bluuebunny/crossref_metadata_2025 huggingface dataset:
Batch Grinding in Laboratory Ball Mills: Selection Function
Authors: Matijašic G. , Glasnovic A.
Published: September 2009

The selection functions and the breakage distribution functions are based on the experimentally‐determined particle size distribution on the basis of comminution of one size fraction particles. Therefore, to obtain a clear picture of the product properties during comminution of the “real” polydisperse sample, a number of experiments are needed. This work introduces the tested methodology for the selection function determination based on the starting and maximal values of the selection function. The principle was tested on the planetary ball mill and the horizontal laboratory ball mill, and according to the results obtained, it can be concluded that the proposed methodology can be useful for the evaluation of the selection function during batch comminution in different mills.
Fixed‐Bed Adsorption Study for Fumaric Acid Removal from Aqueous Solutions by Amberlite IRA‐400 Resin
Authors: Fu Y.‐Q. , Chen Y. , Li S. , Huang H.
Published: September 2009

A fixed‐bed adsorption study was carried out by using a strong base anion‐exchange resin (Amberlite IRA‐400) for the removal of fumaric acid from aqueous solutions. The breakthrough curves were obtained as a function of flow rate, temperature, feed pH, and inlet fumaric acid concentration. The total adsorption capacity and the percent fumaric acid removal of the resin were calculated. The Yoon‐Nelson model was applied to the experimental data to predict the breakthrough curves and to determine the characteristic column parameters required for process design. The breakthrough curves fit the model predictions well.
Three‐Dimensional Computational Fluid Dynamics Modeling of a Planar Solid Oxide Fuel Cell
Authors: Ni M.
Published: September 2009

A three‐dimensional computational fluid dynamics model was developed to study the performance of a planar solid oxide fuel cell (SOFC). The governing equations were solved with the finite volume method. The model was validated by comparing the simulation results with data from literature. Parametric simulations were performed to investigate the coupled heat/mass transfer and electrochemical reactions in a planar SOFC. Different from previous two‐dimensional studies the present three‐dimensional analyses revealed that the current density was higher at the center along the flow channel while lower under the interconnect ribs, due to slower diffusion of gas species under the ribs. The effects of inlet gas flow rate and electrode porosity on SOFC performance were examined as well. The analyses provide a better understanding of the working mechanisms of SOFCs. The model can serve as a useful tool for SOFC design optimization.
Accessing Novel Process Windows in a High‐Temperature/Pressure Capillary Flow Reactor
Authors: Razzaq T. , Glasnov T. N. , Kappe C. O.
Published: September 2009

High‐temperature/pressure organic synthesis can be performed under continuous flow conditions in a stainless steel microtubular flow reactor capable of achieving temperatures of 350 °C and 200 bar (X‐Cube Flash™). Using these extreme experimental environments, the Claisen rearrangement of allyl phenyl ether together with the ensuing rearrangement chemistry of the resulting 2‐allylphenol product was investigated. Reaction optimization was performed by changing the temperatures, pressures and flow rates “on‐the‐fly”. In addition, the high‐temperature/pressure flow system allowed the study of these transformations in low boiling point solvents in or near their supercritical state. In general, the chemistry optimized under high‐temperature microwave batch conditions could be successfully translated to a scalable flow regime.
Developing an Application Analytical Solution of Adiabatic Heat and Mass Transfer Processes in a Liquid Desiccant Dehumidifier/Regenerator
Authors: Babakhani D.
Published: September 2009

An analytical solution of simultaneous heat and mass transfer processes in a packed bed liquid desiccant dehumidifier/regenerator is developed. Various dimensionless parameters and reliable assumptions are used in order to develop this solution. The outlet parameters predicted with the analytical solution show very good agreement with the experimental data available in the literature. The results show that using a Lewis number value of Le = 1.1 instead of Le = 1 gives a better prediction of the performance of the dehumidifier. In addition, the use of Le = 0.9 instead of Le = 1 can give a better prediction of the outlet parameters of the regenerator. The benefits of the present solution are its simplicity and easy application for the simulation of air dehumidification and liquid desiccant regeneration processes.
A fictitious domain method for simulating viscous flow in a constricted elastic tube subject to a uniform external pressure
Authors: Wang Tong , Pan Tsorng‐Whay , Glowinski Roland
Published: September 2009

Stenosis of vascular type is an abnormal narrowing in a blood vessel. It is a common cause of some cardiovascular illnesses, such as stroke. A nonlinear mathematical model with a free moving boundary is used to model axisymmetric elastic tube with constriction subjected to a uniform external pressure and a prescribed pressure drop. A distributed Lagrange multiplier based fictitious domain method combined with operator splitting techniques and finite element method has been developed to simulate viscous incompressible flow in the above channel. The motion of the free moving tube wall is obtained by a prediction–relaxation technique. Numerical results and convergence studies are presented in this paper. Copyright © 2009 John Wiley & Sons, Ltd.
Concomitant activation of P2Y2 and P2Y6 receptors on monocytes is required for TLR1/2‐induced neutrophil migration by regulating IL‐8 secretion
Authors: Ben Yebdri Fethia , Kukulski Filip , Tremblay Alain , Sévigny Jean
Published: September 2009

