bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical transmission electron microscopy and electron diffraction for characterization of multiphase Ni‐P‐Ti surface layer on Ti‐6Al‐4V alloy
Authors: CZYRSKA‐FILEMONOWICZ A. , BUFFAT P. A.
Published: November 2006

The microstructure, chemical and phase composition of the hard Ni‐P‐Ti layer formed on the Ti‐6Al‐4V alloy after duplex surface treatment were investigated by light microscopy, X‐ray diffraction, scanning electron microscopy and analytical/high‐resolution transmission electron microscopy. These investigations showed that the improved mechanical and tribological properties of the surface‐treated alloy were related to the presence of a multilayered microstructure containing several phases from the Ni‐Ti‐P‐Al system.
Microstructure evolution in age‐hardenable aluminium alloy during processing by hydrostatic extrusion
Authors: LEWANDOWSKA M.
Published: November 2006

In the present work, scanning and transmission electron microscopy were used to investigate the microstructural evolution occurring during the hydrostatic extrusion of an age‐hardenable aluminium alloy. It was shown that processing by hydrostatic extrusion leads to grain refinement to 95 nm in equivalent diameter. Hydrostatic extrusion also influences the geometrical parameters of two different types of particle: intermetallic inclusions and precipitates. The intermetallic inclusions slightly decrease in mean equivalent diameter, but their size remains at the micrometre level. The precipitates are fragmented to nanoscale spherical particles, and their evolution delays the process of grain refinement.
Transmission electron microscopy characterization of the erbium silicide formation process using a Pt/Er stack on a silicon‐on‐insulator substrate
Authors: ŁASZCZ A. , KĄTCKI J. , RATAJCZAK J. , TANG XIAOHUI , DUBOIS E.
Published: November 2006

Very thin erbium silicide layers have been used as source and drain contacts to n‐type Si in low Schottky barrier MOSFETs on silicon‐on‐insulator substrates. Erbium silicide is formed by a solid‐state reaction between the metal and silicon during annealing. The influence of annealing temperature (450 °C, 525 °C and 600 °C) on the formation of an erbium silicide layer in the Pt/Er/Si/SiO2/Si structure was analysed by means of cross‐sectional transmission electron microscopy. The Si grains/interlayer formed at the interface and the presence of Si grains within the Er‐related layer constitute proof that Si reacts with Er in the presence of a Pt top layer in the temperature range 450–600 °C. The process of silicide formation in the Pt/Er/Si structure differs from that in the Er/Si structure. At 600 °C, the Pt top layer vanishes and a (Pt–Er)Six system is formed.
Structure and properties of an alumina/amorphous‐alumina/platinum catalytic system deposited on FeCrAl steel
Authors: RESZKA K. , MORGIEL J. , RESZKA J.
Published: November 2006

We have investigated the properties and structure of alumina films obtained as a result of thermal oxidation of 0H18J5 steel under a mixture of SO2 and O2 atmosphere and then covered with layers of magnetron‐sputtered alumina and platinum. The catalytic tests and transmission electron microscopy investigations reveal that θ‐Al2O3 films containing acidic and basic sites are distinguished by high catalytic activity, whereas amorphous and α‐Al2O3 films show neutral activity. The platinum films deposited on them contribute to the enrichment of the laminar system with basic sites, and consequently raise the catalytic activity of the system. The investigations performed indicate that the catalytic activity of the system may be tailored to the desired level by the control of the thickness of the individual layers of coating.
Wavelength‐ and energy‐dispersive Electron Probe Microanalysis (EPMA) measurements with non‐perpendicular incidence of the electron beam
Authors: BASTIN G. F. , OBERNDORFF P. J. T. L. , HEIJLIGERS H. J. M. , DIJKSTRA J. M.
Published: November 2006

A database of 416 wavelength‐ and energy‐dispersive EPMA measurements on tilted specimens of NiAl, TiO2 and Ti3Al is presented. The analyses were performed between 10 and 30 kV and the tilt angles were varied between 0° and 60° in seven steps. The necessary hardware modifications for the specimen holder are discussed, as well as the various focusing techniques used in the measurements. A comparison between the experimental data, the calculations of our proza96t program and the results of Monte Carlo simulations shows that up to 50° tilt the predictions of our software are more than satisfactory. At larger tilt angles some deviations become noticeable. The Monte Carlo simulations appear to produce deviations at a somewhat earlier stage already, for reasons as yet unknown.
Scanning and transmission electron microscopy microstructure characterization of mechanically alloyed Nb–Ti–Al alloys
Authors: ROZMUS MAGDALENA , BLICHARSKI MAREK , DYMEK STANISŁAW
Published: November 2006

Results are presented of an investigation of the microstructure development during mechanical alloying and following consolidation of an Nb15Ti15Al alloy. The alloy was synthesized from elemental as well as pre‐alloyed powders. The microstructure of this material was examined by transmission electron microscopy, scanning electron microscopy and X‐ray diffraction. The use of pre‐alloyed TiAl powder for synthesis of the Nb15Ti15Al alloy meant that a much shorter time was required to complete the mechanical alloying process compared with the synthesis of elemental powders. The investigation indicates that three phases were present in the consolidated materials: the Nb solid solution, the Nb3Al intermetallic phase and the dispersoid.
Scanning electron microscopy and transmission electron microscopy microstructural investigation of high‐speed tool steel after Nd:YAG pulsed laser melting
Authors: KAC S. , KUSINSKI J. , ZIELINSKALIPIEC A. , WRONSKA I.
Published: November 2006

