bluuebunny/crossref_metadata_2025 huggingface dataset:
Color Stability of Dry Earth Pigmented Maxillofacial Silicone A‐2186 Subjected to Microwave Energy Exposure
Authors: Kiat‐amnuay Sudarat , Johnston Dennis A. , Powers John M. , Jacob Rhonda F.
Published: July 2005

Purpose:
The purpose of this study was to measure spectrophotometrically the color stability of pigmented A‐2186 silicone maxillofacial elastomer with 10% by volume of titanium white dry earth opacifier before and after exposure to microwave energy over a simulated 1.5‐year period of microwave sterilization.

Materials and Methods:
A‐2186 silicone elastomer opacified with titanium white dry earth pigment, pigmented with 5 cosmetic dry earth pigment colors [no pigment (control) group (Pc), red (Pr), yellow ochre (Py), burnt sienna (Po), and a mixture of Pr + Py + Po color group (P3)], was used in this study. Each of the 5 experimental groups consisted of 5 specimens. All specimens were placed in a 250 ml glass beaker filled with 150 ml of water (replenished for each microwave exposure). An exposure of 6 minutes was used 18 times (simulating 1.5 years of microwave sterilization with one 6 minute exposure monthly). Reflectance values were measured by spectrophotometer. Three‐ and two‐way analyses of variance with repeated measures were performed for the color difference (ΔE*) with the factors of group/color/months, and group/months, respectively. Means were compared by Tukey Honest Significant Difference (HSD) multiple range test calculated at the 0.05 level of significance using SPSS.

Results:
The trained human eye can detect color changes (ΔE*) greater than 1.0. Most ΔE* values of the red pigment group at all intervals and the mixed pigment group at 15‐ and 18‐ month intervals increased significantly greater than 1.0 (p < 0.001) compared with the control group. Yellow and burnt sienna groups remained the most color stable over time with ΔE* values below 0.35.

Conclusions:
Lack of color stability of red dry earth pigmented A‐2186 silicone maxillofacial elastomers was clinically significant after 12‐month exposure to microwave energy as compared with yellow, burnt sienna, and opacified A‐2186 dry earth pigments
Shear Bond Strengths of Two Composite Core Materials After Using All‐in‐One and Single‐Bottle Dentin Adhesives
Authors: Sen Deniz , Akgüngör Gökhan
Published: July 2005

Purpose:
The purpose of this study was to compare the shear bond strengths of 2 composite core materials after using all‐in‐one and single‐bottle dentin bonding materials.

Material and methods:
The occlusal surfaces of 100 extracted, intact human third molars were ground to expose a flattened area of dentin and polished with 600‐grit silicon carbide paper. Specimens were divided into 5 main groups (n= 20). Three all‐in‐one (AQ Bond, One‐Up Bond, Xeno‐CF Bond) and 2 single‐bottle adhesives (Single Bond, One‐Step Plus) were used. Each group was further divided into 2 subgroups. Ti‐Core and Built‐it F.R. core materials were applied using a translucent plastic ring (diameter: 3 mm, height: 5 mm). After storage in 37°C water for 24 hours, shear bond strengths were measured using a Universal testing machine with a crosshead speed of 0.5 mm/min. Debonded dentin surfaces were examined with SEM. Two‐way analysis of variance (ANOVA) and multiple comparison (Tukey) tests were used for statistical analysis of data.

Results:
Two‐way ANOVA revealed that the type of core material did not significantly influence the shear bond strength (p > 0.05), whereas there were significant differences in shear bond strength among the types of bonding agents (p < 0.0001). Shear bond strengths for single‐bottle adhesive systems were significantly higher than those for all‐in‐one adhesive systems (p < 0.05). Furthermore, the interaction of these 2 parameters was not significant (p > 0.05). The fracture modes were predominantly adhesive for all‐in‐one adhesives and cohesive for single‐bottle adhesives.

Conclusion:
Bonding of composite core materials with the newly developed all‐in‐one dentin adhesives produced lower shear bond strengths as compared with single‐bottle adhesives.
Phylogenetic Analyses of Small Subunit Ribosomal RNA Coding Regions Reveal a Monophyletic Lineage of Euglyphid Testate Amoebae (Order Euglyphida)
Authors: WYLEZICH CLAUDIA , MEISTERFELD RALF , MEISTERFELD SUSANNE , SCHLEGEL MARTIN
Published: July 2005

ABSTRACT. The Testaceafilosia includes amoebae with filopodia and with a proteinaceous, agglutinated or siliceous test. To explore the deeper phylogeny of this group, we sequenced the small subunit ribosomal RNA coding region of 13 species, including the first sequence of an amoeba with an agglutinated test, Pseudodifflugia sp. Phylogenetic analyses using maximum parsimony and maximum likelihood methods as well as neighbor joining method yielded the following results: the order Euglyphida forms a monophyletic lineage with the sarcomonads as sister group. The next related taxa are the Chlorarachnea and the unidentified filose strain N‐Por. In agreement with the previous studies the Phytomyxea branch off at the base of this lineage. The Monadofilosa (Testaceafilosia and Sarcomonadea) appear monophyletic. The Testaceafilosia are polyphyletic, because Pseudodifflugia sp. is positioned as the sister taxon to the sarcomonads. Within the order Euglyphida Paulinella branches off first, together with Cyphoderia followed by Tracheleuglypha. In maximum likelihood and neighbor joining analyses, the genus Euglypha is monophyletic. The branching pattern within the order Euglyphida reflects the evolution of shell morphology from simple to complex built test.
New Species of Balantidium and Pamcichttdotherus (Ciliophora) Inhabiting the Intestines of Four Surgeonfish Species from the Tuvalu Islands, Pacific Ocean
Authors: GRIM J. NORMAN , CLEMENTS KENDALL D. , BYFIELD TAMSEN
Published: July 2005

