bluuebunny/crossref_metadata_2025 huggingface dataset:
Production of a non‐triple helical collagen α chain in transgenic silkworms and its evaluation as a gelatin substitute for cell culture
Authors: Adachi Takahiro , Wang Xiaobiao , Murata Tomoko , Obara Masanobu , Akutsu Hidenori , Machida Masakazu , Umezawa Akirihiro , Tomita Masahiro
Published: April 2010

We generated transgenic silkworms that synthesized human type I collagen α1 chain [α1(I) chain] in the middle silk glands and secreted it into cocoons. The initial content of the recombinant α1(I) chain in the cocoons of the transgenic silkworms was 0.8%. The IE1 gene, a trans‐activator from the baculovirus, was introduced into the transgenic silkworm to increase the content of the chain. We also generated silkworms homozygous for the transgenes. These manipulations increased the α1(I) chain content to 8.0% (4.24 mg per cocoon). The α1(I) chain was extracted and purified from the cocoons using a very simple method. The α1(I) chain contained no hydroxyprolines due to the absence of prolyl‐hydroxylase activity in the silk glands. Circular dichroism analysis showed that the secondary structure of the α1(I) chain is similar to that of denatured type I collagen, demonstrating the absence of the triple helical structure. Human skin fibroblasts were seeded on the α1(I) chain‐coated dishes. The cells attached and spread, although at decreased chain concentrations the spreading rate was lower than that of the collagen and gelatin. Cynomolgus monkey embryonic stem cells cultured on the α1(I) chain‐coated dishes maintained an undifferentiated state after 30 passages, and their pluripotency was confirmed by teratoma formation in severe combined immunodeficient mice. These results show that the recombinant human α1(I) chain is a promising candidate biomaterial as a high‐quality and safe gelatin substitute for cell culture. Biotechnol. Bioeng. 2010;106: 860–870. © 2010 Wiley Periodicals, Inc.
The replacement of the Neumann trend test and the Durbin–Watson test on residuals by one‐way ANOVA with resampling and an extension of the tests to different time lags
Authors: Tóth Gergely
Published: April 2010

In our investigation we focused on the replacement and on the extension of two traditional parametric tests used for detecting trend and autocorrelation in time series. We found that the Neumann test of gradual trend and the Durbin–Watson test of residuals can be replaced by one‐way analysis of variance (ANOVA) with resampling. Resampling meant a proper choice of numerous pairs of data, where each pair consisted of two successive data points.

We extended the Neumann test, the Durbin–Watson test and our ANOVA method with the introduction of time lag. If the resampled data consisted of pairs with a time lag of h, we obtained a set of tests with different answers on the hypothesis at the h‐values. The time lag extended tests with resampling seemed to be efficient in the detection of hidden autocorrelation, trend and relevant time scales for data modelling.

The methods were compared on simple model data and on data of air pollutants recorded in Hungary. The Neumann(h) and the ANOVA(h) curves were specific for the different pollutant and helped to detect and explain local peculiarities. Copyright © 2010 John Wiley & Sons, Ltd.
Random projection experiments with chemometric data
Authors: Varmuza Kurt , Filzmoser Peter , Liebmann Bettina
Published: April 2010

Random projection (RP) is a linear method for the projection of high‐dimensional data onto a lower dimensional space. RP uses projection vectors (loading vectors) that consist of random numbers taken from a symmetric distribution with zero mean; many successful applications have been reported for high‐dimensional data sets. The basic ideas of RP are presented, and tested with artificial data, data from chemoinformatics and from chemometrics. RP's potential in dimensionality reduction is investigated by a subsequent cluster analysis, classification or calibration, and is compared to PCA as a reference method. RP allowed drastic reduction in data size and computing time, while preserving the performance quality. Successful applications are shown in structure similarity searches (53 478 chemical structures characterized by 1233 binary substructure descriptors) and in classification of mutagenicity (6506 chemical structures characterized by 1455 molecular descriptors). Only in calibration tasks with low‐dimensional data as in many chemical applications, RP showed limited performance. For special applications in chemometrics with very large data sets and/or severe restrictions for hardware and software resources, RP is a promising method. Copyright © 2010 John Wiley & Sons, Ltd.
Applicability domain for in silico models to achieve accuracy of experimental measurements
Authors: Sushko Iurii , Novotarskyi Sergii , Körner Robert , Pandey Anil Kumar , Kovalishyn Vasily V. , Prokopenko Volodymyr V. , Tetko Igor V.
Published: April 2010

The accuracy of in silico models can be inhomogeneous: models can show excellent performance on some chemical subspaces but have low accuracy on others. We show that applicability domain (AD) approaches can differentiate reliable and non‐reliable predictions and identify those with experimental accuracy for both regression and classification models. For reliably predicted molecules, the predicted values can be used instead of experimental measurements. This can halve time and costs of experimental measurements. The developed classification models for AMES mutagenicity test and CYP450 inhibition, which are important drug discovery properties, are publicly available at the online chemical database and modeling environment (OCHEM) site http://qspr.eu Copyright © 2010 John Wiley & Sons, Ltd.
Application of recurrent relations in chemistry
Authors: Zenkevich Igor G.
Published: April 2010

