bluuebunny/crossref_metadata_2025_split huggingface dataset:
Star‐Shaped Quaternary Alkylammonium Polyhedral Oligomeric Silsesquioxane Ionic Liquids
Authors: Manickam Sundar , Cardiano Paola , Mineo Placido G. , Lo Schiavo Sandra 
Published: April 2014

AbstractNew star‐shaped quaternary ammonium (QA) polyhedral oligomeric silsesquioxane (POSS) salts based on octakis(tetraalkylammonium) POSS cations bearing alkyl chains of different length (methyl, n‐butyl, and n‐octyl) and differently polarizable anions [iodide, bis(trifluoromethylsulfonyl)imide, and ibuprofen] have been synthesized and characterized. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) investigations show that the nature of the cation plays a key role in determining the thermal behavior of QA POSS salts featuring the longest alkyl chains, whereas the influence exerted by anions becomes relevant for those bearing short and medium alkyl chains. All the QA POSS salts display amorphous behavior and, with the exception of octakis(trimethylpropylammonium)‐ and octakis(tri‐n‐butylpropylammonium)octasilsesquioxane iodide, may be classified as ionic liquids. Dynamic contact‐angle studies reveal their hydrophilic attitude owing to the preferential orientation of the tetraalkylammonium groups at the film–water interface.
Dual‐Layered Quasi‐Two‐Dimensional Organic Conductors with Presumable Incoherent Electron Transport
Authors: Lyubovskaya Rimma , Zhilyaeva Elena , Shilov Gena , Audouard Alain , Vignolles David , Canadell Enric , Pesotskii Sergei , Lyubovskii Rustem 
Published: April 2014

AbstractWe have prepared a series of BEDT‐TTF or BETS‐based radical‐cation salts (D)4MBr4(C6H6–nXn) with tetrahedral anions [MIIBr4]2– (D = BETS, BEDT‐TTF; X = F, Cl, Br; n = 1, 2). The salts (D)4MBr4(C6H6–nXn) are characterized by the different structures of neighboring conducting layers, structural phase transitions, and different types of conductivity, namely, metallic and semiconducting, along and across the conducting layers, respectively. The Fermi surface of the metallic layer of (D)4MBr4(C6H6–nXn) with alternating crystallographically different conducting layers (dual‐layered salts) provides a roadmap for interpreting the transport properties of quasi‐two‐dimensional organic conductors. This review reports on the structures of these compounds, the effect of MBr4 anions and solvent on the occurrence of phase transitions, different Fermi surface topologies in connection with the different structures of neighboring conducting layers, and the possibility of the incoherent transport of charge carriers in such systems.
BODIPY Fluorophore Toolkit for Probing Chemical Reactivity and for Tagging Reactive Functional Groups
Authors: Hensle Eva M. , Esfandiari N. Melody , Lim Sung‐Gon , Blum Suzanne A. 
Published: April 2014

AbstractThe photophysical and synthetic studies of new tether‐functionalized boron dipyrromethene (BODIPY) fluorophores as probes for chemical reactions are described. These compounds differ from typically reported probes in that they provide a way to tag and indicate chemical reactions without chemical transformation of the BODIPY core itself; instead the dyes are spectators. The introduction and modification of the tether has expanded the available chemistry and yet these new BODIPY derivatives have similar photophysical properties to their parent substrates. As a result of the chemistry enabled by these probes, a single step of a multistep metal‐catalyzed reaction was revealed by a change in the fluorescence resonance energy transfer (FRET) signal. The fundamental knowledge of quantum yield, FRET efficiencies, and reagent compatibility is critical to enabling the broader application of fluorescent probes to study chemical reaction mechanisms by cutting‐edge microscopy techniques.
Palladium‐Catalyzed Allenylation/Intramolecular Diels–Alder Reaction of Furans with Propargyl Carboxylates for the Synthesis of Polycyclic Compounds
Authors: Wang Chengyu , Kong Lingkai , Li Yanli , Li Yanzhong 
Published: April 2014

AbstractA highly efficient palladium‐catalyzed cascade reaction of propargyl carboxylates bearing a furanyl group with organoborons was developed. This methodology offers rapid access to polycyclic Diels–Alder cycloadducts in good to high yields. The thus‐formed oxygen‐bridged products were further converted into anthracene derivatives in a chemoselective manner under mild conditions.
Combined Ugi‐4CR/CuAAC Approach to Triazole‐Based Neoglycolipids
Authors: Pérez‐Labrada Karell , Brouard Ignacio , Méndez Inmaculada , Pérez Carlos S. , Gavín José A. , Rivera Daniel G. 
Published: April 2014

