The objective of this study was to determine if inflammatory tolerance and enhancement of innate immune function could be induced by the gram-positive cell wall component peptidoglycan (PGN)....Full Text Available
Protein isolated from hen egg-white and functions as a bacteriostatic enzyme by degrading bacterial cell walls. First enzyme ever characterized by protein ...
Abstract Toll-like receptor 2 (TLR2) is an immune sensor for gram-positive bacterial cell wall components. Single-nucleotide polymorphisms (SNPs) in the TLR2 gene that impair its function may, therefore, influence the risk and outcomes of gram-positive bacterial infections. In a cohort of 694 liver transplant recipients, we assessed the TLR2 SNP that is translated into an amino acid substitution of arginine for glutamine at position 753 (R753Q), and we found that its presence was associated with the clinical characteristics and outcomes of gram-positive bacterial infections. The proportions of patients with the TLR2 R753Q SNP did not significantly differ between those with gram-positive bacterial infections and those without gram-positive bacterial infections (9.6% versus 9.6%, P = 0.999)....
A nuclear fuel waste disposal vault would not likely be a sterile environment. Bacterial activity would be expected in those areas of the vault conducive to bacterial life, i.e., where effects of heat, moisture content, radiation and compaction would not prevent or severely restrict bacterial life and where suitable and sufficient nutrients would be present. An inventory of bacterial nutrients that would be emplaced 'intentionally' with vault materials (fuel waste, waste containers, buffer and backfill materials) has been made previously. This report assesses bacterial nutrients that would be added 'inadvertently' to a vault in the form of residues of materials used to excavate and operate a vault. Measurements of blasting material residues in the various water supplies, excavated broken rock (muck) and in cores drilled in old and new tunnel walls were made at ...
Clinical questionWhat is the best treatment for bacterial conjunctivitis?ResultsTopical antibiotics expedite recovery from bacterial conjunctivitis....Full Text Available
Objectives. The purposes of this study were to test the hypothesis that vaginal douching is linked to bacterial vaginosis in both symptomatic and asymptomatic women and to identify...Full Text Available
Chemoreceptors are crucial components in the bacterial sensory systems that mediate chemotaxis. Chemotactic responses exhibit exquisite sensitivity, extensive dynamic range and precise adaptation....Full Text Available
Bacterial cellulose was produced by Acetobacter xylinum (strain TISTR 975). Bacterial cellulose is an interesting material for using as a wound dressing since it provides moist environment to a wound resulting in a better wound healing. However, bacterial cellulose itself has no antimicrobial activity to prevent wound infection. To achieve antimicrobial activity, silver nanoparticles were impregnated into bacterial cellulose by immersing bacterial cellulose in silver nitrate solution. Sodium borohydride was then used to reduce the absorbed silver ion (Ag+) inside of bacterial cellulose to the metallic silver nanoparticles (Ag0). Silver nanoparticles displayed the optical absorption band around 420nm. The red-shift and broadening of the optical absorption band was observed when the mole rat...
Interkingdom signaling is established in the gastrointestinal tract in that human hormones trigger responses in bacteria; here, we show that the corollary is true, that a specific bacterial signal,...Full Text Available
Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI...Full Text Available
Genome-wide studies of bacterial gene expression are shifting from microarray technology to second generation sequencing platforms. RNA-seq has a number of advantages over hybridization-based techniques,...Full Text Available
Fatty acid biomarker analysis coupled with gas chromatography-isotope ratio mass spectrometry was used to confirm the presence of methanotrophic and thiotrophic bacterial endosymbionts in the tissues...Full Text Available
BackgroundThe study of bacterial species interactions in a mixed-species community can be facilitated by transcriptome analysis of one species in the community using cDNA microarray...Full Text Available
The results of antibiotic tests on bacterial pathogens freshly isolated from avian tissues and bovine milk are presented. Coliform isolates from the avian species showed an increased resistance to...Full Text Available
We have examined the association between cytokine, chemokine and growth factor concentrations with bacterial vaginosis (BV) in pregnant white and black women. A nested case-control analysis...Full Text Available
The introduction and survival of zoonotic bacterial pathogens in poultry farming have been linked to bacterial association with free-living protozoa. To date, however, no information is available on...Full Text Available
Severe pericardial effusion is a rare complication of bacterial pneumonia and it usually disappears under medical treatment. Herein we report a case of a girl with a congenital immunodeficient syndrome...Full Text Available
An explicit proposal for experiments leading to abrupt transitions in spatially extended bacterial populations in a Petri dish is presented on the basis of an exact formula obtained through an analytic...Full Text Available
Neonatal bacterial infection in rats alters the responses to a variety of subsequent challenges later in life. Here we explored the effects of neonatal bacterial infection on a subsequent drug...Full Text Available
Sibling Paenibacillus dendritiformis bacterial colonies grown on low-nutrient agar medium mutually inhibit growth through secretion of a lethal factor. Analysis of secretions reveals...Full Text Available
Infection due to multidrug resistance pathogens is difficult to manage due to bacterial virulence factors and because of a relatively limited choice of antimicrobial agents. Thus, it is imperative to...Full Text Available
The vaginal bacterial microbiota of 19 premenopausal women was examined by PCR-denaturing gradient gel electrophoresis (DGGE) and sequencing of the V2-V3 region of the 16S rRNA gene. Ten of the women...Full Text Available
Enteric infections with attaching/effacing lesion-inducing bacterial pathogens are a worldwide health problem. A murine infection model with one such pathogen, Citrobacter rodentium,...Full Text Available
The genetic systems of bacteria that have the ability to use organic pollutants as carbon and energy sources can be adapted to create bacterial biosensors for the detection of industrial pollution....Full Text Available
ObjectiveTo examine the role of first trimester bacterial vaginosis (BV) and level of BV-associated microorganisms diagnosed using the Nugent’s Gram stain...Full Text Available
Aim:The effect of Tualang honey on wound healing in bacterial contaminated full-thickness burn wounds was evaluated in 36 male Sprague Dawley rats.Materials...Full Text Available
In the Archaea only a handful of ribonucleases involved in RNA processing and degradation have been characterized. One potential group of archaeal ribonucleases are homologues of the bacterial RNase...Full Text Available
BackgroundBacterial vaginosis (BV) is a common condition that is associated with preterm birth and acquisition of complex communities of vaginal bacteria that include several fastidious...Full Text Available
BackgroundThe bacterial genus Listeria contains pathogenic and non-pathogenic species, including the pathogens L. monocytogenes and L. ivanovii,...Full Text Available
Bacterial pathogens use virulence strategies to invade epithelial barriers, but active processes of epithelial cells may also contribute to the endocytosis of microbial particles. To focus on the latter,...Full Text Available
The purpose of the work was to quantitatively characterize temperature effects on the bacterial leaching of sulfide ore material containing several sulfide minerals. The leaching was tested at eight...Full Text Available
We have used a sintered glass bead core to simulate the spaces and surfaces of reservoir rock in studies of the bacterial plugging phenomenon that affects waterflood oil recovery operations. The passage...Full Text Available
We examined the bacterial aerobic nasal flora of 216 healthy volunteers to identify potential competitive interactions among different species, with special emphasis on the influence of staphylococcal...Full Text Available
Gene expression from bacterial artificial chromosome (BAC) clones has been demonstrated to facilitate physiologically relevant levels compared to viral and nonviral cDNA vectors. BACs are large enough...Full Text Available
ObjectivesTo assess whether bacterial vaginosis or chlamydial infection before 10 weeks' gestation is associated with miscarriage before 16 weeks.DesignProspective...Full Text Available
Model systems to study the effects of chemicals of environmental concern on bacterial and parasitic diseases as well as the immunosurveillance and destruction of transplantable tumor cells were described...Full Text Available
To diagnose asymptomatic bacterial vaginosis (BV), self-sampled vaginal smears were collected during a study of risk factors for preterm birth in African American women. More than 90% of those...Full Text Available
Little is known about the conservation of determinants for the identities of tRNAs between organisms. We showed previously that Escherichia coli tyrosine tRNA synthetase can charge the Saccharomyces...Full Text Available
We show that the eigenvalue equations describing a cylindrical ideal magnetophydrodynamicsw (MHD) plasma interacting with a thin resistive wall can be put into the standard mathematical form: ??? = ??? ?. This is accomplished by using a finite element basis for the plasma, and by adding an extra degree of freedom corresponding to the electrical current in the thin wall. The standard form allows the use of linear eigenvalue solvers, without additional interations, to compute the complete spectrum of plasma modes in the presence of a surrounding restrictive wall at arbitrary separation. We show that our method recovers standard results in the limits of (1) an infinitely resistive wall (no wall), and (2) a zero resistance wall (ideal wall).
The real-time polymerase chain reaction (PCR) quantification of several vaginal bacterial groups in healthy women and patients developing asymptomatic bacterial vaginosis (BV) and candidiasis (CA) was performed. Statistical analysis revealed that the BV condition is characterised by a great variability among subjects and that it is associated with a significant increase of Prevotella, Atopobium, Veillonella and Gardnerella vaginalis, and a drop in Lactobacillus. On the contrary, the vaginal microflora of healthy women and patients developing CA was found to be homogeneous and stable over time. PMID:18762999
The real-time polymerase chain reaction (PCR) quantification of several vaginal bacterial groups in healthy women and patients developing asymptomatic bacterial vaginosis (BV) and candidiasis (CA) was performed. Statistical analysis revealed that the BV condition is characterised by a great variability among subjects and that it is associated with a significant increase of Prevotella, Atopobium, Veillonella and Gardnerella vaginalis, and a drop in Lactobacillus. On the contrary, the vaginal microflora of healthy women and patients developing CA was found to be homogeneous and stable over time.
The emergence of bacterial antibiotic resistance is a growing problem, yet the variables that influence the rate of emergence of resistance are not well understood. In a microfluidic device designed to mimic naturally occurring bacterial niches, resistance of Escherichia coli to the antibiotic ciprofloxacin developed within 10 hours. Resistance emerged with as few as 100 bacteria in the initial inoculation. Whole-genome sequencing of the resistant organisms revealed that four functional single-nucleotide polymorphisms attained fixation. Knowledge about the rapid emergence of antibiotic resistance in the heterogeneous conditions within the mammalian body may be helpful in understanding the emergence of drug resistance during cancer chemotherapy. PMID:21940899
Legionella pneumophila is a gram-negative bacterial species that is ubiquitous in almost any aqueous environment. It is the agent of Legionnaires’ disease, an acute and often...Full Text Available
BackgroundIt is well established that Legionella pneumophila is a waterborne pathogen; by contrast, the mode of Helicobacter pylori transmission...Full Text Available
Periodontitis is an infectious process characterized by inflammation affecting the supporting structures of the teeth. Porphyromonas gingivalis is a major oral bacterial species implicated...Full Text Available
Examining the relationship between biodiversity and functional stability (resistance and resilience) of activated sludge bacterial communities following disturbance is an important first step towards developing strategies for the design of robust biological wastewater treatment systems. This study investigates the relationship between functional resistance and biodiversity of dominant bacterial taxa by subjecting activated sludge samples, with different levels of biodiversity, to toxic shock loading with cupric sulfate (Cu[II]), 3,5-dichlorophenol (3,5-DCP), or 4-nitrophenol (4-NP). Respirometric batch experiments were performed to determine the functional resistance of activated sludge bacterial community to the three toxicants. Functional resistance was estimated as the 30?min IC50 or th...
... 84. Fields BS, Haupt T, Davis JP, Arduino MJ, Butler JC. Pontiac fever due to Legionella micdadei from a whirlpool spa: Possible role of bacterial endotoxin. ...
BackgroundThe metagenomic analysis of microbial communities holds the potential to improve our understanding of the role of microbes in clinical conditions. Recent, dramatic improvements...Full Text Available
The bacterium Serratia marcescens produces a plethora of multicellular shapes of different colorations on solid substrates, allowing immediate visual detection of varieties. Such a...Full Text Available
Background"Nubiotics" are synthetic oligonucleotides and nucleotides with nuclease-resistant backbones, and are fully protonated for enhanced ability to be taken up by bacterial...Full Text Available
Alpha-toxin, the major cytotoxic agent elaborated by Staphylococcus aureus, was the first bacterial exotoxin to be identified as a pore former. The protein is secreted as a single-chain, water-soluble...Full Text Available
Terminal differentiation of many vascular cells involves cell wall changes. Cells first elongate their primary wall, then lay down a lignified secondary wall, which is often followed by digestion of...Full Text Available
We study the production of gravitational waves from cosmic domain walls created during phase transition in the early universe. We investigate the process of formation and evolution of domain walls by running three dimensional lattice simulations. If we introduce an approximate discrete symmetry, walls become metastable and finally disappear. We calculate the spectrum of gravitational waves produced by collapsing metastable domain walls. Extrapolating the numerical results, we find the signal of gravitational waves produced by domain walls whose energy scale is around 10^10-10^12GeV will be observable in the next generation gravitational wave interferometers.
The molecular structure, chemical properties, and biological function of the xyloglucan polysaccharide isolated from cell walls of suspension-cultured sycamore (Acer pseudoplatanus)...Full Text Available
Bacterial plasmids contain specific genes for resistances to toxic heavy metal ions including Ag+, AsO2-, AsO4(3-), Cd2+, Co2+, CrO4(2-), Cu2+, Hg2+, Ni2+, Pb2+, Sb3+, and Zn2+. Recent progress with...Full Text Available
Caffeine and related xanthines were identified as potent stimulators for the bacterial cellulose production in A. xylinum. These compounds are present in several plants whose infusions are useful as culture-medium supplements for this acetobacterium. The proposed target for these native purine-like inhibitory substances is the novel diguanyl nucleotide phosphodiesterase(s) that participates in the bacterial cellulogenic complex.