This article presents the microstructure of a pulsed Nd:YAG laser‐melted high‐speed steel, namely HS6‐5‐2. The high chemical homogeneity and fine structure of the melted zone was attributed to high cooling rates due to the short duration of interaction with the Nd:YAG pulsed laser radiation and the relatively small volume of the melted material. The structure obtained in the surface layer after laser melting has a high level of hardness and shows improved wear resistance.
Cathodoluminescence in transmission electron microscopy
Authors: STRUNK H. P. , ALBRECHT M. , SCHEEL H.
Published: November 2006

We describe a cathodoluminescence spectrometer that is attached to an analytical transmission electron microscope. After a brief consideration of the set‐up and the peculiarities of recording spectra and of mapping defect distributions in panchromatic and monochromatic cathodoluminescence, we discuss two examples of applications. Emphasis is placed on the potential for obtaining novel information about materials and processes on a microscopic and a nanoscopic scale by combining cathodoluminescence with the structural and chemical information for the same site of the specimen. We select an example concerning the role of In distribution in light emission from InGa/GaN quantum wells and a second one concerning the analysis of the initial electron radiation damage of Cu(In,Ga)Se2 photovoltaic films.
In situelectron beam induced current measurements of the local thickness in semiconductor devices
Authors: CZERWINSKI A. , PŁUSKA M. , RATAJCZAK J. , KATCKI J.
Published: November 2006

A quantitative electron beam induced current method is shown, applicablein situfor electron beam current measurement on a semiconductor sample without the need for a Faraday cup. As a validation technique, the measurement of top overlayer thickness in the semiconductor structure was chosen for two reasons. First, the measured thickness is easily verified using the same electron microscope in the secondary electron mode by measuring the layer thickness at the layer edges. Second, the measurement of a layer thickness and its local variations constitute an important issue in semiconductor processing and characterization. The proposed method is used in the planar view of the sample, and also for locations far from the layer edges. Quasi‐three‐dimensional maps of the thickness spatial distribution are presented.
Elimination of scanning electron microscopy image periodic distortions with digital signal‐processing methods
Authors: PŁUSKA M. , CZERWINSKI A. , RATAJCZAK J. , KĄTCKI J. , RAK R.
Published: November 2006

Electromagnetic interference is one of the main distortion sources in scanning electron microscopy. Electromagnetic interference‐generated scanning electron microscopy image distortions are usually visible as edge blur (at low scan rates) or vibration (at high scan rates). Hardware solutions to this problem, e.g. electrostatic and magnetic shielding, are expensive and, in some cases, difficult to implement. The current investigations led to a significant decrease in the periodic distortions by a novel adaptation of software‐based digital signal processing to scanning electron microscopy problems, without any hardware modification.
Buried amorphous‐layer impact on dislocation densities in silicon
Authors: WZOREK M. , KĄTCKI J. , PŁUSKA M. , RATAJCZAK J. , JAROSZEWICZ B. , DOMAŃSKI K. , GRABIEC P.
Published: November 2006

The impact of amorphous layers on dislocation densities in silicon piezoresistors was investigated by means of transmission electron microscopy and chemical etching. Mechanical bevel polishing at a shallow angle and selective etching were applied to assess the dislocation depth distributions. It was found that, despite the presence of additional defects after recrystallization, the initial presence of a buried amorphous layer reduced, after annealing, the dislocation density in the depletion region of a p–n junction, compared with the case of a shallower, surface amorphous layer.
Wing scale microstructures and nanostructures in butterflies − natural photonic crystals
Authors: VÉRTESY Z. , BÁLINT Zs. , KERTÉSZ K. , VIGNERON J. P. , LOUSSE V. , BIRÓ L. P.
Published: November 2006

The aim of our study was to investigate the correlation between structural colour and scale morphology in butterflies. Detailed correlations between blue colour and structure were investigated in three lycaenid subfamilies, which represent a monophylum in the butterfly family Lycaenidae (Lepidoptera): the Coppers (Lycaeninae), the Hairstreaks (Theclinae) and the Blues (Polyommatinae). Complex investigations such as spectral measurements and characterization by means of light microscopy, scanning electron microscopy and transmission electron microscopy enabled us to demonstrate that: (i) a wide array of nanostructures generate blue colours; (ii) monophyletic groups use qualitatively similar structures; and (iii) the hue of the blue colour is characteristic for the microstructure and nanostructure of the body of the scales.
The structure and mechanical properties of amorphous and nanocrystalline Fe–Si–B alloys
Authors: SYPIEŃ A. , KUSIŃSKI J.
Published: November 2006

This article describes the results of investigations of the microstructure of failure surfaces and the mechanism of deformation of an amorphous Fe80Si11B9 alloy, nanocrystallized with the use of Nd:YAG pulsed laser heating. The research included ‘in situ’ tensile testing in a scanning electron microscope. Mechanical properties were also measured on an Instron‐type machine for the amorphous and nanocrystalline alloys. The mechanical tensile tests performed on the amorphous and nanocrystalline samples showed a ductile fracture surface with very high fracture stress. Detailed observations of the flow deformation and fractures revealed the relationship between the quenched‐in crystalline and mechanical behaviour.
Characterization of the near‐surface layers of carbon steels modified by interaction with intense pulsed plasma beams: scanning electron microscopy investigations
Authors: SARTOWSKA B. , PIEKOSZEWSKI J. , WALIŚ L. , STANISŁAWSKI J. , NOWICKI L. , RATAJCZAK R.
Published: November 2006

