bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of neferine on the pharmacokinetics of amiodarone in rats
Authors: Wan Jiadao , Zhao Libo , Xu Chuan , Zhang Shaohui , Zhang Zhixin , Zeng Cheng , Chang Mujun , Xiao Junhua , Wang Jialing
Published: November 2010

Amiodarone, an iodinated benzofuran derivative with predominantly class III anti‐arrhythmic effects, is used to treat supraventricular and ventricular arrhythmias. The purpose of this study was to assess the potential of neferine, an effective anti‐pulmonary fibrosis drug isolated from the embryo of Nelumbo nucifera Gaertner's seeds, to alter the pharmacokinetic profile of amiodarone. Experimental Sprague–Dawley rats were randomly divided into two groups. In groups 1 and 2, amiodarone was given to rats by intragastric and intravenous administration, respectively, while neferine was co‐administratered by intragastric administration. Blood samples were collected from the orbital venous plexus at indicated time points and were analyzed for amiodarone concentration using RP‐HPLC. The geometric mean ratio for Cmax and AUC0–96 was calculated. There were no significant differences between the pharmacokinetics parameters of amiodarone administered intravenously or intragastrically and the control (without neferine) group (with ratios of 0.7–1.4 in all experimental groups), suggesting that neferine had no effect on amiodarone plasma pharmacokinetics. The dosage regimen of amiodarone does not need to be taken into consideration when combined with neferine. Copyright © 2010 John Wiley & Sons, Ltd.
Towards Practical Baeyer–Villiger‐Monooxygenases: Design of Cyclohexanone Monooxygenase Mutants with Enhanced Oxidative Stability
Authors: Opperman Diederik J. , Reetz Manfred T.
Published: November 2010

Baeyer–Villiger monooxygenases (BVMOs) catalyze the conversion of ketones and cyclic ketones into esters and lactones, respectively. Cyclohexanone monooxygenase (CHMO) from Acinetobacter sp. NCIMB 9871 is known to show an impressive substrate scope as well as exquisite chemo‐, regio‐, and enantioselectivity in many cases. Large‐scale synthetic applications of CHMO are hampered, however, by the instability of the enzyme. Oxidation of cysteine and methionine residues contributes to this instability. Designed mutations of all the methionine and cysteine residues in the CHMO wild type (WT) showed that the amino acids labile towards oxidation are mostly either surface‐exposed or located within the active site, whereas the two methionine residues identified for thermostabilization are buried within the folded protein. Combinatorial mutations gave rise to two stabilized mutants with either oxidative or thermal stability, without compromising the activity or stereoselectivity of the enzyme. The most oxidatively stabilized mutant retained nearly 40 % of its activity after incubation with H2O2 (0.2 M), whereas the wild‐type enzyme's activity was completely abolished at concentrations as low as 5 mM H2O2. We propose that oxidation‐stable mutants might well be a “prerequisite” for thermostabilization, because laboratory‐evolved thermostability in CHMO might be masked by a high degree of oxidation instability.
Photochemical Water Decomposition in the Troposphere: DFT Study with a Symmetrized Kohn–Sham Formalism
Authors: Minaev Boris F. , Zakharov Ivan I. , Zakharova Olga I. , Tselishtev Alexei B. , Filonchook Anton V. , Shevchenko Alexandr V.
Published: November 2010

Photochemical reaction of the electronically excited NO2* species with the water molecule is studied in terms of a new version of density functional theory by selecting the specific 2A′′ symmetry of the whole system, which is different from the ground‐state pattern. The excited  2A2 state of the NO2 molecule is found to be distorted to the equilibrium structure ONO., which poses the 2A′′ symmetry in the Cs point group. With the B3LYP functional it is shown that such an electronically excited NO2* molecule, generated by visible light (λ=420 nm), can react with water vapor to produce OH+HONO species, an important source of tropospheric hydroxyl radicals. This photochemical process can be considered as a possible mechanism of atmosphere self‐cleaning.
On the Relative Merits of Equilibrium and Non‐Equilibrium Simulations for the Estimation of Free‐Energy Differences
Authors: Daura Xavier , Affentranger Roman , Mark Alan E.
Published: November 2010

The possibility of estimating equilibrium free‐energy profiles from multiple non‐equilibrium simulations using the fluctuation–dissipation theory or the relation proposed by Jarzynski has attracted much attention. Although the Jarzynski estimator has poor convergence properties for simulations far from equilibrium, corrections have been derived for cases in which the work is Gaussian distributed. Here, we examine the utility of corrections proposed by Gore and collaborators using a simple dissipative system as a test case. The system consists of a single methane‐like particle in explicit water. The Jarzynski equality is used to estimate the change in free energy associated with pulling the methane particle a distance of 3.9 nm at rates ranging from ∼0.1 to 100 m s−1. It is shown that although the corrections proposed by Gore and collaborators have excellent numerical performance, the profiles still converge slowly. Even when the corrections are applied in an ideal case where the work distribution is necessarily Gaussian, performing simulations under quasi‐equilibrium conditions is still most efficient. Furthermore, it is shown that even for a single methane molecule in water, pulling rates as low as 1 m s−1 can be problematic. The implications of this finding for studies in which small molecules or even large biomolecules are pulled through inhomogeneous environments at similar pulling rates are discussed.
Biradicaloid Character of Thiophene‐Based Heterophenoquinones: The Role of Electron–Phonon Coupling
Authors: Fazzi Daniele , Canesi Eleonora V. , Negri Fabrizia , Bertarelli Chiara , Castiglioni Chiara
Published: November 2010

