bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanical tension applied to substrate films specifies location of neuritogenesis and promotes major neurite growth at the expense of minor neurite development
Authors: Feng Zhang‐Qi , Franz Eric W. , Leach Michelle K. , Winterroth Frank , White Christina M. , Rastogi Arjun , Gu Zhong‐Ze , Corey Joseph M.
Published: December 2015

One obstacle in neural repair is facilitating axon growth long enough to reach denervated targets. Recent studies show that axonal growth is accelerated by applying tension to bundles of neurites, and additional studies show that mechanical tension is critical to all neurite growth. However, no studies yet describe how individual neurons respond to tensile forces applied to cell bodies and neurites simultaneously; neither do any test motor neurons, a phenotype critical to neural repair. Here we examine the growth of dissociated motor neurons on stretchable substrates. E15 spinal motor neurons were cultured on poly‐lactide‐co‐glycolide films stretched at 4.8, 9.6, or 14.3 mm day−1. Morphological analysis revealed that substrate stretching has profound effects on developing motor neurons. Stretching increases major neurite length; it also forces neuritogenesis to occur nearest poles of the cell closest to the sources of tension. Stretching also reduces the number of neurites per neuron. These data show that substrate stretching affects neuronal morphology by specifying locations on the cell where neuritogenesis occurs and favoring major neurite growth at the expense of minor neurites. These results serve as a building block for development of new techniques to control and improve the growth of neurons for nerve repair purposes. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 966–974, 2016.
Metabolomics analysis reveals 6‐benzylaminopurine as a stimulator for improving lipid and DHA accumulation of Aurantiochytriumsp.
Authors: Yu Xin‐Jun , Sun Jie , Zheng Jian‐Yong , Sun Ya‐Qi , Wang Zhao
Published: December 2015

BACKGROUND

Phytohormones are chemical messengers that have a positive effect on biodiesel production of microalgae at low concentrations. However, the effect of phytohormone 6‐benzylaminopurine on lipid and docosahexaenoic acid (DHA) production in marine DHA‐producer Aurantiochytrium has never been reported. In this study, a GC‐MS‐based metabolomics method combined with a multivariate analysis is applied to reveal the metabolic mechanism of 6‐benzylaminopurine enhancing production of lipid and DHA in Aurantiochytrium sp.YLH70.

RESULTS

In total, 71 metabolites were identified by GC‐MS. The PCA model revealed that 76.9% of metabolite variation was related to 6‐benzylaminopurine treatment, and overall metabolomics profiles between the 6‐benzylaminopurine and control groups were clearly discriminated. Forty‐six metabolites identified by the PLS‐DA model were responsible for responding to 6‐benzylaminopurine. Metabolic analysis showed that 6‐benzylaminopurine could accelerate the rate of utilization of glucose in Aurantiochytrium sp. YLH70, and the metabolic flux from glycolysis, TCA cycle and mevalonate pathway to fatty acids biosynthesis was promoted. Moreover, the anti‐stress mechanism in Aurantiochytrium sp.YLH70 might be induced by 6‐benzylaminopurine.

CONCLUSION

Metabolomics is a suitable tool to discover the metabolic mechanism for improving lipid and DHA accumulation in a microorganism. 6‐benzylaminopurine has the potential to stimulate lipid and DHA production of Aurantiochytrium sp.YLH70 for industrial purposes. © 2015 The Authors. Journal of Chemical Technology & Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Interstudy repeatability of self‐gated quantitative myocardial perfusion MRI
Authors: Likhite Devavrat , Suksaranjit Promporn , Adluru Ganesh , Hu Nan , Weng Cindy , Kholmovski Eugene , McGann Chris , Wilson Brent , DiBella Edward
Published: December 2015

Purpose

To evaluate the interstudy repeatability of multislice quantitative cardiovascular magnetic resonance myocardial blood flow (MBF), myocardial perfusion reserve (MPR), and extracellular volume (ECV). A unique saturation recovery self‐gated acquisition was used for the perfusion scans.

Materials and Methods

An ungated golden angle radial turboFLASH pulse sequence was used to scan 10 subjects on two separate days on a 3T scanner. A single saturation pulse was followed by a set of four slices. Rest and hyperemia scans were acquired during free breathing. The images were reconstructed using an iterative algorithm with spatiotemporal constraints. The ungated images were retrospectively binned (self‐gated) into near‐systole and near‐diastole. Deformable registration was performed to adjust for respiratory and residual cardiac motion, and the data were fit with a Fermi model to estimate the interstudy repeatability of quantitative self‐gated MBF and MPR.

Results

The coefficient of variation (CoV) of the territorial MPR using the self‐gated near‐systole data was 18.6%. The self‐gated near‐diastole data gave less good CoV of MPR, equal to 46.2%. For MBFs, and using smaller (segmental) regions, the CoVs were 20.1% and 22.7% for the estimation of myocardial blood flow at stress and rest, respectively, using the self‐gated near‐systole data. The self‐gated near‐diastole data gave CoV = 48.6% and 44.9% for stress and rest.