ABSTRACT. Four species of adult herbivorous surgeonfishes (Family Acanthuridae) were collected from the remote South‐Pacific island system of Tuvalu. Their intestinal contents were examined, and of four populations of ciliated protists, two new species were discovered and are described. Ciliates were examined after protargol staining and, in some cases, scanning electron microscopy. Members of each population were examined and 10 characters measured for the balantidia, and 13 for the paracichlidotherids. A new Balantidium is described which has an unusually large dextr‐oral field of cilia. A new species of Paracichlidotherus was discovered which has a macronucleus significantly smaller and well anteriad the cytoplasmic portion of the oral polykinetids relative to the type species.
Cattle Pathogen Tritrichomonas foetus (Riedmüller, 1928) and Pig Commensal Tritrichomonas suis (Gruby & Delafond, 1843) Belong to the Same Species
Authors: TACHEZY JAN , TACHEZY RUTH , HAMPL VLADIMÍR , ŠEDINOVÁ MIROSLAVA , VAŇÁČOVÁ ŠTĚPÁNKA , VRLÍK MARTIN , VAN RANST MARC , FLEGR JAROSLAV , KULDA JAROSLAV
Published: July 2005

ABSTRACT. A number of reports suggest that the sexually transmitted pathogen of cattle, Tritrichomonas foetus, and a gastrointestinal commensal of pigs, Tritrichomonas suis, are very similar and may be co‐specific. A conclusive review of the taxonomic and nomenclatural status of these species has not been presented so far. Toward this end, we reexamined and compared porcine and bovine trichomonads with regard to their morphology, pathogenic potential, and DNA polymorphism. Using light and electron microscopy, no distinguishing features between T. foetus and T. suis strains were found in size, general morphology, and karyomastigont structure. Both bovine and porcine trichomonads showed pathogenic potential in the subcutaneous mouse assays and did not separate into distinct groups according to strain virulence. Three DNA fingerprinting methods (i.e. RFLP, RAPD, and PCR‐based analysis of variable‐length DNA repeats) that produce species‐specific DNA fragment patterns did not distinguish between the bovine and porcine strains. Sequencing of a variable 502‐bp DNA fragment as well as comparison of 16S rRNA gene sequences did not reveal species‐specific differences between the cattle and porcine strains. Therefore, we conclude that T. foetus and T. suis belong to the same species. To prevent confusion that may arise from T. foetus‐T. suis synonymy, we propose to suppress the older name suis and maintain its accustomed junior synonym foetus as a nomen protection for both cattle and porcine trichomonads. The case has been submitted to the International Commision on Zoological Nomenclature for ruling under its plenary power.
Changes in Host and Parasite‐Derived Cellular and Extracellular Matrix Components in Developing Cysts of Myxobolus pendula (Myxozoa)
Authors: MARTYN AMANDA A. , HONG HENRY , RINGUETTE MAURICE J. , DESSER SHERWIN S.
Published: July 2005

ABSTRACT. Cysts of Myxobolus pendula from the gill arch of creek chub (Semotilus atromaculatus) were examined at various stages of development using light and electron microscopy. The subepithelial host connective tissue underwent dramatic changes, including degradation and remodelling of collagen and vascularisation, in response to the infection. Inflammatory cells lay in a fluid‐filled space beneath the host's connective tissue and surrounded a distinctive parasite‐derived matrix, composed of collagen fibril bundles embedded in cellular processes of the underlying secretory cells. This collagen matrix was resistant to degradation and invasion by leukocytes. Secretion of a matrix by M. pendula as a structural support, and a protective barrier against the host inflammatory cells is a novel observation for cyst‐forming Myxosporea.
Direct Visualization of the Microtubular Cytoskeleton of Ciliated Protozoa with a Fluorescent Taxoid
Authors: ARREGUI LUCÍA , MUÑOZ‐FONTELA CESAR , SERRANO SUSANA , BARASOAIN ISABEL , GUINEA ALMUDENA
Published: July 2005

ABSTRACT. Visualization of the infraciliature, which is an essential tool for the identification of ciliate species, has traditionally been obtained with silver proteinate methods. Since infraciliature is mainly composed of microtubules, we used the synthetic fluorescent taxoid FLUTAX as a method for ciliate identification. The main advantages of this method are the facility and rapidity of its application and the fact that no previous fixation and permeabilization processes are required. FLUTAX may also be used as a probe to follow morphogenetical changes in the microtubular cytoskeleton during the ciliate life cycle.
Redescription of Strombidium oculatum Gruber 1884 (Ciliophora, Oligotrichia)
Authors: MONTAGNES DAVID J. S. , LOWE CHRIS D. , POULTON ALEX , JONSSON PER R.
Published: July 2005

ABSTRACT. The marine, tide pool‐dwelling ciliate Stombidium oculatum was redescribed using live, stained, SEM, and TEM material prepared from samples collected from pools on the Isle of Man (Irish Sea) and Brittany (France). Also, we reviewed the older German and French works that reported on ciliates collected in the Mediterranean and Brittany, respectively. The Brittany and Isle of Man populations of the ciliate were considered identical. Some morphological and behavioural differences exist between the Brittany‐Isle of Man populations and the Mediterranean populations, but they were insufficient to distinguish different taxa. Thus, taxa from all three locations were considered to be conspecific. Key features used to describe the ciliate were+morphology and ultrastructure of the free‐swimming ciliate; cyst morphology; presence of mixotrophic‐chloroplasts; presence of an eye spot composed of stigma obtained from chlorophyte prey; division, morphogenesis, and nuclear structure; live observations and behaviour, including the encystment‐excystment cycle. Based on morphological and behavioural characteristics the taxon was distinguished from other similar species, and a neotype has been designated as no type material exists.
A New Species in the Genus Cyrtostrombidium (Ciliophora, Oligotrichia, Oligotrichida)+its Morphology, Seasonal Cycle and Resting Stage
Authors: KIM YOUNG‐OK , SUZUKI TOSHIKAZU , TANIGUCHI AKIRA
Published: July 2005

