bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of the power density for identifying reconnection regions
Authors: Hamrin M. , Andersson L. , Vaivads A. , Pitkänen T. , Gunell H. 
Published: September 2015

AbstractIn the vicinity of magnetic reconnection, magnetic energy is transferred into kinetic energy. A reconnection region hence corresponds to a load, and it should manifest itself as large and positive values of the power density, E·J ≫ 0, where E is the electric field and J the current density. In this article we analyze Cluster plasma sheet data from 2001–2004 to investigate the use of the power density for identifying possible magnetic reconnection events from large sets of observed data. From theoretical arguments we show that an event with
pW/m3 in the Earth's magnetotail observed by the Cluster instruments (X <− 10RE and
) is likely to be associated with reconnection. The power density can be used as a primary indicator of potential reconnection regions, but selected events must be reviewed separately to confirm any possible reconnection signatures by looking for other signatures such as Hall electric and magnetic fields and reconnection jets. The power density can be computed from multispacecraft data, and we argue that the power density can be used as a tool for identifying possible reconnection events from large sets of data, e.g., from the Cluster and the Magnetospheric Multiscale missions.
Characterization of rockfalls from seismic signal: Insights from laboratory experiments
Authors: Farin Maxime , Mangeney Anne , Toussaint Renaud , Rosny Julien de , Shapiro Nikolai , Dewez Thomas , Hibert Clément , Mathon Christian , Sedan Olivier , Berger Frédéric 
Published: September 2015

AbstractThe seismic signals generated by rockfalls can provide information on their dynamics and location. However, the lack of field observations makes it difficult to establish clear relationships between the characteristics of the signal and the source. In this study, scaling laws are derived from analytical impact models to relate the mass and the speed of an individual impactor to the radiated elastic energy and the frequency content of the emitted seismic signal. It appears that the radiated elastic energy and frequencies decrease when the impact is viscoelastic or elastoplastic compared to the case of an elastic impact. The scaling laws are validated with laboratory experiments of impacts of beads and gravels on smooth thin plates and rough thick blocks. Regardless of the involved materials, the masses and speeds of the impactors are retrieved from seismic measurements within a factor of 3. A quantitative energy budget of the impacts is established. On smooth thin plates, the lost energy is either radiated in elastic waves or dissipated in viscoelasticity when the impactor is large or small with respect to the plate thickness, respectively. In contrast, on rough thick blocks, the elastic energy radiation represents less than 5% of the lost energy. Most of the energy is lost in plastic deformation or rotation modes of the bead owing to surface roughness. Finally, we estimate the elastic energy radiated during field scale rockfalls experiments. This energy is shown to be proportional to the boulder mass, in agreement with the theoretical scaling laws.
JAML mediates monocyte and CD8 T cell migration across the brain endothelium
Authors: Alvarez Jorge Iván , Kébir Hania , Cheslow Lara , Chabarati Marc , Larochelle Catherine , Prat Alexandre 
Published: September 2015

AbstractLeukocyte transmigration into the central nervous system promotes multiple sclerosis pathogenesis, yet ambiguity remains regarding the mechanisms controlling the migration of distinct immune cell subsets. Using in vitro, ex vivo and postmortem human materials, we identified a significant upregulation of junctional adhesion molecule‐like expression at the blood–brain barrier, monocytes, and CD8 T cells of multiple sclerosis patients. We also detected junctional adhesion molecule‐like+ trans‐migratory cups when monocytes/CD8 T cells adhered to the blood–brain barrier, however, their migratory capacity was significantly compromised when junctional adhesion molecule‐like was blocked. These findings highlight a novel role for junctional adhesion molecule‐like in leukocyte transmigration and its potential as a promising therapeutic target.
Salt‐Free Reduction of Nonprecious Transition‐Metal Compounds: Generation of Amorphous Ni Nanoparticles for Catalytic C–C Bond Formation
Authors: Yurino Taiga , Ueda Yohei , Shimizu Yoshiki , Tanaka Shinji , Nishiyama Haruka , Tsurugi Hayato , Sato Kazuhiko , Mashima Kazushi 
Published: September 2015

