bluuebunny/crossref_metadata_2025_split huggingface dataset:
The performance analyses of multitarget CMA adaptive array considering mutual coupling and diffraction effects
Authors: Xu Jin , Zhu GuoQiang , Yuan Fei 
Published: November 2006

AbstractThe performance of a multitarget constant modulus algorithm (MU‐CMA) adaptive array located on a regular conducting plate is studied in this paper. The effects of mutual coupling (MC) between array elements and diffraction caused by the conducting plate are taken into account. A hybrid method of equivalent edge current method (ECM) and moment method (MM) is employed in electromagnetic calculation to investigate the distortion of initial array pattern. We compare the capture property of three well‐known MU‐CMA arrays, respectively: multitarget least‐squares constant modulus array (MT‐LSCMA), multitarget decision‐directed array (MT‐DD) and least‐squares despread respread multitarget constant modulus array (LS‐DRMTCMA). Simulation result shows that: (i) the distorted initial pattern leads to the descending of the signal catch performance of MT‐LSCMA and MT‐DD; (ii) only the LS‐DRMTCMA can work correctly due to its stronger anti‐jamming ability in the presence of MC and diffraction. Copyright © 2006 John Wiley & Sons, Ltd.
Critical Loads for Cd and Pb in the Province of Bologna
Authors: Morselli Luciano , Bernardi Elena , Passarini Fabrizio , Tesini Enrico 
Published: November 2006

AbstractAtmospheric deposition represents a significant source of heavy metals entering soil and aquatic ecosystems. The evaluation of their vulnerability can be carried out by the Critical Load criterion. In this work we focus the attention on the terrestrial ecosystems in the Province of Bologna, estimating the maximum tolerable load of cadmium and lead they are able to bear without sustain the occurrence of harmful ecotoxicological effects. To this aim the Steady‐State Mass Balance method is applied on a small scale (10×10 Km EMEP grids) and the more suitable approach to define critical limits for the Province condition, effect‐base or stand‐still, is discussed. The opportunity of simplifying the input data collection is also considered, trying to deduce soil properties from geological information.Finally, the environmental risk due to the present deposition of Pb and Cd on provincial soils is described as exceedances over the critical loads.
Reactions in Droplets in Microfluidic Channels
Authors: Song Helen , Chen Delai L. , Ismagilov Rustem F. 
Published: November 2006

AbstractFundamental and applied research in chemistry and biology benefits from opportunities provided by droplet‐based microfluidic systems. These systems enable the miniaturization of reactions by compartmentalizing reactions in droplets of femoliter to microliter volumes. Compartmentalization in droplets provides rapid mixing of reagents, control of the timing of reactions on timescales from milliseconds to months, control of interfacial properties, and the ability to synthesize and transport solid reagents and products. Droplet‐based microfluidics can help to enhance and accelerate chemical and biochemical screening, protein crystallization, enzymatic kinetics, and assays. Moreover, the control provided by droplets in microfluidic devices can lead to new scientific methods and insights.
Chemiluminescence of synephrine based on the cerium(IV)–rhodamine B system
Authors: Wang Ruifen , Wan Lijuan , Li Qian , Liu Xidong , Huang Yuming 
Published: November 2006

AbstractA new chemiluminescence (CL) method is described for the determination of synephrine. It is based on the reaction between synephrine and Ce(IV) in a nitric acid medium and measurement of the CL intensity produced by rhodamine B used as a luminophore, similar to luminol or lucigenin in basic media, instead of as a sensitizer. In the optimum conditions, the increase of CL intensity was correlated with synephrine concentration over the range 5.0 × 10−9–1.0 × 10−6 g/mL with a detection limit of 1.0 × 10−9 g/mL. The relative standard deviation (RSD) was 2.9% for 1.0 × 10−7 g/mL synephrine (n = 11). The method was applied to the determination of a drug in herbal products, citrus fruit and biological samples, with satisfactory results. The results given by the proposed method are in good agreement with those given by HPLC‐UV and UV spectrophotometry. Copyright © 2006 John Wiley & Sons, Ltd.
Development of imidazopyrazinone red‐chemiluminescent probes for detecting superoxide anions via a chemiluminescence resonance energy transfer method
Authors: Teranishi Katsunori 
Published: November 2006