ABSTRACT. Cysts of an oligotrich ciliate were collected from natural sediment samples in Onagawa Bay, northeastern coast of Japan, and examined for their excystment capability. A high excystment ratio was obtained at lower temperatures of 10 or 15°C; no excystment occurred at 20°C. Excysted vegetative cells were observed after protargol staining and were identified as a new species, Cyrtostrombidium boreale n. sp. The seasonal changes in the vegetative population and sedimentation of newly formed cysts were also investigated in situ. Planktonic vegetative cells were abundant during the cold season from February to May, when the water temperature was lower than 10°C. Mass encystment occurred abruptly just after the seasonal peak of the vegetative population in April. These results indicate that C. boreale is a cold‐water species and aestivates during the longer, warm period from late spring to fall.
A Model of Biocomplexity and its Application to the Analysis of Some Terrestrial and Marsh Eukaryotic Microbial Communities with an Emphasis on Amoeboid Protists
Authors: ANDERSON O. ROGER
Published: July 2005

ABSTRACT. Biocomplexity theory has become increasingly important in understanding ecosystem dynamics as we realize that the interactions among subunits in a multi‐component system often produce elaborate states that are not easily explained in terms of the individual parts of the system. A Euclidean geometric model of biocomplexity is presented and illustrated using protistan communities. The model is based on three quantitative biotic dimensions (indices) for small subsamples (0.01 g) taken from each sample core of substratum; (1) richness of morphospecies expressed as mean count per 0.01 g, (2) spatial diversity of protists expressed as the number of unique morphospecies (i.e. those occurring in only one of the 0.01‐g subsamples and not in any of the other subsamples), and (3) patchiness (non‐uniform aggregation) of the distribution of protists across the 0.01‐g subsamples. These three indices are mapped into a three‐dimensional Euclidean space model, and the position of each point and its geometric distance from the origin are used as a general index of biocomplexity. The usefulness of the model is illustrated by applying it to a range of terrestrial and marsh communities. Within the set of 15 samples examined in this study, the marsh rhizosphere samples are among the most complex.
Presence of Glyoxylate Cycle Enzymes in the Mitochondria of Euglena gracilis
Authors: ONO KOUKI , KONDO MAKI , OSAFUNE TETSUAKI , MIYATAKE KAZUTAKA , INUI HIROSHI , KITAOKA SHOZABURO , NISHIMURA MIKIO , NAKANO YOSHIHISA
Published: July 2005

ABSTRACT. Isocitrate lyase and malate synthase are specific enzymes of the glyoxylate cycle, used here as glyoxysomal markers. Both enzymes were found in the mitochondrial fraction after organelle fractionation by isopycnic centrifugation. Electron microscopy of this fraction indicated that mitochondria were the only recognizable organelles. Using an immunogold labeling method with anti‐(malate synthase) antiserum, the only organelles stained in cells were the mitochondria. These results show that the glyoxylate cycle is present in mitochondria in Euglena.
Screening of Substrate Analogs as Potential Enzyme Inhibitors for the Arginine Kinase of Trypanosoma cruzi
Authors: PEREIRA CLAUDIO A. , ALONSO GUILLERMO D. , IVAUDI SOLEDAD , BOUVIER LEÓN A. , TORRES HÉCTOR N. , FLAWIÁ MIRTHA M.
Published: July 2005

ABSTRACT. Arginine kinase catalyzes the transphosphorylation between phosphoarginine and ADP. Phosphoarginine is involved in temporal ATP buffering and inorganic phosphate regulation. Trypanosoma cruzi arginine kinase phosphorylates only L‐arginine (specific activity 398.9 mUE‐min−1 mg−1), and is inhibited by the arginine analogs, agmatine, canavanine, nitroarginine, and homoarginine. Canavanine and homoarginine also produce a significant inhibition of the epimastigote culture growth (79.7% and 55.8%, respectively). Inhibition constants were calculated for canavanine and homoarginine (7.55 and 6.02 mM, respectively). In addition, two novel guanidino kinase activities were detected in the epimastigote soluble extract. The development of the arginine kinase inhibitors of T. cruzi could be an important feature because the phosphagens biosynthetic pathway in trypanosomatids is different from the one in their mammalian hosts.
Identification, Cloning, and Characterization of Microsatellite DNA in Euglena gracilis
Authors: ZHANG WEN‐JING , YANG JUN , YU YU‐HE , SHEN YUN‐FEN
Published: July 2005