AbstractA salt‐free procedure for the generation of a wide variety of metal(0) particles, including Fe, Co, Ni, and Cu, was achieved using 2,3,5,6‐tetramethyl‐1,4‐bis(trimethylsilyl)‐1,4‐diaza‐2,5‐cyclohexadiene (1), which reduced the corresponding metal precursors under mild conditions. Notably, Ni particles formed in situ from the treatment of Ni(acac)2 (acac=acetylacetonate) with 1 in toluene exhibited significant catalytic activity for reductive CC bond‐forming reactions of aryl halides in the presence of excess amounts of 1. By examination of high‐magnification transmission electron microscopy images and electron diffraction patterns, we concluded that amorphous Ni nanoparticles (Ni aNPs) were essential for the high catalytic activity.
Gold(I)‐Catalyzed Enantioselective Desymmetrization of 1,3‐Diols through Intramolecular Hydroalkoxylation of Allenes
Authors: Zi Weiwei , Toste F. Dean 
Published: September 2015

AbstractA gold(I)‐catalyzed enantioselective desymmetrization of 1,3‐diols was achieved by intramolecular hydroalkoxylation of allenes. The catalyst system 3‐F‐dppe(AuCl)2 /(R)‐C8‐TRIPAg proved to be specifically efficient to promote the desymmetrizing cyclization of 2‐aryl‐1,3‐diols, which have proven challenging substrates in previous reports. Multisubstituted tetrahydrofurans were prepared in good yield with good enantioselectivity and diastereoselectivity by this method.
A Mechanochemically Triggered “Click” Catalyst
Authors: Michael Philipp , Binder Wolfgang H. 
Published: September 2015

Abstract“Click” chemistry represents one of the most powerful approaches for linking molecules in chemistry and materials science. Triggering this reaction by mechanical force would enable site‐ and stress‐specific “click” reactions—a hitherto unreported observation. We introduce the design and realization of a homogeneous Cu catalyst able to activate through mechanical force when attached to suitable polymer chains, acting as a lever to transmit the force to the central catalytic system. Activation of the subsequent copper‐catalyzed “click” reaction (CuAAC) is achieved either by ultrasonication or mechanical pressing of a polymeric material, using a fluorogenic dye to detect the activation of the catalyst. Based on an N‐heterocyclic copper(I) carbene with attached polymeric chains of different flexibility, the force is transmitted to the central catalyst, thereby activating a CuAAC in solution and in the solid state.
Styrene‐butadiene‐styrene copolymer compatibilized interfacial modified multiwalled carbon nanotubes with mechanical and piezoresistive properties
Authors: Wang Lun , Wang Zhe , Wang Yue , Wang Xue , Wang Hengwei , Lu Guoming , Zhao Dongyu , Li Zewen 
Published: September 2015

ABSTRACTIn this study, styrene‐butadiene‐styrene tri‐block copolymer/multiwalled carbon nanotubes (SBS/MWNTs) were prepared by means of a solution blending method. To enhance the compatibility between SBS and MWNTs, the SBS grafted MWNTs (SBS‐g‐MWNTs) were used to replace MWNTs. The MWNTs were chemically hydroxylated by the dissolved KOH solution with ethanol as solvent and then reacted with 3‐Aminopropyltriethoxysilane (APTES) to functionalize them with amino groups (MWNT‐NH2). The SBS‐g‐MWNTs were finally obtained by the reaction of MWNT‐NH2 and maleic anhydride grafted SBS (MAH‐g‐SBS). The SBS‐g‐MWNTs were characterized by X‐ray photoelectron spectroscopy (XPS), Fourier transform‐infrared spectroscopy (FT‐IR), transmission electron microscopy (TEM), scanning electron microscope (SEM), and thermogravimetric analysis (TGA). The results showed that the SBS molecules were homogeneously bonded onto the surface of the MWNTs, leading to an improvement of the mechanical and electrical properties of SBS/SBS‐g‐MWNTs composites due to the excellent interfacial adhesion and dispersion of SBS‐g‐MWNTs in SBS. A series of continuous tests were carried out to explore the electrical‐mechanical properties of the SBS/SBS‐g‐MWNTs composites. We found out that, near the percolation threshold, the well‐dispersed SBS/SBS‐g‐MWNTs composites showed good piezoresistive characteristics and small mechanical destructions for the development of little deformation under vertical pressure. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42945.
Robust Input Covariance Constraint Control for Uncertain Polytopic Systems
Authors: Al‐Jiboory Ali Khudhair , Zhu Guoming 
Published: September 2015

