bluuebunny/crossref_metadata_2025 huggingface dataset:
Two polydimethylsiloxane rod extraction methods for the sensitive determination of phenolic compounds in water samples
Authors: Valls‐Cantenys Carme , Iglesias Mònica , Salvadó Victòria
Published: October 2014

Simple, precise, and low‐cost methods for the simultaneous determination of phenolic endocrine disrupting compounds such as bisphenol A, trichlorophenol, pentachlorophenol, 4‐nonylphenol, and 4‐octylphenol in water samples were developed. The Direct, in situ derivatization methods are based on polydimethylsiloxane rod extraction followed by liquid desorption and chromatographic analysis by liquid chromatography and diode array detection. Several parameters affecting the extraction and desorption of the phenolic compounds and their acetylated derivates were studied, as well as the chromatographic and detection conditions. For the direct method, determination coefficients (r2) > 0.990 and LODs in the 0.6–2 μg/L range were obtained for all compounds except bisphenol A (9.5 μg/L). With the derivatization‐based method, based on in situ acetylation, lower limits of detection (0.3–0.9 μg/L) were obtained for all the compounds with r2 > 0.988 and RSDs in the 2–9% range. The developed methods were applied to the analysis of spiked water samples obtaining recoveries of between 60.2 and 131.7% for the direct method, and of between 76.6 and 108.2% for the derivatization‐based method. The results demonstrate the feasibility of using these two methods for determining bisphenol A, trichlorophenol, pentachlorophenol, 4‐nonylphenol, and 4‐octylphenol in water.
Simultaneous determination of seven phenolic acids in three Salvia species by capillary zone electrophoresis with β‐cyclodextrin as modifier
Authors: Cao Jiliang , Wei Jinchao , Tian Ke , Su Huanxing , Wan Jianbo , Li Peng
Published: October 2014

A capillary zone electrophoresis method was developed for the simultaneous determination of seven phenolic acids, including protocatechuic aldehyde (1), salvianolic acid C (2), rosmarinic acid (3), salvianolic acid A (4), danshensu (5), salvianolic acid B (6), and protocatechuic acid (7), in Danshen and related medicinal plants. A running buffer composed of 20 mM sodium tetraborate adjusted to pH 9.0, and containing 12 mM β‐cyclodextrin as modifier. Baseline separation was achieved within 17 min running at the voltage of 20 kV, temperature of 25°C and detection wavelength of 280 nm. The relative standard deviations of migration time ranged from 0.2 to 0.7% and the peak area ranged from 1.5 to 3.7% for the seven analytes, indicating the good repeatability of the proposed method. The method was extensively validated by evaluating the linearity (R2 ≥ 0.9992), limits of detection (0.14–0.36 μg/mL), limits of quantification (0.47–1.19 μg/mL), and recovery (96.0–102.6%). Under the optimum conditions, samples of Danshen and related medicinal plants were analyzed using the developed method with high separation efficiency.
The Calm before the Storm: Examining Emotion Regulation Consumption in the Face of an Impending Disaster
Authors: Kemp Elyria , Kennett‐Hensel Pamela A. , Williams Kim H.
Published: October 2014

In the midst of the physical damage and collective stress created by natural disasters, individuals come to terms with their utter lack of control. In the process, a myriad of emotions are experienced, with many of them being negative in nature. Research suggests that during moderately challenging situations individuals experiencing negative emotions may engage in coping attempts to improve their emotional state. Consumption has been one strategy used by individuals to mitigate negative emotions. This research extends previous research by exploring whether such emotion regulation processes occur in extreme conditions such as natural disasters. Specifically, it examines the emotions experienced by individuals, the antecedents of these emotions, as well as how individuals regulate their emotions through consumption. A conceptual model is proposed and tested in Study 1 and findings are once again corroborated in a follow‐up study. Implications for mitigating negative emotions and improving subjective well‐being during extreme crisis situations are discussed.
Effects of Construal Level on Omission Detection and Multiattribute Evaluation
Authors: Pfeiffer Bruce E. , Deval Hélène , Kardes Frank R. , Ewing Douglas R. , Han Xiaoqi , Cronley Maria L.
Published: October 2014

Research has demonstrated that consumers are commonly insensitive to missing information and that this insensitivity can lead them to form strong beliefs and evaluations on the basis of weak evidence. A growing body of research has shown that sensitivity to omissions can be heightened and that this increased sensitivity results in more appropriate evaluations. Expanding on this, the current research finds that the level of abstraction by which a situation is construed can influence the likelihood of omission detection and the resulting evaluative judgments. A series of studies reveal that people are more likely to spontaneously detect omissions in near vs. distant judgments, in concrete vs. abstract mindsets, and when they are inherently more likely to interpret actions in concrete vs. abstract terms. Further, although prior findings suggest that people may have differential sensitivity to primary and secondary missing features at different levels of construal, the current research finds no such difference. The results of this study indicate that people are more sensitive to all types of missing information when construal levels are low, and that this sensitivity leads to more moderate and appropriate judgments.
Who is the “Self” that Buys?: An Exploratory Examination of Imaginative Consumption and Explanation of Opinion Leadership
Authors: Cowan Kirsten L. , Dai Bo
Published: October 2014

The present research, first, combines literatures on self‐theory, imaginative consumption, and opinion leadership. Second, the research, using self‐theory, explores individual difference variables predictive of imaginative consumption in two studies using different populations. The results reveal fashion product involvement, self‐esteem, fashion knowledge, idea shopping motivation, and probability of a mispurchase influence the degree to which an individual imaginatively consumes fashion products. Third, the research makes a contribution by explaining from where opinion leaders derive their abilities—imaginative consumption. In contributing to scholarly work, the research explains the role of imagination and opinion leadership in both theories of self‐verification and self‐enhancement. Managerial implications include identifying potential opportunities for marketing communications and retail management. The findings are promising and encourage further exploration of the phenomenon of imaginative consumption.
Eclipsing: When Celebrities Overshadow the Brand
Authors: Ilicic Jasmina , Webster Cynthia M.
Published: October 2014

