bluuebunny/crossref_metadata_2025 huggingface dataset:
Secretion signal recognition by YscN, the
Yersinia
type III secretion ATPase
Authors: Sorg Joseph A. , Blaylock Bill , Schneewind Olaf
Published: October 2006

Yersinia
type III machines secrete protein substrates across the bacterial envelope. Secretion signals of some substrates have been identified; however, the mechanisms whereby these signals interact with type III machines are not known. Here we show that fusion of YopR, an early secretion substrate, to the N terminus of dihydrofolate reductase (DHFR) or other tightly folded proteins generates impassable hybrids that cannot travel the type III pathway. YopR hybrids capture YscN, the ATPase that provides energy for type III transport reactions, in the bacterial cytoplasm. Eleven N-terminal residues function as the YopR secretion signal, which is required for both binding to YscN and blocking the type III pathway. When expressed during type III machine assembly, YopR-DHFR blocks all secretion. Delayed expression of YopR-DHFR, when yersiniae have already engaged the type III pathway, blocks secretion of early (YscP) but not of late (effector Yops) substrates. These observations support a model whereby type III machines are programmed to secrete a sequence of proteins that can be disrupted when an impassable early substrate interacts with the YscN ATPase and blocks the transport of late substrates.
Financial support at the time of paper acceptance: a survey of three medical journals
Authors: Schroter Sara , Tite Leanne , Kassem Ahmed
Published: October 2006

The author‐pays model (open access publishing funded through author charges) is dependent on authors having access to financial support at the time their research papers are accepted. We conducted an author survey to determine the availability of external funding for publication charges at different points in the research process. Of the 377/524 (72%) who responded, 62% (233/377) received external funding to support their study, but with notable differences between journals. Only 25% (95/377) could withdraw funds from a grant at the time of paper acceptance. The grant was closed at this time for almost half (105/233, 45%) of those who were externally funded. Non‐externally funded research was largely supported through departmental resources (56%, 80/144) or carrying out research in own time (63%, 91/144). To conclude, a large proportion of published research is not externally funded, and many funded researchers do not have access to financial support at the time their paper is accepted for publication.
Proteasomal Ubiquitin Receptor RPN-10 Controls Sex Determination inCaenorhabditis elegans
Authors: Shimada Masumi , Kanematsu Kenji , Tanaka Keiji , Yokosawa Hideyoshi , Kawahara Hiroyuki
Published: October 2006

The ubiquitin-binding RPN-10 protein serves as a ubiquitin receptor that delivers client proteins to the 26S proteasome. Although ubiquitin recognition is an essential step for proteasomal destruction, deletion of the rpn-10 gene in yeast does not influence viability, indicating redundancy of the substrate delivery pathway. However, their specificity and biological relevance in higher eukaryotes is still enigmatic. We report herein that knockdown of the rpn-10 gene, but not any other proteasome subunit genes, sexually transforms hermaphrodites to females by eliminating hermaphrodite spermatogenesis in Caenorhabditis elegans. The feminization phenotype induced by deletion of the rpn-10 gene was rescued by knockdown of tra-2, one of sexual fate decision genes promoting female development, and its downstream target tra-1, indicating that the TRA-2–mediated sex determination pathway is crucial for the Δrpn-10–induced sterile phenotype. Intriguingly, we found that co-knockdown of rpn-10 and functionally related ubiquitin ligase ufd-2 overcomes the germline-musculinizing effect of fem-3(gf). Furthermore, TRA-2 proteins accumulated in rpn-10-defective worms. Our results show that the RPN-10–mediated ubiquitin pathway is indispensable for control of the TRA-2–mediated sex-determining pathway.
Biomimetic mushroom-shaped fibrillar adhesive microstructure
Authors: Gorb S , Varenberg M , Peressadko A , Tuma J
Published: October 2006

To improve the adhesive properties of artificial fibrillar contact structures, the attachment systems of beetles from the family Chrysomelidae were chosen to serve as a model. Biomimetic mushroom-shaped fibrillar adhesive microstructure inspired by these systems was characterized using a variety of measurement techniques and compared with a control flat surface made of the same material. Results revealed that pull-off force and peel strength of the structured specimens are more than twice those of the flat specimens. In contrast to the control system, the structured one is found to be very tolerant to contamination and able to recover its adhesive properties after being washed in a soap solution. Based on the combination of several geometrical principles found in biological attachment devices, the presented microstructure exhibits a considerable step towards the development of an industrial dry adhesive.
Supporting anthropological research with efficient rotation invariant shape similarity measurement
Authors: Wei L , Keogh E , Xi X , Lee S.-H
Published: October 2006

The matching of two-dimensional shapes is an important problem with many applications in anthropology. Examples of objects that anthropologists are interested in classifying, clustering and indexing based on shape include bone fragments, projectile points (arrowheads/spearpoints), petroglyphs and ceramics. Interest in matching such objects originates from the fundamental question for many biological anthropologists and archaeologists: how can we best quantify differences and similarities? This interest is fuelled in part by a movement that notes: ‘an increasing number of archaeologists are showing interest in employing Darwinian evolutionary theory to explain variation in the material record’. Aiding such research efforts with computers requires a shape similarity measure that is invariant to many distortions, including scale, offset, noise, partial occlusion, etc. Most of these distortions are relatively easy to handle, either in the representation of the data or in the similarity measure used. However, rotation invariance seems to be uniquely difficult. Current approaches typically try to achieve rotation invariance in the representation of the data, at the expense of poor discrimination ability, or in the distance measure, at the expense of efficiency. In this work, we show that we can take the slow but accurate approaches and dramatically speed them up. On real world problems, our technique can take current approaches and make them four orders of magnitude faster, without false dismissals. Moreover, our technique can be used withanyof the dozens of existing shape representations and withallthe most popular distance measures, including Euclidean distance, dynamic time warping and longest common subsequence. We show the applications of our work to several important problems in anthropology, including clustering and indexing of skulls, projectile points and petroglyphs.
Novel phenomena-based dynamic model of carbon black/composite vapour sensors
Authors: Yates James W.T , Chappell Michael J , Gardner Julian W
Published: October 2006