Abstract. Microsatellite DNA has been developed into one of the most popular genetic markers. We have identified and cloned microsatellite loci in the genome of a free‐living protozoan Euglena gracilis FACHB‐848, using the random amplified microsatellites method (RAMS). The digoxigenin‐labelled oligonucleotides (CT)10 and (GT)10 served as probes to detect complementary sequences in the randomly amplified polymorphic DNA (RAPD) fingerprints produced by means of Southern blotting. Subsequently, positive RAPD fragments were cloned. From a total of 31 RAPD primer profiles, eight microsatellite loci of E. gracilis were detected and characterized. Further, six sites (i.e. EGMS1, EGMS3, EGMS4, EGMS5, EGMS6, and EGMS7) showed polymorphisms. We found a GT or CT microsatellite every 10.5 kb in the genome of E. gracilis, and similar to animal genomes, the (GT)n motif was much more abundant than the (CT)n motif. These polymorphic microsatellite DNA will serve as advantageous molecular markers for studying the genetic diversity and molecular ecology of Euglena.
Inhibitors of tyrosine kinase inhibit the production of urokinase plasminogen activator in human prostatic cancer cells
Authors: SKOGSETH HAAKON , LARSSON ERIK , HALGUNSET JOSTEIN
Published: July 2005

Urokinase‐type plasminogen activator (uPA) seems to be an important protease in prostate cancer invasion, and tyrosine phosphorylation is thought to play a role in the regulation of its production. The amount of uPA was measured with a synthetic peptide substrate after treatment with various concentrations of tyrosine kinase inhibitors (TKI). The effect on proliferation and apoptosis was also assayed. Non‐toxic levels of genistein or the tyrphostin AG 490 produced up to 50% reduction of the uPA production in PC‐3 and DU‐145. The tyrphostins AG 1296 and AG 1478 inhibited uPA production in PC‐3 cells, whereas DU‐145 showed a slight increase of uPA production. TKI neither induced any detectable apoptosis, nor was there any reduction in proliferation rate. TKI can profoundly modify the production of uPA in prostatic cancer cells, thus indicating their possible use as suppressors of the invasive phenotype. The therapeutic potential of TKI warrants further investigation.
The area of the tidemark in osteoarthritis – a three‐dimensional stereological study in 21 patients
Authors: BONDE H. V. , TALMAN M. L. M. , KOFOED H.
Published: July 2005

We investigated the area of the tidemark in osteoarthritic and normal cartilage by stereology as well as the number of vessels penetrating the tidemark. The area of the tidemark was significantly increased in osteoarthritis, as was the number of vessels penetrating the tidemark. These three‐dimensional findings are new compared to previous two‐dimensional findings where it has been discussed whether there were any differences between osteoarthritic cartilage and normal cartilage with respect to duplications of the tidemark and vascularisation. The present findings using stereology may erase the uncertainty of previous findings, and support the hypothesis that primary osteoarthritis is partly of vascular origin.
Usefulness and limitations of ultrasound‐guided core biopsy in the diagnosis of musculoskeletal tumours
Authors: LÓPEZ JOSÉ I. , DEL CURA JOSÉ L. , ZABALA ROSA , BILBAO FRANCISCO J.
Published: July 2005

Ultrasound‐guided needle biopsy is a safe and efficient diagnostic method increasingly used in the initial approach to superficial and deep musculoskeletal tumours. However, so far no general consensus has been reached regarding its reliability. During a 6‐year period (1999–2004), biopsies were taken from 188 patients (100 females, 88 males; age average 55.8 years) with musculoskeletal tumours under ultrasound guidance using 18G BioPince® or 14G ProMag® 2.2 true‐cut type needles. Cytological (imprints and cytocentrifugates) and histological material was obtained for diagnosis in every case. The lower extremity (59 cases) and the abdominal wall (29 cases) were the most commonly affected sites. Benign/reactive tumours (77 cases), metastatic epithelial malignancies (40 cases), and sarcomas (36 cases) were most frequently diagnosed. In 180 (95.75%) cases, core needle results were concordant with the definitive diagnosis (97 true positives and 83 true negatives). Relevant diagnostic discordance was seen in 8 (4.25%) cases (8 false negatives and 0 false positives). Sensitivity, specificity and positive and negative predictive values were 92%, 100%, 100%, and 91%, respectively. Ultrasound‐guided core biopsy is thus a useful method in the initial approach to musculoskeletal tumours that allows correct patient management in the vast majority of cases.
Tumour Necrosis Factor Receptor 1 and Hepatocyte Regeneration in Acetaminophen Toxicity: A Kinetic Study of Proliferating Cell Nuclear Antigen and Cytokine Expression
Authors: James Laura P. , Kurten Richard C. , Lamps Laura W. , McCullough Sandra , Hinson Jack A.
Published: July 2005

Abstract: To determine the importance of tumour necrosis factor receptor 1 in hepatocyte regeneration in acetaminophen toxicity, wild type and tumour necrosis factor receptor 1 knock‐out mice were dosed with acetaminophen (300 mg/kg intraperitoneally) and sacrificed at 4, 24, 48, 72, and 96 hr. Biochemical parameters (alanine aminotransferase, ALT) and histologic evidence of hepatocellular injury were comparable in the two groups of mice. To examine the effects of tumour necrosis factor receptor 1 on hepatocyte regeneration, immunohistochemical staining with proliferating cell nuclear antigen was performed. Immunohistochemical staining for proliferating cell nuclear antigen was significantly reduced at multiple time points in the knock‐out mice and did not normalize until 96 hr. To evaluate the effect of tumour necrosis factor receptor 1 depletion on cytokines known to be involved in regeneration, levels of macrophage inhibitory protein 2, interferon‐γ‐inducible protein‐10 and monocyte chemoattractant protein 1 were compared in the two groups of mice. Significant elevation of all cytokines was observed in both groups of mice; however, higher levels were present in the knock‐out mice. Depletion of tumour necrosis factor receptor 1 has long‐lasting effects on hepatocyte regeneration in acetaminophen toxicity but multiple other factors appear to orchestrate eventual recovery in these mice.
Long‐Term Parathyroid‐ and c‐Cell Function after Radioiodine for Benign Thyroid Diseases
Authors: Mortensen Lene S. , Smidt Kamille , Jørgensen Anette , Nielsen Jørn Theil , Laurberg Peter , Søndergaard Liselotte , Rungby Jørgen
Published: July 2005

