bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct Observation of Atomic Dynamics and Silicon Doping at a Topological Defect in Graphene
Authors: Yang Zhiqing , Yin Lichang , Lee Jaekwang , Ren Wencai , Cheng Hui‐Ming , Ye Hengqiang , Pantelides Sokrates T. , Pennycook Stephen J. , Chisholm Matthew F.
Published: July 2014

Chemical decoration of defects is an effective way to functionalize graphene and to study mechanisms of their interaction with environment. We monitored dynamic atomic processes during the formation of a rotary Si trimer in monolayer graphene using an aberration‐corrected scanning‐transmission electron microscope. An incoming Si atom competed with and replaced a metastable C dimer next to a pair of Si substitutional atoms at a topological defect in graphene, producing a Si trimer. Other atomic events including removal of single C atoms, incorporation and relocation of a C dimer, reversible CC bond rotation, and vibration of Si atoms occurred before the final formation of the Si trimer. Theoretical calculations indicate that it requires 2.0 eV to rotate the Si trimer. Our real‐time results provide insight with atomic precision for reaction dynamics during chemical doping at defects in graphene, which have implications for defect nanoengineering of graphene.
Palladium‐Catalyzed Oxidative Arylating Carbocyclization of Allenynes: Control of Selectivity and Role of H2O
Authors: Bartholomeyzik Teresa , Mazuela Javier , Pendrill Robert , Deng Youqian , Bäckvall Jan‐E.
Published: July 2014

Highly selective protocols for the carbocyclization/arylation of allenynes using arylboronic acids are reported. Arylated vinylallenes are obtained with the use of BF3⋅Et2O as an additive, whereas addition of water leads to arylated trienes. These conditions provide the respective products with excellent selectivities (generally >97:3) for a range of boronic acids and different allenynes. It has been revealed that water plays a crucial role for the product distribution.
Chemical Synthesis of Syndecan‐3 Glycopeptides Bearing Two Heparan Sulfate Glycan Chains
Authors: Yoshida Keisuke , Yang Bo , Yang Weizhun , Zhang Zeren , Zhang Jicheng , Huang Xuefei
Published: July 2014

Despite the ubiquitous presence of proteoglycans in mammalian systems, methodologies to synthesize this class of glycopeptides with homogeneous glycans are not well developed. Herein, we report the first synthesis of a glycosaminoglycan family glycopeptide containing two different heparan sulfate chains, namely the extracellular domain of syndecan‐3. With the large size and tremendous structural complexity of these molecules, multiple unexpected obstacles were encountered during the synthesis, including high sensitivity to base treatment and the instability of glycopeptides with two glycan chains towards catalytic hydrogenation conditions. A successful strategy was established by constructing the partially deprotected single glycan chain containing glycopeptides first, followed by union of the glycan‐bearing fragments and cleavage of the ester‐type protecting groups. This work lays the foundation for preparing other members of this important class of molecules.
Nanomechanical properties of poly(trimethylene malonate) and poly(trimethylene itaconate) during hydrolytic degradation
Authors: Eyiler Ersan , Chu I.‐W. , Rowe Mathew D. , Walters Keisha B.
Published: July 2014

The aim of this work was to evaluate surface mechanical properties of two bioplastics, poly(trimethylene malonate) (PTM) and poly(trimethylene itaconate) (PTI), during hydrolytic degradation. Renewable resource‐based PTM and PTI were synthesized from 1,3‐propanediol (PDO), malonic acid (MA), and itaconic acid (IA) via melt polycondensation. The hydrolytic degradation was performed in deionized (DI) water (pH 5.4) at room temperature. Morphology and surface mechanical properties at the nanoscale were monitored by atomic force microscopy (AFM) using a quantitative nanomechanical property mapping mode as a function of degradation time. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to show shifted phase transitions depending on the degradation. DSC studies showed hydrolytic degradation induced crystallinity for PTI. After degradation for one week, the degree of crystallinity had significantly increased, and the elastic modulus of PTI had decreased by 58%. PTM was found to be hygroscopic. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41069.
Mechanical and thermal properties of novel rubber‐toughened epoxy blend prepared by in situ pre‐crosslinking
Authors: Zhou Heng‐Shi , Song Xiao‐Xue , Xu Shi‐Ai
Published: July 2014

A novel method is used for preparing liquid rubber‐toughened epoxy blend, in which an initiator was added to the liquid rubber–epoxy mixture to initiate crosslinking reaction of liquid rubber, and then curing agent was added to form the thermoset. Two epoxy blends with carboxyl‐terminated butadiene‐acrylonitrile copolymers were prepared using traditional and novel methods respectively. Results indicated that the novel rubber‐toughened epoxy blend exhibited much better mechanical properties than its traditional counterpart. The morphologies of the blends were explored by transmission electron microscopy (TEM), it was revealed that the use of the novel method formed a local interpenetrating network structure in the blend, which substantially improved the interfacial adhesion. The impact fracture surfaces of the two blends were observed by scanning electron microscopy (SEM) to explore the toughening mechanism, it was found that crack pinning was the major toughening mechanism for the novel rubber‐toughened epoxy blend. Dynamic mechanical analysis (DMA) was applied to determine the Tg values of the blends, which were found to be close. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 41110.
Ammonium nitrate and iron nutrition effects on some nitrogen assimilation enzymes and metabolites in Spirulina platensis
Authors: Esen Merve , Ozturk Urek Raziye
Published: July 2014