This paper applies Gestalt psychology and associative network theory to examine the effect of eclipsing in celebrity endorsement on consumer attitude towards the endorsed brand. Eclipsing occurs when the celebrity overshadows the endorsed brand by dominating in an advertisement and diminishing the associative link between the celebrity and endorsed brand. Three studies take into account match‐up, celebrity attachment, brand familiarity, and the moderating role of eclipsing, through manipulating two levels of eclipsing in advertising: (1) high eclipsing, when the celebrity is the focus, and (2) low eclipsing, when both the celebrity and brand are emphasized. Consumers who have a weak attachment to the celebrity endorser report a more positive brand attitude when they see the celebrity and endorsed brand both emphasized in an advertisement (low eclipsing) than when the celebrity overshadows and dominates the brand (high eclipsing), irrespective of whether consumers perceive the celebrity and brand to match or mismatch. For consumers with strong celebrity attachment, high eclipsing enhances brand attitude, regardless of whether they perceive the celebrity and brand to either match or mismatch. The findings of these studies have significant implications for advertisers and brand managers in the execution of their advertisements featuring endorsements.
The Design of Dextran‐Based Hypoxia‐Inducible Hydrogels via In Situ Oxygen‐Consuming Reaction
Authors: Park Kyung Min , Blatchley Michael R. , Gerecht Sharon
Published: October 2014

Hypoxia plays a critical role in the development and wound healing process, as well as a number of pathological conditions. Here, dextran‐based hypoxia‐inducible (Dex‐HI) hydrogels formed with in situ oxygen consumption via a laccase−medicated reaction are reported. Oxygen levels and gradients were accurately predicted by mathematical simulation. It is demonstrated that Dex‐HI hydrogels provide prolonged hypoxic conditions up to 12 h. The Dex‐HI hydrogel offers an innovative approach to delineate not only the mechanism by which hypoxia regulates cellular responses, but may facilitate the discovery of new pathways involved in the generation of hypoxic and oxygen gradient environments.

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Core‐and‐Surface‐Functionalized Polyphenylene Dendrimers for Solution‐Processed, Pure‐Blue Light‐Emitting Diodes Through Surface‐to‐Core Energy Transfer
Authors: Zhang Guang , Baumgarten Martin , Auer Manuel , Trattnig Roman , List‐Kratochvil Emil J. W. , Müllen Klaus
Published: October 2014

Several pyrene‐based polyphenylene dendrimers (PYPPDs) with different peripheral chromophores (PCs) are synthesized and characterized. Deep blue emissions solely from the core are observed for all of them in photoluminescence spectra due to good steric shielding of the core and highly efficient surface‐to‐core Förster resonant energy transfers (FRETs). Device performances are found in good correlation with the energy gaps between the work function of the electrodes and the frontier molecular orbital (FMO) levels of the PCs. Pure blue emission, luminance as high as 3700 cd m−2 with Commission Internationale de l'Éclairage 1931 (CIExy) = (0.16, 0.21), and a peak current efficiency of 0.52 cd A−1 at CIExy = (0.17, 0.20) are achieved. These dendrimers are among the best dendritic systems so far for fluorescent blue light‐emitting materials.

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Quantification of multiple compounds containing heterogeneous elements in the mixture by one‐dimensional nuclear magnetic resonance spectroscopy of different nuclei using a single universal concentration reference
Authors: Xu Li , Shi Xiaohuo , Hu Kaifeng
Published: October 2014

One‐dimensional (1D) quantitative NMR (qNMR) is a useful tool for concentration determination due to its experimental simplicity and the direct proportionality of the integrated signal area to the number of nuclei spin. For complex mixtures, however, signal overlapping often in one‐dimensional quantitative 1H NMR (1D 1H qNMR) spectrum limits the accurate quantification of individual compound. Here, we introduced employing joint 1D qNMR methods of different nuclei, such as 1H and 31P (or/and 19F), to quantify multiple compounds in a complex mixture using a single universal concentration reference. When the concentration ratio of several compounds containing different elements in a complex mixture is of interest, the result calculated from measured intensities from 1D qNMR of different nuclei is independent of the gravimetric error from the reference. In this case, the common reference also serves as a ‘quantitative bridge’ among these 1D qNMR of different nuclei. Quantitative analysis of choline, phosphocholine, and glycerophosphocholine mixture is given as an example using trimethylphosphine oxide ((CH3)3P(O)) as concentration reference. Compounds containing multiple elements, such as tetramethylammonium hexafluorophosphate (N+(CH3)4PF6−), are proposed as the common concentration reference for 1H, 13C, 15N, 31P, and 19F qNMR for the quantitative analysis of complex mixture containing these different elements. We anticipate that the proposed joint 1D qNMR approach using a universal concentration reference will be a valuable alternative for simultaneous quantification of multiple compounds in a complex mixture due to its accuracy and single and simple sample preparation. Copyright © 2014 John Wiley & Sons, Ltd.
Polymer‐stabilized blue phases: promising mesophases for a new generation of liquid crystal displays
Authors: Nordendorf G. , Hoischen A. , Schmidtke J. , Wilkes D. , Kitzerow H.‐S.
Published: October 2014