AbstractDuring the development of useful probes for detecting superoxide anions via chemiluminescence with longer wavelengths than that of green, chemiluminescent probes that emit red light (λmax 610 nm) when induced by superoxide anions were synthesized and characterized. These red‐chemiluminescent probes consist of a 6‐(4‐methoxyphenyl)imidazo[1,2‐a] pyrazin‐3(7H)‐one moiety, which reacts with superoxide anions to generate energy, and a sulphorhodamine 101 moiety, which accepts the energy and emits red light. Using a hypoxanthine–xanthine oxidase system for the generation of superoxide anions, it was shown that the superoxide anion‐induced chemiluminescences of red‐chemiluminescent probes (3 and 4) were more intense than those of the blue‐ and green‐chemiluminescent probes 2‐methyl‐6‐(4‐methoxyphenyl)imidazo[1,2‐a] pyrazin‐3(7H)‐one (MCLA) and 6‐[4‐[2‐[N′‐(5‐fluoresceinyl)thioureido]‐ethoxy]phenyl]‐2‐methylimidazo[1,2‐a]pyrazin‐3(7H)‐one (FCLA), respectively, which are generally considered to be the most sensitive chemiluminescent probes. The ratio between the superoxide‐dependent and background chemiluminescence intensities for 3 was comparable to those of MCLA and FCLA, but higher than that of 4. Due to its highly intense superoxide anion‐induced chemiluminescence at low probe concentrations, red‐chemiluminescent probe 3 is superior to MCLA and FCLA for measurement of superoxide anions. Copyright © 2006 John Wiley & Sons, Ltd.
Rapid formation of hydrogen‐producing granules in an anaerobic continuous stirred tank reactor induced by acid incubation
Authors: Zhang Zhen‐Peng , Show Kuan‐Yeow , Tay Joo‐Hwa , Liang David Tee , Lee Duu‐Jong , Jiang Wen‐Ju 
Published: November 2006

AbstractA novel approach to rapidly initiate granulation of hydrogen‐producing sludge was developed in an anaerobic continuous stirred tank reactor at 37°C. To induce microbial granulation, the acclimated culture was subject to an acid incubation for 24 h by shifting the culture pH from 5.5 to 2.0. The culture was resumed to pH 5.5 after the incubation and the reactor was operated at hydraulic retention times (HRTs) of 12, 6, 2, 1, and 0.5 h in sequence. Microbial aggregation took place immediately with the initiation of acid incubation and granules were developed at 114 h. No granule was observed in the absence of acid incubation in the control test. Changing the culture pH resulted in improvement in surface physicochemical properties of the culture favoring microbial granulation. The zeta potential increased from −11.6 to −3.5 mV, hydrophobicity in terms of contact angle improved from 31° to 43° and extracellular proteins/polysaccharides ratio increased from 0.2 to 0.5–0.8. Formation of granular sludge facilitated biomass retention of up to 32.2 g‐VSS/L and enhanced hydrogen production. The hydrogen production rate and hydrogen yield increased with the reduction in HRT at an influent glucose concentration of 10 g/L once steady granular sludge layer was formed, achieving the respective peaks of 3.20 L/L · h and 1.81 mol‐H2/mol‐glucose at 0.5 h HRT. The experimental results suggested that acid incubation was able to initiate the rapid formation of hydrogen‐producing granules by regulating the surface characteristics of microbial aggregates in a well‐mixed reactor, which enhanced the hydrogen production. Biotechnol. Bioeng. 2007;96:1040–1050. © 2006 Wiley Periodicals, Inc.
An in silico model for HIF‐α regulation and hypoxia response in tumor cells
Authors: Yucel Meryem A. , Kurnaz Isil Aksan 
Published: November 2006