As it was previously demonstrated, mathematical properties of simplest first‐order recurrent relations A(n + 1) = aA(n) + b provide important advantages at their applications in chemistry, namely in the approximation of monotonous variations of different physicochemical properties of homologues of various series of organic compounds. Besides that it was empirically revealed the unique ‘chemical’ property of recurrences that is the application of single equations of this kind to constants of different series. To explain this high ‘approximating ability’ of recurrences it was proved first time that numerical sequences that obey high‐order recurrence in a limiting case can be approximated by first‐order recurrence. Consequently, this fact explains us the existence of close analogy between first‐order recurrent approximation of recursive numerical sequences (Fibonacci, Padovan, Lucas and Perrin sequences are considered as examples) and physicochemical constants of homologues. This analogy is considered as not ‘chemically’ correct proof, but reasonable explanation of the applicability of single recurrent equations to constants of different homologous series. The mentioned properties of recurrences seem to be the reason of their high approximating ability in relation to different chemical variables. Recurrent relations can be recommended as universal approach in processing of not only various sets of physicochemical constants of homologues, but also properties or processes characterized by equidistant values of arguments. Copyright © 2010 John Wiley & Sons, Ltd.
Impact of standardization sample design on Tikhonov regularization variants for spectroscopic calibration maintenance and transfer
Authors: Kunz Matthew R. , Ottaway Joshua , Kalivas John H. , Andries Erik
Published: April 2010

Multivariate spectroscopic calibration models are only valid to predict samples within the span of the calibration sample space measured relative to the current instrument environment (the primary conditions). Predicting samples in secondary conditions with new variances, same sample variances as the calibration space but a new instrument environment, or both, requires some form of continual model maintenance and/or transfer. Previous work has shown that a Tikhonov regularization (TR) approach is capable of accomplishing both tasks by updating the primary model based on only a few samples (transfer or standardization set) measured under the secondary conditions. A distinction of the TR design for calibration maintenance and transfer is a defined weighting scheme for the small set of standardization samples augmented to the full set of primary calibration samples. Critical to successful calibration maintenance or transfer is the standardization sample set composition, i.e. standardization samples should properly represent that are less secondary conditions. This paper reports on using TR‐based methods to investigate this issue and a consensus modeling approach is briefly evaluated. Copyright © 2010 John Wiley & Sons, Ltd.
Development of semi‐empirical electrotopological index using the atomic charge in QSPR/QSRR models for alcohols
Authors: Souza Érica Silva , Kuhnen Carlos Alberto , da Silva Junkes Berenice , Yunes Rosendo Augusto , Heinzen Vilma Edite Fonseca
Published: April 2010

The semi‐empirical electrotopological index (ISET) used for quantitative structure‐retention relationship (QSRR) models firstly developed for alkanes and alkenes, was remodeled for different organic compounds such as ketones, aldehydes and esters. In this study, the ISET was developed and optimized to describe the chromatographic retention of aliphatic alcohols on six different stationary phases (SE‐30, OV‐3, OV‐7, OV‐11, OV‐17 and OV‐25). The presence of a hydroxyl group leads to a charge redistribution increasing the interactions between these molecules and the stationary phases relative to the interactions between hydrocarbons and the same stationary phases. These considerations were included in the calculation of ISET. The simple linear regressions (SLR) between retention indices and the ISET for each stationary phase showed good statistical quality, high internal stability and good predictive ability for external groups, especially for stationary phases with low polarity. A single combined model, in which the McReynolds polarity term was added as a descriptor, was developed for all the data points for the stationary phases and the results were of satisfactory predictive quality. The efficiency and the applicability of the approach were demonstrated through the high quality quantitative structure‐property relationship (QSPR) model for the boiling point (BP). For this physical property 134 compounds were used; most of them were not included in the original data set employed to develop the ISET. Copyright © 2010 John Wiley & Sons, Ltd.
Deterministic fallacies and model validation
Authors: Hawkins Douglas M. , Kraker Jessica
Published: April 2010

Stochastic settings differ from deterministic ones in many subtle ways, making it easy to slip into errors through applying deterministic thinking inappropriately. We suspect this is the cause of much of the disagreement about model validation. A further technical issue is a common misapplication of cross‐validation, in which it is applied only partially, leading to incorrect results. Statistical theory and empirical investigation verify the efficacy of cross‐validation when it is applied correctly. In settings where data are relatively scarce, cross‐validation is attractive in that it makes the maximum possible use of all available information, at the cost of potentially substantial computation. The bootstrap is another method that makes full use of all available data for both model fitting and model validation, at a cost of substantially increased computation, and it shares many of the broad philosophical background of cross‐validation. Increasingly, the computational cost of these methods is not a major concern, leading to the recommendation, in most circumstances, to use cross‐validation or bootstrapping rather than the earlier standard method of splitting the available data into a learning and a testing portion. Copyright © 2010 John Wiley & Sons, Ltd.
The role of the C(2) configuration and methyl substitution on the catalytic activity of novel 2,3,3‐ and 2,7,7‐trimethyl‐substituted γ‐aminonorbornan‐2‐ols
Authors: Martínez Antonio García , Vilar Enrique Teso , Fraile Amelia García , Cerero Santiago de la Moya , Ruiz Paloma Martínez , Morillo Cristina Díaz
Published: April 2010