Blue phases—special chiral liquid crystalline mesophases—are promising candidates for electro‐optic devices with improved performance and simplified fabrication. A necessary precondition for possible applications is a significantly enhanced temperature range of their existence, which can be achieved by a cross‐linked polymer network formed byin situpolymerization. Unlike many other mesophases, blue phases are optically isotropic if no voltage is applied. Regarding the transmission of a blue phase cell placed between crossed polarizers, the optical isotropy enables—at least in principle—a perfect dark state, independent of the viewing angle, without the necessity of any alignment layer. The application of an in‐plane electric field induces a strong birefringence (Kerr effect). The effective Kerr constants are much larger than those of isotropic liquids, and the switching times between the dark and the induced bright state are in the submillisecond range. Some basic properties of blue phases, state‐of‐the‐art performance, and remaining challenges of the development of polymer‐stabilized blue phases are reviewed in this article. Copyright © 2014 John Wiley & Sons, Ltd.
Fetal lung growth represented by longitudinal changes in MRI‐derived fetal lung volume parameters predicts survival in isolated left‐sided congenital diaphragmatic hernia
Authors: Coleman Alan , Phithakwatchara Nisarat , Shaaban Aimen , Keswani Sundeep , Kline‐Fath Beth , Kingma Paul , Haberman Beth , Lim Foong‐Yen
Published: October 2014

Objective

The aim of this study was to evaluate fetal lung growth rate for isolated left‐sided congenital diaphragmatic hernia (CDH) using serial magnetic resonance imaging (MRI)‐based volumetric measures.

Methods

Early and late gestational (22–30 and >30 weeks' gestation) lung volumetry was obtained by fetal MRI in 47 cases of isolated left‐sided CDH. At both of these time points, lung volume indices, including total lung volume (TLV), observed to expected TLV (o/e TLV), and percentage of predicted lung volume (PPLV) as well as their change rates (Δ) and relative Δ during gestation were calculated and analyzed in regard to their capacity to predict neonatal survival.

Results

TLV, o/e TLV, and PPLV had various changes during gestation. Late TLV, early and late o/e TLV, and late PPLV were predictive of neonatal survival. Non‐survivors had lower ΔTLV and more negative relative ΔPPLV than survivors (1.18 vs 1.85 mL/week, P = 0.004 and −4.15%/week vs −1.95%/week, P = 0.002, respectively).

Conclusions

The severity of pulmonary hypoplasia is dynamic and can worsen in the third trimester. MRI lung volumetry repeated in late gestation can provide additional information on individual lung growth that may facilitate prenatal counseling and focus perinatal management. © 2014 John Wiley & Sons, Ltd.
1‐Phenyl‐1,2,4,6‐cycloheptatetraene: the missing intermediate of the diphenylcarbene to fluorene rearrangement
Authors: Costa Paolo , Sander Wolfram
Published: October 2014

The photochemistry of diphenylcarbene 5, matrix‐isolated in argon at 3–5 K was investigated by UV–Vis, IR, and EPR spectroscopy. Although carbene 5 proved to be stable toward broadband UV irradiation, it slowly rearranges to 1‐phenyl‐1,2,4,6‐cycloheptatetraene 8 during irradiation with the intense light of a 445‐nm diode laser. Other intermediates were not observed. Allene 8 is the key intermediate that was missing in the proposed mechanism of the rearrangement of 5 to fluorene 7. Copyright © 2014 John Wiley & Sons, Ltd.
A First Rock Glacier Inventory for the Bolivian Andes
Authors: Rangecroft Sally , Harrison Stephan , Anderson Karen , Magrath John , Castel Ana Paola , Pacheco Paula
Published: October 2014

Rock glaciers in the arid Bolivian Andes are potentially important water sources, but little is known about their spatial distribution and characteristics. We provide the first rock glacier inventory for the region (15–22°S), based on mapping using remote sensing data in Google Earth, supported by field validation. Of the 94 rock glaciers identified, 57 per cent were classified as active (containing ice) and the remaining as relict (not containing ice). The majority (87%) have a southerly aspect (SE, S and SW), and the rock glacier length and area averages were 500 m and 0.12 km2, respectively. We approximate the lower limit of permafrost to be at 4700 m in the Bolivian Andes, with the mean minimum altitude of rock glacier fronts estimated to be 4980 m for active rock glaciers, and about 100 m lower for relict rock glaciers. The inventory provides an important first step towards assessing the spatial distribution of regional permafrost as well as information to allow permafrost‐based water resources in the Bolivian Andes to be understood against a backdrop of severe glacier recession. Copyright © 2014 John Wiley & Sons, Ltd.
Use of a structural alphabet to find compatible folds for amino acid sequences
Authors: Mahajan Swapnil , de Brevern Alexandre G. , Sanejouand Yves‐Henri , Srinivasan Narayanaswamy , Offmann Bernard
Published: October 2014

The structural annotation of proteins with no detectable homologs of known 3D structure identified using sequence‐search methods is a major challenge today. We propose an original method that computes the conditional probabilities for the amino‐acid sequence of a protein to fit to known protein 3D structures using a structural alphabet, known as “Protein Blocks” (PBs). PBs constitute a library of 16 local structural prototypes that approximate every part of protein backbone structures. It is used to encode 3D protein structures into 1D PB sequences and to capture sequence to structure relationships. Our method relies on amino acid occurrence matrices, one for each PB, to score global and local threading of query amino acid sequences to protein folds encoded into PB sequences. It does not use any information from residue contacts or sequence‐search methods or explicit incorporation of hydrophobic effect. The performance of the method was assessed with independent test datasets derived from SCOP 1.75A. With a Z‐score cutoff that achieved 95% specificity (i.e., less than 5% false positives), global and local threading showed sensitivity of 64.1% and 34.2%, respectively. We further tested its performance on 57 difficult CASP10 targets that had no known homologs in PDB: 38 compatible templates were identified by our approach and 66% of these hits yielded correctly predicted structures. This method scales‐up well and offers promising perspectives for structural annotations at genomic level. It has been implemented in the form of a web‐server that is freely available at http://www.bo‐protscience.fr/forsa.
The solution structure of the forkhead box‐ODNA binding domain of Brugia malayiDAF‐16a
Authors: Casper Sarah K. , Schoeller Scott J. , Zgoba Danielle M. , Phillips Andrew J. , Morien Thomas J. , Chaffee Gary R. , Sackett Peter C. , Peterson Francis C. , Crossgrove Kirsten , Veldkamp Christopher T.
Published: October 2014

