bluuebunny/crossref_metadata_2025_split huggingface dataset:
Substituent Effects on Structural, Electronic, and Redox Properties of Bis(N‐alkyl‐2‐oxy‐1‐naphthaldiminato)copper(II) Complexes Revisited – Inequivalence in Solid‐ and Solution‐State Structures by Electronic Spectroscopy and X‐ray Diffraction Explained by DFT
Authors: Villagrán Manuel , Caruso Francesco , Rossi Miriam , Zagal José H. , Costamagna Juan 
Published: February 2010

AbstractBis(N‐alkyl‐2‐oxy‐1‐naphthaldiminato)copper(II) complexes in the solid state and in N,N′‐dimethylformamide (DMF) solutions were studied by electronic spectroscopy, X‐ray diffraction, DFT calculations, and cyclic voltammetry. The established correlation between the bulkiness of the imine nitrogen substituent, deformation of the copper coordination sphere, and the CuII/CuI couple potential in DMF solutions has been re‐evaluated, and its inconsistencies explained by using results from DFT calculations and spectroscopic data. According to these DFT calculations, the coordination sphere of the N‐ethyl derivative has a flat‐tetrahedral geometry. The N–Cu–N′ and O–Cu–O′ angles and the dihedral angle between the planes N–Cu–O and N′–Cu–O′ in the solid state found by X‐ray diffraction in this study are affected by crystal packing forces. UV/Vis spectra of the N‐ethyl, N‐iPr, and N‐tBu derivatives suggest that the first two compounds have fluxional behavior characterized by a centrosymmetric transition state, whereas the tBu group in the N‐tBu derivative prevents such dynamic action. In the crystal, this N‐tBu complex changes upon DFT geometry optimization to a more tetrahedral configuration. Therefore, in contrast to X‐ray crystal structures reported in the literature of complexes with primary N‐alkyl substituents that show a planar Cu coordination sphere (i.e. N–Cu–N′ and O–Cu–O′ bond angles of 180°), these complexes are not planar in solution or as isolated molecules.
Volatile, Monomeric, and Fluorine‐Free Precursors for the Metal Organic Chemical Vapor Deposition of Zinc Oxide
Authors: Bekermann Daniela , Rogalla Detlef , Becker Hans‐Werner , Winter Manuela , Fischer Roland A. , Devi Anjana 
Published: February 2010

AbstractTwo new bis(ketoiminato)zinc(II) compounds that show excellent precursor properties for the chemical vapor deposition (CVD) of zinc oxide materials are presented. The synthesis of the ketoiminato zinc complexes [Zn{[(CH2)xOCH3]NC(CH3)=C(H)C(CH3)=O}2] (1: x = 2; 2: x = 3) is straightforward and can easily be scaled up. Compounds 1 and 2 were analyzed by 1H and 13C NMR spectroscopy, elemental analysis, single‐crystal X‐ray diffraction analysis, and electron ionization mass spectrometry. The compounds exist as monomers with a distorted tetrahedral zinc center. Thermogravimetric studies, sublimation, and solubility tests reveal very promising properties for metal–organic CVD related applications. Preliminary metal–organic CVD experiments with the use of compound 1 were performed as a screening for the suitability of the new bis(ketoiminato)zinc complexes as precursors for the growth of ZnO thin films in the presence of oxygen. The films were characterized by X‐ray diffraction, scanning electron microscopy, energy dispersive analysis of X‐ray, and Rutherford backscattering measurements. The as‐deposited ZnO films were stoichiometric; the crystalline films exhibited strong preferred orientation along the c‐axis.
Synthesis and Characterisation of a Novel Chiral Bidentate Pyridine‐N‐Heterocyclic Carbene‐Based Palladacycle
Authors: Chiang Minyi , Li Yongxin , Krishnan Deepa , Sumod Pullarkat , Ng Kim Hong , Leung Pak‐Hing 
Published: February 2010

