bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Mechanistic Insight into Stepwise Metal‐Center Exchange in a Metal–Organic Framework Based on Asymmetric Zn4 Clusters
Authors: Meng Wei , Li Huijun , Xu Zhouqing , Du Shanshan , Li Yunxia , Zhu Yanyan , Han Yi , Hou Hongwei , Fan Yaoting , Tang Mingsheng 
Published: February 2014

AbstractHerein, a mechanism of stepwise metal‐center exchange for a specific metal–organic framework, namely, [Zn4(dcpp)2(DMF)3(H2O)2]n (H4dcpp=4,5‐bis(4′‐carboxylphenyl)phthalic acid), is disclosed for the first time. The coordination stabilities between the central metal atoms and the ligands as well as the coordination geometry are considered to be dominant factors in this stepwise exchange mechanism. A new magnetic analytical method and a theoretical model confirmed that the exchange mechanism is reasonable. When the metathesis reaction occurs between CuII ions and framework ZnII ions, the magnetic exchange interaction of each pair of CuII centers gradually strengthens with increasing amount of framework CuII ions. By analyzing the changes of coupling constants in the Cu‐exchanged products, it was deduced that Zn4 and Zn3 are initially replaced, and then Zn1 and Zn2 are replaced later. The theoretical calculation further verified that Zn4 is replaced first, Zn3 next, then Zn1 and Zn2 last, and the coordination stability dominates the Cu/Zn exchange process. For the Ni/Zn and Co/Zn exchange processes, besides the coordination stability, the preferred coordination geometry was also considered in the stepwise‐exchange behavior. As NiII and CoII ions especially favor octahedral coordination geometry in oxygen‐ligand fields, NiII ions and CoII ions could only selectively exchange with the octahedral ZnII ions, as was also confirmed by the experimental results. The stepwise metal‐exchange process occurs in a single crystal‐to‐single crystal fashion.
Unprecedented High‐Nuclear Transition‐Metal‐Cluster‐Substituted Heteropolyoxoniobates: Synthesis by {V8} Ring Insertion into the POM Matrix and Antitumor Activities
Authors: Shen Jian‐Qiang , Wu Qiong , Zhang Ying , Zhang Zhi‐Ming , Li Yang‐Guang , Lu Ying , Wang En‐Bo 
Published: February 2014

AbstractReactions of hexaniobate with vanadate in the presence of Ni2+, Zn2+, or Cu2+ have furnished three high‐nuclear vanadium cluster‐substituted heteropolyoxoniobates (HPNs): {Ni(en)3}5H{VVNb8VIV8O44}⋅9 H2O (1), (H2en)Na2[{Zn(en)2(Hen)}{Zn(en)2(H2O)}2{PNb8VIV8O44}]⋅11 H2O (2), and Na{Cu(en)2}3{[Cu(en)2]2[PNb8VIV8O44]}⋅11 H2O (3) (en=1,2‐diaminoethane). Their structures have been determined and characterized by single‐crystal X‐ray diffraction analysis, thermogravimetric analysis (TGA), and elemental analysis. Structural analysis has revealed that compounds 1–3 contain similar {V8}‐substituted [XVNb8VIV8O44]11− (X=P, V) clusters, obtained by inserting a {V8} ring into tetravacant HPN [XNb8O36]27−. To the best of our knowledge, compounds 1–3 represent the first high‐nuclear vanadium cluster‐substituted HPNs, and compound 1 is the largest vanadoniobate cluster yet obtained in HPN chemistry. Nickel and zinc cations have been introduced into HPNs for the first time, which might promise a more diverse set of structures in this family. Antitumor studies have indicated that compounds 1 and 2 exhibit high activity against human gastric cancer SGC‐7901 cells, SC‐1680 cells, and MG‐63 cells.
Comprehensive Evaluation of the Physicochemical Properties of LnIII Complexes of Aminoethyl‐DO3A as pH‐Responsive T1‐MRI Contrast Agents
Authors: Baranyai Zsolt , Rolla Gabriele A. , Negri Roberto , Forgács Attila , Giovenzana Giovanni B. , Tei Lorenzo 
Published: February 2014