A novel physically based mathematical model of carbon black/polymer vapour sensors is described, which incorporates parameters that have physical meaning. This model has an analytical solution and so requires negligible computational power to analyse a sensor's response to a particular form of input. Another advantage of this modelling approach is that the environmental dependencies of sensor responses may be compensated for and so help in the design of better pattern-recognition algorithms for electronic nose systems. This also means that the underlying chemistry of the sensors may be decoupled from their physical non-analyte specific properties. Experimentally, three different conducting nanocomposite polymers, poly(styrene-co-butadine), poly(ethyl-co-vinyl acetate) and poly(caprolactone), were tested. Each experiment consisted of separate exposures of the sensors to acetone and ethanol vapour in ambient air. A total of 336 such experiments were performed over a two-week period. The model was validated with respect to these data and was then fitted to the two vapour responses simultaneously, demonstrating its applicability to ‘real world’ systems. The temperature dependence of the model parameters was judged to be the most important factor and it needs to be compensated for when applying this type of sensor in practice.
Rayleigh waves guided by topography
Authors: Adams Samuel D.M , Craster Richard V , Williams Duncan P
Published: October 2006

We consider wave propagation along the surface of an elastic half-space, whose surface is flat except for a straight, infinite length, ridge or trench that does not vary in its cross-section. We seek to resolve the issue of whether such a perturbed surface can support a trapped wave, whose energy is localized to within some vicinity of the defect, and explain physically how this trapping occurs. First, the trapping is addressed by developing an asymptotic scheme, which exploits a small parameter associated with the surface variation, to perturb about the base state of a flat half-space (which supports a surface wave, as demonstrated by Lord Rayleigh in 1885). We then provide convincing numerical evidence to support the results obtained from the asymptotic scheme; however, no rigorous proof of existence is presented.
Metastatic tumor antigen 3 is a direct corepressor of the Wnt4 pathway
Authors: Zhang Hao , Singh Rajesh R. , Talukder Amjad H. , Kumar Rakesh
Published: October 2006

Here we show that expression of MTA3 inhibits ductal branching in virgin and pregnant murine transgenic mammary glands. MTA3 also suppresses the Wnt4 pathway and, thus, these findings parallel phenotypic changes in Wnt4-null mice. MTA3 represses Wnt4 transcription and Wnt4 secretion, inhibiting Wnt-target genes in mammary epithelial cells. Accordingly, knockdown of endogenous MTA3 stimulates Wnt4 expression and Wnt cellular targets. The MTA3–NuRD (nucleosome remodeling and deacetylase) complex physically interacts with the Wnt4 chromatin in an HDAC-dependent manner, leading to suppression of the Wnt4 gene and Wnt4-dependent morphogenesis. These findings identify MTA3 as an upstream physiologic repressor of Wnt4 in mammary epithelial cells.
eDrug: a dynamic interactive electronic drug formulary for medical students
Authors: Maxwell Simon R. J. , McQueen Daniel S. , Ellaway Rachel
Published: October 2006

What is already known about this subject

• Delivering education about an ever‐increasing number of prescribable drugs to medical students represents a major challenge.

• Drug names are generally not logical or intuitive, and many students find learning them akin to learning a foreign language.

• Pharmacology and therapeutics teaching is struggling for visibility in some integrated medical curricula.

What this study adds

• Development of electronic tools allowing web delivery of a restricted student formulary facilitates dynamic access to core learning materials, improves the profile of this aspect of the curriculum and is highly appreciated by students.

Aims

Prescribing drugs is a key responsibility of a doctor and requires a solid grounding in the relevant scientific disciplines of pharmacology and therapeutics (PT). The move away from basic science disciplines towards a more system‐based and integrated undergraduate curriculum has created difficulties in the delivery of PT teaching in some medical schools. We aimed to develop a web‐based strategy to overcome these problems and improve the PT learning experience.

Methods

We designed and introduced ‘eDrug’, a dynamic interactive web‐based student formulary, as an aid to teaching and learning of PT throughout a 5‐year integrated medical curriculum in a UK medical school of 1300 students. This was followed by a prospective observational study of student‐reported views about its impact on their PT learning experience.

Results

eDrug was rated highly by students and staff, with the main benefits being increased visibility of PT in the curriculum, clear identification of core drugs, regular sourcing of drug information via direct links to accredited sources including the British National Formulary, prioritization of learning, immediate access and responsiveness. It has also served as a focus of discussion concerning core PT learning objectives amongst staff and students.

Conclusions

Web‐based delivery of PT learning objectives actively supports learning within an integrated curriculum.
Evaluation of flurbiprofen urinary ratios asin vivoindices for CYP2C9 activity
Authors: Zgheib N. K. , Frye R. F. , Tracy T. S. , Romkes M. , Branch R. A.
Published: October 2006

Aims

We investigated flurbiprofen pharmacokinetics in 12 volunteers to develop a phenotypic trait measure that correlates with the fractional clearance to 4′‐hydroxyflurbiprofen. The effect of the CYP2C9 inhibitor fluconazole on flurbiprofen metabolism was also evaluated.