Extracellular nucleotides regulate a variety of cellular responses involved in inflammation via the activation of P2 receptors. Here, we show that nucleotides regulate TLR2‐induced neutrophil migration both in vivo and in vitro. The nucleotide scavenger apyrase inhibited neutrophil recruitment in murine air pouches injected with the TLR2 agonist Pam3CSK4. In agreement, the supernatants of either human primary monocytes or monocytic cells (THP‐1 and U937) treated with Pam3CSK4 recruited significantly fewer neutrophils when the former cells were treated in the presence of apyrase. As demonstrated with inhibitory Ab, these supernatants induced neutrophil migration due to IL‐8 secretion. In addition, IL‐8 secretion was markedly diminished by the non‐selective P2 receptor antagonists reactive blue 2 and suramin, and by a selective P2Y6 antagonist, MRS2578. Selective antagonists of P2Y1 (MRS2500) and P2Y11 (NF157) did not affect IL‐8 release. The knockdown of either P2Y2 or P2Y6 with specific shRNA diminished IL‐8 secretion from Pam3CSK4‐treated THP‐1 cells. Altogether, these results show that extracellular nucleotides, via P2Y2 and P2Y6 receptors, regulate neutrophil migration by controlling TLR2‐induced IL‐8 release from human monocytes. In line with our previous work on TLR4, this study further supports the importance of nucleotides in bacterial‐induced neutrophil migration.
Organylthio(silyl)carbenes
Authors: Wagner Tobias , Lange Jens , Grote Dirk , Sander Wolfram , Schaumann Ernst , Adiwidjaja Gunadi , Adam Arnold , Kopf Jürgen
Published: September 2009

The title carbenes 5 can be generated either from diazo compounds 9 by copper‐catalyzed catalysis or from chloro(organylthio)methylsilanes 12 by base‐induced α‐elimination. This is confirmed by [2+1] cycloadditions with alkenes to give the cyclopropanes 4a–d and 14. Product 4a is identical with the product obtained from carbanion 1c, phenyloxirane, and styrene, for which a carbene intermediate 5a had been invoked. On heating in the presence of copper triflate, cyclopropane 4a undergoes ring enlargement to the thiochroman 11. With (Z)‐ or (E)‐alkenes 20, carbene 5a gives stereospecific cyclopropane formation, although maleate turns out not to be a suitable indicator for a stereospecific cycloaddition. The suggested singlet character of 5 is confirmed by DFT calculations (B3LYP/cc‐pVTZ). The structures of cyclopropanes 4a and 23, as well as those of thiochroman 11 and carbene dimer 15, were confirmed by single‐crystal X‐ray investigations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Organocatalytic anti‐Selective Mannich Reactions with Fluorinated Aldimines: Synthesis of anti‐γ‐Fluoroalkyl‐γ‐amino Alcohols
Authors: Fustero Santos , Mojarrad Fatemeh , Carrión María Dolores Pérez , Sanz‐Cervera Juan F. , Aceña José Luis
Published: September 2009

The asymmetric Mannich reaction between fluoroalkyl aldimines and aldehydes catalyzed by α,α‐diphenylprolinol trimethylsilyl ether is reported. The corresponding Mannich adducts were reduced in situ to afford anti‐β‐alkyl‐γ‐fluoroalkyl‐γ‐amino alcohols in moderate yields and with very high diastereo‐ and enantioselectivities. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Small‐scale experimental simulation of talus evolution
Authors: De Blasio Fabio Vittorio , Sæter May‐Britt
Published: September 2009

We investigated a small‐scale laboratory model of a talus slope evolution. Five different size classes of basaltic rock were selected and marked with different colours. Homogenized mixtures of grains of different sizes were dropped from a fixed height onto a tilted experimental board covered with a loose granular layer. This was conducted in a series of regular sequences, and the resulting distribution on the board was studied after each sequence. At the beginning of the experiment, the grains developed a longitudinal gradation similar to natural talus slopes, where small grains settle at the top while the large ones roll down to the distal part. However, after a transient period dominated by single‐particle dynamics on the inert granular medium, the evolution proved to be more variable than expected. Due to the continuous shower of falling grains, the shear stress at the bottom of the upper granular layer increased. This resulted initially in a slow creep down slope that finally collapsed in large avalanches homogenizing the material. The slides occurred at the boundary between a weaker layer created by migration of small grains through the interstices, and marked by a vertical transition between small and large grains. We compare the experimental findings with observations from natural talus slopes, and suggest that similar experiments may be helpful in understanding the evolution of taluses. Copyright © 2009 John Wiley & Sons, Ltd.
Mouse Organic Solute Transporter α Deficiency Enhances Renal Excretion of Bile Acids and Attenuates Cholestasis
Authors: Soroka Carol J. , Mennone Albert , Hagey Lee R. , Ballatori Nazzareno , Boyer James L.
Published: September 2009

Organic solute transporter alpha-beta (Ostα-Ostβ) is a heteromeric bile acid and sterol transporter that facilitates the enterohepatic and renal-hepatic circulation of bile acids. Hepatic expression of this basolateral membrane protein is increased in cholestasis, presumably to facilitate removal of toxic bile acids from the liver. In this study, we show that the cholestatic phenotype induced by common bile duct ligation (BDL) is reduced in mice genetically deficient in

Ost

α. Although

Ost

α−/− mice have a smaller bile acid pool size, which could explain lower serum and hepatic levels of bile acids after BDL, gallbladder bilirubin and urinary bile acid concentrations were significantly greater in

Ost

α−/− BDL mice, suggesting additional alternative adaptive responses. Livers of

Ost

α−/− mice had higher messenger RNA levels of constitutive androstane receptor (Car) than wild-type BDL mice and increased expression of Phase I enzymes (

Cyp7a1

,

Cyp2b10

,

Cyp3a11

), Phase II enzymes (

Sult2a1

,

Ugt1a1

), and Phase III transporters (

Mrp2

,

Mrp3

). Following BDL, the bile acid pool size increased in

Ost

α−/− mice and protein levels for the hepatic basolateral membrane export transporters, multidrug resistance-associated protein 3 (Mrp3) and Mrp4, and for the apical bilirubin transporter, Mrp2, were all increased. In the kidney of

Ost

α−/− mice after BDL, the apical bile acid uptake transporter Asbt is further reduced, whereas the apical export transporters Mrp2 and Mrp4 are increased, resulting in a significant increase in urinary bile acid excretion.

