireza , Afzali Daryoush
Published: February 2014

A new and sensitive SPE method using modified carbon nanotubes for extraction and preconcentration, and electrothermal atomic absorption spectrometric determination of nickel (Ni) in real samples at ng/L levels was investigated. First, multiwalled carbon nanotubes were oxidized with concentrated HNO3, then modified with 2-(5-bormo-2-pyridylazo)-5-diethylaminophenol reagent. The adsorption was achieved quantitatively on a modified carbon nanotubes column in a pH range of 6.5 to 8.5; the adsorbed Ni(II) ions were then desorbed by passing 5.0 mL of 1 M HNO3. The effects of analytical parameters, including pHof the solution, eluent type and volume, samplevolume, flow rate of the eluent, and matrix ions, were investigated for optimization of the presented procedure. The enrichment factor was 180, and the LOD for Ni was 4.9 ng/L. The method was applied to the determination of Ni in water, food, and biological samples, and reproducible results wereobtained.
Detection and Identification of Transgenic Elements by Fluorescent-PCR-Based Capillary Gel Electrophoresis in Genetically Modified Cotton and Soybean
Authors: Basak Sanjay , Ehtesham Nasreen Z , Sesikeran Boindala , Ghosh Sudip
Published: February 2014

A detection method for genetically modified foods is an essential regulatory requirement for many countries. The present study is aimed at developing a qualitative method for detection of genetically modified organisms by combining PCR methodology with capillary gel electrophoresis (PCR-CGE) in a sequencing platform to detect Bacillus thuringiensis (Bt)-cotton (MON 531)and Roundup Ready (RR) soybean (GTS 40-3-2). A sensitive duplex PCR-CGE method was developed in which target DNA sequences (35S and Nos) were separated both by size and color to detect 0.01% Cry1Ac DNA (w/w) in Bt-cotton. A multiplex PCR-CGE method was developed to simultaneously detect fourtargets such as Sad1, Cry1Ac, 35S, and Nos in Bt-cotton. Four novel PCR primers were designed to customize amplicon size for multiplexing for better visualizationof multiple peaks. The LOD for Cry1Ac DNA specific PCR was 0.01% for Bt-cotton. The LOD for multiplex PCR assay was 0.05% for Bt-cotton. A singleplex PCR-CGE method was developed to detect Lec, 35S and Nos in a trace sample of RR soybean grainpowder (0.1%, w/w). This study demonstrates aPCR-CGE-based method for the qualitative detection of35S, Nos and Cry1Ac targets associated with genetically modifiedproducts.
Chemometric Classification Techniques as a Tool for Solving Problems in Analytical Chemistry
Authors: Bevilacqua Marta , Nescatelli Riccardo , Bucci Remo , Magrì Andrea D , Magrì Antonio L , Marini Federico
Published: February 2014

Supervised pattern recognition (classification) techniques, i.e., the family of chemometric methods whose aim is the prediction of a qualitative responseon a set of samples, represent a very important assortment of tools for solving problems in several areas of applied analytical chemistry. This paper describes the theory behind the chemometric classificationtechniques most frequently used inanalytical chemistry together with some examples of their application to real-world problems.
Clustering in Analytical Chemistry
Authors: Drab Klaudia , Daszykowski Michal
Published: February 2014

Data clustering plays an important role in the exploratory analysis of analytical data, and the use of clustering methods has been acknowledged in different fields of science. In this paper, principles of data clustering are presented with a direct focus onclustering of analytical data. The role of the clustering process in the analytical workflow is underlined, and its potential impact on the analytical workflow is emphasized.
Experimental Design in Analytical Chemistry—Part I: Theory
Authors: Ebrahimi-Najafabadi Heshmatollah , Leardi Riccardo , Jalali-Heravi Mehdi
Published: February 2014

This paper reviews the main concepts of experimental design applicable to the optimization of analytical chemistry techniques. The critical steps and tools for screening, including Plackett-Burman, factorial and fractional factorial designs, and response surface methodology such as central composite, Box-Behnken, and Doehlert designs, are discussed. Some useful routines are also presented for performing the procedures.
SIMPLIFICATION IN THE BRITISH PRESS: BINARY OPPOSITIONS IN CRIME REPORTS
Authors: Jančaříková Renata
Published: February 2014

This paper explores crime reports on verdicts and sentences in child/teenager murder cases in the British press with a view to demonstrating that ‘simplifi cation’ is one of the signifi cant values of crime reporting, regardless of the type of newspaper (Jewkes 2004). The analysis illustrates how both quality and popular British newspapers employ ‘binary oppositions’ (i.e. a typical feature of simplifi cation), such as good vs. evil, in order to communicate to their audiences the social status of victims and killers and at the same time traditional social values and norms. The employment of ‘binary oppositions’ in noun phrases that introduce and/or classify victims and killers thus enables newspapers to appeal to the public and act, or at least try to act, as moral guardians.
LEGAL DISCOURSE, POWER AND PRAGMATICS
Authors: Gyuró Monika
Published: February 2014