AbstractN‐Substituted aminoethyl groups were attached to 1,4,7,10‐tetraazacyclododecane‐1,4,7‐triacetic acid (DO3A) with the aim to design pH‐responsive LnIII complexes based on the pH‐dependent on/off ligation of the amine nitrogen to the metal ion. The following ligands were synthesized: AE‐DO3A (aminoethyl‐DO3A), MAE‐DO3A (N‐methylaminoethyl‐DO3A), DMAE‐DO3A (N,N‐dimethylaminoethyl‐DO3A) and MEM‐AE‐DO3A (N‐methoxyethyl‐N‐methylaminoethyl‐DO3A). The physicochemical properties of the LnIII complexes were investigated for the evaluation of their potential applicability as magnetic resonance imaging (MRI) contrast agents. In particular, a 1H and 17O NMR relaxometric study was carried out for these GdIII complexes at two different pH values: at basic pH (pendant amino group coordinated to the metal centre) and at acidic pH (protonated amine, not interacting with the metal ion). EuIII complexes allow one to estimate the number of inner‐sphere water molecules through luminescence lifetime measurements and obtain some structural information through variable‐temperature (VT) high‐resolution 1H NMR studies. Equilibria between differently hydrated species were found for most of the complexes at both acidic and basic pH. The thermodynamic stability of CaII, ZnII, CuII and LnIII complexes and kinetics of formation and dissociation reactions of LnIII complexes of AE‐DO3A and DMAE‐DO3A were investigated showing stabilities comparable to currently approved GdIII‐based CAs. In detail, higher total basicity (Σlog KiH) and higher stability constants of LnIII complexes were found for AE‐DO3A with respect to DMAE‐DO3A (i.e., log KGd‐AE‐DO3A=22.40 and log KGd‐DMAE‐DO3A=20.56). The transmetallation reactions of GdIII complexes are very slow (Gd‐AE‐DO3A: t1/2=2.7×104 h; Gd‐DMAE‐DO3A: 1.1×105 h at pH 7.4 and 298 K) and occur through proton‐assisted dissociation.
ChemInform Abstract: Na2CaSn2Ge3O12: A Novel Host Lattice for Sm3+‐Doped Long‐Persistent Phosphorescence Materials Emitting Reddish Orange Light.
Authors: Xu Jiao , Ju Zhenghua , Gao Xiuping , An Yanqing , Tang Xiaoliang , Liu Weisheng 
Published: February 2014

AbstractPowder samples of Na2Ca1‐xSn2Ge3O12 :xSm3+ (0 ≤ x ≤ 1.4) are prepared by solid state reactions of Na2CO3, CaCO3, SnO2, GeO2, and Sm2O3 using an equimolar mixture of (NH4)2C2O4 and H3BO3 as flux (alumina crucible, air, 1250 °C, 5 h).
ChemInform Abstract: LiBa1.5[B5O8(OH)3]: A New 1‐D Metal Borate Chain Constructed from B5O9(OH)36‐ Cluster Units.
Authors: Wu Han‐Qing , Yang Bai‐Fei , He Huan , Yang Guo‐Yu 
Published: February 2014

AbstractThe title compound is hydrothermally synthesized from a mixture of Ba(OH)2, H3BO3, Li2CO3, and H2O (autoclave, 200 °C, 7 d, 48% yield).
ChemInform Abstract: A Heterogeneous Layered Bifunctional Catalyst for the Integration of Aerobic Oxidation and Asymmetric C—C Bond Formation.
Authors: Miyamura Hiroyuki , Choo Gerald C. Y. , Yasukawa Tomohiro , Yoo Woo‐Jin , Kobayashi Shu 
Published: February 2014