The effect of various concentrations of ammonium nitrate (5–60 mM), an economical nitrogen source, on the growth, nitrate–ammonium uptake rates, production of some pigments and metabolites, and some nitrogen assimilation enzymes such as nitrate reductase (NR), nitrite reductase (NiR), glutamine synthetase (GS), and glutamate synthase (GOGAT) in Spirulina platensis (Gamont) Geitler was investigated. Ten millimolars of ammonium nitrate stimulated the growth, production of pigments and the other metabolites, and enzyme activities, whereas 30 and 60 mM ammonium nitrate caused inhibition. In the presence of 10 mM ammonium nitrate, different concentrations of iron were tried in the growth media of S. platensis. After achieving the best growth, levels of metabolite and pigment production, and enzyme activities in the presence of 10 mM ammonium nitrate as a nitrogen source, different iron concentrations (10–100 µM) were tried in the growth medium of S. platensis. The highest growth, pigment and metabolite levels, and enzyme activities were determined in the medium containing 50 µM iron and 10 mM ammonium nitrate. In this optimum condition, the highest dry biomass level, chlorophyll a, and pyruvate contents were obtained as 55.42 ± 3.8 mg mL−1, 93.114 ± 7.9 µg g−1, and 212.5 ± 18.7 µg g−1, respectively. The highest NR, NiR, GS, and GOGAT activities were 67.16 ± 5.1, 777.92 ± 52, 0.141 ± 0.01, and 44.45 ± 3.6, respectively. Additionally, 10 mM ammonium nitrate is an economical and efficient nitrogen source for nitrogen assimilation of S. platensis, and 50 µM iron is optimum for the growth of S. platensis.
Postmastectomy radiation therapy for T3N0: A SEER analysis
Authors: Johnson Matthew E. , Handorf Elizabeth A. , Martin Jeffrey M. , Hayes Shelly B.
Published: July 2014

BACKGROUND

There is conflicting evidence regarding the benefit of postmastectomy radiation therapy (PMRT) for pathologic stage T3N0M0 breast cancers. We analyzed data from the Surveillance, Epidemiology, and End Results (SEER) database to investigate the benefit of PMRT in this patient population.

METHODS

We queried the SEER database for T3N0M0 breast cancer patients diagnosed from 2000 to 2010 who underwent modified radical mastectomy. We excluded males, patients with unknown radiation timing/type, other primary tumors, and survival <6 months. A total of 2525 patients were included in the analysis. We performed univariate and multivariate statistical analysis using chi‐square tests, log‐rank tests, and Cox proportional hazards regression. The primary endpoints were overall survival (OS) and cancer‐specific survival (CSS).

RESULTS

Of the 2525 patients identified, 1063 received PMRT. The median follow‐up was 56 months (range, 6‐131 months). On univariate analysis, PMRT improved OS (76.5% vs 61.8%, P<.01) and CSS (85.0% vs 82.4%, P<.01) at 8 years. The use of PMRT remained significant on multivariate analysis: PMRT improved OS (hazard ratio 0.63, P<.001) and CSS (hazard ratio 0.77, P = .045). Low tumor grade (P<.01) and marital status of “married” (P = .01) also was a predictor of improved CSS on multivariate analysis.

CONCLUSIONS

PMRT was associated with significant improvements in both CSS and OS in patients with T3N0M0 breast cancers treated with modified radical mastectomy from 2000 to 2010. PMRT should be strongly considered in T3N0M0 patients.

Postmastectomy radiation therapy is associated with significant improvements in overall and cause‐specific survival in patients with T3N0M0 breast cancers treated with modified radical mastectomy from 2000 to 2010 in the SEER database. Postmastectomy radiation therapy should be strongly considered for patients who have T3N0M0 tumors. Cancer 2014;120:3569–3574. © 2014 American Cancer Society.
Stacking of Benzene with Metal Chelates: Calculated CCSD(T)/CBS Interaction Energies and Potential‐Energy Curves
Authors: Malenov Dušan P. , Ninković Dragan B. , Sredojević Dušan N. , Zarić Snežana D.
Published: July 2014

Accurate values for the energies of stacking interactions of nickel‐ and copper‐based six‐membered chelate rings with benzene are calculated at the CCSD(T)/CBS level. The results show that calculations made at the ωB97xD/def2‐TZVP level are in excellent agreement with CCSD(T)/CBS values. The energies of [Cu(C3H3O2)(HCO2)] and [Ni(C3H3O2)(HCO2)] chelates stacking with benzene are −6.39 and −4.77 kcal mol−1, respectively. Understanding these interactions might be important for materials with properties that are dependent on stacking interactions.
Ecohydrological flow networks in the subsurface
Authors: Band L. E. , McDonnell J. J. , Duncan J. M. , Barros A. , Bejan A. , Burt T. , Dietrich W. E. , Emanuel R. E. , Hwang T. , Katul G. , Kim Y. , McGlynn B. , Miles B. , Porporato A. , Scaife C. , Troch P. A.
Published: July 2014

Preferential flow in hillslope systems through subsurface networks developed from a range of botanical, faunal and geophysical processes have been observed and inferred for decades and may provide a large component of the bulk transport of water and solutes. However, our dominant paradigm for understanding and modelling hillslope hydrologic processes is still based on the Darcy–Richards matric flow framework, now with a set of additional methods to attempt to reproduce some of the aggregate function of the two‐phase system of network and matrix flow. We call for a community effort to design and implement a set of well planned experiments in different natural and constructed hillslopes, coupled with the development of new theory and methods to explicitly incorporate and couple the co‐evolution of subsurface flow networks as intrinsic components of hydrological, ecological and geomorphic systems. This is a major community challenge that can now benefit from new experimental infrastructure, renewal of older infrastructure and recent advances in sensor systems and computational capacity but will also require a sustained and organized interdisciplinary approach. Copyright © 2014 John Wiley & Sons, Ltd.
Synergistic Effect of Lithium Perchlorate and Sodium Hydroxide in the Preparation of Electrochemically Treated Pencil Graphite Electrodes for Selective and Sensitive Bisphenol A Detection in Water Samples
Authors: Özcan Ali
Published: July 2014