The quinoidal versus biradicaloid character of the ground state of a series of thiophene‐based heterophenoquinones is investigated with quantum‐chemical calculations. The role of the ground‐state electronic character on molecular structure and vibrational properties is emphasized. The vibrational activities are experimentally determined and their analysis is performed by taking advantage of the definition of a collective vibrational coordinate (the

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coordinate) maximizing the electron–phonon coupling, and connecting the quinoid and the aromatic biradicaloid resonance structures. The combined experimental and computational investigation supports the biradicaloid nature of the longer oligomers. The modulation of Raman intensities and frequency dispersion, experimentally observed by increasing the length of the chromophore, is shown to be reproduced well by model calculations on a single chromophore as a function of geometry displacements along the

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‐mode. These results underline the role of electron–phonon coupling in governing the structure–property relationship of highly conjugated organic compounds, underscoring the similarity of thiophene heterophenoquinone systems with other, more classical, oligophenylene and oligothiophene derivatives.
The Origin and Dynamics of Soft X‐Ray‐Excited Optical Luminescence of ZnO
Authors: Armelao Lidia , Heigl Franziskus , Brunet Sophie , Sammynaiken Ramaswami , Regier Tom , Blyth Robert I. R. , Zuin Lucia , Sankari Rami , Vogt Johannes , Sham Tsun‐Kong
Published: November 2010

The distinct optical emission from ZnO materials, nanoneedles and microcrystallites synthesized with different sizes and morphologies by a flow deposition technique, is investigated with X‐ray excited optical luminescence (XEOL) and time‐resolved X‐ray excited optical luminescence (TR‐XEOL) from a synchrotron light source at the O K and Zn L3,2 edges. The innovative use of XEOL, allowing site‐specific chemical information and luminescence information at the same time, is fundamental to provide direct evidence for the different behaviour and the crucial role of bulk and surface defects in the origin of ZnO optical emission, including dynamics. XEOL from highly crystalline ZnO nanoneedles is characterized by a sharp band‐gap emission (∼380 nm) and a broad red luminescence (∼680 nm) related to surface defects. Luminescence from ZnO microcrystallites is mostly dominated by green emission (∼510 nm) associated with defects in the core. TR‐XEOL experiments show considerably faster decay dynamics in nanoneedles compared to microcrystallites for both band‐gap emission and visible luminescence. Herein we make a fundamental step forward correlating for the first time the interplay of size, crystallinity, morphology and excitation energy with luminescence from ZnO materials.
Complex spatial networks in application
Authors: Evans Andrew J.
Published: November 2010

The last five years has seen a considerable growth in the application of graph and network theory to “real‐world” networks. Many of these networks are “spatial” in that their form and dynamics are limited by the distance between nodes in Euclidian space. This paper reviews some of the advances in the analysis of such real‐world networks, highlights the continuing difficulties involved, and points to areas that need further work before a network analysis can become a standard field of application for those wishing to understand and predict real‐world systems. © 2010 Wiley Periodicals, Inc. Complexity 16: 11–15, 2010
The cytologic findings in choroid plexus carcinoma: Report of a case with differential diagnosis
Authors: Savage Natasha M. , Crosby John H. , Reid‐Nicholson Michelle D.
Published: November 2010

Choroid plexus carcinoma is a rare tumor of the choroid plexus that shows frank cytologic features of malignancy including frequent mitoses, increased cellularity, nuclear pleomorphism, loss of papillary architecture, and necrosis. It occurs predominantly in the pediatric population and is associated with a poor prognosis. We report the cerebrospinal fluid and intraoperative squash preparation cytologic findings of a case of choroid plexus carcinoma arising in the lateral ventricle of a 16‐year‒old girl who developed tumor recurrence in cerebrospinal fluid 6 years after initial resection. To the best of our knowledge, there are only a few reports in the English literature describing the cytologic features of choroid plexus carcinoma. Relevant differentials and the usefulness of ancillary studies in diagnosis are also discussed. Diagn. Cytopathol. 2012. © 2010 Wiley Periodicals, Inc.
Papanicolaou's nebular cells are related to HPV infection and HSIL
Authors: Roeters Anne M.E. , Boon Mathilde E. , van Haaften Maarten , Vernooij Floor , Romke Bontekoe Tj. , Heintz, A. Peter M.
Published: November 2010

Metaplastic cells with nebular cytoplasmic changes in the cervical smear are classified in the Dutch coding system for cervical screening as KOPAC O8 cells. Since these nebulated cells are already documented by Papanicolaou, we refer to these cells as Papanicolaou's nebular cells.

We examined the simultaneous presence of these characteristic metaplastic cells and high‐grade squamous intraepithelial lesion (HSIL) in a population‐based data base from January 1991 and December 1996.

The odds ratio (OR) of nebular cells concurring with HSIL increases with age. For the age cohort 30 years, the OR was 7.8 with a 95% confidence interval (CI) of 4.4–13.9. For the age cohort 60 years, the OR was 35.3 with a 95% CI of 7.8–159.2. Aiming to determine the nature of these nebular metaplastic cells, we performed Chlamydia and HPV PCR on 587 and 1,483 smears, respectively. With an OR of 0.9 [0.3–2.4] it is unlikely that Chlamydia plays a role in the appearance of these nebular cells in the smear. This study shows that with an OR of 5.9 [1.7–21.3] HPV is not only related to large koilocytosis but also to a nebular change of small metaplastic cells.