Conclusion

The self‐gated free‐breathing technique for quantification of myocardial blood flow showed good repeatability for near‐systole, with results comparable to published studies on interstudy repeatability of quantitative myocardial perfusion MRI using ECG‐gating and breath‐holds. Self‐gated near‐diastole data results were less repeatable. J. Magn. Reson. Imaging 2016;43:1369–1378.
Trends in potential evapotranspiration from 1960 to 2013 for a desertification‐prone region of China
Authors: Shan Nan , Shi Zhongjie , Yang Xiaohui , Zhang Xiao , Guo Hao , Zhang Bo , Zhang Zhiyong
Published: December 2015

Evapotranspiration is a sensitive parameter for assessing climate change. It controls energy and mass exchange and is a descriptor of drought in arid‐ and semi‐arid regions. Using the Mann–Kendall (M–K) test, Sen's slope estimator, and the stepwise regression, temporal, and spatial variations in potential evapotranspiration (ET0) and its dominant factors were analysed. The analysis was based on data from 173 meteorological stations in a desertification‐prone region of China over the period from 1960 to 2013. The annual ET0 decreased prior to 1990s and increased thereafter. The majority of stations had a decreasing ET0 trend, especially in summer, in which the average slope of all stations was −2.43 mm decade−1. Analysis of determining factors showed that a decrease in wind speed was the primary factor associated with decreasing ET0. The trend magnitude of ET0 increased from −2.25 mm decade−1 to −7.43 mm decade−1 as wind speed increased, then decreased to −3.00 mm decade−1. Decreasing ET0 and increasing P in the western region led to decrease in the aridity index, suggesting a wetter climate and reduced desertification. Increasing aridity index in the eastern region reduced the vegetation cover and facilitated desertification processes, which might be a disadvantage for ecological reconstruction and desertification control. Better understanding of the response of ET0 to regional climate change may facilitate efficient use of limited water resources and establish management strategies that can combat desertification and maintain ecological security in a desertification‐prone region.
Simultaneous determination of 16 polycyclic aromatic hydrocarbons in reclaimed water using solid‐phase extraction followed by ultra‐performance convergence chromatography with photodiode array detection
Authors: Zhang Yun , Xiao Zhiyong , Lv Surong , Du Zhenxia , Liu Xiaoxia
Published: December 2015

A new fast and effective analysis method has been developed to simultaneously determine 16 polycyclic aromatic hydrocarbons in reclaimed water samples by ultra‐performance convergence chromatography with photodiode array detection and solid‐phase extraction. The parameters of ultra‐performance convergence chromatography on the separation behaviors and the crucial condition of solid‐phase extraction were investigated systematically. Under optimal conditions, the 16 polycyclic aromatic hydrocarbons could be separated within 4 min. The limits of detection and quantification were in the range of 0.4–4 and 1–10 μg/L in water, respectively. This approach has been applied to a real industrial wastewater treatment plant successfully. The results showed that polycyclic aromatic hydrocarbons were dramatically decreased after chemical treatment procedure, and the oxidation procedure was effective to remove trace polycyclic aromatic hydrocarbons.
THE KEY TRAIT SUCCESSFUL LEADERS HAVE, AND HOW TO GET IT
Authors: Halvorson Heidi Grant
Published: December 2015

Halvorson points out that a leader may indeed be trustworthy, but not be seen that way by his or her team. The problem is one of perception. People make what seems like snap judgments about you in an instant, with seemingly little information. And others can also be wrong about you, even with lots of information. Leaders may think projecting competence is the most important thing, but if they don't first convey a sense of warmth, they risk not being seen as trustworthy. “Take the time to mentally put yourself in your employees’ shoes,” she writes, “to really try to grasp their perspective.”
ARE WE RUNNING AT FULL POWER?
Authors: Smart Geoff , Street Randy , Foster Alan
Published: December 2015

A large‐scale research project by Smart, Street and Foster “discovered that three distinct things predict or explain leadership success.” They are priorities, what they refer to as ‘who,’ (the employees you hire for your organization), and relationships. “The products of these three variables,” they write, are what they have dubbed your “power score.” The research draws on such resources as their mentor Peter Drucker and Silicon Valley executive Maynard Webb. Baseline, bedrock traits like honesty are important, yet not sufficient by themselves. For instance, honesty matters, and most leaders are honest. However, this “is kind of like having lungs—necessary for leadership success but by no means sufficient.”
MINDFUL LEADERSHIP: ACHIEVING RESULTS BY MANAGING THE MIND
Authors: Hougaard Rasmus , Carter Jacqueline , Coutts Gillian
Published: December 2015

Hougaard, Carter and Coutts believe that distracted and overwhelmed leaders must contend with what they refer to as the PAID reality: “Pressured, Always‐on, Information Overloaded and Distracted.” The antidote is training attention and practicing mindfulness. It requires slowing down and “ensuring we are managing not just our activities but also our mind and remaining focused, calm and clear even in the midst of demanding business environments.” Specific instructions and tips are provided for engaging in mindfulness and thriving in what has come to be known as “The Attention Economy.” Mindfulness is about “developing high levels of self‐management by switching off the autopilot and getting in the driver's seat of your life.”
Functional Materials Design through Hydrogel Encapsulation of Inorganic Nanoparticles: Recent Developments and Challenges
Authors: Karg Matthias
Published: December 2015