In this study, pencil graphite electrodes were activated electrochemically in the presence of different supporting electrolytes and used for the selective and sensitive determination of bisphenol A (BPA) in water samples. Synergistic effects of both LiClO4 and NaOH supporting electrolytes on the performance of the electrochemically treated pencil graphite electrode (ETPGE) were demonstrated in the oxidation of BPA. The electrochemical behavior of BPA on the ETPGE showed two irreversible oxidation peaks at 0.744 V and 0.877 V (vs. SCE). The detection limit was determined to be 3.1 nM. This single‐use electrode is a very promising candidate to overcome the passivation problems arising from the oxidation of BPA. The analytical application of the ETPGE was performed in tap and river water samples.
Palladium Particles‐Impregnated Natural Phosphate Electrodes for Electrochemical Determination of Mercury in Ambient Water Samples
Authors: El Aroui F. , Lahrich S. , Farahi A. , Achak M. , El Gaini L. , Bakasse M. , Bouzidi A. , El Mhammedi M. A.
Published: July 2014

We present here a simple procedure for the determination of mercury(II) using differential pulse anodic stripping voltammetry (DPASV) at palladium particles‐impregnated natural phosphate modified carbon paste electrodes (Pd‐NP‐CPE). The surface of modified electrode was characterized using SEM, infrared spectroscopy, X‐ray diffraction and electrochemical analysis. All experimental variables involved in the voltammetric stripping method were optimized. The detection limit was found to be 4.99×10−8 mol L−1 (S/N=3) that is not different to the permitted value for Hg(II) in water reported by the Environmental Protection Agency (EPA). The proposed electrode exhibits good applicability for monitoring Hg(II) in tap and wastewater.
Analysis and differentiation of paper samples by capillary electrophoresis and multivariate analysis
Authors: Fernández de la Ossa Ma Ángeles , Ortega‐Ojeda Fernando , García‐Ruiz Carmen
Published: July 2014

This work reports an investigation for the analysis of different paper samples using CE with laser‐induced detection. Papers from four different manufactures (white‐copy paper) and four different paper sources (white and recycled‐copy papers, adhesive yellow paper notes and restaurant serviettes) were pulverized by scratching with a surgical scalpel prior to their derivatization with a fluorescent labeling agent, 8‐aminopyrene‐1,3,6‐trisulfonic acid. Methodological conditions were evaluated, specifically the derivatization conditions with the aim to achieve the best S/N signals and the separation conditions in order to obtain optimum values of sensitivity and reproducibility. The best conditions, in terms of fastest, and easiest sample preparation procedure, minimal sample consumption, as well as the use of the simplest and fastest CE‐procedure for obtaining the best analytical parameters, were applied to the analysis of the different paper samples. The registered electropherograms were pretreated (normalized and aligned) and subjected to multivariate analysis (principal component analysis). A successful discrimination among paper samples without entanglements was achieved. To the best of our knowledge, this work presents the first approach to achieve a successful differentiation among visually similar white‐copy paper samples produced by different manufactures and paper from different paper sources through their direct analysis by CE‐LIF and subsequent comparative study of the complete cellulose electropherogram by chemometric tools.
Next generation sequencing challenges in the analysis of cardiac sudden death due to arrhythmogenic disorders
Authors: Brion Maria , Blanco‐Verea Alejandro , Sobrino Beatriz , Santori Montserrat , Gil Rocio , Ramos‐Luis Eva , Martinez Marina , Amigo Jorge , Carracedo Angel
Published: July 2014

Inherited arrhythmogenic disorders is a relatively common cause of cardiac sudden death in young people. Diagnosis has been difficult so far due to the genetic heterogeneity of the disease. Next generation sequencing (NGS) is offering a new scenario for diagnosis. The purpose of our study was to validate NGS for the analysis of twenty‐eight genes known to be associated with inherited arrhythmogenic disorders and therefore with sudden cardiac death. SureSelect hybridization was used to enrich DNA from 53 samples, prior to be sequenced with the SOLID™ System of Life Technologies. Depth of coverage, consistency of coverage across samples, and location of variants identified were assessed. All the samples showed a depth of coverage over 200×, except one of them discarded because of its coverage below 30×. Average percentage of target bp covered at least 20× was 96.45%. In the remaining samples, following a prioritization process 46 possible variants in 31 samples were found, of which 45 were confirmed by Sanger sequencing. After filtering variants according to their minor allele frequency in the Exome Sequencing Project 27 putative pathogenic variants in 20 samples remained. With the use of in silico tools, 13 variants in 11 samples were classified as likely pathogenic. In conclusion, NGS allowed us to accurately detect arrhythmogenic disease causing mutations in a fast and cost‐efficient manner that is suitable for daily clinical and forensic practice of genetic testing of this type of disorders.
Interactions between CdTe quantum dots and DNA revealed by capillary electrophoresis with laser‐induced fluorescence detection
Authors: Stanisavljevic Maja , Chomoucka Jana , Dostalova Simona , Krizkova Sona , Vaculovicova Marketa , Adam Vojtech , Kizek Rene
Published: July 2014

