bluuebunny/crossref_metadata_2025_split huggingface dataset:
[Cs6Cl][Fe24Se26]: A Host–Guest Compound with Unique Fe–Se Topology
Authors: Valldor Martin , Böhme Bodo , Prots Yurii , Borrmann Horst , Adler Peter , Schnelle Walter , Watier Yves , Kuo Chang Yang , Pi Tun‐Wen , Hu Zhiwei , Felser Claudia , Tjeng Liu Hao 
Published: February 2016

AbstractThe novel host–guest compound [Cs6Cl][Fe24Se26] (I4/mmm; a=11.0991(9), c=22.143(2) Å) was obtained by reacting Cs2Se, CsCl, Fe, and Se in closed ampoules. This is the first member of a family of compounds with unique Fe–Se topology, which consists of edge‐sharing, extended fused cubane [Fe8Se6Se8/3] blocks that host a guest complex ion, [Cs6Cl]5+. Thus Fe is tetrahedrally coordinated and divalent with strong exchange couplings, which results in an ordered antiferromagnetic state below TN=221 K. At low temperatures, a distribution of hyperfine fields in the Mössbauer spectra suggests a structural distortion or a complex spin structure. With its strong Fe–Se covalency, the compound is close to electronic itinerancy and is, therefore, prone to exhibit tunable properties.
Comparing Ullmann Coupling on Noble Metal Surfaces: On‐Surface Polymerization of 1,3,6,8‐Tetrabromopyrene on Cu(111) and Au(111)
Authors: Pham Tuan Anh , Song Fei , Nguyen Manh‐Thuong , Li Zheshen , Studener Florian , Stöhr Meike 
Published: February 2016

AbstractThe on‐surface polymerization of 1,3,6,8‐tetrabromopyrene (Br4Py) on Cu(111) and Au(111) surfaces under ultrahigh vacuum conditions was investigated by a combination of scanning tunneling microscopy (STM), X‐ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations. Deposition of Br4Py on Cu(111) held at 300 K resulted in a spontaneous debromination reaction, generating the formation of a branched coordination polymer network stabilized by C−Cu−C bonds. After annealing at 473 K, the C−Cu−C bonds were converted to covalent C−C bonds, leading to the formation of a covalently linked molecular network of short oligomers. In contrast, highly ordered self‐assembled two‐dimensional (2D) patterns stabilized by both Br−Br halogen and Br−H hydrogen bonds were observed upon deposition of Br4Py on Au(111) held at 300 K. Subsequent annealing of the sample at 473 K led to a dissociation of the C−Br bonds and the formation of disordered metal‐coordinated molecular networks. Further annealing at 573 K resulted in the formation of covalently linked disordered networks. Importantly, we found that the chosen substrate not only plays an important role as catalyst for the Ullmann reaction, but also influences the formation of different types of intermolecular bonds and thus, determines the final polymer network morphology. DFT calculations further support our experimental findings obtained by STM and XPS and add complementary information on the reaction pathway of Br4Py on the different substrates.
Determination of the Influence of Side‐Chain Conformation on Glycosylation Selectivity using Conformationally Restricted Donors
Authors: Dharuman Suresh , Crich David 
Published: February 2016

AbstractThe synthesis of a series of conformationally locked mannopyranosyl thioglycosides in which the C6−O6 bond adopts either the gauche,gauche, gauche,trans, or trans,gauche conformation is described, and their influence on glycosylation stereoselectivity investigated. Two 4,6‐O‐benzylidene‐protected mannosyl thioglycosides carrying axial or equatorial methyl groups at the 6‐position were also synthesized and the selectivity of their glycosylation reactions studied to enable a distinction to be made between steric and stereoelectronic effects. The presence of an axial methoxy group at C6 in the bicyclic donor results in a decreased preference for formation of the β‐mannoside, whereas an axial methyl group has little effect on selectivity. The result is rationalized in terms of through‐space stabilization of a transient intermediate oxocarbenium ion by the axial methoxy group resulting in a higher degree of SN1‐like character in the glycosylation reaction. Comparisons are made with literature examples and exceptions are discussed in terms of pervading steric effects layered on top of the basic stereoelectronic effect.
Continuous‐Flow N‐Heterocyclic Carbene Generation and Organocatalysis
Authors: Di Marco Lorenzo , Hans Morgan , Delaude Lionel , Monbaliu Jean‐Christophe M. 
Published: February 2016