This paper explores crime reports on verdicts and sentences in child/teenager murder cases in the British press with a view to demonstrating that ‘simplifi cation’ is one of the signifi cant values of crime reporting, regardless of the type of newspaper (Jewkes 2004). The analysis illustrates how both quality and popular British newspapers employ ‘binary oppositions’ (i.e. a typical feature of simplifi cation), such as good vs. evil, in order to communicate to their audiences the social status of victims and killers and at the same time traditional social values and norms. The employment of ‘binary oppositions’ in noun phrases that introduce and/or classify victims and killers thus enables newspapers to appeal to the public and act, or at least try to act, as moral guardians.
Squamoid Cyst of Pancreatic Ducts: A Case Series Describing Novel Immunohistochemistry, Cytology, and Quantitative Cyst Fluid Chemistry
Authors: Hanson Joshua Anspach , Salem Ronald R. , Mitchell Kisha Anne
Published: January 2014

Squamoid cyst of pancreatic ducts (SCPD) is a benign pancreatic cyst often misdiagnosed preoperatively as a mucinous cyst. The histopathologic features are well described but the cytology and quantitative fluid chemistry profiles from fine-needle aspiration have not been reported. This case series discusses the cytology and cyst fluid chemistry profiles in 2 SCPDs and describes morphologic and immunohistochemical features that have not been previously reported. Fine-needle aspiration of 2 SCPDs yielded acellular debris lacking mucin or exfoliated squamous cells. Two cysts had elevated fluid carcinoembryonic antigen (CEA) and amylase levels. Positive immunohistochemical staining included cytokeratin 5/6, pCEA, synaptophysin, and chromogranin (both focal). MUC2 and MUC5AC showed negativity in all cases, while PAX8 showed negative nuclear staining. An accurate preoperative diagnosis of SCPD is potentially difficult in the setting of elevated fluid CEA levels, and acellular cytology as a mucinous cyst cannot be confidently excluded.
Reevaluating Significance of Perineural Invasion in Gastric Cancer Based on Double Immunohistochemical Staining
Authors: Zhou Zhi-Hua , Xu Gui-Fang , Zhang Wei-Jie , Zhao Hai-Bin , Wu Yao-Yi
Published: January 2014

Context.—In gastric cancer, the significance of perineural invasion remains controversial. Detecting perineural invasion with hematoxylin-eosin staining often leads to misdiagnosis. Labeling nerves by immunohistochemistry greatly assists perineural invasion detection, but it might also be misdiagnosed, because scattered cancer cells are difficult to recognize.

Objective.—To reevaluate the significance of perineural invasion in gastric cancer by double immunohistochemical staining that labels both nerves and cancer cells, and to examine agreements on perineural invasion detection between double immunohistochemical staining and single immunochemical staining (to label nerves) or hematoxylin-eosin staining.

Design.—We evaluated perineural invasion in 160 cases of gastric cancer with double immunohistochemical staining, single immunochemical staining, and hematoxylin-eosin staining, respectively; then we investigated the prognostic significance of perineural invasion.

Results.—Perineural invasion was detected in 65.0% (104 of 160), 38.1% (61 of 160), and 56.9% (91 of 160) of cases with double immunohistochemical staining, hematoxylin-eosin staining, and single immunohistochemical staining, respectively. Agreement was low between double staining and hematoxylin-eosin staining (κ = .34), and most false reports occurred in diffuse gastric cancer. Agreement between single immunochemical staining and double staining was good (κ = .67), but it declined in diffuse gastric cancer (κ = .28). Perineural invasion was closely associated with other clinicopathologic variables. Although perineural invasion–positive patients had a worse outcome than perineural invasion–negative patients, it was not an independent prognostic factor (P = .11; hazard ratio, 0.637; 95% confidence interval, 0.366–1.110).

Conclusions.—Double immunohistochemical staining could improve accuracy of perineural invasion detection in gastric cancer, particularly in the diffuse type. Moreover, perineural invasion predicts a poor outcome in gastric cancer, but it cannot provide more information than traditional clinicopathologic variables.
A domain-analytic perspective on sexual health in LCSH and RVM
Authors: McTavish Jill
Published: February 2014

This paper analyses and compares the treatment of sexual health in Library of Congress Subject Headings (LCSH) and Répertoire de vedettes-matière de l’Université Laval (RVM) using three of Bowker and Star’s (1999) infrastructural inversion techniques: practical politics, convergence, and
resistance. Our findings reveal that neither LCSH nor RVM offer a holistic representation of sexual health (practical politics), that LCSH’s topical representation of sexual health limits access to relevant material (convergence), and that the enhancement of LCSH through user-added content could improve but not replace these systems (resistance).
An examination of interdisciplinary theory between cognitive categorization and knowledge organization
Authors: Loehrlein Aaron
Published: February 2014