AbstractA novel layered heterogeneous bifunctional chiral catalyst consisting of bimetallic alloy nanoparticles and a chiral polymer‐supported Jorgensen—Hayashi‐type organocatalyst (POC) is designed, synthesized and successfully applied to the sequential aerobic oxidation—asymmetric Michael reaction of primary allylic alcohols and dibenzyl malonate.
ChemInform Abstract: Regioselective Sulfonylation and N‐ to O‐Sulfonyl Migration of Quinazolin‐4(3H)‐ones and Analogues Thienopyrimidin‐4(3H)‐ones.
Authors: Mertens Matthias D. , Pietsch Markus , Schnakenburg Gregor , Guetschow Michael 
Published: February 2014

AbstractA hydrogen substituent at the 2‐position directs the sulfonyl group to the N‐3 position, while alkylsulfanyl or amino substituents lead to sulfonylation of the carbonyl oxygen.
ChemInform Abstract: A Convenient Catalytic Asymmetric Conjugate Addition Reaction to Enones Using Alkylzirconium Reagents.
Authors: Maksymowicz Rebecca M. , Sidera Mireia , Roth Philippe M. C. , Fletcher Stephen P. 
Published: February 2014

AbstractAlkylmetal species generated in situ from alkenes and the Schwartz reagent undergo enantioselective 1,4‐conjugate addition to enones in the presence of a chiral copper complex as catalyst.
ChemInform Abstract: Visible‐Light‐Induced Intermolecular Atom‐Transfer Radical Addition of Benzyl Halides to Olefins: Facile Synthesis of Tetrahydroquinolines.
Authors: Paria Suva , Pirtsch Michael , Kais Viktor , Reiser Oliver 
Published: February 2014

AbstractRadical addition of nitro‐substituted benzyl halides to silyl enol ethers or styrenes provides ketones or halides which can be easily cyclized to produce tetrahydroquinoline derivatives.
ChemInform Abstract: Gold‐Catalyzed Hydration of Haloalkynes to α‐Halomethyl Ketones.
Authors: Xie Longyong , Wu Yundong , Yi Weiguo , Zhu Lei , Xiang Jiannan , He Weimin 
Published: February 2014

AbstractThe title reaction allows a simple and efficient access to a wide variety of α‐halomethyl ketones.
ChemInform Abstract: Rhodium‐Catalyzed Tandem Cyclopropanation/Cope Rearrangement of 4‐Alkenyl‐1‐sulfonyl‐1,2,3‐triazoles with Dienes.
Authors: Parr Brendan T. , Davies Huw M. L. 
Published: February 2014

AbstractThis method uses 4‐alkenyl‐1,2,3‐triazoles as alkenylcarbene precursors which undergo a formal [4 + 3] cycloaddition to give substituted cycloheptadiene derivatives in high yields and with good enantioselectivities.
ChemInform Abstract: Y(OTf)3 Catalyzed Substitution Dependent Oxidative C(sp3)—C(sp3) Cleavage and Regioselective Dehydration of β‐Allyl‐β‐hydroxydithioesters: Alternate Route to α,β‐Unsaturated Ketones and Functionalized Dienes.
Authors: Chowdhury Sushobhan , Chanda Tanmoy , Nandi Ganesh Chandra , Koley Suvajit , Ramulu B. Janaki , Pandey S. K. , Singh Maya Shankar 
Published: February 2014

AbstractRegioselective addition of allylmagnesium bromide to β‐ketodithioesters (I) produces β‐allyl‐β‐hydroxydithioesters (III).
ChemInform Abstract: Synthesis, Characterization and Catalytic Activity of Sulfonated Multi‐Walled Carbon Nanotubes as Heterogeneous, Robust and Reusable Catalysts for the Synthesis of Bisphenolic Antioxidants under Solvent‐Free Conditions.
Authors: Fareghi‐Alamdari Reza , Golestanzadeh Mohsen , Agend Farima , Zekri Negar 
Published: February 2014

