bluuebunny/crossref_metadata_2025_split huggingface dataset:
Catalytic Properties of Nanoscale Iron‐Doped Zirconia Solid‐Solution Aerogels
Authors: Chen Lifang , Hu Juncheng , Richards Ryan M. 
Published: April 2008

AbstractNanoscale iron‐doped zirconia solid‐solution aerogels are prepared via a simple ethanol thermal route using zirconyl nitrate and iron nitrate as starting materials, followed by a supercritical fluid drying process. Structural characteristics are investigated by means of powder X‐ray diffraction (XRD), thermal analyses (TG/DTA), N2 adsorption measurements and diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The results show that the resulting iron‐doped solid solutions are metastable tetragonal zirconia which exhibit excellent dispersibility and high solubility of iron oxide. Further, when the Fe:(Fe+Zr) ratio x is lower than 0.10, all of the Fe3+ ions can be incorporated into ZrO2 by substituting Zr4+ to form Zr1−xFexOy solid solutions. Moreover, for the first time, an additional hydroxyl group band that is not present in pure ZrO2 is observed by DRIFTS for the Zr(Fe)O2 solid solution. This is direct evidence of Fe3+ ions incorporated into ZrO2. These Zr1−xFexOy solid solutions are excellent catalysts for the solvent‐free aerobic oxidation of n‐hexadecane using air as the oxidant under ambient conditions. The Zr0.8Fe0.2Oy solid‐solution catalyst demonstrates the best catalytic properties, with the conversion of n‐hexadecane reaching 36.2 % with 48 % selectivity for ketones and 24 % selectivity for alcohols and it can be recycled five times without significant loss of activity.
Preventive Care in African American Women with End‐Stage Renal Disease
Authors: Goyal Vinita , Levison Sandra , Bavendam Tamara , Gillen Daniel , Stehman‐Breen Catherine 
Published: April 2008

AbstractBACKGROUNDRoutine cancer screening may be of particular importance to women with renal failure, who are at greater risk for cervical, uterine, and colorectal cancer. Most dialysis patients rely on their nephrologists for preventive care. However, this care may not be similar to that provided by primary care physicians. We compared the prevalence of cancer screening between women with and without end‐stage renal disease.METHODSForty‐six women on dialysis were compared with 25 women attending an ambulatory care resident clinic and 25 women attending a specialty women's clinic at the same institution. A verbal questionnaire was used to determine if these women received appropriate screening for cervical, breast, and colorectal cancer.RESULTSWomen without end‐stage renal disease were more likely to receive breast cancer screening (aOR = 5.94, 95% CI: 1.87, 18.9) routine cervical cancer screening (aOR = 4.57, 95% CI: 1.60, 13.1), and colorectal cancer screening (aOR = 2.73, 95% CI: 0.89, 8.39) when compared with women with renal failure . A higher percentage of women on dialysis reported never receiving a recommendation from a physician to obtain cervical or breast cancer screening.CONCLUSIONSAfrican American women on dialysis received less preventive care than did women without end‐stage renal disease. Examination of factors influencing preventive screening among dialysis patients is warranted.
Prevention of Sudden Cardiac Death in Dialysis Patients: A Nephrologist's Perspective
Authors: Bleyer Anthony J. 
Published: April 2008

AbstractSudden death is a common and at times preventable cause of death in the dialysis population. Prevention of sudden death can be accomplished in the dialysis population by proper management of cardiac disease and attention to dialysis treatment. The proper usage of medications such as angiotensin‐converting enzyme inhibitors and beta‐blockers is likely to decrease the risk of sudden death, yet these medications are underutilized in the dialysis population. Appropriate management of dialysate potassium is also important. A systematic method should be developed in each dialysis center to identify risk factors for sudden death, institute appropriate treatment, and monitor outcomes.
The cholinergic gene locus in amphioxus: Molecular characterization and developmental expression patterns
Authors: Candiani Simona , Lacalli Thurston C. , Parodi Manuela , Oliveri Diana , Pestarino Mario 
Published: April 2008