AbstractA novel chiral six‐membered bidentate pyridine‐N‐heterocyclic carbene palladacycle was prepared via optical resolution of the racemic palladacycle. This is the first successful demonstration of the synthesis of a chiral carbene palladacycle via fractional crystallization of its chiral amino acid derivatives. Upon formation of (RC,SC) and (SC,SC)‐phenylalanate derivatives, the (RC,SC)‐phenylalanate diastereomer crystallized out spontaneously. Optically active (R)‐ and (S)‐dichloropalladacycles can then be achieved by subsequent cleavage of the chiral amino acid auxiliary in the presence of aqueous HCl from their respective diastereomers. The absolute configurations of both the (R)‐ and (S)‐palladacycles were determined by X‐ray diffraction studies.
Titanacalixarenes in Homogeneous Catalysis: Synthesis, Conformation and Catalytic Activity in Ethylene Polymerisation
Authors: Espinas Jeff , Darbost Ulrich , Pelletier Jeremie , Jeanneau Erwan , Duchamp Christian , Bayard François , Boyron Olivier , Broyer Jean‐Pierre , Thivolle‐Cazat Jean , Basset Jean‐Marie , Taoufik Mostafa , Bonnamour Isabelle 
Published: February 2010

AbstractVariously substituted titanacalixarenes were synthesised and tested for their performance as catalysts in ethylene polymerisation: p‐tert‐butylcalix[4]arene was derivatised to afford distal diether p‐tert‐butylcalix[4]arenes L1–L4, distal dihydroxy‐depleted L5, proximal dihydroxy‐depleted L6, proximal diether p‐tert‐butylcalix[4]arene L7, proximal intrabridged disiloxane L8 and proximal monoether L9. (Dichlorotitana)‐p‐tert‐butylcalix[4]arenes 1–8 and (monochlorotitana)‐p‐tertbutylcalix[4]arene 9 have been successfully synthesised by reacting L1–L4 with TiCl4·2THF or L5–L9 with TiCl4. The structural conformation of complexes 1–9 in solution were determined by 1H NMR, 13C NMR, NOESY and COSY spectroscopic studies. Compounds 2, 3 and 4 have been structurally characterised by single‐crystal X‐ray diffraction. Upon activation with methylaluminoxane, compounds 1–8 revealed low to moderate activities for the production of high‐density polyethylene (HDPE) to ultra‐high‐molecular‐weight polyethylene (UHMWPE). 6/MAO gave the best activity at 770 kgPE (mol Ti)–1 h–1.
Palladium‐Catalyzed Intramolecular Aryl Amination Reaction: An Expeditious Approach to the Synthesis of Chiral Benzodiazocine Derivatives
Authors: Adhikary Nirmal Das , Chattopadhyay Partha 
Published: February 2010

AbstractA palladium‐catalyzed method for intramolecular amination of aryl bromides and iodides has been developed employing different bulky biaryl phosphanes as ligands and toluene as solvent. A variety of electron‐rich aryl halide substrates have been aminated by the intramolecular pathway in good yield using different sugar‐derived amines as well as benzylamine. The method is capable of furnishing benzodiazocines in chiral form besides dibenzodiazocine derivatives of potential biological interest.
Simultaneous Determination of Hydroquinone and Catechol at an Activated Glassy Carbon Electrode
Authors: Ahammad A. J. Saleh , Sarker Subrata , Rahman Md Aminur , Lee Jae‐Joon 
Published: February 2010

AbstractA selective and very simple electrochemical method, based on anodization of a glassy carbon electrode (GCE), was developed for the simultaneous detection of hydroquinone (HQ) and catechol (CT). It was found that the activated GCE showed an excellent catalytic behavior and enhanced reversibility towards the oxidation of both HQ and CT. The redox responses from the mixture of HQ and CT were easily resolved at an activated GCE. The detection limits for HQ and CT were calculated to be 0.16 and 0.11 μM, respectively. The activated GCE was successfully examined for real sample analysis with tap water and it showed a stable and reliable recovery data.
Determination of the Apparent Michaelis Constant of Glucose Oxidase Immobilized on a Microelectrode with Respect to Oxygen
Authors: Yasukawa Tomoyuki , Goto Keisuke , Mizutani Fumio 
Published: February 2010