AbstractNew glycolipids that feature a carbohydrate/triazole/lipid hybrid architecture were readily produced by a combined multicomponent/click approach. The process comprises the use of the Ugi four‐component reaction to construct double‐lipidic scaffolds that have either alkyne or azide functionalities followed by conjugation to mono‐ and trisaccharides through a CuI‐catalyzed 1,3‐dipolar cycloaddition (click) process. The high chemical efficiency and feasibility of the overall procedure provides new opportunities for the rapid creation and biological screening of libraries of this unique class of Ugi/click glycolipids. Dynamic NMR experiments were performed to evaluate the free energy of activation related to the isomerization of the cis/trans amide bond in these compounds. This is the first time that such multicomponent and cycloaddition processes have been combined for the synthesis of glycolipids.
Enantioselective Organocatalytic Conjugate Addition of Alkenes to α,β‐Enones
Authors: Cui Lingyun , Zhang Long , Luo Sanzhong , Cheng Jin‐Pei 
Published: April 2014

AbstractWe report the first example of the enantioselective conjugate addition of alkenes (aromatic enamines) to enones catalyzed by chiral primary amines. The reactions encompass a plethora of α,β‐enones including difficult α‐substituted vinyl ketones to give vinylation adducts in high yields with good enantioselectivity. The methodology is of synthetic potential in accessing chiral functional materials.
The Implications of Disciplinary Literacy
Authors: Shanahan Cynthia , Shanahan Timothy 
Published: April 2014

AbstractDuring the past several years, middle schools and high schools have been shifting their attention to disciplinary literacy. The Common Core State Standards are explicit in requiring teachers to teach the literacy of science, literature, and history, and even states that are not part of Common Core (such as Texas) are making this shift as well. This e‐mail discussion between Cynthia and Timothy Shanahan explores the implications of disciplinary literacy for motivation, assessment, teacher education, and professional development.
Using Disciplinary Literacies to Enhance Adolescents' Engineering Design Activity
Authors: Wilson Amy Alexandra , Smith Emma , Householder Daniel L. 
Published: April 2014

AbstractThis comparative case study describes the literacy practices of two groups of adolescents as they sought to solve authentic problems through engineering design processes. Three types of data were collected as the groups addressed these problems: video‐ and audio‐recordings of their conversations; adolescent‐generated products; and pre‐ and post‐challenge interviews. The authors used existing coding schemes of engineering design activity to identify when the adolescents enacted different stages of engineering design, as well as a modified form of constant comparative analysis to identify the literacy practices that corresponded with each stage. The analysis indicates that applications of literacy practices at each stage of the engineering design process enhanced the adolescents' overall design activity, whereas the absence of literacy practices often impeded the viability of their final designs. The authors suggest implications for high school engineering and science teachers who seek to enhance their students' design activity through literacy instruction.
Character Journaling Through Social Networks
Authors: White John Wesley , Hungerford‐Kresser Holly 
Published: April 2014

AbstractCountering reactionary attempts to ban social media from schools is a strong research based rationale for bringing social media into the literacy classroom. When used as a medium to explore literature—or more specifically for interactive character journaling—this medium exemplifies how meaning is created by individuals' interactions with texts, by the prior knowledge they bring to their reading, and by the negotiation of meaning by participants in this digital “third space.” Used this way, social media can scaffold reading, promote critical discussions about texts, prompt basic sociohistorical research, and engage students in examining discourse, and provide an authentic venue for students to practice code‐switching. This study highlights that social media is anything but an educational distraction; rather, when used appropriately it can serve as an engaging and interactive foray into socially‐mediated literacy and constructivist learning.
The association of proton pump inhibitors and hypomagnesemia in the community setting
Authors: Markovits Noa , Loebstein Ronen , Halkin Hillel , Bialik Martin , Landes‐Westerman Janet , Lomnicky Joseph , Kurnik Daniel 
Published: April 2014