Methods

Flurbiprofen pharmacokinetics were evaluated before and after the first and seventh doses of fluconazole. The urinary recovery ratio was calculated as FLRR = 4′‐OHF/[4′‐OHF + Ftot] and the urinary metabolic ratio was calculated as FLMR = 4′‐OHF/Ftot, where 4′‐OHF andFtotrepresent total (conjugated and unconjugated) amounts recovered in urine.

Results

There was a statistically significant relationship between the 4′‐OHF formation clearance (4OHCLf) and both the 8‐h FLRR and the 8‐h FLMR with and without administration of fluconazole. The flurbiprofen apparent oral clearance (CL/F) was decreased by 53% [90% confidence interval (CI) −58, −48] and 64% (90% CI −69, −59), respectively, after administration of one and seven doses of fluconazole when compared with administration of flurbiprofen alone; similarly, the 4OHCLf decreased by 69% (90% CI −74, −64) and 78% (90% CI −83, −73), the 8‐h FLRR decreased by 35% (90% CI −41, −29) and 40% (90% CI −46, −35) and the 8‐h FLMR decreased by 61% (90% CI −65, −58) and 67% (90% CI −70, −63). The magnitude of decrease in CL/Fand 4OHCLf was greater after seven doses compared with after one dose of fluconazole (P < 0.005).

Conclusions

This study provides strong evidence that both the 8‐h FLRR and the 8‐h FLMR are suitable phenotypic indices for CYP2C9 activity.
Characterizing new users of NSAIDs before and after rofecoxib withdrawal
Authors: Usher Cara , Bennett Kathleen , Teeling Mary , Feely John
Published: October 2006

What is already known about this subject

• Public concern regarding the cardiovascular safety of the COX‐2 inhibitors began with the withdrawal of rofecoxib from the market in September 2004.

• Since then, a myriad of evidence has pointed towards an adverse cardiovascular effect of other COX‐2 inhibitors in persons with cardiovascular risk.

• This study examines the impact of the clinical trial publicity and drug regulatory advice on nonsteroidal anti‐inflammatory drug (NSAID) prescribing in patients in general practice with known cardiovascular risk both before and after the rofecoxib withdrawal.

What this study adds

• Results from this study indicate that the profile of new users of NSAIDs and COX‐2 inhibitors did not change despite new information becoming available.

• This may highlight the uncertainty experienced by prescribers of treatment alternatives available and the lack of unbiased information at this time for at‐risk groups.

Aims

To characterize patients initiated on nonsteroidal anti‐inflammatory drugs (NSAIDs), pre and postrofecoxib withdrawal, by age, gender and concomitant cardiovascular (CV) therapy.

Methods

A national primary care prescription database was used to identify patients who initiated NSAID therapy pre and postrofecoxib withdrawal. Patients receiving CV therapy were identified in the same periods also. Adjusted odds ratios (OR) and 95% confidence intervals are presented.

Results

Female patients [OR = 1.15 (1.11, 1.19)], those over 65 years [OR = 2.76 (2.65, 2.86)] and those at CV risk [OR = 1.72 (1.67, 1.79)] were more likely to start on celecoxib (over a nonselective NSAID) than male patients, those under 65 years and those not at CV risk. Similar results were found for rofecoxib and nimesulide. Postwithdrawal analysis showed results comparable to the prewithdrawal period.

Conclusion

The results highlight a possible uncertainty experienced by prescribers of treatment alternatives available and a lack of unbiased information at this time for at‐risk groups.
Consumption of carbonated drinks in adolescents: a transtheoretical analysis
Authors: Buchanan H. , Coulson N. S.
Published: October 2006

Background  Adolescents consume a high level of carbonated drinks and this may have significant adverse effects for their weight and oral health. Therefore, we examined the application of key constructs of the Transtheoretical Model (stages of change, decisional balance and self‐efficacy) and health as a value (both general and oral) to adolescent carbonated drink consumption and to identify any gender differences.

Methods  A total of 399 adolescents (mean age 12.57 years, SD = 1.54) completed a questionnaire measuring: stage of change, decisional balance, self‐efficacy, carbonated drink consumption and attitudes to health and healthy teeth.

Results  Over half of the adolescents (55%) were classified into one of the pre‐action stages (i.e. precontemplation or contemplation) and males were more likely to be represented in the precontemplation stage than females. Significant associations with stage of change, decisional balance and self‐efficacy were found, though there was no association with attitudes to health (general or oral).

Conclusion  The findings suggest that the Transtheoretical Model (and its key constructs) may be a useful framework through which more tailored health promotion interventions can be designed.
Plasma 1,25‐dihydroxyvitamin D levels in primary hyperparathyroidism depend on sex, body mass index, plasma phosphate and renal function
Authors: Moosgaard B. , Vestergaard P. , Heickendorff L. , Mosekilde L.
Published: October 2006

Background  Primary hyperparathyroidism (PHPT) is characterized by elevated plasma levels of PTH and calcium with reduced plasma phosphate. Physiologically, renal 1α,25‐dihydroxyvitamin D [1,25(OH)2D] production is stimulated by PTH and phosphate deprivation, and inhibited by 1,25(OH)2D itself and calcium.