This paper is a preliminary comparison of the theories used to represent concepts in the field of
knowledge organization with similar theories that are used in the field of cognitive categorization. Both disciplines employ the same general types of conceptual representations, such as features, dimensions, labels and relationships. Both disciplines are also concerned with how people use these representations to organize and retrieve information. However, cognitive categorization is generally concerned with internal conceptual representations (ICRs), which are maintained in memory, while knowledge organization is
generally concerned with external conceptual representations (ECRs), which are maintained outside of memory. This fundamental distinction has profound effects on how the representations are structured, accessed and maintained. This paper explores these differences and points out cases in which ICRs and ECRs may affect each other. This analysis will support future research that utilizes ICRs in the study and evaluation of ECRs.
Prototype theory: An alternative concept theory for categorizing sex and gender?
Authors: Fox Melodie J.
Published: February 2014

Classical theories of classification and concepts, originating in ancient Greek logic, have been criticized by classificationists, feminists, and scholars of marginalized groups because of the rigidity of conceptual boundaries and hierarchical structure. Despite this criticism, the principles of classical theory still underlie major library classification schemes. Rosch’s prototype theory, originating from cognitive psychology, uses Wittgenstein’s “family resemblance” as a basis for conceptual definition. Rather than requiring all necessary and sufficient conditions, prototype theory requires possession of some but not all common qualities for membership in a category. This paper explores prototype theory to determine whether it captures the fluidity of gender to avoid essentialism and accommodate transgender and queer identities. Ultimately, prototype theory constitutes a desirable conceptual framework for gender because it permits commonality without essentialism, difference without eliminating similarity. However, the instability of prototypical definitions would be difficult to implement in a practical environment and could still be manipulated to subordinate. Therefore, at best, prototype theory could complement more stable concept theories by incorporating contextual difference.
Concretes, countries, and processes in Julius O. Kaiser's Theory of Systematic Indexing: A case study in the definition of general categories
Authors: Dousa Thomas M.
Published: February 2014

Although general categories are an important feature of many KOSs, they are difficult to define. If we are to understand the factors that render category definition difficult, we should consider how designers of past KOSs have defined the categories in their systems. This paper presents, as a case study, an analysis of the formulation of categories in J. Kaiser’s theory of systematic indexing, which was designed for the indexing of commercial literature. Kaiser’s theory posited three categories: concretes, countries, and processes. Close examination of his writings reveals semantic tensions in the definition of each category. Concretes were defined both in general terms as things-in-the-world and in domain specific terms as commodities; Countries were defined as political units but included geographical regions that were not politically unified; and Processes were defined alternately as conditions of concretes or actions associated with them. Tensions also appear in the categorial scheme comprising these categories, of which there were dyadic (Concrete-Process) and triadic (Concrete-Country-Process), the former of which was grounded on a theoretical model and the latter, on pragmatic, domain-specific considerations. Kaiser’s attempts to harmonize these models by deriving countries from concretes faltered because of his narrow construal of concretes. The tensions in Kaiser’s definition of categories are due to semantic overdetermination, while those associated with his categorial scheme are ascribable to the general tension between theory and practice.
RDA and RDF: A discourse analysis of two standards of resource description
Authors: Campbell D. Grant
Published: February 2014

The World Wide Web Consortium’s Resource Description Framework (RDF) and the library community’s new cataloguing standard, Resource Description and Access (RDA), both profess to provide sophisticated and flexible means of describing resources for modern Web environments. But both have attracted scepticism from potential users, who argue that their supposed innovations are overrated. A comparison of the two standards using Michel Foucault’s theory of discourse formations suggests that while the two standards differ in their community contexts and their use of intermediaries, they are similar to each other in their commitment to consistent, rigorously-defined entities and relationships; this shared commitment sets them apart from Web 2.0 developments, and offers the potential for fruitful
collaboration.
The Networked Infrastructure of Fossil Capitalism: Implications of the New Pipeline Debates for Environmental Justice in Canada
Authors: Scott Dayna Nadine
Published: January 2014

A read of the critical geography literature on the concept of “networked infrastructures” generates two arguments in relation to the environmental justice implications of the new pipeline debates. First, the proposed coast-to-coast pipeline is likely to exacerbate existing environmental inequities in Canada. Conceiving of the crude oil in a pipeline as a material flow of commodified nature demonstrates that, at the end of the pipe, inputs of labour, technology and capital are required to convert the crude into useable forms of energy. This leads to a serious engagement with the communities at the ends of the proposed pipes. Here, I illustrate the type of analysis that is required with a preliminary examination of the expected environmental health impacts from increased refinery emissions in Sarnia, Montréal and Saint John. Second, the notion that pipelines, despite their vital effects, are fixed and durable installations of built infrastructure—lending a marked inertia to the routes they cement—produces intergenerational equity concerns in relation to fossil capitalism. These concerns are brought powerfully to the fore by activists under the banner of Idle No More. In fact, it is this growing indigenous resistance movement centered on lands and resources that best illustrates the obvious contradiction: the permanence of the pipelines on the landscape, once built, underscores the gravity of the choices we are weighing, just as the active resistance of indigenous people across the county reveals the inherent instability of the networked infrastructure.
Commentary on Part 3: International political and economic structures
Authors: Farrelly Colin
Published: January 2014