Quantum dots (QDs) are one of the most promising nanomaterials, due to their size‐dependent characteristics as well as easily controllable size during the synthesis process. They are promising label material and their interaction with biomolecules is of great interest for science. In this study, CdTe QDs were synthesized under optimal conditions for 2 nm size. Characterization and verification of QDs synthesis procedure were done by fluorimetric method and with CE. Afterwards, QDs interaction with chicken genomic DNA and 500 bpDNA fragment was observed employing CE‐LIF and gel electrophoresis. Performed interaction relies on possible matching between size of QDs and major groove of the DNA, which is approximately 2.1 nm.
Dual‐wavelength recording, a simple algorithm to eliminate interferences due to UV‐absorbing substances in capillary electrophoresis
Authors: Seaux Liesbeth , Van Houcke Sofie , Dumoulin Els , Fiers Tom , Lecocq Elke , Delanghe Joris R.
Published: July 2014

Analytical interferences have been described due to the presence of various exogenous UV‐absorbing substances in serum. Iodine‐based X‐ray contrast agents and various antibiotics have been reported to interfere with interpretation of serum protein pherograms, resulting in false diagnosis of paraproteinemia. In the present study, we have explored the possibility of measuring UV absorbance at two distinct wavelengths (210 and 246 nm) to distinguish between true and false paraproteins on a Helena V8 clinical electrophoresis instrument. This study demonstrates that most substances potentially interfering with serum protein electrophoresis show UV‐absorption spectra that are distinct from those of serum proteins. Scanning at 246 nm allows detection of all described interfering agents. Comparing pherograms recorded at both wavelengths (210 and 246 nm) enables to distinguish paraproteins from UV‐absorbing substances. In case of a true paraprotein, the peak with an electrophoretic mobility in the gamma‐region decreases, whereas the X‐ray contrast media and antibiotics show an increased absorption when compared to the basic setting (210 nm). The finding of iodine‐containing contrast media interfering with serum protein electrophoresis is not uncommon. In a clinical series, interference induced by contrast media was reported in 54 cases (of 13 237 analyses), corresponding with a prevalence of 0.4%. In the same series, 1631 true paraproteins (12.3%) were detected. Implementation of the proposed algorithm may significantly improve the interpretation of routine electrophoresis results. However, attention should still be paid to possible interference due to presence of atypical proteins fractions (e.g., tumor markers, C3).
An Experimental Study on Three General Interface Layout Designs for Chemical Process Plants
Authors: Liu C. J. , Lin Y. , Teng H. , Wang Z. D. , Zhang W. J.
Published: July 2014

The human‐machine interface design is not a new problem; however, existing knowledge appears to be focused either on interface conceptual design, which determines what information at what time needs to be displayed, or on interface detailed design, which determines the form of display elements. This article presents a study on interface layout design. Three interface layout designs were proposed based on the proximity compatibility priniciple, which were on the same interface conceptual design. In particular, the first interface layout design is with the highest degree of proximity cognition and the second and third with a reduced degree of proximity cognition. They are called sophisticated, semisophisticated, and nonsophisticated interfaces, respectively. An experiment with a simple process plant was conducted to understand user behaviors on the three interfaces. It is noted that in order to provide an unbiased comparative evaluation of these interfaces the same application problem and similar look‐and‐feel forms of interfaces were designed. In the experiment, three general classes of tasks were considered, namely, normal control operation, fault detection (or monitoring), and fault diagnosis. Two categories of measures were used: the performance measure and the subjective measure. The major results obtained from the experiment are 1) the nonsophisticated interface is the best for fault detections in terms of performance measure; besides, this interface has the lowest mental workload for fault detection; 2) the sophisticated interface is the best for normal operation in terms of performance measure; 3) there appears no significant difference for fault diagnosis in terms of performance measures for all these three interfaces; 4) for normal operation and fault diagnosis, the mental workloads for the three interfaces have no significant difference. Overall, the experiment suggests that the nonsophisticated interface be used in practice with additional two reasons: 1) most of time in the chemical process plant today is the fault detection or operation monitoring task, and 2) it is relatively easier for the nonsophisticated interface to adapt to changes in the chemical process plant design, which are common in today's manufacturing environments.
Swainsonine Induces Caprine Luteal Cells Apoptosis via Mitochondrial‐Mediated Caspase‐Dependent Pathway
Authors: Li Wei , Huang Yong , Zhao Xiaomin , Zhang Wenlong , Dong Feng , Du Qian , Tong Dewen
Published: July 2014

Swainsonine (SW) is an indolizidine alkaloid isolated from a number of poisonous plants. We have previously reported that SW inhibited luteal cell progesterone production by inducing caprine luteal cell apoptosis in vitro; however, the molecular mechanism of this phenomenon remains unclear. In this study, SW‐treated luteal cells showed apoptosis characteristics, including nuclear fragmentation, DNA ladder formation, and phosphatidylserine externalization. Further studies showed that SW activated caspase‐9 and caspase‐3, which subsequently cleaved poly(ADP‐ribose) polymerase. SW also increased in Bax/BcL‐2 ratios, promoted Bax translocation from the cytosol to mitochondria, and triggered the release of cytochrome c from mitochondria into the cytoplasm. However, Fas and Fas ligand induction or caspase‐8 activity did not appear any significant changes. Additional analysis also showed that pan‐caspase inhibitor, caspase‐9 inhibitor, or caspase‐3 inhibitor almost completely protected the cells from SW‐induced apoptosis, but not caspase‐8 inhibitor. Overall, these data demonstrated that SW induced luteal cells apoptosis through a mitochondrial‐mediated caspase‐dependent pathway.
Generalized conditioned reinforcement with pigeons in a token economy
Authors: DeFulio Anthony , Yankelevitz Rachelle , Bullock Christopher , Hackenberg Timothy D.
Published: July 2014