AbstractEvidence for the association between hypomagnesemia and proton pump inhibitors (PPIs), highlighted by the 2011 FDA Drug Safety Communication, rests mainly on studies in hospitalized patients. Our objectives were to determine the prevalence of hypomagnesemia and its association with PPIs in the community setting. We performed a retrospective cross‐sectional analysis of a large health maintenance organization administrative database, including ambulatory patients with ≥1 serum magnesium concentrations between 2008 and 2011, the lowest referred to as “index magnesium.” In cases with any (index magnesium ≤0.7 mmol/L) or severe (≤0.55 mmol/L) hypomagnesemia, we analyzed (vs. controls, >0.7 mmol/L) the association with PPI or H2‐blocker use during the 4–12 months preceding the index magnesium by logistic regression analysis, adjusting for confounders. Among 95,205 subjects, 5,696 (6.0%) had any hypomagnesemia, which was severe in 454 (0.5%), with twofold higher prevalences in those with established risk factors. PPI use during the 4 months preceding the index magnesium was more common in cases of any hypomagnesemia (adjusted OR = 1.66; 95% CI, 1.55–1.78) and severe hypomagnesemia (adjusted OR = 3.79; 2.99–4.82) than in controls without acid suppression. Hypomagnesemia remained significantly associated with PPI use when using H2‐blocker‐users as reference (adjusted OR = 1.25 [P = 0.003] and 2.65 [P < 0.001] for any and severe hypomagnesemia, respectively). We conclude that hypomagnesemia is associated with PPI use in ambulatory patients.
Age‐related differences in diffusion tensor indices and fiber architecture in the medial and lateral gastrocnemius
Authors: Sinha Usha , Csapo Robert , Malis Vadim , Xue Yanjie , Sinha Shantanu 
Published: April 2014

PurposeTo investigate age related changes in diffusion tensor indices and fiber architecture of the medial and lateral gastrocnemius (MG and LG) muscles using diffusion tensor imaging (DTI).Materials and MethodsThe lower leg of five young and five senior subjects was scanned at 3 Tesla and DTI indices extracted using three methods: region of interest, histogram, and tract based. Tracked fibers were automatically edited to ensure physiologically relevant tracks. Pennation angles were measured with respect to the deep and superficial aponeuroses of both muscles.ResultsThe three methods provided internally consistent measures of the DTI indices (correlation coefficient in the range of 0.90–0.99). The primary, secondary, and tertiary eigenvalues in the MG and LG increased significantly in the senior cohort (P < 0.05), while the small increase in fractional anisotropy with age was not significant (MG/LG: P = 0.39/0.85; 95% confidence interval: [−0.059/−0.056, 0.116/0.064]). Fiber lengths of MG fibers originating distally were significantly decreased in seniors (P < 0.05) while pennation angles decreased with age in the MG and LG but this was not significant.ConclusionFiber atrophy and increased fibrosis have opposing effects on the diffusion indices resulting in a complicated dependence with aging. Fiber architectural changes could play a role in determining aging muscle function. J. Magn. Reson. Imaging 2015;41:941–953. © 2014 Wiley Periodicals, Inc.
Protecting the radiation‐damaged skin from friction: a mini review
Authors: Herst Patries M. 
Published: April 2014

AbstractRadiation‐induced skin reactions are an unavoidable side effect of external beam radiation therapy, particularly in areas prone to friction and excess moisture such as the axilla, head and neck region, perineum and skin folds. Clinical studies investigating interventions for preventing or managing these reactions have largely focussed on formulations with moisturising, anti‐inflammatory, anti‐microbial and wound healing properties. However, none of these interventions has emerged as a consistent candidate for best practice. Much less emphasis has been placed on evaluating ways to protect the radiation‐damaged skin from friction and excess moisture. This mini review analyses the clinical evidence for barrier products that form a protective layer by adhering very closely to the skin folds and do not cause further trauma to the radiation‐damaged skin upon removal. A database search identified only two types of barrier products that fitted these criteria and these were tested in two case series and six controlled clinical trials. Friction protection was most effective when the interventions were used from the start of treatment and continued for several weeks after completion of treatment. Soft silicone dressings (Mepilex Lite and Mepitel Film) and Cavilon No Sting Barrier Film, but not Cavilon Moisturizing Barrier Cream, decreased skin reaction severity, most likely due to differences in formulation and skin build‐up properties. It seems that prophylactic use of friction protection of areas at risk could be a worthwhile addition to routine care of radiation‐damaged skin.
A survey of radiographers' confidence and self‐perceived accuracy in frontline image interpretation and their continuing educational preferences
Authors: Neep Michael J. , Steffens Tom , Owen Rebecca , McPhail Steven M. 
Published: April 2014