Brugia malayi is a parasitic nematode that causes lymphatic filariasis in humans. Here the solution structure of the forkhead DNA binding domain of Brugia malayi DAF‐16a, a putative ortholog of Caenorhabditis elegans DAF‐16, is reported. It is believed to be the first structure of a forkhead or winged helix domain from an invertebrate. C. elegans DAF‐16 is involved in the insulin/IGF‐I signaling pathway and helps control metabolism, longevity, and development. Conservation of sequence and structure with human FOXO proteins suggests that B. malayi DAF‐16a is a member of the FOXO family of forkhead proteins. Proteins 2014; 82:3490–3496. © 2014 Wiley Periodicals, Inc.
Compatibility of reduced‐risk insecticides with the non‐target predatory mite Iphiseius degenerans (Acari: Phytoseiidae)
Authors: Döker İsmail , Pappas Maria L , Samaras Konstantinos , Triantafyllou Anneta , Kazak Cengiz , Broufas George D
Published: October 2014

BACKGROUND

Iphiseius degenerans (Berlese) (Acari: Phytoseiidae) is a common predatory mite in citrus orchards in some areas of the Mediterranean basin and an important biological control agent of the thrips Frankliniella occidentalis (Pergande) in Integrated Pest Management (IPM) programmes in greenhouse crops. In this study, we evaluated the effects of the ‘reduced‐risk’ insecticides acetamiprid, chlorantraniliprole, flubendiamide, metaflumizone, methoxyfenozide, spinetoram and thiamethoxam on I. degenerans, as a means of testing their compatibility in IPM programmes.

RESULTS

Although all pesticides decreased immature survival, high mortality was only recorded for young larvae when exposed to acetamiprid, while metaflumizone, thiamethoxam and spinetoram resulted in intermediate lethal effects. The estimated LC50 values of acetamiprid, spinetoram and thiamethoxam for I. degenerans females were 0.52, 0.84 and 0.16‐fold lower than the respective maximum recommended doses of the pesticides for field application. Although all pesticides tested significantly decreased fecundity, highest rates corresponded to the three pesticides already mentioned.

CONCLUSION

Chlorantraniliprole, flubendiamide and methoxyfenozide may preliminarily be included in IPM programmes, whereas the effects of acetamiprid, metaflumizone, spinetoram and thiamethoxam on I. degenerans should be clarified in further field toxicological tests. This information could be useful for rationally planning and implementing pest management on a sustainable basis. © 2014 Society of Chemical Industry
Resistance to lambda‐cyhalothrin in Spanish field populations of Ceratitis capitata and metabolic resistance mediated by P450 in a resistant strain
Authors: Arouri Rabeh , Le Goff Gaelle , Hemden Hiethem , Navarro‐Llopis Vicente , M'saad Mariem , Castañera Pedro , Feyereisen René , Hernández‐Crespo Pedro , Ortego Félix
Published: October 2014

BACKGROUND

The withdrawal of malathion in the European Union in 2009 resulted in a large increase in lambda‐cyhalothrin applications for the control of the Mediterranean fruit fly, Ceratitis capitata, in Spanish citrus crops.

RESULTS

Spanish field populations of C. capitata have developed resistance to lambda‐cyhalothrin (6–14‐fold), achieving LC50 values (129–287 ppm) higher than the recommended concentration for field treatments (125 ppm). These results contrast with the high susceptibility to lambda‐cyhalothrin found in three Tunisian field populations. We have studied the mechanism of resistance in the laboratory‐selected resistant strain W‐1Kλ (205‐fold resistance). Bioassays with synergists showed that resistance was almost completely suppressed by the P450 inhibitor PBO. The study of the expression of 53 P450 genes belonging to the CYP4, CYP6, CYP9 and CYP12 families in C. capitata revealed that CYP6A51 was overexpressed (13–18‐fold) in the resistant strain. The W‐1Kλ strain also showed high levels of cross‐resistance to etofenprox (240‐fold) and deltamethrin (150‐fold).

CONCLUSION

Field‐evolved resistance to lambda‐cyhalothrin has been found in C. capitata. Metabolic resistance mediated by P450 appears to be the main resistance mechanism in the resistant strain W‐1Kλ. The levels of cross‐resistance found may compromise the effectiveness of other pyrethroids for the control of this species. © 2014 Society of Chemical Industry
Infrared defect dynamics: He irradiation induced complexes in high‐quality silicon crystal
Authors: Inoue Naohisa , Goto Yasunori , Sugiyama Takahide , Watanabe Kaori , Seki Hirofumi , Kawamura Yuichi
Published: October 2014