AbstractWe report determination of the apparent Michaelis constant of glucose oxidase (GOx) immobilized on a microelectrode with respect to oxygen. We used a GOx‐modified microelectrode as a probe for scanning electrochemical microscopy. We detected hydrogen peroxide generated by the enzyme reaction at the microelectrode under controlling the oxygen concentration using water electrolysis at an interdigitated array (IDA) electrode. The response depends on the oxygen concentration, which is regulated by the microelectrode position and the potential applied to the IDA electrode. We estimated the apparent Michaelis constant with respect to oxygen in this experimental condition to be about 0.28 mM.
Achiral and chiral separations using MEKC, polyelectrolyte multilayer coatings, and mixed mode separation techniques with molecular micelles
Authors: Luces Candace A. , Warner Isiah M. 
Published: February 2010

AbstractMixed mode (MM) separation using a combination of MEKC and polyelectrolyte multilayer (PEM) coatings is herein reported for the separation of achiral and chiral analytes. Many analytes are difficult to separate by MEKC and PEM coatings alone. Therefore, the implementation of a MM separation provides several advantages for overcoming the limitations of these well‐established methods. In this study, it was observed that achiral separations using MEKC and PEM coatings individually resulted in partial resolution of eight very similar aryl ketones when the molecular micelle (sodium poly(N‐undecanoyl‐L‐glycinate)) concentration was varied from 0.25 to 1.00% w/v and the bilayer number varied from 2 to 4. However, when MM separation was introduced, baseline resolution was achieved for all eight analytes. In the case of chiral separations, temazepam, aminoglutethimide, benzoin, benzoin methyl ether, and coumachlor were separated using the three separation techniques. For chiral separations, the chiral molecular micelle, sodium poly(N‐undecanoyl‐L‐leucylvalinate), was employed at concentrations of 0.25–1.50% w/v for both MEKC and PEM coatings. Overall, the results revealed partial separation with MEKC and PEM coatings individually. However, MM separation enabled baseline separation of each chiral mixture. The separation of achiral and chiral compounds from different compound classes demonstrates the versatility of this MM approach.
Analysis of phenolic xenoestrogens by pressurized CEC with amperometric detection
Authors: Wu Weimin , Yuan Xiaomei , Wu Xiaoping , Lin Xucong , Xie Zenghong 
Published: February 2010

AbstractA new method, pressurized CEC with end‐column amperometric detection using carbon paste electrode, has been developed for the separation and determination of five phenolic xenoestrogens in chicken eggs and milk powder samples. Efficient separation of five analytes was performed by pressurized CEC using a mobile phase consisting of 60% v/v ACN and 40% v/v Tris buffer (5 mmol/L, pH 8.0), +6 kV of applied voltage and 7.0 MPa of supplementary pressure. Detection limits of 50, 5, 2, 10 and 20 ng/mL for pentachlorophenol, bisphenol‐A, 2,4‐dichlorophenol, 4‐tert‐octylphenol and 4‐nonylphenol, respectively, were achieved using carbon paste electrode as working electrode and +0.8 V as detection potential. Matrix solid phase dispersion extraction method had been employed during sample preparation procedure, and mean recoveries ranged from 79.2 to 102.6% at different concentrations of phenolic xenoestrogens for spiked egg and milk powder samples were obtained.
Some examples of the communication of risk and uncertainty
Authors: Brillinger David R. 
Published: February 2010

