bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reaction Mechanism and the Role of Copper in the Photooxidation of Alcohol over Cu/Nb2O5
Authors: Furukawa Shinya , Ohno Yasuhiro , Shishido Tetsuya , Teramura Kentaro , Tanaka Tsunehiro 
Published: September 2011

AbstractLoading of a small amount of copper on Nb2O5 significantly enhances the activity of alcohol photooxidation without organic solvents. Alcohol is adsorbed on the Lewis acid site (NbV) to form an alkoxide species. Photogenerated holes and electrons on Cu/Nb2O5 are trapped by the adsorbed alkoxide and CuII species to form the alkoxide carbon radical and CuI species. The formed alkoxide carbon radical is converted to a carbonyl compound and then desorbed. Finally, the reduced CuI sites are reoxidized by reaction with O2. The alcohol photooxidation over Nb2O5 takes place under not only UV irradiation but also under visible light irradiation up to 450 nm, although the band gap of Nb2O5 is 390 nm (3.2 eV). DFT calculations reveal that 1) the surface donor level derived from the adsorbed alkoxide species is located in the forbidden band, 2) direct electron transition from the surface donor level to the conduction band takes place by absorbing a photon, 3) the excitation energy from surface donor level to the Nb 4d conduction band is lower than that from the O 2p valence band to Nb 4d. The kinetic study and FT/IR spectra suggest that CuI acts as an effective desorption site for the products. Based on these results, we conclude that copper functions as an effective redox promoter and desorption site for the product.
Substituent Effects on Non‐Covalent Interactions with Aromatic Rings: Insights from Computational Chemistry
Authors: Raju Rajesh K. , Bloom Jacob W. G. , An Yi , Wheeler Steven E. 
Published: September 2011

AbstractNon‐covalent interactions with aromatic rings pervade modern chemical research. The strength and orientation of these interactions can be tuned and controlled through substituent effects. Computational studies of model complexes have provided a detailed understanding of the origin and nature of these substituent effects, and pinpointed flaws in entrenched models of these interactions in the literature. Here, we provide a brief review of efforts over the last decade to unravel the origin of substituent effects in π‐stacking, XH/π, and ion/π interactions through detailed computational studies. We highlight recent progress that has been made, while also uncovering areas where future studies are warranted.
Can We Afford to Waste Carbon Dioxide? Carbon Dioxide as a Valuable Source of Carbon for the Production of Light Olefins
Authors: Centi Gabriele , Iaquaniello Gaetano , Perathoner Siglinda 
Published: September 2011

AbstractConcerns about climate change have increased the amount of activity on carbon capture and sequestration (CCS) as one of the solutions to the problem of rising levels of CO2 in the troposphere, while the reuse of CO2 (carbon capture and recycling; CCR) has only recently received more attention. CCR is focused on the possibility of using CO2 as a cheap (or even negative‐value) raw material. This Concept paper analyzes this possibility from a different perspective: In a sustainable vision, can we afford to waste CO2 as a source of carbon in a changing world faced with a fast depletion of natural carbon sources and in need of a low‐carbon, resource‐efficient economy? One of the points emerging from this discussion concerns the use of CO2 for the production of olefins (substituting into or integrating with current energy‐intensive methodologies that start from oil or syngas from other fossil fuel resources) if H2 from renewable resources were available at competitive costs. This offers an opportunity to accelerate the introduction of renewable energy into the chemical production chain, and thus to improve resource efficiency in this important manufacturing sector.
Mono‐ and Tetraalkyne Modified Ligands and Their Eu3+ Complexes – Utilizing “Click” Chemistry to Expand the Scope of Conjugation Chemistry
Authors: Suchý Mojmír , Milne Mark , Li Alex X. , McVicar Nevin , Dodd David W. , Bartha Robert , Hudson Robert H. E. 
Published: September 2011

AbstractThe Cu+‐catalyzed Huisgen [3+2] cycloaddition has been used to elaborate analogues of a candidate PARACEST MRI contrast agent, which is a complex of Eu3+ with DOTAM–Gly–Phe–OH. Analogues possessing either one L‐tyrosine in place of an L‐phenylalanine, or with all four phenylalanine units replaced, were transformed into Tyr(O‐propargyl) substrates for “click” chemistry. Conjugation of the Eu3+–DOTAM derivatives with a spectrum of azides, including simple hydrophilic, hydrophobic, and aromatic groups, propyl glucoside, and a nucleoside were successful. The magnetic resonance properties of the resultant conjugates were examined, and their chemical exchange saturation transfer (CEST) properties are reported.
Error estimate and adaptive refinement for incompressible Navier‐Stokes equations using the discrete least squares meshless method
Authors: Firoozjaee A.R. , Afshar Mohammad Hadi 
Published: September 2011