The encapsulation of inorganic nanoparticles by hydrogel shells offers a promising pathway toward the design of functional building blocks for manifold applications. Hydrogel shells can be grown in a broad range of thicknesses, from a few tens to several hundreds of nanometer, allowing for encapsulation of inorganic particles with different composition, size, and shape. This gives access to a diverse toolbox of colloidal building blocks, which combine properties of the individual components in a multifunctional fashion. Hydrogel shells provide the nano­particle cores with transparent, soft, and responsive coatings which improve the colloidal stability and allow interparticle distance control in colloidal assembly. The variation of the shell dimensions gives access to controlling the fill factor and ultimately distance‐dependent effects such as plasmon resonance coupling. This article summarizes the latest efforts in the preparation of core–shell colloids with different inorganic cores and hydrogel shells of various morphologies as well as the assembly of these building blocks into functional superstructures. It is demonstrated how the level of complexity can be increased from 1D to 3D by chemical treatment of core–shell particles, i.e., core growth or core removal, and template‐free as well as template‐assisted assembly leading to isotropic and anisotropic arrangements of particles.

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Altered acetylation and succinylation profiles in Corynebacterium glutamicum in response to conditions inducing glutamate overproduction
Authors: Mizuno Yuta , Nagano‐Shoji Megumi , Kubo Shosei , Kawamura Yumi , Yoshida Ayako , Kawasaki Hisashi , Nishiyama Makoto , Yoshida Minoru , Kosono Saori
Published: December 2015

The bacterium Corynebacterium glutamicum is utilized during industrial fermentation to produce amino acids such as l‐glutamate. During l‐glutamate fermentation, C. glutamicum changes the flux of central carbon metabolism to favor l‐glutamate production, but the molecular mechanisms that explain these flux changes remain largely unknown. Here, we found that the profiles of two major lysine acyl modifications were significantly altered upon glutamate overproduction in C. glutamicum; acetylation decreased, whereas succinylation increased. A label‐free semi‐quantitative proteomic analysis identified 604 acetylated proteins with 1328 unique acetylation sites and 288 succinylated proteins with 651 unique succinylation sites. Acetylation and succinylation targeted enzymes in central carbon metabolic pathways that are directly related to glutamate production, including the 2‐oxoglutarate dehydrogenase complex (ODHC), a key enzyme regulating glutamate overproduction. Structural mapping revealed that several critical lysine residues in the ODHC components were susceptible to acetylation and succinylation. Furthermore, induction of glutamate production was associated with changes in the extent of acetylation and succinylation of lysine, suggesting that these modifications may affect the activity of enzymes involved in glutamate production. Deletion of phosphotransacetylase decreased the extent of protein acetylation in nonproducing condition, suggesting that acetyl phosphate‐dependent acetylation is active in C. glutamicum. However, no effect was observed on the profiles of acetylation and succinylation in glutamate‐producing condition upon disruption of acetyl phosphate metabolism or deacetylase homologs. It was considered likely that the reduced acetylation in glutamate‐producing condition may reflect metabolic states where the flux through acid‐producing pathways is very low, and substrates for acetylation do not accumulate in the cell. Succinylation would occur more easily than acetylation in such conditions where the substrates for both acetylation and succinylation are limited. This is the first study investigating the acetylome and succinylome of C. glutamicum, and it provides new insight into the roles of acyl modifications in C. glutamicum biology.
The particle finite element method (PFEM) in thermo‐mechanical problems
Authors: Rodriguez J. M. , Carbonell J. M. , Cante J. C. , Oliver J.
Published: December 2015

The aim of this work is to develop a numerical framework for accurately and robustly simulating the different conditions exhibited by thermo‐mechanical problems. In particular, the work will focus on the analysis of problems involving large strains, rotations, multiple contacts, large boundary surface changes, and thermal effects.

The framework of the numerical scheme is based on the particle finite element method (PFEM) in which the spatial domain is continuously redefined by a distinct nodal reconnection, generated by a Delaunay triangulation. In contrast to classical PFEM calculations, in which the free boundary is obtained by a geometrical procedure (α − shape method), in this work, the boundary is considered as a material surface, and the boundary nodes are removed or inserted by means of an error function.

The description of the thermo‐mechanical constitutive model is based on the concepts of large strains plasticity. The plastic flow condition is assumed nearly incompressible, so a u‐p mixed formulation, with a stabilization of the pressure term via the polynomial pressure projection, is proposed.

One of the novelties of this work is the use of a combination between the isothermal split and the so‐called IMPL‐EX hybrid integration technique to enhance the robustness and reduce the typical iteration number of the fully implicit Newton–Raphson solution algorithm.

The new set of numerical tools implemented in the PFEM algorithm, including new discretization techniques, the use of a projection of the variables between meshes, and the insertion and removal of points allows us to eliminate the negative Jacobians present during large deformation problems, which is one of the drawbacks in the simulation of coupled thermo‐mechanical problems.