AbstractThe dependency of the growth and metastasis of tumors on the new blood vessel formation, or angiogenesis, has opened up new potentials to tumor therapy, nevertheless understanding the molecular mechanisms involved in angiogenesis is crucial in the bioengineering of novel anti‐angiogenic drugs. The key component in hypoxia sensing in tumor cells is the hypoxia‐inducible factor, HIF‐1α, which is inactivated through proteosome‐mediated degradation under normoxic conditions. Two enzymes have been reported to hydroxylate HIF‐1α, namely prolyl hydroxylase (PH), recruiting the proetasome complex and degrading cytoplasmic HIF‐1α, and asparaginyl hydroxylase/factor inhibiting HIF‐1α (FIH‐1), downregulating the recruitment of p300 to the promoter, thereby reducing the transcriptional activity of HIF‐1α. In this study, we have constructed an in silico model of a tumor cell using the GEPASI 3.30 biochemical simulation software (http://www.gepasi.org) and studied the performances of PH and FIH‐1 on HIF‐1α degradation and inactivation, respectively, as monitored by expression of the vascular endothelial growth factor, VEGF, during hypoxia. In our biochemical models, FIH‐1 can successfully increase hypoxic transcription of VEGF, however FIH‐1 on its own is not sufficient to inactivate HIF‐1 completely, leading to background VEGF transcription under normoxic conditions. On the other hand, PH is necessary to increase the hypoxic transcriptional response, and can effectively shut off normoxic transcription. We therefore propose that regulating PH activity can be a primary target for anti‐angiogenic bioengineering research. Biotechnol. Bioeng. 2007;97: 588–600. © 2006 Wiley Periodicals, Inc.
Characterization of Peptide–Pyrazole Interactions in Solution by Low‐Temperature NMR Studies
Authors: Wang Wei , Weisz Klaus 
Published: November 2006

AbstractComplexation of the amino‐ and carboxyl‐protected tripeptide Piv‐L‐Val‐L‐Val‐L‐Val‐tBu with 3‐methylpyrazole and 3‐amino‐5‐methylpyrazole was studied by low‐temperature NMR experiments in a freonic solvent. The peptide forms an extended β‐type structure at all temperatures and associates through hydrogen bonding with the two pyrazole‐based β‐sheet ligands. A detailed structural characterization of the formed complexes by one‐ and two‐dimensional NMR experiments under slow exchange conditions was made possible by employing very low temperatures. The tripeptide associates to stable antiparallel dimers that are symmetrically capped on both sides by two pyrazole receptors to form 2:2 complexes. Amide groups of two neighboring residues in an extended conformation are involved in cyclic hydrogen bonds to the pyrazole. Based on amide chemical shift changes, the relative strength of intermolecular hydrogen bonds can be assessed and correlated with the electronic effects of the substituents on the pyrazole.
Reactions of Sn(NMe2)2 with MPHCy: The Effects of Alkali Metal Phosphide Coupling (Cy=Cyclohexyl; M=Li, Na, K, Rb)
Authors: Alvarez Paula , García Felipe , Hehn Jörg P. , Kraus Florian , Lawson Gavin T. , Korber Nikolaus , Mosquera Marta E. G. , McPartlin Mary , Moncrieff David , Pask Christopher M. , Woods Anthony D. , Wright Dominic S. 
Published: November 2006