This study reports that nebular changes of small metaplastic cells are related to cervical cancer and to HPV infection. Diagn. Cytopathol. 2012. © 2010 Wiley Periodicals, Inc.
HSIL, epithelial cell abnormality‐adjusted workload, and the Thinprep imaging system
Authors: Renshaw Andrew A. , Elsheikh Tarik M.
Published: November 2010

Previous studies have suggested that the sensitivity of the ThinPrep Imaging System (TIS) for high‐grade intraepithelial lesion (HSIL) and worse may be decreased at workloads above 100 slides/day. On the other hand, at a threshold of atypical squamous cells of undetermined significance (ASCUS) and above, sensitivity of the TIS appears to more closely correlated with epithelial cell abnormality (ECA)‐adjusted workload (ECA rate × actual slides/day) rather than total workload. We sought to determine if the sensitivity of the TIS for HSIL could also be shown to be correlated with ECA‐adjusted workload. The change in sensitivity for HSIL from manual screening to TIS screening consistently correlated negatively with ECA‐adjusted workload both in the original Food and Drug Administration trial study and in independent studies available in the literature. Both sources suggest that sensitivity near 100% can be achieved with ECA‐adjusted workloads of 5–7 slides/day. For a laboratory with an ECA rate of 10%, this represents a total workload of 50–70 slides/day. We conclude that measuring the ECA‐adjusted workload is a valuable method to assess workload for the ThinPrep Imaging System. Diagn. Cytopathol. 2012. © 2010 Wiley Periodicals, Inc.
Primary leiomyosarcoma of the prostate with lung metastasis: Report of a case diagnosed by fine‐needle aspiration cytology
Authors: Barwad Adarsh , Khandelwal Niranjan , Vyas Sameer , Gogoi, Dhrubajyoti , Dey Pranab
Published: November 2010

Prostate leiomyosarcoma is an extremely rare and highly aggressive neoplasm that accounts for less than 0.1% of primary prostate malignancies. Herein, we present a patient with primary leiomyosarcoma of the prostate with lung metastasis diagnosed primarily on fine‐needle aspiration cytology. Characteristic cytological features such as small fascicles of spindle cells with blunt‐ended nuclei, positivity for desmin and smooth muscle actin along with the radiological features are helpful in the correct diagnosis. Diagn. Cytopathol. 2010. © 2010 Wiley‐Liss, Inc.
The decrement in circulating endothelial progenitor cells (EPCs) in type 2 diabetes is independent of the severity of the hypoadiponectemia
Authors: Li Mingfang , Ho Jenny C. Y. , Lai Kevin W. H. , Au Karen K. W. , Xu Aimin , Cheung Bernard M. Y. , Lam Karen S. L. , Tse Hung‐Fat
Published: November 2010

Background

Type 2 diabetes mellitus (DM) is associated with a decreased level of circulating endothelial progenitor cells (EPCs) and adiponectin. Experimental studies suggest a potential link between hypoadiponectinaemia and the depletion of the EPC level. This study investigated the relationships between adiponectin level and EPC in patients with type 2 DM.

Methods

A total of 95 type 2 DM patients (58.5 ± 8.8 years, 42 men) and 95 age‐ and sex‐matched healthy controls were recruited. Circulating EPC levels were determined by flow cytometry using CD133+, CD34+, CD133+/KDR+ and CD34+/KDR+ as surface markers. Plasma adiponectin levels were measured by enzyme‐linked immunosorbent assay. EPC function was studied by in vitro tube formation and migration assay.

Results

The levels of CD133+ (p < 0.001) and CD133+/KDR+ (p < 0.001) EPCs were independently associated with the presence of type 2 DM. The levels of CD34+ (p = 0.004) and CD34+/KDR+ (p = 0.013) EPCs were independently associated with haemoglobin A$_{\rm{1c}}$. Nevertheless, there was no relationship between the number of EPCs and adiponectin level. Tube formation assay showed impaired pro‐angiogenic function of EPC in DM patients compared with controls (p = 0.007). Interestingly, adiponectin supplementation (5 µg/mL) increased tube formation by 17.6% in EPCs from DM patients (p = 0.002). It also significantly enhanced cell migration by 35.9% in EPCs from DM patients (p = 0.01).

Conclusions

We detected no relationship between the reduction in the level of EPC and in the level of total adiponectin in blood from patients with type 2 diabetes. EPC from patients with diabetes were stimulated when exposed to adiponectin in the test tube, findings that warrant further study. Copyright © 2011 John Wiley & Sons, Ltd.
Study of the endogenous steroid profile of male athletes from the Brazilian National Soccer Championship 2009
Authors: Nicolich Rebecca S. , Padilha Monica C. , de Aquino Neto Francisco R.
Published: November 2010

Changes in the endogenous profile of androgenic anabolic steroids (AAS) may be interpreted as markers of doping. The objective of this study was to evaluate the endogenous profile of AAS in male athletes of the 2009 Brazilian National Soccer Championship, in normal conditions, particularly in the light of the revision of World Anti‐Doping Agency's (WADA) Technical Document on the Interpretation of Endogenous AAS in athletes for doping control drafted in that year, as well as comparing these results to profiles already published in the literature. The upper limit of the 95% central reference interval of the following parameters for the studied population were estimated to be significantly higher than WADA's criteria, with a confidence of 90%: DHEA (about 2.3 times higher), Adiol (1.2 times higher), Bdiol (2.7 times higher), and Adiol/E (6 times higher). These findings seem to imply that WADA's criteria proposed in 2009 for DHEA, Adiol, Bdiol, and Adiol/E may not have been applicable to the studied population. Moreover, their comparison to previously published studies pointed to the need to evaluate in detail the appropriateness of adopting these criteria as universal, since there seems to be variations among different populations of athletes. Copyright © 2010 John Wiley & Sons, Ltd.
Reporting and managing elevated testosterone/epitestosterone ratios—Novel aspects after five years' experience
Authors: Mareck Ute , Geyer Hans , Fußhöller Gregor , Schwenke Anne , Haenelt Nadine , Piper Thomas , Thevis Mario , Schänzer Wilhelm
Published: November 2010

The testosterone/epitestosterone (T/E) ratio was implemented as an indirect parameter for the detection of testosterone administration with an empirically established threshold value at T/E = 6. In 2005, the T/E reporting threshold was lowered from six to four.

