bluuebunny/crossref_metadata_2025_split 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

AbstractOne 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

AbstractBACKGROUNDPhytohormones 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.RESULTSIn 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.CONCLUSIONMetabolomics 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

PurposeTo 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 MethodsAn 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.ResultsThe 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.ConclusionThe 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

ABSTRACTEvapotranspiration 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.
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

AbstractThe 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

SummaryThe 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

AbstractBiphenols 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.
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

SummaryBackgroundThe 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.MethodsWe 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.ResultsWe 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.ConclusionsThe 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

AbstractThe 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.
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

RationaleIn 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.MethodsThe proposed reaction channels have been supported by theoretical calculations and D‐labeling experiments.ResultsThe gas‐phase cyclization reaction originating from the N‐ to C‐sulfonyl cation transfer has been first reported to the best of our knowledge.ConclusionsFor 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

RationaleClinical 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.MethodsThe 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.ResultsThe 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.ConclusionsThe 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.