A new set of optically active 2,3,3‐ and 2,7,7‐trimethyl‐substituted γ‐aminonorbornan‐2‐ols have been obtained from 2‐methylenenorbornane‐1‐carbonitriles derived from (+)‐camphor and (−)‐fenchone and probed as chiral ligands for the enantioselective addition of diethylzinc to benzaldehyde. This has allowed the study of the structural factors influencing the chirality transfer, such as variation of the relative configuration at C(2) and steric hindrance at C(2), C(3), and C(7) positions of norbornane, which result in the observance of the important role played by the gem‐dimethyl position in γ‐aminonorbornan‐2‐exo‐ols. An empirical rationalization of the obtained experimental results has been realized on the basis of energetically‐favored diastereomeric Noyori‐like transition states. Chirality 2010. © 2010 Wiley‐Liss, Inc.
Factors affecting supramolecular exciton intensity
Authors: Simonyi Miklós
Published: April 2010

The effect of nonchromophoric additives on supramolecular exciton intensity was tested. Fatty acids and 1‐dodecanol decreased exciton intensity of the tightly packed aggregate of 6′R‐capsanthol‐3′‐on, whereas all esters studied increased exciton intensity. These results apparently confirm the validity of the treatment of Harada for supramolecular systems too. Chirality 2010. © 2010 Wiley‐Liss, Inc.
Mixing intensification for the mineral industry
Authors: Wu Jie , Graham Lachlan , Nguyen Bon
Published: April 2010

The modern mineral industry uses hydrometallurgical processes to extract metals from ores. Typically, a large volume of ore slurry is treated in mixing tanks in a mineral processing plant, for leaching, digestion, precipitation, and other chemical processing to obtain pure metals or concentrated ores. This paper discusses mixing intensification as a means to achieve process intensification for the mineral process industry. Areas where mixing intensification can be applied are illustrated with case examples. Among them, it was suggested that for slowly reacting slurry systems typical in the mineral processing operations, high solid loadings should be considered to boost throughput. Improved agitator energy efficiency can be achieved by removing baffles, at very high solid loadings. Slurry stratification in tanks can be used to boost either solids residence time or slurry through flow.
Theoretical pressure dependency of carbon dioxide solubility under hydrate–liquid water equilibrium
Authors: Bergeron Sebastien , Beltrán Juan G. , Macchi Arturo , Servio Phillip
Published: April 2010

The effect of pressure on carbon dioxide solubility in water is significantly smaller than that of temperature under hydrate–liquid water (H–Lw) equilibrium. As a result, experimental values of carbon dioxide solubility in the water rich liquid phase under H–Lw equilibrium are often inconclusive and in some cases contradictory. This work proposes a theoretical derivation, based on fundamental thermodynamics, of the gas hydrate former solubility dependency on pressure for any binary system under two‐phase equilibrium. The obtained expression is applied to the carbon dioxide–water system under both hydrate–liquid water and vapour–liquid water equilibrium. It is shown that the solubility of carbon dioxide in the water rich liquid phase increases with increasing pressure under H–Lw equilibrium. The predicted trend is then compared to the limited experimental data available in the literature.
Multiphase flow at the edge of a steam chamber
Authors: Sharma Jyotsna , Gates Ian D.
Published: April 2010

The use of steam‐assisted gravity drainage (SAGD) to recover bitumen from Athabasca deposits in Alberta has been growing. Butler [Butler, J. Can. Pet. Tech. 1985;24:42–51] derived a simple theory to calculate the production rate of oil during SAGD in an ideal reservoir. This simple and useful theory made several assumptions about the properties of the reservoir and operating conditions of the process. The theory also assumed that the highest mobility oil is at the edge of the steam chamber and that the oil phase velocity is highest at the chamber edge and reduces with distance into the oil sand. This research examines flow conditions at the edge of the steam chamber. Specifically, a new theory is derived that takes into account the impact of oil saturation and relative permeability on the oil mobility profile at the edge of a steam chamber. It is shown that the flow behaviour at the edge of a steam chamber is more complex and is not fully represented by Butler's theory. Contrary to Butler's theory, the oil mobility has its maximum some distance away from the edge of the steam chamber. The results reveal that the higher the thermal diffusivity of the oil sand, the deeper the location where the oil phase velocity is maximum. The developed model has been validated against published experimental and field data.
Modelling and simulation of an oxychlorination reactor in a fluidized bed
Authors: Moreira J. C. S. , Pires C. A. M.
Published: April 2010

Taking 1,2‐dichloroethane from the oxychlorination reaction is a commercially very important process due to the large application of the 1,2‐dichloroethane in the chemical industry of PVC production. This work presents the modeling and simulation of an oxychlorination reactor with a fluidized bed. The pseudo‐homogeneous model with one‐dimensional flow in steady state was applied based on the theory of fluidized bed in two phases. It allows the sensitivity analysis of the operational and project parameters of the reactor. The ordinary differential equations system that represents the mathematical model of the reactor was solved through the application of the numerical method of Newton–Raphson's. The results obtained have proved that the developed model represents the system suitably, in spite of the one‐dimensional model. The effect of different parameters was investigated through the sensitivity analysis, and the results show that the parameters that have the largest influence on the reactor performances are: fluidized bed height, bubble diameter, residence time, cupric chloride weight in the catalyst, and emulsion phase temperature.
Investigation of the local specific energy dissipation rates in a jet‐zone loop reactor for halogenation of ketones
Authors: Wiedemann Mathias , Schlüter Michael , Räbiger Norbert
Published: April 2010