β-Lactamases are the main cause of bacterial resistance to penicillins and cephalosporins. Class A β-lactamases, the largest group of β-lactamases, have been found in many bacterial...Full Text Available
Group B Streptococcus (GBS) is the leading cause of meningitis in newborn infants. Bacterial cell surface appendages, known as pili, have been recently described in streptococcal pathogens, including GBS. The pilus tip adhesin, PilA, contributes to GBS adherence to blood-brain barrier (BBB) endothelium; however, the host receptor and the contribution of PilA in central nervous system (CNS) disease pathogenesis are unknown. Here we show that PilA binds collagen, which promotes GBS interaction with the ?(2)?(1) integrin resulting in activation of host chemokine expression and neutrophil recruitment during infection. Mice infected with the PilA-deficient mutant exhibit delayed mortality, a decrease in neutrophil infiltration and bacterial CNS dissemination. We find that PilA-mediated virulence is dependent on neutrophil influx as neutrophil depletion results in a decrease in BBB permeability and GBS-BBB penetration. Our results suggest that the ...
Bacterial attachment-effacement (att-eff) is emerging as an important virulence characteristic common to both enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC). The contribution of the plasmid-encoded EPEC adherence factor to the production of mucosal lesions and diarrhea was investigated in gnotobiotic piglets. Bacterial att-aff in the intestinal mucosa of piglets infected with plasmid-cured EPEC strain E2348/69 (O127) was indistinguishable from that in piglets infected with the parent strain, but the distribution of lesions was different; it occurred in the small intestines of 6 of 7 piglets infected with the parent strain compared with only 2 of 11 (P = 0.006) infected with the plasmid-cured strain. Plasmid-encoded factors in EPEC and EHEC strains did not appear to contribute to bacterial competition with normal gut microflora. Of 13 strains belonging to five EPEC serogroups, O55, O142, O26, ...
In acute liver failure following hepatitis, toxic insults, or after major liver surgery, there is an increased bacterial translocation from the gut. This may explain some of the infectious complications seen in these conditions. To elucidate mechanisms and find possible preventive measures, we investigated the effect of rectal administration of arginine and probiotic bacteria (Lactobacillus spp.) on bacterial translocation and the extent of liver failure. Sprague-Dawley rats were used and five different Lactobacillus strains (Lb. reuteri R2LC, Lb. rhamnosus DSM 6594 (= strain 271), Lb. plantarum DSM 9843 (= strain 299v), Lb. fermentum 8704:3 (= strain 245), and Lb. reuteri (= strain 108) were administered rectally once daily for 8 days with and without 2% arginine. Acute liver injury (ALI) was induced on the eighth day by intraperitoneal injection of D-galactosamine (1.1 g/kg body weight), and samples were collected after 24 and 48 hours. ...
In a reactor environment, the surface of a limiter or wall is primarily determined by the mechanism of erosion and deposition of surface material. It should be possible to use pellet injection to reduce net erosion to zero everywhere if low-Z materials are used for the surface. Erosion rates can, in general, be minimized by large area limiters and high plasma temperatures, which transmit power to the walls with less sputtering. Under ideal steady state conditions the wall surface is dominated by metallurgical effects in the wall.
The paper investigates the effect of the wall heat flux ratio on the local heat transfer augmentation in a square channel with two opposite in-line ribbed walls for Reynolds numbers from 15,000 to 80,000. The square channel composed of 10 isolated copper sections has a length-to-hydraulic diameter ratio of 20. The rib height-to-hydraulic diameter ratio is 0.0625 and the rib pitch-to-height ratio equals 10. Six ribbed side to smooth side wall heat flux ratios are studied for four rib orientations. The results show that the ribbed side wall heat transfer augmentation increases with increasing ribbed side to smooth side wall heat flux ratios, but the reverse is true for the smooth side wall heat transfer augmentation. The average heat transfer augmentation of the ribbed side and smooth side wall decreases slightly with increasing ...
Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI medium indicated that transferrin was required for norepinephrine stimulation of growth of Escherichia coli. Since bacteriostasis by serum is primarily due to the iron-withholding capacity of transferrin, we considered the possibility that norepinephrine can overcome this effect by supplying transferrin-bound iron for growth. Incubation with concentrations of norepinephrine that stimulated bacterial growth in serum-SAPI medium resulted in loss of bound iron from iron-saturated transferrin, as indicated by the appearance of monoferric and apo- isoforms upon electrophoresis in denaturing gels. Norepinephrine also caused the loss of iron from lactoferrin. The pharmacologically inactive metabolite norepinephrine 3-O-sulfate, by contrast, did not result in ...
Radiological findings of chest and abdominal wall involvement in Hodgkin's disease are reported. This manifestation was diagnosed in one patient in the primary staging and in two patients during the course of the disease. Typical radiological findings are soft tissue masses in the chest and abdominal wall, in two cases with continous tumor growth of enlarged mediastinal lymphnodes into the anterior chest wall. The axial computed tomography is the best method to evaluate the extent of chest and abdominal wall involvement in Hodgkin's disease.
The growth power-time curves of a strain of petroleum bacteria, B-2, in various kinds of cultures containing different kinds of carbon sources, glucose, n-tetradecane, n-hexadecane and n-octadecane, and different kinds of microemulsions have been determined by using a 2277 Thermal Activity Monitor. The curves showed a single peak for cultures containing a single carbon source, glucose, and two peaks for cultures containing two kinds of carbon sources, glucose and one of the n-alkanes. The first peak indicated that bacteria grew by consuming glucose and the second peak indicated that bacteria grew by consuming n-alkane. The curves were complex when the bacterium grows in a microemulsion culture. According to a kinetic equation of bacterial growth under limited conditions, the rate constants of bacterial growth were obtained. The results showed that the microemulsion culture was more appropriate to bacteria to grow on n-alkanes.
This study investigates the turnover of polysaccharides by heterotrophic bacterioplankton in the northern Bay of Biscay, a productive marine system on the continental margin of the temperate Atlantic Ocean. Bacterial biomass production (BBP) near the surface ranged from 0.5 to 25.7 nmol C L?1 h?1 during small phytoplankton blooms in May and June that occurred after the main spring bloom. A direct relationship between BBP and total polysaccharides strongly suggests the dependence of bacterial growth on the availability of semi-labile organic matter. Concentrations of combined glucose as well as rate constants of extracellular glucosidase activity and glucose uptake were determined to estimate the actual carbon fluxes from bacterial polysaccharide turnover. Results reveal that ...
Preterm birth is a common cause of neonatal morbidity and mortality. Many asymptomatic genital infections have been associated with preterm birth, but attempts to determine a causal relationship between specific infections and preterm birth have been disappointing. Treatment trials of specific infections have generally failed to show a positive effect, and in some trials have shown a deleterious effect. Although there is a strong association between the presence of bacterial vaginosis and Trichomonas vaginalis in pregnancy and preterm birth, randomized treatment trials have failed to show a benefit of treatment of these organisms. Treatment of asymptomatic bacterial vaginosis or T. vaginalis to prevent preterm birth is not warranted. PMID:12112946
The colonization of an implant surface by bacteria is an extremely important medical problem, which often leads to the failure of medical devices. Modern surface modification techniques, such as ion implantation, can confer to the surfaces very different properties from those of the bulk underlying material. In this work, austenitic stainless steel 316 LVM has been superficially modified by Si^+ ion implantation. The effect of surface modification on the biocompatibility and bacterial adhesion to 316 LVM stainless steel has been investigated. To this aim, human mesenchymal stem cells (hMSCs), as precursor of osteoblastic cells, and bacterial strains relevant in infections related to orthopedic implants, i.e., Staphylococcus aureus and Staphylococcus epidermidis, have been assayed. For the ...
Coral populations have precipitously declined on Caribbean reefs while algal abundance has increased, leading to enhanced competitive damage to corals, which likely is mediated by the potent allelochemicals produced by both macroalgae and benthic cyanobacteria. Allelochemicals may affect the composition and abundance of coral-associated microorganisms that control host responses and adaptations to environmental change, including susceptibility to bacterial diseases. Here, we demonstrate that extracts of six Caribbean macroalgae and two benthic cyanobacteria have both inhibitory and stimulatory effects on bacterial taxa cultured from the surfaces of Caribbean corals, macroalgae, and corals exposed to macroalgal extracts. The growth of 54 bacterial isolates was monitored in the presence of l...
Here we use published 16S rRNA gene sequences to compare the bacterial assemblages associated with humans, other mammals, other metazoa, and free-living microbial communities spanning a range...Full Text Available
BackgroundDinoflagellates are unicellular, often photosynthetic protists that play a major role in the dynamics of the Earth's oceans and climate. Sequencing of dinoflagellate nuclear...Full Text Available
Peri-prosthetic infections are notoriously difficult to treat as the biomaterial implant is ideal for bacterial adhesion and biofilm formation, resulting in decreased antibiotic sensitivity....Full Text Available
BackgroundStreptococcus suis is an emerging zoonotic pathogen and is the leading cause of bacterial meningitis in adults in Vietnam. Systematic data on the antimicrobial...Full Text Available
Many bacterial pathogens produce extracellular proteases that degrade the extracellular matrix of the host and therefore are involved in disease pathogenesis. Dichelobacter nodosus...Full Text Available
Enzymes are versatile catalysts in laboratories and on an industrial scale; improving their immobilization would be beneficial to broadening their applicability and ensuring their (re)use. Lipid-coated...Full Text Available
A previous report of high levels of members of the domain Archaea in Antarctic coastal waters prompted us to investigate the ecology of Antarctic planktonic prokaryotes. rRNA hybridization...Full Text Available
Bacterial hydroxy fatty acids and alpha-hydroxy fatty acids have been demonstrated in complex lipid extracts of subgingival plaque and gingival tissue. However, little is known about the relationship...Full Text Available
The pathogenesis of Pseudomonas aeruginosa disseminated infections depends on bacterial interaction with blood vessels. We have hypothesized that in order to traverse the endothelial barrier, bacteria...Full Text Available
Several commonly occurring freshwater and marine plants and algae were screened for beta-D-galactosidase and beta-D-glucuronidase activities by using a 60-min enzyme assay based on the hydrolysis by...Full Text Available
Adaptive radiation is the rapid origination of multiple species from a single ancestor as the result of concurrent adaptation to disparate environments. This fundamental evolutionary process is considered...Full Text Available
In order to efficiently utilize natural cellulose materials to produce ethylene, three expression vectors containing the ethylene-forming enzyme (efe) gene from Pseudomonas...Full Text Available
Type 1 pilus directs bladder epithelial binding and invasion by uropathogenic Escherichia coli (UPEC) in the initial stage of cystitis, but the bacterial determinants of postinvasion...Full Text Available
Increased construction of residential canal communities along the southern coastline of the United States has led to a concern about their impact on water quality. Pollution of such dead-end canals...Full Text Available
Macrophage activation by the proinflammatory cytokine interferon-γ (IFN-γ) is a critical component of the host innate response to bacterial pathogenesis. However, the precise nature...Full Text Available
Bartonella species are being recognized as important bacterial human and canine pathogens, and are associated with multiple arthropod vectors. Bartonella DNA extracted...Full Text Available
Bacterial processes in soil, including biodegradation, require contact between bacteria and substrates. Knowledge of the three-dimensional spatial distribution of bacteria at the microscale is necessary...Full Text Available
A method of measuring the water potential of stored potato tubers (Solanum tuberosum L.) was needed to investigate the relationship of bacterial soft rot in tubers to water potential....Full Text Available
... were erroneous. The oriental rat flea, Xenopsylla cheopis Rothschild, is considered to be the primary vector of ... laboratory and production of Weigl's exanthematous typhus vaccine. In Maintenance of hum...