AbstractThe reactions of the SnII base Sn(NMe2)2 with CyPHM (Cy=cyclohexyl) produce a range of products, depending primarily on the alkali metal (M) involved. The 1:3 stoichiometric reaction of Sn(NMe2)2 with CyPHNa in the presence of the Lewis base donor PMDETA (PMDETA=(Me2NCH2CH2)2NMe) gives [(Na⋅PMDETA)2{Sn(μ‐PCy)}3] (3), containing the electron‐deficient [{Sn(μ‐PCy)}3]2− dianion. Natural bond order (NBO) and electron localisation function (ELF) calculations show that this species is described most appropriately by a two‐electron, three‐centre Sn3 bonding model. Evidence that 3 results from phosphide coupling is provided by the 1:1 reaction of Sn(NMe2)2 with CyPHNa in the presence of PMDETA, which gives 3 and trace amounts of (Na⋅PMDETA)2[{Sn(μ‐PCy)}2(μ‐PCyPCy)] (4) (containing one PCyPCy2− dianion). Greater extents of phosphide coupling are observed as the size of the Group 1 metal is increased. Thus, the 1:3 reaction of Sn(NMe2)2 with CyPHK in THF gives the co‐crystalline product {(K⋅2 THF)2[{Sn(μ‐PCyPCy)}2(μ‐PCy)]}0.9{(K⋅2 THF)2[{Sn(μ‐PCy)}2(μ‐PCyPCy)]}0.1 (5) (containing [{Sn(μ‐PCyPCy)}2(μ‐PCy)]2− and [{Sn(μ‐PCy)}2(μ‐PCyPCy)]2− dianions), whereas the analogous reaction of Sn(NMe2)2 with RbPHCy gives [Rb⋅PMDETA{(CyP)3SnP(H)Cy}] (6) (containing a cyclic {(CyP)3Sn} unit).
The Effect of Counterion/Ligand Interplay on the Activity and Stereoselectivity of Palladium(II)–Diimine Catalysts for CO/p‐Methylstyrene Copolymerization
Authors: Binotti Barbara , Bellachioma Gianfranco , Cardaci Giuseppe , Carfagna Carla , Zuccaccia Cristiano , Macchioni Alceo 
Published: November 2006

AbstractThe catalytic activity and stereoselectivity of complexes [Pd(η1,η2‐C8H12OMe)(ArNC(R′)C(R′)NAr)]X in the copolymerization of CO and p‐methylstyrene have been correlated with their interionic structure in solution and in the solid state, as determined by 19F,1H‐HOESY NMR spectroscopy and X‐ray diffraction studies, respectively. The highest productivity is obtained with unhindered diimine ligands bearing electron‐donating substituents and with the least coordinating counterion. Copolymers with a microstructure ranging from atactic to predominantly isotactic are obtained. The degree of isotacticity increases as the steric hindrance in the apical positions and the coordinating ability of the counterion increase. The counterion is located close to the diimine in both solution and the solid state but it moves toward the palladium as the steric hindrance in the apical positions decreases. When the latter is small the counterion competes with the substrate for apical coordination, and consequently it affects the productivity. In the case of ortho‐dimethyl‐substituted ligands the counterion is confined in the back, above the NC(R′)C(R′)N moiety, and does not affect the productivity. However, it contributes to increasing the stereoregularity of the copolymer by making the aryl moieties more rigid. With R′=Me and Ar=o‐Me2C6H3 an ll of 81 % and 72 % was obtained with X−=CF3SO3− or BArF−, respectively. The isotacticity of the copolymers produced by ortho‐monosubstituted catalysts depends greatly on the counterion and ranges from 30 % to 59 % with X−=BArF− and X−=CF3SO3−, respectively, with Ar=o‐EtC6H4 and R′=Me. Based on the interionic structural results, this effect can be explained by a greater reduction of the copolymerization rate of Cs‐symmetric isomers with respect to their C2‐symmetric counterparts.
The stereoselective metabolism of halofantrine to desbutylhalofantrine in the rat: Evidence of tissue‐specific enantioselectivity in microsomal metabolism
Authors: Gharavi Negar , Sattari Somayeh , Shayeganpour Anooshirvan , El‐Kadi Ayman O.S. , Brocks Dion R. 
Published: November 2006