Within the framework of process intensification there is a growing demand for novel reactor technologies. For the improvement of halogenation of ketones a jet‐zone loop reactor (JZR) is used, which leads to an enormous increase in yield and selectivity compared to stirred vessels (Kutschera et al., 2008). This JZR is a special jet loop reactor with high specific mass transfer performance and good macromixing behaviour. It is obvious that there is direct relation between the reaction and the hydrodynamics in the reactor. Despite several aspects of hydrodynamics in jet loop reactors have been investigated, the essential flow characteristics behind a two‐component jet are not sufficiently understood. In these investigations, the flow field in the jet zone of the JZR was analysed by 2D particle image velocimetry (PIV) and the kinetic energy dissipation rate ε was determined from the spatial gradients of the fluctuating velocity.
Comparison of Effects of Simvastatin Versus Atorvastatin on Oxidative Stress in Patients With Coronary Heart Disease
Authors: Li Jia , Sun Yan‐Ming , Wang Lan‐Feng , Li Zhu‐Qin , Pan Wei , Cao Hong‐Yan
Published: April 2010

Background

HMG‐CoA reductase inhibitors (statins) have antiatherogenic effects beyond their cholesterol‐lowing effect. Whether atorvastatin has a stronger antioxidant effect than other statins is uncertain.

Hypothesis

To determine the effects of simvastatin and atorvastatin on markers of oxidative stress in patients with coronary heart disease (CHD).

Methods

This study was comprised of 164 patients with CHD and a control population of 122 healthy subjects. The patients with CHD were divided into 2 groups and treated with either simvastatin 20 mg/day or atorvastatin 10 mg/day. The markers of oxidative stress were measured before and after 12 weeks of treatment.

Results

The effects of atorvastatin on reducing oxidative stress were significantly greater compared with those of simvastatin (P < 0.05). The changes in the markers of oxidative stress did not correlate with the changes in the plasma lipid profile (P > 0.05).

Conclusions

This study suggests that atorvastatin reduces oxidative stress more effectively than simvastatin. Copyright © 2010 Wiley Periodicals, Inc.
Prevalence and Prognosis of Chronic Obstructive Pulmonary Disease Among 8167 Middle Eastern Patients With Acute Coronary Syndrome
Authors: Hadi Hadi A. R. , Zubaid Mohammed , Mahmeed Wael Al , El‐Menyar Ayman A. , Ridha Mustafa , Alsheikh‐Ali Alawi A. , Singh Rajivir , Assad Nidal , Habib Khalid Al , Suwaidi Jassim Al
Published: April 2010

Background

The purpose of this study was to report the prevalence and the significance of clinically recognized chronic obstructive pulmonary disease (COPD) during acute coronary syndrome (ACS).

Hypothesis

COPD in patients with ACS is associated with worse outcome.

Methods

Data were derived from a prospective, multicenter, multinational study of 8167 consecutive patients hospitalized with ACS from February to June 2007 in 6 Middle Eastern countries. Data were analyzed according to the presence or absence of COPD. Demographic, management, and in‐hospital outcomes were compared.

Results

The prevalence of COPD was 5.3%. When compared with non‐COPD patients, COPD patients were older and more likely to have diabetes, hypertension, and dyslipidemia. Atypical presentations were more common in COPD patients (P = 0.001). COPD patients were less likely to be treated with thrombolytic therapy (P = 0.001), β‐blockers (P = 0.001), and glycoprotein IIb/IIIa inhibitors, and more likely to receive angiotensin‐converting enzyme (ACE) inhibitors. Although there was no difference in in‐hospital mortality between the 2 groups, patients with COPD were more likely to have heart failure (P = 0.001). Despite the fact that COPD patients with ST‐segment elevation myocardial infarction were less likely to receive thrombolytic therapy, they suffered more bleeding complications (2.8% vs 1%, P = 0.04), resulting in prolonged hospitalization. COPD was not an independent predictor of increased in‐hospital mortality.

Conclusions

In this large cohort of patients with ACS, the prevalence of COPD was 5·3%. Atypical presentation is common among COPD patients, and this may result in delayed therapy. ACS in COPD patients was associated with higher risk of heart failure and major bleeding complications without increased risk of in‐hospital mortality. Copyright © 2010 Wiley Periodicals, Inc.
Synthesis and in vitro and in vivo Antifungal Activity of the Hydroxy Metabolites of Saperconazole
Authors: Meerpoel Lieven , Heeres Jan , Backx Leo J. J. , Van der Veken Louis J. E. , Hendrickx Rob , Corens David , De Groot Alex , Leurs Stef , Van der Eycken Luc , Weerts Johan , Luyts Paul , Van Gerven Frans , Woestenborghs Filip A. A. , Van Breda Andre , Oris Michel , van Dorsselaer Pascal , Willemsens Gustaaf H. M. , Bellens Danny , Marichal Patrick J. M. G. , Vanden Bossche Hugo F. , Odds Frank C.
Published: April 2010

Herein we describe the scalable diastereoselective and enantioselective syntheses of eight enantiomers of hydroxy metabolites of saperconazole. The in vitro antifungal activity of the eight stereoisomers (compounds1–8) was compared against a broad panel ofCandida spp. (n=93),Aspergillus spp. (n=10),Cryptococcus spp. (n=19), and dermatophytes (n=27). The four 2Sisomers1–4of the new agent were generally slightly more active than the four 2Risomers5–8. All eight isomers were tested in a model of experimentalA. fumigatusinfection in guinea pigs by intravenous inoculation of the fungal conidia. Treatment doses were 1.25 mg kg−1and 2.5 mg kg−1per day. Infection severity was measured in terms of mean survival time (MST) after infection and mean tissue burdens in brain, liver, spleen, and kidney at postmortem examination. Among the eight isomers, the 2Sdiastereomers1–4showed a generally higher level of activity than the 2Rdiastereomers5–8, revealing compounds1and4as the most potent overall in eradicating tissue burden and MST. Compared with reference compounds itraconazole and saperconazole, the hydroxy isomers1–8are less potent inhibitors of the growth ofA. fumigatusin vitro and of ergosterol biosynthesis in bothA. fumigatusandC. albicans.
Size‐Dependent Binding Energies of Methane to Small Gold Clusters
Authors: Lang Sandra M. , Bernhardt Thorsten M. , Barnett Robert N. , Landman Uzi
Published: April 2010