AbstractThe cholinergic gene locus (CGL), consisting of the vesicular acetylcholine transporter (VAChT)/choline acetyltransferase (ChAT) gene, encodes two specific cholinergic neuronal markers used extensively to study cholinergic transmission. In the present work, we isolated the amphioxus homologs of VAChT and ChAT and examined their expression during development. Analysis of the 5′ untranslated region of VAChT and ChAT suggests that the splicing of the VAChT/ChAT mRNA has been evolutionarily conserved in amphioxus and mammals. By double whole‐mount in situ hybridization, we demonstrate that VAChT and ChAT are coexpressed in the same cells. They are first expressed in four pairs of differentiating cells in the neural plate. Their later expression is primarily in the anterior nerve cord in several types of motoneurons, some of the interneurons and in the receptor cells of the larval ocellus. Developmental Dynamics 237:1399‐1411, 2008. © 2008 Wiley‐Liss, Inc.
Mixed‐Ligand Oxidovanadium(V) Complexes with N′‐Salicylidenehydrazides: Synthesis, Structure, and 51V Solid‐State MAS NMR Investigation
Authors: Nica Simona , Buchholz Axel , Rudolph Manfred , Schweitzer Annika , Wächtler Maria , Breitzke Hergen , Buntkowsky Gerd , Plass Winfried 
Published: April 2008

AbstractThe synthesis and spectroscopic characterization of a series of three oxidovanadium(V) complexes with 8‐hydroxyquinoline and Schiff‐base ligands derived from salicylaldehyde and ω‐hydroxy‐functionalized carbohydrazides with different chain lengths are reported. The complex with the hydrazone ligand containing the shortest chain length was crystallographically characterized. This complex crystallizes in the triclinic space group P$\bar {1}$ with two structurally similar but crystallographically independent oxidovanadium(V) complexes. Each vanadium atom is six‐coordinate in a distorted‐octahedral geometry. The two molecules are assembled through hydrogen‐bonding interactions between the hydroxyl groups of the side‐chain substituted Schiff‐base ligand and the oxido group of one of the two complexes. Electrochemical measurements performed in acetonitrile solution reveal two reversible one‐electron reduction steps. The observed pre‐wave feature of the second reduction step indicates the presence of dissociation equilibria related to the 8‐hydroxyquinoline coligand. Magic‐angle spinning solid‐state 51V NMR spectroscopy allowed to characterize the full series of complexes with alkyl and hydroxy alkyl‐substituted hydrazone ligands that were used. The quadrupolar coupling constants are small with a value of about 4 MHz and show little variation within the series. The asymmetry of the chemical shift tensor indicates a rather axial symmetric environment around the vanadium(V) center. The isotropic chemical shifts observed in the solid state occur at about 30 ppm, which is in the same order of magnitude as the solvent induced variations, about 10 ppm, found for different solvents.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Sequential Metal‐Catalyzed N‐Heteroarylation and C–C Cross‐Coupling Reactions: An Expedient Route to Tris(hetero)aryl Systems
Authors: Siddle Jamie S. , Batsanov Andrei S. , Bryce Martin R. 
Published: April 2008

AbstractThis paper describes copper‐catalyzed N–C heteroarylation of benzimidazole, 1‐methylbenzimidazolone, imidazole and pyrrole. The products of these reactions then undergo palladium‐catalyzed C–C cross‐couplings with aryl or heteroarylboronic acids under Suzuki–Miyaura conditions to provide a rapid entry, from readily‐available reagents, into tris(hetero)aryl scaffolds comprising two or three N‐heterocyclic rings. The sequential N–C and C–C couplings can be performed in a one‐pot process (two examples are given: >50 % overall yields). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
The phenomenology of minority–majority status: Effects on innovation in argument generation
Authors: Kenworthy Jared B. , Hewstone Miles , Levine John M. , Martin Robin , Willis Hazel 
Published: April 2008

AbstractIn three experiments, we manipulated participants' perceived numerical status and compared the originality and creativity of arguments generated by members of numerical minorities and majorities. Independent judges, blind to experimental conditions, rated participants' written arguments. In Studies 1 and 2, we found that participants assigned to a numerical minority generated more original arguments when advocating their own position than did numerical majorities. In Study 3, an equal‐factions control group was included in the design, and all participants were instructed to argue for a counter‐attitudinal position. Those in the numerical minority generated more creative arguments than those in both the majority and equal‐factions conditions, but not stronger arguments. We propose cognitive and social processes that may underlie our obtained effects and discuss implications for minority influence research. Copyright © 2008 John Wiley & Sons, Ltd.
Electrical field‐assisted solid‐phase extraction coupled on‐line to capillary electrophoresis‐mass spectrometry
Authors: Morales‐Cid Gabriel , Simonet Bartolomé M. , Cárdenas Soledad , Valcárcel Miguel 
Published: April 2008