Between 2005 and 2009, 63 510 doping control urine samples were analyzed in the Cologne laboratory. A total of 1442 specimens (2.3%) showed a T/E > 4; 80 (5.5%) of which were tested positive by means of isotope ratio mass spectrometry (IRMS); and most of which (68) originated from strength sport disciplines.

Specimens of high T/E ratio showed a much higher probability for being confirmed to contain exogenous testosterone using IRMS analysis than samples of low T/E values.

Considering the small number of adverse analytical findings triggered by lowering the T/E reporting threshold (978 urine specimens with T/E ratios between 4 and 6 yielded only 4 (0.4%) positive IRMS findings) and the known limitations of the T/E ratio as discriminating parameter (UGT2B17 polymorphism), the currently mandatory approach shows only marginal overall efficiency.

A more effective tool for the detection of the misuse of testosterone would be the implementation of individual reference ranges. Until athlete steroidal passports are available, it is suggested to exceed the threshold level for T/E from 4 to 6 and perform obligatory IRMS analysis for specimens showing T/E > 6. Further conditions triggering IRMS analysis could be suppressed luteinizing hormone (LH) values in males and disproportionate changes of relevant parameters in individual profiles evidently not resulting from ethanol consumption. Copyright © 2010 John Wiley & Sons, Ltd.
Acamprosate in the treatment of binge eating disorder: A placebo‐controlled trial
Authors: McElroy Susan L. , Guerdjikova Anna I. , Winstanley Erin L. , O'Melia Anne M. , Mori Nicole , McCoy Jessica , Keck Paul E. , Hudson James I.
Published: November 2010

Objective:

To assess preliminarily the effectiveness of acamprosate in binge eating disorder (BED).

Method:

In this 10‐week, randomized, placebo‐controlled, flexible dose trial, 40 outpatients with BED received acamprosate (N = 20) or placebo (N = 20). The primary outcome measure was binge eating episode frequency.

Results:

While acamprosate was not associated with a significantly greater rate of reduction in binge eating episode frequency or any other measure in the primary longitudinal analysis, in the endpoint analysis it was associated with statistically significant improvements in binge day frequency and measures of obsessive‐compulsiveness of binge eating, food craving, and quality of life. Among completers, weight and BMI decreased slightly in the acamprosate group but increased in the placebo group.

Discussion:

Although acamprosate did not separate from placebo on any outcome variable in the longitudinal analysis, results of the endpoint and completer analyses suggest the drug may have some utility in BED. © 2010 by Wiley Periodicals, Inc. (Int J Eat Disord 2011; 44:81–90)
Adolescent–Adult discrepancies on the eating disorder examination: A function of developmental stage or severity of illness?
Authors: Loeb Katharine L. , Jones Jennifer , Roberto Christina A. , Sonia Gugga S. , Marcus Sue M. , Attia Evelyn , Timothy Walsh B.
Published: November 2010

Objective:

Across studies, adolescents score lower on measures of eating disorder pathology than adults, but it is unclear whether such findings reflect discrepancies inherent to site/study or true developmental differences. The aim of this study was to determine whether age predicts subscale and diagnostic scores of the Eating Disorder Examination (EDE) in adolescents and adults with anorexia nervosa (AN) admitted to a single research center within the same period of time.

Method:

The sample consisted of 16 adolescent and 20 adult consecutive admissions to parallel, age‐specific, research‐based AN treatment programs. Participants completed a baseline evaluation at admission that included the EDE, depression measures, and global assessment of functioning scales.

Results:

Age significantly predicted EDE scores in univariate regression analyses. However, in multivariate models that included severity indices of general and specific psychopathology as covariates, age was no longer a significant predictor of severity of eating disorder symptoms.

Discussion:

This study adds to the growing body of data showing lower scores on the EDE for adolescents with AN relative to their adult counterparts, while eliminating potential site confounds. Results indicate that the higher adult scores may be carried in part by a more overall severe and chronic general clinical profile. © 2010 by Wiley Periodicals, Inc. (Int J Eat Disord 2011)
Modelling effects of land use/cover changes under limited data
Authors: Wang Ruoyu , Kalin Latif
Published: November 2010

Watershed models are valuable tools used in the study of impacts of land use/cover (LULC) changes on hydrology. We use the Soil and Water Assessment Tool (SWAT) to study the impacts of LULC changes in a coastal Alabama watershed, where flow data did not exist at the onset of the study. We set up and calibrated the model in the neighbouring Magnolia River watershed. Relevant model parameters were then transferred to the Wolf Bay watershed. Impacts of LULC changes on hydrology are studied in the Wolf Bay watershed by running the model with the default parameters, transferred model parameters (from the Magnolia River watershed), and calibrated parameters at the Wolf Bay watershed with limited data that became available later during the study. The relative changes in flow duration curves (FDCs) due to differing LULC showed a similar pattern with each parameter set: There is a clear threshold of around 1% probability of exceedance where the relative change is at its maximum. The relative change in flow due to LULC change drops drastically with increasing probability of exceedance of beyond 2% until it reaches a plateau at p = 20%. Hence, small to medium range flows are less sensitive to the parameter set. Further, the impact of LULC change on flow gradually decreases with the size of the storm for very large events (probability of exceedance < 1%). Copyright © 2010 John Wiley & Sons, Ltd.
[FeFe]‐Hydrogenase Models: Unexpected Variation in Protonation Rate between Dithiolate Bridge Analogues
Authors: Aušra Jablonskytė  , Wright Joseph A. , Pickett Christopher J.
Published: November 2010