The reactions of small gold cluster cations Aux+ (x=2–6) with CH4 were studied by joint gas‐phase kinetics and first‐principles density functional theory calculations. The experimentally obtained temperature‐dependent low pressure rate constants were analyzed by employing the Lindemann energy transfer model for association reactions in conjunction with statistical RRKM theory. In this way cluster‐size‐dependent binding energies of methane to the gold cluster cations were determined from the experimental data for two different transition‐state models. The experimental binding energies obtained by employing a “loose” transition‐state model are in good agreement with the theoretical values at the optimal adsorption geometries, while a “tight” transition‐state model clearly gives a lower limit for the binding energies. Additionally, Kohn–Sham molecular orbitals of AuxCH4+ are presented to gain detailed insight into the cluster–methane bonding mechanism.
The Diversity of Electron‐Transport Behaviors of Molecular Junctions: Correlation with the Electron‐Transport Pathway
Authors: Liu Hongmei , Yu Cui , Gao Nengyue , Zhao Jianwei
Published: April 2010

We report the electron‐transport behaviors of a number of molecular junctions composed of π‐conjugated molecular wires. From calculations performed by using density functional theory (DFT) combined with the non‐equilibrium Green’s function (NEGF) method, we found that the length–conductivity relations are diverse, depending on the particular molecular structures. The results reveal that the conductance–length dependence follows an exponential law for many conjugated molecules with a single channel, such as oligothiophene, oligopyrrole and oligophenylene. Therefore, a quantitative relation between the energy gap (Eg)∞ of the molecular wire and the attenuation factor β can be defined. However, when the molecular wires have multichannels, the decay of conductance does not follow the exponential relation. For example, the conductance of porphyrin‐based oligomers and fused thiophene decays almost linearly. The diversity of electron‐transport behaviors of molecular junctions is directly dominated by the electron‐transport pathway.
Liquid‐Phase Chemical Hydrogen Storage: Catalytic Hydrogen Generation under Ambient Conditions
Authors: Jiang Hai‐Long , Singh Sanjay Kumar , Yan Jun‐Min , Zhang Xin‐Bo , Xu Qiang
Published: April 2010

There is a demand for a sufficient and sustainable energy supply. Hence, the search for applicable hydrogen storage materials is extremely important owing to the diversified merits of hydrogen energy. Lithium and sodium borohydride, ammonia borane, hydrazine, and formic acid have been extensively investigated as promising hydrogen storage materials based on their relatively high hydrogen content. Significant advances, such as hydrogen generation temperatures and reaction kinetics, have been made in the catalytic hydrolysis of aqueous lithium and sodium borohydride and ammonia borane as well as in the catalytic decomposition of hydrous hydrazine and formic acid. In this Minireview we briefly survey the research progresses in catalytic hydrogen generation from these liquid‐phase chemical hydrogen storage materials.
Laser excitation power and the flow cytometric resolution of complex karyotypes
Authors: Ng Bee L. , Carter Nigel P.
Published: April 2010

The analytical resolution of individual chromosome peaks in the flow karyotype of cell lines is dependent on sample preparation and the detection sensitivity of the flow cytometer. We have investigated the effect of laser power on the resolution of chromosome peaks in cell lines with complex karyotypes. Chromosomes were prepared from a human gastric cancer cell line and a cell line from a patient with an abnormal phenotype using a modified polyamine isolation buffer. The stained chromosome suspensions were analyzed on a MoFlo sorter (Beckman Coulter) equipped with two water‐cooled lasers (Coherent). A bivariate flow karyotype was obtained from each of the cell lines at various laser power settings and compared to a karyotype generated using laser power settings of 300 mW. The best separation of chromosome peaks was obtained with laser powers of 300 mW. This study demonstrates the requirement for high‐laser powers for the accurate detection and purification of chromosomes, particularly from complex karyotypes, using a conventional flow cytometer. © 2010 International Society for Advancement of Cytometry
MS‐TOF Study of the Formation of Thiolato‐Bridged Rhodium Oligomers
Authors: Boudreau Josée , Grenier‐Desbiens Jérôme , Fontaine Frédéric‐Georges
Published: April 2010

The complex [Cp*Rh(μ‐SPh)3RhCp*]Cl was used as a starting material to synthesize various oligomeric materials of the general formula [Cp*Rh(μ‐SPh)x(μ‐Cl)3–x{Rh(μ‐SPh)3}nRhCp*] (x = 1 to 3; n = 1 to 4), which are formally formed by insertion of nRh(SPh)3 units into one μ‐Rh–SPh bond. The insertion of Ir(SPh)3 was also observed to generate theheterotrimetallic species. All complexes were observed by using HRMS‐TOF and [Cp*Rh(μ‐SPh)3Rh(μ‐SPh)3RhCp*]Cl, [3+]Cl, was characterized by using X‐ray crystallography.
A Bismuth‐Stabilized Metal‐Rich Telluride Lu9Bi≈1.0Te≈1.0 – Synthesis and Characterization
Authors: Gupta Shalabh , Maggard Paul A. , Corbett John D.
Published: April 2010

