bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression and Characterization of a Redox-Sensing Green Fluorescent Protein (Reduction-Oxidation-Sensitive Green Fluorescent Protein) in Arabidopsis
Authors: Jiang Keni , Schwarzer Christian , Lally Elizabeth , Zhang Shibo , Ruzin Steven , Machen Terry , Remington S. James , Feldman Lewis 
Published: June 2006

Abstract
Arabidopsis (Arabidopsis thaliana) was transformed with a redox-sensing green fluorescent protein (reduction-oxidation-sensitive green fluorescent protein [roGFP]), with expression targeted to either the cytoplasm or to the mitochondria. Both the mitochondrial and cytosolic forms are oxidation-reduction sensitive, as indicated by a change in the ratio of 510 nm light (green light) emitted following alternating illumination with 410 and 474 nm light. The 410/474 fluorescence ratio is related to the redox potential (in millivolts) of the organelle, cell, or tissue. Both forms of roGFP can be reduced with dithiothreitol and oxidized with hydrogen peroxide. The average resting redox potentials for roots are −318 mV for the cytoplasm and −362 mV for the mitochondria. The elongation zone of the Arabidopsis root has a more oxidized redox status than either the root cap or meristem. Mitochondria are much better than the cytoplasm, as a whole, at buffering changes in redox. The data show that roGFP is redox sensitive in plant cells and that this sensor makes it possible to monitor, in real time, dynamic changes in redox in vivo.
SELENIUM RUBY GLASS*
Authors: Sullivan John D. , Austin Chester R. 
Published: June 2006

ABSTRACTThis paper presents the results of an experimental study on the production of selenium ruby glass, particularly on the retention of the colorants during the melting and fining operations. Selenium, cadmium, and sulfur are necessary in the final glass to get a ruby color. Reducing conditions are conducive to the retention of a large percentage of the selenium in the glass, but when conditions are highly reducing, cadmium is eliminated almost completely. The writers believe that too little attention has been given in the past to the chemistry of the entire glass batch, and as a result operators and research workers have often failed to get a ruby glass not because the loss of selenium was too high but because they eliminated the cadmium by maintaining too strongly reducing conditions.A balance must be maintained so that the batch and the atmosphere above it are sufficiently reducing to hold enough selenium in the melt but not so strongly reducing as to eliminate the cadmium.Most of the work reported in this paper was done on soda‐lime‐silica glasses similar to those melted in continuous tanks for the production of machine‐made ware. A glass of this composition, containing 0.03% of selenium, 0.06% of cadmium, and 0.03% of sulfur, will produce a ruby color. The writers have found that if the cadmium is added as cadmium sulfide the final glass will have sufficient sulfur for color development. The use of silicon as a reducing agent is suggested.An arrested‐cooling procedure for developing color is described briefly.
Thermal Expansion of Composites as Affected by the Matrix
Authors: TUMMALA R. R. , FRIEDBERG A. L. 
Published: June 2006

Summary and ConclusionsThermal expansion measurements of composite systems containing hard dispersions embedded in brittle and semibrittle matrices indicate the importance of (1) the magnitude of the stress developed in the matrix and (2) the crack propagation behavior of the matrix. The thermal expansion of these composites can be predicted if the residual stress developed as a result of the difference in the expansions of the components does not exceed a critical value defined by the modified Griffith equation. This critical stress varied considerably with the nature (brittle, semibrittle, or ductile) of the matrix.
Vapor Growth of Al2O3 Bicrystals
Authors: PARKER H. S. , HARDING C. A. 
Published: June 2006

Bicrystals containing symmetrical tilt boundaries with either theor thedirection as the rotation axis were vapor‐grown at 1740°C using the reaction 2AlCl3(g)+3CO2(g) + 3H2(g)→.Al2O3(s) + 6HCl(g) + 3CO(g). Specimens as large as 3 by 5 by 20 mm were produced in 24 h. Chemical purity of the specimens is high, with <0.1 ppm total cation impurities, as determined by activation analysis.
Compressive Creep and Hot Hardness of U‐Pu Carbides
Authors: TOKAR MICHAEL 
Published: June 2006