Modification of materials is a wide area in materials science, especially surface modification. To investigate the results of the modification process, treated and nontreated samples were compared. Intense plasma pulses of argon or nitrogen were used to irradiate the carbon steels. In all samples, the near‐surface layer was melted. Results of scanning electron microscopy investigations of the surface morphology and cross‐sections, as well as the results of tribological tests, are presented. The obtained results allowed us to draw conclusions about changes in material properties and to propose subsequent studies using other investigation techniques.
Transmission electron microscopy analysis of phase separation in GaInAsSb films grown on GaSb substrate
Authors: SZCZESZEK P. , AMARIEI A. , SCHÖNE J. , ZOULIS G. , VOUROUTZIS N. , POLYCHRONIADIS E. K. , STRÓŻ D.
Published: November 2006

The GaSb‐based quaternary alloys are a good choice for thermophotovoltaic applications. The thermophotovoltaic cell converts infrared radiation to electricity, using the same principles as photovoltaic devices. The aim of the present work was the microstructural study of such an alloy, namely Ga0.84In0.16As0.12Sb0.88. A thin film of the material was grown by metal organic vapour phase epitaxy on a (100)α→[111]B (α = 2°, 4°, 6°) GaSb substrate. The GaInAsSb alloy has an appropriate band gap, but suffers from a phase separation consisting of GaAs‐rich and InSb‐rich regions that is disadvantageous for cell efficiency. In this work, we employed a morphological approach to phase separation, with the use of conventional transmission electron microscopy and atomic force microscopy. The phase separation occurs in two different orientations: parallel to the growth direction (vertical) and inclined (lateral). After application of fast Fourier transformation filtering, the vertical periodicity was found to be λ = 5 nm for the pair (black and white) of layers independently of the cut‐off angle, whereas the lateral periodicity was related to it.
Investigation of Si–Au vicinal surfaces using scanning tunnelling microscopy and reflection high‐energy electron diffraction
Authors: MAZUREK P. , PAPROCKI K. , MITURA Z.
Published: November 2006

Silicon vicinal surfaces can be successfully used as substrates for the preparation of one‐dimensional nanostructures. The quality of the structures prepared may be controlled using scanning tunnelling microscopy, as shown in this work. Additionally, it is possible to obtain valuable information using reflection high‐energy electron diffraction. A typical way of employing reflection high‐energy electron diffraction is to observe patterns of scattered electrons on a screen. However, it is possible to obtain more detailed information on the arrangement of atoms at the surface if azimuthal plots are collected. Azimuthal plots are measured by recording the intensity of specularly reflected electrons during the rotation of the sample around an axis perpendicular to its surface. So far, only flat surfaces have been examined in such a way. In this work, it is shown that such data, containing interesting features, can also be collected for vicinal surfaces.
Yeast complementation reveals a role for an Arabidopsis thaliana late embryogenesis abundant (LEA)‐like protein in oxidative stress tolerance
Authors: Mowla Shaheen B. , Cuypers Ann , Driscoll Simon P. , Kiddle Guy , Thomson Jennifer , Foyer Christine H. , Theodoulou Frederica L.
Published: November 2006

A functional cloning approach using the oxidant‐sensitive yeast mutant, Δyap1, was employed to identify plant genes involved in tolerance of oxidative stress. In this screen, we identified an Arabidopsis late embryogenesis‐abundant (LEA)‐like protein, AtLEA5, which increased the tolerance of Δyap1 cells to the oxidants H2O2, diamide, menadione and tert‐butyl hydroperoxide. Unlike canonical LEAs, AtLEA5 is constitutively expressed in roots and reproductive organs but not in seeds. In leaves of short‐day grown plants, AtLEA5 transcripts exhibited a diurnal pattern of regulation, where transcripts were repressed in the light and abundant in the dark. Expression of AtLEA5 in leaves was induced by oxidants, ABA and dehydration. Use of abi1‐1 (ABA‐insensitive) and aba1‐1 (ABA‐deficient) Arabidopsis mutants indicated that drought induction of AtLEA5 required ABA synthesis but was independent of the ABI1 gene product. Abscisic acid and H2O2 induction of AtLEA5 was also independent of the OXI1 protein kinase. Constitutive overexpression of AtLEA5 resulted in increased root growth and shoot biomass, both in optimal conditions and under H2O2 stress. However, in comparison with wild type, photosynthesis in overexpressing plants was more susceptible to drought. These features suggest that AtLEA5 has a unique function among LEA proteins in that it plays a specific role in protection against oxidative stress involving decreased photosynthesis. This protein functions as part of a complex network of defences that contribute to robustness of plants under stress by minimizing the negative effects of oxidation.
RNAi‐induced silencing of gene expression in strawberry fruit (Fragaria × ananassa) by agroinfiltration: a rapid assay for gene function analysis
Authors: Hoffmann Thomas , Kalinowski Gregor , Schwab Wilfried
Published: November 2006