Synthetic reactions aimed at bismuth incorporation into rare‐earth‐metal‐rich tellurides yielded Lu9Bi≈1.00Te≈1.00 over a small range of compositions, but no analogues with Gd, Tb, Er, or Y. A single‐crystal X‐ray diffraction analysis gave the composition Lu9Bi0.99(3)Te1.01 in the acentric orthorhombic space group Cmc21 at ambient temperature. This is isostructural with the re‐refined Sc9Te2 earlier reported in a monoclinic Cc structure. Lu9Bi≈1.00Te≈1.00 represents the first ternary compound in this structure type and the third lutetium‐richest compound after Lu8Te and Lu7Te. The structure contains 3 × 3 columns of Lu in the form of condensed distorted trans‐edge‐sharing octahedral chains along a. The Te and Bi anions lie within tricapped trigonal prisms of Lu. Generally shorter Lu–Lu interactions lie in the interior of 3 × 3 metal columns compared with those on the periphery for which fewer Lu–Lu interactions and polar covalent bonding with neighboring tellurium weaken Lu–Lu bonding. Limiting Lu–Lu distances around 3.18 Å are by far the shortest among reduced lutetium tellurides. LMTO‐type ab initio electronic structure calculations reveal a metallic nature and show that strong polar bonding of Lu to both the more electronegative Bi and Te leaves Lu relatively oxidized, many 5d states falling above the Fermi level. Stronger Lu–Lu bonding within the metal columns is also indicated by their larger individual Hamilton populations. The isostructural Lu9SbTe and Sc9BiTe were also shown to exist according to powder data.
An Efficient Iron‐Catalyzed Carbon–Carbon Single‐Bond Cleavage via Retro‐Claisen Condensation: A Mild and Convenient Approach to Synthesize a Variety of Esters or Ketones
Authors: Biswas Srijit , Maiti Sukhendu , Jana Umasish
Published: April 2010

An efficient iron‐salt‐catalyzed carbon–carbon bond cleavage occurring through a retro‐Claisen condensation reaction has been developed. The reaction is useful for the synthesis of a variety of esters or ketones under mild conditions. This method works under solvent‐free conditions without the need of an inert atmosphere. This protocol is also applicable for the one‐pot syntheses of ketones through tandem carbon–carbon bond formation (substitution or Michael) followed by a retro‐Claisen reaction. However, for Michael adducts, ring annulation takes place subsequently. Notably, this method is very simple, convenient, high yielding, and only a catalytic (5 to 10 mol‐%) amount of Fe(OTf)3 is needed.
Asymmetric Total Synthesis of (+)‐6‐epi‐Castanospermine by the Stereoselective Formation of a syn,anti Acetylenic 2‐Amino‐1,3‐diol Stereotriad
Authors: Louvel Julien , Botuha Candice , Chemla Fabrice , Demont Emmanuel , Ferreira Franck , Pérez‐Luna Alejandro
Published: April 2010

The asymmetric total synthesis of (+)‐6‐epi‐castanospermine (1) is described herein. In this synthesis the diastereoselective addition of a racemic allenylzinc reagent to an enantiopure α‐alkoxy‐tert‐butylsulfinylimine is the key step and is followed by the formation of a piperidine ring by ring‐closing metathesis and subsequent syn‐dihydroxylation of an alkene.
Ionic Liquid as an Alternative Greener Sensing Medium for the Chemical Warfare Agent
Authors: Singh Virendra V. , Boopathi M. , Ganesan K. , Singh Beer , Vijayaraghavan R.
Published: April 2010

Greener electrochemical detection method developed for chemical warfare agent (CWA) nitrogen mustard‐2 (NM‐2) using room temperature ionic liquid (RTIL). The diffusion coefficient calculated for NM‐2 in acetonitrile and RTIL was 1.57×10−4 cm2/s and 1.82×10−10 cm2/s, respectively. NM‐2 addition to RTIL enhanced RTIL conductivity. Moreover, heterogeneous rate constant (0.192 s−1), transfer coefficient (0.231) and the number of electron involved (1.0) were deduced for NM‐2 in RTIL. The calibration plot showed linearity between 2.94×10−5 and 1.17×10−3 M with detection limit 1.47 ×10−5 M (S/N=3). The large number of available RTIL can be used for greener detection of toxic CWAs.
Tris(2,2′‐bipyridyl)ruthenium(II) Electrogenerated Chemiluminescence Sensor Based on Platinized Carbon Nanotube–Zirconia–Nafion Composite Films
Authors: Yoon Sook Hyun , Han Jee Hoon , Kim Byung Kun , Choi Han Nim , Lee Won‐Yong
Published: April 2010