AbstractIntroductionThe provision of a written comment on traumatic abnormalities of the musculoskeletal system detected by radiographers can assist referrers and may improve patient management, but the practice has not been widely adopted outside the United Kingdom. The purpose of this study was to investigate Australian radiographers' perceptions of their readiness for practice in a radiographer commenting system and their educational preferences in relation to two different delivery formats of image interpretation education, intensive and non‐intensive.MethodsA cross‐sectional web‐based questionnaire was implemented between August and September 2012. Participants included radiographers with experience working in emergency settings at four Australian metropolitan hospitals. Conventional descriptive statistics, frequency histograms, and thematic analysis were undertaken. A Wilcoxon signed‐rank test examined whether a difference in preference ratings between intensive and non‐intensive education delivery was evident.ResultsThe questionnaire was completed by 73 radiographers (68% response rate). Radiographers reported higher confidence and self‐perceived accuracy to detect traumatic abnormalities than to describe traumatic abnormalities of the musculoskeletal system. Radiographers frequently reported high desirability ratings for both the intensive and the non‐intensive education delivery, no difference in desirability ratings for these two formats was evident (z = 1.66, P = 0.11).ConclusionsSome Australian radiographers perceive they are not ready to practise in a frontline radiographer commenting system. Overall, radiographers indicated mixed preferences for image interpretation education delivered via intensive and non‐intensive formats. Further research, preferably randomised trials, investigating the effectiveness of intensive and non‐intensive education formats of image interpretation education for radiographers is warranted.
Assessing health in agriculture – towards a common research framework for soils, plants, animals, humans and ecosystems
Authors: Vieweger Anja , Döring Thomas F 
Published: April 2014

AbstractIn agriculture and food systems, health‐related research includes a vast diversity of topics. Nutritional, toxicological, pharmacological, epidemiological, behavioural, sociological, economic and political methods are used to study health in the five domains of soils, plants, livestock, humans and ecosystems. An idea developed in the early founding days of organic agriculture stated that the health of all domains is one and indivisible. Here we show that recent research reveals the existence and complex nature of such health links among domains. However, studies of health aspects in agriculture are often separated by disciplinary boundaries. This restrains the understanding of health in agricultural systems. Therefore we explore the opportunities and limitations of bringing perspectives together from the different domains. We review current approaches to define and assess health in agricultural contexts, comparing the state of the art of commonly used approaches and bringing together the presently disconnected debates in soil science, plant science, veterinary science and human medicine. Based on a qualitative literature analysis, we suggest that many health criteria fall into two paradigms: (1) the Growth Paradigm, where terms are primarily oriented towards continued growth; (2) the Boundary Paradigm, where terms focus on maintaining or coming back to a status quo, recognising system boundaries. Scientific health assessments in agricultural and food systems need to be explicit in terms of their position on the continuum between Growth Paradigm and Boundary Paradigm. Finally, we identify areas and concepts for a future direction of health assessment and research in agricultural and food systems. © 2014 Society of Chemical Industry
Kinetics and Mechanism of Oxidation of l‐Histidine by Permanganate Ions in Sulfuric Acid Medium
Authors: FAWZY A. , ASHOUR S. S. , MUSLEH M. A. 
Published: April 2014

ABSTRACTThe reaction kinetics for the oxidation of l‐histidine by permanganate ions have been investigated spectrophotometrically in sulfuric acid medium at constant ionic strength and temperature. The order with respect to permanganate ions was found to be unity and second in acid concentration, whereas a fractional order is observed with respect to histidine. The reaction was observed to proceed through formation of a 1:1 intermediate complex between oxidant and substrate. The effect of the acid concentration suggests that the reaction is acid catalyzed. Increasing the ionic strength has no significant effect on the rate. The influence of temperature on the rate of reaction was studied. The presence of metal ion catalysts was found to accelerate the oxidation rate, and the order of effectiveness of the ions was Cu2+ > Ni2+ > Zn2+. The final oxidation products were identified as aldehyde (2‐imidazole acetaldehyde), ammonium ion, manganese(II), and carbon dioxide. Based on the kinetic results, a plausible reaction mechanism is proposed. The activation parameters were determined and discussed with respect to a slow reaction step.
Overcoming Cancer Multidrug Resistance by Codelivery of Doxorubicin and Verapamil with Hydrogel Nanoparticles
Authors: Qin Ming , Lee Yong‐Eun Koo , Ray Aniruddha , Kopelman Raoul 
Published: April 2014