BackgroundThe maternally inherited, bacterial symbiont, parthenogenesis inducing (PI) Wolbachia, causes females in some haplodiploid insects to produce daughters...Full Text Available
The gram-negative plant-pathogenic bacterium Xanthomonas campestris pv. vesicatoria is the causative agent of bacterial spot disease in pepper and tomato plants, which leads to economically...Full Text Available
Previous experimental data from various laboratories indicate that endotoxin of gram-negative oral microorganisms might be one of the most important bacterial products involved in bone resorption during...Full Text Available
To define the import pathway for apoiso-1-cytochrome c in vivo, the coding region for bacterial chloramphenicol acetyltransferase (CAT) or yeast copper metallothionein (CuMT) was fused to the carboxy...Full Text Available
The plasmid pE194 (3.7 kilobases) is capable of integrating into the genome of the bacterial host Bacillus subtilis in the absence of the major homology-dependent RecE recombination system. Multiple...Full Text Available
The electrokinetic patterns of four bacterial species (Bacillus subtilis, Bacillus megaterium, Pseudomonas aeruginosa, and Agrobacterium radiobacter), two yeasts (Saccharomyces cerevisiae and Candida...Full Text Available
Clindamycin concentrations in gingival crevicular fluid and in blood were determined over a 7-h period and were related to the minimal inhibitory concentrations of this agent for 340 bacterial strains...Full Text Available
The continued evolution of bacterial pathogens has major implications for both human and animal disease, but the exchange of genetic material between host-restricted pathogens is rarely considered....Full Text Available
Zinc is an essential trace metal ion for growth, but an excess of Zn is toxic and microorganisms express diverse resistance mechanisms. To understand global bacterial responses to excess Zn, we conducted...Full Text Available
Purpose of reviewSevere congenital neutropenia (SCN) is a primary immunodeficiency in which lack of neutrophils causes inadequate innate immune host response to bacterial...Full Text Available
BackgroundBerberine is a plant alkaloid that is widely used as an anti-infective in traditional medicine. Escherichia coli exposed to berberine form filaments, suggesting...Full Text Available
On agar plates, daughter cells of Escherichia coli mutually slide and align side-by-side in parallel during the first round of binary fission. This phenomenon has been previously attributed...Full Text Available
Clostridium perfringens type A food poisoning is the second most commonly identified bacterial food-borne illness. Sporulation contributes to this disease in two ways: (i) most food-poisoning...Full Text Available
This study examines the results of bacterial culture from 159 endometrial biopsy samples from 97 commercial dairy cows and correlations between bacteriological and histological findings. Bacteria were...Full Text Available
Bacterial nitric oxide synthases (bNOS) are present in many Gram-positive species and have been demonstrated to synthesize NO from arginine in vitro and in vivo. However, the physiological role...Full Text Available
We investigated the effects of wastewater treatment plant (WWTP) discharge on the ecology of bacterial communities in the sediment of a small, low-gradient stream in South Australia. The quantification...Full Text Available
Rumen-cannulated cows (n = 4) were fed successively silage made from either conventional or genetically modified (GM) maize. Results revealed no effects of GM maize on the dynamics...Full Text Available
Cutaneous leishmaniasis (CL) is a parasitic disease characterized by single or multiple ulcerations. Secondary bacterial infections are one of the complications that can increase the tissue destruction...Full Text Available
Many pathogens colonize different anatomical sites, but the selective pressures contributing to survival in the diverse niches are poorly understood. Group A Streptococcus (GAS) is...Full Text Available
The display of proteins such as feed enzymes at the surface of bacterial spore systems has a great potential use for animal feed. Feed enzymes increase the digestibility of nutrients, leading to greater...Full Text Available
Caries is a multifactorial disease, and studies aiming to unravel the factors modulating its etiology must consider all known predisposing factors. One major factor is bacterial colonization,...Full Text Available
We sequenced 16S rRNA genes from the vaginal swab contents of a postmenopausal woman with asymptomatic bacterial vaginosis (BV). Sequences from Atopobium vaginae were the most commonly...Full Text Available
In order to identify novel high value antibacterial targets it is desirable to delineate whether the inactivation of the target enzyme will lead to bacterial death or stasis. This knowledge is particularly...Full Text Available
Several independent studies of bacterial degradation of nitrate ester explosives have demonstrated the involvement of flavin-dependent oxidoreductases related to the old yellow enzyme (OYE) of yeast....Full Text Available
Biodegradation/solubilization of coal is described. The degradation of dibenzothiophene by two bacterial strains is reported. The effects of adding salicylate to the treatments was also investigated. 2 figs., 5 tabs. (CBS)
Certain pathogenic species of Bacillus and Clostridium have developed unique methods for intoxicating cells that employ the classic enzymatic “A-B” paradigm for protein toxins. The binary...Full Text Available
BackgroundOceans are iron-deficient and nutrient-poor environments. These conditions impart limitations on our understanding of and our ability to identify microorganisms from the...Full Text Available
Escherichia coli infection of the endometrium causes uterine disease after parturition and is associated with prolonged luteal phases of the ovarian cycle in cattle. Termination...Full Text Available
In Iran, microscopic examination of skin scrapings from 2202 individuals with clinically diagnosed cutaneous leishmaniasis (CL) lesions revealed the presence of amastigotes in 1123 cases (51.0%). Bacteriological...Full Text Available
Inadequate measures of water quality have been used in many studies of the health effects associated with water supplies in developing countries. The present 1-year epidemiological-microbiological study...Full Text Available
The CD1 family of proteins binds self and foreign glycolipids for presentation to CD1-restricted T cells. To identify previously uncharacterized active CD1 ligands, especially those of microbial origin,...Full Text Available
Acute Otitis Media occurs mostly after upper respiratory tract infection; the causative bacteria are those colonized in the nasopharynx. We studied 709 URI episodes and found that children with...Full Text Available
BackgroundSepsis or bacteraemia, however rare, is a significant cause of high mortality and serious complications in children. In previous studies skin disease or skin infections...Full Text Available
A total of 193 bacterial strains were tested for their susceptibilities to 14 antimicrobial agents. Penicillin G was active at 2 U/ml against 98% of the oral isolates. Other antibiotics with good activity...Full Text Available
The distribution and activity of communities of sulfate-reducing bacteria (SRB) and methanogenic archaea in two contrasting Antarctic sediments were investigated. Methanogenesis dominated in freshwater...Full Text Available
The mechanism by which enzyme IIIglc of the bacterial phosphotransferase system regulates the activity of crystalline glycerol kinase from Escherichia coli has been studied, and the inhibitory effects...Full Text Available
BackgroundThe successful interaction of bacterial pathogens with host tissues requires the sensing of specific chemical and physical cues. The human gut contains a huge number of...Full Text Available
BackgroundBacterial constituents, such as Gram-negative derived lipopolysaccharide (LPS), can initiate inflammatory bone loss through induction of host-derived inflammatory...Full Text Available
Saccharococcus sacchari is the primary colonizer of the developing “sterile” tissue between the leaf sheath and stem of sugar cane. The honeydew secreted by the mealybugs...Full Text Available
The accumulation of α-1,4-polyglucans is an important strategy to cope with transient starvation conditions in the environment. In bacteria and plants, the synthesis of glycogen and starch occurs...Full Text Available
OBJECTIVE: The efficacy of Toto ointment and soap on common skin disorders was tested. METHODOLOGY: A cohort of Nigerians with common skin conditions such as fungal and bacterial skin infections, scabies,...Full Text Available
Bacterial artificial chromosome (BAC) clones are effective mapping and sequencing reagents for use with a wide variety of small and large genomes. This report describes the development of a physical...Full Text Available
A DNA fragment located on the 3' side of the Coxiella burnetii htpAB operon was determined by Southern blotting to exist in approximately 19 copies in the Nine Mile I genome. The DNA sequences of this...Full Text Available
Wall thickness measurement of pipe is very important of the structural integrity of the industrial plant. However, the radiography method has an advantage because the ability of penetrating the insulated pipe. This will have economic benefit for industry. Moreover, the era of digital radiography has more advantages because the speed of radiographic work, less exposure time and no chemical used for film development. Either the conventional radiography or digital radiology, the wall thickness measurement is using the tangential radiography technique (TRT). In case, of a large diameter, pipe (more than inches) the determination maximum penetration wall thickness must be taken into the consideration. This paper is revisited the mathematical derivation of the determination of wall thickness measurement based on tangential radiography technique (TRT). The mathematical approach used in this derivation is the ...
A review of tests on earthquake-resistant reinforced concrete structural walls is presented. Laboratory tests of isolated walls and construction joints are discussed. Where appropriate, design recommendations are given. The review indicates only few experimental data are available for short walls which are directly applicable to nuclear power plant design. In particular, tests of short rectangular walls subjected to load reversals are needed. Tests are also needed to determine the damping and frequency characteristics of cracked short walls. Analytical and experimental results should be correlated so that the hysteretic response observed in tests can be realistically related to the analytical response 'demand' of nuclear power plant structures. (Auth.).
This paper summarizes the findings from an exploratory definition of a usage strategy for multiple control centre wall displays in CANDU nuclear power plants. Wall displays are defined as large sized, vertically oriented display surfaces that may be positioned in various locations about a control room to support user information needs. The paper begins by discussing the need for a usage strategy for all control room information resources, and then reviews the history in wall display implementation and usage in nuclear power plant control rooms. The balance of the paper discusses the approach used in characterization and review of control room task information needs and definition of a wall display usage strategy. The paper concludes by outlining some of the possible impacts on future control room design and operations that the introduction of wall displays may imply. (author)
The transfer of fish from field to laboratory facilities or their propagation in closed or restricted systems frequently results in bacterial infection and ultimately large-scale mortality. In attemps to alleviate this problem, we have added tetracycline hydrochloride to the water prophylactically (pretreating tanks before wild fish were added) and therapeutically (treating tanks after bacterial outbreaks were detected.) In the present study, we examined the effect of tetracyline hydrochloride on the critical thermal maximum (CTM) of the common shiner (Notropis cornutus).
Walled-off pancreatic necrosis (WOPN), formerly known as pancreatic abscess is a late complication of acute pancreatitis. It can be lethal, even though it is rare. This critical review provides an overview...Full Text Available
The dwelling is equipped with solar collectors which heat the air circulating in the cavity walls and the space beneath the floors. The thermal aspects of such a building are described. Heat balance, losses, heating by the sun in different seasons are described. Different measures taken to reduce the energy losses are described.
The fungal pathogen Candida albicans is one of the leading causative agents of death in immunocompromised individuals. It harbors an arsenal of cell wall anchored factors that are implicated...Full Text Available
This report describes a field-test program to determine the effectiveness of a polymeric wall sealant to reduce the escape of naturally occurring radioactive gas radon from the walls of an underground uranium mine into the ventilation air.
Poland's anomaly is an uncommon congenital aberration of the chest wall characterized by absence of the pectoralis major muscle and other nearby musculoskeletal components. In this series, a wide spectrum...Full Text Available
A technique is described for displaying distinct tissue layers of large blood vessel walls as well as measuring their mechanical strain. The technique is based on deuterium double-quantum-filtered (DQF)...Full Text Available
Blunt chest-wall trauma is common; however, resultant tricuspid valve rupture is rare and can be subtle in its presentation. Transthoracic echocardiography plays a key role in diagnosis.Herein,...Full Text Available
BackgroundClinical studies suggest that local wall shear stress (WSS) patterns modulate the site and the progression of atherosclerotic lesions. Computational fluid dynamics (CFD)...Full Text Available
Ewing's sarcoma is the second most common malignant bone tumor in children and young adults. It is most prevalent between the ages of 10 and 15 years. There are present two cases of Ewing's sarcoma of the chest wall. The clinical, radiological and pathological features are described and the therapeutic options are discussed. (Author)
Primary cell walls, free from cytoplasmic contamination were prepared from corn (Zea mays L.) roots and potato (Solanum tuberosum) tubers. After EDTA treatment, the...Full Text Available
BackgroundDuring normal breathing, the mesothelial surfaces of the lung and chest wall slide relative to one another. Experimentally, the shear stresses induced by...Full Text Available
Purified cell walls were prepared from roots of Horse bean (Vicia faba L., var. minor) and Yellow Lupine (Lupinus luteus L.). Two methods were used:...Full Text Available
A general model for wakefield-generated instabilities in linear accelerators, originally developed for cumulative beam breakup [1], is applied to the resistive wall instability. The general solution for various bunch charge distributions and application to various accelerator configurations are presented.
... Although other authors had made cross-spectral density measurements, Corcos pointed to the importance of this function as indicative of the true ...
A theoretical analysis of two-dimensional unsteady flow in a porous medium bounded by a horizontal wall is presented as a perturbation on a basic flow. It is assumed that the perturbation is occasioned by a sudden suction at the wall. Even for a highly permeable medium the characteristic Reynolds number in porous media flow is usually small and asymptotic solutions are developed by the Laplace transform technique. It is observed that the perturbed shear stress at the wall decays exponentially with time. (author). 5 refs.
Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.
Naturally occurring radioactive materials (NORM) in seven new type wall materials were surveyed. The radioactivity was determined with HPGe-#gamma# spectrometer. The red mud has the highest radioactivity concentration, followed by slag building blocks, fly-ash building blocks (bricks), gangue bricks and light weight board materials, gypsum blocks. Fly-ash and slag contain higher NORM, which contributes the major part of the radioactivity in new wall materials. (authors)
A quantitative description is proposed for the depletion-induced slip thickness and velocity profile of a polymer solution near the wall-fluid interface in simple shear flow. The inhomogeneous polymer density profile at a flat wall is inserted into the equations of motion for the flow of a polymer solution near the flat wall. The theory is in quantitative agreement with simulation results. (letter to the editor)
As a part of a phenomenological model, a method for simulating the wall/jet interaction in a direct injection diesel engine is proposed. The method is based on the application of the momentum conservation equation in the different directions in which the wall jet is spread, and takes into account both the interaction with the combustion chamber geometry and with swirl. It takes as initial conditions the results of calculating the free jet, which is divided into packages. The predictions provide good agreement with those by other researchers. (author).
The purpose of the invention is to simplify assembly and to reduce labor intensity. This is achieved by the fact that the assembly shaft is positioned in a hawser, while its wall which is turned towards the body of the installation is combined with the hawser wall, where a U shaped opening is made in the wall of the assembly shaft, along the edges of which there is a hermetically sealing device, while the bottom of the body of the offshore drilling rig is equipped with a rigid insert attached with the capability of adjoining it with the hermetically sealing device.
This paper describes a new time-resolved three-dimensional, three-component (3D-3C) measurement technique called wall-PIV. It was developed to assess near wall flow fields and shear rates near non-planar surfaces. The method is based on light absorption according to Beer-Lambert's law. The fluid containing a molecular dye and seeded with buoyant particles is illuminated by a monochromatic, diffuse light. Due to the dye, the depth of view is limited to the near wall layer. The three-dimensional particle positions can be reconstructed by the intensities of the particle's projection on an image sensor. The flow estimation is performed by a new algorithm, based on learned particle trajectories. Possible sources of measurement errors related to the wall-PIV technique are analyzed. The accuracy analysis was based on single particle experiments and a three-dimensional artificial data set ...
The experimental survey about the heat transfer between the working fluid and the combustion chamber wall with a direct injection diesel engine has shown the production of a soot layer with increasing loads on the combustion chamber wall. Because the combustion process of methanol occurs without the formation of wall deposits, the same engine spark ignitioned with methanol at the same conditions has shown a higher heat transfer coefficient. Because the heat losses do not only depend on the heat transfer coefficient but also on the driving temperature difference between the working fluid and the combustion chamber wall, the methanol engine with corresponding process management showed lower heat losses than the diesel engine at nearly the same load. (orig./HW)
With the combination of source ventilation and ceiling cooling for air-conditioning of working and recreation rooms, a ventilation system is available which fulfills the highest demands regarding thermal comfort. In order to utilize the advantages of this ventilation system with regard to air quality and thermal comfort to an optimum, the influence of the radiation exchange between cooling ceiling and walls on the flow in the room is investigated experimentally. Energy transfer from the walls to the cooled ceiling may result in an insufficient temperature of the walls compared to ambient air and in an upward flow on the wall surfaces (downward flow of) driven by gravity, which influences the flow pattern in the case of source ventilation. (orig.)
Improved separation of heavier material from a dispersoid of gas and heavier material entrained therein is taught by the method of this invention which advantageously uses apparatus embodied in an inertial separator having rotary partition means comprising wall members dividing a housing into a plurality of axially-extending through passages arranged in parallel. Simultaneously with the helical transit of a moving stream of the dispersoid through the parallel arrangement of axially-extending through passages at a constant angular velocity, the heavier material is driven radially to the collecting surfaces of the rotational wall members where it is collected while the wall members are rotating at the same angular velocity as the moving stream. The plurality of wall members not only provides an increased area of collecting surfaces but the positioning of each of the wall members ...