The behavior of radiation‐induced complexes in MCZ silicon crystal after He irradiation was studied by highly sensitive and accurate infrared absorption spectroscopy. Samples from the same crystal that was used in the electron irradiation were employed. Many absorption lines with peak absorbance as small as 10−6 were successfully detected. Most of them were the same as those that had been observed in the electron irradiated samples and reported in the previous papers. Not only C‐rich type complexes such as CiOi and ICiOi, but also C‐lean type complexes such as I2O2i and IO3i were observed, in contrast to the electron case where only C‐rich type had been observed in the same crystal. Peak absorbances for the He case are about half of those in the electron case. The He dose was 5 × 1013 cm−2, 1/200 of the electron dose of 1016 cm−2. Thus, the complex production rate per particle in the He case was about 100 times as large as that for electrons. The production range in the He case was restricted to within 20 microns from the surface. This range amounted to about 1/100 of that observed in the electron case where complexes had been formed uniformly throughout the 2 mm thick sample. Also, therefore, the complex concentration in the layer was about 100 times higher than that in the electron case. The annealing behavior of complexes was essentially the same as that in the electron case with minor differences.
A note regarding meta‐analysis of sequential trials with stopping for efficacy
Authors: Senn Stephen
Published: October 2014

It is shown that fixed‐effect meta‐analyses of naïve treatment estimates from sequentially run trials with the possibility of stopping for efficacy based on a single interim look are unbiassed (or at the very least consistent, depending on the point of view) provided that the trials are weighted by information provided. A simple proof of this is given. An argument is given suggesting that this also applies in the case of multiple looks. The implications for this are discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Effect of Ginger (Zingiber officinale) on Heavy Menstrual Bleeding: A Placebo‐Controlled, Randomized Clinical Trial
Authors: Kashefi Farzaneh , Khajehei Marjan , Alavinia Mohammad , Golmakani Ebrahim , Asili Javad
Published: October 2014

Objective: A wide range of herbal plants have been reported to treat various gynecological problems of women. This study was set out to investigate the effect of ginger (Zingiber officinale) on heavy menstrual bleeding (HMB) in high school girls. Methods: Ninety‐two young women who experienced HMB and met the inclusion criteria were recruited in this study. Participants were evaluated for six consecutive menstrual cycles. During 3 assessment cycles, their HMB was confirmed by Pictorial Blood Assessment Chart. They were then randomly allocated to two study groups to receive either ginger or placebo capsules. The participants filled in the same chart during three intervention cycles. Results: The level of menstrual blood loss dramatically declined during the three intervention cycles in ginger‐receiving group. The decrease of blood loss in ginger‐receiving group was significantly more remarkable than that of participants receiving placebo (p < 0.001). Minimum number of participants reported adverse effects. Conclusion: HMB is highly prevalent among young women. Considering the significance of appropriate and timely treatment and also the importance of prevention of unwanted consequences, ginger may be considered as an effective therapeutic option for HMB. Copyright © 2014 John Wiley & Sons, Ltd.
Reactivity dynamics of a confined molecule in presence of an external magnetic field
Authors: Khatua Munmun , Sarkar Utpal , Chattaraj Pratim Kumar
Published: October 2014

Reactivity dynamics and stability of a confined hydrogen molecule in presence of an external magnetic field has been studied using quantum fluid density functional theory. Dynamic profiles of various reactivity parameters such as hardness, electrophilicity, magnetizability, phase volume, entropy, etc. have been studied within a confined environment. Responses in the reactivity parameters as well as the associated electronic structure principles validate the stability of the confined H2 molecule in ground and excited states in presence of an external magnetic field. Confinement to the system has been imposed by the Dirichlet type boundary condition. Confinement and excitation act in opposite directions. Ground state type dynamics is obtained on simultaneous electronic excitation and confinement. © 2014 Wiley Periodicals, Inc.
A constrained extremum‐seeking control approach
Authors: Guay Martin , Moshksar Ehsan , Dochain Denis
Published: October 2014

This paper proposes an extremum‐seeking control approach for a class of uncertain nonlinear dynamical systems subject to constraints. It is assumed that the objective function along with the constraints are available for measurement. The contribution of the paper is to formulate the extremum‐seeking problem as a time‐varying estimation problem. The constraints are enforced by using an interior point strategy that preserves feasibility of the systems' trajectories. Simulation examples are used to illustrate the effectiveness of the proposed technique. Copyright © 2014 John Wiley & Sons, Ltd.
Generalized estimating equations for genome‐wide association studies using longitudinal phenotype data
Authors: Sitlani Colleen M. , Rice Kenneth M. , Lumley Thomas , McKnight Barbara , Cupples L. Adrienne , Avery Christy L. , Noordam Raymond , Stricker Bruno H. C. , Whitsel Eric A. , Psaty Bruce M.
Published: October 2014

Many longitudinal cohort studies have both genome‐wide measures of genetic variation and repeated measures of phenotypes and environmental exposures. Genome‐wide association study analyses have typically used only cross‐sectional data to evaluate quantitative phenotypes and binary traits. Incorporation of repeated measures may increase power to detect associations, but also requires specialized analysis methods. Here, we discuss one such method—generalized estimating equations (GEE)—in the contexts of analysis of main effects of rare genetic variants and analysis of gene‐environment interactions. We illustrate the potential for increased power using GEE analyses instead of cross‐sectional analyses. We also address challenges that arise, such as the need for small‐sample corrections when the minor allele frequency of a genetic variant and/or the prevalence of an environmental exposure is low. To illustrate methods for detection of gene‐drug interactions on a genome‐wide scale, using repeated measures data, we conduct single‐study analyses and meta‐analyses across studies in three large cohort studies participating in the Cohorts for Heart and Aging Research in Genomic Epidemiology consortium—the Atherosclerosis Risk in Communities study, the Cardiovascular Health Study, and the Rotterdam Study. Copyright © 2014 John Wiley & Sons, Ltd.
Nanoscopy for nanoscience: how super‐resolution microscopy extends imaging for nanotechnology
Authors: Johnson Sam A.
Published: October 2014