Aim  To investigate relations between circulating levels of 1,25(OH)2D, 25‐dihydroxyvitamin D (25OHD), PTH, calcium, phosphate, renal function and skeletal complications in patients with PHPT.

Design  Cross‐sectional study.

Material  Two hundred and fifty‐two consecutive hypercalcaemic Caucasian patients aged 24–91 (median 65·9) years (85·3% females) with PHPT.

Results  In patients with PHPT, plasma 1,25(OH)2D was increased by 27%[107 (9–250) pmol/l, median (range)] compared to controls [84 (18–172) pmol/l, P < 0·001]. In univariate models, plasma 1,25(OH)2D depended inversely on age (r = –0·23, P < 0·001) and plasma phosphate (r = –0·23, P < 0·001) and positively on plasma calcium (r = 0·14, P < 0·05), plasma 25OHD (r = 0,15, P < 0·05) and creatinine clearance rate (r = 0·32, P < 0·001). In the final multiple regression model, plasma 1,25(OH)2D depended positively on renal function (rp = 0·43, P < 0·001) and female sex (rp = 0·15, P < 0·05) but inversely on body mass index (BMI; rp = −0·23, P < 0·005) and plasma phosphate (rp = −0·18, P < 0·05). Plasma 1,25(OH)2D correlated positively with renal calcium excretion and inversely with lumbar spine bone mineral density (BMD) but was not associated with risk of fractures or renal stones.

Conclusion  Patients with PHPT have elevated plasma 1,25(OH)2D levels but, to a large extent, individual values overlap controls. The increase in plasma 1,25(OH)2D depends on renal function, hypophosphataemia and the female sex and is attenuated by high BMI. High plasma 1,25(OH)2D is associated with higher plasma calcium levels.
Imaging of high‐angle annular dark‐field scanning transmission electron microscopy and observations of GaN‐based violet laser diodes
Authors: SHIOJIRI M. , SAIJO H.
Published: October 2006

The first part of this paper is devoted to physics, to explain high‐angle annular dark‐field scanning transmission electron microscopy (HAADF‐STEM) imaging and to interpret why HAADF‐STEM imaging is incoherent, instructing a strict definition of interference and coherence of electron waves. Next, we present our recent investigations of InGaN/GaN multiple quantum wells and AlGaN/GaN strained‐layer superlattice claddings in GaN‐based violet laser diodes, which have been performed by HAADF‐STEM and high‐resolution field‐emission gun scanning electron microscopy.
Supported metal sulphide nanoclusters studied by HAADF‐STEM
Authors: CARLSSON A. , BRORSON M. , TOPSØE H.
Published: October 2006

The morphology of MoS2 and WS2 nanoclusters supported on high‐surface area graphitic carbon was investigated using high angular annular dark field scanning transmission electron microscopy (HAADF‐STEM). Most of the MoS2 (WS2) nanoclusters contain only a single S‐Mo‐S (S‐W‐S) layer and the most commonly encountered morphology is truncated triangular. This is in contrast to the hexagonal morphology of macroscopic MoS2 (WS2) crystals. When in addition to molybdenum (tungsten), nickel is also present, the regular nanoclusters are truncated to a larger extent, indicating that Ni has influenced the morphology by the formation of so‐called Ni‐Mo‐S (Ni‐W‐S) structures. For these structures, the additional truncations are observed to lead to dodecahedral‐like shapes.
TEM and HREM study of Al3Zr precipitates in an Al‐Mg‐Si‐Zr alloy
Authors: LITYÑSKA L. , ABOU‐RAS D. , KOSTORZ G. , DUTKIEWICZ J.
Published: October 2006

The structure of Al3Zr precipitates in Al‐1.0Mg‐0.6Si‐0.5Zr (in wt.%) alloy was investigated using conventional transmission electron microscopy (TEM) and high‐resolution TEM (HREM). After annealing of the alloy in the temperature range 450–540 °C, spherical precipitates of metastable L12‐Al3Zr phase appeared nearly homogeneously within the matrix, and elongated particles were found at grain boundaries. L12‐structured Al3Zr were about 20–30 nm in diameter and coherent with the matrix. Inside some of them, planar faults parallel to {100} planes were revealed by use of HREM. Most probably, these faults are an indication of the transition stage of transformation to the stable D023‐type Al3Zr phase. The elongated precipitates (about 100 nm) were identified as D022‐type Al3Zr. Energy‐dispersive X‐ray analysis showed that they contain, apart from Al, mainly Zr with small amounts of Si. The substitution of Al by Si increased the stability of the D022‐Al3Zr as compared with D023‐Al3Zr.
Nanoscale scanning transmission electron tomography
Authors: MIDGLEY P. A. , WEYLAND M. , YATES T. J. V. , ARSLAN I. , DUNIN‐BORKOWSKI R. E. , THOMAS J. M.
Published: October 2006

Electron tomography enables the study of complex three‐dimensional objects with nanometre resolution. In materials science, scanning transmission electron microscopy provides images with minimal coherent diffraction effects and with high atomic number contrast that makes them ideal for electron tomographic reconstruction. In this study, we reviewed the topic of scanning transmission electron microscopy‐based tomography and illustrated the power of the technique with a number of examples with critical dimensions at the nanoscale.
Microstructural characterization of nitrided Timetal 834
Authors: MOSKALEWICZ T. , GROGGER W. , CZYRSKA‐FILEMONOWICZ A.
Published: October 2006