The model [FeFe]‐hydrogenase subsite Fe2(μ‐odt)(CO)4(PMe3)2 (odt = 2‐oxapropane‐1,3‐dithiolate) has been crystallized for the first time, revealing an apical–basal arrangement of the two phosphane groups. Protonation of this species has been studied by a combination of stopped‐flow ultraviolet and infrared techniques along with time‐resolved NMR spectroscopy. The kinetics of the protonation are similar to those for Fe2(μ‐edt)(CO)4(PMe3)2 (edt = ethane‐1,2‐dithiolate) and are much slower than those for the protonation of Fe2(μ‐pdt)(CO)4(PMe3)2 (pdt = propane‐1,3‐dithiolate). The dithiolate bridge length is therefore not the key determinant of reactivity in these simple model systems.
A Stereoselective and Practical Synthesis of (E)‐α,β‐Unsaturated Ketones from Aldehydes
Authors: Balducci Evita , Attolino Emanuele , Taddei Maurizio
Published: November 2010

α,β‐Unsaturated ketones can be prepared by reaction of differently substituted β‐keto acids and aldehydes. The reaction is carried out under organocatalysis (β‐alanine, 0.5 equiv.) and generates the enones with high E selectivity (>95 %). This version of the Verley–Doebner modification of the Knoevenagel reaction is a practical alternative to the classic Horner–Wadsworth–Emmons (HWE) reaction without the formation of high molecular weight byproducts. The process makes use of simple reagents and can be applied to large‐scale synthesis under conditions compatible with atom‐economy principles. Differently substituted aliphatic, aromatic, or heteroaromatic α,β‐unsaturated ketones can be prepared. An example of a hydroformylation/Verley–Doebner Knoevenagel telescoped process is also described.
Chemical and Electrochemical Extraction of Ytterbium from Molten Chlorides in Pyrochemical Processes
Authors: Castrillejo Y. , Fernández P. , Medina J. , Vega M. , Barrado E.
Published: November 2010

The electrochemical behaviour of ytterbium ions was investigated in the eutectic LiCl‐KCl at 723 K at the surface of tungsten, glassy carbon, aluminium and aluminium coated tungsten electrodes. On inert electrodes (W and GC) the electroreduction of Yb(III) to Yb(II) takes place in a quasi‐reversible electrochemical mode within the electroactive window. The electrochemical system Yb(II)/Yb(0) is not observed because it is similar or more negative in potential than the Li(I)/Li(0) couple. As a result Yb metal in contact with the melt could react to give Li(0) according to the reaction: Yb(0)+2Li(I)↔Yb(II)+2Li(0) On the contrary, on reactive Al electrodes the electrochemical system Yb(II)/Yb(0) was observed within the electroactive range. The potential shift of the redox couple is caused by the decrease of Yb activity in the metal phase due to the formation of Yb‐Al alloys at the interface. The formation mechanism of the alloys was determined in a melt containing both Yb(III) and Al(III) ions, using W, Al and Al coated tungsten electrodes. X‐ray diffraction analysis and scanning electron microscopy (SEM) after potentiostatic electrolysis runs allowed the identification of Al3Yb and Al2Yb. Potentiometric titrations of Yb(III) solutions with oxide donors, using a ytria stabilized circonia membrane electrode “YSZME” as a pO2− indicator electrode, have shown the formation of ytterbium oxychloride and ytterbium oxide and their solubility products have been determined at 723 K (pks(Yb2O3)=7.6±0.3 and pks(YbOCl)=18.5±0.7.
Preparation and Characterization of a Molecularly Imprinted Microgel for Electrochemical Sensing of 2,4,6‐Trichlorophenol
Authors: Díaz‐Díaz Goretti , Blanco‐López M. Carmen , Lobo‐Castañón M. Jesús , Miranda‐Ordieres Arturo J. , Tuñón‐Blanco Paulino
Published: November 2010

This article describes the synthesis and characterization of a catalytic 2,4,6‐trichlorophenol molecularly imprinted microgel that could replace a natural chloroperoxidase to develop electrochemical sensors. This polymer exhibits an apparent mean particle size of 1–4 µm and high porosity, and mimics the dehalogenative function of the natural enzyme chloroperoxidase for p‐halophenols. Two strategies were explored: a carbon paste modified with the polymer and the drop‐coating of screen‐printed electrodes with powder suspensions of the polymer and carbon nanotubes. With this last design, TCP concentrations above 25 µM could be detected. The sensor developed this way could be used for environmental waste screening.
Electrophoretically deposited polyaniline nanotubes based film for cholesterol detection
Authors: Dhand Chetna , Solanki Pratima R. , Pandey Manoj K. , Datta Monika , Malhotra Bansi D.
Published: November 2010