Finally, two sets of numerical results in 2D are stated. In the first one, the behavior of the proposed locking‐free element type and different time integration schemes for thermo‐mechanical problems is analyzed. The potential of the method for modeling more complex coupled problems as metal cutting and metal forming processes is explored in the last example. Copyright © 2015 John Wiley & Sons, Ltd.
Solvent‐Dependent Facile Synthesis of Diaryl Selenides and Biphenols Employing Selenium Dioxide
Authors: Quell Thomas , Mirion Michael , Schollmeyer Dieter , Dyballa Katrin M. , Franke Robert , Waldvogel Siegfried R.
Published: December 2015

Biphenols are important structure motifs for ligand systems in organic catalysis and are therefore included in the category of so‐called “privileged ligands”. We have developed a new synthetic pathway to construct these structures by the use of selenium dioxide, a stable, powerful, and commercially available oxidizer. Our new, and easy to perform protocol gives rise to biphenols and diaryl selenides depending on the solvent employed. Oxidative treatment of phenols in acetic acid yields the corresponding biphenols, whereas conversion in pyridine results in the preferred formation of diaryl selenides. As a consequence, we were able to isolate a broad scope of novel diaryl selenides, which could act as pincer‐like ligands with further applications in organic synthesis or as ligands in transition metal catalysis.
Numerical simulation for flow‐induced stress in injection/compression molding
Authors: Cao Wei , Min Zhiyu , Zhang Shixun , Wang Tao , Jiang Jing , Li Haimei , Wang Yaming , Shen Changyu
Published: December 2015

Flow‐induced stress in compression stage is complex because compression flow combines both shear flow and extensional flow characters and involves the boundary change in melt front and compressing directions. To describe this kind of flow effectively, the theoretical model was established in terms of three‐dimensional compressible and viscoelastic fluid, and the material derivative which includes mesh moving velocity was introduced to modify the convective terms in governing and constitutive equations based on Arbitrary Lagrangian Eulerian description. The corresponding variational equations were derived via Gauss formula and the finite element method was used to discretize the flow variables with mixed elements. In order to decouple the interdependence of velocity, stress, and temperature, a new approach involves twofold iterations was proposed to solve nonlinear flow problem. A new mesh updating scheme was presented to keep consistent with compressed regions. Numerical results indicate the compression can reduce the flow‐induced stress significantly compared to conventional injection molding, increase compressing velocity enlarges flow‐induced stress, and high temperature decreases flow‐induced stress. The proposed method was verified by photoelastic pictures and measured pressures and temperatures during molding. POLYM. ENG. SCI., 56:287–298, 2016. © 2015 Society of Plastics Engineers
On‐line monitoring of chord distributions in liquid–liquid dispersions and suspension polymerizations by using the focused beam reflectance measurement technique
Authors: Poblete Israel Bernardo , Castor Carlos Alberto , Nele Marcio , Pinto José Carlos
Published: December 2015

The on‐line monitoring of the droplet/particle size distributions is very important to ensure the quality and applicability of various products in heterogeneous systems. For this reason, the main objective of the present work was to study the usage of the focused beam reflectance measurement (FBRM) technique for monitoring of liquid–liquid dispersions (styrene dispersion in aqueous solutions) and suspension polymerization of styrene. To do better understand the FBRM technique in these systems, the effects of surfactant concentrations, agitation speed and ambient light were evaluated during the in‐line monitoring of average chord lengths and chord‐length distributions (CLD) at different operation conditions in batch experiments. In addition, a preliminary investigation of the optimal probe position was conducted in the polymerization experiments. It is shown that the FBRM technique is sensitive to variations of particle sizes in the characteristic ranges of particle diameters of typical styrene suspension polymerizations, being useful for monitoring and also control applications that require the on‐line characterization of CLD in real time in liquid–liquid dispersions and polymerization systems. POLYM. ENG. SCI., 56:309–318, 2016. © 2015 Society of Plastics Engineers
BEHAVIOR ANALYTIC CONSULTATION FOR ACADEMIC REFERRAL CONCERNS
Authors: Dufrene Brad A. , Zoder‐Martell Kimberly A. , Dieringer Shannon Titus , Labrot Zachary
Published: December 2015

Applied behavior analysis provides a technology of human behavior that demonstrates great potential for improving socially important outcomes for individuals. School‐based consultation may provide a vehicle for delivering applied behavior analysis services in schools to address academic referral concerns. In this article, we propose that school‐based consultants should use the principles of applied behavior analysis as a guide for their consultation efforts. We provide the conceptual rationale for the use of applied behavior analysis as a guide for school‐based consultants and specific procedural recommendations for applying a behavior analytic approach to school‐based consultation.
Pourbaix diagrams in weakly coupled systems: a case study involving acridinol and phenanthridinol pseudobases
Authors: Walpita Janitha , Yang Xin , Khatmullin Renat , Luk Hoi Ling , Hadad Christopher M. , Glusac Ksenija D.
Published: December 2015