The microstructure of Timetal 834, in as‐received condition and after nitriding under glow discharge has been examined by light microscopy and analytical transmission electorn microscopy (TEM) methods (SAED, EDS, EELS and EFTEM). The microstructure of the as‐received alloy consists of the α phase and a small amount of the β phase. Silicide precipitates (Zr5Si4) are present both inside the grains and at the grain boundaries. TEM investigations of cross‐sectional thin foils allow for detailed analysis of the nitrided layer microstructure. It was found that the nitrided layer exhibits a graded character with continuously varying nitrogen content. The outermost sublayer consists of nanocrystals of δ‐TiN. The following sublayers consist mainly of δ′‐Ti2N and ɛ‐Ti2N grains. The last sublayer, closest to the substrate, is identified as a nitrogen‐rich α(N) solid solution containing up to 14 at% of nitrogen.
Structural models for twin interfaces in Pd thin films
Authors: TSIAOUSSIS I. , LIOUTAS CH. B. , FRANGIS N.
Published: October 2006

In a Pd thin film grown on a 6H‐SiC (0001) substrate, several twin interfaces have been observed, classified as (1) {111}Σ = 3 twin interfaces and (2) {}Σ = 3 twin interfaces. The first ones are coherent twin interfaces and in some cases exhibit steps of one or more atomic layers in height. The second ones are perpendicular to the first ones. They usually appear with a rigid‐body displacement, but in some cases no displacement was observed. Models for the interfaces are proposed.
Piezoelectric field around threading dislocation in GaN determined on the basis of high‐resolution transmission electron microscopy image
Authors: MACIEJEWSKI G. , KRET S. , RUTERANA P.
Published: October 2006

A new method of determining the piezoelectric field around dislocations from high‐resolution transmission electron microscopy images is presented. In order to determine the electrical potential distribution near a dislocation core, we used the distortion field, obtained using the geometrical phase method and the non‐linear finite element method. The electrical field distribution was determined taking into account the inhomogeneous strain distribution, finite geometry of the sample and the full couplings between elastic and electrical fields. The results of the calculation for a transmission electron microscopy thin sample are presented.
TEM study of indium and gallium nitride nanocrystals in silica gasses obtained by the sol‐gel method
Authors: KRAJCZYK L. , JABŁOŃSKI J. M. , NYK M. , STRĘK W. , MISIEWICZ J.
Published: October 2006

GaN and InN nanocrystals in silica glasses prepared by the sol‐gel method were studied by transmission electron microscopy techniques. Morphology, structure and phase composition of silica gel containing Ga or In as function of the calcination and nitridation temperature were investigated.
TEM studies of the nitrided Ni‐Ti surface layer
Authors: LELATKO J. , PACZKOWSKI P. , WIERZCHOŃ T. , MORAWIEC H.
Published: October 2006

The structure of surface layer, obtained on the nearly equiatomic Ni‐Ti alloy after nitriding under glow discharge conditions at temperatures 700 or 800 °C, was investigated. The structural characterization of the intruded layer was performed on cross‐sectional thin foils by the use of the transmission and scanning electron microscopes. The obtained results show that the nitrided layers consist mainly of the nanocrystalline TiN phase and small amount of Ti2N. Between the nitrided layers and β‐NiTi matrix an intermediate Ti2Ni phase layer was observed.
Shear banding in twinned structure of copper deformed at 77 K
Authors: PAUL H. A. , MORAWIEC A. , BOUZY E. , FUNDENBERGER J. J. , PIA̧TKOWSKI A.
Published: October 2006

The local crystallography and microstructure within shear bands has been examined in single crystals of {112}<111> orientation of pure copper deformed at 77 K by channel‐die compression to true strains of about 1. Setting up a system for making high‐resolution orientation maps using transmission electron microscopy has provided advantageous circumstances for the analysis of orientation changes within shear bands. The present work shows that, despite the plane strain deformation mode, the mechanism of lattice rotation within emerging shear bands may lead to Goss {110}< 001> and Brass{110}<112> texture components.
Structure studies of ball‐milled ZrCuAl, NiTiZrCu and melt‐spun ZrNiTiCuAl alloys
Authors: DUTKIEWICZ J. , KUBÍČEK M. , PASTRŇÁK M. , MAZIARZ W. , LEJKOWSKA M. , CZEPPE T. , MORGIEL J.
Published: October 2006

ZrNiTiCu and ZrNiTiCuAl alloys were amorphized using either a melt‐spinning or ball‐milling process in a high‐energy planetary mill. The elemental powders were initially blended to the desired composition (in at.%) of Zr, 65; Cu, 27.5; Al, 7.5 and of Ti, 25; Zr, 17; Cu, 29; Ni, 29, respectively. The composition of alloys was chosen to be the same as for the bulk amorphous ZrCuAl and easy glass‐forming ZrNiTiCu alloys. An almost fully amorphous structure was obtained after 80 h of milling in the case of both compositions. Transmission electron microscopy studies of ball‐milled powders revealed the presence of nano‐crystallites [2–5 nm for ZrCuAl and smaller (1–3 nm) for the ZrTiNiCu alloy]. High‐resolution transmission electron microscopy of melt‐spun ZrNiTiCuAl ribbons provided evidence of the amorphous structure.
Defects formed within hardness indenter interaction zone in Al2O3–ZrO2 composite
Authors: SZUTKOWSKA M. , MORGIEL J.
Published: October 2006