Intron‐containing constructs encoding self‐complementary ‘hairpin’ RNA (ihpRNA) have the potential to efficiently silence genes in a range of plant species. In this study we demonstrate the silencing of a ripening‐related chalcone synthase (CHS) gene in strawberry fruits (Fragaria × ananassa cv. Elsanta) by a construct (ihpRNA) containing the partial sense and corresponding antisense sequences of CHS separated by an intron obtained from a F. × ananassa quinone oxidoreductase gene. An Agrobacterium strain carrying a T‐DNA expressing the ihpRNA transgene was injected with a syringe into the receptacles of growing fruits still attached to the plant about 14 days after pollination. As a consequence of the reduced levels of CHS mRNA and enzymatic CHS activity, the levels of anthocyanins were downregulated and precursors of the flavonoid pathway were shunted to the phenylpropanoid pathway leading to a large increases in levels of (hydroxy) cinnamoyl glucose esters. We anticipate that this technique in combination with metabolite profiling analysis will be useful for studying the function of unknown genes during the development and ripening of strawberry fruit.
Hydrogen peroxide, nitric oxide and cytosolic ascorbate peroxidase at the crossroad between defence and cell death
Authors: De Pinto Maria Concetta , Paradiso Annalisa , Leonetti Paola , De Gara Laura
Published: November 2006

An increase in the production of reactive oxygen species (ROS) is a typical event occurring during different stress conditions and activating conflicting responses in plants. In order to investigate the relevance of different timing and amounts of ROS production, tobacco (Nicotiana tabacum) Bright Yellow‐2 (TBY‐2) cells were incubated with different amounts of glucose plus glucose oxidase, for generating H2O2during time, or directly with known amounts of H2O2. Data presented here indicate that, in TBY‐2 cells, a difference in H2O2level is a critical point for shifting metabolic responses towards strengthening of antioxidant defences, or their depletion with consequent cell death. Timing of ROS production is also critical because it can determine programmed cell death (PCD) or necrosis. Depending on the different kinds of activated cell death, ascorbate (ASC) and glutathione (GSH) pools are altered differently. Moreover, an H2O2‐dependent activation of nitric oxide synthesis is triggered only in the conditions inducing PCD. Ascorbate peroxidase (APX) has been analysed under different conditions of H2O2generation. Under a threshold value of H2O2overproduction, a transient increase in APX occurs, whereas under conditions inducing cell necrosis, the activity of APX decreases in proportion to cell death without any evident alteration in APX gene expression. Under conditions triggering PCD, the suppression of APX involves both gene expression and alteration of the kinetic characteristics of the enzyme. The changes in ASC, GSH and APX are involved in the signalling pathway leading to PCD, probably contributing to guaranteeing the cellular redox conditions required for successful PCD.
Alternative complex formation of the Ca2+‐regulated protein kinase CIPK1 controls abscisic acid‐dependent and independent stress responses in Arabidopsis
Authors: D'Angelo Cecilia , Weinl Stefan , Batistic Oliver , Pandey Girdhar K. , Cheong Yong Hwa , Schültke Stefanie , Albrecht Veronica , Ehlert Britta , Schulz Burkhard , Harter Klaus , Luan Sheng , Bock Ralph , Kudla Jörg
Published: November 2006

Intracellular release of calcium ions belongs to the earliest events in cellular stress perception. The molecular mechanisms integrating signals from different environmental cues and translating them into an optimized response are largely unknown. We report here the functional characterization of CIPK1, a protein kinase interacting strongly with the calcium sensors CBL1 and CBL9. Comparison of the expression patterns indicates that the three proteins execute their functions in the same tissues. Physical interaction of CIPK1 with CBL1 and CBL9 targets the kinase to the plasma membrane. We show that, similarly to loss of CBL9 function, mutation of either CBL1 or CIPK1 renders plants hypersensitive to osmotic stress. Remarkably, in contrast to the cbl1 mutant and similarly to the cbl9 mutant, loss of CIPK1 function impairs abscisic acid (ABA) responsiveness. We therefore suggest that, by alternative complex formation with either CBL1 or CBL9, the kinase CIPK1 represents a convergence point for ABA‐dependent and ABA‐independent stress responses. Based on our genetic, physiological and protein–protein interaction data, we propose a general model for information processing in calcium‐regulated signalling networks.
AKRP and EMB506 are two ankyrin repeat proteins essential for plastid differentiation and plant development in Arabidopsis
Authors: Garcion C. , Guilleminot J. , Kroj T. , Parcy F. , Giraudat J. , Devic M.
Published: November 2006

EMB506 is a chloroplast protein essential for embryo development, the function of which is unknown. A two‐hybrid interaction screen was performed to provide insight into the role of EMB506. A single interacting partner, AKRP, was identified among a cDNA library from immature siliques. The AKR gene (Zhang et al., 1992, Plant Cell 4, 1575–1588) encodes a protein containing five ankyrin repeats, very similar to EMB506. Protein truncation series demonstrated that both proteins interact through their ankyrin domains. Using reverse genetics, we showed that loss of akr function resulted in an embryo‐defective (emb) phenotype indistinguishable from the emb506 phenotype. Transient expression of the signal peptide of AKRP fused to green fluorescent protein demonstrated the chloroplast localization of AKRP. The ABI3 promoter was used to express AKR in a seed‐specific manner in order to analyse the post‐embryonic effect of AKR loss of function in akr/akr seedlings. Homozygous fertile and viable akr/akr plants were obtained. These plants exhibited mild to severe defects in chloroplast and leaf cellular organization. We conclude that EMB506 and AKRP are involved in crucial and tightly controlled events in plastid differentiation linked to cell differentiation, morphogenesis and organogenesis during the plant life cycle.
Polyomavirus (BK) in pediatric renal transplants: Evaluation of viremic patients with and without BK associated nephritis
Authors: Hymes Leonard C. , Warshaw Barry L.
Published: November 2006