Conclusion:

These findings indicate that loss of

Ost

α provides protection from liver injury in obstructive cholestasis through adaptive responses in both the kidney and liver that enhance clearance of bile acids into urine and through detoxification pathways most likely mediated by the nuclear receptor Car. (Hepatology 2010.)
Folding Defects in P-Type Atp 8B1 Associated With Hereditary Cholestasis Are Ameliorated by 4-Phenylbutyrate
Authors: van der Velden Lieke M. , Stapelbroek Janneke M. , Krieger Elmar , van den Berghe Peter V. E. , Berger Ruud , Verhulst Patricia M. , Holthuis Joost C. M. , Houwen Roderick H. J. , Klomp Leo W. J. , van de Graaf Stan F. J.
Published: September 2009

Deficiency in P-type ATP8B1 is a severe and clinically highly variable hereditary disorder that is primarily characterized by intrahepatic cholestasis. It presents either as a progressive (progressive familial intrahepatic cholestasis type 1 [PFIC1]) or intermittent (benign recurrent intrahepatic cholestasis type 1 [BRIC1]) disease. ATP8B1 deficiency is caused by autosomal recessive mutations in the gene encoding ATP8B1, a putative aminophospholipid-translocating P-type adenosine triphosphatase. The exact pathogenesis of the disease is elusive, and no effective pharmacological therapy is currently available. Here, the molecular consequences of six distinct

ATP8B1

missense mutations (p.L127P, p.G308V, p.D454G, p.D554N, p.I661T, and p.G1040R) and one nonsense mutation (p.R1164X) associated with PFIC1 and/or BRIC1 were systematically characterized. Except for the p.L127P mutation, all mutations resulted in markedly reduced ATP8B1 protein expression, whereas messenger RNA expression was unaffected. Five of seven mutations resulted in (partial) retention of ATP8B1 in the endoplasmic reticulum. Reduced protein expression was partially restored by culturing the cells at 30°C and by treatment with proteasomal inhibitors, indicating protein misfolding and subsequent proteosomal degradation. Protein misfolding was corroborated by predicting the consequences of most mutations onto a homology model of ATP8B1. Treatment with 4-phenylbutyrate, a clinically approved pharmacological chaperone, partially restored defects in expression and localization of ATP8B1 substitutions G308V, D454G, D554N, and in particular I661T, which is the most frequently identified mutation in BRIC1.

Conclusion:

A surprisingly large proportion of

ATP8B1

mutations resulted in aberrant folding and decreased expression at the plasma membrane. These effects were partially restored by treatment with 4-phenylbutyrate. We propose that treatment with pharmacological chaperones may represent an effective therapeutic strategy to ameliorate the recurrent attacks of cholestasis in patients with intermittent (BRIC1) disease. (Hepatology 2009.)
Long‐term rainfall monthly shortage in Spain: spatial patterns, statistical models and time trends
Authors: Martínez M. D. , Lana X. , Burgueño A.
Published: September 2009

Several patterns of the monthly rainfall shortage in Spain are investigated by using long‐term series of monthly rain amounts, which were recorded at 34 observatories and compiled by the Agencia Estatal de Meteorología, AEMET (Spanish Ministry of Environment). Owing to the strong variability of the pluviometric regime along the year, the median of the empirical monthly rain amounts is estimated for every month of the year. A monthly shortage is then defined as the difference between the corresponding monthly median and the monthly rain amount. A spell of monthly shortage is a set of consecutive months with amounts below the corresponding monthly medians. Five magnitudes are defined to characterize the rainfall shortage: (1) the spell length, L (months); (2) the average monthly shortage of a spell, < S > (mm); (3) the largest monthly shortage in a spell, SM (mm); (4) the total rainfall shortage for every spell, CS (mm) and (5) the rainfall amount for every shortage spell, CR. The whole number of spells, N, and the number of spells as a function of shortage lengths, N(L), are compared with those deduced from the distribution theory of runs (TR). Instead of a geometric distribution, a Markov chain of first order with two states becomes a better option for the probability density function of L. Although the empirical distributions of < S > , SM and CS are well fitted by a Pearson‐type III model for most gauges, the generalized Pareto (GP) distribution is sometimes a better choice. The distribution of CR is well fitted by gamma and especially Poisson‐gamma models. Besides these statistical analyses, an interpretation of the rainfall shortage is attempted by looking for links between the distributions of cumulative monthly shortage (CMS), and cumulative number of months (CNM) with rainfall deficit. Both distributions generate normalized shortage curves (NSC), which follow similar laws to the normalized rainfall curves (NRC), used, for instance, in the study of daily rainfall amounts. Finally, statistical significance of local and field time trends of < S > , SM and CS are evaluated. Copyright © 2009 Royal Meteorological Society
Reductosols: Natural soils and Technosols under reducing conditions without an aquic moisture regime
Authors: Blume Hans‐Peter , Felix‐Henningsen Peter
Published: September 2009