Mathias Risse’s On Global Justice is a unique and important contribution to the growing literature on global justice. Risse’s approach to a variety of topics, ranging from domestic justice and common ownership of the earth, to immigration, human rights, climate change, and labour rights, is one that conceives of global justice as a philosophical problem. In this commentary I focus on a number of reservations I have about approaching global justice as a philosophical rather than an inherently practical problem. To his credit Risse does acknowledge at various stages of the book that a good deal of the applied terrain he ventures into presupposes complex and contentious empirical assumptions. A greater emphasis on those points would, I believe, helpfully reveal the shortcomings of tackling intellectual property rights by appealing to Hugo Grotius’s stance on the ownership of seas, or the shortcomings of tackling health by invoking the language of human rights without acknowledging and addressing the constraints and challenges of promoting health in an aging world.
Pluralist Internationalism in our Time
Authors: Chung1 Ryoa
Published: January 2014

In his 2012 book On Global Justice, Mathias Risse makes an invaluable contribution to the literature on theories of global justice. In this paper, I offer a critique of the fourth and final part of the book, entitled “Global Justice and Institutions,” which deals with the standing of the state within the pluralist internationalism defended by the author. My focus here is on the justification of the state system and the discussion on utopian ideals. I agree with Risse that the state remains the inescapable political structure that any serious theory of global justice must internalize within its conceptual framework. However, I differ from Risse’s approach in that I place greater emphasis on the historical contingency of the state system, including how prescriptions of global justice reflect historical contingencies stemming from globalization. From this point of view, pluralist internationalism should then be understood as a conceptual paradigm that mirrors its own historical contingency as embedded in our current world order. This recognition of the historical contingency of the state system serves two important purposes. One, it is a bulwark against any tendency to discredit too quickly the philosophical and practical relevance of ideal theory. Two, it buttresses the stance that we might still have the moral duty to pursue the goal of global justice beyond pluralist internationalism.
Special Relationships, Motivation and the Pursuit of Global Egalitarianism
Authors: Lenard Patti Tamara
Published: January 2014

One of the most significant challenges facing global egalitarian theorists is the motivational gap: there is a noted gap between the duties imposed by a global commitment to the equal moral worth of all people and the willingness of the wealthy to carry out these duties. For Pablo Gilabert, the apparent absence of motivation to act justly on a global scale presses us to consider the importance of feasibility in developing a persuasive account of global justice, part of which requires being attentive to what motivates us to act in support of global egalitarianism. In this article, I am critical of Gilabert’s account of the role that relationships between individuals play in conceiving our global justice duties. I begin with an account of some confusion in Gilabert’s account of the actual costs likely to be imposed on citizens of wealthy states as a result of the duties he demands of us and why it is important to resolve that confusion. I will then consider, and critique, Gilabert’s account of special responsibilities. I shall argue that, fundamentally, there is an ineliminable tension between the special responsibilities individuals legitimately possess and the duties they have to eradicate global poverty.
Au-free low temperature ohmic contacts for AlGaN/GaN power devices on 200 mm Si substrates
Authors: Firrincieli Andrea , De Jaeger Brice , You Shuzhen , Wellekens Dirk , Van Hove Marleen , Decoutere Stefaan
Published: February 2014

We report on the fabrication and characterization of Au-free Ti/Al/TiN-based ohmic contacts on 200 mm AlGaN/GaN epilayers for power devices. Materials and processing used are fully compatible for integration of GaN-based devices in a Si platform. Contact resistance values as low as 0.62 Ω·mm were measured for an optimum alloy temperature as low as 550 °C.
What is responsible for the strong observed asymmetry in teleconnections between El Niño and La Niña?
Authors: Zhang Tao , Perlwitz Judith , Hoerling Martin P.
Published: January 2014

A large asymmetric component (El Niño + La Niña) of El Niño–Southern Oscillation (ENSO)‐related teleconnections over North America is found during 1984–2009 that is comparable in strength to the commonly studied symmetric component (El Niño − La Niña). Climate reforecasts spanning this period are diagnosed in order to understand the processes responsible for the observed asymmetry. It is confirmed that an asymmetric component is indeed a fundamental property of atmospheric responses to recent ENSO forcing. Each and every composite of a 16‐member reforecast ensemble has appreciable asymmetry in tropical Pacific rainfall, upper tropospheric Pacific‐North American circulation patterns, and contiguous U.S. surface temperatures. There is considerable sampling variability in the magnitude of this asymmetric component among individual reforecast composites. We argue therefore that the true sea surface temperature boundary‐forced signal of ENSO teleconnections is likely composed of a symmetric component having greater magnitude than its asymmetric component, though the latter is an important property of how ENSO affects North American climate.
An efficient tracer test for time‐variable transit time distributions in periodic hydrodynamic systems
Authors: Harman Ciaran J. , Kim Minseok
Published: January 2014