AbstractDefinitions are set down and results of analyses of communication of risk and uncertainty are presented for the fields of wildfires, earthquakes and space debris. These are all fields of some societal importance. Also there is discussion of methods of evaluating and displaying estimates of risk estimates' uncertainty. Copyright © 2010 John Wiley & Sons, Ltd.
Relevance of octanol–water distribution measurements to the potential ecological uptake of multi-walled carbon nanotubes
Authors: Petersen Elijah J. , Huang Qingguo , Weber Walter J. 
Published: February 2010

AbstractMany potential applications of carbon nanotubes (CNTs) require various physicochemical modifications prior to use, suggesting that nanotubes having varied properties may pose risks in ecosystems. A means for estimating bioaccumulation potentials of variously modified CNTs for incorporation in predictive fate models would be highly valuable. An approach commonly used for sparingly soluble organic contaminants, and previously suggested for use as well with carbonaceous nanomaterials, involves measurement of their octanol–water partitioning coefficient (KOW) values. To test the applicability of this approach, a methodology was developed to measure apparent octanol–water distribution behaviors for purified multi-walled carbon nanotubes and those acid treated. Substantial differences in apparent distribution coefficients between the two types of CNTs were observed, but these differences did not influence accumulation by either earthworms (Eisenia foetida) or oligochaetes (Lumbriculus variegatus), both of which showed minimal nanotube uptake for both types of nanotubes. The results suggest that traditional distribution behavior-based KOW approaches are likely not appropriate for predicting CNT bioaccumulation. Environ. Toxicol. Chem. 2010;29:1106–1112. © 2010 SETAC
Schwann cell migration is integrin‐dependent and inhibited by astrocyte‐produced aggrecan
Authors: Afshari Fardad T. , Kwok Jessica C. , White Linda , Fawcett James W. 
Published: February 2010

AbstractSchwann cells transplantation has considerable promise in spinal cord trauma to bridge the site of injury and for remyelination in demyelinating conditions. They support axonal regeneration and sprouting by secreting growth factors and providing a permissive surface and matrix molecules while shielding axons from the inhibitory environment of the central nervous system. However, following transplantation Schwann cells show limited migratory ability and they are unable to intermingle with the host astrocytes. This in turn leads to formation of a sharp boundary and an abrupt transition between the Schwann cell graft and the host tissue astrocytes, therefore preventing regenerating axons from exiting the graft. The objective of this study was to identify inhibitory elements on astrocytes involved in restricting Schwann cell migration. Using in vitro assays of cell migration, we show that aggrecan produced by astrocytes is involved in the inhibition of Schwann cell motility on astrocytic monolayers. Knockdown of this proteoglycan in astrocytes using RNAi or digestion of glycosaminglycan chains on aggrecan improves Schwann cell migration. We further show aggrecan mediates its effect by disruption of integrin function in Schwann cells, and that the inhibitory effects of aggrecan can overcome by activation of Schwann cell integrins. © 2010 Wiley‐Liss, Inc.
Triptolide promotes spinal cord repair by inhibiting astrogliosis and inflammation
Authors: Su Zhida , Yuan Yimin , Cao Li , Zhu Yanling , Gao Liang , Qiu Yang , He Cheng 
Published: February 2010