According to the German soil classification, Reductosols (German: “Reduktosole”) are soils with a redoximorphic color pattern, but without water saturation for lengthy periods. They are formed by reducing conditions due to oxygen deficiency caused by the accumulation of reduct gases such as CH4, CO2, NH3, or H2S in the soil atmosphere. Soil oxygen may have been displaced by the ascent of CO2 from post‐volcanic mofettes or by CH4 from sanitary landfills. Furthermore, a lack of oxygen causing redoximorphism can occur in unsaturated soils if they contain or receive large quantities of easily decomposable organic matter (i.e., organic urban waste or sludge). Under such circumstances, a gleyic color pattern (e.g., an oxidized Bg horizon above a Cr horizon with strongly reducing conditions) forms without the influence of an aquic moisture regime. Waste‐water and petrol infiltration in soil can form a stagnic color pattern without the stagnation of surface water. Such more or less well‐drained but strongly redoximorphic horizons should be named as Yg instead of Bg.

In some cases, such soils only exist for a short time due to the loss of reduct gases or termination of infiltration of organic liquids. Reductosols are ecotops with oxygen deficiency. Natural Reductosols dominate in recent and former volcanic areas, whereas Reductic Technosols are formed in urban‐industrial agglomerations. Their morphology, chemistry, dynamics, genesis, and ecology is summarized and discussed in this paper.

Natural gas and CO2 gas are deposited in deeper zones of the earth crust since some time. Leakages of these depots let form reductosols as well.
Genotypic variation of potato for phosphorus efficiency and quantification of phosphorus uptake with respect to root characteristics
Authors: Balemi Tesfaye , Schenk Manfred K.
Published: September 2009

Potato (Solanum tuberosum L.), an important food crop, generally requires a high amount of phosphate fertilizer for optimum growth and yield. One option to reduce the need of fertilizer is the use of P‐efficient genotypes. Two efficient and two inefficient genotypes were investigated for P‐efficiency mechanisms. The contribution of root traits to P uptake was quantified using a mechanistic simulation model.

For all genotypes, high P supply increased the relative growth rate of shoot, shoot P concentration, and P‐uptake rate of roots but decreased root‐to‐shoot ratio, root‐hair length, and P‐utilization efficiency. Genotypes CGN 17903 and CIP 384321.3 were clearly superior to genotypes CGN 22367 and CGN 18233 in terms of shoot–dry matter yield and relative shoot‐growth rate at low P supply, and therefore can be considered as P‐efficient. Phosphorus efficiency of genotype CGN 17903 was related to higher P‐utilization efficiency and that of CIP 384321.3 to both higher P‐uptake efficiency in terms of root‐to‐shoot ratio and intermediate P‐utilization efficiency. Phosphorus‐efficient genotypes exhibited longer root hairs compared to inefficient genotypes at both P levels. However, this did not significantly affect the uptake rate and the extension of the depletion zone around roots. The P inefficiency of CGN 18233 was related to low P‐utilization efficiency and that of CGN 22367 to a combination of low P uptake and intermediate P‐utilization efficiency. Simulation of P uptake revealed that no other P‐mobilization mechanism was involved since predicted uptake approximated observed uptake indicating that the processes involved in P transport and morphological root characterstics affecting P uptake are well described.
Hereditary parkinsonism: Parkinson disease look‐alikes—An algorithm for clinicians to “PARK” genes and beyond
Authors: Klein Christine , Schneider Susanne A. , Lang Anthony E.
Published: September 2009

In the past decade, a number of genetic causes of parkinsonism have been identified. As a consequence, clinicians have to consider an increasing range of differential diagnoses when confronted with a patient with parkinsonism with a positive family history. While well‐established monogenic forms with PARK acronyms have been reviewed extensively, less emphasis has been placed on other inherited conditions that may also present with signs of parkinsonism or even mimic idiopathic Parkinson's disease clinically. In this review, we focus on three different scenarios in patients with an overall early age of onset of parkinsonism: (i) atypical features in patients with mutations in one of the “PARK” genes; (ii) classical parkinsonism due to mutations in “other than‐PARK” genes or yet other genes where parkinsonism may be a well‐recognized, concomitant, or even an isolated feature; (iii) atypical parkinsonism in other genetic disorders which are, however, typically characterized by features other than parkinsonism. Atypical features in patients from Group I include, for example, a slower disease course (PARK2, PARK6, PARK7) or dementia (PARK1/4, PARK14). Conditions in Group II have been designated by a DYT or SCA acronym (for example, DYT5 or SCA3) and also include patients with heterozygous GBA mutations, mitochondrial gene mutations. Group III comprises mutations in the FMR1, MAPT, GRN, ATP7B, PANK2, FBXO7, CHAC, FTL1, Huntingtin, JPH3 genes, and a number of even rarer, miscellaneous conditions. © 2009 Movement Disorder Society
Neuropathology of Parkinson's disease with the R1441G mutation in LRRK2
Authors: Martí‐Massó José‐Félix , Ruiz‐Martínez Javier , Bolaño Maria J. , Ruiz Irune , Gorostidi Ana , Moreno Fermin , Ferrer Isidre , de Munain Adolfo López
Published: September 2009