Polyaniline nanotube (PANI‐NT) based films have been fabricated onto indium‐tin‐oxide (ITO) coated glass plates via electrophoretic technique. These PANI‐NT/ITO electrodes have been utilized for covalent immobilization of cholesterol oxidase (ChOx) using glutaraldehyde (Glu) as cross‐linker. Structural, morphological and electrochemical characterization of PANI‐NT/ITO electrode and ChOx/Glu/PANI‐NT/ITO bioelectrode have been done using FT‐IR spectroscopy, SEM, electrochemical impedance spectroscopy and cyclic voltammetry techniques. Response studies of the ChOx/Glu/PANI‐NT/ITO bioelectrode have been carried out using both linear sweep voltammetry and UV‐Visible spectrophotometry. The results of the biosensing studies reveal that this bioelectrode can be used to detect cholesterol in wide detection range of 25–500 mg/dL with high sensitivity of 3.36 mA mg−1 dL and fast response time of 30 s at pH 7.4. This bioelectrode exhibits very low value of Michaelis–Menten constant of 1.18 mM indicating enhanced interactions between cholesterol and ChOx immobilized onto this nanostructured PANI matrix.
Step width, spacing, and resolution in gradient elution moving boundary electrophoresis. Part 1. Theory and comparison with zone electrophoresis
Authors: Ross David
Published: November 2010

Gradient elution moving boundary electrophoresis (GEMBE) is a recently described technique for electrophoretic separations in short capillaries or microchannels. With GEMBE, the electrophoretic migration of analytes is opposed by a bulk counterflow of separation buffer. The counterflow velocity is varied over the course of a separation so that analytes with different mobilities enter the separation channel at different times and are detected as moving boundary, step‐wise increases in the detector response. The resolution of a GEMBE separation is thus dependent on the rate at which the counterflow velocity is varied, and relatively high‐resolution separations can be performed with short microfluidic channels or capillaries. In this paper, a theoretical description of GEMBE is presented that can be used for calculation of expected resolution and for optimization of GEMBE separations. A comparison is made with CZE, a conventional electrophoretic separation technique for which the theoretical understanding is mature. The results indicate that the electric field strength and separation channel length are important parameters for both CZE and GEMBE. However, with GEMBE, the counterflow acceleration is also available as a parameter that can be easily adjusted for optimization of the trade‐off between resolution and separation time. This allows for optimization of GEMBE separations by making changes only to the software controlling the apparatus rather than to the hardware of the apparatus itself. Further comparison of the theoretical descriptions of GEMBE and CZE indicates that the time required to achieve a desired resolution is equivalent for the two techniques.
Step width, spacing, and resolution in gradient elution moving boundary electrophoresis. Part 2. Results from experiment
Authors: Ross David
Published: November 2010

In Part 1 of this work, a theoretical description of gradient elution moving boundary electrophoresis (GEMBE) is presented along with a comparison between GEMBE and the more conventional technique of CZE. In this second part, experimental results are presented for comparison with the theoretical predictions of Part 1. Results for the step width, spacing, and resolution are examined as a function of the salient parameters affecting the results of a GEMBE separation (starting pressure, counterflow acceleration, and electric field strength).
Establishment of an ectopically expressed and functional PRMT1 for proteomic analysis of arginine‐methylated proteins
Authors: Chang Yuan‐I , Lin Sheng‐Wei , Chiou Yi‐Ying , Sung Jung‐Sung , Cheng Lee‐Chun , Lu Yu‐Ling , Sun Kuang‐Hui , Chang Keejong , Lin Chao‐Hsiung , Lin Wey‐Jinq
Published: November 2010

Protein arginine methylation, catalyzed by protein arginine methyltransferases (PRMTs), plays crucial roles in a variety of cellular processes. Mammalian PRMT1 exists in a large protein complex in cells, which has been implied in modulating the regulatory and catalytic properties of this enzyme. Establishment of a mammalian comparative approach will help to identify putative substrates of PRMT1 in an authentic condition. Here, we showed that ectopically expressed PRMT1 in mammalian HEK293 cells not only exhibited catalytic properties comparable to the endogenous enzyme but also existed in a functional complex together with endogenous PRMT1 and thus functioned as an endogenous counterpart. In addition, the measured methylation level of cellular proteins using a tritium‐labeled methyl donor was accordingly enhanced upon ectopic expression of PRMT1. Subsequent proteomic analysis with such PRMT1‐expressing cells allowed us to identify several known and putative methylated proteins. In vitro methylation of selected proteins, eukaryotic translation initiation factor 4A‐I and vimentin, by cellular PRMT1 was shown. Together, we have demonstrated the functional equivalence of ectopically expressed PRMT1 in HEK293 cells and its application to systematically identify the substrate proteins in a mammalian cell context.
Electrothermal flow effects in insulating (electrodeless) dielectrophoresis systems
Authors: Hawkins Benjamin G. , Kirby Brian J.
Published: November 2010