Imaging methods have presented scientists with powerful means of investigation for centuries. The ability to resolve structures using light microscopes is though limited to around 200 nm. Fluorescence‐based super‐resolution light microscopy techniques of several principles and methods have emerged in recent years and offer great potential to extend the capabilities of microscopy. This resolution improvement is especially promising for nanoscience where the imaging of nanoscale structures is inherently restricted by the resolution limit of standard forms of light microscopy. Resolution can be improved by several distinct approaches including structured illumination microscopy, stimulated emission depletion, and single‐molecule positioning methods such as photoactivated localization microscopy and stochastic optical reconstruction microscopy and several derivative variations of each of these. These methods involve substantial differences in the resolutions achievable in the different axes, speed of acquisition, compatibility with different labels, ease of use, hardware complexity, and compatibility with live biological samples. The field of super‐resolution imaging and its application to nanotechnology is relatively new and still rapidly developing. An overview of how these methods may be used with nanomaterials is presented with some examples of pioneering uses of these approaches. WIREs Nanomed Nanobiotechnol 2015, 7:266–281. doi: 10.1002/wnan.1300

This article is categorized under:

Nanotechnology Approaches to Biology > Cells at the Nanoscale
First Polymeric Polyphosphide via Solution Chemistry – Synthesis and Crystal Structure of CsP7
Authors: Meier Martin , Faupel Victoria , Korber Nikolaus
Published: October 2014

For the first time, CsP7 was synthesized via a solution reaction in liquid ammonia at low temperatures. The blood‐red compound is air and moisture sensitive. The crystal structure of CsP7 was determined by single‐crystal X‐ray diffraction at 123 K. CsP7 crystallizes in the orthorhombic space group Pbcm (No. 57) with a = 9.0820(2) Å, b = 9.4193(2) Å, c = 9.65483(19) Å, Z = 4 and V = 825.93(3) Å3. CsP7 is isotypic with RbP7. The crystal structure is comprised of Cs+ cations as well as one‐dimensionally extended P7– chains proceeding along the c axis. The chains consist of nortricyclane‐like P7 cages linked in a linear fashion. Thus, for the very first time, a binary compound containing a polymeric Zintl anion was synthesized by a solution reaction in liquid ammonia.
Synthesis of Titanium Fluorophosphates and Fluorosulfates from Hexafluorotitanic Acid
Authors: Marshall Kayleigh L. , Weller Mark T.
Published: October 2014

Three new titanium‐based network structures and an organic tetraazapentacenium [TiF6]2– salt were synthesized under high fluoride‐concentration, hydrothermal conditions utilizing hexafluorotitanic acid as a starting material. The compositions of the new connected‐structure phases obtained are CsTi2F2(PO4)(PO3F)2, [Imidazole‐H][Ti3F2(PO3F)(PO4)3]·0.5H2O, and [DABCO‐H][Ti(SO4)2(SO3(OH,F))]. CsTi2F2(PO4)(PO3F)2 has a sheet‐like structure with interlayer Cs+ ions coordinated solely by fluoride ions, whereas [Imidazole‐H] [Ti3F2(PO3F)(PO4)3]·0.5H2O has a three‐dimensional framework structure with elliptical channels containing pairs of organic template molecules. The DABCO templated phase is isostructural with ferrinatrite with chains formed from titanium coordinated by six sulfate groups. Reactions using 1,2‐phenylenediamine under these conditions surprisingly generates 5,12‐dihydro‐5,7,12,14‐tetraazapentacenium cations, which crystallize as a salt with [TiF6]2–.
Synthesis and Characterization of the Cerium(III) UV‐Emitting 2D‐Coordination Polymer 2∞[Ce2Cl6(4, 4′‐bipyridine)4]·py
Authors: Matthes Philipp R. , Müller‐Buschbaum Klaus
Published: October 2014

The 2D‐coordination polymer 2∞[Ce2Cl6(bipy)4]·py (bipy = 4, 4′‐bipyridine) shows a 5d‐4f centered emission in the soft UV‐B region. It was synthesized via the reaction of anhydrous CeCl3 and 4, 4′‐bipyridine in pyridine under solvothermal conditions. The two‐dimensional sheet structure consisting of 4, 4′‐bipyridine coordinated Ce2Cl6 dimers closes the gap between the known lanthanum 3∞[La2Cl6(bipy)5]·4bipy framework and the 2D networks of the formula 2∞[Ln2Cl6(bipy)3]·2bipy from praseodymium on. They differ in the number of coordinating bipy linkers, which decreases along La > Ce > Pr, with the remarkable observation that lanthanum, cerium, and praseodymium exhibit different network constitutions. The structure of 2∞[Ce2Cl6(bipy)4]·py exhibits a cem topology constituted of double strands, which are diagonally linked by 4, 4′‐bipyridine forming trapezoid cavities in‐between the strands. The cavities contain intercalated pyridine molecules.
Metal‐Centered Zintl Ions Isolated by Direct Extraction from Endohedral Intermetallic Precursor: [Co1–x@Sn9]4– (x ≈ 0.32) and [Co2@Sn17]5–
Authors: He Haiyan , Klein Wilhelm , Jantke Laura‐Alice , Fässler Thomas F.
Published: October 2014