Abstract: The study examined static and dynamic parathyroid hormone and calcitonin secretion after radioiodine, and was a retrospective study of patients having received radioiodine for benign conditions 8–12 years earlier. In one group of patients parathyroid hormone and calcium were measured as single blood tests, in a second group of patients parathyroid hormone and calcitonin secretion capacity were measured during a hypocalcaemic citrate‐clamp and a hypercalcaemic stimulation test. Baseline calcium and parathyroid hormone were normal within expected ranges 8–12 years after radioiodine. Stimulated parathyroid hormone or calcitonin secretion did not differ from an age‐ and gender‐matched control group. Radioiodine in doses used for benign thyroid diseases appears safe with regard to parathyroid hormone and calcitonin secretion.
The Superoxide Dismutase Mimetic, Tempol, Reduces the Bioavailability of Nitric Oxide and does not Alter L‐NAME‐Induced Hypertension in Rats
Authors: Preti Silvio César , Da Cunha Valdeci , Vassallo Dalton Valentim , Stefanon Ivanita
Published: July 2005

Abstract: L‐NAME‐induced hypertension is characterized by chronic inhibition of nitric oxide synthesis. We have investigated if tempol, an agent mimicking superoxide dismutase might reduce hypertension and the increased vascular reactivity to pressor agents. Rats were divided into: Control, animals receiving L‐NAME 50 mg kg−1day−1, tempol 200 mg kg−1day−1 and tempol plus L‐NAME. Drugs were administrated in the drinking water for seven days. L‐NAME increased mean arterial blood pressure (Control: 108±3 mmHg versus L‐NAME 181±5 mmHg; P<0.05). Tempol did not change arterial pressure and heart rate in L‐NAME and Control groups. The reactivity to phenylephrine increased in the L‐NAME group (Emax Control: 2.00±0.15 g versus L‐NAME: 2.45±0.14 g); tempol+L‐NAME (Emax: 2.55±0.15 g) and in the tempol group (Emax: 2.57±0.14 g). Maximal relaxation induced by acetylcholine was reduced in L‐NAME group (60.9±3%) and tempol+L‐NAME (37.4±6%) compared to Control (99.1±0.12%) and tempol groups (95.6±2.12%). All treated groups presented a reduction in the effects of L‐NAME administration on basal vascular tone. Our results show that tempol, in the dose used in this study, did not change the effects of L‐NAME on blood pressure which suggests that tempol reduces bioavailability of nitric oxide on aortic isolated ring.
Evaluation of a Barrier Cream against the Chemical Warfare Agent VX using the Domestic White Pig
Authors: Chilcott Robert P. , Dalton Christopher H. , Hill Ira , Davison Corey M. , Blohm Kendal L. , Clarkson Edward D. , Hamilton Murray G.
Published: July 2005

Abstract: The purpose of this study was to evaluate the efficacy of a novel barrier cream formulation at reducing the percutaneous toxicity of a 2×LD50 liquid challenge of nerve agent (VX). The study was conducted in vitro and in vivo using the domestic pig. Pretreatment of the (inner ear skin) exposure site with barrier cream eliminated mortality, reduced cholinesterase inhibition and prevented any physiological or biochemical signs of intoxication. In contrast, untreated animals exposed to VX exhibited severe signs of intoxication, near total AChE inhibition and generally died within the (3 hr) exposure period (5/6 animals). Application of the barrier cream caused a significant decrease in the area of skin contaminated by VX. It was tentatively concluded that spreading was predominantly a surface phenomena (possibly mediated by capillary movement of the agent through the microrelief or between hair follicles) with little or no contribution from lateral diffusion within the stratum corneum. There was a disparity between the in vitro and in vivo skin absorption measurements that was ascribed to the absence of systemic clearance in vitro. However, both models indicated a substantial reservoir of VX within the skin, providing a potential strategy for future investigations into “catch‐up therapies”. In summary, the novel barrier cream formulation was effective against a 2×LD50 (liquid, percutaneous) dose of VX applied for 3 hr. Further work should be conducted to investigate more pragmatic issues such as optimal reapplication frequency and environmental effects such as temperature and humidity.
A Comparison of the Antinociceptive and Adverse Effects of the μ‐Opioid Agonist Morphine and the δ‐Opioid Agonist SNC80
Authors: Gallantine Elizabeth L. , Meert Theo F.
Published: July 2005

Abstract: δ‐Opioid receptor agonists have been postulated to induce analgesia without the adverse effects commonly associated with μ‐opioids e.g. morphine. In the present study, we evaluated the occurrence of antinociceptive and opioid‐like side effects in rats (n=5–7) treated with a single dose of subcutaneous morphine (0.01 to 40 mg/kg) or SNC80 (0.63 to 80 mg/kg). The antinociceptive effects of morphine and SNC80 were compared using a range of nociceptive tests including the tail withdrawal test, the acetic acid‐induced abdominal constriction (writhing) assay, the automated formalin test and a model of inflammation‐induced thermal hyperalgesia. The adverse effects of both drugs were examined in animal models for gastrointestinal (GI) inhibition (charcoal test; ricinus oil test), respiratory depression (blood‐gas analysis), motor disturbances (automated rotarod model) and abuse liability (drug discrimination learning).