The time‐varying transport dynamics of complex hydrodynamic systems with long transit times are difficult to observe due to the need for multiple tracer injections. Where only one or two distinct tracers are available, overprinting in the output concentrations limits the injection frequency. In this letter we propose an experimental method (the Periodic Tracer Hierarchy) that allows overprinted breakthrough curves to be decomposed into contributions from multiple injections of the same tracer, so long as the transporting flow is periodic. This method allows the time‐varying transit time distributions to be observed efficiently while making no a priori assumptions about the transport processes operating in the system. Simulations of transport through a soil column subject to a periodic sequence of irrigation events demonstrate that the distinct transit time distributions associated with each irrigation event can be retrieved almost exactly.
Electron energization and transport in the magnetotail during substorms
Authors: Pan Qingjiang , Ashour‐Abdalla Maha , Walker Raymond J. , El‐Alaoui Mostafa
Published: January 2014

It has been suggested recently that electrons are accelerated both near the reconnection site and during subsequent earthward transport. We provide global and quantitative evidence for this two‐step process by examining electron energization during a substorm event that occurred on 11 March 2008, when the Earth's magnetosphere was immersed in southward interplanetary magnetic field and high‐speed solar wind. The approach is to integrate coordinated measurements by Time History of Events and Macroscale Interactions during Substorms (THEMIS), global magnetohydrodynamic (MHD) modeling of the magnetosphere driven by upstream solar wind conditions, and large‐scale kinetics (LSK) simulation. In this event, THEMIS P2 at XGSM ~ − 15 RE detected a dipolarization pulse‐like magnetic structure coupled with energetic electron flux increase. About 1 min later, P3 and P4 at XGSM ~ − 10 RE observed dipolarized magnetic field and even larger flux increase. These multipoint data are applied to benchmark the MHD/LSK simulation. We quantify electron energization near the reconnection site and during earthward transport. We show that electrons were initially energized near the reconnection site, and subsequently further adiabatically accelerated far away from the reconnection site as the dipolarization front formed and grew. The adiabatic enhancement was rather effective given steep source electron distribution as a function of energy. In the outer magnetosphere with strong flows, E × B drift statistically dominated electron guiding center motion; thus, electrons were transported along the flow channel with small spatial diffusion. Close to the Earth, gradient and curvature drifts became appreciable; therefore, electrons circled around the region of large magnetic field.
Variability in surface meteorology and air‐sea fluxes due to cumulus convective systems observed during CINDY/DYNAMO
Authors: Yokoi Satoru , Katsumata Masaki , Yoneyama Kunio
Published: January 2014

This study examines the variability in surface meteorological parameters and air‐sea heat fluxes due to cold pools emanating from cumulus convective systems observed over the tropical Indian Ocean in November 2011. In particular, this study focuses on convective systems that are spatially smaller than mesoscale convective systems in a southeasterly trade wind environment. Composite analyses of convectively active periods show an increase in the sensible heat flux by 15–20 W m−2 that is primarily attributed to an increase in the difference between the surface air temperature and sea surface temperature and an increase in the latent heat flux by 30–70 W m−2 due to enhanced surface wind speeds. A succession of convectively active periods leads to a greater influence than those occurring independently. The direction of the surface wind velocity anomaly due to cold pools tends to be close to that of the environmental wind velocity, resulting in an efficient enhancement of wind speed. This study also demonstrates the close relation between cold pool intensities and convective activity. In particular, two measures of cold pool intensity, a minimum surface air temperature and a maximum amount of surface wind speed enhancement, are correlated with each other and with the convective activity around the observation point measured by radar‐estimated rainfall and radar echo coverage.
Cluster observations of fast magnetosonic waves in the heliosphere current sheet
Authors: Dai Lei , Wygant John R. , Cattell Cynthia A. , Thaller Scott , Kersten Kris , Breneman Aaron , Tang Xiangwei
Published: January 2014