The thermodynamics of proton‐coupled electron transfer (PCET) in weakly coupled organic pseudobases was investigated using 2,7‐dimethyl‐9‐hydroxy‐9‐phenyl‐10‐tolyl‐9,10‐dihydroacridine (AcrOH) and 6‐phenylphenanthridinol (PheOH) as model compounds. Pourbaix diagrams for two model compounds were constructed using the oxidation potentials and the pKa values obtained, respectively, from cyclic voltammetry and photometric titrations. Our comparative study reveals the importance of having the redox active –N center closer to –OH functionality on the thermodynamics of PCET process: PheOH exhibits a wider range of pH values (pH = 2.8 to 13.3) in which both the alcohol and the corresponding alkoxy radical are expected to coexist in solution. This result indicates that a concerted mechanism is more likely to be discovered in pseudobases analogous to PheOH. The thermochemical data also indicate that the concerted PCET mechanism cannot be achieved if water is used as the proton acceptor: assuming the pKa of hydronium ions as −1.7, the PCET involving PheOH or AcrOH as proton/electron donors and water as the proton acceptor is expected to follow the stepwise ET/PT mechanism. Copyright © 2015 John Wiley & Sons, Ltd.
Magnesium in cystic fibrosis—Systematic review of the literature
Authors: Santi Maristella , Milani Gregorio P. , Simonetti Giacomo D. , Fossali Emilio F. , Bianchetti Mario G. , Lava Sebastiano A.G.
Published: December 2015

Background

The metabolism of sodium, potassium, and chloride and the acid‐base balance are sometimes altered in cystic fibrosis. Textbooks and reviews only marginally address the homeostasis of magnesium in cystic fibrosis.

Methods

We performed a search of the Medical Subject Headings terms (cystic fibrosis OR mucoviscidosis) AND (magnesium OR hypomagnes[a]emia) in the US National Library of Medicine and Excerpta Medica databases.

Results

We identified 25 reports dealing with magnesium and cystic fibrosis. The results of the review may be summarized as follows. First, hypomagnesemia affects more than half of the cystic fibrosis patients with advanced disease; second, magnesemia, which is normally age‐independent, relevantly decreases with age in cystic fibrosis; third, aminoglycoside antimicrobials frequently induce both acute and chronic renal magnesium‐wasting; fourth, sweat magnesium concentration was normal in cystic fibrosis patients; fifth, limited data suggest the existence of an impaired intestinal magnesium balance. Finally, stimulating observations suggest that magnesium supplements might achieve an improvement in respiratory muscle strength and mucolytic activity of both recombinant and endogenous deoxyribonuclease.

Conclusions

The first comprehensive review of the literature confirms that, despite being one of the most prevalent minerals in the body, the importance of magnesium in cystic fibrosis is largely overlooked. In these patients, hypomagnesemia should be sought once a year. Furthermore, the potential of supplementation with this cation deserves more attention. Pediatr Pulmonol. 2016;51:196–202. © 2015 Wiley Periodicals, Inc.
Protein purification and crystallization artifacts: The tale usually not told
Authors: Niedzialkowska Ewa , Gasiorowska Olga , Handing Katarzyna B. , Majorek Karolina A. , Porebski Przemyslaw J. , Shabalin Ivan G. , Zasadzinska Ewelina , Cymborowski Marcin , Minor Wladek
Published: December 2015

The misidentification of a protein sample, or contamination of a sample with the wrong protein, may be a potential reason for the non‐reproducibility of experiments. This problem may occur in the process of heterologous overexpression and purification of recombinant proteins, as well as purification of proteins from natural sources. If the contaminated or misidentified sample is used for crystallization, in many cases the problem may not be detected until structures are determined. In the case of functional studies, the problem may not be detected for years. Here several procedures that can be successfully used for the identification of crystallized protein contaminants, including: (i) a lattice parameter search against known structures, (ii) sequence or fold identification from partially built models, and (iii) molecular replacement with common contaminants as search templates have been presented. A list of common contaminant structures to be used as alternative search models was provided. These methods were used to identify four cases of purification and crystallization artifacts. This report provides troubleshooting pointers for researchers facing difficulties in phasing or model building.
Work function and AC operating gas‐sensitive films based on quaternary chalcogenides
Authors: Tsiulyanu D. , Ciobanu M. , Liess H.‐D.
Published: December 2015

A study of quaternary alloys of As–S–Ge–Te was performed in order to assess their use in future gas sensors operating at room temperature. To elucidate the effect of tellurium, the quaternary compositions and , with increasing concentration of Te have been considered along with pure tellurium films. SEM, AFM, and X‐ray analysis have shown that the nature of the films was predominantly amorphous. To overcome the sensing disadvantage of DC chalcogenide‐based sensors due to small signal/noise ratio, gas‐sensing measurements were performed using both potential difference (Kelvin probe) and AC methods. The work‐function measurements showed that the amorphous chalcogenides in question are suitable materials for the detection of small concentrations of NO2. The sensing mechanism of NO2 is explained by “strong” chemisorptions via interaction of adsorbed species with lone‐pair electrons, which form the upper part of the valence band of chalcogenide semiconductors. The chemisorption of NO2 molecules results in increases in both work‐function change ΔΦ > 0 and electrical conductivity Δσ > 0 because of the additional charging of the surface and band bending. The impedance spectra, being strongly influenced by gaseous environment, depend on material composition and film microstructure. The frequency‐dependent impedance sensitivity to nitrogen dioxide denotes the competitive influence of carrier transport via states of allowed bands, hopping between localized states in the extended band tails and tunneling (variable‐range hopping) between localized states close to the Fermi level. Impedance sensitivity, being maximal for amorphous , is assumed to be controlled by competition of these charge‐transport mechanisms.
Reliability Analysis of Multistage Interconnection Networks
Authors: Rajkumar S. , Goyal Neeraj Kumar
Published: December 2015