SUMMARYIn this paper, an adaptive refinement strategy based on a node‐moving technique is proposed and used for the efficient solution of the steady‐state incompressible Navier–Stokes equations. The value of a least squares functional of the residual of the governing differential equation and its boundary conditions at nodal points is regarded as a measure of error and used to predict the areas of poor solutions. A node‐moving technique is then used to move the nodal points to the zones of higher numerical errors. The problem is then resolved on the refined distribution of nodes for higher accuracy. A spring analogy is used for the node‐moving methodology in which nodal points are connected to their neighbors by virtual springs. The stiffness of each spring is assumed to be proportional to the errors of its two end points and its initial length. The new positions of the nodal points are found such that the spring system attains its equilibrium state. Some numerical examples are used to illustrate the ability of the proposed scheme for the adaptive solution of the steady‐state incompressible Navier–Stokes equations. The results demonstrate a considerable improvement of the results with a reasonable computational effort by using the proposed adaptive strategy. Copyright © 2011 John Wiley & Sons, Ltd.
Shape optimization of steady‐state heat‐conduction fields considering temperature dependency of thermal conductivity coefficient
Authors: Katamine Eiji , Mikada Shingo , Azegami Hideyuki 
Published: September 2011

AbstractThis paper presents a numerical analysis method for shape optimization of domains with steady‐state heat‐conduction fields considering the temperature dependence of the thermal conductivity coefficient. In this paper, we formulate two shape optimization problems, namely, maximization of thermal dissipation on heat transfer boundaries and minimization of heat‐conduction fields. The shape gradient functions for these shape optimization problems are derived theoretically using the Lagrange multiplier method and formulae of the material derivative. Reshaping is accomplished using the traction method proposed as a solution to the shape optimization problems. The proposed method is validated from the results of two‐dimensional numerical analysis. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20374
A mechanism study of initial droplet formation for dropwise condensation
Authors: Liu Tian‐qing , Sun Wei , Mu Chun‐feng , Xia Song‐bai , Sun Xiang‐yu 
Published: September 2011

AbstractThe mechanism of formation of initial condensate droplets for dropwise condensation in the nanometer scale is still undetermined. In this paper, magnesium was used as the condensation surface since it can react with condensate to produce magnesium hydroxide, which can be regarded as the marker of the initial condensate state on the surface. Then an electron probe microanalyzer (EPMA) and scanning electron microscope (SEM) were used to scan the variation of the chemical compositions on the surfaces in nanometer scale before and after the initial condensation. The results showed that the oxygen contents on the test surfaces increased obviously with subcooling and condensation time after the initial dropwise condensation. In order to further analyze the variation of oxygen content occurring on the whole surface or only at the partial locations, the reaction dynamic relationship of magnesium and the condensate was found. And the calculated result indicated that the area ratio occupied by condensate was less than 1. Meanwhile the detected results of EMPA showed that oxygen on the test surface was distributed non‐uniformly. As a result, the formation mechanism of the initial condensate drops for dropwise condensation agrees with the hypothesis of nucleation sites in nanometer scale. © 2011 Wiley Periodicals, Inc. Heat Trans Asian Res; Published online in Wiley Online Library (wileyonlinelibrary.com/journal/htj). DOI 10.1002/htj.20377
Experimental and computational validation and verification of the Stokes–Darcy and continuum pipe flow models for karst aquifers with dual porosity structure
Authors: Hu Xiaolong , Wang Xiaoming , Gunzburger Max , Hua Fei , Cao Yanzhao 
Published: September 2011