AbstractThe pharmacokinetics of the antimalarial drug (±)‐halofantrine are stereoselective in humans and rats. To better understand the stereoselective metabolism of the drug to its primary metabolite, desbutylhalofantrine (DHF), a series of in vitro and in vivo experiments were undertaken in the rat. Formation of (−)‐DHF exceeded that of (+)‐DHF in liver microsomes [(−):(+) ratio of intrinsic formation clearances = 1.4]. In contrast, in intestinal microsomes no significant stereoselectivity was noted in the formation of the DHF enantiomers. Intestinal microsomes were also less efficient at producing the DHF enantiomers than were liver microsomes. Based on kinetic analysis of the DHF formation, there appeared to be more than one enzyme involved in the biotransformation. (±)‐Ketoconazole (KTZ) effectively inhibited the formation of both DHF enantiomers by both liver and intestinal microsomes, although the reduction was more marked in liver microsomes. Through a combination of the use of CYP antibodies and recombinant CYP isoenzymes, the involvement of CYP 2B1/2, 3A1, 3A2, 1A1, 2C11, 2C6, 2D1, and 2D2 were implicated in the metabolism of halofantrine to DHF. Of these, CYP3A1/2 and CYP2C11 appeared to be the primary isoenzymes involved, although CYP2C11 showed greater (+)‐DHF than (−)‐DHF formation, whereas for CYP3A1 it was similar to the isolated rat liver microsomes. In vivo, oral (±)‐KTZ caused significant increases in plasma halofantrine and decreases in DHF enantiomer plasma concentrations. Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Stereoselective determination of benalaxyl in plasma by chiral high‐performance liquid chromatography with diode array detector and application to pharmacokinetic study in rabbits
Authors: Qiu Jing , Wang Qiuxia , Zhu Wentao , Jia Guifang , Wang Xinquan , Zhou Zhiqiang 
Published: November 2006

AbstractA chiral high‐performance liquid chromatography method with diode array detector was developed and validated for stereoselective determination of benalaxyl (BX) in rabbit plasma. Good separation was achieved at 20°C using cellulose tris‐(3,5‐dimethylphenylcarbamate) as chiral stationary phase, a mixture of n‐hexane and 2‐propanol (97:3) as mobile phase at a flow rate of 1.0 ml/min. The assay method was linear over a range of concentrations (0.25–25 μg/ml) in plasma and the mean recovery was greater than 90% for both enantiomers. The limits of quantification and detection for both enantiomers in plasma were 0.25 and 0.1 μg/ml, respectively. Intra‐ and interday relative standard deviations (RSDs) did not exceed 10% for three‐tested concentrations. The method was successfully applied to pharmacokinetic studies of BX enantiomers in rabbits. The result suggested that the pharmacokinetics of BX enantiomers was stereoselective in rabbits. Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Enantioselective disposition of PCB 136 (2,2′,3,3′,6,6′‐hexachlorobiphenyl) in C57BL/6 mice after oral and intraperitoneal administration
Authors: Kania‐Korwel Izabela , Shaikh Nadim S. , Hornbuckle Keri C. , Robertson Larry W. , Lehmler Hans‐Joachim 
Published: November 2006

AbstractStudies of xenobiotic disposition in rodents often employ experimental designs using differing routes of administration. In an effort to investigate the effects of route of administration on enantioselective disposition of xenobiotics, a chiral polychlorinated biphenyl (PCB), racemic PCB 136, was administered as a single dose (50 mg/kg body weight) to male or female C57BL/6 mice either orally or via intraperitoneal injection. Mice were sacrificed after either 3 or 6 days, and blood and organs were collected for PCB analysis. Intraperitoneal injection of PCB 136 produced statistically higher PCB levels in blood and organs than did the oral administration. Tissue levels were higher after 3 days than those after 6 days. Enantioselective analysis showed that (+)‐PCB 136 was enriched in most organs, with the most pronounced enrichment found in the liver and the brain of animals dosed orally or by intraperitoneal injection, respectively. Significantly higher retained enantiomeric fractions of PCB 136 were found in the oral treatment groups compared with those found in intraperitoneal treatment groups, possibly as a result of the lower PCB levels in oral treatment groups. Therefore, the choice of administration route may well have implications for the enantioselective disposition of PCB 136 and other chiral substances. Chirality, 2006. © 2006 Wiley‐Liss, Inc.
Fountain Flow™ cytometry, a new technique for the rapid detection and enumeration of microorganisms in aqueous samples
Authors: Johnson Paul E. , Deromedi Anthony J. , Lebaron Philippe , Catala Philippe , Cash Jennifer 
Published: November 2006