The Al2O3−10 wt% ZrO2 composites were subjected to hardness tests using a Vickers diamond indenter up to 98.1 N. The microstructure observation using a transmission electron microscopy technique helped to identify up to four zones differing in defect level and character. The densest dislocation tangles, twins accumulation and frequent presence of three slip systems were found in regions that were in contact with the sides of the diamond pyramid. The second zone, characterized by two, or at least one, active slip systems, started at the bottom of the indentation mark and extended up to a distance comparable with the depth of indentation. In the third zone, with a thickness comparable to that above, only some α‐Al2O3 crystallites showed the presence of dislocations, whereas other crystallites were defect free. In the last zone the alumina crystals were left unaffected but the ZrO2 crystallites showed twinning characteristic of strain‐induced transformation.
Hydrogen‐induced defects in austenite and ferrite of a duplex steel
Authors: GŁOWACKA A. , ŚWIĄTNICKI W. A. , JEZIERSKA E.
Published: October 2006

The influence of hydrogen on the microstructure of two types of austeno‐ferritic duplex stainless steel (Cr26‐Ni6 model steel and Cr22‐Ni5‐Mo3 commercial steel), each of them after two thermo‐mechanical treatments, was investigated. The aim of this study was to reveal microstructural changes appearing during the hydrogen charging and particularly to clarify the occurrence of phase transformations induced by hydrogen. The specific microstructural changes in the ferrite (α) and austenite (γ) of both types of steel were observed. A strong increase of dislocation density was noticed in the α phase. In the case of model steel, longer hydrogen charging times led to significant ferrite grain refinement. In the commercial steel, the strips and twin plates appeared in the ferrite after hydrogenation. The appearance of stacking faults was revealed in the γ phase. The martensite laths appeared in austenite after longer hydrogenation times. It seems that the microstructural changes gave rise to the formation of microcracks in the α and γ phases as well as on the α/γ interphase boundaries.
Scanning electron microscopy and transmission electron microscopy study of hot‐deformed γ‐TiAl‐based alloy microstructure
Authors: CHRAPOŃSKI J. , RODAK K.
Published: October 2006

The aim of this work was to assess the changes in the microstructure of hot‐deformed specimens made of alloys containing 46–50 at.% Al, 2 at.% Cr and 2 at.% Nb (and alloying additions such as carbon and boron) with the aid of scanning electron microscopy and transmission electron microscopy techniques. After homogenization and heat treatment performed in order to make diverse lamellae thickness, the specimens were compressed at 1000 °C. Transmission electron microscopy examinations of specimens after the compression test revealed the presence of heavily deformed areas with a high density of dislocation. Deformation twins were also observed. Dynamically recrystallized grains were revealed. For alloys no. 2 and no. 3, the recovery and recrystallization processes were more extensive than for alloy no. 1.
Effects of hatchling body colour and rearing density on body colouration in last‐stadium nymphs of the desert locust, Schistocerca gregaria
Authors: MAENO KOUTARO , TANAKA SEIJI
Published: October 2006

Abstract The influences of hatchling character and rearing density on body colour at the last‐nymphal stadium are investigated for the desert locust, Schistocerca gregaria. Hatchlings are divided into five groups based on the darkness of the body colour and reared either under isolated or crowded conditions. Two types of body colour variation at the last‐nymphal stadium are separately analysed (i.e. the background colour and black patterns). Under isolated conditions, the background body colour is either greenish or brownish. Most individuals are greenish and the highest percentage of brownish insects is obtained from hatchlings with the darkest body colour. Under crowded conditions, the background colour is yellow or orange and the percentage of yellowish nymphs tends to decrease when they are darker at hatching. The intensity of black patterns differs depending on the body colour at hatching and subsequent rearing density. Most isolated‐reared nymphs exhibit few or no black patterns but nymphs with some black patterns also appear, particularly among those that had been dark at hatching. Under crowded conditions, the black patterns become more intense when they are darker at hatching. Therefore, last‐stadium nymphs with typical solitarious or gregarious body colouration appear when they have the phase‐specific body colouration at hatching as well. The present results demonstrate that both body colour at hatching and rearing density during nymphal development influence body colouration at the last‐nymphal stadium.
Foliar resistance of cacao (Theobroma cacao) toPhytophthora palmivoraas an indicator of pod resistance in the field: interaction of cacao genotype, leaf age and duration of incubation
Authors: Tahi G. M. , Kébé B. I. , Sangare A. , Mondeil F. , Cilas C. , Eskes A. B.
Published: October 2006

The effects were studied of four leaf development stages (LDS) and three durations of incubation (DI) on the accuracy of leaf‐disc tests on eight cacao (cocoa) clones (C) for predicting field resistance to phytophthora pod rot caused byPhytophthora palmivora. The clones were known to possess different general combining abilities (GCA) for pod resistance in the field, evaluated monthly at harvest over a 9‐year period. Disease severity (DS) was affected strongly by C, DI and LDS, with increasing levels of significance. Two‐ and three‐way interaction effects were smaller than the clone effect, but still significant. Clone effects were most significant for LDS3 (i.e. leaves 50–60 days old) and for DI5 and DI7 (observations made 5 and 7 days after inoculation, respectively). Coefficients of rank correlation between DS and field results were significant for seven of the 12 treatments, with highest values obtained again for treatments LDS3/DI5 (r= 0·87) and LSD3/DI7 (r= 0·93). Pooling of data for different LDS and DI treatments did not further improve the correlation with field results. However, these correlations were improved (from an average of 0·74 to 0·88) when the GCA values for field resistance were based on weekly observations, carried out in one year, including losses of pods and cherelles. It was concluded that, when carried out in a standardized manner and under optimal conditions, the leaf‐disc test may explain 75–90% of the genetic variation for field resistance of cacao genotypes toP. palmivora.
Assessment of genetic diversity of Xanthomonas campestris pv. campestris isolates from Israel by various DNA fingerprinting techniques
Authors: Valverde A. , Hubert T. , Stolov A. , Dagar A. , Kopelowitz J. , Burdman S.
Published: October 2006

