bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cover Picture: An Organic Light‐Emitting Diode with Field‐Effect Electron Transport (Adv. Funct. Mater. 1/2008)
Authors: Schols S. , Verlaak S. , Rolin C. , Cheyns D. , Genoe J. , Heremans P. 
Published: January 2008

AbstractThe cover shows an organic light‐emitting diode with remote metallic cathode, reported by Sarah Schols and co‐workers on p. 136. The metallic cathode is displaced from the light‐emission zone by one to several micrometers. The injected electrons accumulate at an organic heterojunction and are transported to the light‐emission zone by field‐effect. The achieved charge‐carrier mobility and in combination with reduced optical absorption losses because of the remoteness of the cathode may lead to applications as waveguide OLEDs and possibly a laser structure. (The result was obtained in the EU‐funded project “OLAS” IST‐ FP6‐015034.)We describe an organic light‐emitting diode (OLED) using field‐effect to transport electrons. The device is a hybrid between a diode and a field‐effect transistor. Compared to conventional OLEDs, the metallic cathode is displaced by one to several micrometers from the light‐emitting zone. This micrometer‐sized distance can be bridged by electrons with enhanced field‐effect mobility. The device is fabricated using poly(triarylamine) (PTAA) as the hole‐transport material, tris(8‐hydroxyquinoline) aluminum (Alq3) doped with 4‐(dicyanomethylene)‐2‐methyl‐6‐(julolindin‐4‐yl‐vinyl)‐4H‐pyran (DCM2) as the active light‐emitting layer, and N,N′‐ditridecylperylene‐3,4,9,10‐tetracarboxylic diimide (PTCDI‐C13H27), as the electron‐transport material. The obtained external quantum efficiencies are as high as for conventional OLEDs comprising the same materials. The quantum efficiencies of the new devices are remarkably independent of the current, up to current densities of more than 10 A cm–2. In addition, the absence of a metallic cathode covering the light‐emission zone permits top‐emission and could reduce optical absorption losses in waveguide structures. These properties may be useful in the future for the fabrication of solid‐state high‐brightness organic light sources.
Inside Front Cover: Green Synthesis and Property Characterization of Single‐Crystalline Perovskite Fluoride Nanorods (Adv. Funct. Mater. 1/2008)
Authors: Zhang F. , Mao Y. , Park T.‐J. , Wong S. S. 
Published: January 2008

AbstractThe synthesis of single‐crystalline, cubic perovskite KMnF3 and NH4MnF3 nanorods, and their rare‐earth‐ion‐doped analogues with reproducible shapes and sizes, has been realized using a modified template‐directed approach, report Stanislaus Wong and co‐workers on p. 103. The properties of the nanorods and their as‐doped counterparts suggest their practical incorporation into functional nanometer‐scale devices with applications in a number of fields. The cover shows the crystal structure of perovskite fluorides overlaid on a SEM image of as‐prepared KMnF3 nanorods with diameters measuring around 50 nm.The generalized green synthesis of single‐crystalline KMnF3 and NH4MnF3 nanorods as well as of their rare‐earth ion doped analogues, possessing reproducible shape and controllable size, has been achieved using a modified template‐directed approach under ambient room‐temperature conditions, with simple inorganic salts as functional precursors. Extensive characterization of the resulting nanorods has been performed using diffraction, electron microscopy, optical spectroscopy, as well as magnetic techniques. We have studied the antiferromagnetism of as‐prepared ternary metal fluoride nanorods as well as the luminescence of their as‐doped counterparts. Our collective data suggest the possibility of the incorporation of these high‐quality, chemically pure materials into functional nanoscale devices with various potential applications that exploit the interesting optomagnetic properties of these systems.
Evaluation of Different Glutaryl Acylase Mutants to Improve the Hydolysis of Cephalosporin C in the Absence of Hydrogen Peroxide
Authors: López‐Gallego Fernando , Betancor Lorena , Sio Charles F. , Reis Carlos R. , Jimenez Pol Nadal , Guisan Jose M. , Quax Wim. J. , Fernandez‐Lafuente Roberto 
Published: January 2008