Following Hurricane Katrina, the study of cantilevered sheet pile I-wall with gap or partial gap has become one of the central elements of the ongoing investigation pertaining to the re-building of hurricane protection systems in New Orleans, LA. Historically, the US Army Corps of Engineers (USACE) had mostly relied upon the Method of Planes (MOP) analysis procedure for slope stability analysis of I-wall systems. However MOP is a simplified procedure which does not satisfy total equilibrium. Nevertheless, MOP is still considered by USACE as a popular analysis tool because of its simplicity and ease of use in slope stability analysis. This paper demonstrates the applicability and suitability of MOP as a viable analysis tool for the analysis of New Orleans I-wall founded on layered cohesive ...
Expression of Bacterial luciferase enzyme (lux) in mammalian cells would be a powerful bioreporter protein system for in vivo imaging because eukaryotic luciferases need expensive substrates. However, only a few efforts have been made to express bacterial luciferase enzyme in mammalian cells. As the result of this, we attempted to construct bicistronic vector including two bacterial luciferase genes (LuxA and LuxB) for assessing the potential to be visualized in vitro or in vivo by optical imaging system after transfection to mammalian cells. We designed and synthesized luxA and luxB genes from Photorhabdus Luminescens. To co-express both luxA and luxB genes from a single promoter, we cloned as a bicistronic transcript fused with an internal ribosomal entry site (IRES). This bicistronic transcript was transfected by Superfect to HEK 293T cell line. We also transfected lux A and lux B vector to HEK 293T cells separately. To ...
The unsteady state heat transfer behaviour of a vertical wall subject to the effects of uniform radiation is investigated and the dimensional analysis of combined heat transfers by conduction, convection and radiation is presented. The convective heat transfer coefficients used in the numerical model are determined experimentally by means of an assembly resembling the conditions encountered in the dwelling (variable temperatures and heat flows in time and space, wall associated with a floor, radiative flux outside the wall). In routine conditions (homogeneous wall dimensions, temperature differentials less than 40/sup 0/C), it is shown that the problem depends in practice on three parameters (instead of five) and that nomographs can give the energy accumulated in the wall as a function of its geometric and thermal charactersitics and the external conditions (type and thickness of ...
From the results of the In-Service Inspection (ISI) measuring the wall thickness of outlet (hot-leg side) feeder pipes performed at two Canadian nuclear power plants, Point Lepreau and Gentilly-2 in 1995 and 1996, respectively, the wall thinning degradation of feeder pipes at the bend part was found to be much more severe than expected. It has been well known that such wall thinning of feeder pipes is caused by the flow accelerated corrosion (FAC) which is one of the mechanical-chemical degradation mechanisms affecting the integrity of piping systems. For the Wolsung unit 1, the wall thickness measurements have been performed during every overhaul period since 1996. The wall thinning rates at the bends of outlet feeder pipes were assessed to exceed the design value. However, for the Wolsung units 2, 3 and 4, the wall thinning rates of all the outlet feeder pipes ...
From the results of the In-Service Inspection (ISI) measuring the wall thickness of outlet (hot-leg side) feeder pipes performed at two Canadian nuclear power plants, Point Lepreau and Gentilly-2 in 1995 and 1996, respectively, the wall thinning degradation of feeder pipes at the bend part was found to be much more severe than expected. It has been well known that such wall thinning of feeder pipes is caused by the flow accelerated corrosion (FAC) which is one of the mechanical-chemical degradation mechanisms affecting the integrity of piping systems. For the Wolsung unit 1, the wall thickness measurements have been performed during every overhaul period since 1996. The wall thinning rates at the bends of outlet feeder pipes were assessed to exceed the design value. However, for the Wolsung units 2, 3 and 4, the wall thinning rates of all the outlet feeder pipes ...
Cultures of 3T3-L1 cells were incubated with either 10 ng/ml cholera toxin or 10 ng/ml pertussis toxin from 4 days prior to the initiation of differentiation and throughout the subsequent incubation. Toxin concentrations were sufficient to completely prevent the labelling of alpha-subunits with ["3"2P]NAD"+ and pertussis toxin and to prevent by more than 90% the labelling with ["3"2P]NAD"+ and cholera toxin in membranes prepared from these cells. Neither toxin prevented the differentiation to the adipocyte phenotype. Neither toxin prevented the increases in the relative amounts of G-proteins which occur upon differentiation. Both toxins dramatically decreased the amount of beta-subunits. As measured by quantitative immunoblotting with antisera specific for both the 35 kDa and 36 kDa beta-subunits, levels of beta-subunit were decreased by more than 50% of steady-state level of control cells. Thus, bacterial toxins which modifies G-protein alpha-subunits are capable ...
The two-compartment radioassay for microbial kinetics based on continuous measurement of the {sup 14}CO{sub 2} released by bacterial metabolism of 14C-labeled substrate offers a valuable approach to testing the potency of antimicrobial drugs. By using a previously validated radioassay with gram-positive and gram-negative bacteria, a group of protein synthesis inhibitors was evaluated for their effect on microbial growth kinetics. All tested drugs induced changes in both the slopes and intercepts of the growth curves. An exponential growth model was applied to quantify the drug effect on the processes of bacterial {sup 14}CO{sub 2} liberation and cell generation. The response was measured in terms of a generation rate constant. A linear dependence of the generation rate constant on the dose of spectinomycin was observed with Escherichia coli. Sigmoidal-shaped curves were found in the assays of chloramphenicol and tetracycline. The implications ...
In 18 piglets, weighing 10-15 kg, third-degree burns or full-thickness skin excisions of 4 X 4 cm were inflicted. The effect of five dressing materials on adhesiveness to the wounds, appearance, conformability, wound contraction, bacterial count, and morphology of the wound was studied at the end of the seventh and fourteenth days without dressing changes. In 11 piglets with a burn wound, the most adherent dressing was collagen sponge(CS), followed by polyurethane sponge (PU), pigskin xenograph (PS), and xeroform. CS more effectively debrided the wound from coagulated necrotic tissue than the other dressings. Wound contraction was maximal with CS dressing (52%), followed by PU (44%), xeroform (32%), and PS (27%). In another seven piglets with full-thickness excised wounds, a velour dressing made of polytetrafluoroethylene (PTFE) or PU adhered significantly more than CS or PS. Wound contraction was greater with CS (37%) or PTFE (35%) than with PS (23%) or PU (18%). ...
A comprehensive and highly selective method for detecting in bacterial supernatants a modified sulfur nucleoside, S-adenosyl-L-methionine (SAM), and its metabolites, i.e., S-adenosylhomocysteine (SAH), adenosine (Ado), 5prime-deoxy-5prime-methylthioadenosine (MTA), adenine (Ade), S-adenosyl-methioninamine (dcSAM), homocysteine (Hcy) and methionine (Met), was developed. The method is based on reversed-phase liquid chromatography with positive electrospray ionization (ESI+) coupled to a hybrid linear quadrupole ion trap (LTQ) and 7-T Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). A gradient elution was employed with a binary solvent of 0.05 M ammonium formate at pH 4 and acetonitrile. The assay involves a simultaneous cleanup of cell-free bacterial broths by solid-pha...
A dialyzable factor(s) in human serum is known to stimulate gonococcal oxygen consumption. Its effect on other human pathogens was investigated. A 10% serum solution increased peak O2 consumption for Escherichia coli and Staphylococcus aureus to 157% (P less than 0.05) and 199% (P less than 0.02), respectively, of their O2 consumption when suspended in Hanks balanced salt solution, compared with a 356% increase for Neisseria gonorrhoeae with serum. Dialyzed serum lacked stimulatory capacity. Bacteria, serum, and neutrophils are often incubated to evaluate neutrophil bactericidal activity. Samples of 10(8) N. gonorrhoeae, S. aureus, and E. coli turned resazurin colorless (anaerobic conditions, Eh less than -42 mV) after 7.4, 13.3, and 15.1 min, respectively. Because neutrophil formation of reactive oxygen intermediates requires ambient O2, the effect of live bacteria and serum on this process was explored. After 5 min of incubation of 10(8) N. gonorrhoeae or S. aureus in 10% normal or ...
Objective To compare matrix metalloproteinase (MMP)-8 and MMP-9 levels in the vaginal secretions of pregnant women with or without asymptomatic bacterial vaginosis (BV). Methods In this study, vaginal levels and molecular forms of MMP-8 and MMP-9 were studied in 36 pregnant women between 28 and 34 weeks of gestation with asymptomatic BV and 41 pregnant women, matched for gestational age, without BV. Results Vaginal MMP-8 concentrations were significantly higher (P = .023) in BV-positive women. There was no significant difference in MMP-9 levels between healthy pregnant controls and BV-positive pregnant women. The presence of MMP-8 was confirmed by a 38-kd band on Western blots. Conclusions Our findings show that BV is associated with increased levels of MMP-8 in vaginal fluid. Increased pr...
We revisit a recently proposed agent-based model of active biological motion and compare its predictions with own experimental findings for the speed distribution of bacterial cells, Salmonella typhimurium. Agents move according to a stochastic dynamics and use energy stored in an internal depot for metabolism and active motion. We discuss different assumptions of how the conversion from internal to kinetic energy d(v) may depend on the actual speed, to conclude that d 2 v ? with either ? = 2 or 1 ? < 2 are promising hypotheses. To test these, we compare the model?s prediction with the speed distribution of bacteria which were obtained in media of different nutrient concentration and at different times. We find that both hypotheses are in line with the experimental observations, with ? bet...
Eugenol, the principal chemical component of clove oil from Eugenia aromatica has been long known for its analgesic, local anesthetic, anti-inflammatory, and antibacterial effects. The interaction of the eugenol with ten different hydrophobic and hydrophilic antibiotics was studied against five different Gram negative bacteria. The MIC of the combination was found to decrease by a factor of 5-1000 with respect to their individual MIC. This synergy is because of the membrane damaging nature of eugenol, where 1mM of its concentration is able to damage nearly 50% of the bacterial membrane. Eugenol was also able to enhance the activities of lysozyme, Triton X-100 and SDS in damaging the bacterial cell membrane. The hydrophilic antibiotics such as vancomycin and b-lactam antibiotics which have ...
Individuals with sickle cell disease (SCD) demonstrate an increased susceptibility to invasive bacterial infections (IBI). The most common organisms causing IBI are Streptococcus pneumoniae, nontyphi Salmonella species and Haemophilus influenzae type b (Hib). IBI are the most common causes of death in children below 5 years of age with SCD. Increased susceptibility to IBI is because of several factors including dysfunctional antibody production and opsonophagocytosis as well as defective splenic clearance. Early diagnosis of Hib and pneumococcal infections combined with antibiotic prophylaxis and immunization programs, could lead to significant improvements in mortality, especially in Africa. Pediatr Blood Cancer. 2010;55:401-406. Copyright 2010 Wiley-Liss, Inc.
Abstract Plant pathogenic bacteria of the genus Xanthomonas cause a variety of diseases in economically important monocotyledonous and dicotyledonous crop plants worldwide. Successful infection and bacterial multiplication in the host tissue often depend on the virulence factors secreted including adhesins, polysaccharides, LPS and degradative enzymes. One of the key pathogenicity factors is the type III secretion system, which injects effector proteins into the host cell cytosol to manipulate plant cellular processes such as basal defense to the benefit of the pathogen. The coordinated expression of bacterial virulence factors is orchestrated by quorum-sensing pathways, multiple two-component systems and transcriptional regulators such as Clp, Zur, FhrR, HrpX and HpaR. Furthermore, virule...
For the purpose of nationwide surveillance of the antimicrobial susceptibility of bacterial respiratory pathogens collected from patients in Japan, the Japanese Society of Chemotherapy conducted a third year of nationwide surveillance during the period from January to April 2008. A total of 1,097 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 987 strains (189 Staphylococcus aureus, 211 Streptococcus pneumoniae, 6 Streptococcus pyogenes, 187 Haemophilus influenzae, 106 Moraxella catarrhalis, 126 Klebsiella pneumoniae, and 162 Pseudomonas aeruginosa). A total of 44 antibacterial agents, including 26 ?-lactams (four penicillins, three penicillins in combination with ?-lacta...
This paper reports the results of leaching experiments conducted with and without Thiobacillus ferroxidans at the same conditions in solution. The extent of leaching of ZnS with Bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, which no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shrinking-core model shows that the chemical leaching of ZnS is limited by the diffusion of ferrous ions through the sulfur product layer at high concentrations of ferrous ions. The analysis of the data shows that diffusion through the product layer does not limit the rate of dissolution when bacteria are present. This suggests that the action of T.ferroxidans in oxidizing the sulfur formed on the particle surface is to remove the barrier to diffusion by ferrous ions.
In situ synthesis of silver chloride (AgCl) nanoparticles was carried out under ambient conditions in nanoporous bacterial cellulose (BC) membranes as nanoreactors. The growth of the nanoparticles was readily obtained by alternating dipping of BC membranes in the solution of silver nitrate or sodium chloride followed by a rinse step. X-ray diffraction (XRD) patterns indicated the existence of AgCl nanoparticles in the BC and scanning electron microscopy (SEM) images showed that the AgCl nanoparticles well dispersed on the surface of BC and penetrated into the BC network. The AgCl nanoparticle-impregnated BC membranes exhibited high hydrophilic ability and strong antimicrobial activity against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive). The preparative proced...
Abstract The efficacy of iodine and glutaraldehyde as fish egg surface disinfectants were assessed in red porgy (Pagrus pagrus) and white sea bream (Diplodus sargus sargus) eggs, two species of interest for Mediterranean aquaculture. Iodine was effective in reducing the bacterial load of the 1-day-old eggs when applied at 50 mg L-1 for 5 min. The same concentration did not cause any significant change in hatching success or survival of the larvae for the first 5 days. Glutaraldehyde failed to reduce the bacterial load of the fish eggs at concentrations that were safe for the eggs (100 mg L-1 for 5 min), as it had a significant effect in preventing hatching of the developed embryo. Disinfecting 0-day-old eggs with iodine resulted in a significant reduction of hatching percentage, while larv...
In this study, bacterial strains were investigated in order to determine their heavy metal tolerance. The bacterial strains were identified as Bacillus cereus and Bacillus pumilus. In the batch system, the effects of operating variables such as solution pH, initial metal concentration, contact time, and adsorbent dosage were investigated. Both isolates were highly resistance to copper and lead in comparison with the control strain examined. The adsorption capacities of B. cereus and B. pumilus were found to be 22.1mg/g and 28.06mg/g, respectively. The biosorption follows pseudo-second order kinetics and the isotherm fits well to the Langmuir isotherm model. In column experiments, the biosorption was fitted well by the Thomas model. The breakthrough and exhaustion capacity of each biosorben...