The compressive creep of carbides having the composition U0.79Pu0.21C1.02 and a sintered density of 11.8 g/cm3 was studied at 1300°, 1400°, and 1500°C and stresses of 2000, 4000, and 6000 psi. The equation which best fitted the data wasThe dominant creep mechanism was probably grain‐boundary sliding. The hardness of monocarbides with various U/Pu ratios was measured from room temperature to 1200°C. Probable mechanisms of deformation are discussed.
Gibbs Energy of Formation of Lead Zirconate
Authors: JACOB K. T. , SHIM W. W. 
Published: June 2006

The Gibbs energy of formation of zirconia‐saturated lead zirconate was determined by emf measurements on the solid state cells
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at 800 to 1400 K. The results obtained differ significantly from those reported in the literature based on vapor‐pressure measurements, using Knudsen effusion and transportation techniques and assuming that the vapor phase consisted entirely of monomeric PbO molecules. A reanalysis of the data obtained in the earlier vapor‐pressure studies, using mass‐spectrometric measurements on polymeric PbO species in the gas phase, gives Gibbs energies of formation of lead zirconate which are in better agreement with those obtained in this study. Recent electrochemical measurements using CaO‐ZrO2 and PbF2 solid electrolytes are in good agreement with the present study. The results obtained in this study are also consistent with the phase diagram which shows decomposition of the zirconate to tetragonal zirconia and a liquid phase rich in PbO at 1843 K.
Widespread axonal damage in the brain of drug abusers as evidenced by accumulation of β‐amyloid precursor protein (β‐APP): an immunohistochemical investigation
Authors: Büttner Andreas , Rohrmoser Katharina , Mall Gita , Penning Randolph , Weis Serge 
Published: June 2006

ABSTRACTBackground  In drug abusers, white matter changes have been described by neuroimaging analyses in different brain regions. A specific pattern of involvement or a predominance of a specific brain region could not be drawn.Aims  To examine alterations of the white matter as a possible morphological substrate of the neuroimaging findings.Methods  Brain specimens of 30 polydrug abusers and 20 controls were obtained at autopsy. The white matter from 11 different brain regions was analysed by means of immunohistochemistry for β‐amyloid precursor protein (β‐APP), a marker of axonal damage.Findings  In the white matter of polydrug abusers, β‐APP‐immunopositive accumulations were increased significantly compared to controls. They were more prominent in the brains of younger drug abusers than in those of the elderly. With the exception of five cases (four polydrug abusers and one control case), there were no significant white matter changes seen on myelin‐stained sections, but there was a concomitant microglial activation.Conclusions  Our results show a significant axonal damage in the brains of polydrug abusers, which might represent the morphological substrate of a chronic‐progressive drug‐induced toxic‐metabolic process. It is yet to be established if the observed changes are responsible for the alterations seen in different neuroimaging analyses and which drugs of abuse might be of major pathogenetic significance.
A defect in nir1, a nirA‐like transcription factor, confers morphological abnormalities and loss of pathogenicity in Colletotrichum acutatum
Authors: HOROWITZ SIGAL , FREEMAN STANLEY , ZVEIBIL AIDA , YARDEN ODED 
Published: June 2006