AbstractSulfonated multi‐walled carbon nanotubes prove to be a robust, eco‐friendly, reusable and stable catalyst for the efficient synthesis of bisphenolic antioxidants under solvent‐free conditions.
ChemInform Abstract: Synthesis of Pterostilbene by Julia Olefination.
Authors: Peddikotla Prabhakar , Chittiboyina Amar G. , Khan Ikhlas A. 
Published: February 2014

AbstractA simple synthesis of the biologically active trans‐pterostilbene (VI) from readily available starting materials using a Julia olefination as key step is given.
ChemInform Abstract: Nano n‐Propylsulfonated γ‐Fe2O3: A Novel Magnetically Recyclable Heterogeneous Catalyst for the Efficient Synthesis of Bis(pyrazolyl)methanes in Water.
Authors: Sobhani Sara , Pakdin‐Parizi Zahra , Nasseri Razieh 
Published: February 2014

AbstractThe employed catalyst can be easily isolated from the reaction mixture by a magnetic bar and reused at least five times without significant loss in its activity.
ChemInform Abstract: Asymmetric Formation of tert‐Alkylamines from Serinols by a Dual Function Catalyst.
Authors: You Young Suk , Kim Tae Woo , Kang Sung Ho 
Published: February 2014

AbstractA series of enantiopure oxazolidinones (III), useful tert.‐alkylamine building blocks, is prepared in an one‐pot manner by intramolecular desymmetrization of serinols (I) by a copper‐catalyzed cyclization and a subsequent kinetic resolution of enantiomerically enriched hydroxymethyl‐oxazolidinone intermediates (75—80% e.e.) by a benzoylation.
ChemInform Abstract: Carbene Transfer from Triazolylidene Gold Complexes as a Potent Strategy for Inducing High Catalytic Activity.
Authors: Canseco‐Gonzalez Daniel , Petronilho Ana , Mueller‐Bunz Helge , Ohmatsu Kohsuke , Ooi Takashi , Albrecht Martin 
Published: February 2014

AbstractCatalytically active cationic complexes generated in situ from newly synthesized gold(I) complexes containing triazolylidene ligands in combination with AgBF4 are used as effective catalysts in the reaction of isocyanides and aldehydes to form oxazolines.
ChemInform Abstract: Ionic Liquid‐Mediated Three‐Component Synthesis of Fluorinated Spiro‐Thiazine Derivatives and Their Antimycobacterial and DNA Cleavage Activities.
Authors: Dandia Anshu , Singh Ruby , Saini Deepti 
Published: February 2014

AbstractDNA cleavage studies reveal that the title compounds (IV) and (VI) exhibit promising cleavage activity.
ChemInform Abstract: Concise Stereoselective Total Synthesis of (4R,6R)‐Lactone Moiety Analogue (IV) of Mevinoline and Compactin
Authors: Rao D. Chandra , Reddy D. Kumar , Chinnababu B. , Shekhar V. , Venkateswarlu Y. 
Published: February 2014

Abstract[involving the Corey—Bakshi—Shibata reduction [→ (II)] as a key step].
ChemInform Abstract: Magnetic Interactions in Molecules and Highly Correlated Materials: Physical Content, Analytical Derivation, and Rigorous Extraction of Magnetic Hamiltonians
Authors: Malrieu Jean Paul , Caballol Rosa , Calzado Carmen J. , de Graaf Coen , Guihery Nathalie 
Published: February 2014

AbstractReview: 918 refs.
Production of Nanofibrillated Cellulose by Mechanical Dissociation
Authors: Köster Alexander , Förter‐Barth Ulrich , Herrmann Michael , Schweppe Rainer , Teipel Ulrich 
Published: February 2014

AbstractMithilfe eines zweistufigen Verfahrens, bestehend aus der Dispergierung in Natronlauge und dem anschließenden mechanischen Aufschluss in einer Rührwerkskugelmühle, konnte ein Cellulosevlies in nanoskalige Fibrillen mit Durchmessern im Bereich von einigen nm bis etwa 30 nm aufgeschlossen werden. Dies zeigen auch die Kristallstrukturanalysen, die mit einer tendenziell verfeinerten Kritallitgröße im Bereich der Fibrillendurchmesser auf den Aufschluss der Cellulose in Nanofibrillen hindeuten. Die Faserlänge konnte dabei weitestgehend erhalten bleiben.
Bootstrap methods for imputed data from regression, ratio and hot‐deck imputation
Authors: Mashreghi Zeinab , Léger Christian , Haziza David 
Published: February 2014