Three molecular typing methods were used to investigate genetic diversity among Xanthomonas campestris pv. campestris isolates obtained in Israel and others previously obtained from different geographical locations (collection isolates). Using pulsed‐field gel electrophoresis (PFGE), amplified fragment length polymorphism (AFLP) and repetitive sequence‐based PCR (rep‐PCR), 22 different isolates were divided into 11, 12 and 13 differentiated genotypes, respectively. All collection isolates yielded different genotypes and, among the isolates from Israel, several new genotypes were found. These findings not only support the observed heterogeneity within X. campestris pv. campestris, but also suggest that variability at the genomic level in this pathovar is higher than previously estimated. Moreover, while previous studies suggested that PCR patterns obtained with integron‐specific primers are conserved in most X. campestris pathovars, PCR patterns of this element yielded four different types among the X. campestris pv. campestris isolates tested, thus supporting the relatively high diversity in this pathovar. Although differences in pathogenicity were observed among isolates, assays using cauliflower and radish did not indicate a correlation between pathogenicity and genotype.
Reduced activity of plastid protoporphyrinogen oxidase causes attenuated photodynamic damage during high‐light compared to low‐light exposure
Authors: Lermontova Inna , Grimm Bernhard
Published: October 2006

Protoporphyrinogen oxidase (EC 1.3.3.4, PPOX) is the last enzyme in the branched tetrapyrrole biosynthetic pathway, before its substrate protoporphyrin is directed to the Mg and Fe branches for chlorophyll and haem biosynthesis, respectively. The enzyme exists in many plants in two similar isoforms, which are either exclusively located in plastids (PPOX I) or in mitochondria and plastids (PPOX II). Antisense RNA expression inhibited the formation of PPOX I in transgenic tobacco plants, which showed reduced growth rate and necrotic leaf damage. The cytotoxic effect is attributed to accumulation of photodynamically acting protoporphyrin. The expression levels of PPOX I mRNA and protein and the cellular enzyme activities were reduced to similar extents in transgenic plants grown under low‐ or high‐light conditions (70 and 530 μmol photons m−2 sec−1). More necrotic leaf lesions were surprisingly generated under low‐ than under high‐light exposure. Several reasons were explored to explain this paradox and the intriguing necrotic phenotype of PPOX‐deficient plants under both light intensity growth conditions. The same reduction of PPOX expression and activity under both light conditions led to similar initial protoporphyrin, but to faster decrease in protoporphyrin content during high light. It is likely that a light intensity‐dependent degradation of reduced and oxidized porphyrins prevents severe photodynamic leaf damage. Moreover, under high‐light conditions, elevated contents of reduced and total low‐molecular‐weight antioxidants contribute to the protection against photosensitizing porphyrins. These reducing conditions stabilize protoporphyrinogen in plastids and allow their redirection into the metabolic pathway.
Are personnel in transplant hospitals in favor of cadaveric organ donation? Multivariate attitudinal study in a hospital with a solid organ transplant program
Authors: Ríos A. , Ramírez P. , Martínez L. , Montoya M.J. , Lucas D. , Alcaraz J. , Rodríguez M.M. , Rodríguez J.M. , Parrilla P.
Published: October 2006

Abstract:  Introduction:  A considerable number of professionals who work in a hospital could be against organ donation, which means that when the time comes, they could act as an obstacle to donation. The objective of this study was to analyze the attitude of hospital professionals toward organ donation and to determine the factors that influence this attitude in a Spanish center with a transplant program.

Materials and methods:  The study was carried out in a third‐level Spanish hospital with a solid organ transplant program. A random sample was taken (n = 1262) and stratified by job category and type of service. Attitude was evaluated using a validated questionnaire. Contact was made in each service with the person responsible for each of the job categories in order to distribute the survey. The survey was completed anonymously and was self‐administered. Student's t‐test, the chi‐squared test, and logistic regression analysis were applied in the statistical analysis.

Results:  The survey completion rate was 93% (n = 1168). Most respondents were in favor of donation [69% (n = 808)]. Of those who are not in favor, 29% (n = 105) provide fear of apparent death as the reason whilst most do not give a reason (negative assertion; 57%; n = 206). There are many factors related to this attitude toward donation, which are evident in the multivariate analysis: (i) job category, in which physicians are twice as likely to be in favor of donation than ancillary personnel (OR = 2.02); (ii) a respondent's knowledge of brain death (OR = 1.64); (iii) having discussed the matter of organ donation and transplantation within the family (OR = 1.89); (iv) a preference for other options apart from burial (OR = 3.66); (v) being in favor of the performance of autopsy if it were necessary (OR = 2.76); (vi) not being concerned about mutilation of the cadaver (OR = 2); and (vii) having a partner with a favorable attitude toward donation (OR = 2.2).