Abstract2‐Oxoadipoyl‐7‐ACA is an intermediate in the conversion of cephalosporin C (CPC) to 7‐aminocephalosporanic acid (7‐ACA) when using a new route involving D‐amino acid oxidase, catalase and glutaryl acylase. A key point in the reaction design is to avoid the accumulation of hydrogen peroxide in the reaction medium as the yields of 7‐ACA decrease in the presence of this compound due to its low stability. Looking for an enzyme with improved activity towards 2‐oxoadipoyl‐7‐ACA, different mutants of glutaryl acylase from Pseudomonas SY‐77 with an improved activity towards adipoyl‐7‐ACA were evaluated. The best results on 2‐oxoadipoyl‐7‐ACA hydrolysis were found with the double mutant Y178F+F375H, which showed a Kcat increase of 6.5‐fold and a Km decrease of 3‐fold compared to the wild‐type (wt) enzyme. When this enzyme was tested in the tri‐enzymatic system to convert CPC into 7‐ACA, this mutant permitted us to reach more than an 80 % yield of 7‐ACA using a 3‐fold mass excess compared to DAAO; while the wt enzyme gave only a 40 % yield. Therefore, the application of this new mutant to the one‐pot conversion of CPC to 7‐ACA gives very good result in terms of efficiency, yield and rate of the process.
Engineering Polymer‐Enhanced Bimetallic Cooperative Interactions in the Hydrolytic Kinetic Resolution of Epoxides
Authors: Zheng Xiaolai , Jones Christopher W. , Weck Marcus 
Published: January 2008

AbstractThrough systematic variations of the length of oligo(ethylene glycol)‐based linkers and the catalyst density of poly(styrene)‐supported cobalt‐salen catalysts, we have elucidated an optimal catalyst flexibility and density of polymeric Co‐salen catalysts for the hydrolytic kinetic resolution (HKR) of racemic terminal epoxides that follows a bimetallic cooperative pathway. The optimized polymeric catalyst brings the two cooperative Co‐salen units to a favorable proximity efficiently and hence displays significantly improved catalytic performance in the HKR compared with its monomeric small molecule analogue. Complex Co(5b), representing the most active poly(styrene)‐supported HKR catalyst known so far, can effect the resolution of a variety of epoxides to reach ≥98 % ee in 6–24 h with a low cobalt loading of 0.01–0.1 mol %.
Palladium(II)‐Catalyzed One‐Pot Enantioselective Synthesis of Arylglycine Derivatives from Ethyl Glyoxylate, p‐Toluenesulfonyl Isocyanate and Arylboronic Acids
Authors: Dai Huixiong , Yang Miao , Lu Xiyan 
Published: January 2008

AbstractA palladium(II)‐catalyzed, one‐pot enantioselective synthesis of arylglycine derivatives from ethyl glyoxylate, p‐toluenesulfonyl isocyanate and arylboronic acids giving moderate to good yields and enantioselectivity has been developed. This reaction provides a convenient and efficient method for the synthesis of arylglycines.
An Unprecedented Iridium(III) Catalyst for Stereoselective Dimerisation of Terminal Alkynes
Authors: Ciclosi Marco , Estevan Francisco , Lahuerta Pascual , Passarelli Vincenzo , Pérez‐Prieto Julia , Sanaú Mercedes 
Published: January 2008

AbstractA novel iridium(III) hydride complex, IrHCl(TIMP3) {HTIMP3=tris[1‐(diphenylphosphino)‐3‐methyl‐1H‐indol‐2‐yl]methane} was prepared and fully characterized in both the solid state and in solution. Chloride abstraction by silver cations provides a more reactive compound, [IrH(TIMP3)][BF4], which can react with pyridine (py) and phenylacetylene to yield the complexes [IrH(TIMP3)(py)][BF4] and [Ir(PhCHCCHCHPh)(TIMP3)][BF4], respectively. Interestingly, IrH(TIMP3)(py)][BF4] efficiently catalyses the stereoselective dimerisation of model terminal alkynes to the 1,4‐disubstituted (E)‐but‐1‐en‐3‐yne only.
Comparing ape densities and habitats in northern Congo: surveys of sympatric gorillas and chimpanzees in the Odzala and Ndoki regions
Authors: Devos Céline , Sanz Crickette , Morgan David , Onononga Jean‐Robert , Laporte Nadine , Huynen Marie‐Claude 
Published: January 2008