AbstractIn this paper, the robust input covariance constraint (ICC) control problem with polytopic uncertainty is solved using convex optimization with linear matrix inequality (LMI) approach. The ICC control problem is an optimal control problem that optimizes the output performance subjected to multiple constraints on the input covariance matrices. This control problem has significant practical implications when hard constraints need to be satisfied on control actuators. The contribution of this paper is the characterization of the control synthesis LMIs used to solve the robust ICC control problem for polytopic uncertain systems. Both continuous‐ and discrete‐time systems are considered. Parameter‐dependent and independent Lyapunov functions have been used for robust ICC controller synthesis. Numerical design examples are presented to illustrate the effectiveness of the proposed approach.
Palladium(II) Acetate Catalyzed Reductive Heck Reaction of Enones; A Practical Approach
Authors: Mannathan Subramaniyan , Raoufmoghaddam Saeed , Reek Joost N. H. , de Vries Johannes G. , Minnaard Adriaan J. 
Published: September 2015

AbstractA surprisingly practical Pd(OAc)2 or Pd(TFA)2‐catalyzed reductive Heck reaction between aryl iodides and α,β‐unsaturated ketones is described using N,N‐diisopropylethylamine (DIPEA, Hünigs base) as the reductant. In general, 1 mol % of Pd(OAc)2 is sufficient to afford good yields using electron‐rich or halogen‐substituted aryl iodides. Electron‐deficient aryl iodides preferentially give homocoupling. Enones containing aryl or bulky substituents on the β‐carbon react smoothly, producing mainly reductive Heck product, whereas enones with alkyl substituents on the β‐carbon afford a mixture of reductive Heck and Heck product. Deuterium labeling experiments show that the reaction is a bona fide reductive Heck reaction and exclude a Heck reaction‐conjugate reduction cascade.
Has Afirma gene expression classifier testing refined the indeterminate thyroid category in cytology?
Authors: Yang Sung‐Eun , Sullivan Peggy S. , Zhang Jianhua , Govind Rekha , Levin Mary R. , Rao Jian‐Yu , Moatamed Neda A. 
Published: September 2015