Abstract:  Polyoma BK virus (BKV) is emerging as a significant complication in renal transplantation, which may lead to renal dysfunction and graft loss caused by BK nephritis (BKN). We report the management and outcome of 20 children who developed BK viremia. Serum polymerase chain reaction (PCR) for BKV DNA was measured monthly for the first year in transplant recipients and every six months thereafter, or for unexplained creatinine elevation. With seroconversion to +PCR, patients were managed with reduction of immunosuppression. Renal biopsy was performed if PCR or creatinine did not improve. From June 2003 to January 2006, 20 children seroconverted for BKV at 23 to 1410 days post‐transplant (mean 467 days). Sixteen underwent renal biopsy. Eight displayed BKN, three acute rejection and five were normal. Patients with BKN displayed higher PCR and serum creatinine and presented later than children with viremia without BKN. There were no differences between the two groups for age, gender, donor source or immunosuppression. Seven children with BKN received treatment with cidofovir. Thirteen patients (65%) remained PCR+ after reduction of immunosuppression or treatment with cidofovir. Renal function was stable in 16 children (80%) at 13 ± 6 months after seroconversion. Four patients with BKN demonstrated progressive loss of renal function. BKV infection in children can occur as an early complication or may develop years after transplantation. Patients with BKN presented later and displayed higher viral loads and serum creatinine than viremic patients without BKN. Children with BKN remained PCR+ despite reduction of immunosuppression or treatment with cidofovir and were at greater risk for loss of renal function.
Surgical guidelines for the management of extra‐hepatic portal vein obstruction
Authors: Superina Riccardo , Shneider Benjamin , Emre Sukru , Sarin Shiv , De Ville de Goyet Jean
Published: November 2006

Abstract:  The recent introduction of the meso Rex bypass raises a possible paradigm shift in the therapeutic approach to extra‐hepatic portal vein obstruction (EHPVO). Long‐term follow‐up of patients with EHPVO has revealed a variety of complications including variceal hemorrhage, hypersplenism, biliopathy, growth/development retardation and neuropsychiatric disease. The meso Rex bypass restores physiologic blood flow to the liver. Thus, when feasible, the meso Rex bypass should be considered in patients with clinically significant manifestations of EHPVO. The opinions of a panel of experts regarding the surgical approach to the management of EHPVO are presented.
Prion‐removal capacity of chromatographic and ethanol precipitation steps used in the production of albumin and immunoglobulins
Authors: Thyer J. , Unal A. , Thomas P. , Eaton B. , Bhashyam R. , Ortenburg J. , Uren E. , Middleton D. , Selleck P. , Maher D.
Published: November 2006

Background and Objectives  Although there is no epidemiological evidence to suggest that classical Creutzfeldt–Jakob disease (CJD) is transmitted through blood or blood products, the variant form (vCJD) has been implicated in transmission via packed red blood cells. The potential threat of the infectious agent contaminating plasma pools has led to manufacturing processes being examined for capacity to remove prions. The objective of these studies was to examine the prion‐removal potential of the chromatographic purification and ethanol precipitation steps used to fractionate immunoglobulins and albumin from human plasma.

Materials and Methods  Western blot assay was used to examine the partitioning of proteinase K‐resistant scrapie prion protein (PrPsc) over DEAE Sepharose, CM Sepharose and Macro‐Prep High Q chromatographic columns, utilizing microsomal scrapie 263K spiked into each scaled down feedstream and assayed after each chromatographic step. In further studies, bioassay in C57 black mice was used and spikes of 10 000 g clarified brain homogenate of scrapie ME7 were added to feedstreams before sequences of scaled down chromatographic or Cohn fractionation process steps.

Results  The microsomal spiking study with Western blot detection demonstrated substantial partitioning of PrPsc away from the target proteins in all ion exchange chromatographic steps examined. The log10 reduction factors (LRF) across DEAE Sepharose and CM Sepharose columns for albumin were ≥ 4.0 and ≥ 3.0 respectively. The reductions across DEAE Sepharose and Macro‐Prep High Q for intravenous immunoglobulin were 3.3 and ≥ 4.1 respectively. Bioassay demonstrated LRFs of ≥ 5.6 across the combination of DEAE Sepharose and CM Sepharose columns in the albumin process and ≥ 5.4 across the combination of DEAE Sepharose and Macro‐Prep High Q columns in the intravenous immunoglobulin process. Bioassay studies also demonstrated a LRF of ≥ 5.6 for immunoglobulin produced by Cohn fractionation.

Conclusions  Using rodent‐adapted scrapie as a model, the studies indicated that ion exchange chromatography, as well as Cohn immunoglobulin fractionation have the potential to effectively reduce the load of TSE agents should they be present in plasma pools.