Bacterial cellulose produced by the gram-negative bacterium Gluconacetobacter xylinum was found to be an excellent native starting material for preparing shaped ultra-lightweight cellulose aerogels. The procedure comprises thorough washing and sterilization of the aquogel, quantitative solvent exchange and subsequent drying with supercritical carbon dioxide at 40 degreeC and 100 bar. The average density of the obtained dry cellulose aerogels is only about 8 mg cm-3 which is comparable to the most lightweight silica aerogels and distinctly lower than all values for cellulosic aerogels obtained from plant cellulose so far. SEM, ESEM and nitrogen adsorption experiments at 77 K reveal an open-porous network structure that consists of a comparatively high percentage of large mesopores and small...
We compared an idealised mathematical model of the lower part of the pelagic food web to experimental data from a mesocosm experiment in which the supplies of mineral nutrients (nitrogen and phosphorous), bioavailable dissolved organic carbon (BDOC, as glucose), and silicate were manipulated. The central hypothesis of the experiment was that bacterial consumption of BDOC depends on whether the growth rate of heterotrophic bacteria is limited by organic-C or by mineral nutrients. In previous work, this hypothesis was examined qualitatively using a conceptual food web model. Here we explore the extent to which a ?simplest possible?? mathematical version of this conceptual model can reproduce the observed dynamics. The model combines algal?bacterial competition for mineral nutrients (phosphor...
The authors report here on an experimental study of heat transfer augmentation in turbulent flow. Enhancement strategies employed in this investigation are based on the near-wall mixing processes induced in the sublayer through appropriate wall and near-wall streamwise-periodic disturbances. Experiments are performed in a low-turbulence wind-tunnel with a high-aspect-ratio rectangular channel having either (a) two-dimensional periodic microgrooves on the wall, or (b) two-dimensional microcylinders placed in the immediate vicinity of the wall. It is found that microdisturbances placed inside the sublayer induce favorable heat-transport augmentation with respect to the smooth-wall case, in the near-analogous momentum and heat transfer behavior are preserved; a roughly commensurate increase in heat and momentum transport is termed favorable in that it leads to a ...
Quantitative gated SPECT (QGS) was evaluated in 7 normal volunteers and 31 patients with cardiac diseases. Adequate cut off value of a prefilter was 0.45. In phantom, the left ventricular volume value was 93.9% of determined value by 180-degree projection in L type and 98.8% by 360-degree projection in opposed type. In normal volunteers, LVEF measured by QGS program related to value by first pass method. As for functional map, regional EF and wall motion decreased at the septum side, and wall thickening at base side of heart. Good correlation was recognized (p<0.0001) between blood flow image and functional map (regional EF and wall thickening). In 20 cases of acute myocardial infarction, lesion was detected conspicuously in regional EF and wall motion. The accuracy of coronary arterial stenosis improved in functional map (regional EF 92%, wall motion 92% and ...
This paper summarises the main results obtained so far in the frame of the EU Home Team test programme of ITER primary wall small scale mock ups. It describes briefly the fabrication method of the mock ups, the test conditions and the main results obtained with high heat flux and thermal fatigue tests of Cu alloy/stainless steel and beryllium/Cu alloy/stainless steel mock ups. The results obtained so far show good thermal fatigue performance and operation margin of the ITER primary first wall concept. (author)
It is postulated that a break of a thin-walled pipe does not cause a subsequent break in the pipe in the vicinity of a plastic hinge even when the wall is weakened by a 60 circumferential crack of a depth of 30% of the wall thickness on the tension side. This pipe behavior is the result of plastic buckling in the compression side and applies to pipes of diameter-to-thickness ratio larger than 20. For this type of pipe, the axial strains decrease with increasing diameter-to-thickness ratio in the tension side. As the pipe is only loaded in one direction, there is no cyclic behavior that can trigger a subsequent break. (orig.)
This paper presents the main achievements of the European Home Team (EU HT) test programme of ITER primary wall small scale mock ups. It describes briefly the fabrication method of the mock ups, the test conditions and the main results obtained with high heat flux and thermal fatigue tests of Cu alloy/stainless steel and beryllium/Cu alloy/stainless steel mock ups. The results obtained so far show very good thermal fatigue performance and operation margin of the ITER primary first wall concept.
Several recent experiments on micro- (or nano-) structured samples of ferromagnetic materials are introduced. Magnetization reversal phenomena are investigated on submicron wire samples of trilayer structure using the giant magnetoresistance effect. Domain wall movements are sensitively monitored by resistivity measurements and the velocity of propagation is determined. The contribution of domain wall to the resistivity is argued from the results on artificially designed samples of a spring-magnet system. In circular dots of permalloy, the existence of vortex magnetization is confirmed and the reversal of the vortex core magnetization is studied from magnetic force microscopy measurements. (author)
We present evidence for the creation of an exchange spring in an antiferromagnet due to exchange coupling to a ferromagnet. X-ray magnetic linear dichroism spectroscopy on single crystal Co/NiO(001) shows that a partial domain wall is wound up at the surface of the antiferromagnet when the adjacent ferromagnet is rotated by a magnetic field. We determine the interface exchange stiffness and the antiferromagnetic domain wall energy from the field dependence of the direction of the antiferromagnetic axis, the antiferromagnetic pendant to a ferromagnetic hysteresis loop. The existence of a planar antiferromagnetic domain wall, proven by our measurement, is a key assumption of most exchange bias models.
The paper describes an analytical study of two parallel-flowing boundary layers of free and forced convection modes on the facing sides of a vertical thin wall. The two layers are analyzed separately within the framework of boundary layer theory, and coupled by the matching conditions at wall. Numerical data are obtained for a wide range of a dimensionless conjugation parameter {zeta} relating the heat transfer effectiveness of two convection modes. Based on these data, an expression for calculating the conjugate mean Nusselt number as a function of {zeta}-parameter is found by means of a curve-fitting method. (orig.)
An aspiration cover is proposed for the site of loading a belt conveyer including a housing arranged above the belt conveyer in whose cover there is an aspiration sleeve and a discharge chute from the upper wall and a guide having a cushioning plate on the lower end. It is distinguished by the fact that in order to improve the effectiveness of removing dust by decreasing the volume of aspirated air, the cover between the aspiration sleeve and the upper wall of the loading chute is convex in the inside of the housing and has a smooth connection to the upper wall of the discharge chute turned towards the cushioning plate.
... necessary to allow for the effata nr the finits size of the oressure tranaducer on both the root mean square and power spectral density measurements ...
screens of fine wire was placed between the gun barrel and the panel to determine whether the gun performance was repeatable. The transducers were placed ...
We demonstrate a novel cross-sectional deformation, called the radial corrugation, of multi-walled carbon nanotubes (MWNTs) under hydrostatic pressure. Theoretical analyses based on the continuum elastic approximation have revealed that MWNTs consisting of more than ten concentric walls undergo elastic deformations at critical pressure Formula Not Shown , above which the circular shape of the cross-section becomes radially corrugated. Various corrugation modes have been observed by tuning the innermost tube diameter and the number of constituent walls, which is a direct consequence of the core-shell structure of MWNTs. Cross-sectional views of MWNT under high hydrostatic pressure: elliptic deformation with the mode index n = 2 (left), and radial corrugations with n = 5 (center), and n = 6 ...
Morphological, Electrophysiological and Behavioral Investigations of the Nervous Tissue Developed from the Embryonic Matrix Zone Cells of the Dorsolateral Walls of Lateral Ventricles, Implanted into the Lesioned Regions of the Adult Rat's Brain
We study dipolar bosons in a 1D optical lattice and identify a region in parameter space---strong coupling but relatively weak on-site repulsion---hosting a series of stable CDW states whose low-energy excitations, built from "fractional domain walls", are remarkably similar to those of non-abelian fractional quantum Hall states. Here, a conventional domain wall between translated CDW's may split by inserting strings of degenerate, but inequivalent, CDW states. Outside these insulating regions, we find numerous supersolids as well as a superfluid regime. The mentioned phases should be accessible experimentally, and in particular, the fractional domain walls can be created in the ground state using single-site addressing, i.e. by locally changing the chemical potential.
was deemed adequate and a cooling system designed utilizing the Melcor CP2-15- 10B thermoelectric module. Wall temperature achieved with this system was - 36 ...
Accidents of free-rolling cars against walls with friction are special cases of the general problem of the dynamic behavior (elastic or plastic) of car motion. Using particle modeling of the car body it is shown that large rotations, contact friction and plastic deformations can be computed. Because of the limitations of FEM it is necessary to model the car as a system of mass points connected by central force systems which are non-linear. The wall is formulated as a rigid body producing constraints for the contacting particles, while the contact force is given by the defined force system. Every contacting particle produces a plastic impact on the wall. The friction force is proportional to the contact force and lies in the direction of the sliding velocity on the wall. Time integration is carried out using a second order Gear method. ((orig.))
Figure 23 presented detailed layout of the cooling system designed for the Mach 6 hypersonic- transport. The distribution system consisted of thin-wall ...
Using a quasi-static approach valid for Stefan numbers less than one, we derive approximate equations governing the movement of a phase change front for materials which generate internal heat. These models are applied for both constant surface temperature and constant surface heat flux boundary conditions, in cylindrical, spherical, plane wall and semi-infinite geometries. Exact solutions with the constant surface temperature condition are obtained for the steady-state solidification thickness using the cylinder, sphere, and plane wall geometries which show that the thickness depends on the inverse square root of the internal heat generation. Under constant surface heat flux conditions, closed form equations can be obtained for the three geometries. In the case of the semi-infinite wall, we show that for constant temperature and constant heat flux out of the wall conditions, the solidification layer ...
The authors describe an effect of suppression of invasion of the guinea pig eye conjunctiva and the HEp-2 epithelial cells by virulent Sh. flexneri bacilli, with a simultaneous administration of the same dose of avirulent shigella mutants, genetically connected with them. The data of morphological study and experiments with 3H-glucose labeled shigellae carried out on the cell species model indicated that the bacterial competition for the specific sites for absorption on the epithelial cells underlay the observed phenomenon. PMID:331774
Aerobic chemoheterotrophic bacteria were isolated from surface soils and coastal plain subsurface (including deep aquifer) sediments (depths to 265 m) at a study site near Aiken, S.C., by plating on...Full Text Available
Pseudomonas syringae is a gram-negative bacterial plant pathogen that is dependent on a type III protein secretion system (TTSS) and the effector proteins it translocates into plant...Full Text Available
Bacteriocins are an abundant class of antimicrobial molecules that appear to mediate population dynamics within species. The bacteriocins of Escherichia coli have served as a model for exploring the ecological role of these potent toxins. Studies suggest that colicins provide a competitive edge in nutrient-poor environments and that there might be a trade-off between the costs and benefits of colicin production. PMID:10203843
Our work is towards mechanistically understanding interactions of unsaturated bacterial biofilms and their extracellular polymeric substances (EPS) with actinide metals and metal surrogates under vadose zone conditions. Because metal contaminants in the vadose zone co-occur with organic pollutants, some of our work has included experiments with organic pollutants.
Tonsillar and nasal swabs were collected from weanling pigs in 50 representative Ontario swine herds and tested for the presence of 5 important bacterial upper respiratory tract pathogens. All but 1...Full Text Available
We introduce a discrete multiplicative process as a generic model of competition. Players with different abilities successively join the game and compete for finite resources. Emergence of dominant players and evolutionary development occur as a phase transition. The competitive dynamics underlying this transition is understood from a formal analogy to statistical mechanics. The theory is applicable to bacterial competition, predicting novel population dynamics near criticality.
Streptococcus pneumoniae colonizes the mucosal surface of the human upper respiratory tract. A colonization event is gradually cleared through phagocytosis by monocytes/macrophages that are recruited to the airway lumen. Here, we sought to define the bacterial and host factors that promote monocyte/macrophage influx and S. pneumoniae clearance using intranasal bacterial challenge in mice. We found that the recruitment of monocytes/macrophages required their expression of the chemokine receptor CCR2 and correlated with expression of the CCR2 ligand CCL2. Production of CCL2 and monocyte/macrophage recruitment were deficient in mice lacking digestion of peptidoglycan by lysozyme (LysM) and cytosolic sensing of the products of digestion by Nod2. Ex vivo macrophages produced CCL2 following bacterial uptake, digestion by LysM, and sensing of peptidoglycan by Nod2. Sensing of digested peptidoglycan by Nod2 also required the ...
The positive control function of the bacterial enhancer-binding protein NtrC resides in its central domain, which is highly conserved among activators of ς54 holoenzyme. Previous...Full Text Available
An Escherichia coli B strain, B834 galU56, has been isolated which supports growth of bacteriophage T4 with cytosine in its DNA while restricting growth of T4 with hydroxymethylcytosine. This host is...Full Text Available
Intrahepatic cholangiocarcinoma is the second most common primary malignant hepatic neoplasm. We describe two cases of intrahepatic cholangiocarcinoma which initially presented as liver abscess both clinically and radiologically. Mucin-hypersecretion from the tumor cells and extensive necrosis or secondary bacterial infection was responsible for the radiologic appearance of a liver abscess.=20
Staphylococcus aureus survives inside eukaryotic cells. Our objective was to assess the activity of NZ2114, a novel peptidic antibiotic, against intracellular S. aureus in comparison with established antistaphylococcal agents acting on the bacterial envelope with a distinct mechanism.
PurposeCoexistence of different classes of β-lactamases in a single bacterial isolate may pose diagnostic and therapeutic challenges. We investigated a spread of Klebsiella...Full Text Available
We sequenced 16S rRNA genes from the vaginal swab contents of a postmenopausal woman with asymptomatic bacterial vaginosis (BV). Sequences from Atopobium vaginae were the most commonly detected. In a survey of 35 other postmenopausal women, this organism was detected in 44% with BV but not in any subjects deemed healthy. PMID:15071062
Campylobacter spp. are present in the intestinal tract and internal tissues of broiler breeder and broiler chickens. Campylobacter spp. are known to cause acute bacterial gastroenteritis in humans and raw poultry products have been implicated as a significant source of these infections. The object...