We present Cluster spacecraft observations of large‐amplitude (δ|B|/|B|∼1) fast‐mode magnetosonic waves in the heliospheric current sheet (HCS). The crossings of the HCS and the associated heliospheric plasma sheet (HPS) are encountered by Cluster in the near‐Earth solar wind and by ACE upstream of Earth. Multiple current layers are detected in correspondence with small‐scale discontinuities in the regime of open magnetic field lines within the HCS. Fast magnetosonic waves are observed at one current layer, accompanying the phase‐steeped edge of a large‐amplitude transverse Alfvén wave. The observed fast‐mode waves are in the frequency range 0.01 Hz–0.2 Hz, characterized by a strong correlation between variations of plasma density and magnetic field strength. Analysis of ratio δE/δBindicate that the fast‐mode wave packet consists of an antisunward propagating component and a larger sunward propagating component in the rest frame of the solar wind. The fast‐mode waves are not observed by ACE in the upstream solar wind. The generation of the fast‐mode waves may relate to the development of the phase‐steeped Alfvén wave and has profound effects on the evolution of the solar wind plasma.
An Optical Sensor for Volatile Amines Based on an Inkjet‐Printed, Hydrogen‐Bonded, Cholesteric Liquid Crystalline Film
Authors: Stumpel Jelle E. , Wouters Claudia , Herzer Nicole , Ziegler Judith , Broer Dirk J. , Bastiaansen Cees W. M. , Schenning Albertus P. H. J.
Published: January 2014

A printable hydrogen‐bonded cholesteric liquid crystal (CLC) polymer film is described, which can be used as a sensor for detection of gaseous trimethylamine (TMA). In this optical sensor the virgin CLC polymer network reflects green light. When anhydrous TMA gas penetrates the film, disruption of the hydrogen bonds occurs, with the simultaneous formation of carboxylate salts. The consequent reduction of the molecular order causes the green reflecting CLC film to become colorless. However, exposure to TMA in water‐saturated nitrogen gas results in a red reflecting film. Due to the hygroscopic nature of the polymer salt that is formed by TMA, water vapor which is present in the environment is absorbed by the films. This leads to swelling of the film, resulting in an increase in pitch size and therefore a red shift of the reflection band. Interestingly, after exposure to ambient conditions, restoration of the green reflecting film takes place, showing that the sensor can be used multiple times. In a proof of principle experiment, it was shown that these CLC films can be used as optical sensors to detect volatile amines, that are produced by decaying fish.
Birth month associations with height, head circumference, and limb lengths among peruvian children
Authors: Pomeroy Emma , Wells Jonathan C.K. , Stanojevic Sanja , Miranda J. Jaime , Cole Tim J. , Stock Jay T.
Published: January 2014

Associations between season of birth and body size, morbidity, and mortality have been widely documented, but it is unclear whether different parts of the body are differentially sensitive, and if such effects persist through childhood. This may be relevant to understanding the relationship between early life environment and body size and proportions. We investigated associations between birth month and anthropometry among rural highland (n = 162) and urban lowland (n = 184) Peruvian children aged 6 months to 8 years. Stature; head‐trunk height; total limb, ulna, tibia, hand, and foot lengths; head circumference; and limb measurements relative to head‐trunk height were converted to internal age‐sex‐specific z scores. Lowland and highland datasets were then analyzed separately for birth month trends using cosinor analysis, as urban conditions likely provide a more consistent environment compared with anticipated seasonal variation in the rural highlands. Among highland children birth month associations were significant most strongly for tibia length, followed by total lower limb length and stature, with a peak among November births. Results were not significant for other measurements or among lowland children. The results suggest a prenatal or early postnatal environmental effect on growth that is more marked in limb lengths than trunk length or head size, and persists across the age range studied. We suggest that the results may reflect seasonal variation in maternal nutrition in the rural highlands, but other hypotheses such as variation in maternal vitamin D levels cannot be excluded. Am J Phys Anthropol 154:115–124, 2014. © 2014 The Authors. American Journal of Physical Anthropology Published by Wiley Periodicals, Inc.
Aktivierung von Schwefelhexafluorid an hoch reduzierten niedrig koordinierten Nickel‐Distickstoff‐Komplexen
Authors: Holze Patrick , Horn Bettina , Limberg Christian , Matlachowski Corinna , Mebs Stefan
Published: January 2014

Das Klimagas Schwefelhexafluorid ist in der Literatur ein viel verwendetes Standardbeispiel für ein sehr reaktionsträges anorganisches Molekül, das selbst durch Disauerstoff in einer elektrischen Entladung nicht angegriffen wird. Dennoch sind reduzierte β‐Diketiminato‐Nickel‐Komplexe unter Standardbedingungen in der Lage, SF6 in Fluorido‐ und Sulfido‐Verbindungen zu überführen. Das Fluorido‐Produkt besitzt dabei eine präzedenzlose [NiF]+‐Einheit, bei der das Nickelatom nur dreifach koordiniert ist. Der Sulfido‐Komplex beinhaltet eine seltene nahezu lineare [Ni(μ‐S)Ni]2+‐Anordnung. Die Reaktion wurde mittels 1H‐NMR‐, IR‐ und ESR‐spektroskopischen Methoden untersucht. Diese führten zur Identifizierung einer Zwischenstufe und gewährten so einen Einblick in den Mechanismus der 8‐Elektronen‐Reduktion von SF6 .
Rapid Synthesis of Fused N‐Heterocycles by Transition‐Metal‐Free Electrophilic Amination of Arene CH Bonds
Authors: Gao Hongyin , Xu Qing‐Long , Yousufuddin Muhammed , Ess Daniel H. , Kürti László
Published: January 2014