We report the neuropathological findings in a patient with Parkinson's disease (PD) associated with Basque R1441G‐LRRK2/dardarin mutation. The patient was a man with disease onset at 68 years of age, with unilateral rest tremor; the Parkinsonism was well controlled with medication for 15 years. He died at the age of 86, after 18 years of evolution. The neuropathological examination disclosed mild neuronal loss in the substantia nigra pars compacta without α‐synuclein, tau, LRRK2, or ubiquitin cytoplasmic inclusions. Lewy bodies and Lewy neurites were absent. This is the first neuropathological study of PD associated with brain with the R1441G mutation in LRRK2. © 2009 Movement Disorder Society
Relative preservation of thalamic centromedian nucleus in parkinsonian patients with dystonia
Authors: Truong Linda , Brooks Daniel , Amaral Fabricio , Henderson Jasmine M. , Halliday Glenda M.
Published: September 2009

To determine whether variable thalamic degeneration in Parkinson's disease (PD) contributes to less drug responsive clinical features. Formalin‐fixed thalami from longitudinally followed patients with PD and early dystonia (N = 6), early falls (N = 5) or no dystonia or falls (N = 6) and age‐matched controls without neuropathology (N = 10) were serially sectioned, stained, and analyzed. Neurons in the centromedian parafascicular (CM‐Pf) nucleus were quantified using the optical disector method and analysis of variance with post hoc testing used to determine variability in neurodegeneration between groups. Patients with PD were confirmed to have significant neurodegeneration in the CM‐Pf complex, with no difference in the degree of neurodegeneration between patients with PD with early falls compared with patients with no history of falls or dystonia. In contrast, patients with PD with early dystonia had significantly less neurodegeneration of the CM but not the Pf than patients without this feature. Preservation of the CM in patients with PD with early dystonia would result in a relative increase in CM activity through the direct basal ganglia pathway and increased primary motor cortex activity. Overall this data provides evidence for pathway‐specific neurodegeneration as an underlying feature of the clinical variability observed in patients with PD. © 2009 Movement Disorder Society
Extrapyramidal stiffness in patients with amyotrophic lateral sclerosis
Authors: Pradat Pierre‐François , Bruneteau Gaelle , Munerati Elisabetta , Salachas François , Le Forestier Nadine , Lacomblez Lucette , Lenglet Timothee , Meininger Vincent
Published: September 2009

There is accumulating evidence that ALS is a multisystem degenerative disease, raising the question of whether some symptoms are of extrapyramidal origin. The objective was to better characterize the type of stiffness in a series of ALS patients and to study correlations with balance and postural impairment. We studied ALS patients who exhibited stiffness without noticeable motor deficit in the lower limbs. We analyzed the response to manual stretch velocity to differentiate between extrapyramidal (rigidity) or pyramidal (spasticity) stiffness, shortening reaction in the tibialis anterior muscles (abolished in pyramidal diseases and exaggerated in extrapyramidal diseases) and balance and posture impairment (UPDRS and Berg's scale). After a preliminary inter‐rater reliability study, 39 consecutive ALS patients were prospectively recruited. Each patient was randomly assigned to one or other of two investigators who evaluated either stiffness or balance impairment. In the lower limbs, rigidity was observed in at least one muscle in 27/39 patients (69%), and shortening reaction was exaggerated in 20/39 patients (51%). Both were correlated with balance and posture impairment (UPDRS and Berg's scale,P< 0.001). This study suggests that extrapyramidal involvement plays a role in stiffness and balance impairment in a subset of ALS patients. © 2009 Movement Disorder Society
Global existence to a reaction–diffusion equation through a self‐similar‐like upper solution
Authors: Bernard Guy
Published: September 2009

A demonstration method is presented, which will ensure the existence of positive global solutions in time to the reaction–diffusion equation −ut+Δu+up=0 in ℝn×[0, ∞), for exponents p⩾3 and space dimensions n⩾3. This method does not require the initial value to have a specific uniform smallness condition, but rather to satisfy a bell‐like form. The method is based on a specific upper solution, which models the diffusion process of the heat equation. The upper solution is not self‐similar, but does have a self‐similar‐like form. After transforming the reaction–diffusion problem into an equivalent one, whose initial value is uniformly very small, a local solution is obtained in the time interval [0, 1] by the use of this upper solution. This local solution is then extended to [0, ∞) through an infinite sequence of extensions. At each step, an appropriate change of variables will transform the extension into a problem nearly identical to the local problem in [0, 1]. These transformations exploit the diffusive and self‐similar‐like nature of the upper solution. Copyright
© 2009 John Wiley & Sons, Ltd.
Wave propagation in an inhomogeneous cross‐anisotropic medium
Authors: Wang Cheng‐Der , Lin Ya‐Ting , Jeng Yu‐Shiuh , Ruan Zheng‐Wei
Published: September 2009