AbstractTwo methods were assessed for the generation of common N‐heterocyclic carbenes (NHCs) from stable imidazol(in)ium precursors using convenient and straightforward continuous‐flow setups with either a heterogeneous inorganic base (Cs2CO3 or K3PO4) or a homogeneous organic base (KN(SiMe3)2). In‐line quenching with carbon disulfide revealed that the homogeneous strategy was most efficient for the preparation of a small library of NHCs. The generation of free nucleophilic carbenes was next telescoped with two benchmark NHC‐catalyzed reactions; namely, the transesterification of vinyl acetate with benzyl alcohol and the amidation of N‐Boc‐glycine methyl ester with ethanolamine. Both organocatalytic transformations proceeded with total conversion and excellent yields were achieved after extraction, showcasing the first examples of continuous‐flow organocatalysis with NHCs.
Triptycene‐Roofed Quinoxaline Cavitands for the Supramolecular Detection of BTEX in Air
Authors: Bertani Federico , Riboni Nicolò , Bianchi Federica , Brancatelli Giovanna , Sterner Elizabeth S. , Pinalli Roberta , Geremia Silvano , Swager Timothy M. , Dalcanale Enrico 
Published: February 2016

AbstractInvited for the cover of this issue are the groups of Enrico Dalcanale at the University of Parma and Timothy M. Swager at Massachusetts Institute of Technology alongside collaborators at the University of Trieste. The image depicts the capture of aromatic hydrocarbons molecules by the ditrypticene quinoxaline cavitand that was employed as fiber coating for solid‐phase microextraction monitoring in air. Read the full text of the article at 10.1002/chem.201504229.
The pursuit of HR outsourcing in an emerging economy: The effects of HRM strategy on HR labour costs
Authors: Abdul‐Halim Hasliza , Che‐Ha Norbani , Geare Alan , Ramayah T. 
Published: February 2016

AbstractThe study examines the relationships among six types of HRM strategies with three categories of outsourcing HR activities to reduce HR labour costs. The data were gathered from a survey questionnaire of 232 manufacturing organizations of which 113 organizations engaged with HR outsourcing. We found that no organization outsourced transformational HR functions and that organizations that espouse cost efficiency, commitment, and conventional HRM strategies tend to outsource traditional HR functions, whereas quality conscious and commitment HRM strategies tend to outsource transactional HR functions. Transactional and traditional HR functions show a significant relationship with a reduction in HR labour costs. Copyright © 2016 ASAC. Published by John Wiley & Sons, Ltd.
p16‐positive lymph node metastases from cutaneous head and neck squamous cell carcinoma: No association with high‐risk human papillomavirus or prognosis and implications for the workup of the unknown primary
Authors: McDowell Lachlan J. , Young Richard J. , Johnston Meredith L. , Tan Tze‐Jian , Kleid Stephen , Liu Chen S. , Bressel Mathias , Estall Vanessa , Rischin Danny , Solomon Benjamin , Corry June 
Published: February 2016

BACKGROUNDThe incidence of p16 overexpression and the role of human papillomavirus (HPV) in cutaneous head and neck squamous cell carcinoma (cHNSCC) are unclear.METHODSOne hundred forty‐three patients with cHNSCC lymph node metastases involving the parotid gland were evaluated for p16 expression by immunohistochemistry. The detection of 18 high‐risk HPV subtypes was performed with HPV RNA in situ hybridization for a subset of 59 patients. The results were correlated with clinicopathological features and outcomes.RESULTSThe median follow‐up time was 5.3 years. No differences were observed in clinicopathological factors with respect to the p16 status. p16 was positive, weak, and negative in 45 (31%), 21 (15%), and 77 cases (54%), respectively. No high‐risk HPV subtypes were identified, regardless of the p16 status. The p16 status was not prognostic for overall (hazard ratio, 1.08; 95% confidence interval [CI], 0.85‐1.36; P = .528), cancer‐specific (hazard ratio, 1.12; 95% CI, 0.77‐1.64; P = .542), or progression‐free survival (hazard ratio, 1.03; 95% CI, 0.83‐1.29; P = .783). Distant metastasis‐free survival, freedom from locoregional failure, and freedom from local failure were also not significantly associated with the p16 status.CONCLUSIONSp16 positivity is common but not prognostic in cHNSCC lymph node metastases. High‐risk HPV subtypes are not associated with p16 positivity and do not appear to play a role in this disease. HPV testing, in addition to the p16 status in the unknown primary setting, may provide additional information for determining a putative primary site. Cancer 2016;122:1201–8. © 2016 American Cancer Society.
Strong Cosmic Censorship for Surface‐Symmetric Cosmological Spacetimes with Collisionless Matter
Authors: Dafermos Mihalis , Rendall Alan D. 
Published: February 2016