BACKGROUNDThyroid fine‐needle aspiration (FNA) plays a pivotal role in the evaluation of thyroid nodules. Up to 30% of cases are diagnosed as indeterminate by FNA, including atypia of undetermined significance, follicular lesion of undetermined significance, suspicious for a follicular neoplasm, and follicular neoplasm, with approximately two‐thirds having a benign outcome. The gene expression classifier (GEC) test is a molecular test for cases with indeterminate cytology. The purpose of the current study was to examine the refining role of the GEC test within a single institution.METHODSRetrospective analysis of all thyroid FNAs during a 20‐month period after implementation of GEC was performed. Cases of indeterminate cytology with concomitant GEC testing were selected and divided further in 4 subgroups. Correlation with surgical follow‐up, when available, was performed. The results were compared with previously published data from the study institution before the implementation of GEC testing.RESULTSAmong the 217 cases, there were 189 with indeterminate cytology, 42% of which were benign and 50% of which were suspicious by GEC. The excisional rate of atypia of undetermined significance‐follicular lesion of undetermined significance in the pre‐GEC category was 63%, which decreased to 35% in the post‐GEC category, whereas the malignancy rate in the excised thyroids increased from 35% in the pre‐GEC category to 47% in the post‐GEC category. Similar findings also were obtained for suspicious for a follicular neoplasm‐follicular neoplasm lesions.CONCLUSIONSThe strength of the GEC test appears to lie in its ability to reclassify 42% of indeterminate cytology cases as benign, thereby decreasing the number of unnecessary surgical procedures. Cancer (Cancer Cytopathol) 2016;124:100–109. © 2015 American Cancer Society.
Yolk hormones influence in ovo chemosensory learning, growth, and feeding behavior in domestic chicks
Authors: Bertin Aline , Meurisse Maryse , Arnould Cécile , Leterrier Christine , Constantin Paul , Cornilleau Fabien , Vaudin Pascal , Burlot Thierry , Delaveau Joel , Rat Christophe , Calandreau Ludovic 
Published: September 2015

ABSTRACTIn this study, we assessed whether prenatal exposure to elevated yolk steroid hormones can influence in ovo chemosensory learning and the behavior of domestic chicks. We simulated a maternal environmental challenge by experimentally enhancing yolk progesterone, testosterone, and estradiol concentrations in hen eggs prior to incubation. The embryos from these hormones‐treated eggs (HO) as well as sham embryos (O) that had received the vehicle‐only were exposed to the odor of fish oil (menhaden) between embryonic Days 11 and 20. An additional group of control embryos (C) was not exposed to the odor. All chicks were tested following hatching for their feeding preferences between foods that were or were not odorized with the menhaden odor. In the 3‐min choice tests, the behavior of O chicks differed significantly according to the type of food whereas C and HO chicks showed no preference between odorized and non‐odorized food. Our result suggests weaker response in HO chicks. In addition, HO chicks showed impaired growth and reduced intake of an unfamiliar food on the 24‐h time scale compared to controls. Our data suggest that embryonic exposure to increased yolk hormone levels can alter growth, chemosensory learning, and the development of feeding behaviors. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 58: 185–197, 2016.
The developmental inter‐relationships between activity, novelty preferences, and delay discounting in male and female rats
Authors: Lukkes Jodi L. , Thompson Britta S. , Freund Nadja , Andersen Susan L. 
Published: September 2015

ABSTRACTIncreased locomotion, novelty‐seeking, and impulsivity are risk factors associated with substance use. In this study, the inter‐relationships between activity, novelty preferences, and delay discounting, a measure of impulsivity, were examined across three stages: juvenile/early adolescence (postnatal Day [P] 15, 19, and 42 for activity, novelty, and impulsivity, respectively), adolescent/late adolescent (P28, 32, 73), and adult (P90, 94, 137) in male and female rats. Our estimates of impulsive choice, where animals were trained to criterion, revealed an age × sex interaction where early adolescent females had the lowest levels of impulsivity. The relationships of activity and novelty to impulsivity significantly changed across age within each sex. Early adolescent males with high activity, but low novelty preferences, were more impulsive; however, low activity and high novelty preferences were related to high impulsivity in adult males. Female activity gradually increased across age, but did not show a strong relationship with impulsivity. Novelty preferences are moderately related to impulsivity into adulthood in females. These data show that males and females have different developmental trajectories for these behaviors. Males show greater sensation‐seeking (e.g., activity) and risky behavior (e.g., novelty preferences) earlier in life, whereas these behaviors emerge during adolescence in females. © 2015 Wiley Periodicals, Inc. Dev Psychobiol 58: 231–242, 2016.
A novel marine mesocosm facility to study global warming, water quality, and ocean acidification
Authors: Duarte Gustavo , Calderon Emiliano N. , Pereira Cristiano M. , Marangoni Laura F. B. , Santos Henrique F. , Peixoto Raquel S. , Bianchini Adalto , Castro Clovis B. 
Published: September 2015