Analytical solutions for wave velocities and wave vectors are yielded for a continuously inhomogeneous cross‐anisotropic medium, in which Young's moduli (E, E′) and shear modulus (G′) varied exponentially as depth increased. However, for the rest moduli in cross‐anisotropic materials, ν and ν′ remained constant regardless of depth. We assume that cross‐anisotropy planes are parallel to the horizontal surface. The generalized Hooke's law, strain–displacement relationships, and equilibrium equations are integrated to constitute governing equations. In these equations, displacement components are fundamental variables and, hence, the solutions of three quasi‐wave velocities, VP, VSV, and VSH, and the wave vectors, \documentclass{article}\usepackage{amssymb}\usepackage{amsbsy}\usepackage[mathscr]{euscript}\footskip=0pc\pagestyle{empty}\begin{document}$\mathop{\mathop{l}\limits^{\rightharpoonup}}\nolimits_{P}$\end{document} \documentclass{article}\usepackage{amssymb}\usepackage{amsbsy}\usepackage[mathscr]{euscript}\footskip=0pc\pagestyle{empty}\begin{document}$\mathop{\mathop{l}\limits^{\rightharpoonup}}\nolimits_{\mathit{SV}}$\end{document}, and \documentclass{article}\usepackage{amssymb}\usepackage{amsbsy}\usepackage[mathscr]{euscript}\footskip=0pc\pagestyle{empty}\begin{document}$\mathop{\mathop{l}\limits^{\rightharpoonup}}\nolimits_{{\mathit{SH}}}$\end{document}, can be generated for the inhomogeneous cross‐anisotropic media. The proposed solutions and those obtained by Daley and Hron, and Levin correlate well with each other when the inhomogeneity parameter, k, is 0. Additionally, parametric study results indicate that the magnitudes and directions of wave velocity are markedly affected by (1) the inhomogeneous parameter, k; (2) the type and degree of geomaterial anisotropy (E/E′, G′/E′, and ν/ν′); and (3) the phase angle, θ. Consequently, one must consider the influence of inhomogeneous characteristic when investigating the behaviors of wave propagation in a cross‐anisotropic medium. Copyright © 2009 John Wiley & Sons, Ltd.
Improved explicit integration in plasticity
Authors: Vrh Marko , Halilovič Miroslav , Štok Boris
Published: September 2009

The article presents a simple but efficient numerical scheme for the integration of non‐linear constitutive equations, in which the principal reason for the inaccuracy of the classical explicit schemes, for example forward‐Euler scheme, is effectively eliminated. In the newly developed explicit scheme, where there is no need for iteration, the implementation simplicity of the forward‐Euler scheme and accuracy of the approach, which is using the backward‐Euler scheme to integrate the constitutive equations, are successfully combined. Computational performance of the proposed next increment corrects error (NICE) integration scheme, particularly regarding the accuracy and the CPU time consumption, is first analysed on a case of complex loading of a material point. When comparing it to the forward‐Euler, backward‐Euler, trapezoidal and midpoint integration schemes, it turns out that because of its capability of a fast and relatively accurate integration of the constitutive equations, the NICE scheme is very convenient for the integration of constitutive models, where a direct solution technique is used to solve a boundary value problem. Although the deduction of the new integration scheme is general, its implementation for shell applications needs particular care. Namely, in order to satisfy the zero normal stress condition during the whole integration, a through‐thickness strain increment has to be adequately chosen in each integration step. The NICE scheme, which was also implemented into ABAQUS/Explicit via User Material Subroutine (VUMAT) interface platform, has been additionally compared with the ABAQUS/Explicit default integration scheme (backward‐Euler) and forward‐Euler scheme. Two loading case‐studies, namely the bending of a square plate and the stretching of a specimen including the onset of necking, are considered with two constitutive models—the von Mises and GTN material model being adopted. Generally, the NICE scheme has demonstrated to be advantageous in cases, where reasonable accuracy and very fast integration of the constitutive model is demanded, which is mostly the case in engineering computations with a direct solution method, for example explicit dynamics and metal forming process simulations. Copyright © 2009 John Wiley & Sons, Ltd.
The interaction of Bacillus subtilis σA with RNA polymerase
Authors: Johnston Elecia B. , Lewis Peter J. , Griffith Renate
Published: September 2009

RNA polymerase (RNAP) is an essential and highly conserved enzyme in all organisms. The process of transcription initiation is fundamentally different between prokaryotes and eukaryotes. In prokaryotes, initiation is regulated by σ factors, making the essential interaction between σ factors and RNAP an attractive target for antimicrobial agents. Our objective was to achieve the first step in the process of developing novel antimicrobial agents, namely to prove experimentally that the interaction between a bacterial RNAP and an essential σ factor can be disrupted by introducing carefully designed mutations into σA of Bacillus subtilis. This disruption was demonstrated qualitatively by Far‐Western blotting. Design of mutant σs was achieved by computer‐aided visualization of the RNAP‐σ interface of the B. subtilis holoenzyme (RNAP + σ) constructed using a homology modeling approach with published crystal structures of bacterial RNAPs. Models of the holoenzyme and the core RNAP were rigorously built, evaluated, and validated. To allow a high‐quality RNAP‐σ interface model to be constructed for the design of mutations, a crucial error in the B. subtilis σA sequence in published databases at amino acid 165 had to be corrected first. The new model was validated through determination of RNAP‐σ interactions using targeted mutations.
Effect of different modified atmosphere packaging on microbial quality, oxidation and colour of a seasoned ground beef product (meatball)
Authors: Ozturk Aylin , Yilmaz Neriman , Gunes Gurbuz
Published: September 2009

The effects of different modified atmosphere packaging (MAP) on microbial quality, oxidation and colour of meatballs were investigated. Meatballs were prepared in our laboratory and packaged in vacuum or in different gases: combinations of O2 (0, 2, 21%) and CO2 (0, 33, 66, 100%) with N2 as balance gas. Total microbial count, thiobarbituric acid reactive substances and colour were determined during storage at 3°C for 3 weeks. Total microbial count remained unchanged at around 6.3 LogCFU/g in vacuum and 100% CO2 packages after 7 days, and slightly increased afterwards. The microbial count was higher in other packages and increased to 7.6 LogCFU/g after 21 days storage. Oxidation was inhibited by reduced O2 and increased CO2 in the packages. Packages with low O2 maintained colour (a‐values) to a greater extent than the packages with higher O2 levels. MAP containing 1–3%O2 with 33%CO2 inhibited microbial growth, oxidation and colour change in meatballs. Copyright © 2009 John Wiley & Sons, Ltd.
A note on the power prior
Authors: Neuenschwander Beat , Branson Michael , Spiegelhalter David J.
Published: September 2009