We disclose an efficient and operationally simple protocol for the preparation of fused N‐heterocycles starting from readily available 2‐nitrobiaryls and PhMgBr under mild conditions. More than two dozen N‐heterocycles, including two bioactive natural products, have been synthesized using this method. A stepwise electrophilic aromatic cyclization mechanism was proposed by DFT calculations.
Structure‐Based Approach To Improve a Small‐Molecule Inhibitor by the Use of a Competitive Peptide Ligand
Authors: Ono Katsuki , Takeuchi Koh , Ueda Hiroshi , Morita Yasuhiro , Tanimura Ryuji , Shimada Ichio , Takahashi Hideo
Published: January 2014

Structural information about the target–compound complex is invaluable in the early stage of drug discovery. In particular, it is important to know into which part of the initial compound additional interaction sites could be introduced to improve its affinity. Herein, we demonstrate that the affinity of a small‐molecule inhibitor for its target protein could be successfully improved by the constructive introduction of the interaction mode of a competitive peptide. The strategy involved the discrimination of overlapping and non‐overlapping peptide–compound pharmacophores by the use of a ligand‐based NMR spectroscopic approach, INPHARMA. The obtained results enabled the design of a new compound with improved affinity for the platelet receptor glycoprotein VI (GPVI). The approach proposed herein efficiently combines the advantages of compounds and peptides for the development of higher‐affinity druglike ligands.
Mixed IR/Vis Two‐Dimensional Spectroscopy: Chemical Exchange beyond the Vibrational Lifetime and Sub‐ensemble Selective Photochemistry
Authors: van Wilderen Luuk J. G. W. , Messmer Andreas T. , Bredenbeck Jens
Published: January 2014

Two‐dimensional exchange spectroscopy (2D EXSY) is a powerful method to study the interconversion (chemical exchange) of molecular species in equilibrium. This method has recently been realized in femtosecond 2D‐IR spectroscopy, dramatically increasing the time resolution. However, current implementations allow the EXSY signal (and therefore the chemical process of interest) only to be tracked during the lifetime (T1) of the observed spectroscopic transition. This is a severe limitation, as typical vibrational T1 are only a few ps. An IR/Vis pulse sequence is presented that overcomes this limit and makes the EXSY signal independent of T1. The same pulse sequence allows to collect time‐resolved IR spectra after electronic excitation of a particular chemical species in a mixture of species with strongly overlapping UV/Vis spectra. Different photoreaction pathways and dynamics of coexisting isomers or of species involved in different intermolecular interactions can thus be revealed, even if the species cannot be isolated because they are in rapid equilibrium.
Experimental Charge Density Study of a Silylone
Authors: Niepötter Benedikt , Herbst‐Irmer Regine , Kratzert Daniel , Samuel Prinson P. , Mondal Kartik Chandra , Roesky Herbert W. , Jerabek Paul , Frenking Gernot , Stalke Dietmar
Published: January 2014

An experimental and theoretical charge density study confirms the interpretation of (cAAC)2Si as a silylone to be valid. Two separated VSCCs present in the non‐bonding region of the central silicon are indicative for two lone pairs. In the experiment, both the two crystallographically independent SiC bond lengths and ellipticities vary notably. It is only the cyclohexyl derivative that shows significant differences in these values, both in the silylones and the germylones. Only by calculating increasing spheres of surrounding point charges we were able to recover the changes in the properties of the charge density distribution caused by weak intermolecular interactions. The nitrogen–carbene‐carbon bond seems to have a significant double‐bond character, indicating a singlet state for the carbene carbon, which is needed for donor acceptor bonding. Thus the sum of bond angles at the nitrogen atoms seems to be a reasonable estimate for singlet versus triplet state of cAACs.
Rhodium(II)‐Catalyzed Nondirected Oxidative Alkenylation of Arenes: Arene Loading at One Equivalent
Authors: Vora Harit U. , Silvestri Anthony P. , Engelin Casper J. , Yu Jin‐Quan
Published: January 2014

A bimetallic RhII catalyst promoted the CH alkenylation of simple arenes at 1.0 equivalent without the use of a directing group. A phosphine ligand as well as cooperative reoxidation of RhII with Cu(TFA)2 and V2O5 proved essential in providing monoalkenylated products in good yields and selectivities, especially with di‐ and trisubstituted arenes.
Ring‐opening polymerization of cyclic esters by pincer complexes derived from alkaline earth metals
Authors: Lamberti Marina , Botta Antonella , Mazzeo Mina
Published: January 2014