Table of Contents  Ion exchange columns used for production of human albumin and immunoglobulins, as well as Cohn immunoglobulin fractionation, effectively reduce the load of TSE agents should they be present in plasma pools.
Beneficial effects of pentoxifylline on hepatic steatosis, fibrosis and necroinflammation in patients with non‐alcoholic steatohepatitis
Authors: Satapathy Sanjaya K , Sakhuja Puja , Malhotra Veena , Sharma Barjesh C , Sarin Shiv K
Published: November 2006

Background and Aim: Inhibition of tumor necrosis factor (TNF)‐α is a logical approach to manage patients with non‐alcoholic steatohepatitis (NASH). Pentoxifylline reduces TNF‐α and alanine aminotransferase (ALT) levels in patients with NASH. The aim of the present paper was to study if pentoxifylline can improve histological injury in patients with NASH.

Methods: Nine patients (mean age 31.6 ± 7.2 years) with histologically proven NASH and with persistently elevated ALT (>1.5 times) were given pentoxyfylline at a dosage of 400 mg t.i.d. for 12 months. Besides biochemical assessment, a repeat liver biopsy was performed and the degree of inflammation and fibrosis was compared.

Results: After 12 months of therapy a significant reduction in ALT (111 ± 53 IU/Lvs45 ± 19 IU/L,P = 0.003) and aspartate aminotransferase (AST) (61 ± 27 IU/Lvs33 ± 12 IU/L,P = 0.005) levels was observed. Steatosis and lobular inflammation each reduced in 55% and six (67%) patients down‐staged on Brunt's staging (P = 0.009). Four out of six patients with baseline fibrosis had reduction in their fibrosis stage.

Conclusions: Long‐term pentoxyfylline therapy effectively achieves sustained biochemical improvement. This correlates well with histological resolution of the disease.
Rabeprazole delays gastric emptying of a nutrient liquid
Authors: Sanaka Masaki , Anjiki Hajime , Yamamoto Takatsugu , Kuyama Yasushi
Published: November 2006

Background:  It is generally considered that gastric acid suppression delays gastric emptying of solid meals because gastric hypoacidity impairs peptic digestion and antral triturition. Rabeprazole is one of the most potent acid suppressants. We conducted this cross‐over study to investigate if rabeprazole delays gastric emptying of liquid nutrients, for which peptic digestion is unnecessary.

Methods:  On two randomized occasions, 13 healthy male volunteers underwent the 13C‐acetate breath test following ingestion of a 300 kcal‐liquid meal. On one occasion, they had received 20 mg rabeprazole for the preceding 2 days and 1 h before the test. On another, they took no pretreatment. Based on 4 h breath samples, the half 13CO2 excretion time (t1/2b) and the time of maximal excretion (tmax) were calculated as overall measures of gastric emptying. In addition, time profiles of gastric emptying were generated using the Wagner‐Nelson analytical method, which creates the gastric emptying curve as accurately as the scintigraphy.

Results:  Rabeprazole significantly prolonged tmax but unchanged t1/2b. The gastric emptying profiles showed that rabeprazole evoked a segmental slowing of gastric emptying during 0.5–1.25 h of post‐meal ingestion.

Conclusions:  Rabeprazole suppresses gastric emptying of a liquid nutrient 0.5 h after meal ingestion. We have speculated that: (i) rabeprazole delays gastric emptying via a mechanism other than acid‐pepsin maldigestion; and (ii) rabeprazole may intensify the post‐gastric feedback regulation system (>0.5 h of post‐meal).
Endoscopic balloon dilatation of intestinal strictures in Crohn's disease: Safe alternative to surgery
Authors: Ajlouni Yousef , Iser John H , Gibson Peter R
Published: November 2006

Background and Aim:  Endoscopic balloon dilatation (EBD), a non‐surgical treatment option for intestinal strictures in Crohn's disease, appears to be applied infrequently, possibly due to the perceived risk of perforation and early recurrence. This study aimed to determine the outcomes of EBD by a single endoscopist using a defined technique.

Methods:  The records of all patients with Crohn's disease in whom EBD was attempted over a 12‐year period were examined to determine the rate of technical success, complications and outcome. A stricture was defined as that which prevented passage of the 14 mm diameter colonoscope. Technical success was defined as the ability to traverse the stricture postdilatation. Patients were selected on the colonoscopic appearance of the stricture and dilatation was performed using through‐the‐endoscope balloons. Antibiotics were given during and for 7 days postdilatation.

Results:  EBD was attempted on 83 strictures (31 anastomotic and 52 primary) in 37 patients (15 males) and was successful in 75 (90%) of 31 patients. A single dilatation only was required in 21 patients who had a median follow‐up of 20 months (range 6–122 months). Recurrent symptomatic stricture requiring dilatation (eight patients) or surgery (two patients) occurred 8 (1–112) months after the initial dilatation. The only complication occurred in one patient where an intra‐abdominal fistula and abscess were probably related to the dilatation.