SUMMARYA non‐pathogenic mutant of Colletotrichum acutatum, designated Ca5, exhibited epiphytic hyphal growth and did not cause lesions on strawberry plants but grew necrotrophically when inoculated directly onto wounded stolons. In the absence of an external nitrogen source, the mutant exhibited extended germ‐tube growth prior to appressorium formation. The deduced product of the impaired gene (nir1) is similar to NirA, an Aspergillus nidulans transcriptional regulator of nitrogen metabolism. Inoculation of leaves with wild‐type or Ca5 conidia in the presence of a preferred nitrogen source resulted in massive epiphytic hyphal production, appressorium formation and rapid symptom development. Expression of C. acutatum wild‐type nitrate reductase (nit1) and glutamine synthetase (gln1) was induced by nitrate but only nit1 expression was repressed in a rich medium. nit1 transcription increased during the appressorium‐production stage, indicating that nitrogen starvation constitutes a cue for the regulation of appressorium development. The presence of nit1 transcript during various phases of infection is indicative of partial nitrogen starvation in planta. cAMP‐dependent protein kinase A (PKA) was determined to be a negative regulator of immediate post‐germination appressoria formation in the wild‐type. As inhibition of PKA activity in the nir1 mutant did not affect appressoria formation, we suggest that NIR1 acts either in parallel or downstream of the PKA pathway. Our results show that nir1 is a pathogenicity determinant and a regulator of pre‐infection development under nitrogen‐starvation conditions and that nitrogen availability is a significant factor in the pre‐penetration phase.
Major histocompatibility complex class I expression in human tonsillar and laryngeal epithelium
Authors: Hobbs C G L , Rees L E N , Heyderman R S , Birchall M A , Bailey M 
Published: June 2006

Summary
Understanding the immunological structure of the upper aerodigestive tract is important for analysing the interaction between incident challenges, such as human papillomavirus infection, and disease, particularly head and neck cancer. We have shown previously that tonsillar and laryngeal epithelium express major histocompatibility complex (MHC) class II locus products, but that expression of human leucocyte antigen (HLA)-DQ is reduced compared to HLA-DR. This may confer a decreased repertoire of presented T cell epitopes generated by the processing of exogenous peptides in upper airway mucosa. To determine whether the peptide repertoire presented by MHC class I loci varies in stratified squamous epithelium, laryngeal and tonsillar biopsies were taken from 19 otherwise healthy patients (M : F 6 : 13, 16–64 years). Quantitative immunofluorescence microscopy, using antibodies to MHC class I α-chain (pan-locus specific, HLA-A, HLA-B + C) and β2-microglobulin, showed lower expression of the α-chain in laryngeal and tonsillar epithelium than in either lamina propria (tonsil 73%versus 89%, P &lt; 0·0001; larynx 68%versus 85%, P &lt; 0·005). Within the epithelium itself, the intensity of α-chain expression decreased from the basal to apical layers. In paired squamous epithelia from the two sites, α-chain expression was significantly higher in the tonsil compared to the larynx (79%versus 62%, P &lt; 0·05). We suggest that these findings reflect functional stratification of these epithelia with the superficial layer, most exposed to incident challenges, less equipped to present antigens to conventional T cells. This may affect immunosurveillance directed at viral and tumour-related epitopes in the upper airway.
Toll-like receptor (TLR) 4 polymorphism Asp299Gly is not associated with disease course in Dutch sarcoidosis patients
Authors: Veltkamp M , Grutters J C , Van Moorsel C H M , Ruven H J T , Van Den Bosch J M M 
Published: June 2006

Summary
The aetiology of sarcoidosis, a systemic disorder characterized by the formation of non-caseating granulomas in variable organs, remains enigmatic. Clarification is hampered by heterogeneity in disease phenotypes and course, due partly to the influence of a variety of genetic and environmental factors. Multiple studies have pointed towards bacteria as possible causative agents. Toll-like receptors (TLR) are innate immunity receptors important in the immune response against pathogens. TLR-4, together with CD14 and MD-2, is an essential receptor for the recognition of lipopolysaccharide (LPS), unique to the cell wall of Gram-negative bacteria. Recently, an association between TLR-4 polymorphism Asp299Gly, leading to a change in the extracellular domain of the receptor and possible hyporesponsiveness to LPS, and a chronic course of sarcoidosis was found in German patients. In the present study this polymorphism was genotyped in 156 Dutch sarcoidosis patients and 200 healthy Dutch controls using dual-labelled fluorescent oligonucleotides. No differences were found in allelic distributions between patients and controls (P = 0·79) or within the different clinical entities of the sarcoidosis group (P = 0·44). Importantly, there were no differences between the Dutch and German sarcoidosis patients (P = 0·62). However, the allelic distribution of the Asp299Gly polymorphism differed significantly between both control groups (P = 0·04). This study highlights the importance of testing a reported gene association in a distinct population when performing genetic association studies.
EilA, a HilA‐like regulator in enteroaggregative Escherichia coli
Authors: Sheikh Jalaluddin , Dudley Edward G. , Sui Baoquan , Tamboura Boubou , Suleman Altaf , Nataro James P. 
Published: June 2006