AbstractThis paper addresses strong cosmic censorship for spacetimes with self‐gravitating collisionless matter, evolving from surface‐symmetric compact initial data. The global dynamics exhibit qualitatively different features according to the sign of the curvature k of the symmetric surfaces and the cosmological constant Λ. With a suitable formulation, the question of strong cosmic censorship is settled in the affirmative if Λ=0 or k≤0, Λ > 0. In the case Λ > 0, k=1, we give a detailed geometric characterization of possible “boundary” components of spacetime; the remaining obstruction to showing strong cosmic censorship in this case has to do with the possible formation of extremal Schwarzschild–de Sitter‐type black holes. In the special case that the initial symmetric surfaces are all expanding, strong cosmic censorship is shown in the past for all k,Λ. Finally, our results also lead to a geometric characterization of the future boundary of black hole interiors for the collapse of asymptotically flat data: in particular, in the case of small perturbations of Schwarzschild data, it is shown that these solutions do not exhibit Cauchy horizons emanating from i +  with strictly positive limiting area radius.© 2016 Wiley Periodicals, Inc.
Long‐Lived Excited‐State Dynamics of i‐Motif Structures Probed by Time‐Resolved Infrared Spectroscopy
Authors: Keane Páraic M. , Baptista Frederico R. , Gurung Sarah P. , Devereux Stephen J. , Sazanovich Igor V. , Towrie Michael , Brazier John A. , Cardin Christine J. , Kelly John M. , Quinn Susan J. 
Published: February 2016

AbstractUV‐generated excited states of cytosine (C) nucleobases are precursors to mutagenic photoproduct formation. The i‐motif formed from C‐rich sequences is known to exhibit high yields of long‐lived excited states following UV absorption. Here the excited states of several i‐motif structures have been characterized following 267 nm laser excitation using time‐resolved infrared spectroscopy (TRIR). All structures possess a long‐lived excited state of ∼300 ps and notably in some cases decays greater than 1 ns are observed. These unusually long‐lived lifetimes are attributed to the interdigitated DNA structure which prevents direct base stacking overlap.
Size‐Dependent Electrocatalytic Activity of Free Gold Nanoparticles for the Glucose Oxidation Reaction
Authors: Hebié Seydou , Napporn Teko W. , Morais Cláudia , Kokoh K. Boniface 
Published: February 2016

AbstractUnderstanding the fundamental relationship between the size and the structure of electrode materials is essential to design catalysts and enhance their activity. Therefore, spherical gold nanoparticles (GNSs) with a mean diameter from 4 to 15 nm were synthesized. UV/Vis spectroscopy, transmission electron microscopy, and under‐potential deposition of lead (UPDPb) were used to determine the morphology, size, and surface crystallographic structure of the GNSs. The UPDPb revealed that their crystallographic facets are affected by their size and the growth process. The catalytic properties of these GNSs toward glucose electrooxidation were studied by cyclic voltammetry, taking into account the scan rate and temperature effects. The results clearly show the size‐dependent electrocatalytic activity for glucose oxidation reactions that are controlled by diffusion. Small GNSs with an average size of 4.2 nm exhibited high catalytic activity. This drastic increase in activity results from the high specific area and reactivity of the surface electrons induced by their small size. The reaction mechanism was investigated by in situ Fourier transform infrared reflectance spectroscopy. Gluconolactone and gluconate were identified as the intermediate and the final reaction product, respectively, of the glucose electrooxidation.
Influences of Pulsed Electric Fields on the Gene Expression of Pathogenic Bacteria
Authors: MANABE YUYA , MAETANI MIKI , NAGANO AKIHIKO , TERANISHI KENJI , SHIMOMURA NAOYUKI , TAKAHASHI AKIRA 
Published: February 2016

SUMMARYIn the biological and medical fields, sterilization using pulsed electric fields or discharges and electroporation have been studied actively in recent years. It is clear that a pulsed electric field has some sort of effect on an organism. At present, however, it is not sufficiently clear what effect occurs and how the mechanism of a pulsed electric field acts on the organism. The effects of pulsed electric fields on ribonucleic acid (RNA) expression in biological cells were studied with the objective of elucidating the bioelectric mechanism. A pulsed electric field was applied to Vibrio parahaemolyticus, a pathogenic bacteria, and the expression of RNAs, specifically thermostable direct hemolysin (TDH), VP1680, and VP1699, which represent pathogenic agents, were analyzed using the polymerase chain reaction (PCR) method. The level of expression of VP1680 increased when a pulsed electric field was applied, and the effect was at a peak when the electric field strength was 14 kV/cm. The electric field strength barely affected the expression of TDH and VP1699. It was found that the effects of the electric field were different among the RNAs. The expression level varied with time when expression was analyzed. These results suggest the possibility of selective control of gene expression by using pulsed electric fields and possible new applications such as the development of functional foods.
Experimental and Computational Study of Unique Tetranuclear µ3‐Chloride and µ‐Phenoxo/Chloro‐Bridged Defective Dicubane Cobalt(II) Clusters
Authors: Hänninen Mikko. M. , Välivaara Juha , Cano Joan , Sillanpää Reijo , Colacio Enrique 
Published: February 2016