Multistage interconnection networks (MINs) are widely used for reliable data communication in tightly coupled large‐scale multiprocessor systems. Reliability evaluation of interconnection networks is still a challenge owing to high complexity. Need of reliability evaluation for MINs is quite evident as these measures provide user‐oriented performance. Terminal pair reliability (TPR) is the most commonly used reliability performance index of MINs. This paper provides a global view of different reliability measures and approaches for evaluation of these measures. Based on the critical literature review, shortcomings are identified and analyzed. Then the multi‐variable inversion algorithm is applied to evaluate the reliability of one of the most common MINs, namely, Omega network, in a compact form. Terminal, broadcast, and network reliability for the Omega, Omega with an additional stage (Omega+), and Omega with two additional stages (Omega+2) systems are analyzed and compared. Then we extend our work to trace the minimal path sets of various MINs, and terminal pair reliabilities are evaluated and compared. Copyright © 2015 John Wiley & Sons, Ltd.
Quantum chemical approaches for controlling and evaluating intramolecular magnetic interactions in organic diradicals
Authors: Cho Daeheum , Ko Kyoung Chul , Lee Jin Yong
Published: December 2015

In this review, rational design strategies for pure organic high‐spin molecules with strong intramolecular magnetic interactions are presented, mostly focusing on the design of ferromagnetically coupled organic diradicals. After brief introduction of the calculation procedure for intramolecular magnetic coupling constant J using density functional theory (DFT), classification and standardization of magnetic character of well‐known stable radicals and coupler units are discussed. Following the development of general strategy for the design of organic high‐spin diradical by means of the classification and standardization scheme, applicability of the strategy for making pendent‐type organic polyradical using zigzag graphene nanoribbons backbone is demonstrated. In a computational point of view, a scaling procedure and an optimization of Hartree–Fock exact exchange ratio of a hybrid DFT functional for better prediction of the J of diradicals are discussed. © 2015 Wiley Periodicals, Inc.
Dissociation of protonated N‐(3‐phenyl‐2H‐chromen‐2‐ylidene)‐ benzenesulfonamide in the gas phase: cyclization via sulfonyl cation transfer
Authors: Wang Shanshan , Dong Cheng , Yu Lian , Guo Cheng , Jiang Kezhi
Published: December 2015

Rationale

In the tandem mass spectrometry of protonated N‐(3‐phenyl‐2H‐chromen‐2‐ylidene)benzenesulfonamides, the precursor ions have been observed to undergo gas‐phase dissociation via two competing channels: (a) the predominant channel involves migration of the sulfonyl cation to the phenyl C atom and the subsequent loss of benzenesulfinic acid along with cyclization reaction, and (b) the minor one involves dissociation of the precursor ion to give an ion/neutral complex of [sulfonyl cation/imine], followed by decomposition to afford sulfonyl cation or the INC‐mediated electron transfer to give an imine radical cation.

Methods

The proposed reaction channels have been supported by theoretical calculations and D‐labeling experiments.

Results

The gas‐phase cyclization reaction originating from the N‐ to C‐sulfonyl cation transfer has been first reported to the best of our knowledge.

Conclusions

For the substituted sulfonamides, the presence of electron‐donating groups (R2‐) at the C‐ring effectively facilitates the reaction channel of cyclization reaction, whereas that of electron‐withdrawing groups inhibits this pathway. Copyright © 2015 John Wiley & Sons, Ltd.
Characterization of the designer drug deschloroketamine (2‐methylamino‐2‐phenylcyclohexanone) by gas chromatography/mass spectrometry, liquid chromatography/high‐resolution mass spectrometry, multistage mass spectrometry, and nuclear magnetic resonance
Authors: Frison Giampietro , Zamengo Luca , Zancanaro Flavio , Tisato Francesco , Traldi Pietro
Published: December 2015

Rationale

Clinical and forensic toxicology laboratories are challenged every day by the analytical aspects of the new psychoactive substances phenomenon. In this study we describe the analytical characterization of a new ketamine derivative, deschloroketamine (2‐methylamino‐2‐phenylcyclohexanone), contained in seized powders.

Methods

The analytical techniques employed include gas chromatography/mass spectrometry (GC/MS), liquid chromatography/electrospray ionization coupled with Orbitrap high‐resolution/MS (LC/ESI‐HRMS), multistage MS (ESI‐MSn), and NMR. The LC/ESI‐HRMS analyses consisted of accurate mass measurements of MH+ ions in full‐scan mode; comparison of experimental and calculated MH+ isotopic patterns; and examination of the isotopic fine structure (IFS) of the M + 1, M + 2, M + 3 isotopic peaks relative to the monoisotopic M + 0 peak. The collision‐induced product ions of the MH+ ions were studied by both HRMS and MSn. 1H and 13C NMR measurements were carried out to confirm the chemical structure of the analyte.

Results

The EI mass spectra obtained by GC/MS analysis showed the presence of molecular ions at m/z 203, and main fragment ions at m/z 175, 174, 160, 147, 146, and 132. The application of LC/ESI‐HRMS allowed us to obtain: the accurate mass of deschloroketamine MH+ ions with a mass accuracy of 1.47 ppm; fully superimposable experimental and calculated MH+ isotopic patterns, with a relative isotopic abundance value of 3.69 %; and the IFS of the M + 1, M + 2, M + 3 isotopic peaks completely in accordance with theoretical values. Examination of the product ions of MH+, as well as the study of both 1H and 13C NMR spectra, enabled the full characterization of the molecular structure of deschloroketamine.