AbstractThe conservation status of western lowland gorillas and central chimpanzees in western equatorial Africa remains largely speculative because many remote areas have never been surveyed and the impact of emergent diseases in the region has not been well documented. In this study, we compared ape densities and habitats in the Lokoué study area in Odzala National Park and the Goualougo Triangle in Nouabalé‐Ndoki National Park in northern Republic of Congo. Both of these sites have long been considered strongholds for the conservation of chimpanzees and gorillas, but supposedly differ in vegetative composition and relative ape abundance. We compared habitats between these sites using conventional ground surveys and classified Landsat‐7 ETM+ satellite images. We present density estimates via both standing‐crop and marked‐nest methods for the first time for sympatric apes of the Congo Basin. The marked‐nest method was effective in depicting chimpanzee densities, but underestimated gorilla densities at both sites. Marked‐nest surveys also revealed a dramatic decline in the ape population of Lokoué which coincided with a local Ebola epidemic. Normal baseline fluctuations in ape nest encounter rates during the repeated passages of marked‐nest surveys were clearly distinguishable from a 80% decline in ape nest encounter rates at Lokoué. Our results showed that ape densities, habitat composition, and population dynamics differed between these populations in northern Congo. We emphasize the importance of intensifying monitoring efforts and further refinement of ape survey methods, as our results indicated that even the largest remaining ape populations in intact and protected forests are susceptible to sudden and dramatic declines. Am. J. Primatol. 70:439–451, 2008. © 2008 Wiley‐Liss, Inc.
Pharmacokinetics and metabolism of intravenous pirfenidone in sheep
Authors: Bruss Michael L. , Stanley Scott D. , Margolin Solomon B. , Giri Shri N. 
Published: January 2008

AbstractPirfenidone, a promising antifibrotic agent, was administered intravenously to six female sheep at 30 mg/kg. Four sheep received 14C‐pirfenidone simultaneously. Plasma and urine were obtained for assay of pirfenidone and its metabolites over two days, and tissues were obtained via necropsy. Samples were analysed for pirfenidone and metabolites using HPLC‐MS and flow scintillation spectrometry. Plasma pirfenidone disappeared with first order kinetics with a clearance of 1.2 l/kg/h, half‐life of 24 min, and distribution volume of 0.71 l/kg. After 48 h, the organs containing the largest quantity of 14C were lungs, liver and intestinal wall. Tissues with the highest concentration of 14C were lung, kidney, brain, liver, lymph node and adipose. Metabolites found in plasma and urine were hydroxypirfenidone (half‐life of 44 min) and carboxypirfenidone. Additional metabolites found in urine were hydroxypirfenidone glucuronide and acetoxypirfenidone. Approximately, 80% of the tracer eventually appeared in the urine, and approximately 50% of it was in the form of identifiable metabolites. Less than 1% of the dose appeared in the urine in the form of the parent drug. Quantitatively, most of the metabolites appeared in the urine within 2 h. Thus, the drug is rapidly and completely metabolized. Copyright © 2008 John Wiley & Sons, Ltd.
Synthesis and luminescent properties of a novel bluish‐white afterglow phosphor, b‐Zn3(PO4)2:Hf4+
Authors: Peng Zifei , Xu Zhu , Luo Caiqin , Yu Junbao , Zhang Guobin 
Published: January 2008