Mesoporous films of platinized carbon nanotube–zirconia–Nafion composite have been used for the immobilization of tris(2,2′‐bipyridyl)ruthenium (II) (Ru(bpy)32+) on an electrode surface to yield a solid‐state electrogenerated chemiluminescence (ECL) sensor. The composite films of Pt–CNT–zirconia–Nafion exhibit much larger pore diameter (3.55 nm) than that of Nafion (2.82 nm) and thus leading to much larger ECL response for tripropylamine (TPA) because of the fast diffusion of the analyte within the films. Due to the conducting and electrocatalytic features of CNTs and Pt nanoparticles, their incorporation into the zirconia–Nafion composite films resulted in the decreased electron transfer resistance within the films. The present ECL sensor based on the Pt–CNT–zirconia–Nafion gave a linear response (R2=0.999) for TPA concentration from 3.0 nM to 1.0 mM with a remarkable detection limit (S/N=3) of 1.0 nM, which is much lower compared to those obtained with the ECL sensors based on other types of sol‐gel ceramic–Nafion composite films such as silica–Nafion and titania–Nafion.
A Comparative Study of Modifying Gold and Carbon Electrode with 4‐Sulfophenyl Diazonium Salt
Authors: Gui Alicia L. , Liu Guozhen , Chockalingam Muthukumar , Le Saux Guillaume , Harper Jason B. , Gooding J. Justin
Published: April 2010

A comparison of the reductive adsorption behavior of 4‐sulfophenyl diazonium salt and subsequent electrochemical reactivity on gold relative to carbon was studied with some significant differences observed. The ability of the 4‐sulfophenyl layer adsorbed onto gold to block access of the redox probe ferricyanide to the underlying electrodes, as determined via cyclic voltammetry was inferior to the same layers formed on glassy carbon electrodes thus indicating a more open, porous layer formed on gold. More significantly, the 4‐sulfophenyl layers are shown to be far less electrochemically stable on gold than on glassy carbon. Electrochemical and X‐ray photoelectron spectroscopy (XPS) evidence suggests the instability is due to cleavage of the bond between sulfonate functional group and phenyl ring. These results provide further evidence that although aryl diazonium salt layers are relatively stable on gold surfaces compared with alkanethiol based self‐assembled monolayer (SAMs), the stability is not as high as is observed on carbon.
Transforming the distribution of OFDM signals for peak‐to‐average power ratio reduction
Authors: Zhu Xiaodong , Zhu Guangxi , Lin Pei
Published: April 2010

Large peak‐to‐average power ratio (PAPR) is the main drawback of orthogonal frequency division multiplexing (OFDM) systems. In this paper, a novel nonlinear scheme is proposed to reduce the PAPR. This scheme transforms the amplitude of original OFDM signals from Rayleigh distribution into beta distribution. Moreover, given different parameters, this scheme has different transformation expressions. It is demonstrated that the well‐known companding schemes based on exponential function and error function are actually the special cases of the proposed scheme. Further, we derive another simpler expression of the proposed scheme. Simulation results show that the new transformation can achieve a better tradeoff between PAPR reduction and bit‐error rate (BER) performance than the exponential function and error function companding schemes. Copyright © 2010 John Wiley & Sons, Ltd.
Selective mapping for reduced complexity turbo channel estimation operating on highly time and frequency selective channels
Authors: Châabouni Sihem , Siala Mohamed , Sellami Noura
Published: April 2010

In this paper, we consider a time division multiple access (TDMA) transmission of coded symbols over a time and frequency selective channel. At the receiver, a turbo‐detector composed of a maximuma posteriori(MAP) equaliser and a MAP decoder is used. We give the expression of the MAP iterative burst‐by‐burst channel estimation algorithm using the Expectation‐Maximisation (EM) algorithm. Since the obtained algorithm is complex, we propose to simplify it by neglecting the inter‐symbol interference (ISI) term. In order to reduce the error caused by this simplification, we propose to use a candidate precoder at the transmitter chosen among a given set of precoders such that the selected precoded sequence leads to the minimum mean square value of the ISI neglected term. Simulations show that the performance of the approximate algorithm with precoding are almost similar to the performance of the exact algorithm. Copyright © 2010 John Wiley & Sons, Ltd.
Trust management in wireless sensor networks
Authors: Zahariadis Theodore , Leligou Helen C. , Trakadas Panagiotis , Voliotis Stamatis
Published: April 2010

The range of applications of wireless sensor networks is so wide that it tends to invade our every day life. In the future, a sensor network will survey our health, our home, the roads we follow, the office or the industry we work in or even the aircrafts we use, in an attempt to enhance our safety. However, the wireless sensor networks themselves are prone to security attacks. The list of security attacks, although already very long, continues to augment impeding the expansion of these networks. The trust management schemes consist of a powerful tool for the detection of unexpected node behaviours (either faulty or malicious). Once misbehaving nodes are detected, their neighbours can use this information to avoid cooperating with them, either for data forwarding, data aggregation or any other cooperative function. A variety of trust models which follow different directions regarding the distribution of measurement functionality, the monitored behaviours and the way measurements are used to calculate/define the node's trustworthiness has been presented in the literature. In this paper, we survey trust models in an attempt to explore the interplay among the implementation requirements, the resource consumption and the achieved security. Our goal is to draw guidelines for the design of deployable trust model designs with respect to the available node and network capabilities and application peculiarities. Copyright © 2010 John Wiley & Sons, Ltd.
Two‐phase pressure drop caused by sudden flow area contraction/expansion in small circular pipes
Authors: Roul Manmatha K. , Dash Sukanta K.
Published: April 2010