We report the synthesis and characterization of new Ca(II) and Mg(II) complexes of the type [Ph―PPP]MR (M = Ca, R = N(SiMe3)2 (1); M = Mg, R = nBu (2)) where Ph―PPP− is a tridentate monoanionic ligand (Ph―PPP―H = bis(2‐diphenylphosphinophenyl)phosphine). Reaction of the opportune metal precursor (Ca[N(SiMe3)2]2.THF2 or MgnBu2) with 1 equiv. of the pro‐ligand Ph―PPP―H produces the corresponding calcium amido (1) or magnesium butyl (2) complex in high yield. Solution NMR studies show monomeric and kinetically stable structures for both species. The obtained complexes efficiently mediate the ring‐opening polymerization of ɛ‐caprolactone showing a turnover frequency of 40 000 h−1. In the presence of a hexogen alcohol, up to 2000 equiv. of monomer are converted by using a low loading of catalyst (5 µmol). Kinetic studies show a first‐order reaction in monomer concentration. Copyright © 2014 John Wiley & Sons, Ltd.
Photocatalytic hydrogen evolution by two comparable [FeFe]‐hydrogenase mimics assembled to the surface of ZnS
Authors: Song Xiao‐Wei , Wen Hui‐Min , Ma Cheng‐Bing , Hu Ming‐Qiang , Chen Hui , Cui Hong‐Hua , Chen Chang‐Neng
Published: January 2014

Two photocatalytic hydrogen evolution systems were constructed by assembling [FeFe]‐hydrogenase mimics, either carboxyl group‐containing (C1) or not (C2), on to the surface of ZnS using triethanolamine as electron donor in DMF‐H2O (9/1, v/v) solution. Upon irradiation for 30 h, the turnover numbers of hydrogen evolution were 3400 and 4950 for the hybrid system C1/ZnS and C2/ZnS, respectively. The photocatalytic activity of the C2/ZnS system was five times higher than the activity of the pristine ZnS, suggesting that the [FeFe]‐hydrogenase mimics are crucial toward improving the activity of ZnS. On the basis of the spectroscopic studies and analyses, the photogenerated electron transfer from ZnS to the mimics is probably responsible for the activity enhancement of ZnS. The time dependence of hydrogen generation shows that the mimic C2 is more active than C1. The different hydrogen evolution activity can be attributed to the different adsorption modes of the two [FeFe]‐hydrogenase mimics on the surface of ZnS. Copyright © 2014 John Wiley & Sons, Ltd.
Antibacterial, flame retardant, and physico‐chemical properties of cotton fabric graft copolymerized with a binary mixture of acrylonitrile and 4‐vinylpyridine
Authors: Kaur Inderjeet , Bhati Pooja , Sharma Bharti
Published: January 2014

Modification of cotton fabric has been carried out through chemically induced graft copolymerization of binary mixture of acrylonitrile (AN) and 4‐vinyl pyridine (4‐VP) using ceric ammonium nitrate, (CAN) as initiator. Maximum percentage of grafting (151.28%) has been obtained at [4‐VP] = 0.376 mol L−1 and [AN] = 1.221 mol L−1, [CAN] = 0.0255 mol L−1 and [HNO3] = 0.9585 mol L−1 in 25mL of water at 70°C in 180 min. Post quarternization and phosphorylation reactions of the grey and grafted cotton fabrics have been carried out to study their antibacterial and flame retardant properties respectively. The fabrics have been characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). The physico‐chemical properties such as wettability, moisture regain, crease recovery and tensile strength of the grey and grafted cotton fabric have also been evaluated. The modified fabric has been shown to exhibit excellent antibacterial and flame retarding properties with improved physico‐chemical properties except for the mechanical properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40415.
Gelatin‐carbohydrate phase‐separated hydrogels as bioactive carriers in vaginal delivery: Preparation and physical characterizations
Authors: Singh Vinay Kumar , Sagiri Sai Sateesh , Pal Kunal , Khade Shankar M. , Pradhan Dillip K. , Bhattacharya Mrinal K.
Published: January 2014

The current study focuses on the alteration of properties of the gelatin hydrogels using polysaccharides (e.g., maltodextrin, dextran, and sodium carboxymethyl cellulose) for probable use in vaginal delivery of antimicrobials. The hydrogels were prepared by varying the proportions of gelatin and polysaccharides and were characterized by microscopy, mechanical testing, and impedance spectroscopy. Metronidazole (MZ), drug of choice for the treatment of bacterial vaginosis, was incorporated within the hydrogels. In vitro release studies of MZ from the hydrogels was studied in‐depth using modified Franz's diffusion cell. Antimicrobial efficiency of the MZ‐loaded hydrogels was tested against E. coli and B. subtilis. The results suggested that the incorporation of polysaccharides resulted in the phase‐separated hydrogels. The properties of the hydrogels was found be suitable for vaginal delivery. The drug release and antimicrobial efficiency from the hydrogels suggested that the developed hydrogels may be used for the delivery of antimicrobials in the vaginal lumen. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40445.