Two new compounds with Co‐centered Sn9 clusters were obtained by the extraction directly from the intermetallic precursor K4.79Co0.79Sn9 in ethylenediamine with addition of cryptand [2.2.2]. The anions [Co0.68@Sn9]4– in K[K([2.2.2]crypt)]3[Co0.68@Sn9] (1) consisting of overlaying [Co@Sn9]4– and [Sn9]4– cluster anions are connected by K atoms to form infinite $\rm^{1}_{\infty}$K[Co0.68@Sn9] chains. The anions [Co2@Sn17]5– in [K([2.2.2]crypt)]5[Co2@Sn17]·en·tol (2) are built from two [Co@Sn9] sharing one common Sn atom, with the same composition but a different conformation as in the previously reported [K([2.2.2]crypt)]5[Co2@Sn17]. Quantum chemical calculations for the different conformers of [Co2@Sn17]5– reveal that both conformers are rather close in energy and that the short intercluster Sn–Sn distance in 2 does not originate from attractive interactions.
Reproductive interference in laboratory experiments of interspecific competition
Authors: Kishi Shigeki
Published: October 2014

Many studies that have researched interspecific competition inCallosobruchus(bean beetles),Drosophila(fruit flies), andTribolium(flour beetles) have considered the major drivers of interspecific competition to be interspecific resource competition and intraguild cannibalism. These competition drivers have a density‐dependent effect on the population dynamics. However, some studies have also detected a relative‐frequency‐dependent effect in the observed population dynamics. The most likely causal mechanism of this relative frequency dependence is reproductive interference, defined as any interspecific sexual interaction that damages female reproductive success. Reproductive interference has been overlooked by most laboratory studies in spite of the critical effect on the competition outcome. In this paper, I review laboratory studies of these insect genera from the perspective of reproductive interference and show that the reported results can be more reasonably interpreted by the joint action of reproductive interference and resource competition, including intraguild cannibalism. In addition, on the basis of results reported by a small number of related studies, I discuss the behavioral and evolutionary changes induced in those genera by reproductive interference.
Interfacial and Solution Behavior of Amphiphilic Drug and Counterion‐Coupled Gemini (COCOGEM) Surfactants
Authors: Noori Sahar , Naqvi Andleeb Z. , Ansari Wajid H. , Kabir‐ud‐Din
Published: October 2014

The critical micelle concentrations (cmc) of mixed systems comprising an amphiphilic drug amitriptyline hydrochloride and counterion‐coupled gemini surfactants 12‐6‐12, 14‐6‐14, or 16‐6‐16 [1,6‐bis(N,N‐alkyldimethylammonium) adipate] were determined using tensiometry. The results were analyzed in the light of different theoretical models from Rosen, Clint, Rubingh, and Motomura. The cmc values decrease with increasing mole fraction of surfactant (α1). The cmcid values (cmc value at ideal mixing conditions) also decrease with α1 but remain above the experimental cmc values. This means that the mixed micelles form as a result of attractive interactions. These interactions are also seen in surface excess concentration (Γmax) and minimum area per molecule (Amin) data: Γmax increases and Amin decreases. Both Rosen's and Rubingh's models indicate synergistic interactions (interaction parameter, βm and βσ, values are negative). The βm values are larger in magnitude than βσ for 14‐6‐14 and 16‐6‐16 systems, whereas the reverse is the case with 12‐6‐12 because the surfactant's short chain makes adjustment in the core difficult for both components.
Effect of Compounds Affecting ABCA1 Expression and CETP Activity on the HDL Pathway Involved in Intestinal Absorption of Lutein and Zeaxanthin
Authors: Niesor Eric J. , Chaput Evelyne , Mary Jean‐Luc , Staempfli Andreas , Topp Andreas , Stauffer Andrea , Wang Haiyan , Durrwell Alexandre
Published: October 2014

The antioxidant xanthophylls lutein and zeaxanthin are absorbed from the diet in a process involving lipoprotein formation. Selective mechanisms exist for their intestinal uptake and tissue‐selective distribution, but these are poorly understood. We investigated the role of high‐density lipoprotein (HDL), apolipoprotein (apo) A1 and ATP‐binding cassette transporter (ABC) A1 in intestinal uptake of lutein in a human polarized intestinal cell culture and a hamster model. Animals received dietary lutein and zeaxanthin and either a liver X receptor (LXR) agonist or statin, which up‐ or down‐regulate intestinal ABCA1 expression, respectively. The role of HDL was studied following treatment with the cholesteryl ester transfer protein (CETP) modulator dalcetrapib or the CETP inhibitor anacetrapib. In vitro, intestinal ABCA1 at the basolateral surface of enterocytes transferred lutein and zeaxanthin to apoA1, not to mature HDL. In hamsters, plasma lutein and zeaxanthin levels were markedly increased with the LXR agonist and decreased with simvastatin. Dalcetrapib, but not anacetrapib, increased plasma and liver lutein and zeaxanthin levels. ABCA1 expression and apoA1 acceptor activity are important initial steps in intestinal uptake and maintenance of lutein and zeaxanthin levels by an HDL‐dependent pathway. Their absorption may be improved by physiological and pharmacological interventions affecting HDL metabolism.
Managing the load on a reader’s mind
Authors: Leppink Jimmie
Published: October 2014

None
tRNA modifications regulate translation during cellular stress
Authors: Gu Chen , Begley Thomas J. , Dedon Peter C.
Published: October 2014

The regulation of gene expression in response to stress is an essential cellular protection mechanism. Recent advances in tRNA modification analysis and genome‐based codon bias analytics have facilitated studies that lead to a novel model for translational control, with translation elongation dynamically regulated during stress responses. Stress‐induced increases in specific anticodon wobble bases are required for the optimal translation of stress response transcripts that are significantly biased in the use of degenerate codons keyed to these modified tRNA bases. These findings led us to introduce the notion of tRNA modification tunable transcripts (MoTTs – transcripts whose translation is regulated by tRNA modifications), which are identifiable using genome‐wide codon counting algorithms. In support of this general model of translational control of stress response, studies making use of detailed measures of translation, tRNA methyltransferase mutants, and computational and mass spectrometry approaches reveal that stress reprograms tRNA modifications to translationally regulate MoTTs linked to arginine and leucine codons, which helps cells survive insults by damaging agents. These studies highlight how tRNA methyltransferase activities and MoTTs are key components of the cellular stress response.
Lumican: A new inhibitor of matrix metalloproteinase‐14 activity
Authors: Pietraszek Katarzyna , Chatron-Colliet Aurore , Brézillon Stéphane , Perreau Corinne , Jakubiak-Augustyn Anna , Krotkiewski Hubert , Maquart François-Xavier , Wegrowski Yanusz
Published: October 2014