AbstractWe describe a completely randomizable flow‐through outdoor mesocosm for climate change and ecotoxicology studies that was built with inexpensive materials. The 16 raceway tanks allow up to 6× water renewal per hour, avoiding changes in natural abiotic seawater conditions. We use an open‐source hardware board (Arduino) that was adapted to control heaters and an innovative CO2 injection system. This system reduced seawater pH up to −0.9 units and increased temperature up to +6°C in three treatments and a control. Treatments can be continuously compared with the control and vary according to diel fluctuations, thus following the diel range observed in the sea. The mesocosm facility also includes an integrated secondary system of 48 aquaria for ecotoxicology studies. We validated the reproducibility and relevance of our experimental system by analyzing the variation of the total DNA of the microbial community extracted from corals in three elevated temperature scenarios during a 40‐day experiment. We also present data from temperature, acidification, and copper contamination trials, which allowed continuous, reliable, and consistent treatment manipulations.
FeII Carbonyl Complexes Featuring Small to Bulky PNP Pincer Ligands – Facile Substitution of κ2P,N‐Bound PNP Ligands by Carbon Monoxide
Authors: Glatz Mathias , Holzhacker Christian , Bichler Bernhard , Mastalir Matthias , Stöger Berthold , Mereiter Kurt , Weil Matthias , Veiros Luis F. , Mösch‐Zanetti Nadia C. , Kirchner Karl 
Published: September 2015

AbstractComplexes trans‐ and cis‐[Fe(κ3P,N,P‐PNP)(CO)Cl2] complexes bearing sterically demanding to small PNP ligands based on the 2,6‐diaminopyridine scaffold are synthesized. The aromatic pyridine ring and the phosphine PR2 moieties are connected through NH, N‐alkyl, or N‐aryl linkers. For bulky PNP ligands, with the exception of the ligands with PtBu2 units, these complexes are obtained upon the treatment of [Fe(κ3P,N,P‐PNP)Cl2] with CO. With small PNP ligands, such complexes are not accessible directly owing to the formation of [Fe(κ3P,N,P‐PNP)(κ2P,N‐PNP)Cl]Cl. These complexes liberate the κ2‐P,N‐bound PNP ligand in the presence of CO to yield [Fe(κ3P,N,P‐PNP)(CO)Cl2] in yields of less than 50 %. High yields are achieved by reacting FeCl2 with PNP ligands under a CO atmosphere. For structural and reactivity comparisons, [Fe(κ3P,N,P‐PNP‐Ph)(κ2P,N‐PN‐Ph)Cl]+ was prepared, and this complex does not react with CO. In contrast to the reactions in solution, in the solid state, complexes [Fe(κ3P,N,P‐PNP)Cl2] with NH linkers are also converted quantitatively into trans‐ or cis‐[Fe(κ3P,N,P‐PNP)(CO)(Cl)2] upon treatment with CO, as indicated by a color change and by IR spectroscopy monitoring. Those with N‐alkyl and N‐aryl linkers did not react with CO. To rationalize why most [Fe(κ3P,N,P‐PNP)Cl2] complexes react readily with CO but those with tBu substituents do not, the additions of CO to [Fe(κ3P,N,P‐PNP‐iPr)Cl2] and [Fe(κ3P,N,P‐PNP‐tBu)Cl2] were investigated by DFT calculations.
Synthesis and Assessment of CO‐Release Capacity of Manganese Carbonyl Complexes Derived from Rigid α‐Diimine ­Ligands of Varied Complexity
Authors: Jimenez Jorge , Chakraborty Indranil , Mascharak Pradip K. 
Published: September 2015