Six pigeons were studied in a token economy in which tokens could be produced and exchanged for food on one side of an experimental chamber and for water on the opposite side of the chamber. Responses on one key produced tokens according to a token‐production fixed ratio (FR) schedule. Responses on a second key produced an exchange period during which tokens were exchanged for water or food. In Experiment 1a, food tokens could be earned and exchanged under restricted food budgets, and water tokens could be earned and exchanged under water restricted budgets. In Experiment 1b, a third (generalized) token type could be earned and exchanged for either food or water under water restricted budgets. Across Experiments 1a and 1b, the number of tokens accumulated prior to exchange increased as the exchange‐production schedule was increased. In Experiment 1b, pigeons produced more generalized than specific tokens, suggesting enhanced reinforcing efficacy of generalized tokens. In Experiment 2, the FR token‐production price was manipulated under water restriction and then under food restriction. Production of each token type generally declined as a function of its own price and increased as a function of the price of the alternate type, demonstrating own‐price and cross‐price elasticity. Production of food and water tokens often changed together, indicating complementarity. Production of specific and generalized tokens changed in opposite directions, indicating substitutability. This is the first demonstration of sustained generalized functions of tokens in nonhumans, and illustrates a promising method for exploring economic contingencies in a controlled environment.
Effect of wine processing and acute blood stasis on the serum pharmacochemistry of rhubarb: A possible explanation for processing mechanism
Authors: Wang Min , Fu Jinfeng , Lv Mengying , Tian Yuan , Xu Fengguo , Song Rui , Zhang Zunjian
Published: July 2014

As a specific item mentioned in traditional Chinese medicine theory, processing can fulfill different requirements of therapies. Crude and wine‐processed rhubarbs are used as drastic and mild laxatives, respectively. In this study, a practical method based on ultra‐fast liquid chromatography coupled with diode‐array detection and ion trap time‐of‐flight mass spectrometry was developed to screen and analyze multiple absorbed bioactive components and metabolites in the serum of both normal and acute blood stasis rats after oral administration of crude or wine‐processed rhubarbs. A total of 16 compounds, mainly including phase II metabolites, were tentatively identified. Possible explanations for the processing‐induced changes in pharmacological effects of traditional Chinese medicines were first explored at serum pharmacochemistry level.
Phenoxysalicylaldimine‐Bearing Chromium(III) Precatalysts for Ethylene Polymerization
Authors: Yankey Margaret , Obuah Collins , Darkwa James
Published: July 2014

A series of discrete chromium(III) precatalysts, {[Cr(κ3‐L1)] (1a.7H2O), {[Cr(κ3‐L2)] (2a.5H2O), {[Cr(κ3‐L3)] (3a.6H2O), {[Cr(κ3‐L4)] (4a.10H2O), {[Cr(κ3‐L5)] (5a.4H2O) and in‐situ‐generated chromium(III) precatalysts {[Cr(κ3‐L1)] (1b), {[Cr(κ3‐L2)] (2b), {[Cr(κ3‐L3)] (3b), {[Cr(κ3‐L4)] (4b), {[Cr(κ3‐L5)] (5b) bearing 2,4‐di‐tert‐butyl‐6‐{[2‐(1H‐imidazol‐4‐yl)‐ethylimino]‐methyl}‐phenol (L1), 2,4‐di‐tert‐butyl‐6‐{[2‐RR‐pyrazol‐1‐yl‐ethylimino]‐methyl}‐phenol, R = H (L2), Me (L3), Ph (L4), and 2,4‐di‐tert‐butyl‐6‐{[2‐pyrid‐2‐yl‐ethylimino]‐methyl}‐phenol (L5) are developed. The discrete precatalysts are characterized by IR spectroscopy, elemental analysis, and mass spectrometry. The in‐situ‐generated precatalysts afford a one‐step process for screening chromium(III) complexes as ethylene polymerization catalysts. Upon activation with EtAlCl2, both types of precatalysts exhibit high catalytic activities up to 1.71 × 105 g mol(Cr)−1 h−1 for the formation of high‐density polyethylene with molecular weights as high as 3.48 × 103 g mol−1. While the discrete precatalysts produce monomodal active catalysts at all conditions, the in‐situ‐generated precatalysts produce either monomodal or bimodal active catalysts, suggesting that, at certain conditions, two active catalysts are produced in the in situ reactions.

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New shrimp IgE‐binding proteins involved in mite‐seafood cross‐reactivity
Authors: Gámez Cristina , Zafra M. Paz , Boquete Manuel , Sanz Verónica , Mazzeo Carla , Ibáñez M. Dolores , Sánchez‐García Silvia , Sastre Joaquín , del Pozo Victoria
Published: July 2014

Scope

Shrimp is a seafood consumed worldwide and the main cause of severe allergenic reactions to crustaceans. Seafood allergy has been related to mite sensitization, mainly mediated by tropomyosin, but other proteins could be involved. The aim of the study was to identify new shrimp allergens implicated in mite‐seafood cross‐reactivity (CR) in two different climate populations: dry and humid climates.

Methods and results

Shrimp and mite IgE‐binding profiles of patients from continental dry and humid climates were analyzed by immunoblotting, and the most frequently recognized Solenocera melantho shrimp proteins were identified by MS as α‐actinin, β‐actin, fructose biphosphate aldolase, arginine kinase, sarcoplasmic calcium‐binding protein, and ubiquitin. Using inhibition immunoblot assays, we demonstrate that tropomyosin and ubiquitin were responsible for mite‐seafood CR from both climates; but also α‐actinin and arginine kinase are implicated in dry‐ and humid‐climate populations, respectively. Reciprocal inhibition assays demonstrated that mites are the primary sensitizer in humid‐climate, as shrimp is in continental dry‐climate population.