AbstractA new bluish‐white long‐lasting phosphorescent material, Hf4+‐doped b‐Zn3(PO4)2, was prepared by the conventional high‐temperature solid‐state method. The photoluminescence (PL) spectrum reveals that it exhibits a strong blue emission band centred at 470 nm, with asymmetry on the long wavelength side; this material emits bluish‐white light and shows strong afterglow phosphorescence after it is excited with a 254 nm UV lamp. The phosphorescence lasts nearly 40 min in the light perception of the dark‐adapted human eye (0.32 mcd/m2). The possible phosphorescence mechanism is also analysed. Copyright © 2008 John Wiley & Sons, Ltd.
Redirection of flux through the FPP branch‐point in Saccharomyces cerevisiae by down‐regulating squalene synthase
Authors: Paradise Eric M. , Kirby James , Chan Rossana , Keasling Jay D. 
Published: January 2008

AbstractSaccharomyces cerevisiae utilizes several regulatory mechanisms to maintain tight control over the intracellular level of farnesyl diphosphate (FPP), the central precursor to nearly all yeast isoprenoid products. High‐level production of non‐native isoprenoid products requires that FPP flux be diverted from production of sterols to the heterologous metabolic reactions. To do so, expression of the gene encoding squalene synthase (ERG9), the first committed step in sterol biosynthesis, was down‐regulated by replacing its native promoter with the methionine‐repressible MET3 promoter. The intracellular levels of FPP were then assayed by expressing the gene encoding amorphadiene synthase (ADS) and converting the FPP to amorphadiene. Under certain culture conditions amorphadiene production increased fivefold upon ERG9 repression. With increasing flux to amorphadiene, squalene and ergosterol production each decreased. The levels of these three metabolites were dependent not only upon the level of ERG9 repression, but also the timing of its repression relative to the induction of ADS and genes responsible for enhancing flux to FPP. Biotechnol. Bioeng. 2008;99: 371–378. © 2007 Wiley Periodicals, Inc.
Carbon‐Centered Radical Addition and β‐Scission Reactions: Modeling of Activation Energies and Pre‐exponential Factors
Authors: Sabbe Maarten K. , Reyniers Marie‐Françoise , Van Speybroeck Veronique , Waroquier Michel , Marin Guy B. 
Published: January 2008

AbstractA consistent set of group additive values ΔGAV° for 46 groups is derived, allowing the calculation of rate coefficients for hydrocarbon radical additions and β‐scission reactions. A database of 51 rate coefficients based on CBS‐QB3 calculations with corrections for hindered internal rotation was used as training set. The results of this computational method agree well with experimentally observed rate coefficients with a mean factor of deviation of 3, as benchmarked on a set of nine reactions. The temperature dependence on the resulting ΔGAV°s in the broad range of 300–1300 K is limited to ±4.5 kJ mol−1 on activation energies and to ±0.4 on logA (A: pre‐exponential factor) for 90 % of the groups. Validation of the ΔGAV°s was performed for a test set of 13 reactions. In the absence of severe steric hindrance and resonance effects in the transition state, the rate coefficients predicted by group additivity are within a factor of 3 of the CBS‐QB3 ab initio rate coefficients for more than 90 % of the reactions in the test set. It can thus be expected that in most cases the GA method performs even better than standard DFT calculations for which a deviation factor of 10 is generally considered to be acceptable.
A Pragmatic Recipe for the Treatment of Hindered Rotations in the Vibrational Averaging of Molecular Properties
Authors: Mort Brendan C. , Autschbach Jochen 
Published: January 2008

AbstractA computational protocol for the treatment of hindered rotations in the vibrational averaging of molecular properties is described. As examples, the specific rotations ${[\alpha ]_{\rm{D}} }$ of (R)‐methyloxirane, (1S)‐methylnorbornanone, and (S)‐epichlorohydrin and the spin‐spin coupling constant ${J_{{\rm{HD}}} }$ for ${[Ir(Cp)(PMe_3 )H_2 ]^ + }$ are investigated. For each of the four molecules, the relaxed and unrelaxed potential energy surfaces along the rotational coordinate of interest are used to solve the nuclear Schrödinger equation using a pseudospectral method. Analysis of the results demonstrate that the vibrational averaging for low‐frequency modes that represent hindered rotations can lead to unphysical behavior at high temperatures while simply neglecting the rotational contributions is also not desirable. The method described in this work connects the (an)harmonic oscillator behavior at low temperatures with the free rotor‐like behavior at high temperatures.
Coupled choosability of plane graphs
Authors: Wang Weifan , Lih Ko‐Wei 
Published: January 2008