AbstractIn our previous study, we developed the Stokes–Darcy (SD) model was developed for flow in a karst aquifer with a conduit bedded in matrix, and the Beavers–Joseph (BJ) condition was used to describe the matrix–conduit interface. We also studied the mathematical well‐posedness of a coupled continuum pipe flow (CCPF) model as well as convergence rates of its finite element approximation. In this study, to compare the SD model with the CCPF model, we used numerical analyses to validate finite element discretisation methods for the two models. Using computational experiments, simulation codes implementing the finite element discretisations are then verified. Further model validation studies are based on the results of laboratory experiments. Comparing the results of computer simulations and experiments, we concluded that the SD model with the Beavers–Joseph interface condition is a valid model for conduit–matrix systems. On the other hand, the CCPF model with the value of the exchange parameter chosen within the range suggested in the literature perhaps does not result in good agreement with experimental observations. We then examined the sensitivity of the CCPF model with respect to the exchange parameter, concluding that, as has previously been noted, the model is highly sensitive for small values of the exchange parameter. However, for larger values, the model becomes less sensitive and, more important, also produces results that are in better agreement with experimental observations. This suggests that the CCPF model may also produce accurate simulation results, if one chooses larger values of the exchange parameter than those suggested in the literature. Copyright © 2011 John Wiley & Sons, Ltd.
Differential biochemical response of rat kidney towards low and high doses of NiCl2 as revealed by NMR spectroscopy
Authors: Tyagi Ritu , Rana Poonam , Gupta Mamta , Khan Ahmad Raza , Bhatnagar Deepak , Bhalla P. J. S. , Chaturvedi Shubhra , Tripathi Rajendra P , Khushu Subash 
Published: September 2011

ABSTRACTHeavy metals are known for their associated nephrotoxicity and nickel is no exception. An integrated metabonomic approach, based on high‐resolution 1H NMR spectroscopy, was applied to determine the acute biochemical effects of NiCl2 on the renal tissues of rats. Kidney homogenates from rats treated with NiCl2 at two dose levels (4 and 20 mg kg−1 b.w., i.p.) and those from controls were analysed using 1H NMR spectroscopy and also assessed for antioxidant parameters at days 1, 3 and 5 post‐dose. The major metabolite changes corresponding to nickel exposure were related to amino acids, osmolytes and energy metabolites. Differential responses were observed in 1H NMR spectra with exposure to low and high doses of NiCl2. For high doses, 1H NMR spectral analysis revealed alterations in renal tissues, along with damage to the cortical and papillary region and depletion of renal osmolytes such as betaine, trimethyl amine oxide, myo‐inositol and taurine, which persisted until day 5 post‐dose. The metabolite profile of 1H NMR spectra obtained from animals treated with lower dose of NiCl2 initially increased as an immediate stress response and then showed signs of recovery with the passage of time. NMR spectral analysis was well corroborated with histopathological and oxidative stress results. Nickel‐induced oxidative stress was observed in both groups of animals with increased levels of antioxidant parameters at initial time points, but continued to increase in the high‐dose group. The present study shows a huge potential of metabonomics for mapping organ‐based metabolic response during heavy metal toxicity. Copyright © 2011 John Wiley & Sons, Ltd.
KLF6/Sp1 initiates transcription of the tmsg‐1 gene in human prostate carcinoma cells: An exon involved mechanism
Authors: Gong Miaozi , Yu Wenjuan , Pei Fei , You Jiangfeng , Cui Xianglin , McNutt Michael A. , Li Gang , Zheng Jie 
Published: September 2011

AbstractThe tumor metastasis suppressor gene‐1 (tmsg‐1) was first cloned as a new tumor suppressor gene in our laboratory several years ago. Since then, however, despite the substantial progression that has been made in investigation of the biologic roles played by this gene, the manner in which it exerts its regulatory influence is still unknown. With transfection of various deletion or mutation constructs, we identified a potential enhancer and three potential silencers in the 5′‐flanking region. However, it was particularly interesting to find that a region (+59 to +123 bp) of exon 1 exhibited a strong role in initiation of tmsg‐1 gene transcription. Deletion of this region led to essentially complete loss of driving activity of exon‐1 sequence on luciferase. Further analysis showed that transcription factors KLF6 and Sp1 are able to interact with each other and bind to their elements in this region. Co‐transfection of pGL3‐114/+123 with KLF6‐ and/or Sp1‐expressing plasmids resulted in an elevation of luciferase activity and transcription level of tmsg‐1, which was abolished by knockdown of KLF6 or Sp1. Analysis of metastatic capacity showed that cells with high metastatic capability exhibited a lower level of KLF6/TMSG‐1 proteins with higher invasive capability and vice versa. Thus, we concluded that interaction of KLF6 and Sp1, together with their binding of elements in exon 1 are critical events in initiation of transcription of the tmsg‐1 gene. These results reveal a hitherto unreported mechanism for initiation of transcription of the tmsg‐1 gene. J. Cell. Biochem. 113: 329–339, 2012. © 2011 Wiley Periodicals, Inc.
Functional characterization of a novel FGFR2 mutation, E731K, in craniosynostosis
Authors: Park Jounghyen , Park Ok‐Jin , Yoon Won‐Joon , Kim Hyun‐Jung , Choi Kang‐Young , Cho Tae‐Joon , Ryoo Hyun‐Mo 
Published: September 2011