AbstractTwo tetranuclear CoII clusters [Co4(L)2(µ3‐Cl)2Cl2] have been prepared by using multidentate diaminobisphenolate ligands. The solid‐state structures of the complexes were determined by single‐crystal X‐ray diffraction. The cores of the cluster compounds can be defined as a two‐vertex‐deficient dicubane geometry (pseudo‐dicubane). In the central unit, the cobalt(II) cations are linked through phenoxide oxygen (outer bridges) and chloride anions (inner bridges), previously unprecedented in this type of cobalt cluster. The magnetic properties were studied by both experimental and computational methods. By using a combination of techniques, we were able to determine the nature and strength of the intramolecular magnetic exchange coupling mediated by the different bridging fragments between the crystallographically different cobalt(II) cations.
Synthesis of a Family of ([SnSe]1+δ)m­([{MoxNb1x}Se2]1+γ)1([SnSe]1+δ)m­({Nbx­Mo1–x}Se2)1 Superlattice ­Heterostructures (m = 0, 1, 2, 3, 4 ­and 0.8 ≤ x ≤ 1)
Authors: Westover Richard D. , Mitchson Gavin , Ditto Jeffrey J. , Johnson David C. 
Published: February 2016

AbstractA family of multiple‐component heterostructures, ([SnSe]1+δ)m([{MoxNb1–x}Se2]1+γ)1([SnSe]1+δ)m({NbxMo1–x}Se2)1 (m = 0, 1, 2, 3, 4 and 0.8 ≤ x ≤ 1), was self‐assembled from designed amorphous precursors, and their structure and physical properties were characterized. The compounds consist of MoSe2 and NbSe2 layers with metal centers in a trigonal‐prismatic environment interleaved with systematically increasing numbers of SnSe bilayers with a distorted rock salt structure. The extent of alloying of the miscible dichalcogenide constituents decreased from about 20 % for m = 0 to less than 1 % for m = 3 and 4. The decreased alloying with increased SnSe thickness suggests the diffusion lengths of Mo and Nb during self‐assembly are about a nanometer. Resistivity and Hall coefficient measurements show that the electrical transport properties are similar to those of ([SnSe]1+δ)m(NbSe2)1 (m = 1–8) compounds, suggesting that the NbSe2 layer dominates the conductivity and that charge transfer from SnSe reduces the carrier concentration in the NbSe2 layer.
Application of Deep Eutectic Solvents in Promiscuous Lipase‐Catalysed Aldol Reactions
Authors: González‐Martínez Daniel , Gotor Vicente , Gotor‐Fernández Vicente 
Published: February 2016

AbstractThe application of deep eutectic solvents has been demonstrated for the first time in promiscuous lipase‐catalysed aldol reactions. The model reaction between 4‐nitrobenzaldehyde and acetone was examined in depth, with excellent compatibility being found between porcine pancreas lipase and choline chloride/glycerol mixtures for the formation of the aldol product in high yields. The system was compatible with a series of aromatic aldehydes and ketones including acetone, cyclopentanone and cyclohexanone. In some cases, the corresponding α,β‐unsaturated carbonyl compounds were found as minor products. Control experiments demonstrate that the enzymatic preparation was also responsible for a collateral dehydration reaction once the aldol product is formed.
Model Studies towards Functionalized Bisbenzannulated [5,6]‐Spiro­ketals
Authors: Wilsdorf Michael , Lentz Dieter , Reissig Hans‐Ulrich 
Published: February 2016

AbstractFollowing up on our previous model studies on the synthesis of simple bisbenzannulated [5,6]‐spiroketals we here report the preparation of new examples of this entity with a variation in their substitution pattern. The regioselective introduction of functional groups in the C‐3 or C‐3′ positions (rubromycin numbering) may either take place prior to the spiroketalization by α‐functionalizations of the ketone moiety of the precursor or in a subsequent step by the nucleophilic substitution of the benzylic hydroxy group of the previously described C‐3‐hydroxylated spiroketal. By applying these methods we could synthesize new methyl‐substituted, hydroxylated, halogenated and amino‐substituted bisbenzannulated [5,6]‐spiroketals in good overall yields.
Diversity Oriented Synthesis of Allocolchicinoids with Fluoro and/or Oxygen Substituent(s) on the C‐Ring from a Single Common Intermediate
Authors: Takubo Keita , Furutsu Kazunori , Ide Takafumi , Nemoto Hiroyuki , Ueda Yuko , Tsujikawa Kazutake , Ikawa Takashi , Yoshimitsu Takehiko , Akai Shuji 
Published: February 2016