AbstractA plane graph G is coupled k‐choosable if, for any list assignment L satisfying $|{{L}}({{x}})|= {{k}}$ for every ${{x}}\in {{V}}({{G}})\cup {{F}}({{G}})$, there is a coloring that assigns to each vertex and each face a color from its list such that any two adjacent or incident elements receive distinct colors. We prove that every plane graph is coupled 7‐choosable. We further show that maximal plane graphs, ${{K}}_{{4}}$‐minor free graphs, and plane graphs with maximum degree at most three are coupled 6‐choosable. © 2008 Wiley Periodicals, Inc. J Graph Theory 58: 27–44, 2008
Expression of CXCL12 and its receptor CXCR4 correlates with lymph node metastasis in submucosal esophageal cancer
Authors: Sasaki Ken , Natsugoe Shoji , Ishigami Sumiya , Matsumoto Masataka , Okumura Hiroshi , Setoyama Tetsuro , Uchikado Yasuto , Kita Yoshiaki , Tamotsu Kiyokazu , Sakurai Toshihide , Owaki Tetsuhiro , Aikou Takashi 
Published: January 2008

AbstractBackground and ObjectivesThe chemokine CXCL12 and its receptor CXCR4 are involved in cell migration, proliferation, and angiogenesis, and promote organ‐specific localization of distant metastases in various carcinomas. We examined their expression and microvessel density (MVD) in submucosal esophageal squamous cell carcinoma (ESCC) and analyzed their connection to clinicopathological findings including lymph node micrometastasis (LMM).MethodsEighty‐six patients with submucosal ESCC underwent curative resection from 1985 to 2002. Immunohistochemical staining of CXCL12, CXCR4, and CD34 was performed with primary tumors, and staining of cytokeratin was performed with dissected lymph nodes. MVD was calculated from CD34 expression, and LMM detected by cytokeratin staining.ResultsExpression of CXCL12, but not CXCR4, correlated with lymph node metastasis. There was no significant correlation between the expression of CXCL12 and/or CXCR4 and MVD. LMM was detected in 8 cases and 14 lymph nodes. CXCL12 expression and high MVD were found in tumors with lymph node metastasis including LMM. Furthermore, in the CXCR4‐positive tumors, positive CXCL12 expression was more significantly correlated with lymph node metastasis and/or LMM than negative CXCL12 expression.ConclusionsEvaluation of CXCL12 and CXCR4 expression should assist detection of lymph node metastasis including LMM in submucosal ESCC. J. Surg. Oncol. 2008;97:433–438. © 2008 Wiley‐Liss, Inc.
Preparation and characterization of cellulose acetate‐coated compound fertilizer with controlled‐release and water‐retention
Authors: Wu Lan , Liu Mingzhu 
Published: January 2008