AbstractA substantial demand currently exists for analytical methods affording the determination of very low concentrations of analytes in complex matrices, such as those of environmental and biological samples, as simply as possible. However, the pretreatment of complex samples, which is unavoidable prior to CE‐MS analysis, is usually complicated and time‐consuming. In this work, we used voltage‐assisted SPE for the first time as an alternative to conventional treatments for preconcentrating and purifying analytes. To this end, we used a simple flow system coupled on‐line to CE‐MS equipment. The system is quite robust and provides reproducible peak areas (the precision ranges from 2.5 to 3.8%). Also, it provides increased sensitivity affording the determination of trace amounts (nanogram per liter levels) of analytes in only a few milliliters of sample. The proposed system was applied to the determination of members of two compound families (viz. tetracyclines and amines).
Analyses of gibberellins in coconut (Cocos nucifera L.) water by partial filling‐micellar electrokinetic chromatography‐mass spectrometry with reversal of electroosmotic flow
Authors: Ge Liya , Yong Jean Wan Hong , Tan Swee Ngin , Hua Lin , Ong Eng Shi 
Published: April 2008

AbstractIn this paper, we present the results of simultaneous screening of eight gibberellins (GAs) in coconut (Cocos nucifera L.) water by MEKC directly coupled to ESI‐MS detection. During the development of MEKC‐MS, partial filling (PF) was used to prevent the micelles from reaching the mass spectrometer as this is detrimental to the MS signal, and a cationic surfactant, cetyltrimethylammonium hydroxide, was added to the electrolyte to reverse the EOF. On the basis of the resolution of the neighboring peaks, different parameters (i.e., the pH and concentration of buffer, surfactant concentrations, length of the injected micellar plug, organic modifier, and applied separation voltage) were optimized to achieve a satisfactory PF‐MEKC separation of eight GA standards. Under optimum conditions, a baseline separation of GA standards, including GA1, GA3, GA5, GA6, GA7, GA9, GA12, and GA13, was accomplished within 25 min. Satisfactory results were obtained in terms of precision (RSD of migration time below 0.9%), sensitivity (LODs in the range of 0.8–1.9 μM) and linearity (R2 between 0.981 and 0.997). MS/MS with multiple reaction monitoring (MRM) detection was carried out to obtain sufficient selectivity. PF‐MEKC‐MS/MS allowed the direct identification and confirmation of the GAs presented in coconut water (CW) sample after SPE, while, the quantitative analysis of GAs was performed by PF‐MEKC‐MS approach. GA1 and GA3 were successfully detected and quantified in CW. It is anticipated that the current PF‐MEKC‐MS method can be applicable to analyze GAs in a wide range of biological samples.
Constant pressure‐assisted electrokinetic injection for on‐line enhanced detection of monophthalates in capillary electrophoresis‐mass spectrometry with application to human urine
Authors: Feng Yong‐Lai , Zhu Jiping 
Published: April 2008

AbstractElectrophoresis characteristics of several monophthalates in the sample zone and EOF variation in a fused‐silica capillary column during a constant pressure‐assisted electrokinetic injection (PAEKI) in an on‐line CE‐MS were studied in an effort to reconcile the mobility theory and field amplification with the enhancement achieved in present work. Influences of capillary length on the amount injected using PAEKI were investigated in detail and except for the injection time, the amount injected was found to increase linearly with capillary column length. A longer capillary provides a longer linear increase time range with PAEKI injection. The results show that smaller m/z analytes generate a large enhancement power using PAEKI, which is in agreement with the mobility theory. ACN was used as an example to investigate influences of organic additives on the amount injected and was found to decrease the amount injected with PAEKI injection, which is in agreement with an increase of resistivity in running buffer by organic additives. The peak width obtained with PAEKI injection proved to be independent of the amount injected. The band size of the sample zone was estimated by comparison with conventional hydrodynamic injection. A 240 s PAEKI injection achieved the same size of sample zone as a 2 s of hydrodynamic injection. Existance of two ion layers around the boundary of the buffer and sample solutions in sample zone was hypothesized to contribute the narrow sample zone with a long time of PAEKI injection. With a 240 s on‐line PAEKI injection in CZE‐MS, five monophthalates were enriched several hundred times without compromise in their separation efficiency and peak shape. With appropriate sample cleanup, PAEKI was applied to the analysis of monophthalates in urine samples, achieving detection limits ranging between 0.53 and 1.3 ng/mL.
Biodegradation of Methyl Ethyl Ketone and Methyl Isopropyl Ketone in a Composite Bead Biofilter
Authors: Chan W.‐C. , Peng K.‐H. 
Published: April 2008