Morphine displayed significant antinociceptive and adverse effects in all the animal models employed. SNC80 exhibited a significant effect in the writhing test and limited efficacy in a model of inflammation‐induced thermal hypersensitivity. A delay in the occurrence of diarrhoea and some limited increases in PCO2 were observed with the higher doses of SNC80 (≥40 mg/kg). In conclusion, the δ‐opioid agonist SNC80 lacks both the analgesic efficacy and adverse effects of μ‐opioids. However, the activity of SNC80 in the inflammatory model suggests δ‐opioid agonists may be useful analgesics in the treatment of some forms of inflammatory pain.
Turbine Blade Surface Deterioration by Erosion
Authors: Hamed Awatef A. , Tabakoff Widen , Rivir Richard B. , Das Kaushik , Arora Puneet
Published: July 2005

This paper presents the results of a combined experimental and computational research program to investigate turbine vane and blade material surface deterioration caused by solid particle impacts. Tests are conducted in the erosion wind tunnel for coated and uncoated blade materials at various impact conditions. Surface roughness measurements obtained prior and subsequent to the erosion tests are used to characterize the change in roughness caused by erosion. Numerical simulations for the three-dimensional flow field and particle trajectories through a low-pressure gas turbine are employed to determine the particle impact conditions with stator vanes and rotor blades using experimentally based particle restitution models. Experimental results are presented for the measured blade material/coating erosion and surface roughness. The measurements indicate that both erosion and surface roughness increase with impact angle and particle size. Computational results are presented for the particle trajectories through the first stage of a low-pressure turbine of a high bypass turbofan engine. The trajectories indicate that the particles impact the vane pressure surface and the aft part of the suction surface. The impacts reduce the particle momentum through the stator but increase it through the rotor. Vane and blade surface erosion patterns are predicted based on the computed trajectories and the experimentally measured blade coating erosion characteristics.
Combined Effects of Surface Trips and Unsteady Wakes on the Boundary Layer Development of an Ultra-High-Lift LP Turbine Blade
Authors: Zhang Xue Feng , Hodson Howard
Published: July 2005

An experimental investigation of the combined effects of upstream unsteady wakes and surface trips on the boundary layer development on an ultra-high-lift low-pressure turbine blade, known as T106C, is described. Due to the large adverse pressure gradient, the incoming wakes are not strong enough to periodically suppress the large separation bubble on the smooth suction surface of the T106C blade. Therefore, the profile loss is not reduced as much as might be possible. The first part of this paper concerns the parametric study of the effect of surface trips on the profile losses to optimize the surface trip parameters. The parametric study included the effects of size, type, and location of the surface trips under unsteady flow conditions. The surface trips were straight cylindrical wires, straight rectangular steps, wavy rectangular steps, or wavy cylindrical wires. The second part studies the boundary layer development on the suction surface of the T106C linear cascade blade with and without the recommended surface trips to investigate the loss reduction mechanism. It is found that the selected surface trip does not induce transition immediately, but hastens the transition process in the separated shear layer underneath the wakes and between them. In this way, the combined effects of the surface trip and unsteady wakes further reduce the profile losses. This passive flow control method can be used over a relatively wide range of Reynolds numbers.
Transition on Concave Surfaces
Authors: Dris Antonis , Johnson Mark W.
Published: July 2005

Boundary layer measurements have been made on the concave surfaces of two constant curvature blades using hot wire anemometry. All the current experiments were performed with negligible streamwise pressure gradient. Grids were used to produce a range of freestream turbulence levels between 1% and 4%. The freestream velocity increases with distance from a concave wall according to the free vortex condition making the determination of the boundary layer edge difficult. A flat plate equivalent boundary layer procedure was adopted, therefore, to overcome this problem. The Taylor–Goertler (TG) vortices resulting from the concave curvature were found to make the laminar and turbulent boundary layer profiles fuller and to increase the skin friction coeffiicent by up to 40% compared with flat plate values. This leads to a more rapid growth in boundary layer thickness. The evolution in the intermittency through transition is very similar to that for a flat plate, however, the shape factors are depressed slightly throughout the flow due to the fuller velocity profiles. For all the current experiments, curvature promoted transition. This was very marked at low freestream turbulence level but remained significant even at the highest levels. It appears that the velocity fluctuations associated with the TG vortices enhance the freestream turbulence resulting in a higher effective turbulence level. A new empirical correlation for start of transition based on this premise is presented. The ratio of end to start of transition momentum thickness Reynolds numbers was found to be approximately constant.
Discrete Green’s Function Measurements in Internal Flows
Authors: Booten Charles , Eaton John K.
Published: July 2005

The discrete Green’s function (DGF) for convective heat transfer was measured in a fully developed, turbulent pipe flow to test a new technique for simple heat transfer measurement. The 10×10 inverse DGF, G−1, was measured with an element length of approximately one pipe diameter and Reynolds numbers from 30,000 to 100,000 and compared to numerical predictions using a parabolic flow solver called STANTUBE. The advantages of using the DGF method over traditional heat transfer coefficients in predicting the thermal response for flows with nonuniform thermal boundary conditions are also demonstrated.
Additive Adsorption and Interfacial Characteristics of Nucleate Pool Boiling in Aqueous Surfactant Solutions
Authors: Zhang Juntao , Manglik Raj M.
Published: July 2005