We simulate electrothermally induced flow in polymeric, insulator‐based dielectrophoresis (iDEP) systems with DC‐offset, AC electric fields at finite thermal Péclet number, and we identify key regimes where electrothermal (ET) effects enhance particle deflection and trapping. We study a single, two‐dimensional constriction in channel depth with parametric variations in electric field, channel geometry, fluid conductivity, particle electrophoretic (EP) mobility, and channel electroosmotic (EO) mobility. We report the effects of increasing particle EP mobility, channel EO mobility, and AC and DC field magnitudes on the mean constriction temperature and particle behavior. Specifically, we quantify particle deflection and trapping, referring to the deviation of particles from their pathlines due to dielectrophoresis as they pass a const riction and the stagnation of particles due to negative dielectrophoresis near a constriction, respectively. This work includes the coupling between fluid, heat, and electromagnetic phenomena via temperature‐dependent physical parameters. Results indicate that the temperature distribution depends strongly on the fluid conductivity and electric field magnitude, and particle deflection and trapping depend strongly on the channel geometry. Electrothermal (ET) effects perturb the EO flow field, creating vorticity near the channel constriction and enhancing the deflection and trapping effects. ET effects alter particle deflection and trapping responses in insulator‐based dielectrophoresis devices, especially at intermediate device aspect ratios (2≤r≤7) in solutions of higher conductivity (σm≥1×10−3 S/m). The impact of ET effects on particle deflection and trapping are diminished when particle EP mobility or channel EO mobility is high. In almost all cases, ET effects enhance negative dielectrophoretic particle deflection and trapping phenomena.
Predicting the Direction of the Fed's Target Rate
Authors: Kauppi Heikki
Published: November 2010

Predicting the direction of central banks' target interest rates is important for various market participants. This paper advances procedures for predicting the direction of the federal funds target rate using a dynamic extension of the multinomial logit model. I find that the 6‐month Treasury bill spread relative to the federal funds rate, the unemployment rate and the real GDP growth rate have superior predictive content for the direction of the target a week to several months ahead. When these variables are employed, lagged target changes do not provide additional predictive power. This suggests that the apparent positive serial dependence of the target changes is due to the Fed's systematic response to autocorrelated macroeconomic variables. Copyright © 2010 John Wiley & Sons, Ltd.
Synthesis of novel aminomethylenebisphosphonates and bisphosphonic acids, containing adamantyl fragment
Authors: Minaeva Lidiya I. , Patrikeeva Ludmila S. , Kabachnik Maria M. , Beletskaya Irina P. , Orlinson Boris S. , Novakov Ivan A.
Published: November 2010

Novel aminomethylenebisphosphonates containing an adamantyl fragment were synthesized by a solvent‐free, microwave‐assisted, three‐component reaction of amines, triethyl orthoformate, and O,O‐diethyl phosphite. Several bisphophonic acids were prepared from aminomethylenebisphosphonates by the treatment with trimethylsilyl bromide followed by methanolysis. © 2010 Wiley Periodicals, Inc. Heteroatom Chem 22:55–58, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/hc.20656
Quantitatively and qualitatively different cellular processes are engaged in CA1 during the consolidation and reconsolidation of contextual fear memory
Authors: Barnes Philip , Kirtley Anne , Thomas Kerrie L.
Published: November 2010

Whether the consolidation and reconsolidation long‐term memory relies on qualitatively different molecular and cellular processes is controversial. Using a novel experimental strategy of combining intrahippocampal antisense oligodeoxynucleotides targeting BDNF or zif268 to the block consolidation or reconsolidation of contextual fear memory respectively, and Affymetrix microarray technology, we identified a comprehensive list of nonoverlapping candidate genes regulated in CA1 during the initial stages consolidation and reconsolidation. Using RT‐qPCR in subsequent validation experiments, we estimated that over 80% of the candidates reflect gene transcripts truly regulated following the acquisition or retrieval of contextual fear memory. Statistical and over‐representation bioinformatics analyses revealed that cellular processes and signaling mechanisms were differentially regulated during consolidation and reconsolidation, particularly those associated with pro‐inflammatory cytokine signaling. This predicts that the two mnemonic processes are qualitatively as well as quantitatively distinct. This experimental strategy was further validated because the cytokine interleukin 1 (IL‐1) was reciprocally regulated in CA1 after contextual fear conditioning and fear memory retrieval, and we showed for the first time that that IL‐1 receptor mediated signaling in the hippocampus was necessary for reconsolidation. © 2010 Wiley Periodicals, Inc.
Control of anterodorsal thalamic head direction cells by environmental boundaries: Comparison with conflicting distal landmarks
Authors: Clark Benjamin J. , Harris Mark J. , Taube Jeffrey S.
Published: November 2010

Experiments were conducted to determine whether environmental boundaries exert preferential control over the tuning of head direction (HD) cells. In each experiment, HD cells were recorded in the rat anterodorsal thalamus while they foraged for randomly scattered food in trapezoid‐ and rectangle‐shaped environments. After an initial recording session, each environment was rotated 90°, and changes in the preferred firing directions of HD cells were monitored. Rats were disoriented before each test session to prevent the use of self‐movement cues to maintain orientation from one session to the next. In Experiment 1, we demonstrate that HD cell tuning consistently shifted in register with the trapezoid shaped enclosure, but was more variable in the rectangle shaped environment. In Experiments 2 and 3, we show that the strong control by the trapezoid persists in the presence of one clearly visible distal landmark, but not when three or more distal landmarks, including view of the recording room, are present. Together, the results indicate that distinct environmental boundaries exert strong stimulus control over HD cell orientation. However, this geometric control can be overridden with a sufficient number of salient distal landmarks. These results stand in contrast to the view that information from geometric cues usually takes precedence over information from landmark cues. © 2010 Wiley Periodicals, Inc.
Spatial representations in dorsal hippocampal neurons during a tactile‐visual conditional discrimination task
Authors: Griffin Amy L. , Owens Cullen B. , Peters Gregory J. , Adelman Peter C. , Cline Kathryn M.
Published: November 2010