We previously showed that lumican regulates MMP‐14 expression. The aim of this study was to compare the effect of lumican and decorin on MMP‐14 activity. In contrast to decorin, the glycosylated form of lumican was able to significantly decrease MMP‐14 activity in B16F1 melanoma cells. Our results suggest that a direct interaction occurs between lumican and MMP‐14. Lumican behaves as a competitive inhibitor which leads to a complete blocking of the activity of MMP‐14. It binds to the catalytic domain of MMP‐14 with moderate affinity (K
D
∼ 275 nM). Lumican may protect collagen against MMP‐14 proteolysis, thus influencing cell–matrix interaction in tumor progression.
Structural and functional characterization of salmon STAT1, STAT2 and IRF9 homologs sheds light on interferon signaling in teleosts
Authors: Sobhkhez Mehrdad , Skjesol Astrid , Thomassen Ernst , Tollersrud Linn Greiner , Iliev Dimitar B. , Sun Baojian , Robertsen Børre , Jørgensen Jorunn B.
Published: October 2014

Mammalian IRF9 and STAT2, together with STAT1, form the ISGF3 transcription factor complex, which is critical for type I interferon (IFN)‐induced signaling, while IFNγ stimulation is mediated by homodimeric STAT1 protein. Teleost fish are known to possess most JAK and STAT family members, however, description of their functional activity in lower vertebrates is still scarce. In the present study we have identified two different STAT2 homologs and one IRF9 homolog from Atlantic salmon (Salmo salar). Both proteins have domain‐like structures with functional motifs that are similar to higher vertebrates, suggesting that they are orthologs to mammalian STAT2 and IRF9. The two identified salmon STAT2s, named STAT2a and STAT2b, showed high sequence identity but were divergent in their transactivation domain (TAD). Like STAT1, ectopically expressed STAT2a and b were shown to be tyrosine phosphorylated by type I IFNs and, interestingly, also by IFNγ. Microscopy analyses demonstrated that STAT2 co‐localized with STAT1a in the cytoplasm of unstimulated cells, while IFNa1 and IFNγ stimulation seemed to favor their nuclear localization. Overexpression of STAT2a or STAT2b together with STAT1a activated a GAS‐containing reporter gene construct in IFNγ‐stimulated cells. The highest induction of GAS promoter activation was found in IFNγ‐stimulated cells transfected with IRF9 alone. Taken together, these data suggest that salmon STAT2 and IRF9 may have a role in IFNγ‐induced signaling and promote the expression of GAS‐driven genes in bony fish. Since mammalian STAT2 is primarily an ISGF3 component and not involved in IFNγ signaling, our finding features a novel role for STAT2 in fish.
Neonatal seizures and epilepsies
Authors: Vinayan Kollencheri , Moshé Solomon
Published: October 2014

Neonatal seizure is the most frequent clinical manifestation of central nervous system dysfunction in the newborn. It is defined as a paroxysmal alteration in neurologic function that include motor, behavior and/or autonomic functions occurring in the first 28 days after birth of a term neonate or before 44 weeks of gestational age in a preterm infant. Seizures in the presence of encephalopathy are the most important clinical pattern of an acute cerebral insult in the immature brain. Chronic epileptic disorders very rarely may have their onset in the neonatal period and may persist well into infancy and later childhood. Structural brain defects and metabolic disorders constitute a substantial proportion of this group. Ictal EEG recordings remain the gold standard for the accurate identification of neonatal seizures of cortical origin and for the distinction from non-epileptic paroxysmal events. This review focuses on the electroclinical patterns of neonatal seizures and epilepsies with an emphasis on the classification and terminologies. The current therapeutic options are also highlighted briefly.
Longitudinal plasma amyloid beta in Alzheimer's disease clinical trials
Authors: Donohue Michael C. , Moghadam Setareh H. , Roe Allyson D. , Sun Chung‐Kai , Edland Steven D. , Thomas Ronald G. , Petersen Ronald C. , Sano Mary , Galasko Douglas , Aisen Paul S. , Rissman Robert A.
Published: October 2014

Introduction

Little is known about the utility of plasma amyloid beta (Aβ) in clinical trials of Alzheimer's disease (AD).

Methods

We analyzed longitudinal plasma samples from two large multicenter clinical trials: (1) donezepil and vitamin E in mild cognitive impairment (n = 405, 24 months) and (2) simvastatin in mild to moderate AD (n = 225, 18 months).

Results

Baseline plasma Aβ was not related to cognitive or clinical progression. We observed a decrease in plasma Aβ40 and 42 among apolipoprotein E epsilon 4 (APOE ε4) carriers relative to noncarriers in the mild cognitive impairment trial. Patients treated with simvastatin showed a significant increase in Aβ compared with placebo. We found significant storage time effects and considerable plate‐to‐plate variation.

Discussion

We found no support for the utility of plasma Aβ as a prognostic factor or correlate of cognitive change. Analysis of stored specimens requires careful standardization and experimental design, but plasma Aβ may prove useful in pharmacodynamic studies of antiamyloid drugs.