AbstractCraniosynostosis is a condition in which some or all of the sutures in the skull of an infant close prematurely. Fibroblast growth factor receptor 2 (FGFR2) mutations are a well‐known cause of craniosynostosis. Many syndromes that comprise craniosynostosis, such as Apert syndrome, Crouzon syndrome, and Pfeiffer syndrome, have one of the phenotypes that have been reported in FGFR2 mutant patients. FGFRs have been reported in four types (FGFR1–4), and upon binding with FGF ligands, signal transduction occurs inside of cells. Activated FGFR stimulates an osteogenic master transcription factor, Runx2, through the MAP kinase and PKC pathways. We obtained a genetic analysis of six Korean patients who have craniosynostosis as a phenotype. All of the patients had at least one mutation in the FGFR2 gene; five of those mutations have already been reported elsewhere, while one mutation is novel and was hypothesized to lead to Apert syndrome. In this study, we reported and functionally analyzed a novel mutation of the FGFR2 gene found in a craniosynostosis patient, E731K. The mutation is in the 2nd tyrosine kinase domain in the C‐terminal cytoplasmic region of the molecule. The mutation caused an enhanced phosphorylation of the FGFR2E731K and ERK‐MAP kinase, the stimulation of transcriptional activity of Runx2, and consequently, the enhancement of osteogenic marker gene expression. We conclude that the substitution of E731K in FGFR2 is a novel mutation that resulted in a constitutive activation of the receptor and ultimately resulted in premature suture obliteration. J. Cell. Biochem. 113: 457–464, 2012. © 2011 Wiley Periodicals, Inc.
Suppression of RANKL‐dependent heme oxygenase‐1 is required for high mobility group box 1 release and osteoclastogenesis
Authors: Sakai Eiko , Shimada‐Sugawara Megumi , Nishishita Kazuhisa , Fukuma Yutaka , Naito Mariko , Okamoto Kuniaki , Nakayama Koji , Tsukuba Takayuki 
Published: September 2011

AbstractThe differentiation of osteoclasts is regulated by several essential cytokines, such as receptor activator of nuclear factor κB ligand (RANKL) and macrophage colony‐stimulating factor. Recently, high mobility group box 1 (HMGB1), a chromatin protein, also has been identified as one of these osteoclast differentiation cytokines. However, the molecular mechanisms that control HMGB1 release from osteoclast precursor cells are not known. Here, we report that RANKL‐induced suppression of heme oxygenase‐1 (HO‐1), a heme‐degrading enzyme, promotes HMGB1 release during osteoclastogenesis. In contrast, induction of HO‐1 with hemin or curcumin in bone marrow‐derived macrophages or RAW‐D murine osteoclast precursor cells inhibited osteoclastogenesis and suppressed HMGB1 release. Since an inhibitor for p38 mitogen‐activated protein kinase (MAPK) prevented the RANKL‐mediated HO‐1 suppression and extracellular release of HMGB1, these effects were p38 MAPK‐dependent. Moreover, suppression of HO‐1 in RAW‐D cells by RNA interference promoted the activation of caspase‐3 and HMGB1 release, whereas overexpression of HO‐1 inhibited caspase‐3 activation as well as HMGB1 release. Furthermore, these effects were regulated by redox conditions since antioxidant N‐acetylcysteine abolished the HO‐1/HMGB1/caspase‐3 axis. These results suggest that RANKL‐dependent HO‐1 suppression leads to caspase‐3 activation and HMGB1 release during osteoclastogenesis. J. Cell. Biochem. 113: 486–498, 2012. © 2011 Wiley Periodicals, Inc.
Multiply balanced edge colorings of multigraphs
Authors: Bahmanian M. A. , Rodger C. A. 
Published: September 2011