Trajectory‐dependent coding in dorsal CA1 of hippocampus has been evident in various spatial memory tasks aiming to model episodic memory. Hippocampal neurons are considered to be trajectory‐dependent if the neuron has a place field located on an overlapping segment of two trajectories and exhibits a reliable difference in firing rate between the two trajectories. It is unclear whether trajectory‐dependent coding in hippocampus is a mechanism used by the rat to solve spatial memory tasks. A first step in answering this question is to compare results between studies using tasks that require spatial working memory and those that do not. We recorded single units from dorsal CA1 of hippocampus during performance of a discrete‐trial, tactile‐visual conditional discrimination (CD) task in a T‐maze. In this task, removable floor inserts that differ in texture and appearance cue the rat to visit either the left or right goal arm to receive a food reward. Our goal was to assess whether trajectory coding would be evident in the CD task. Our results show that trajectory coding was rare in the CD task, with only 12 of 71 cells with place fields on the maze stem showing a significant firing rate difference between left and right trials. For comparison, we recorded from dorsal CA1 during the acquisition and performance of a continuous spatial alternation task identical to that used in previous studies and found a proportion of trajectory coding neurons similar to what has been previously reported. Our data suggest that trajectory coding is not a universal mechanism used by the hippocampus to disambiguate similar trajectories, and instead may be more likely to appear in tasks that require the animal to retrieve information about a past trajectory, particularly in tasks that are continuous rather than discrete in nature. © 2010 Wiley Periodicals, Inc.
Surfactant and irrigation effects on wettable soils: runoff, erosion, and water retention responses
Authors: Lehrsch G. A. , Sojka R. E. , Reed J. L. , Henderson R. A. , Kostka S. J.
Published: November 2010

Surfactants are chemical compounds that can change the contact angle of a water drop on solid surfaces and are commonly used to increase infiltration into water repellent soil. Since production fields with water repellent soil often contain areas of wettable soil, surfactants applied to such fields worldwide will likely be applied to wettable soil, with unknown consequences for irrigation‐induced erosion, runoff, or soil water relations. We evaluated surfactant and simulated sprinkler irrigation effects on these responses for three wettable, Pacific Northwest soils, Latahco and Rad silt loams, and Quincy sand. Along with an untreated control, we studied three surfactants: an alkyl polyglycoside (APG) in solution at a concentration of 18 g active ingredient (AI) kg−1, a block copolymer at 26 g kg−1, and a blend of the two at 43 g kg−1. From 2005 to 2009 in the laboratory, each surfactant was sprayed at a rate of 46·8 l ha−1 onto each soil packed by tamping into 1·2‐ by 1·5‐m steel boxes. Thereafter, each treated soil was irrigated twice at 88 mm h−1 with surfactant‐free well water. After each irrigation, runoff and sediment loss were measured and soil samples were collected. While measured properties differed among soils and irrigations, surfactants had no effect on runoff, sediment loss, splash loss, or tension infiltration, compared to the control. Across all soils, however, the APG increased volumetric water contents by about 3% (significant at p≤0·08) at matric potentials from 0 to − 20 kPa compared to the control. With a decrease in the liquid–solid contact angle on treated soil surfaces, surfactant‐free water appeared able to enter, and be retained in pores with diameters ≥ 15 µm. All told, surfactants applied at economic rates to these wettable Pacific Northwest soils posed little risk of increasing either runoff or erosion or harming soil water relations. Moreover, by increasing water retention at high potentials, surfactants applied to wettable soils may allow water containing pesticides or other agricultural chemicals to better penetrate soil pores, thereby increasing the efficacy of the co‐applied materials. Copyright © 2010 John Wiley & Sons, Ltd.
Permafrost‐thaw‐induced land‐cover change in the Canadian subarctic: implications for water resources
Authors: Quinton W.L. , Hayashi M. , Chasmer L.E.
Published: November 2010

Climate warming and human disturbance in north‐western Canada have been accompanied by degradation of permafrost, which introduces considerable uncertainty to the future availability of northern freshwater resources. This study demonstrates the rate and spatial pattern of permafrost loss in a region that typifies the southern boundary of permafrost. Remote‐sensing analysis of a 1·0 km2 area indicates that permafrost occupied 0·70 km2 in 1947 and decreased with time to 0·43 km2 by 2008. Ground‐based measurements demonstrate the importance of horizontal heat flows in thawing discontinuous permafrost, and show that such thaw produces dramatic land‐cover changes that can alter basin runoff production in this region. A major challenge to northern water resources management in the twenty‐first century therefore lies in predicting stream flows dynamically in the context of widely occurring permafrost thaw. The need for appropriate water resource planning, mitigation, and adaptation strategies is explained. Copyright © 2010 John Wiley & Sons, Ltd.
An approach to the scaling problem in hydrological modelling: the deterministic modelling hydrological system
Authors: Vinogradov Yu. B. , Semenova O. M. , Vinogradova T. A.
Published: November 2010

A brief description of the Deterministic Modelling Hydrological System (DMHS) ‘Runoff–Erosion–Pollution’ proposed by the first author is presented. This system is being developed with the aim of giving it a universal character so that it can be applied in mountainous and flat terrain, and in basins of different natural climatic zones regardless of their size. The main feature of the model is its independence of the scaling problem. The basis of our approach consists of a simple theory of runoff elements. This is different from the generally accepted use of partial differential equations such as the Saint Venant equation for surface and channel flow and the Boussinesq equation for underground waters describing the water movement from runoff formation origins to the basin outlet. The results of runoff simulation for six mountainous watersheds of different sizes across Eastern Siberia within the Lena River basin and their statistical evaluation are presented. The selected river basins ranged in size from about 40 km2 (small scale) to the entire Lena River basin (2·4 million km2), classified as a large‐scale basin. Copyright © 2010 John Wiley & Sons, Ltd.