AbstractSpinal cord injury (SCI) is a cause of major neurological disability, and no satisfactory treatment is currently available. Traumatic SCI directly damages the cell bodies and/or processes of neurons and triggers a series of endogenous processes, including neuroinflammatory response and reactive astrogliosis. In this study, we found that triptolide, one of the major active components of the traditional Chinese herb Tripterygium wilfordii Hook F, inhibited astrogliosis and inflammation and promoted spinal cord repair. Triptolide was shown to prevent astrocytes from reactive activation by blocking the JAK2/STAT3 pathway in vitro and in vivo. Furthermore, astrocytic gliosis and glial scar were greatly reduced in injured spinal cord treated with triptolide. Triptolide treatment was also shown to decrease the ED‐1 or CD11b‐positive inflammatory cells at the lesion site. Using neurofilament staining and anterograde tracing, a significantly greater number of regenerative axons were observed in the triptolide‐treated rats. Importantly, behavioral tests revealed that injured rats receiving triptolide had improved functional recovery as assessed by the Basso, Beattie, and Bresnahan open‐field scoring, grid‐walk, and foot‐print analysis. These results suggested that triptolide promoted axon regeneration and locomotor recovery by attenuating glial scaring and inflammation, and shed light on the potential therapeutic benefit for SCI. © 2010 Wiley‐Liss, Inc.
Genetic ablation of steroid receptor coactivator‐3 promotes PPAR‐β‐mediated alternative activation of microglia in experimental autoimmune encephalomyelitis
Authors: Xiao Yichuan , Xu Jingwei , Wang Shu , Mao Chaoming , Jin Min , Ning Guang , Xu Jianming , Zhang Yanyun 
Published: February 2010

AbstractSteroid receptor coactivator‐3 (SRC‐3) has been demonstrated to regulate lipid metabolism by inhibiting adipocyte differentiation. In this study, the potential role of SRC‐3 in experimental autoimmune encephalomyelitis (EAE), which characterized by inflammatory demyelination in central nervous system (CNS), was examined by analyzing disease progression in SRC‐3‐deficient (SRC‐3−/−) mice. We found that SRC‐3 deficiency significantly attenuated the disease severity of EAE along with decreased inflammatory infiltration and demyelination. However, these effects are not caused by inhibition of peripheral T cell response, but by upregulated expression of peroxisome proliferator‐activated receptor (PPAR)‐β in CNS, which induced an alternative activation state of microglia in SRC‐3−/− mice. These alternatively activated microglia inhibited CNS inflammation through inhibition of proinflammatory cytokines and chemokines, such as TNF‐α, IFN‐γ, CCL2, CCL3, CCL5, and CXCL10, as well as upregulation of anti‐inflammatory cytokine IL‐10 and opsonins, such as C1qa and C1qb. Moreover, microglia alternative activation promoted myelin regeneration through increased accumulation of oligodendrocyte precursors in white matter and elevated expression of myelin genes in the spinal cords of SRC‐3−/− mice. Our results build up a link between lipid metabolic regulation and immune functions, and the modulation of the expression of SRC‐3 or PPAR‐β may hopefully has therapeutic modality in MS and possibly other neurodegenerative diseases. © 2010 Wiley‐Liss, Inc.
An Fgfr3‐iCreERT2 transgenic mouse line for studies of neural stem cells and astrocytes
Authors: Young Kaylene M. , Mitsumori Tomoyuki , Pringle Nigel , Grist Matthew , Kessaris Nicoletta , Richardson William D. 
Published: February 2010

AbstractThe lack of markers for astrocytes, particularly gray matter astrocytes, significantly hinders research into their development and physiological properties. We previously reported that fibroblast growth factor receptor 3 (Fgfr3) is expressed by radial precursors in the ventricular zone of the embryonic neural tube and subsequently by differentiated astrocytes in gray and white matter. Here, we describe an Fgfr3‐iCreERT2 phage artificial chromosome transgenic mouse line that allows efficient tamoxifen‐induced Cre recombination in Fgfr3‐expressing cells, including radial glial cells in the embryonic neural tube and both fibrous and protoplasmic astrocytes in the mature central nervous system. This mouse strain will therefore be useful for studies of normal astrocyte biology and their responses to CNS injury or disease. In addition, Fgfr3‐iCreERT2 drives Cre recombination in all neurosphere‐forming stem cells in the adult spinal cord and at least 90% of those in the adult forebrain subventricular zone. We made use of this to show that there is continuous accumulation of all major interneuron subtypes in the olfactory bulb (OB) from postnatal day 50 (P50) until at least P230 (∼8 months of age). It therefore seems likely that adult‐born interneurons integrate into existing circuitry and perform long‐term functions in the adult OB. © 2010 Wiley‐Liss, Inc.
Vav‐1 expression correlates with NFκB activation and CD40‐mediated cell death in diffuse large B‐cell lymphoma cell lines
Authors: Hollmann Annette , Aloyz Raquel , Baker Kristi , Dirnhofer Stephan , Owens Trevor , Sladek Robert , Tzankov Alexandar 
Published: February 2010