AbstractBackground:Pathogenic microorganisms are known to cause widespread waterborne disease worldwide. There is an urgent need to develop a technique for the real‐time detection of pathogens in environmental samples at low concentrations, <10 microorganisms/ml, in large sample volumes, ≥100 ml.Methods:A novel method, Fountain Flow™ cytometry, for the rapid and sensitive detection of individual microorganisms in aqueous samples is presented. Each sample is first incubated with a fluorescent label and then passed as a stream in front of a laser, which excites the label. The fluorescence is detected with a CCD imager as the sample flows toward the imager along its optical axis. The feasibility of Fountain Flow cytometry (FFC) is demonstrated by the detection of Escherichia coli labeled with ChemChrome CV6 and SYBR Gold in buffer and natural river water.Results:Detections of labeled E. coli were made in aqueous suspensions with an efficiency of 96% ± 14% down to a concentration ∼200 bacteria/ml.Conclusions:The feasibility of FFC is demonstrated by the detection of E. coli in buffer and natural river water. FFC should apply to the detection of a wide range of pathogenic microorganisms including amoebae. © 2006 International Society for Analytical Cytology
Mouse Rab11‐FIP4 regulates proliferation and differentiation of retinal progenitors in a Rab11‐independent manner
Authors: Muto Akihiko , Aoki Yutaka , Watanabe Sumiko 
Published: November 2006

AbstractWe identified Rab11‐family interacting protein 4 (Rab11‐FIP4) as a gene strongly expressed in the developing mouse retina. The major transcript encoding a full‐length protein, mRab11‐FIP4A, was expressed predominantly in neural tissues; whereas an alternative transcript encoding an N‐terminally truncated form of the protein, mRab11‐FIP4B, was expressed ubiquitously as a minor form. Gain‐of‐function of mRab11‐FIP4A in retina promoted cell cycle exit and increased subpopulations of retinal cells localized in the inner nuclear layer, such as bipolar cells and Müller glia. Reversal of the phenotype was observed in the loss‐of‐function experiment. Furthermore, Shh signaling was suggested to be involved in these functions. Analysis using truncation mutants revealed the essential role of the N‐terminal region containing a conserved EF‐hand motif for the retinal phenotypes induced by the expression of mRab11‐FIP4A, whereas binding to Rab11 was dispensable, suggesting the involvement of a novel Rab11‐independent mechanism for mRab11‐FIP4A action in the regulation of retinal development. Developmental Dynamics 236:214–225, 2007. © 2006 Wiley‐Liss, Inc.
Timing and sequence of the onset of overweight, dieting, and binge eating in overweight patients with binge eating disorder
Authors: Reas Deborah L. , Grilo Carlos M. 
Published: November 2006

AbstractObjective:To examine the self‐reported sequence and timing of onset of overweight, binge eating, and dieting in adult patients diagnosed with binge eating disorder (BED).Method:Participants were 284 treatment‐seeking adults (73 men and 211 women) who met DSM‐IV research criteria for BED. Patients were interviewed with structured diagnostic interviews and were queried regarding history of overweight, dieting, and binge eating behaviors. Questionnaires were also administered to assess current eating disturbances, body dissatisfaction, and general functioning. Participants were classified as Overweight First, Binge First, or Diet First, and the three groups were compared on developmental sequence and using the battery of measures.Results:Sixty‐three percent of the 284 participants reported becoming overweight prior to the onset of dieting or binge eating. Participants who reported they were overweight first had significantly greater BMI at the time of assessment. The 16% of the participants who reported binge eating first were significantly younger at the onset of BED diagnosis and reported significantly less dietary restraint. Onset order differed significantly by gender; proportionally more women (25%) than men (11%) reported that dieting preceded overweight or binge eating.Conclusion:Weight problems preceded dieting and binge eating behaviors for a majority of treatment‐seeking overweight participants diagnosed with BED. © 2006 by Wiley Periodicals, Inc. Int J Eat Disord 2006