AbstractBiodegradation of methyl ethyl ketone (MEK) and methyl isopropyl ketone (MIPK) in a composite bead biofilter was investigated. The composite bead represents a spherical PVA/peat/KNO3/GAC one. Both the microbial growth rate μ and the biochemical reaction rate coefficient kd could be affected with increasing inlet concentration. For the microbial growth process, an inhibitory effect of almost the same sensitivity for the two ketone compounds and the μ value of MEK was more pronounced than that of MIPK in the inlet concentration range of 100 to 300 ppm. The half‐saturation constant Ks values of MEK and MIPK were 21.56 and 22.96 ppm, respectively. The maximum reaction rate Vm values of MEK and MIPK were 9.06 and 7.55 g C/h kg of packed material, respectively. Zero‐order kinetics with diffusion limitation could be regarded as the most adequate biochemical reaction model. For the biochemical process, the inhibitory effect for MEK was more notable than that for MIPK in the inlet concentration range of 100 to 150 ppm whereas it was the reverse in the inlet concentration range of 150 to 300 ppm. The kd value of MEK was greater than that of MIPK in the inlet concentration range of 100 to 300 ppm. The maximum elimination capacities of MEK and MIPK were found to be 44.2 and 35.2 g C/h m3 of bed volume. MEK, in particular the compound with a lower number of carbons or no side groups in the main chain, was easier biodegraded by the microorganisms than MIPK.
Applications of PAT‐Process Analytical Technology in Recombinant Protein Processes with Escherichia coli
Authors: Kaiser C. , Pototzki T. , Ellert A. , Luttmann R. 
Published: April 2008

AbstractMonitoring of bioprocesses and thus observation and identification of such processes is one of the main aims of bioprocess engineering. It is of vital importance in bioprocess development to improve the overall productivity by avoiding unintentional limitations to ensure not only optimal process conditions but also the observation of established production processes. Furthermore, reproducibility needs to be improved and final product quality and quantity be guaranteed. Therefore, an advanced monitoring and control system has been developed, which is based on different in‐line, on‐line and at‐line measurements for substrates and products. Observation of cell viability applying in‐line radio frequency impedance measurement and on‐line determination of intracellular recombinant target protein using the reporter protein T‐Sapphire GFP based on in‐line fluorescence measurement show the ability for the detection of critical process states. In this way, the possibility for the on‐line recognition of optimal harvest times arises and disturbances in the scheduled process route can be perceived.
Maximum kurtosis estimation of the optimal filter and convergence step size parameter in blind adaptive TEQ for multicarrier systems
Authors: Bellahsene H. , Rouvaen J. M. , Djeddi M. 
Published: April 2008

AbstractThe effective channel channel shortening equalisers (CSE) using blind adaptive algorithms have run into great interest. These are very important for orthogonal sub‐carrier maintained for multicarrier modulation (MCM) and reduce consequently the complexity of multi‐users detection algorithms. We review in this paper the evolution from classical equalisation to the channel shortening equalisation. We utilise the calculus of maximum kurtosis for determining the optimal time domain equaliser (TEQ) and synchronisation delay for the maximum shortening signal to noise ratio (MSSNR) algorithm. We compare the optimal filters obtained by other methods and the proposed method based on maximum kurtosis. Copyright © 2008 John Wiley & Sons, Ltd.
Chemical variability of the leaf oil of 113 hybrids from Citrus clementina (Commun) × Citrus deliciosa (Willow Leaf)
Authors: Tomi Félix , Barzalona Marina , Casanova Joseph , Luro François 
Published: April 2008

AbstractEssential oils of 113 Citrus clementina (Commun) × Citrus deliciosa (Willow Leaf) hybrids were obtained from leaves collected on trees located in the same orchard. Their chemical composition was investigated by capillary GC, GC–MS and 13C‐NMR and the results were submitted to statistical analysis. Three chemical compositions were characterized. The crossing between clementine and mandarin produces mainly leaf oils characterized by a composition similar to those of the parents (sabinene/linalool or methyl N‐methylanthranylate). However, several samples exhibited an original composition (γ‐terpinene/linalool). Copyright © 2008 John Wiley & Sons, Ltd.
New chitinozoans from the historical type area of the Hirnantian Stage and additional key sections in the Wye Valley, Wales, UK
Authors: Vandenbroucke Thijs R. A. , Hennissen Jan , Zalasiewicz Jan A. , Verniers Jacques 
Published: April 2008