Conclusions

The combination of the employed analytical techniques allowed the characterization of the seized psychoactive substance, in spite of the lack of a reference standard. Deschloroketamine is a ketamine analogue considered to be more potent and longer lasting than ketamine, and this paper is probably the first to report on its analytical characterization. Copyright © 2015 John Wiley & Sons, Ltd.
Effects of a proton‐conducting ionic liquid on secondary ion formation in time‐of‐flight secondary ion mass spectrometry
Authors: Fujiwara Yukio , Saito Naoaki
Published: December 2015

Rationale

A protic ionic liquid, diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]), has low vapor pressure and high protonic conductivity even at room temperature. Since [dema][TfO] has a mobile proton in its salt structure, its primary beam is expected to enhance the formation of protonated molecular ions. However, mass spectrometric characteristics of [dema][TfO] are not well known. In order to develop an ionic‐liquid primary beam source, it is necessary to investigate such characteristics.

Methods

The first time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS) experiment using an Ar+ primary ion beam was performed to analyze two samples: a neat [dema][TfO] sample and a mixed sample of arginine and [dema][TfO]. Beam characteristics of [dema][TfO] generated by vacuum electrospray were investigated using an apparatus for measuring transient responses of a beam current. The second TOF‐SIMS experiment using a [dema][TfO] primary beam was performed to analyze three samples: arginine, a mixture of arginine and [dema][TfO], and poly(ethylene glycol) (PEG300).

Results

The [dema][TfO] primary beam was useful in generating protonated arginine; however, it was not helpful in detecting PEG300. The results were explained by considering gas‐phase basicities and proton affinities of analytes and [dema][TfO] constituents. Projectile energy per nucleon of the [dema][TfO] beam was examined; it would be necessary to reduce m/z values of ionic‐liquid charged droplets. In addition, a screening method was proposed to select ionic liquids suitable for primary ion beams.

Conclusions

Since [dema][TfO] can act as a proton source, its primary beam can effectively generate protonated secondary ions of analytes. Consequently, proton‐conducting ionic liquids such as [dema][TfO] are expected to have great potentials as primary ion beams in TOF‐SIMS. Copyright © 2015 John Wiley & Sons, Ltd.
Application of liquid chromatography/electrospray ionization ion trap tandem mass spectrometry for the evaluation of global nucleic acids: methylation in garden cress under exposure to CuO nanoparticles
Authors: Alcazar Magana Armando , Wrobel Kazimierz , Corrales Escobosa Alma Rosa , Wrobel Katarzyna
Published: December 2015

Rationale

A full understanding of the biological impact of nanomaterials demands analytical procedures suitable for the detection/quantification of epigenetic changes that occur in the exposed organisms. Here, the effect of CuO nanoparticles (NPs) on global methylation of nucleic acids in Lepidium sativum was evaluated by liquid chromatography/ion trap mass spectrometry. Enhanced selectivity toward cytosine‐containing nucleosides was achieved by using their proton‐bound dimers formed in positive electrospray ionization (ESI(+)) as precursor ions for multiple reaction monitoring (MRM) quantification based on one or two ion transitions.

Methods

Plants were exposed to CuO NPs (0–1000 mg L–1); nucleic acid extracts were washed with bathocuproine disulfate; nucleosides were separated on a Luna C18 column coupled via ESI(+) to an AmaZon SL mass spectrometer (Bruker Daltonics). Cytidine, 2´‐deoxycytidine, 5‐methylcytidine, 5‐methyl‐2´‐deoxycytidine and 5‐hydroxymethyl‐2´‐deoxycytidine were quantified by MRM based on MS3 ([2M+H]+/[M+H]+/[M+H–132]+ or [M+H–116]+) and MS2 ([2M+H]+/[M+H]+).

Results

Bathocuproine disulfate, added as Cu(I) complexing agent, allowed for elimination of [2M+Cu]+ adducts from the mass spectra. Poorer instrumental detection limits were obtained for MS3 (20–120 fmol) as compared to MS2 (9.0–41 fmol); however, two ion transitions helped to eliminate matrix effects in plant extracts. The procedure was tested by analyzing salmon sperm DNA (Sigma) and applied for the evaluation of DNA and RNA methylation in plants; in the absence of NPs, 13.03% and 0.92% methylated cytosines were found in DNA and RNA, respectively; for NPs concentration >50 mg L–1, DNA hypomethylation was observed with respect to unexposed plants. RNA methylation did not present significant changes upon plant exposure; 5‐hydroxymethyl‐2´‐deoxycytidine was not detected in any sample.