The power prior by Ibrahim and Chen (Statist. Sci. 2000; 15:46–60) is one of several methods to incorporate historical data in the analysis of a clinical trial. The power prior raises the likelihood of the historical data to the power parameter a0 which quantifies the discounting of the historical data due to heterogeneity between trials. It is shown that the standard method of estimating the power parameter from the historical and current data is inappropriate, and we therefore suggest to use a modified power prior approach or to consider alternative methods instead. Copyright © 2009 John Wiley & Sons, Ltd.
High‐pressure Phase Transition and Properties of Cu3N: An Experimental and Theoretical Study
Authors: Wosylus Aron , Schwarz Ulrich , Akselrud Lev , Tucker Matt G. , Hanfland Michael , Rabia Kaneez , Kuntscher Christine , von Appen Jörg , Dronskowski Richard , Rau Dieter , Niewa Rainer
Published: September 2009

In‐situ X‐ray and neutron diffraction investigations on Cu3N indicate the onset of a high‐pressure phase transition at about 5 GPa. The tetragonal cell parameters of the high‐pressure phase reveal a discontinuous volume decrease of about 20 %. The phase transition is reversible, with a hysteresis of about 2 GPa. Subsequent ex‐situ investigations in a multi‐anvil press evidence a reversible re‐formation of ambient pressure Cu3N from XRD patterns. The structure refinement with nitrogen atoms disordered in distorted octahedral voids of a tetragonal body‐centered copper substructure leads to an occupation of approximately 1/3 and thus to a composition of Cu3N1.0(1). Optical absorption measurements (IR‐VIS) up to 10 GPa indicate a semiconductor–metal transition. Density‐functional based total energy calculations concerning the proposed high‐pressure phase of Cu3N strongly support the experimental findings of a pressure‐induced phase transition above 6 GPa to a structure with a copper tetragonal body‐centered sublattice and nitrogen atoms in distorted octahedral voids. However, the calculations identify a need for an ordered alternative to provide the tetragonal distortion within the range of the observed c/a ratio. The resulting lattice parameters and the transition pressure fit with the measured data. For the case of an ordered occupation of the copper bct octahedral voids, all observed properties are in good agreement with the calculations.
An Automated Micropositioning System for Investigating C. Elegans Locomotive Behavior
Authors: Wang Wenhui , Sun Yu , Dixon Scott J. , Alexander Mariam , Roy Peter J.
Published: September 2009

This paper presents a visually servoed micropositioning system capable of automatically extracting locomotive features of Caenorhabditis elegans online at a full 30 Hz. The employment of Gaussian Pyramid Level-2 images significantly reduces the image size by 16-fold and permits real-time feature extraction, without sacrificing accuracy due to the cubic smoothing spline fitting. The automated micropositioning system is capable of revealing subtle differences in locomotive behavior across strains. A total of 128 worms of four C. elegans strains with different numbers of muscle arms were continuously tracked for 3 min per sample, and locomotive features were extracted online. Validated by experiments, the innovation in image analysis, or data reduction without sacrificing accuracy allows for rapid, online, and accurate analysis of streaming videos of C. elegans and other similar microorganisms.
In Situ Nanoliter-Scale Polymer Fabrication for Flexible Cell Patterning
Authors: Liberski Albert R. , Zhang Rong , Bradley Mark
Published: September 2009

Drug-testing technologies, biosensor fabrication, tissue engineering, and basic biological research depend strongly on the patterning of live animal cells. Current techniques for controlling cellular adhesion are restricted with two primary limitations. Firstly, the complexity of the available patterns is very limited and, secondly, the pallet of materials that induce cellular patterning is exhaustible. Here, we demonstrate a method for computer-aided control of cell patterning using a scientific inkjet printer that yields a highly complex cellular pattern suitable for applications in regenerative medicine and rapid prototyping, and a strategy for using in situ polymerization for fabrication polymeric patterns directly on-chip.
2008 ALA Survey on Laboratory Automation
Authors: Hamilton Steven D.
Published: September 2009

This JALA feature story reports the results of two surveys conducted by the Association for Laboratory Automation (ALA) to evaluate the state of industrial laboratory automation. The purpose was to gain more insight into the results of the 2006 ALA survey by posing more detailed questions based on the 2006 responses. The 2008 survey polled 43 carefully selected ALA members whose organizations use laboratory automation. These organizations represented the biotech, pharmaceutical, agricultural science, consumer goods, materials and formulation, research institute, and government business sectors. The 2008 survey also polled 12 leading laboratory automation technology providers. Questions were designed to compare the trends, needs, and priorities of the user and provider communities.
A Flow-Through Ultrasonic Lysis Module for the Disruption of Bacterial Spores
Authors: Warner Cynthia L. , Bruckner-Lea Cynthia J. , Grate Jay W. , Straub Timothy , Posakony Gerald J. , Valentine Nancy , Ozanich Richard , Bond Leonard J. , Matzke Melissa M. , Dockendorff Brian , Valdez Catherine , Valdez Patrick , Owsley Stanley
Published: September 2009