Conclusion:  EBD of intestinal strictures associated with Crohn's disease has a low complication rate and leads to prolonged clinical benefit. It should be considered as a real alternative to surgery.
Decoupling Neural Networks From Reality
Authors: Ray William J. , Odenwald Michael , Neuner Frank , Schauer Maggie , Ruf Martina , Wienbruch Christian , Rockstroh Brigitte , Elbert Thomas
Published: November 2006

From a neuroscience perspective, little is known about the long-term effect of torture. Dissociative experiences and posttraumatic stress disorder are often the results of this experience. We examined psychological dissociation within a group of 23 torture victims and report its manifestations within neural networks in the human brain. In particular, we observed that dissociative experiences are associated with slow abnormal brain waves generated in left ventrolateral frontal cortex. Given that focal slow waves often result from depriving neural networks of major input, the present results may indicate decoupling of frontal affective processors from left cortical language areas. This interpretation is consistent with the fact that disturbed access to structured verbal memory concerning traumatic events is a core feature of the dissociative experience.
Major Histocompatibility Complex Alleles, Sexual Responsivity, and Unfaithfulness in Romantic Couples
Authors: Garver-Apgar Christine E. , Gangestad Steven W. , Thornhill Randy , Miller Robert D. , Olp Jon J.
Published: November 2006

Preferences for mates that possess genes dissimilar to one's own at the major histocompatibility complex (MHC), a polymorphic group of loci associated with the immune system, have been found in mice, birds, fish, and humans. These preferences may help individuals choose genetically compatible mates and may adaptively function to prevent inbreeding or to increase heterozy-gosity and thereby immunocompetence of offspring. MHC-dissimilar mate preferences may influence the psychology of sexual attraction. We investigated whether MHC similarity among romantically involved couples (N = 48) predicted aspects of their sexual relationship. All women in our sample normally ovulated, and alleles at three MHC loci were typed for each person. As the proportion of MHC alleles couples shared increased, women's sexual responsivity to their partners decreased, their number of extrapair sexual partners increased, and their attraction to men other than their primary partners increased, particularly during the fertile phase of their cycles.
They All Look the Same to Me (Unless They're Angry)
Authors: Ackerman Joshua M. , Shapiro Jenessa R. , Neuberg Steven L. , Kenrick Douglas T. , Becker D. Vaughn , Griskevicius Vladas , Maner Jon K. , Schaller Mark
Published: November 2006

People often find it more difficult to distinguish ethnic out-group members compared with ethnic in-group members. A functional approach to social cognition suggests that this bias may be eliminated when out-group members display threatening facial expressions. In the present study, 192 White participants viewed Black and White faces displaying either neutral or angry expressions and later attempted to identify previously seen faces. Recognition accuracy for neutral faces showed the out-group homogeneity bias, but this bias was entirely eliminated for angry Black faces. Indeed, when participants' cognitive processing capacity was constrained, recognition accuracy was greater for angry Black faces than for angry White faces, demonstrating an out-group heterogeneity bias.
Is Belief Reasoning Automatic?
Authors: Apperly Ian A. , Riggs Kevin J. , Simpson Andrew , Chiavarino Claudia , Samson Dana
Published: November 2006

Understanding the operating characteristics of theory of mind is essential for understanding how beliefs, desires, and other mental states are inferred, and for understanding the role such inferences could play in other cognitive processes. We present the first investigation of the automaticity of belief reasoning. In an incidental false-belief task, adult subjects responded more slowly to unexpected questions concerning another person's belief about an object's location than to questions concerning the object's real location. Results in other conditions showed that responses to belief questions were not necessarily slower than responses to reality questions, as subjects showed no difference in response times to belief and reality questions when they were instructed to track the person's beliefs about the object's location. The results suggest that adults do not ascribe beliefs to agents automatically.
Dehumanizing the Lowest of the Low
Authors: Harris Lasana T. , Fiske Susan T.
Published: November 2006

Traditionally, prejudice has been conceptualized as simple animosity. The stereotype content model (SCM) shows that some prejudice is worse. The SCM previously demonstrated separate stereotype dimensions of warmth (low-high) and competence (low-high), identifying four distinct out-group clusters. The SCM predicts that only extreme out-groups, groups that are both stereotypically hostile and stereotypically incompetent (low warmth, low competence), such as addicts and the homeless, will be dehumanized. Prior studies show that the medial prefrontal cortex (mPFC) is necessary for social cognition. Functional magnetic resonance imaging provided data for examining brain activations in 10 participants viewing 48 photographs of social groups and 12 participants viewing objects; each picture dependably represented one SCM quadrant. Analyses revealed mPFC activation to all social groups except extreme (low-low) out-groups, who especially activated insula and amygdala, a pattern consistent with disgust, the emotion predicted by the SCM. No objects, though rated with the same emotions, activated the mPFC. This neural evidence supports the prediction that extreme out-groups may be perceived as less than human, or dehumanized.
Fitting in Matters
Authors: Oyserman Daphna , Brickman Daniel , Bybee Deborah , Celious Aaron
Published: November 2006

Minority boys are at risk of academic disengagement. Prior research documents that an aspect of racial-ethnic identity, in-group connection, can buffer against this risk, but that in-group connection is undermined in high-risk neighborhoods. We examined another way that boys may feel connected to the in-group, by looking like in-group members. We hypothesize that physical markers of in-group membership can serve to improve boys' sense of belongingness, thereby facilitating their engagement in school. We tested our model with low-income, high-risk African American (Study 1, n = 102) and Latino (Study 2, n = 66) teens. Hierarchical regression supported our model; dark skin tone was a protective factor (and light skin tone a risk factor) for African American boys, and feeling that one looks Latino was a protective factor (and feeling that one does not look Latino a risk factor) for Latino boys' grades, in-class behavior, and school engagement. Mediational analyses suggest that markers of belongingness have their impact via peer-group choice.
The Contact Hypothesis Revisited
Authors: Henry P.J. , Hardin Curtis D.
Published: November 2006