Conclusion

Several new shrimp allergens have been identified and should be considered in the diagnosis and treatment of shrimp allergy and mite‐seafood CR. Differences in mite‐seafood CR were founded to be based on the climate.
Effects of kaolin on the thermal stability and flame retardancy of polypropylene composite
Authors: Zhang Sheng , Jiang Peng , Liu Xishan , Gu Xiaoyu , Zhao Qian , Hu Zhongwu , Tang Wufei
Published: July 2014

Kaolin clay was introduced into an intumescent flame retardant (IFR) system containing ammonium polyphosphate as an acid source and pentaerythritol as a carbonization agent in order to improve the thermal stability and flame retardancy of polypropylene (PP) composite. The flame retardancy and smoke suppression was evaluated by the limiting oxygen index, vertical burning UL‐94, and cone calorimeter (CONE) tests. The limiting oxygen index value was increased from 30 to 33 at the presence of 2 phr kaolin. The peak heat release rate value decreased from 1002 kW/m2 of neat PP to 318 kW/m2 of PP/40 phr IFR and then to 222 kW/m2 of PP/38 phr IFR/2 phr kaolin. The time of the peak heat release rate was significantly prolonged after the introduction of kaolin. The morphology of char after combustion was characterized by a scanning electron microscope, and it revealed more compact char structure that was obtained at the presence of kaolin. The mechanism of kaolin on improving the retardancy and smoke suppression of PP/IFR composite was proposed on the basis of X‐ray photoelectron spectroscopy analysis. Copyright © 2014 John Wiley & Sons, Ltd.
Synthesis and dielectric properties of novel liquid crystalline triblock copolymers with cyanobiphenyl moieties and poly(n‐butyl acrylate) segments
Authors: Zhang Cuihong , Wang Dongrui , He Jin , Liang Tao , Hu Guo‐Hua , Dang Zhi‐Min
Published: July 2014

In this work, self‐assembly method was used to improve the dielectric constant of triblock copolymers. A series of ABA triblock copolymers with a defined length of poly(n‐butyl acrylate) (PBA, B block) segment and different lengths of liquid crystalline (LC) poly[11‐(4‐cyano‐4′‐biphenoxy)undecyl methacrylate] (P11CBMA, A block) segments were synthesized by using the atom transfer radical polymerization method. The well‐defined triblock copolymers P11CBMAm‐b‐PBAn‐b‐P11CBMAm possess three different B/A ratios (n = 50, m = 17, 43, 53). Due to the supramolecular cooperative motion effect, the copolymers can form worm‐like microstructure (WLC = 52.8%), cylinder‐like nanostructure with P11CBMA phase embedded in PBA matrix (WLC = 73.9%), and wide stripe structure with LC domains distributed unevenly in a continuous PBA matrix (WLC = 77.7%) after annealed at 160°C (above Ti) under N2 for 24 h, respectively. In order to study the influence of microphase separated morphology of triblock copolymer on the dielectric properties, solvent annealing was also used to develop various nanostructures. After thermal or solvent annealing, the dielectric constants of block copolymers increased dramatically while their loss factors remained the same. For different block copolymers, the dielectric constants increased with the increase of the LC block length. For diverse treatments, dielectric permittivities of samples varied widely with different nanostructures. The results show that the dielectric constants of block copolymers could be tuned by the block ratios and the self‐assembled microstructures. These findings will inspire researchers using self‐assembly method to design and develop novel flexible materials with high dielectric permittivity. Copyright © 2014 John Wiley & Sons, Ltd.
Progression from cirrhosis to cancer is associated with early ubiquitin post‐translational modifications: identification of new biomarkers of cirrhosis at risk of malignancy
Authors: Laouirem Samira , Le Faouder Julie , Alexandrov Theodore , Mestivier Denis , Léger Thibaut , Baudin Xavier , Mebarki Mouniya , Paradis Valérie , Camadro Jean‐Michel , Bedossa Pierre
Published: July 2014

Cirrhosis is a lesion at risk of hepatocellular carcinoma (HCC). Identifying mechanisms associated with the transition from cirrhosis to HCC and characterizing biomarkers of cirrhosis at high risk of developing into cancer are crucial for improving early diagnosis and prognosis of HCC. We used MALDI imaging to compare mass spectra obtained from tissue sections of cirrhosis without HCC, cirrhosis with HCC, and HCC, and a top‐down proteomics approach to characterize differential biomarkers. We identified a truncated form of monomeric ubiquitin lacking the two C‐terminal glycine residues, Ubi(1‐74), the level of which increased progressively, from cirrhosis without HCC to cirrhosis with HCC to HCC. We showed that kallikrein‐related peptidase 6 (KLK6) catalysed the production of Ubi(1‐74) from monomeric ubiquitin. Furthermore, we demonstrated that KLK6 was induced de novo in cirrhosis and increased in HCC in parallel with accumulation of Ubi(1‐74). We investigated in vitro the possible consequences of Ubi(1‐74) accumulation and demonstrated that Ubi(1‐74) interferes with the normal ubiquitination machinery in what is likely to be a kinetic process. Our data suggest that de novo KLK6 expression during early liver carcinogenesis may induce production of Ubi(1‐74) by post‐translational modification of ubiquitin. Given the deleterious effect of Ubi(1‐74) on protein ubiquitination and the major role of ubiquitin machinery in maintenance of cell homeostasis, Ubi(1‐74) might severely impact a number of critical cellular functions during transition from cirrhosis to cancer. Ubi(1‐74) and KLK6 may serve as markers of cancer risk in patients with cirrhosis. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd
Graphene/Silicon Heterojunction Schottky Diode for Vapors Sensing Using Impedance Spectroscopy
Authors: Fattah Ali , Khatami Saeid , Mayorga‐Martinez Carmen C. , Medina‐Sánchez Mariana , Baptista‐Pires Luis , Merkoçi Arben
Published: July 2014