AbstractFour manganese carbonyl complexes of the type [MnBr(CO)3(NN)] (NN = α‐diimine ligands): namely [MnBr(CO)3(bpy)] (1), [MnBr(CO)3(phen)] (2), [MnBr(CO)3(dafo)] (3), and [MnBr(CO)3(pyzphen)] (4) (where bpy = bipyridine, phen = 1,10‐phenanthroline, dafo = 4,5‐diazafluoren‐9‐one, and pyzphen = pyrazino[2,3‐f][1,10]‐phenanthroline) have been synthesized and structurally characterized. These four complexes, each containing the fac‐[Mn(CO)3] motif, release CO upon illumination with low‐power visible and UV light. The CO release rates and the absorption maxima of the complexes are, however, very similar, despite the systematic increase in structural complexity in the rigid α‐diimine ligand frameworks. This contrasts strongly with manganese carbonyl complexes derived from α‐diimine ligands in which at least one of the imine functions is not part of a rigid ring system. The results of this study should provide help in the future design of ligand frameworks suitable for the syntheses of photoCORMs to deliver CO to biological targets under the control of light.
Total Synthesis and Structural Reassignment of the γ‐Lactone Polyketide from Diaporthe sp. SXZ‐19
Authors: Yadav Jhillu S. , Dutta Palash , Ganganna Bogonda , Srinivas Eedubilli 
Published: September 2015

AbstractThe first stereoselective total synthesis of the proposed structure of the γ‐lactone from Diaporthe sp. SXZ‐19 was achieved by utilizing a convergent pathway. The four stereogenic centers were formed by employing Brown's asymmetric alkoxyallylboration reaction, and a cross‐metathesis reaction was used to construct the trans double bond of the γ‐lactone side chain. This synthesis led to a revision of proposed structural assignment of the natural product.
Synthesis of Alkynyl‐Glycinols by Lewis Acid Catalyzed Propargylic Substitution of Bis‐Imidates
Authors: Sirotkina Jekaterina , Grigorjeva Liene , Jirgensons Aigars 
Published: September 2015

AbstractRacemic and enantioenriched alkynyl‐glycinols can be synthesized by Lewis acid catalyzed cyclization reaction of bis‐trichloracetimidates derived from alkynyl‐glycols. The cyclization proceeds selectively to give 4‐alkynyl‐oxazolines as the propargylic substitution products. Enantioenriched bis‐imidates that contain an alkyl or trimethylsilyl substituent at the acetylene gave oxazolines with complete inversion of configuration. In turn, considerable racemization was observed in the cyclization of bis‐imidates that contain a phenyl substituent. The racemization for these substrates can be suppressed by introduction of the electronegative substituent at the phenyl ring. Oxazolines prepared by bis‐imidate cyclization reaction can be readily transformed to protected alkynyl‐glycol derivatives.
Reactions of Thioacetamide Derivatives with Sulfonyl Azides: An Approach to Active‐Methylene N‐Sulfonylacetamidines
Authors: Dianova Lidia , Berseneva Vera , Beryozkina Tetyana , Efimov Ilya , Kosterina Maria , Eltsov Oleg , Dehaen Wim , Bakulev Vasiliy 
Published: September 2015

AbstractReactions of functionalized [CN, CO2Et, C(O)NHR, C(S)NR1R2] derivatives of thiomalonic acid and 2‐arylthioacetamides with sulfonyl azides were shown to give active‐methylene N‐sulfonylamidines in 62–98 % yields. Various procedures for the reactions, including the use of pyridine, boiling ethanol, and water, or running the reactions in the absence of a base and solvent at 80 °C, were carried out and compared. The solvent‐free variant was the best in terms of yield, and also because it does not require the use of an excess of the toxic and hazardous azides. The reaction was shown to tolerate electron‐withdrawing substituents such as carbonyl, cyano, and aryl groups at the C‐2 position. The presence of alkyl and phenyl groups on the nitrogen atom of the thioacetamide fragment, and the presence of substituents on the sulfonyl group were also tolerated. Thus, an efficient solvent‐free, catalyst‐free, and base‐free synthetic approach for the synthesis of N‐sulfonylmalonacetamidines and 2‐arylacetamidines was found.