Conclusions

The MRM quantification proposed here of cytosine‐containing nucleosides using their proton‐bound homo‐dimers as precursor ions proved its utility for the assessment of global methylation of DNA and RNA in plants under stress imposed by CuO NPs. Detection of copper adducts with cytosine‐containing ions, and their elimination by washing extracts with Cu(I) chelator, calls for further investigation. Copyright © 2015 John Wiley & Sons, Ltd.
Türme und Maste aus Stahl
Authors: Harling Andreas , Rost Markus , Ebbinghaus Martin , Lahne Jens
Published: December 2015

Türme und Maste sind nach Brücken das zweitwichtigste Ingenieurbauwerk der Gegenwart. Dieses Prädikat resultiert aus ihrer Präsenz und ihrer Vielfältigkeit hinsichtlich Alter, Nutzung, Konstruktion und Materialien. Fortschreitende technische Neuerungen, zum Beispiel die Offshore‐Windindustrie und die LTE‐Mobilfunktechnologie, erfordern auch in Zukunft die Weiternutzung vorhandener und die Errichtung neuer Bauwerke.

Stahlmaste und ‐türme sind vielseitig einsetzbar, leicht zu warten und kostengünstig zu ersetzen. Dank der Verzinkung sind konkurrenzfähige Standzeiten auch ohne zusätzlichen Korrosionsschutz erreichbar. Stahlanwendungen im Bereich der Maste und Türme sind wegen ihrer vergleichsweise leichten Bauweise gut zu modularisieren und typisieren. Auch die Eigenschaften heutiger Stahlsorten bezüglich Schweißbarkeit, Festigkeit und Zähigkeit haben zum Erfolg der Bauweise beigetragen. Die Inspektionszyklen dieser Ingenieurbauwerke sind sehr von ihrer Nutzung abhängig und in den entsprechenden Normen und Vorschriften festgelegt.

Towers and masts made of steel – Examples of their range of use and construction. Towers and masts constitute nowadays after bridges the second most important engineering structure. This claim is reasoned by presence and the diversity in terms of age, use, construction and materials. Technical innovations (e. g. offshore wind industry and LTE mobile technology) will continue to require the use of the existing and construction of new buildings.

Steel masts and towers are versatile, easy to maintain and their replacement is inexpensive. Thanks galvanizing competitive life expectations can also be reached without additional corrosion protection. Steel masts and towers can easily modularized and standardized due to light design. Moreover the modern steel grades with respect to their weldability, strength and ductility have contributed to the success of this type of structure. The needed inspection cycles given in the pertinent standards and regulations depend highly on the kind‐of‐use oft he considered structures.
Neue innovative Stahlprofilformen für Gittermasttürme
Authors: Tibolt Mike
Published: December 2015

Heutzutage finden Gittermasttürme eine weltweite Anwendung in Sende‐ und Freileitungsmasten sowie Windkraftanlagen. Windturbinen mit Stahlgittermasttürmen schienen von Rohrtürmen schon fast vollständig verdrängt und erleben zurzeit eine Renaissance. Die Ursache liegt in der kostengünstigen Lösung zum Erreichen größter Höhen, welche die Nutzung größerer Windgeschwindigkeiten ermöglichen. Somit können Wirkungsgrad und Turbinenleistung der Anlage gesteigert und die Rotorfläche verringert werden. Des Weiteren können die Fundamente von Gittermasttürmen im Vergleich zu Rohrtürmen konstruktiv wirtschaftlicher ausgeführt werden. Der Einsatz von verschraubten Winkelprofilen erlaubt einen einfachen Transport zur Baustelle und eine schnellen Aufbau des Gittermastturmes auf unwegsamem Gelände. Zudem kann der langzeitige Korrosionsschutz der Winkelprofile durch Verzinkung nahezu aufwandslos sichergestellt werden. Neu entwickelte größere Winkelprofile aus hochfestem Stahl erlauben eine noch wirtschaftlichere und nachhaltige Ausführung von Gittermasttürmen und machen Gittermasttürme langfristig über den Einsatz in Windkraftanlagen hinaus zu einer konkurrenzfähigen Lösung. In diesem Beitrag werden die von ArcelorMittal neu entwickelten Winkelprofile L300 aus hochfestem Stahl vorgestellt. Außerdem werden für die Winkelprofile neue Knickspannungskurven entsprechend EC 3 ermittelt, welche eine wirtschaftlichere Bemessung gegenüber den bisherigen in EC 3 vorgeschlagenen Kurven erlauben. Anschließend wird anhand einer Fallstudie das Potential der neuen Winkelprofile in Gittermasttürme aufgezeigt.

New and innovative steel profiles for lattice towers – Results from research and application. Nowadays, lattice towers are applied worldwide in telecommunication, transmission and wind turbine towers. Wind power stations with lattice towers have nearly been totally replaced by tube towers, but currently undergo a renaissance. The reason is the cost efficient solution for the achievement of big heights, which allow the exploitation of higher wind speeds. In this way, the degree of efficiency and the turbine output are improved with a smaller disk area. In addition, the fundaments of lattice towers are more economic in their execution than those of tube towers. The application of bolted angle profiles simplifies the transport and the erection of lattice towers in rough terrain. Moreover, the hot dip galvanization process of the angles assures a long‐lasting corrosion protection without extra effort. Newly developed heavy angle profiles using high strength steel allow an even more economic and sustainable design of lattice towers, which will become a competitive solution in future. In this paper, the newly developed angles L300 of ArcelorMittal using high strength steel are presented. Additionally, appropriate reduction curves according to EC 3 are determined for the angles. Finally the potential of the new angles in lattice towers is highlighted in a case study.