AbstractDiffuse large B‐cell lymphoma (DLBCL) is an aggressive malignancy with a variable response to therapy. We have previously shown that DLBCL cell lines differ in their susceptibility to CD40‐mediated cell death, and that resistance to CD40‐targeted antibodies correlated with increased expression of markers of immature B‐cell and absence of Vav‐1 mRNA. We used gene expression profiling to investigate the mechanism of CD40 resistance in these cell lines, and found that resistance correlated with lack of Vav‐1 and inability to activate NFκB upon CD40 ligation. Analysis of tissue microarrays of 213 DLBCL cases revealed that Vav‐1 expression correlated with a higher proliferative index and the presence of the post‐germinal centre marker Irf‐4. Our results suggest that Vav‐1 expression may be associated with activated B‐cell DLBCL origin and higher proliferative activity, and indicate Vav‐1 as a potential marker to identify tumours likely to respond to CD40‐targeted therapies. Copyright © 2010 John Wiley & Sons, Ltd.
Leaf Quality of Some Tropical and Temperate Tree Species as Food Resource for Stream Shredders
Authors: Graça Manuel A. S. , Cressa Claudia 
Published: February 2010

AbstractWe tested the hypotheses that (1) plant defenses against consumers increase in the tropics, and that these differences in quality are perceived by detritivores; and (2) microbial conditioning of leaf litter is important for the feeding ecology of shredders from both geographical regions. We compared quality parameters of 8 tree species from Portugal and 8 from Venezuela. The tropical leaves were tougher, but did not differ from temperate leaves in terms of N, C: N, and polyphenols. In multiple‐choice experiments, shredders from Portugal (Sericostoma vittatum and Chaetopteryx lusitanica) and from Venezuela (Nectopsyche argentata and Phylloicus priapulus) discriminated among conditioned leaves, preferentially consuming softer leaves. In another set of experiments, all shredders preferentially fed on conditioned rather than unconditioned leaves, grew faster when fed conditioned than unconditioned leaves and fed more on temperate than tropical leaves. We conclude that leaf litter from the tropics is a low‐quality resource compared to leaves in temperate systems, because of differences in toughness, and that tropical shredders benefit from microbial colonization, as previously demonstrated for temperate systems. We suggest that leaf toughness could be one explanation for the reported paucity of shredders in some tropical streams. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Effects of Zn, Fe and Mn on Leaf Litter Breakdown by Aquatic Fungi: a Microcosm Study
Authors: Medeiros Adriana , Duarte Sofia , Pascoal Cláudia , Cássio Fernanda , Graça Manuel 
Published: February 2010

AbstractWe investigated the effects of heavy metals on leaf litter decomposition in streams. Leaves were immersed (10 days) at a reference (R) and a metal‐impacted (I) site and exposed in microcosms with increased Zn, Mn or Fe content, and to stream water from site R or I. Fungal biomass was higher in microcosms with leaves colonized at I and water from R. Fungal sporulation was higher in microcosms with leaves and water from R. Concentrations of 4.9, 9.6 and 5 ppm of Zn, Mn and Fe decrease fungal sporulation. The number of fungal species (spore counts and DGGE fingerprints) was lower in leaves colonized at site I. Cluster analyses of DGGE showed that Fe was the metal that most altered the structure of fungal community. Our results suggest that metal pollution affect leaf‐associated fungi depending on metal identity and concentration, and effects appear to be less pronounced in metal‐adapted communities. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)