AbstractThe efficacy of chemotherapy is often inhibited by multidrug resistance (MDR). A highly engineerable hydrogel nanoparticle (NP) serves as a carrier for the optimal codelivery to tumor cells of the chemodrug, doxorubicin (Dox) and the chemosensitizer, verapamil (Vera), aiming at alleviating tumor MDR. The hydrogel NPs are prepared via the copolymerization of acrylamide and 2‐carboxyethyl acrylate. Dox and Vera are post‐loaded into the respective NPs, with drug loading around 7.7 wt% and 8.0 wt%, respectively. The codelivery of Dox‐NPs and Vera‐NPs increases the intracellular accumulation of Dox, and significantly enhances the cell killing ability of Dox with respect to NCI/ADR‐RES cells in vitro. These findings suggest that such codelivery nanoplatforms provide a promising route for overcoming tumor MDR.
Optical and Electroluminescent Studies of White‐Light‐Emitting Copolymers Based on Poly(9,9‐dioctylfluorene) and Fluorenone Derivatives
Authors: Wang Hua , Yang Junli , Sun Jing , Xu Yang , Wu Yuling , Dong Qingcheng , Wong Wai‐Yeung , Hao Yuying , Zhang Xinwen , Li Hua 
Published: April 2014

A novel type of single white‐light‐emitting copolymers, PF‐DTFOx, derived from poly(9,9‐dioctylfluorene) (PF) in which 2,7‐di‐(2‐thienyl)‐9‐fluorenone (DTFO) is introduced as an orange‐emitting unit, is reported, and their application in white‐light polymer light‐emitting devices (PLEDs) is explored. Because of the very simple structure of DTFO, the synthetic routes to PF‐DTFOx are not complicated, and the raw materials are cheap; these are advantageous in reducing the fabrication cost of white‐light PLEDs. In the fluorescence spectra, PF‐DTFOx in solid powder shows dual peaks at around 460 and 560 nm. In white‐light PLEDs, the color of the white‐light emission is tunable; this can be achieved by changing the content of DTFO in PF‐DTFOx. The light‐emission color varies from blue‐white to pure white and orange‐white when the composition of DTFO increases. All the PLEDs based on PF‐DTFOx exhibit maximum luminance above 1800 cd m−2 and a color rendering index above 80.
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Honey bee colonies act as reservoirs for two Spiroplasma facultative symbionts and incur complex, multiyear infection dynamics
Authors: Schwarz Ryan S. , Teixeira Érica Weinstein , Tauber James P. , Birke Juliane M. , Martins Marta Fonseca , Fonseca Isabela , Evans Jay D. 
Published: April 2014

AbstractTwo species of Spiroplasma (Mollicutes) bacteria were isolated from and described as pathogens of the European honey bee, Apis mellifera, ~30 years ago but recent information on them is lacking despite global concern to understand bee population declines. Here we provide a comprehensive survey for the prevalence of these two Spiroplasma species in current populations of honey bees using improved molecular diagnostic techniques to assay multiyear colony samples from North America (U.S.A.) and South America (Brazil). Significant annual and seasonal fluctuations of Spiroplasma apis and Spiroplasma melliferum prevalence in colonies from the U.S.A. (n = 616) and Brazil (n = 139) occurred during surveys from 2011 through 2013. Overall, 33% of U.S.A. colonies and 54% of Brazil colonies were infected by Spiroplasma spp., where S. melliferum predominated over S. apis in both countries (25% vs. 14% and 44% vs. 38% frequency, respectively). Colonies were co‐infected by both species more frequently than expected in both countries and at a much higher rate in Brazil (52%) compared to the U.S.A. (16.5%). U.S.A. samples showed that both species were prevalent not only during spring, as expected from prior research, but also during other seasons. These findings demonstrate that the model of honey bee spiroplasmas as springtime‐restricted pathogens needs to be broadened and their role as occasional pathogens considered in current contexts.