BackgroundThe ability of catecholamines to stimulate bacterial growth was first demonstrated just over a decade ago. Little is still known however, concerning the nature of the putative...Full Text Available
BackgroundThermostable bacterial lipases occupy a place of prominence among biocatalysts owing to their novel, multifold applications and resistance to high temperature and other...Full Text Available
The authors solve the two-dimensional stefan problem of solidification in a half-space, where the heat flux at the wall is a slightly varying function of positioning along the wall, by means of a large Stefan number approximation (which turns out to be equivalent to a small time solution), and then by means of the Heat Balance Integral Method, which is valid for all time, and which agrees with the large Stefan number solution for small times. A representative solution is given for a particular form of the heat flux perturbation.
The change in concentrations of elements due to transmutations resulting from neutron irradiation in the first wall of the ARIES-IV conceptual fusion energy device were determined as a function of neutron dose. SiC burns out at a rate of about 0.5% per effective full power year. The largest impurity concentration is that of He, but several other elements burn in at rates of hundreds of appm/efpy.
... The composite ground floor is suitable for support to all types of wall construction and can be used equally well on strip footings or mini-pile foundations . The light steel edge beams provide the accurate template required for internal timber or light steel wall frames to minimise fitting time and eliminate rework. The floated slab surface will accept floor finishes directly and thermal insulation can be easily fitted beneath ...
In this work, the thermal performance of a conventional collector is improved by inserting porous substrates at the inner walls of the collector tubes. The porous substrates improve the convective heat transfer coefficient between the tube wall and the fluid. This improvement is investigated numerically and its effects on the efficiency and the useful gain of the collector are evaluated. It is found that inserting the porous substrate may raise the collector efficiency considerably, especially at high values of the overall heat loss coefficient.
The effectiveness of an acrylic latex wall sealant in limiting the escape of radon from rock in underground mines is the subject of this paper. Application of the latex as a two-coat system over a fillter coat of gunite produced a reduction of radon concentration from an initial level of 80 to 100 pCi/L to a final average of 25 to 30 pCi/L under similar conditions.
...direct-injection systems Atomisation from hole-type nozzles (gasoline and diesel) under cavitating flow conditions Spray-wall interaction in gasoline direct injection engines Spray-wall interaction in direct-injection diesel engines Evaporation of multi-component fuels Cavitation in diesel injectors Nozzle flow, air motion, spray development and combustion in marine diesel engines ...
Analytical solutions are derived for a flow in a semi-infinite vertical porous medium with heat and mass transfer. When the temperature and mass concentration are uniform a constant pressure is possible and sustains a fully developed flow. Thereafter there is a small perturbation on the wall temperature and concentration and the subsequent two-dimensional problem is tackled for a large Prandtl number, free convection parameters and small Reynolds number. The heat transfer rate at the wall is discussed quantitatively.
We report on the fouling of Focused Ion Beam (FIB)-fabricated silicon oxide nanopores after exposure to tap water for two weeks. Pore clogging was monitored by Scanning Electron Microscopy (SEM) on both bare silicon oxide and chemically functionalized nanopores. While fouling occurred on hydrophilic silicon oxide pore walls, the hydrophobic nature of alkane chains prevented clogging on the chemically functionalized pore walls. These results have implications for nanopore sensing platform design.
Ti honeycombs with the side of 800 and 400 nm were fabricated by focused ion beam (FIB), though the surfaces of the bottom and wall of the Ti honeycombs were rough, as compared with the surfaces of the bottom and wall of the Si honeycomb. It is demonstrated that the nanoscale Ti components can be fabricated in a short time by FIB.
Small scale mock-ups of the primary first wall, the baffle first wall, the shield block and a partial model for the edge of the primary first wall module were designed and fabricated incorporating most of the key design features of the ITER shielding blanket. All mock-ups featured the DSCu heat sink, the built-in SS coolant tubes within the heat sink and the SS shield block. CFC tiles was used as the protection armor for the baffle first wall mock-up. The small scale shield block mock-up, integrated with the first wall, was designed to have a poloidal curvature specified in the ITER design. Fabrication routes of mock-ups were decided based on the single step solid HIP of DSCu/DSCu, DSCu/SS and SS/SS reflecting the results of previous joining techniques development and testing. For attaching the CFC tiles onto DSCu heat sink in the fabrication of the baffle first ...
The Doublet III device is operating with an extensive system of plasma limiters and wall protective armor. Operations with up to 8MW of neutral beam power and 1.5MA plasma current are planned. Design and operational performance of the following systems are discussed: 1. Water-cooled graphite moveable limiter. 2. Water-cooled graphite fixed limiter and neutral beam wall armor. 3. Radiatively cooled Inconel divertor plates.
A side terminal battery is described comprising: a casing having a side wall made from a moldable material; and a plug formed of relatively deformable, electrically conductive, corrosion resistant material molded into the side wall to form a seal between the interior and exterior of the casing and including a battery terminal insert embedded therein so as to be exposed at the exterior of the casing and isolated, by the plug, from the interior of the casing.
During the operation of a tokamak, the first wall elements suffer very high heat fluxes. Heat is removed by internal cooling by means of water, helium or fluid metal. The resulting inhomogeneous temperature field cause internal stresses which, due to the pulsed operation are of cyclic nature. Additional mechanical stresses in the first wall may be caused by disruptions or vertical plasma movements. During theses events high currents are induced in the metallic part of the first wall which by their interaction with the magnetic field of the tokamak lead to mechanical forces. These electromechanical stresses may lie beyond the yield stress of the structural material. From the interaction of thermal and mechanical forces, a complex stress state is achieved which under certain circumstances may lead to premature failure and/or to progressive plastic deformations (ratcheting). In order to study the boundary conditions for the ...
Device for separating and collecting ultrafine atomized powder from the gas stream of a gas atomizing apparatus comprises a housing having an interior wall oriented at an angle relative to horizontal so as to form a downwardly converging, conical expansion chamber, an inlet conduit communicated to the expansion chamber proximate an upper region thereof for receiving the gas stream, and an outlet proximate a lower region of the expansion chamber. The inlet conduit is oriented at a compound inclined angle (with respect to horizontal) selected to promote separation and collection of powder from the gas stream in the expansion chamber. The compound angle comprises a first entrance angle that is greater than the angle of repose of the powder on the housing interior wall such that any powder accumulation in the inlet conduit tends to flow down the wall toward the outlet. The second angle is selected generally equal to the angle ...
This report presents the thermal-hydraulic analysis of four Loss-of-Flow Accidents (LOFAs) in the first wall/blanket cooling system of the alternative SEAFP reactor design. The LOFAs considered result from a loss of electrical power for the recirculation pump in the primary cooling circuit. The analyses have been performed using the thermal-hydraulic system analysis code RELAP5/MOD3. In the analyses, special attention has been paid to the transient thermal-hydraulic behaviour of the cooling system and the temperature development in the first wall and blanket. For the LOFA without plasma shutdown, significant loss of heat removal due to dryout occurs at the midplane of the outboard first wall cooling pipes about 41 s after pump trip. For the three LOFA cases with emergency plasma shutdown that have been studied, the temperature increase in the Be-coating at the midplane of the outboard first wall is ...
Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important component of reactor safety in case of accidents. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the GDH into the ECCS. The GDH that is propelled into motion after a guillotine break can impact neighboring GDH pipes or the nearest wall of the compartment. Therefore, two cases are investigated: GDH impact on an adjacent GDH and its attached piping; and GDH impact on an adjacent reinforced concrete wall. A whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is modeled using finite elements. The finite element code NEPTUNE used in this study enables a dynamic pipe whip structural analysis that accommodates large displacements and nonlinear material ...
To assess the potential of CT in evaluating the histological severity of acute appendicitis in comparison with surgical and pathological findings. The CT images of 75 patients with surgically proven appendicitis, including 10 cases of catarrhal, 34 of phlegmonous, and 31 of gangrenous appendicitis, were retrospectively analyzed for the following five CT findings: hazy periappendiceal densities, enlarged appendix, increased enhancement of the appendiceal wall, increased enhancement of the periappendiceal intestinal wall, and deficiency of the appendiceal wall. By comparing all the CT findings and the pathological severity of appendicitis (catarrhal, phlegmonous, and gangrenous), the prevalence of the five CT findings was calculated for each pathological category. Abnormal CT findings were noted in only one case of catarrhal appendicitis. Increased enhancement of the appendiceal wall was observed in all ...
Research highlights: #-># Morphological and chemical characterization at atomic scale of porous alumina layers anodised in ordered regimes. #-># Characterization based on the use of FEG-SEM, STEM-HAADF, STEM-EELS and STEM-X-EDS. #-># Nanoscale distribution of P-, C- and S-bearing species in the pore wall. - Abstract: Ordered porous alumina layers prepared by two-step anodising in phosphoric, oxalic and sulphuric acids have been characterized at sub-nanometer scale using electron microscopy techniques. FEG-SEM and STEM-HAADF images allowed estimating the pore size, cell wall and pore wall thicknesses of the layers. Nanoanalytical characterization has been performed by STEM-EELS and STEM-X-EDS. Detailed features of the spatial distribution of anions in the pore wall of the films have been obtained. Maximum concentration of P-species occurs, approximately, at the middle of the pore ...
This paper introduces the JNM Special Issue on the development of a first wall for the reaction chamber in a laser fusion power plant. In this approach to fusion energy a spherical target is injected into a large chamber and heated to fusion burn by an array of lasers. The target emissions are absorbed by the wall and encapsulating blanket, and the resulting heat converted into electricity. The bulk of the energy deposited in the first wall is in the form of X-rays (1.0-100 keV) and ions (0.1-4 MeV). In order to have a practical power plant, the first wall must be resistant to these emissions and suffer virtually no erosion on each shot. A wall candidate based on tungsten armor bonded to a low activation ferritic steel substrate has been chosen as the initial system to be studied. The choice was based on the vast experience with these materials in a nuclear environment and the ...
Biofumigation with Muscodor albus was investigated to control four fungal decay pathogens (Phytophthora erythroseptica, Sclerotinia sclerotiorum, Botrytis cinerea and Penicillium expansum) and four bacterial pathogens (Erwinia carotovora pv. carotovora, Pseudomonas fluorescens, Escherichia coli, Listeria innocua) in controlled atmosphere conditions (regular air (20.8% O2+0.03% CO2), high CO2 (20.8% O2+15% CO2) or low O2 (1% O2+0.03% CO2)). In vitro experiments involved 48h exposure to M. albus at 3degreeC or 20degreeC, in vivo experiments involved 72h exposure to M. albus at 3degreeC. In vitro biofumigation with M. albus in regular air at 20degreeC killed all the pathogens. Bacterial growth was best controlled by M. albus at 20degreeC regardless of atmospheric conditions whereas fungal gro...
Products of a power plant flue gas desulfurization scrubber are discharged into a pond as sludge consisting of calcite (initial delta13C 3.2-3.8 per thousand), gypsum (initial delta34S 7.6-8.6 per thousand), and aqueous solution. Reducing conditions exist below a boundary that appears to move vertically as a function of changes in pond water level. Under reducing conditions, bacteria partially reduce aqueous sulfate to low-delta34S sulfide, consuming organic carbon and generating low-delta13C bicarbonate. Under oxidizing conditions, sulfide is converted to sulfate, leading to calcite dissolution, gypsum precipitation, and isotopic re-equilibration of remaining calcite with dissolved bicarbonate near the pond surface. The gypsum has delta34S near 6 per thousand, and calcite has delta13C as low as -1.7 per thousand; the changes from initial values correspond to predictions based on isotopic balance and reaction stoichiometry. The pond largely contains the products of ...
This randomized, placebo-controlled, double blind, parallel dose-response study investigated the impact of 4-week commercial yoghurt consumption supplemented with Bifidobacterium animalis subsp. lactis (BB-12) and Lactobacillus acidophilus (LA-5) on fecal bacterial counts of healthy adults. Fifty-eight volunteers were randomly assigned to three different groups: 1. placebo (no probiotic, no starter and no green tea extract); 2. Yoptimal (10^9cfu/100g of BB-12 and LA-5 and 40mg of green tea extract) and 3. Yoptimal-10 (10^1^0cfu/100g of BB-12, 10^9cfu/100g of LA-5 and 40mg of green tea extract). These yoghurt products also contained Lactobacillus delbrueckii subsp. bulgaricus (10^7cfu/100g) and Streptococcus thermophilus (10^1^0cfu/100g). The quantitative PCR (qPCR) results showed that ther...
The origin of natural gas in the Japanese oil and gas fields are geochemically studied. Samples are taken from structural natural gas, surface gas seepage, water-dissolved natural gas and coal-field gas of the Japan Sea coast area. The origins of primary hydrocarbons are classified into bacteria gas and thermogenic gas, the latter being subclassified into gas in oil production zone with the per million deviation of the carbon isotope (/sup 13/C/sup 1/) of methane less than -35 and those gases with maturity higher than this. Surface gas seepage is subjected to migration and bacterial oxidation. Coal gas is similar to oil gas. The CO/sub 2/ concentration is 0 - 2% and /sup 13/CO/sub 2/ deviations from -30 - +30. The origin can be barely estimated from the isotopic composition because of the wide secondary change in the composition. The origin and migration of gas from the gas field of northern Niigata are not similar to those in the southern area, which consist of a ...
Objective To compare the levels of interleukin (IL)-1?, IL-6, and matrix metalloproteinase (MMP)-8 in the vaginal secretions of pregnant women with a positive fetal fibronectin (fFN) test result with or without asymptomatic bacterial vaginosis (BV) before and after treatment with oral clindamycin. Methods A prospective cohort study was conducted among 43 pregnant women with a positive fFN test result. All patients were treated with clindamycin, and the pre- and post-treatment levels of IL-1?, IL-6, and MMP-8 were compared. Results Before treatment, levels of IL-1? and MMP-8 were significantly higher in women with BV compared with women without BV (P<0.05). Vaginal levels of IL-1? and IL-6, but not MMP-8, decreased after treatment in pregnant women with BV. Conclusions The inability of clin...