Conclusions:  Attitude toward cadaveric organ donation among personnel in a transplant hospital is similar to that described in the general public and is determined by many factors. The following factors are most noteworthy: (i) job category; (ii) knowledge of the concept of brain death; (iii) consideration of the matter of donation in the family; and (iv) fear of manipulation of the cadaver. In view of this attitude, which is similar to that of the general public, it is necessary to carry out promotion activities if we want to increase cadaveric donation rates.
The preventive effects of thiopental and propofol on testicular ischemia‐reperfusion injury
Authors: Yagmurdur H. , Ayyildiz A. , Karaguzel E. , Ogus E. , Surer H. , Caydere M. , Nuhoglu B. , Germiyanoglu C.
Published: October 2006

Background:  Testicular torsion is a urological emergency that requires immediate surgical intervention to prevent testicular damage. The aim of the study was to investigate the preventive effects of thiopental and propofol as anesthetics on testicular ischemia‐reperfusion injury.

Methods:  Forty male Wistar Albino rats were randomly assigned to four groups of 10 rats each. During 5 h, anesthesia was induced and maintained with thiopental in groups 1 and 2 and with propofol in groups 3 and 4. Groups 2 and 4 received left testicular ischemia (torsion) during 1 h and reperfusion (detorsion) during 4 h. Groups 1 and 3 (control groups) had no testicular torsion and detorsion. At the end of 5 h, animals were killed and both ipsilateral and contralateral testes were removed for histopathologic examination and measurement of tissue MDA (malondialdehyde) and NO (nitric oxide) levels.

Results:  In the contralateral testes of all the groups, MDA and NO measurements were not different from ipsilateral testes of the control groups. Between the groups 1 and 3, there were no differences in MDA and NO levels. Although torsion/detorsion of testes in group 4 caused significantly increased levels of tissue MDA and NO values compared with group 3, ischemia‐reperfusion in group 2 caused a further increase in these levels compared with group 4. The ipsilateral testes in the control groups did not show any morphological changes. Testicular torsion/detorsion in rats with thiopental anesthesia (group 2) caused significantly greater histopathologic injury levels than rats with propofol anesthesia (group 4).

Conclusion:  Our results suggest that propofol as an anesthetic agent may prevent testicular damage by scavenging reactive oxygen and nitrogen species and inhibiting lipid peroxidation in an animal model of testicular torsion and detorsion.
Reduction in anaesthetic drug consumption is correlated with mean titrated intra‐operative Bispectral Index values
Authors: Ellerkmann R. K. , Kreuer S. , Wilhelm W. , Röpcke H. , Hoeft A. , Bruhn J.
Published: October 2006

Background:  Several studies have shown a reduction in anaesthetic drug consumption with Bispectral Index (BIS) titration compared with standard clinical practice. However, the amount of reduction varied widely between 1% and 40%. We investigated the correlation between reduction in anaesthetic drug consumption and mean titrated BIS values.

Methods:  An analysis upon randomized controlled trials cited until January 2006 in MEDLINE and other databases investigating the potential reduction in anaesthetic (hypnotic) drug consumption with BIS titration was performed. Investigations with a marked difference (> 15%) in opioid drug consumption between the BIS group and the standard practice group were excluded. Correlations between amount of reduction in hypnotic drug use and the mean titrated BIS value were analysed with linear regression.

Results:  Fourteen manuscripts covering 2582 patients were included into the analysis. The mean BIS value in the standard clinical practice group averaged over all studies was 43.6 ± 3.2 and the mean BIS value in the BIS‐titrated group was 49.9 ± 5.4. The amount of reduction in hypnotic drug use correlated significantly with the mean BIS values in the BIS‐titrated groups (r =0.68) and with the differences between the mean BIS value in the BIS‐titrated group and the mean BIS value in the standard clinical practice group (r = 0.70). Every point of BIS difference between the two groups resulted in a reduced hypnotic drug use of approximately 2%.

Conclusion:  Despite differences in the study designs and in the drugs used, a linear correlation between the mean titrated BIS value and the hypnotic drug saving potential was found.
Forgoing life sustaining treatments: differences and similarities between North America and Europe
Authors: Moselli N. M. , Debernardi F. , Piovano F.
Published: October 2006

Background:  As evidence exist that severe neurological damage or prolonged death after inappropriate CPR could occur, restraints and indications for CPR were perceived as necessary. The objective of this review is to examine policies and attitudes towards end‐of‐life decisions in Europe and North America and to outline differences and similarities.

Methods:  A bibliographic database search from 1990 to 2006 was performed using the following terms: do‐not‐resuscitate orders, end‐of‐life decisions, withholding/withdrawal of life‐sustaining treatments, medical futility and advanced directives. Eighty‐eight articles, out of 305 examined, were analyzed and their data systematically reported and compared where possible. They consisted of studies, questionnaires and surveys answering the following questions: percentage of deaths of critical patients preceded by do‐not‐resuscitate orders, factors affecting the decision for do‐not‐resuscitate orders, people involved in this decision (patient, surrogates and medical staff) and how it was performed.

Results:  There is an evident gap between the North American use of standard and formal procedures compared with Europe. Second, they diverge in the role acknowledged to surrogates in the decisional process, as in Europe, restraints and reserves to accept surrogates as decision makers seem still strong and a paternalistic approach at the end‐of‐life is still present.

Conclusion:  Incidentally, despite the predictable differences between Europe and North America, concerns do exist about the actual extent of autonomy wished by patients and surrogates. It is important to highlight these findings, as the paternalistic attitude, too often negatively depicted, could be, according to the best medical practice, justified and more welcomed in some instances.