An automated, flow-through ultrasonic lysis module that is capable of disrupting bacterial spores to increase the DNA available for biodetection is described. The system uses a flow-through chamber that allows for direct injection of the sample without the need for a chemical or enzymatic pretreatment step to disrupt the spore coat before lysis. Lysis of Bacillus subtilis spores, a benign simulant of Bacillus anthracis, is achieved by flowing the sample through a tube whose axis is parallel to the faces of two transducers that deliver 10 W cm−2 to the surface of the tube at 1.4-MHz frequency. Increases in amplifiable DNA were assessed by real-time PCR analysis that showed at least a 25-fold increase in amplifiable DNA after ultrasonic treatment with glass beads, compared with controls with no ultrasonic power applied. The ultrasonic system and integrated fluidics are designed as a module that could be incorporated into multistep, automated sample treatment and detection systems for pathogens.
High-Throughput Screening for High Affinity Antibodies
Authors: Tickle Simon , Adams Ralph , Brown Derek , Griffiths Meryn , Lightwood Daniel , Lawson Alastair
Published: September 2009

UCB Selected Lymphocyte Antibody Method (SLAM) is a rapid and efficient process for the generation of high-quality monoclonal antibodies, in which variable region gene sequences are recovered directly from specific, single B cells. Monoclonal antibody generation has been limited in the past by the relatively low efficiency of the hybridoma process. UCB SLAM process is well suited to high-throughput screening and has been extensively automated at UCB. If necessary, in excess of 1 times 10 9 B cells can be screened in a campaign, to discover a rare therapeutic antibody candidate, which meets the stringent selection criteria. Primary screening for antigen binders, on purified or cell expressed antigen, is performed using a homogeneous fluorescence assay format. Supernatants from positive wells are consolidated to allow further secondary screening and selection of antibodies with desired characteristics. Individual, specific B cells are identified using a fluorescence based method and isolated using a micromanipulator. The antibody variable region genes are cloned from DNA extracted from the single B cell. The genes are sequenced then prepared for transient expression to confirm activity. Antibodies with affinities ( KD) in the sub 10 pM range against a range of therapeutic targets are routinely recovered using this process.
Process Evaluation of a Fully Automated Molecular Diagnostics System
Authors: Felder Robin A. , Foster Maria L. , Lizzi Michael J. , Pohl Brent R. , Diemert Dustin M. , Towns Bryan G.
Published: September 2009

Molecular diagnostics presents challenges to clinical laboratories that are under pressure to consolidate and automate. There is a need to evaluate molecular automation for process efficiency and suitability for high-throughput environments in core laboratories.

A fully automated molecular instrument platform (the BD Viper System with XTR Technology in extracted mode [BD Viper System with XTR]), was evaluated for automation efficiency, labor requirements, and system robustness. System productivity was predicted using time and motion studies as well as process simulation.

Preanalytical steps required 15 min of skilled operator time. The BD Viper System with XTR fully automated DNA extraction, amplification, and analysis of 368 specimens (736 results for Chlamydia and Gonorrhea). Time and motion studies estimated that the total hands-on full time employee (FTE) burden was approximately 35 min per run, of which 41% was high complexity, 29% medium complexity and 29% relatively unskilled labor. A skilled operator can easily operate four instruments for 8.5 h and generate data on 2944 results (four runs on each instrument for a total of 1472 clinical specimens) for Chlamydia trachomatis (CT) and Neisseria gonorrhoeae (GC) analysis. Based on mean time between intervention data, the BD Viper System with XTR was estimated to be capable of operating for more than 1000 runs without system malfunction.

We determined that fully automated molecular analysis of GC and CT is possible in a core laboratory facility with significant throughput and minimal impact on labor demand using a fully automated and robust molecular diagnostics platform (such as the BD Viper System with XTR).
Effect of seaweed and cholesterol-enriched diets on postprandial lipoproteinaemia in rats
Authors: Bocanegra Aránzazu , Bastida Sara , Benedí Juana , Nus Meritxell , Sánchez-Montero Jose M. , Sánchez-Muniz Francisco J.
Published: September 2009

High postprandial lipaemia increases cardiovascular risk. Algae consumption may affect postprandial lipoproteinaemia. The effects of dietary alga and cholesterol supplementation on postprandial lipaemia and lipoproteinaemia and arylesterase (AE) activity in growing male Wistar rats were tested in the present study. Six groups of ten rats were fed a casein-based diet for 3 weeks. Three of the diets contained 2·4 % cholesterol-raising agent (Chol), while the other three did not (NChol). Seven percentage of the control diets (NChol-C and Chol-C) consisted of a cellulose–wheat starch mix (35:65), while the Nori alga diets (NChol-N and Chol-N) and Konbu diets (NChol-K and Chol-K) contained 7 % of each respective freeze-dried alga. Postprandial plasma was obtained after a 3 h diet withdrawal. Supplementary cholesterol and alga type significantly affected (at leastP < 0·05) the cholesterol, TAG, phospholipid and protein contents of the various lipoprotein fractions. AE enzyme activity increased (P < 0·05) in NChol rats given Nori and Konbu diets. NChol-K, but not NChol-N, rats displayed higher (P < 0·05) plasma cholesterol, TAG and phospholipid levels than NChol-C animals. NChol-K rats presented higher TAG, phospholipid, protein and lipoprotein mass values than their NChol-C counterparts. Inclusion of algae in Chol diets decreased (P < 0·001) the postprandial hypertriacylglycerolaemia. The Chol-N diet affected most lipoprotein fraction contents. Chol-N rats had lower postprandial cholesterolaemia and a better lipoprotein profile (fewer LDL and a tendency toward more HDL and fewer cholesterol-enriched VLDL) than Chol-K rats, suggesting that Nori is the alga of choice in dietary treatment of hypercholesterolaemia.