The genus Conexibacter (Monciardini et al. 2003) represents the type genus of the family Conexibacteraceae (Stackebrandt 2005, emend. Zhi et al. 2009) with Conexibacter woesei as the type species of the genus. C. woesei is a representative of a deep evolutionary line of des-cent within the class Actinobacteria. Strain ID131577T was originally isolated from temperate forest soil in Gerenzano (Italy). Cells are small, short rods that are motile by peritrichous fla-gella. They may form aggregates after a longer period of growth and, then as a typical charac-teristic, an undulate structure is formed by self-aggregation of flagella with entangled bacteri-al cells. Here we describe the features of the organism, together with the complete sequence and annotation. The 6,359,369 bp long genome of C. woesei contains 5,950 protein-coding and 48 RNA genes and is part of the Genomic Encyclopedia of Bacteria and Archaea project.
A nonlinear mathematical model is presented of a WWER-440 nuclear power plant horizontal steam generator. On the proposed model is based a computer program for investigating transients in steam generators during loss of coolant accidents. Processes taking place at the primary side of the steam generator are described by a set of partial differential equations while those at the secondary side of the steam generator are described by plain differential equations with the variables being complex time functions. The model takes account of the coolant as both a single- and two-phase medium, of changes in the direction of the primary coolant flow and of changes in the direction of heat transfer. Heat transfer through the wall is based on a simple model of heat transfer through a thin-walled tube and includes a correction for the heat resistance of the wall. (author).
Based on the CFD-code FLUENT trademark, theoretical studies were conducted of the influences of incineration chamber geometry (direct, countercurrent and center flow) on the combustion process. The boundary conditions, e.g., the thermal input and the waste grate, were kept constant. Close attention was paid to the distribution of flow, spe-cies, and temperatures. In addition, the influence of a dis-placement body at the end of the combustion chamber was tested. The variation of different wall materials and the prediction of problem areas concerning corrosion, slagging, and contamination completed the studies. Close to the chamber walls, high CO-concentrations may indi-cate corrosion; particle flow may indicate where contami-nation, slagging or erosion could occur. (orig.)
A new kind of receiver-reactor for high-temperature solar furnaces is proposed. The main body of the receiver component is an ellipsoid of revolution with specularly reflecting inner walls. The reactor component, a crucible, is placed at one focal point and the aperture at the other. With this arrangement, substantially all of the incident radiation from the concentrator should reach the reactor directly or after one reflection from the cavity walls. An analysis of the radiative exchange among the surfaces is presented. The analysis provides a tool for a parametric study and optimization of the design. It is found that, in contrast to that of conventional well-insulated cavity receivers, its collection efficiency is not very sensitive to the size of its aperture.
Heat transfer experiments were performed in the post-CHF two-phase flow regime in a vertical tube. The tube inside diameter was 7.75 mm, and the boiling fluid was R-113. The experiments were performed at steady state by means of liquid heating of the test tube. Wall superheats were maintained below 70 C for heat exchanger/steam generator application. The mass flux range of the data was 379-816 kg m{sup -2} s{sup -1}. The use of R-113 significantly extended the property range of the existing low wall-superheat data base. Experimental data are presented in tabular as well as graphical form, and the results were used with low wall-superheat data from other fluids to add generality to a predictive heat transfer correlation. (orig.)
In this paper, four different types of pulsed eddy current (PEC) probe are designed and their performance of detecting wall thickness reduction is compared. By using the backward difference method in time and the finite element method in space, PEC signals from various thickness and materials are numerically calculated and three features of the signal are selected. Since PEC signals and features are obtained by various types and sizes of probe, the comparison is made through the normalized features which reflect the sensitivity of the feature to thickness reduction. The normalized features indicate that the shielded reflection probe provides the best sensitivity to wall thickness reduction for all three signal features. Results show that the best sensitivity to thickness reduction is achieved by the peak value, but also suggest that the time to peak can be a good candidate because of its linear relationship with the thickness variation.
Combined gas and steam turbine processes based on direct coal firing show a high thermal efficiency. At RWTH Aachen, University of Technology, an experimental test furnace has been built to investigate the pressurized pulverized coal combustion (PPCC). The PPCC-facility has been constructed as a slag tap furnace. Particles hitting the walls at temperatures above the melting point cause slagging depositions and create a film flowing down the reactor walls. As a part of the PPCC-program different mathematical models have been developed and implemented into the CFD-code FLUENT to predict the behavior of slag films at the furnace walls. Numerical strategies and the mathematical models used are described in detail. 12 refs., 9 figs.
The evaluation of calculated values determined by means of the equations given in the TRD 300/301 standard resulted in two nomographs by which it is possible to find the theoretical wall thickness of cylinder shells without cutouts and branches as well as cylinder shells with an inclined or vertical single branch without additional thickening. The equations for the calculation of cylinder shells with an inclined single branch according to TRD 301 having only an iterative solution, the nomographs will be a considerable help for the engineering work. The determination of the theoretical wall-thickness from the nomographs is demonstrated by means of examples.
The present work summarizes efforts on the simulation of natural convection cooling within the IFMIF target and test cell. The simulations have been performed with the STAR-CD code using the k-#omega# high-Reynolds number turbulence model. A dedicated thermohydraulic model has been devised including Lithium loop components. Nuclear heat production has been calculated by the Monte-Carlo code McDeLicious for different parts of the target and test cell walls and was used as input for the STAR-CD simulations. Helium atmospheres at several pressures from 0.1 to 10"-"5 MPa have been investigated. In order to limit the maximum temperature of the concrete walls to 80 deg. C it was necessary to add thermal insulation layers to the hot Lithium loop surfaces and a conceptual system of two cooling layers in different depths of the concrete walls.
Lateral plume dispersion in deep river valleys during neutral and stable lapse rate conditions can be exceptionally high due to the intense horizontal turbulence generated by prominent variations in the width, orientation and surface roughness of the valley walls. Use of the standard Gaussian dispersion equation to represent this enhanced lateral plume spread in a narrow valley may be inappropriate since consideration should also be given to the restriction of the horizontal plume spread due to impingement against the valley walls. The basic concept employed in the modification of the Gaussian dispersion equation was to assume that multiple eddy reflections occur between the valley walls in a manner similar to the vertical eddy reflections between the ground plane and an inversion layer aloft. The expressions are developed, but no attempt has been made to validate them with actual measured field data. 4 references, 3 ...
In the frame of the Primary Wall Module prototype manufacturing for ITER, a consistent R and D phase was conducted in order to identify the industrial allowable tolerances and manufacturing problems which would occur when joining pieces by HIPping process during the PW module manufacturing. The purpose of this development was to give as industrial as possible manufacturing routes for joining together large Stainless Steel or DS-Copper pieces with Stainless Steel tubes and for bonding Beryllium tiles onto a curved component surface. The study concerned surface preparations, allowable gaps and joint geometry, Beryllium tile geometry, Titanium interlayer thickness, etc. This R and D phase also allowed the development and validation of different ultrasonic inspection tools needed for plate-plate, tube-plate, edge to edge plate bonding.
The local heat transfer coefficient distribution of a square channel with two opposite ribbed walls was determined. The square channel was connected to a sudden contraction entrance in order to simulate the inlet condition of the turbine blade cooling passages. The test channel was heated by thin stainless steel foils with a thickness of 0.000025 m, and instrumented with 180 thermocouples. The brass ribs of a square cross-section were glued periodically, in line, onto the top and bottom walls of the foil-heated channel in patterns to achieve the desired spacing and angle-of-attack. The local heat transfer coefficients on the smooth side and the ribbed side walls, at the channel entrance and the downstream regions, were measured for eight rib configurations and three Reynolds numbers (Re = 10,000, 30,000, and 60,000).
The concepts of general flow and thermal boundary conditions are introduced to treat the interaction between indoor and outdoor thermal environments in computational fluid dynamics (CFD) simulations. The results from a multi-zone model are used to supply the general flow boundary conditions. The energy balance equation at wall-air interfaces is used to supply the general thermal boundary conditions. An example calculation in a 13-room building shows that infiltration influences indoor air flow patterns considerably. The air flow in a room ventilated by displacement is measured and simulated. Two surface coatings are considered, i.e. black walls and aluminum walls. Implementation of these two boundary conditions is essential in predicting air flow patterns, air quality, and thermal comfort in a real building. (author)
In order to develop the filler metal for Hastelloy alloy XR structure with thick wall, the weldability and high temperature strength properties of Hastelloy alloy XR weldment were investigated using the filler metals, which were alloy-designed on the basis of multiple regression analysis. The former was examined through the chemical analysis in the deposited metal, bend test, FISCO cracking test, optical microscopy and hardness measurement. The latter was investigated by means of tensile and creep test. It was found from these results that the crack susceptibility in the weldment was apparent to be lowered without degrading the high temperature strength properties. Therefore, it is concluded that these filler metals possess excellent performance as the filler metal for Hastelloy alloy XR structure with thick wall. (author).
The unburned HC in a direct-injection diesel engine is a cause of exhaust odor and SOF emission. Reduction of HC by changing the injection nozzle specifications was attempted in previous studies. In this study, some experiments in which the mixture formation was varied by using different hole diameters in a multihole nozzle and spray angles to the combustion chamber wall have been conducted. When the diameter of injection holes, which influences the fuel adhering to on the cylinder head walls and the combustion chamber wall, becomes smaller, the HC emission in the idling condition, HC deviation from cylinder to cylinder and HC increase with long idling time are decreased. The same effects were obtained by decreasing the diameter of all holes and by injecting the spray downward to the combustion chamber. 13 refs., 13 figs., 1 tab.
The distribution of the central benzodiazepine receptor specific ligand iodine-123 iomazenil was investigated in seven human adults from whole-body scans, blood samples and urine collected up to 24 h after injection. Using 12 source organs, the MIRD method was applied to calculate the absorbed radiation dose of the radioligand in various organs. The urinary bladder wall (0.15 mGy/MBq), lower large intestinal wall (0.071 mGy/MBq) testes (0.044 mGy/MBq) and upper large intestined wall (0.038 mGy/MBq) received the highest absorbed doses. The average effective dose equivalent of "1"2"3I-IBZM for adults was estimated to be 0.033 mSv/MBq. (orig.).
A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface.
A dielectric-wall linear accelerator is improved by a high-voltage, fast rise-time switch that includes a pair of electrodes between which are laminated alternating layers of isolated conductors and insulators. A high voltage is placed between the electrodes sufficient to stress the voltage breakdown of the insulator on command. A light trigger, such as a laser, is focused along at least one line along the edge surface of the laminated alternating layers of isolated conductors and insulators extending between the electrodes. The laser is energized to initiate a surface breakdown by a fluence of photons, thus causing the electrical switch to close very promptly. Such insulators and lasers are incorporated in a dielectric wall linear accelerator with Blumlein modules, and phasing is controlled by adjusting the length of fiber optic cables that carry the laser light to the insulator surface. 12 figs.
Infant mice were used to measure the amount of fluid accumulation (enterosorption) in the intestinal tract after oral inoculation of a porcine strain of enteropathogenic Escherichia coli (K88-+, Ent-+). Significant reduction in the amount of fluid found in the intestinal tract was observed if the mice were first inoculated with a K88-possessing, non-enterotoxigenic strain of E. coli. The protection provided is thought to be due to specific competition for attachment sites on cells of the small intestine. PMID:1095492
The effect of UV radiation in the wavelength region 230 nm to 302 nm on the ability of an irradiated mammalian cell to reactivate UV-irradiated mammalian virus was tested. An action spectrum for radiation enhanced reactivation (RER) is presented. The shape of the action spectrum points to a combined nucleic acid-protein target for UV radiation effects on this cellular parameter. An analysis of the results of others involving the biochemical and photobiological events involved in RER does not allow us to distinguish which macromolecule is the major contributor to this effect. Studies involving an analogous phenomenon in bacteris (Weigle reactivation) imply that RER and WR amy involve similar mechanisms. (author).
Papers in this book illustrate the utility of mineral biotechnology with respect to biobeneficiation, bioleaching, bioremediation and biomineralization. Papers of particular interest to the coal industry include: depression of pyrite flotation by yeast and bacteris (S.K. Kawatra and T.C. Eisele); desulfurization of coal by microbial flotation in a semicontinuous system (T. Nagaoka and others); biochemical removal of HAP precursors from coal - INEEL slurry column testing (K.S. Noah and G.J. Olson); microorganisms, biotechnology and acid rock drainage - emphasis on passive-biological control and treatment methods (N. Kuyucak); and utility of bioreagents in mineral processing (P. Somasundaran and others).
The microbial safety of foods cooked in microwave ovens was investigated. The mechanisms of microwave destruction of microorganisms were examined. Effects of time and temperature on microorganisms in different food systems were described. Studies showed that: microwave heating of food is more ''''food dependent'' than conventional heating; recommended microwave treatment time for some foods may not destroy high levels of bacteria; use of microwaves in combination with conventional heating methods results in more uniform heating of foods and destruction of bacteria; and microwaves exert different killing effects on individual bacterial species. (78 references, 2 tables)
The analgesic, dipyrone (1,phenyl-2,3-dimethyl-5-pyrazolone-4-methylamino methane sulphonate sodium), at 20 mM concentration, inhibited the rejoining of single-strand scissions in DNA of Escherichia coli B/r cells induced by 20 krad gamma-radiation. The chemical altered the cell membrane structure as evidenced from the uptake of acriflavin, the efflux of potassium ions from the bacterial cells and the inhibition of alkaline phosphatase-a cell membrane associated enzyme. (author). 18 refs., 6 figures.
The analgesic, dipyrone (1,phenyl-2,3-dimethyl-5-pyrazolone-4-methylamino methane sulphonate sodium), at 20 mM concentration, inhibited the rejoining of single-strand scissions in DNA of Escherichia coli B/r cells induced by 20 krad gamma-radiation. The chemical altered the cell membrane structure as evidenced from the uptake of acriflavin, the efflux of potassium ions from the bacterial cells and the inhibition of alkaline phosphatase-a cell membrane associated enzyme. (author).
Summary Although many antibiotics are available for the treatment of bacterial infections, the emergence and global spread of antibiotic-resistant bacteria is a community-wide problem. To overcome this problem, we must explore alternative antimicrobials. This study investigated the antibacterial properties of quercetin, a flavonoid present in vegetables and fruits. Quercetin was tested against gram-positive and gram-negative bacteria and was found to exert selective antibacterial activity against Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), and Staphylococcus epidermidis. Some clinical MRSA strains showed remarkable susceptibility to quercetin. In combination with antibiotics, such as oxacillin, ampicillin, vancomycin, gentamicin, and erythromycin, quercetin sho...