AbstractItem non‐response in sample surveys is usually addressed by imputation. A bootstrap method that treats the imputed values as if they were observed generally leads to variance estimates that are too small. Shao & Sitter (1996) introduced a bootstrap method in this context, which leads to consistent variance estimators when the sampling fraction is small. In the context of stratified simple random sampling, we introduce the independent bootstrap, which is valid even when the sampling fraction is large. It consists of modifying a bootstrap method for sample surveys, of independently generating the response status of each unit, and of imputing the non‐respondents in the bootstrap sample. We pay special attention to the bootstrap survey weights approach of Rao, Wu, & Yue (1992). The Canadian Journal of Statistics 42: 142–167; 2014 © 2014 Statistical Society of Canada
Modeling and analyzing the energy consumption of fork‐join‐based task parallel programs
Authors: Rauber Thomas , Rünger Gudula 
Published: February 2014

SUMMARYBecause of environmental and monetary concerns, it is increasingly important to reduce the energy consumption in all areas, including parallel and high performance computing. In this article, we propose an approach to reduce the energy consumption needed for the execution of a set of tasks computed in parallel in a fork‐join fashion. The approach consists of an analytical model for the energy consumption of a parallel computation in fork‐join form on dynamic voltage frequency scaling processors, a theoretical specification of an energy‐optimal frequency‐scaled state, and the energy minimization by computing optimal scaling factors. For larger numbers of tasks, the approach is extended by scheduling algorithms, which exploit the analytical result and aim at a reduction of the energy. Energy measurements of a complex numerical method and the SPEC CPU2006 benchmarks as well as simulations for a large number of randomly generated tasks illustrate and validate the energy modeling, the minimization, and the scheduling results. Copyright © 2014 John Wiley & Sons, Ltd.
Multi‐topology routing based egress selection approach to achieve hybrid intra‐AS and inter‐AS traffic engineering
Authors: Li Ke , Wang Sheng , Xu Shizhong , Wang Xiong , Ren Jin , Huang Haojun , Zhai Bo 
Published: February 2014

SummaryHot‐potato routing is a border gateway protocol policy that selects the ‘closest’ egress router in terms of interior gateway protocol cost. This policy imposes inherent interactions between intra‐AS (Autonomous System) and inter‐AS traffic engineering. In light of this observation, we present a hybrid intra‐AS and inter‐AS traffic engineering scheme named egress selection based upon hot potato routing. This scheme involves link weight optimization, which can not only minimize the time that IP (Internet Protocol) packets travel across the network by assigning specified egress router but also balance the load among the internal links of the transit network. Egress selection based upon hot potato routing also incorporates multi‐topology routing technique to address the problem that one set of link weights might not guarantee specified egress routers. Accordingly, we formulate the link weights optimization problem using multi‐topology routing as a mixed integer linear programming model. And we present a new heuristic algorithm to make the problem tractable. Numerical results show that only a few topologies are needed to guarantee specified egress router, and maximum link utilization is also reduced. Copyright © 2014 John Wiley & Sons, Ltd.
Neural Transplantation Model Using Integration Co‐Culture Chamber
Authors: Shimba Kenta , Saito Atsushi , Takeuchi Akimasa , Takayama Yuzo , Kotani Kiyoshi , Jimbo Yasuhiko 
Published: February 2014