SummaryEnteroaggregative Escherichia coli (EAEC) is increasingly recognized as a diarrhoeal pathogen in developing and industrialized countries. Most EAEC virulence factors thus far described are encoded on virulence plasmid pAA, yet recent completion of the EAEC genome has suggested the presence of additional factors encoded on chromosomal islands. Previous reports have recognized the presence of a type III secretion system (T3SS), designated ETT2, at the glyU locus of prototype EAEC strain 042, along with possible T3SS effectors at the selC locus. The selC locus was also noted to harbour homologues of Salmonella enterica regulator HilA and of invasin from Yersinia spp., yet previous publications suggested that these loci may be silent. Here, we show that the genes of the selC locus are present inconsistently among a collection of well‐characterized EAEC strains. Notably, however, there was perfect correlation between the presence of hilA‐homologue eilA and predicted Yersinia invasin homologue gene eaeX. We hypothesized that if expressed, the putative gene product EilA would contribute to EAEC virulence in part by activation of the T3SS and its effectors. An eilA mutant was constructed in EAEC strain 042, and complementation was achieved by cloning the eilA gene under control of an arabinose‐dependent promoter. In this system, we observed expression of at least seven genes to be affected by expression of eilA, either directly or indirectly: selC locus genes eipB, eipC, eipD, eicA and eaeX (renamed here air), as well as glyU ETT2 genes eivF and eivA. Notably, the eilA mutant was shown to be less adherent to epithelial cells in culture and to form less abundant biofilms than the isogenic parent. These effects were recapitulated in the air mutant, suggesting that the predicted outer membrane protein product of the air gene is involved as an accessory adhesin and aggregin of EAEC, coexpressed with the T3SS. Our data suggest that the T3SS of EAEC and presumed effectors located on different chromosomal islands may be coordinately activated by EilA, which also activates the genetically linked high molecular weight bacterial surface protein Air. Contributions of this new putative virulence‐related regulon in EAEC may include adherence, aggregation, and as yet uncharacterized roles for the T3SS.
Characterization and functional analysis of phosphoenolpyruvate carboxylase kinase genes in rice
Authors: Fukayama Hiroshi , Tamai Tesshu , Taniguchi Yojiro , Sullivan Stuart , Miyao Mitsue , Nimmo Hugh G. 
Published: June 2006

SummaryPhosphoenolpyruvate carboxylase (PEPC), a key enzyme of primary metabolism of higher plants, is regulated by reversible phosphorylation, which is catalyzed by PEPC kinase (PPCK). Rice has three functional PPCK genes, OsPPCK1, OsPPCK2 and OsPPCK3, all of which have an intron close to the 3′ end of the coding region. A novel control mechanism was found for expression of OsPPCK2, namely alternative transcription initiation, and two different transcripts were detected. The four different transcripts of the OsPPCK genes showed different expression patterns. While OsPPCK1 and OsPPCK3 were highly expressed in roots and at low levels in other organs, the two OsPPCK2 transcripts were expressed in all organs. OsPPCK3 was expressed mostly at night, while the long OsPPCK2 transcripts were present in the leaves only in the daytime. Nitrate supplementation of leaves selectively induced expression of both OsPPCK2 transcripts, while phosphate starvation only induced the shorter one. Such diverse expression patterns of OsPPCK genes suggest the importance and variety of strict activity regulation of PEPC in rice. From the correlation between gene expression and the phosphorylation level of PEPC, which was monitored as that of the maize PEPC expressed in transgenic rice plants, it was concluded that the short OsPPCK2 transcripts were expressed in rice leaf mesophyll cells upon nitrogen supplementation and phosphate starvation, whereas OsPPCK3 participated in the nocturnal phosphorylation of PEPC in these cells. Expression of PPCK proteins in rice leaves was detected by immunoblotting using a specific antiserum, and the expression of two different OsPPCK2 proteins derived from alternative transcription initiation was confirmed.
Prediction of large esophageal varices in patients with cirrhosis of the liver using clinical, laboratory and imaging parameters
Authors: Sharma Sanjay Kumar , Aggarwal Rakesh 
Published: June 2006