Although 50 years of research demonstrate that friendly intergroup contact reduces intergroup prejudice, the findings are based solely on self-reported, explicit prejudice. In two parallel experiments examining intergroup contact and prejudice—between Whites and Blacks in the United States (Experiment 1) and between Christians and Muslims in Lebanon (Experiment 2)—we examined whether intergroup status differences moderate contact effects on implicit prejudice, as well as explicit prejudice. Both experiments replicated the standard effect of contact on explicit prejudice. They also demonstrated that intergroup contact reduces implicit prejudice among low-status groups. In Experiment 1, the implicit prejudice of Blacks toward Whites (but not Whites toward Blacks) was reduced as a function of friendly contact. In Experiment 2, the implicit prejudice of Muslims toward Christians (but not Christians toward Muslims) was reduced as a function of friendly contact.
Heterosocial Perceptual Organization
Authors: Farris Coreen , Viken Richard J. , Treat Teresa A. , McFall Richard M.
Published: November 2006

Luce's (1959, 1963) choice model was used to characterize individual differences in men's perception of women's affect as friendly, sexually interested, sad, or rejecting. Women's clothing styles were associated with differences in the model's parameters. Sensitivity to sadness, rejection, and friendliness declined when women were dressed provocatively, whereas sensitivity to sexual interest increased. Provocative clothing was also associated with an increased bias to assume that positive affect was sexual interest rather than friendliness. Men at risk for perpetrating sexual aggression were less sensitive to women's affect than low-risk men were. They were also more likely than low-risk men to associate provocative clothing with sexual interest, and conservative clothing with friendliness. Results indicate that heterosocial perception may help to predict sexually coercive behavior and may be an important target for intervention.
Choosing an Inferior Alternative
Authors: Russo J. Edward , Carlson Kurt A. , Meloy Margaret G.
Published: November 2006

We show how decision makers can be induced to choose a personally inferior alternative, a strong violation of rational decision making. First, the inferior alternative is installed as the leading option by starting with information that supports this alternative. Then, the decision maker uses the natural process of distorting new information to support whichever alternative is leading. This leader-supporting distortion overcomes the inherent advantages of the superior alternative. The end result is a tendency to choose the self-identified inferior alternative. We trace the choice process to reveal the amount of distortion and its influence on preference. Self-reported awareness of distortion to support the inferior alternative is not related to the amount of distortion. The absence of valid awareness suggests that the manipulation that produces this preference violation is unlikely to be detected and that the distortion is unlikely to be corrected by the decision maker. As expected, given the lack of awareness, final confidence is just as high when the inferior alternative is chosen as when the superior one is. The discussion considers how to prevent an adversary from manipulating one's decisions using this technique.
Correlated evolution of self‐incompatibility and clonal reproduction inSolanum(Solanaceae)
Authors: Vallejo‐Marín Mario , O’Brien Heath E.
Published: November 2006

It has been suggested that clonality provides reproductive assurance in cross‐fertilizing species subject to pollen limitation, relieving one of the main selective pressures favoring the evolution of self‐fertilization. According to this hypothesis, cross‐fertilizing species subject to pollen limitation should often be clonal. Here, we investigated the association between clonality and a genetic mechanism enforcing outcrossing, self‐incompatibility, inSolanum(Solanaceae).

We collected self‐incompatibility and clonality information on 87 species, and looked for an association between these two traits. To account for the contribution of shared evolutionary history to this association, we incorporated phylogenetic information from chloroplast (NADH dehydrogenase subunit F) sequence data.

We found that self‐incompatibility is strongly associated with clonal reproduction: all self‐incompatible species reproduce clonally, while the absence of clonality is widespread among self‐compatible taxa. The observed correlation persists after taking into account shared phylogenetic history, assumptions about the evolutionary history of self‐incompatibility, uncertainty associated with phylogeny estimation, and associations with life history (annual/perennial).

Our results are consistent with the hypothesis that clonality provides reproductive assurance, and suggest that the consequences of clonal growth in the evolution of plant reproductive strategies may be more significant than previously thought.
Role of Kupffer cells in host defense and liver disease
Authors: Bilzer Manfred , Roggel Frigga , Gerbes Alexander L.
Published: November 2006

Abstract: Kupffer cells (KC) constitute 80–90% of the tissue macrophages present in the body. They reside within the lumen of the liver sinusoids, and are therefore constantly exposed to gut‐derived bacteria, microbial debris and bacterial endotoxins, known to activate macrophages. Upon activation KC release various products, including cytokines, prostanoides, nitric oxide and reactive oxygen species. These factors regulate the phenotype of KC themselves, and the phenotypes of neighboring cells, such as hepatocytes, stellate cells, endothelial cells and other immune cells that traffic through the liver. Therefore, KC are intimately involved in the liver's response to infection, toxins, ischemia, resection and other stresses. This review summarizes established basic concepts of KC function as well as their role in the pathogenesis of various liver diseases.