SummaryRegenerative medicine is a promising therapy for injuries and diseases of the central nervous system (CNS). Implantation of stem cell‐derived neurons into the recipient tissue is one of the key processes of the therapy. How the implanted cells establish functional connections with the intact neurons, and whether the established connections are maintained stably for a long time, remain unknown. Here, we report a novel co‐culture device for visualizing interconnections between primary and differentiated neuronal cultures, and long‐term monitoring of neuronal activity. A circular microchamber surrounded by another chamber is aligned on a microelectrode array (MEA). These chambers are interconnected through 36 microtunnels. Stem cell‐derived neurons were cultured in the inner circular chamber, and primary neurons taken from mouse cortices were cultured in the surrounding chamber. Neurites outgrew into the microtunnels from both primary and differentiated neurons. Immunofluorescence images indicated that synaptic connections were formed between them. Propagation of electrical activity was observed 6 days after starting co‐culture. More than half of the spontaneous activity was initiated from primary neurons, and the probability of activity propagation to the stem cell‐derived neurons gradually increased with culture days. These results suggest that our device is feasible for long‐term monitoring of the interaction between stem cell‐derived cells and the recipient tissue.
Decoding of Auditory Information from Steady‐State Neural Activity in Rat Auditory Cortex
Authors: Shiramatsu Tomoyo Isoguchi , Akutsu Kan , Znoda Takahiro , Kanzaki Ryohei , Takahashi Hirokazu 
Published: February 2014

SummaryIn the auditory cortex, auditory‐evoked onset activities have been extensively investigated as a cortical representation of sound information and the emotional information that is associated with sound. However, less attention has been paid to date to steady‐state activities following onset activities. In this study, we used machine learning to investigate whether steady‐state neural activities in the presence of continuous sound represented the sound frequency and the emotion that was associated with the sound. A microelectrode array with a grid of 96 sites recorded local field potentials (LFPs) in the fourth layer of the auditory cortex of anesthetized rats, and sparse logistic regression (SLR) decoded the sound frequency from the steady‐state neural activities of the LFPs. The band‐specific power at every recording site and the phase locking values between every pair of recording sites served as the input vectors for SLR. In addition, we investigated how these decoding accuracies depended on either aversive or appetitive auditory classical conditioning. We found that the SLR was able to decode the sound frequency from the steady‐state neural activities as well as the onset activities and that the decoding accuracy in particular bands either significantly improved or worsened in a conditioning‐dependent manner. These results demonstrated that the steady‐state neural activities contained rich information about not only test sounds but also the emotions that were associated with the sounds.
A Circuit Design Method for Dynamic Reconfigurable Circuits
Authors: Sawano Hajime , Kambe Takashi 
Published: February 2014

SummaryReconfigurable computing (RC) is a new paradigm that addresses the conflicting design requirements of high performance and high area density. Coarse‐grained architecture RC (CGA‐RC) operates at the word level of granularity and exhibits better power and performance features than fine‐grained architectures. However, in a CGA‐RC system, the processing elements (PE) implement several types of arithmetic operations and the routing between them has a fixed architecture. To achieve both good performance and high PE utilization for all applications, this paper proposes an interactive circuit design methodology for dynamically reconfigurable processors to accelerate their performance and achieve compact circuits. The method is applied to a JPEG encoder design and its performance evaluated.
An Anomaly Detection Method for Individual Services on a Web‐Based System by Selection of Dummy Variables in Multiple Regression
Authors: Tsuda Yuki , Samejima Masaki , Akiyoshi Masanori , Komoda Norihisa , Yoshino Matsuki 
Published: February 2014

SUMMARYThis paper addresses the detection of anomalies of individual service from their total resource usage on a web‐based system. Because the total resource usage is a linear combination of the number of accesses to each service, multiple regression analysis can be used to estimate the resource usage per access to each service in the form of regression coefficients. However, the regression coefficients differ from the resource usage per access of the services, due to unstable resource usage per access. We propose a method based on the multiple correlation coefficient R to identify anomaly times and anomaly services. The proposed method identifies an anomaly time when the R value is decreased; it identifies an anomaly service by judging whether R value has increased after the selection of the dummy variable. Experimental results show that the proposed method can identify all anomaly times, and that it improves the precision rate and recall rate of anomaly service detection by at least 20%.