AbstractBackground:  It is currently recommended that all patients with liver cirrhosis undergo upper gastrointestinal endoscopy (UGIE) to identify those who have large esophageal varices (LEVx) that carry a high risk of bleeding and may benefit from prophylactic measures. This approach leads to unnecessary UGIE in those without LEVx. We tried to identify clinical, laboratory and imaging parameters that may predict the presence of LEVx and help select patients for UGIE.Methods:  This prospective study included newly diagnosed patients with cirrhosis and no history of gastrointestinal bleeding scheduled to undergo UGIE. Patients underwent detailed clinical examination, blood tests (hematology, liver function tests) and ultrasonography. Size of esophageal varices was assessed at UGIE; Paquet’s grades 0‐II were classified as small varices, and III‐IV as LEVx. Association of LEVx with qualitative and quantitative parameters was studied using χ2 and Mann–Whitney U‐tests, respectively. Parameters found to be significant were tested in a forward‐conditional multivariate logistic regression analysis to identify independent predictors. Receiver operating characteristic curve analysis was used to assess the efficacy of prediction models.Results:  Of the 101 patients (median age 45; range 15–74 years; 87 male; Child‐Pugh class: A 18, B 31, C 52), 46 had LEVx. On univariate analysis, five variables were significantly associated with the presence of LEVx. These included pallor (P = 0.026), palpable spleen (P = 0.009), platelet count (P < 0.002), total leukocyte count (P < 0.0004) and liver span on ultrasound (P = 0.031). On multivariate analysis, two of these parameters, namely low platelet count and presence of palpable spleen, were found to be independent predictors of the presence of LEVx. A receiver‐operating characteristics curve using the predictor function arrived at from this analysis had an area under the curve of 0.760.Conclusion:  Presence of palpable spleen and low platelet count are independent predictors of presence of LEVx in patients with cirrhosis. Use of these parameters may help identify patients with a low probability of LEVx who may not need UGIE. This may help reduce costs and discomfort for these patients and the burden on endoscopy units.
The perturbation method and the extended finite element method. An application to fracture mechanics problems
Authors: GRASA J. , BEA J. A. , RODRÍGUEZ J. F. , DOBLARÉ M. 
Published: June 2006

ABSTRACTThe extended finite element method has been successful in the numerical simulation of fracture mechanics problems. With this methodology, different to the conventional finite element method, discretization of the domain with a mesh adapted to the geometry of the discontinuity is not required. On the other hand, in traditional fracture mechanics all variables have been considered to be deterministic (uniquely defined by a given numerical value). However, the uncertainty associated with these variables (external loads, geometry and material properties, among others) it is well known. This paper presents a novel application of the perturbation method along with the extended finite element method to treat these uncertainties. The methodology has been implemented in a commercial software and results are compared with those obtained by means of a Monte Carlo simulation.
The Community Links of a Sample of People with Intellectual Disabilities
Authors: Hall Louise , Hewson Simon 
Published: June 2006

Background  In 1995, an unpublished study (S. Hewson & C. Waters) showed that the community links of residents in 11 local National Health Services (NHS) trust houses were meagre, despite the service's stated commitment to community presence and participation. The 1995 study was repeated for the same 11 houses in 2002 to examine whether any changes had occurred.Method  A test–retest design, with repeated measures was used, involving, as closely as possible, the same participants at two time points. Community links referred to the time residents spent outside their house, and the time unpaid visitors spent inside the house in the presence of the residents.Results  The community links of the people studied were no better in 2002 than in 1995.Conclusions  These findings question whether current service provision can deliver policy objectives for social inclusion for people with intellectual disabilities.