A graphene(G)/Silicon(Si) heterojunction Schottky diode and a simple method that evaluates its electrical response to different chemical vapors using electrochemical impedance spectroscopy (EIS) are implemented. To study the impedance response of the device of a given vapor, relative impedance change (RIC) as a function of the frequency is evaluated. The minimum value of RIC for different vapors corresponds to different frequency values (18.7, 12.9 and 10.7 KHz for chloroform, phenol, and methanol vapors respectively). The impedance responses to phenol, beside other gases used as model analytes for different vapor concentrations are studied. The equivalent circuit of the device is obtained and simplified, using data fitting from the extracted values of resistances and capacitances. The resistance corresponding to interphase G/Si is used as a parameter to compare the performance of this device upon different phenol concentrations and a high reproducibility with a 4.4% relative standard deviation is obtained. The efficiency of the device fabrication, its selectivity, reproducibility and easy measurement mode using EIS makes the developed system an interesting alternative for gases detection for environmental monitoring and other industrial applications.
The role of nanofillers on (natural rubber)/(ethylene vinyl acetate)/clay nanocomposite in blending and foaming
Authors: Lopattananon Natinee , Julyanon Juthapat , Masa Abdulhakim , Kaesaman Azizon , Thongpin Chanchai , Sakai Tadamoto
Published: July 2014

Nanocomposite foams were fabricated from 60/40 wt% ethylene vinyl acetate (EVA)/natural rubber (NR) blends by using azodicarbonamide as a blowing agent. Two different nanofillers (sodium montmorillonite and organoclay) were employed to study their effects on foam properties. The results were also compared with conventional (china clay)‐filled foams. Transmission electron microscopy, X‐ray diffraction, scanning electron microscopy, and three‐dimensional Microfocus X‐ray computed tomography scanning analysis were performed to characterize the EVA/NR blend morphology and foam structures. The results revealed that the nanofiller acted as a blend compatibilizer. Sodium montmorillonite was more effective in compatibilization, generating better phase‐separated EVA/NR blend morphology and improving foam structure. Higher filler loading increased the specific tensile strength of rubber foams. The rubber nanocomposite foam showed superior specific tensile strength to the conventional rubber composite foam. The elastic recovery and compressive strength of the nanocomposite foams decreased with increasing filler content, whereas the opposite trend was observed for the conventional composite foams with china clay. The thermal conductivity measurement indicated that the nanofiller had better beneficial effect on thermal insulation over china clay filler. From the present study, the nanofillers played an important role in obtaining better blend morphology as compatibilizer, rather than the nucleating agent and the nanofiller content of 5 phr (parts by weight per hundred parts of rubber) was recommended for the production of EVA/NR nanocomposite foams. J. VINYL ADDIT. TECHNOL., 21:134–146, 2015. © 2014 Society of Plastics Engineers
100th anniversary of the passenger pigeon extinction: Lessons for a complex and uncertain future
Authors: Schulz John H. , Otis David L. , Temple Stanley A.
Published: July 2014

This year marks the 100th anniversary of the passenger pigeon's (Ectopistes migratorius) extinction. Our goal is to review the bird's abundance and extinction along with several valuable lessons. The tragic extinction of the passenger pigeon helped launch the modern conservation era, and it is a story providing a stark reminder of potential consequences of reactionary and ineffective management decision processes. Similar to the extinction of passenger pigeons, we suggest multiple complex and polarized issues provide modern examples of pending ecological challenges that are effectively being ignored. Using climate change as an example, it is just as easy for people today to ignore emerging environmental system changes as it was for people in the late 19th century to ignore the implications of their actions. Although we have successfully recovered many wildlife species in the past 100 years, we have important work ahead of us requiring a more comprehensive problem‐solving paradigm if we are to have a meaningful effect. © 2014 The Wildlife Society.
In vivo time‐resolved X‐ray fluorescence mapping measurements of Egeria densa immersed in Cr(VI) aqueous solution
Authors: Hayashi Hisashi
Published: July 2014

In vivo time‐resolved Cr and Ca X‐ray fluorescence (XRF) mapping measurements were performed in a laboratory over a period of 69 days on a living common aquatic plant Egeria densa that was immersed in 5 mM K2CrO4 aqueous solution. The time and spatial resolution for each time‐resolved XRF map were ~1.6 days and 1 × 1 mm2, respectively. The obtained XRF maps exhibited characteristic localized Cr and Ca areas where the XRF signals were especially strong (‘hot spots’), and this indicated the necessity of preliminary millimeter‐resolution surveying in XRF microscopy. Ca hot spots were detected prior to Cr(VI) immersion and nearly disappeared after immersion in deionized water for 2 weeks and the Cr(VI) solution for 1 week. After these immersions, a Cr hot spot was formed at approximately the same location of the missing Ca hot spot, which suggests that the original Ca‐accumulated regions were substituted for the isolation of Cr species when they were introduced. The sizes and intensity distributions of the Cr hot spots were sensitive to the Cr(VI) exposure approximately 1 week prior to each XRF measurement. This sensitivity suggests potential applications of E. densa as a Cr(VI) biomonitor in aquatic environments. Copyright © 2014 John Wiley & Sons, Ltd.
Besov regularity for the Stokes and the Navier‐Stokes system in polyhedral domains
Authors: Eckhardt F.
Published: July 2014