AbstractA novel cellulose acetate‐coated compound fertilizer with controlled‐release and water‐retention (CAFCW) was prepared, which possessed the three‐layer structure. Its core was water‐soluble compound fertilizer granular, the inner coating was cellulose acetate (CA), and the outer coating was poly(acrylic acid‐co‐acrylamide)/unexpanded vermiculite (P(AA‐co‐AM)/UVMT) superabsorbent composite. The effects of the amount of acrylamide, crosslinker, initiator, degree of neutralization of acrylic acid (AA), and unexpanded vermiculite concentration on water absorbency were investigated and optimized. The water absorbency of CAFCW was 72 times its own weight if it was allowed to swell in tap water at room temperature for 90 min. Element analysis and atomic absorption spectrophotometer results showed that the product contained 11% nitrogen, 6% phosphorus (shown by P2O5), 9% potassium (shown by K2O), 1% calcium (shown by CaO), and 0.4% magnesium (shown by MgO). Swelling rate, slow‐release, and water‐retention properties of CAFCW were also investigated. This product with good controlled‐release and water‐retention capacity, being degradable in soil and environmentally friendly, could be especially useful in agricultural and horticultural applications. Copyright © 2008 John Wiley & Sons, Ltd.
The Mycobacterium tuberculosis serine/threonine kinase PknL phosphorylates Rv2175c: Mass spectrometric profiling of the activation loop phosphorylation sites and their role in the recruitment of Rv2175c
Authors: Canova Marc J. , Veyron‐Churlet Romain , Zanella‐Cleon Isabelle , Cohen‐Gonsaud Martin , Cozzone Alain J. , Becchi Michel , Kremer Laurent , Molle Virginie 
Published: January 2008

AbstractAlthough Mycobacterium tuberculosis (M. tb) comprises 11 serine/threonine protein kinases, the mechanisms of regulation of these kinases and the nature of their endogenous substrates remain largely unknown. Herein, we characterized the M. tb kinase PknL by demonstrating that it expresses autophosphorylation activity and phosphorylates Rv2175c. On‐target dephosphorylation/MALDI‐TOF for identification of phosphorylated peptides was used in combination with LC‐ESI/MS/MS for localization of phosphorylation sites. By doing so, five phosphorylated threonine residues were identified in PknL. Among them, we showed that the activation loop phosphorylated residues Thr173 and Thr175 were essential for the autophosphorylation activity of PknL. Phosphorylation of the activation loop Thr173 residue is also required for optimal PknL‐mediated phosphorylation of Rv2175c. Together, our results indicate that phosphorylation of the PknL activation loop Thr residues not only controls PknL kinase activity but is also required for recruitment and phosphorylation of its substrate. Rv2175c was found to be phosphorylated when overexpressed and purified from Mycobacterium smegmatis as 2‐DE indicated the presence of different phosphorylated isoforms. Given the presence of the dcw gene cluster in the close vicinity of the pknL/Rv2175c locus, and its conservation in all mycobacterial species, we propose that PknL/Rv2175c may represent a functional pair in the regulation of mycobacterial cell division and cell envelope biosynthesis.
Proteomic analysis for inhibitory effect of chitosan oligosaccharides on 3T3‐L1 adipocyte differentiation
Authors: Rahman Md. Atiar , Kumar Suresh G. , Kim Sang Woo , Hwang Hye Jin , Baek Yu Mi , Lee Sung Hak , Hwang Hee Sun , Shon Yun Hee , Nam Kyung Soo , Yun Jong Won 
Published: January 2008

AbstractIn the present study, we performed a differential proteomic analysis using 2‐DE combined with MS to clarify the molecular mechanism for the suppressive effect of chitosan oligosaccharides (CO) during differentiation of adipocyte 3T3‐L1. Cell differentiation was significantly inhibited by CO at the concentration of 4 mg/mL. Protein mapping of adipocyte homogenates by 2‐DE revealed that numerous protein spots were differentially altered in response to CO treatment. Out of 50 identified proteins showing significant alterations, six were up‐regulated and 44 were down‐regulated by CO treatment in comparison to control mature adipocytes. Among them, most of the proteins are associated with lipid metabolism, cytoskeleton, and redox regulation, in which the levels of farnesyl diphosphate synthetase (FDS), dedicator of cytokinesis 9 (DOCK9), and chloride intracellular channel 1 (CLIC1) were significantly reduced (>two‐fold) with CO treatment. These results have not previously been examined in the context of adipogenesis, and thus can be used as novel biomarkers. Taken together with immunoblot analysis, it was concluded that the inhibitory effect of CO on adipocyte differentiation was mediated by C/EBPα and PPARγ pathway through significant downregulations of important adipogenic molecules such as fatty acid binding protein and glucose transporter 4.