AbstractIn this article, a theorem is proved that generalizes several existing amalgamation results in various ways. The main aim is to disentangle a given edge‐colored amalgamated graph so that the result is a graph in which the edges are shared out among the vertices in ways that are fair with respect to several notions of balance (such as between pairs of vertices, degrees of vertices in both the graph and in each color class, etc.). The connectivity of color classes is also addressed. Most results in the literature on amalgamations focus on the disentangling of amalgamated complete graphs and complete multipartite graphs. Many such results follow as immediate corollaries to the main result in this article, which addresses amalgamations of graphs in general, allowing for example the final graph to have multiple edges. A new corollary of the main theorem is the settling of the existence of Hamilton decompositions of the family of graphs K(a1, …, ap; λ1, λ2); such graphs arise naturally in statistical settings. © 2011 Wiley Periodicals, Inc. J Graph Theory 70: 297–317, 2012
Large cliques or stable sets in graphs with no four‐edge path and no five‐edge path in the complement
Authors: Chudnovsky Maria , Zwols Yori 
Published: September 2011

AbstractErdős and Hajnal [Discrete Math 25 (1989), 37–52] conjectured that, for any graph H, every graph on n vertices that does not have H as an induced subgraph contains a clique or a stable set of size nɛ(H) for some ɛ(H)>0. The Conjecture 1. known to be true for graphs H with |V(H)|≤4. One of the two remaining open cases on five vertices is the case where H is a four‐edge path, the other case being a cycle of length five. In this article we prove that every graph on n vertices that does not contain a four‐edge path or the complement of a five‐edge path as an induced subgraph contains either a clique or a stable set of size at least n1/6. © 2011 Wiley Periodicals, Inc. J Graph Theory
Excluding Induced Subdivisions of the Bull and Related Graphs
Authors: Chudnovsky Maria , Penev Irena , Scott Alex , Trotignon Nicolas 
Published: September 2011

AbstractFor any graph H, let Forb*(H) be the class of graphs with no induced subdivision of H. It was conjectured in [J Graph Theory, 24 (1997), 297–311] that, for every graph H, there is a function fH: ℕ→ℝ such that for every graph G∈Forb*(H), χ(G)≤fH(ω(G)). We prove this conjecture for several graphs H, namely the paw (a triangle with a pendant edge), the bull (a triangle with two vertex‐disjoint pendant edges), and what we call a “necklace,” that is, a graph obtained from a path by choosing a matching such that no edge of the matching is incident with an endpoint of the path, and for each edge of the matching, adding a vertex adjacent to the ends of this edge. © 2011 Wiley Periodicals, Inc. J Graph Theory 71:49–68, 2012
Low b‐value diffusion‐weighted imaging for diagnosing strangulated small bowel obstruction: A feasibility study
Authors: Takahara Taro , Kwee Thomas C. , Sadahiro Sotaro , Yamashita Tomohiro , Toyoguchi Yuki , Yoshizako Takeshi , Horie Tomohiro , Luijten Peter R. , Imai Yutaka 
Published: September 2011

AbstractPurpose:To assess the feasibility of low b‐value diffusion‐weighted imaging (DWI) for diagnosing strangulated small bowel obstruction (SBO).Materials and Methods:Five volunteers and 14 patients with SBO underwent DWI at b‐values of 0 and 50 s/mm2. Apparent diffusion coefficients (ADCs) and signal preservation ratios (SPRs) were measured in the distal jejunum in the volunteers before and after butylscopolamine administration, and in the (strangulated) closed loop, near the obstructive site, and far from the obstructive site in the patients. Low b‐value diffusion‐weighted images in the patients were quantitatively evaluated for diagnosing strangulation.Results:In the volunteers, mean ADC (10−3 mm2/s) and SPR (%) before butylscopolamine administration (18.3 ± 5.9 and 41.4 ± 11.5) were significantly different (P < 0.05) from those after butylscopolamine administration (6.4 ± 3.6 and 73.7 ± 12.9). In the patients, mean ADCs and SPRs among the strangulated closed loop (3.8 ± 2.2 and 83.3 ± 9.3), near the obstructive site (12.1 ± 6.9 and 57.3 ± 18.5), and far from the obstructive site (26.8 ± 10.7 and 29.9 ± 16.4) were significantly different (P < 0.05). Areas under the receiver operating characteristic curve for the diagnosis of strangulation varied between 0.937 and 1.000.Conclusion:Low b‐value DWI is a feasible technique to distinguish the strangulated closed loop from nonstrangulated loops in SBO, and show promise for diagnosing strangulated SBO. J. Magn. Reson. Imaging 2011;. © 2011 Wiley Periodicals, Inc.