AbstractThe type locality for several core elements of the Hirnantia brachiopod fauna is a small disused quarry on the western slopes of Cwm Hirnant. There, the Hirnant Limestone Member of the Foel‐y‐Ddinas Mudstone Formation yields a new, well‐preserved chitinozoan assemblage, attributed to the Spinachitina taugourdeaui Biozone. This allows tight correlation with the Hirnantian of Baltica and Laurentia and neatly ties the chitinozoan zonation with the classical brachiopod fauna. Nearby, the chitinozoan assemblage from the Caradoc Cymerig Limestone Member at Gelli‐grîn belongs to the Spinachitina cervicornis Biozone?, and is identical to that recovered from the Burrellian in the Onny Valley, Welsh Borderland. A Silurian assemblage higher up section, discovered in the Cwm‐yr‐Aethnen Formation, is attributed to the globally recognized Eisenackitina dolioliformis Biozone. Attempts to integrate the chitinozoan and graptolite biozonation, in the central Welsh Rhayader area, were less successful. Copyright © 2008 John Wiley & Sons, Ltd.
Estrogen‐mediated downregulation of CD24 in breast cancer cells
Authors: Kaipparettu Benny Abraham , Malik Simeen , Konduri Santhi D. , Liu Wensheng , Rokavec Matjaž , van der Kuip Heiko , Hoppe Reiner , Hammerich‐Hille Stephanie , Fritz Peter , Schroth Werner , Abele Ina , Das Gokul M. , Oesterreich Steffi , Brauch Hiltrud 
Published: April 2008

AbstractWe have previously reported on the relevance of the prevalence of CD44+/CD24−/low cells in primary breast tumors. To study regulation of CD24, we queried a number of publicly available expression array studies in breast cancer cells and found that CD24 was downregulated upon estrogen treatment. We confirmed this estrogen‐mediated repression of CD24 mRNA by quantitative real‐time PCR in MCF7, T47D and ZR75‐1 cells. Repression was also seen at the protein level as measured by flow cytometry. CD24 was not downregulated in the ERα negative MDA‐MB‐231 cells suggesting that ERα was necessary. This was further confirmed by ERα silencing in MCF7 cells resulting in increased CD24 levels and by reintroduction of ERα into C4‐12 cells resulting in decreased CD24 levels. Estrogen treatment did not alter half‐life of CD24 mRNA and new protein synthesis was not essential for repression, suggesting a primary transcriptional effect. Histone deacetylase inhibition by Trichostatin A completely abolished the repression, but decrease of the ERα corepressors NCoR, LCoR, RIP140, silencing mediator of retinoid and thyroid hormone receptors, SAFB1 and SAFB2 by siRNA or overexpression of SAFB2, NCoR and silencing mediator of retinoid and thyroid hormone receptors had no effect. In silico promoter analyses led to the identification of two estrogen responsive elements in the CD24 promoter, one of which was able to bind ERα as shown by electrophoretic mobility shift assay and chromatin immunoprecipitation assay. Together, our results show that CD24 is repressed by estrogen and that this repression is a direct transcriptional effect depending on ERα and histone deacetylases. © 2008 Wiley‐Liss, Inc.
Supramolecular hydrogels based on self‐assembly between PEO‐PPO‐PEO triblock copolymers and α‐cyclodextrin
Authors: Ni Xiping , Cheng Alan , Li Jun 
Published: April 2008

AbstractThis article reports a detailed study on the hydrogel formation of poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO‐PPO‐PEO) triblock copolymers with α‐cyclodextrin (α‐CD) in aqueous solutions. The gelation kinetics and the gel rheological properties were studied using viscometry. The sol–gel phase transitions were studied using phase diagrams, while the gelation mechanism was studied using differential scanning calorimetric analysis. It was concluded that the gelation was induced by the complex formation between the PEO segments of the PEO‐PPO‐PEO triblock copolymer and α‐CD, and the further self‐assembly of the partially formed inclusion complexes. The addition of α‐CD largely reduced the concentration of the copolymer needed for gel formation. The gels were thixotropic and reversible, and potentially suitable for use as an injectable drug‐delivery system. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009