Theoretical studies have been made to determine the pressure drops caused by abrupt flow area expansion/contraction in small circular pipes for two‐phase flow of air and water mixtures at room temperature and near atmospheric pressure. Two‐phase computational fluid dynamics (CFD) calculations, using Eulerian–Eulerian model (with the air phase being compressible for pipe contraction case) are employed to calculate the pressure drop across sudden expansion and contraction. The pressure drop is determined by extrapolating the computed pressure profiles upstream and downstream of the expansion/contraction. The larger and smaller tube diameters are 1.6 and 0.84 mm, respectively. Computations have been performed with single‐phase water and air, and two‐phase mixtures in a range of Reynolds number (considering all‐liquid flow) from 1000 to 12 000 and flow quality from 1.2 × 10−3to 1.6 × 10−2. The numerical results are validated against experimental data from the literature and are found to be in good agreement. The expansion and contraction loss coefficients are found to be different for single‐phase flow of air and water, and they agreed reasonably well with the commonly used theoretical predictions. Based on the numerical results as well as experimental data, correlations are developed for two‐phase flow pressure drops caused by the flow area contraction as well as expansion. Copyright © 2010 John Wiley & Sons, Ltd.
Volume‐tracking of subgrid particles
Authors: Sun Mingyu
Published: April 2010

A new PLIC‐VOF method is proposed to track deformable particles, such as bubbles and liquid droplets, that can be smaller than the grid spacing. The idea is to replace the surface normal (SN) calculation used in the PLIC, by the SN vector obtained from partial differential equations that are solved together with the advection algorithm. The equations for the evolution of SN vector are derived, and examined by using the first‐order and the second‐order upwind schemes. Since the normal vector is defined in every cell, the method generally improves the accuracy at low grid resolution. It is found that a normal vector of zero magnitude is located at the centroid of a particle, to second‐order accuracy for small particles. The motion of a subgrid particle is controlled by the arrival of the zero vector in the present PLIC/SN method, so that the particle can be translated at the right speed without any additional treatment. This has been numerically verified by simulating a particle of one‐tenth of grid spacing traveling in three different directions, in addition to a few typical test cases. Copyright © 2010 John Wiley & Sons, Ltd.
Fitness Versus Fatness: Moving Beyond Weight Loss in Nonalcoholic Fatty Liver Disease
Authors: Johnson Nathan A. , George Jacob
Published: April 2010

The rapid emergence of nonalcoholic fatty liver disease (NAFLD) as a cause of both liver-related morbidity and mortality and cardiometabolic risk has led to the search for effective lifestyle strategies to reduce liver fat. Lifestyle intervention comprising dietary restriction in conjunction with increased physical activity has shown clear hepatic benefits when weight loss approximating 3%-10% of body weight is achieved. Yet, the poor sustainability of weight loss challenges the current therapeutic focus on body weight and highlights the need for alternative strategies for NAFLD management. Epidemiologic data show an independent relationship between liver fat, physical activity, and fitness, and a growing body of longitudinal research demonstrates that increased physical activity participation

per se

significantly reduces hepatic steatosis and serum aminotransferases in individuals with NAFLD, independent of weight loss. Mechanistic insights to explain this interaction are outlined, and recommendations for the implementation of lifestyle intervention involving physical activity are discussed. In light of the often poor sustainability of weight loss strategies, and the viability of physical activity therapy, clinicians should assess physical fitness and physical activity habits, educate patients on the benefits of fitness outside of weight loss, and focus on behavior change which promotes physical activity adoption. (Hepatology 2010)
Comparing video‐rate STED nanoscopy and confocal microscopy of living neurons
Authors: Lauterbach Marcel A. , Keller Jan , Schönle Andreas , Kamin Dirk , Westphal Volker , Rizzoli Silvio O. , Hell Stefan W.
Published: April 2010

We compare the performance of video‐rate Stimulated Emission Depletion (STED) and confocal microscopy in imaging the interior of living neurons. A lateral resolution of 65 nm is observed in STED movies of 28 frames per second, which is 4‐fold higher in spatial resolution than in their confocal counterparts. STED microscopy, but not confocal microscopy, allows discrimination of single features at high spatial densities. Specific patterns of movement within the confined space of the axon are revealed in STED microscopy, while confocal imaging is limited to reporting gross motion. Further progress is to be expected, as we demonstrate that the use of continuous wave (CW) beams for excitation and STED is viable for video‐rate STED recording of living neurons. Tentatively providing a larger photon flux, CW beams should facilitate extending fast STED imaging towards imaging fainter living samples. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A tissue adhesives evaluated in vitro and in vivo analysis
Authors: Mo Xiumei , Iwata Hiroo , Ikada Yoshito
Published: April 2010

In this study, three kinds of two‐component adhesive glues were prepared, namely, gel‐dext glue made from modified gelatin and dextran, gel‐HES glue made from modified gelatin and hydroxyethyl starch (HES), and chit‐dext glue made from chitosan and modified dextran. Upon mixing the two‐component solution together crosslinking occurred and a gel formed in several seconds, which would seal the wound tissue and stop the bleeding. The adhesive ability of those three prepared glues was evaluated in vitro and in vivo separately by measuring the bonding strength to two piece of porcine skin and the adhesive strength after sealing the skin incisions on the back of rat. Fibrin glue was used as comparing. Gel‐dext glue and gel‐HES glue shown higher bonding strength and adhesive strength than chit‐dext glue and fibrin glue. Histology test of incision tissues given by both HE and MTC methods, the former shown that gel‐dext and gel‐HES glues, like fibrin glue, have only normal initial inflammation to skin tissue, which almost disappear from 9 days but chit‐dext glue seams have heaver inflammation, which may last to 12 days; the later shown gel‐dext and gel‐HES glues similar to fibrin glue, can heal the wound fast than that of chit‐dext glue. The hemostatic ability for gel‐HES glue was also tested on a cut liver of rat, which depend on the gel formation speed when the two‐composite solutions were mixed together. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010