In this paper we study the regularity of solutions to the Stokes and the Navier‐Stokes system in polyhedral domains contained in ℝ3. We consider the scale Bsτ(Lτ), 1/τ = s/3 + 1/2 of Besov spaces which determines the approximation order of adaptive numerical wavelet schemes and other nonlinear approximation methods. We show that the regularity in this scale is large enough to justify the use of adaptive methods. The proofs of the main results are performed by combining regularity results in weighted Sobolev spaces with characterizations of Besov spaces by wavelet expansions.
Proximate composition of milk of the bongo (Tragelaphus eurycerus) in comparison to other African bovids and to hand‐rearing formulas
Authors: Petzinger Christina , Oftedal Olav T. , Jacobsen Krista , Murtough Katie L. , Irlbeck Nancy A. , Power Michael L.
Published: July 2014

African bovids represent a highly diverse group with divergent neonatal care strategies. The extent to which their milks reflect this diversity is poorly understood. We analyzed milk of the bongo (Tragelaphus eurycerus) to compare its composition to milks of other African bovids and to evaluate bongo milk replacement formulas. Milk samples from three individuals (0 through 300 days postpartum, n = 28) were assayed for dry matter (total solids), crude fat, crude protein, total sugar, ash, calcium, and phosphorus; gross energy was assayed on a subset of samples and compared to calculated values. Nutrient composition changed very little over the lactation period except for day 0 (colostrum) and the last sample (day 300). Bongo milk (days 6–286) contained (mean ± SEM): 28.1 ± 0.7% dry matter (71.9 ± 0.7% water), 12.3 ± 0.6% fat, 10.6 ± 0.3% crude protein, 3.6 ± 0.1% sugar, 1.05 ± 0.03% ash, 0.26 ± 0.01% calcium, 0.16 ± 0.01% phosphorus, and a GE of 1.88 ± 0.06 kcal/g. The protein content of bongo milk accounts for 33% of energy. High protein energy appears to be typical of Tragelaphines and of African bovids that utilize a “hider” system of postnatal care. The stability of milk composition until day 300 suggests complete weaning may not occur until 9 months rather than at 6 months of age, as commonly assumed. None of the milk replacement formulas previously used for bongos was well matched to bongo milk composition; therefore, a new milk replacement formula is proposed. Zoo Biol. 33:305–313, 2014. © 2014 Wiley Periodicals, Inc.
The sulcus line of the trochlear groove is more accurate than Whiteside’s Line in determining femoral component rotation
Authors: Talbot Simon , Dimitriou Pandelis , Radic Ross , Zordan Rachel , Bartlett John
Published: July 2014

Purpose

The sulcus line (SL) is a three-dimensional curve produced from multiple points along the trochlear groove. Whiteside’s Line, also known as the anteroposterior axis (APA), is derived from single anterior and posterior points. The purposes of the two studies presented in this paper are to (1) assess the results from the clinical use of the SL in a large clinical series, (2) measure the SL and the APA on three-dimensional CT reconstructions, (3) demonstrate the effect of parallax error on the use of the APA and (4) determine the accuracy of an axis derived by combining the SL and the posterior condylar axis (PCA).

Methods

In the first study, we assessed the SL using a large, single surgeon series of consecutive patients undergoing primary total knee arthroplasties. The post-operative CT scans of patients (n = 200) were examined to determine the final rotational alignment of the femoral component. In the second study, measurements were taken in a series of 3DCT reconstructions of osteoarthritic knees (n = 44).

Results

The mean position of the femoral component in the clinical series was 0.6° externally rotated to the surgical epicondylar axis, with a standard deviation of 2.9° (ranges from −7.2° to 6.7°). On the 3DCT reconstructions, the APA (88.2° ± 4.2°) had significantly higher variance than the SL (90.3° ± 2.7°) (F = 5.82 andp = 0.017). An axis derived by averaging the SL and the PCA+3° produced a significant decrease in both the number of outliers (p = 0.03 vs. PCA andp = 0.007 vs. SL) and the variance (F = 6.15 andp = 0.015 vs. SL). The coronal alignment of the SL varied widely relative to the mechanical axis (0.4° ± 3.8°) and the distal condylar surface (2.6° ± 4.3°).

Conclusions

The multiple points used to determine the SL confer anatomical and geometrical advantages, and therefore, it should be considered a separate rotational landmark to the APA. These findings may explain the high degree of variability in the measurement of the APA which is documented in the literature. Combining a geometrically correct SL and the PCA is likely to further improve accuracy.
Can Pro-Marriage Policies Work? An Analysis of Marginal Marriages
Authors: Frimmel Wolfgang , Halla Martin , Winter-Ebmer Rudolf
Published: July 2014

Policies to promote marriage are controversial, and it is unclear whether they are successful. To analyze such policies, one must distinguish between a marriage that is created by a marriage-promoting policy (marginal marriage) and a marriage that would have been formed even in the absence of a state intervention (average marriage). We exploit the suspension of a cash-on-hand marriage subsidy in Austria to examine the differential behavior of marginal and average marriages. The announcement of an impending suspension of this subsidy led to an enormous marriage boom among eligible couples that allows us to locate marginal marriages. Applying a difference-in-differences approach, we show that marginal marriages are surprisingly as stable as average marriages but produce fewer children, children later in marriage, and children who are less healthy at birth.