AbstractAllocolchicinoids, with a distinct polyoxygenated dibenzocycloheptane skeleton, attract much attention as potential candidate anticancer drugs. In this study, eight C‐ring fluorinated analogues of allocolchicinoids, seven C‐ring oxygen‐substituted analogues, and known compounds N‐acetylcolchinol and NSC 51046 were synthesized as racemates from a single common intermediate by using either the deoxyfluorination/migration domino reaction or acid‐promoted migration as the key step. Among the products obtained, some of the fluorinated derivatives strongly inhibited the growth of prostate DU145 and pancreas Panc 1 cancer cell lines with efficacy comparable to or better than those of N‐acetylcolchinol and NSC 51046. They were also less toxic against a non‐cancerous cell line than the known compounds were.
Certification of a New Naringenin Reference Material by Coulometric Titrimetry Combined HPLC‐MS
Authors: Yang Dezhi , Zhang Baoxi , Zhang Li , Lu Yang 
Published: February 2016

AbstractCertified reference material (CRM) is a kind of measuring tool with high accuracy and traceability. CRMs are the important guarantee of accurate and reliable results of analysis methods. They are the medium of international communication of experimental data. CRMs are widely used in various fields and play a pivotal role in analytical science. However, in the characterization of CRMs, available absolute analysis methods are very limited. In this situation, accurate and reliable relative analysis methods should be applied. In this work, coulometric titrimetry (CT) was applied to the characterization of flavone naringenin CRM according to its structure. For further illustration of the principle of CT, high‐performance liquid chromatography tandem mass spectrometry (HPLC‐MS) was utilized to analyze the titration products in detail. As the conclusion of this paper, the advantages and the influence factors of CT were given. Mass balance (MB) method was employed to verify the result of CT, and consistent result was obtained.
A Facile Chemical Synthesis of Cu2O Nanocubes Covered with Co3O4 Nanohexagons for the Sensitive Detection of Glucose
Authors: Velmurgan Sakthi , Devasenathipathy Rajkumar , Chen Shen‐Ming , Wang Sea‐Fue 
Published: February 2016

AbstractCopper (I) oxide nanocubes (Cu2O NCs) covered with cobalt oxide nanohexagons (Co3O4 NHs) were prepared through simple chemical method. Here, ascorbic acid is used as reducing and capping agent for the synthesis of nanocubes and nanohexagons. Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy‐dispersive X‐ray spectroscopy (EDX) and X‐ray diffraction spectroscopy (XRD) were employed to confirm the prepared nanocomposite. Cu2O NCs−Co3O4 NHs nanocomposite is drop cast on the glassy carbon electrode (GCE) for the fabrication of glucose sensor. The fabricated Cu2O NCs−Co3O4 NHs/GCE exhibited a better electrocatalytic activity towards the determination of glucose than that of individually fabricated Cu2O NCs and Co3O4 NHs modified GCE. Our finding exhibited a wide linear range from 1 μM to 5330 μM with LOD of 0.63 towards glucose. In addition, the sensor attained appreciable stability, repeatability and reproducibility. Practicality of the sensor was demonstrated in human serum samples. The main advantages of the fabricated sensor are simple, biocompatible, cost effective, fast response and highly stable electrode surface.
Capturing CO2 Emissions in the Iron Industries using a Magnetite–Iron Mixture
Authors: Kumar Sushant , Drozd Vadym , Durygin Andriy , Saxena Surendra K. 
Published: February 2016

AbstractWe examined a mixture of magnetite (Fe3O4) and iron (Fe) as a possible CO2 sorbent easily applicable for any ironmaking industries. The mixture reacts with CO2 to form siderite (FeCO3). Our experimental results illustrate a capture capacity of 7.98 mmol

for the reactant mixture at 200 °C and 10 bar CO2 pressure in 3 h. The results also show that the kinetics of the carbonation reaction vastly depend on the applied temperature and CO2 pressure. The magnetite was completely regenerated by heating siderite at 350 °C under air flow. The proposed set of reactions can be integrated at any ironmaking sites and can provide a potential solution for CO2 capture in the future.