Interfacial phenomena and ebullient dynamics in saturated nucleate pool boiling of aqueous solutions of three surfactants that have different molecular weight and ionic nature are experimentally investigated. The additive molecular mobility at interfaces manifests in a dynamic surface tension behavior (surfactant adsorption–desorption at the liquid–vapor interface), and varying surface wetting (contact angle) with concentration (surfactant physisorption at the solid–liquid interface). This tends to change, enhance, and control the boiling behavior significantly, and an optimum heat transfer enhancement is obtained in solutions at or near the critical micelle concentration (CMC) of the surfactant. Furthermore, wettability (contact angle) is observed to be a function of the molecular makeup of the reagent, and shows distinct regions of change along the adsorption isotherm that are associated with the aggregation mode of adsorbed ions at the solid–water interface. This distinguishably alters the ebullience from not only that in pure water, but also between pre- and post-CMC solutions. Increased wetting tends to suppress nucleation and bubble growth, thereby weakening the boiling process.
Effects of Backfill on Heat Transfer From a Buried Pipe
Authors: Ngo C. C. , Lai F. C.
Published: July 2005

Natural convection from a buried pipe with a layer of backfill is numerically examined in this study. The objective of the present study is to investigate how a step change in the permeability of the backfill would affect the flow patterns and heat transfer results. Numerical calculations have covered a wide range of the governing parameters (i.e., 10⩽Ra1⩽500 and 0.1⩽K1∕K2⩽10) for various backfill thicknesses (0.5⩽t∕ri⩽2). The results suggest that a more permeable backfill can minimize the heat loss and confine the flow to a region close to the pipe.
Capturing Sudden Increase in Heat Transfer on the Suction Side of a Turbine Blade Using a Navier–Stokes Solver
Authors: Rahman Faisal , Visser Jan A. , Morris Reuben M.
Published: July 2005

The numerical modeling of heat transfer on the suction side of a cooled gas turbine blade is one of the more difficult problems in engineering. The main reason is believed to be the transition from laminar to turbulent flow and the inability of standard Navier–Stokes solvers to predict the transition. This paper proves that sudden changes in heat transfer on the suction side of a turbine blade can indeed also be caused by localized shocks disrupting the boundary layer. In contrast to transition, the position of these shocks and the effect of the shocks on the pressure distribution and heat transfer rate can be predicted to within an acceptable degree of accuracy using standard Navier–Stokes solvers. Two well-documented case studies from the literature are used to prove that the pressure distribution around the profile can be predicted accurately when compared to experimental data. At the same time this method can be used to capture sudden changes in heat transfer rate caused by localized shocks. The conclusion from this study is that localized shock waves close to the suction side surface of a turbine blade can have the same effect on the heat transfer rate to the blade as transition.
Blade Aerodynamic Damping Variation With Rotor-Stator Gap: A Computational Study Using Single-Passage Approach
Authors: Li H. D , He L.
Published: July 2005

One of the outstanding issues in turbomachinery aeromechanic analysis is the intrarow interaction effects. The present work is aimed at a systematic examination of rotor-stator gap effects on blade aerodynamic damping by using a three-dimensional (3D) time-domain single-passage Navier-Stokes solver. The method is based on the upwind finite volume discretization and the single-passage shape-correction approach with enhanced accuracy and efficiency for unsteady transonic flows prediction. A significant speedup (by a factor of 20) over to a conventional whole annulus solution has been achieved. A parametric study with different rotor-stator gaps (56%–216% rotor tip chord) for a 3D transonic compressor stage illustrates that the reflection from an adjacent stator row can change rotor aerodynamic damping by up to 100% depending on the intrarow gap spacing. Furthermore, this rotor aerodamping dependency on the intrarow gap seems also to be affected by the number of stator blades. The predicted nonmonotonic relationship between the rotor blade aerodynamic damping and the gap spacing suggests the existence of an optimum gap regarding rotor flutter stability and/or forced response stress levels.
Adiabatic Effectiveness Measurements and Predictions of Leakage Flows Along a Blade Endwall
Authors: Ranson W. W. , Thole K. A. , Cunha F. J.
Published: July 2005

Traditional cooling schemes have been developed to cool turbine blades using high-pressure compressor air that bypasses the combustor. This high-pressure forces cooling air into the hot main gas path through seal slots. While parasitic leakages can provide a cooling benefit, they also represent aerodynamic losses. The results from the combined experimental and computational studies reported in this paper address the cooling benefit from leakage flows that occur along the platform of a first stage turbine blade. A scaled-up, blade geometry with an upstream slot, a mid-passage slot, and a downstream slot was tested in a linear cascade placed in a low-speed wind tunnel. Results show that the leakage flow through the mid-passage gap provides only a small cooling benefit to the platform. There is little to no benefit to the blade platform that results by increasing the coolant flow through the mid-passage gap. Unlike the mid-passage gap, leakage flow from the upstream slot provides good cooling to the platform surface, particularly in certain regions of the platform. Relatively good agreement was observed between the computational and experimental results, although computations overpredicted the cooling.
Inverse Design of and Experimental Measurements in a Double-Passage Transonic Turbine Cascade Model
Authors: Laskowski G. M. , Vicharelli A. , Medic G. , Elkins C. J. , Eaton J. K. , Durbin P. A.
Published: July 2005

A new transonic turbine cascade model that accurately produces infinite cascade flow conditions with minimal compressor requirements is presented. An inverse design procedure using the Favre-averaged Navier-Stokes equations and k‐ε turbulence model based on the method of steepest descent was applied to a geometry consisting of a single turbine blade in a passage. For a fixed blade geometry, the passage walls were designed such that the surface isentropic Mach number (SIMN) distribution on the blade in the passage matched the SIMN distribution on the blade in an infinite cascade, while maintaining attached flow along both passage walls. An experimental rig was built that produces realistic flow conditions, and also provides the extensive optical access needed to obtain detailed particle image velocimetry measurements around the blade. Excellent agreement was achieved between computational fluid dynamics (CFD) of the infinite cascade SIMN, CFD of the designed double passage SIMN, and the measured SIMN.
Computations of Flow Field and Heat Transfer in a Stator Vane Passage Using the v2¯−f Turbulence Model
Authors: Sveningsson A. , Davidson L.
Published: July 2005

In this study three-dimensional simulations of a stator vane passage flow have been performed using the v2¯−f turbulence model. Both an in-house code (CALC-BFC) and the commercial software FLUENT are used. The main objective is to investigate the v2¯−f model’s ability to predict the secondary fluid motion in the passage and its influence on the heat transfer to the end walls between two stator vanes. Results of two versions of the v2¯−f model are presented and compared to detailed mean flow field, turbulence, and heat transfer measurements. The performance of the v2¯−f model is also compared with other eddy-viscosity-based turbulence models, including a version of the v2¯−f model, available in FLUENT. The importance of preventing unphysical growth of turbulence kinetic energy in stator vane flows, here by use of the realizability constraint, is illustrated. It is also shown that the v2¯−f model predictions of the vane passage flow agree well with experiments and that, among the eddy-viscosity closures investigated, the v2¯−f model, in general, performs the best. Good agreement between the two different implementations of the v2¯−f model (CALC-BFC and FLUENT) was obtained.
Role of Thymic Output in Regulating CD8 T-Cell Homeostasis during Acute and Chronic Viral Infection
Authors: Miller Nicole E. , Bonczyk Jennifer R. , Nakayama Yumi , Suresh M.
Published: July 2005

Although it is well documented that CD8 T cells play a critical role in controlling chronic viral infections, the mechanisms underlying the regulation of CD8 T-cell responses are not well understood. Using the mouse model of an acute and chronic lymphocytic choriomeningitis virus (LCMV) infection, we have examined the relative importance of peripheral T cells and thymic emigrants in the elicitation and maintenance of CD8 T-cell responses. Virus-specific CD8 T-cell responses were compared between mice that were either sham thymectomized or thymectomized (Thx) at ∼6 weeks of age. In an acute LCMV infection, thymic deficiency did not affect either the primary expansion of CD8 T cells or the proliferative renewal and maintenance of virus-specific lymphoid and nonlymphoid memory CD8 T cells. Following a chronic LCMV infection, in Thx mice, although the initial expansion of CD8 T cells was normal, the contraction phase of the CD8 T-cell response was exaggerated, which led to a transient but striking CD8 T-cell deficit on day 30 postinfection. However, the virus-specific CD8 T-cell response in Thx mice rebounded quickly and was maintained at normal levels thereafter, which indicated that the peripheral T-cell repertoire is quite robust and capable of sustaining an effective CD8 T-cell response in the absence of thymic output during a chronic LCMV infection. Taken together, these findings should further our understanding of the regulation of CD8 T-cell homeostasis in acute and chronic viral infections and might have implications in the development of immunotherapy.
Vaccinia Virus A21 Virion Membrane Protein Is Required for Cell Entry and Fusion
Authors: Townsley Alan C. , Senkevich Tatiana G. , Moss Bernard
Published: July 2005

We provide the initial characterization of the product of the vaccinia virus A21L (VACWR140) gene and demonstrate that it is required for cell entry and low pH-triggered membrane fusion. The A21L open reading frame, which is conserved in all sequenced members of the poxvirus family, encodes a protein of 117 amino acids with an N-terminal hydrophobic domain and four invariant cysteines. Expression of the A21 protein occurred at late times of infection and was dependent on viral DNA replication. The A21 protein contained two intramolecular disulfide bonds, the formation of which required the vaccinia virus-encoded cytoplasmic redox pathway, and was localized on the surface of the lipoprotein membrane of intracellular mature virions. A conditional lethal mutant, in which A21L gene expression was regulated by isopropyl-β-
d
-thiogalactopyranoside, was constructed. In the absence of inducer, cell-to-cell spread of virus did not occur, despite the formation of morphologically normal intracellular virions and extracellular virions with actin tails. Purified virions lacking A21 were able to bind to cells, but cores did not penetrate into the cytoplasm and synthesize viral RNA. In addition, virions lacking A21 were unable to mediate low pH-triggered cell-cell fusion. The A21 protein, like the A28 and H2 proteins, is an essential component of the poxvirus entry/fusion apparatus for both intracellular and extracellular virus particles.
Suppression of RNA Interference by Adenovirus Virus-Associated RNA
Authors: Andersson M. Gunnar , Haasnoot P. C. Joost , Xu Ning , Berenjian Saideh , Berkhout Ben , Akusjärvi Göran
Published: July 2005

We show that human adenovirus inhibits RNA interference (RNAi) at late times of infection by suppressing the activity of two key enzyme systems involved, Dicer and RNA-induced silencing complex (RISC). To define the mechanisms by which adenovirus blocks RNAi, we used a panel of mutant adenoviruses defective in virus-associated (VA) RNA expression. The results show that the virus-associated RNAs, VA RNAI and VA RNAII, function as suppressors of RNAi by interfering with the activity of Dicer. The VA RNAs bind Dicer and function as competitive substrates squelching Dicer. Further, we show that VA RNAI and VA RNAII are processed by Dicer, both in vitro and during a lytic infection, and that the resulting short interfering RNAs (siRNAs) are incorporated into active RISC. Dicer cleaves the terminal stem of both VA RNAI and VA RNAII. However, whereas both strands of the VA RNAI-specific siRNA are incorporated into RISC, the 3′ strand of the VA RNAII-specific siRNA is selectively incorporated during a lytic infection. In summary, our work shows that adenovirus suppresses RNAi during a lytic infection and gives insight into the mechanisms of RNAi suppression by VA RNA.