Sulfur K-edge X-ray absorption spectroscopy is a powerful in situ probe of sulfur biochemistry in intact cells and tissues. Under favorable circumstances the technique can provide quantitative information on the chemical identify of the sulfur species that are present in a sample. Prange et al. have recently reported an X-ray absorption spectroscopic study of bacterial sulfur storage globules. Unfortunately there are substantial problems with the experimental technique employed that, they contend, lead to completely erroneous conclusions. In the more recent of their two papers Prange et al. employed a curve-fitting method similar to that used by us (for more than 10 years). In essence, the method employs simply fitting a linear combination of the spectra of standard compounds to that of the unknown, in this case cultures of bacterial cells. This type of analysis can provide quantitative estimates of the individual sulfur types in the sample, ...
Objective: To determine whether asymptomatic bacterial vaginosis (BV) is associated with upper genital tract inflammation or bacterial colonization.Methods: Fifty nonpregnant women with intact uteri who planned to undergo gynecologic surgery and had no recent symptoms of vaginal infection were enrolled. We obtained a vaginal swab for Gram stain, endocervical swab for chlamydia and gonorrhea DNA probe testing, and Pipelle endometrial biopsy for aerobic and anaerobic cultures and histology. We correlated surgical findings and histology of available surgical specimens with the microbiologic results. The diagnosis of BV was made according to Speigel's criteria. Bacteria isolated from the uterus were classified as high virulence versus low virulence. Contingency tables were analyzed using the chi-square or Fisher Exact tests.Results: Twenty-one of 50 patients had BV on Gram stain, 3 had intermediate BV, and 3 had unreadable slides. Eleven patients ...
This thesis contains the candidate's original work on excitonic structure and energy transfer dynamics of two bacterial antenna complexes as studied using spectral hole-burning spectroscopy. The general introduction is divided into two chapters (1 and 2). Chapter 1 provides background material on photosynthesis and bacterial antenna complexes with emphasis on the two bacterial antenna systems related to the thesis research. Chapter 2 reviews the underlying principles and mechanism of persistent nonphotochemical hole-burning (NPHB) spectroscopy. Relevant energy transfer theories are also discussed. Chapters 3 and 4 are papers by the candidate that have been published. Chapter 3 describes the application of NPHB spectroscopy to the Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Prosthecochloris aestuarii; emphasis is on determination of the low energy vibrational structure that is important for ...
Immidacloprid is a cyclodiene organochlorine used as an insecticide all over the world and possessing a serous environmental threat. It is mostly used for cotton insects (bollworm, aphid and white fly). For isolation of imidacloprid degrading bacteria, two soil samples were collected from industrial contaminated sites of Kala Shah Kahu district sheikupura, having ten year history of use. Soil samples were analyzed by measuring pH and electric conductivity. The isolation of imidacroprid degrading bacteria was performed by enrichment technique. Eight bacterial strains, S/sub 1-a/ S/2-2-b/ S/2-c/ S/2-d/ S/2-e/ S/sub 2-f/ and S/sub 2-g/ and S/sub e-a/ were isolated on the basis of their colony morphologies. The purified colonies were characterized morphologically, physiologically and biochemically. Gram staining was done and Gram negative strain were confirmed on MacConkey agar and Eosin Methylene Blue. Bacterial strains were also checked for ...
Spice extracts under the form of essential oils were tested for their efficiency to increase the relative radiosensitivity of Listeria monocytogenes and Escherichia coli O157H7 in culture media. The two pathogens were treated by gamma-irradiation alone or in combination with oregano essential oil to evaluate their mechanism of action. The membrane murein composition, and the intracellular and extracellular concentration of ATP was determined. The bacterial strains were treated with two irradiation doses: 1.2 kGy to induce cell damage and 3.5 kGy to cause cell death for L. monocytogenes. A dose of 0.4 kGy to induce cell damages, 1.1 kGy to obtain viable but nonculturable (VBNC) state and 1.3 kGy to obtain a lethal dose was also applied on E. coli O157H7. Oregano essential oil was used at 0.020% and 0.025% (w/v), which is the minimum inhibitory concentration (MIC) for L. monocytogenes. For E. coli O157H7, a concentration of 0.006% and 0.025% (w/v) which is the ...
The wavenumber-frequency spectral densities of turbulent wall pressure fluctuations are investigated over a rigid flat plate. Nonlinear Reynolds stress terms of the inhomogeneous Orr-Sommerfeld equation are regarded as a known forcing function. The forcing function is modeled after Bark{close_quote}s hydrodynamic bursting formulation. The inhomogeneous Orr-Sommerfeld equation is solved by the method of Eckhaus in terms of discrete homogeneous solutions. The method of Eckhaus is then extended and proved for the continuous Orr-Sommerfeld eigenfunctions. Turbulent wall pressure fluctuations in terms of wavenumber-frequency spectral densities are numerically computed and compared to the experimental results of Martin as well as to his transformation of Blake{close_quote}s data fitted to a modified Corcos model. The wavenumber-frequency spectral densities numerically computed from the discrete eigenfunctions compared well with Martin{close_quote}s ...
The present design of Blanket Shield and Primary Wall for ITER envisages construction of the wall with a water cooled, stainless steel outer layer and a water cooled, copper liner on the inside plasma facing surface. Protection of the inner copper surface with an armour layer is necessary to cope with plasma to wall interaction. There are a number of armour materials under consideration, for this project beryllium was used. The scope of work was to produce a series of mock-ups, each consisting of a different combination of materials, which included Dispersion Strengthened Copper, Copper-Chrome-Zirconium alloy, Beryllium and Stainless Steel. Hot Isostatic Pressing (HIP) was the method used to ensure that a fully diffused bonded joint was achieved giving the necessary strength and thermal conductivity. The first five of the mock ups have been successfully completed and are being tested at the various laboratories in Europe. ...
Dominant mutations in sarcomere protein genes cause hypertrophic cardiomyopathy, an inherited human disorder with increased ventricular wall thickness, myocyte hypertrophy, and disarray. To understand...Full Text Available
The cell wall envelopes of gram-positive bacteria represent a surface organelle that not only functions as a cytoskeletal element but also promotes interactions between bacteria and their environment....Full Text Available
Partial bladder outlet obstruction (PBOO) induces remodeling of urinary bladder smooth muscle (detrusor). We demonstrate an increase in bladder wall mass, muscle bundle size, and a threefold increase...Full Text Available
A regulatory locus on the Staphylococcus aureus chromosome, designated sar, is involved in the expression of cell wall proteins, some of which are potentially important in the pathogenesis of endocarditis....Full Text Available
The author describes the layout of the environmental monitoring scheme at Devco's No. 26 Colliery in Canada, which includes wall face ventilation, fan performance, and methane drainage monitoring. He gives details of the sensors, outstations, and the surface control room.
The radiation method has been employed for the modification of the surface of vascular prostheses by means of acrylamide. As a result of the treatment, the tightness of the prosthesis walls was improved as well as an increase of surface hydrophilicity. Upon autoclaving, stable binding of polyacrylamide to prostheses is achieved. (author).
The properties of an atypical Brucella strain isolated from lymph node tissue of a cow slaughtered as a brucellosis reactor were examined. The organism was Gram negative and highly pleomorphic, existing...Full Text Available
Mycolic acids are key cell wall components for the survival, pathogenicity, and antibiotic resistance of the human tubercle bacillus. Although it was thought that Mycobacterium tuberculosis...Full Text Available
In Canada, the cost of heating is a major expense in the operation of greenhouses in the winter season, inhibiting greenhouse production in winter months in most part of the country. Alternative energy sources, such as solar energy and biomass energy may offer an economically feasible heating alternative. A solar energy greenhouse technology developed in northern China for winter vegetable production has demonstrated good potential for Manitoba winter conditions. The design and performance of solar energy greenhouses depend on the geographical location. Therefore, in order to optimize the design of solar greenhouses with respect to the latitude of the location for maximum solar radiation gain, a theoretical analysis was performed that analyzed parameters such as greenhouse length and the roof slope. This paper described the methodology of the study, including a description of solar energy greenhouses; the energy of solar radiation; shading of the north roof; shading of the end ...
BackgroundWithin the last 25 years, after the introduction of the swimbladder nematode Anguillicoloides crassus from East-Asia to Europe, a body of work has aggregated...Full Text Available
BackgroundGastrointestinal stromal tumors (GISTs) are mesenchymal tumors that develop in the wall of the gastrointestinal tract and their diagnosis during pregnancy or puerperium...Full Text Available
We report a case of 38-year-old male, who presented with a large pulsatile swelling on the left side of the anterior chest wall of 4 months’ duration with a gradual increase in size. He gave...Full Text Available
Unless relaxation of the stringent response is achieved, all nongrowing bacteria rapidly develop resistance to autolysis induced by a variety of agents, including all classes of cell wall synthesis...Full Text Available
In the body, vascular cells continuously interact with tissues that possess nanostructured surface features due to the presence of proteins (such as collagen and elastin) embedded in the vascular wall....Full Text Available
Symplastic transport occurs between neighbouring plant cells through functionally and structurally dynamic channels called plasmodesmata (PD). Relatively little is known about the composition of PD or the mechanisms that facilitate molecular transport into neighbouring cells. While transmission electron microscopy (TEM) provides 2-dimensional information about the structural components of PD, 3-dimensional information is difficult to extract from ultrathin sections. This study has exploited high-resolution scanning electron microscopy (HRSEM) to reveal the 3-dimensional morphology of PD in the cell walls of algae, ferns and higher plants. Varied patterns of PD were observed in the walls, ranging from uniformly distributed individual PD to discrete clusters. Occasionally the thick walls of the giant alga Chara were fractured, revealing the surface morphology of PD within. External structures such as spokes, spirals and mesh ...
A compact heat exchanger pedestal array for augmenting heat transfer in a machine is disclosed. The compact heat exchanger pedestal array includes a wall having first and second surfaces. The first surface faces a heated flow path and the second surface p...
An experimental investigation of heat transfer characteristics for various configurations of air jets impinging on the leading edge inner surface of a gas turbine blade wall is presented. Three configurations were investigated, namely a slot jet, a round ...
Moenomycin A (MmA) belongs to a family of natural products that inhibit peptidoglycan biosynthesis by binding to the peptidoglycan glycosyltransferases (PGTs), the enzymes that make the glycan...Full Text Available
This paper deals with electron flux densities and electron energy flux densities in positive column discharges. Recent kinetic calculations by Uhrlandt and Winkler have revealed the interesting physical phenomenon of radially inward directed energy flux densities in positive column plasmas. We have used a self-consistent positive column model, based on an accurate and highly detailed Monte Carlo code, to study this effect in more depth. The results of this study show a rather complex physical picture of electron particle and energy flux densities. Electrons with low energies usually exhibit radially outward directed particle and energy flux densities. At energies above the threshold for electronic excitation particle and energy flux densities are usually inward directed. Only close to the wall, at total energies above the wall potential energy, do these flux densities point towards the wall. The thickness of this ...
The objective of this study was to develop a specific immunological diagnostic assay for yellow disease in hyacinths, using monoclonal antibodies (MAbs). Mice were immunized with a crude cell wall preparation...Full Text Available
The curvature elastic modulus (bending stiffness) of stearoyloleoyl phosphatidylcholine (SOPC) bilayer membrane is determined from membrane tether formation experiments. R. E. Waugh and R. M. Hochmuth...Full Text Available
The dental pulp consists of loose connective tissue encased in rigid dentinal walls. Because of its topography the tissue has low interstitial compliance and limited capacity to expand during fluid...Full Text Available
In a previous study we found that nanofibrous poly(l-lactic acid) (PLLA) scaffolds mimicking collagen fibers in size were superior to solid-walled scaffolds in promoting osteoblast differentiation...Full Text Available
BackgroundWide resection with tumor-free margins is necessary in soft-tissue sarcomas to minimize local recurrence and to contribute to long-term survival. Information about treatment...Full Text Available
We used tryptophan auxotrophs of the dicot Arabidopsis thaliana (wall cress) to determine whether tryptophan has the capacity to serve as a precursor to the auxin, indole-3-acetic acid (IAA). Quantitative...Full Text Available
Cyclothiazomycin B1 (CTB1) is an antifungal cyclic thiopeptide isolated from the culture broth of Streptomyces sp. HA 125-40. CTB1 inhibited the growth of several filamentous fungi including plant pathogens along with swelling of hyphae and spores. The antifungal activity of CTB1 was weakened by hyperosmotic conditions, and hyphae treated with CTB1 burst under hypoosmotic conditions, indicating increased cell wall fragility. CTB1-sensitive fungal species contain high levels of cell wall chitin and/or chitosan. Unlike nikkomycin Z, a competitive inhibitor of chitin synthase (CHS), CTB1 did not inhibit CHS activity. Although CTB1 inhibited CHS biosynthesis, the same result was also obtained with a non-specific proteins inhibitor, cycloheximide, which did not reduce cell wall rigidity. These ...
BackgroundBlue nevi that arise from the Müllerian tract are rare melanocytic lesions. Several histopathologic variants of cellular blue nevi have been described. The angiomatoid...Full Text Available
The incidence of arrhythmias after acute myocardial infarction of the inferior wall varies with the affected segment and increases when there is right ventricular involvement. This paper provides a...Full Text Available
Using an expanded nuclear data base, the activation of nitrogen, aluminum, iron, nickel, copper, zirconium, niobium, molybdenum, tungsten, and lead were calculated for the first wall positions of the STARFIRE and MARS conceptual fusion reactors.
Hollow needles made of an electrically conducting material are attached by hinges in the openings of the perforated end of an insert in order to intensify heat and mass transfer. The free sections of the needles are placed outside the insert, and a wick is placed on the wall of the frame in the condensation area. The wick overlaps the inlet openings of the insert.
Mar 1, 2011 ... The most interesting flow characteristics observed were the occasional appearance of steady, ... pressure gradient, rather than wall divergence angle, controlled flow separation. ... Report/Patent Number: AGARD-AG-19/P9 ...
A safety analysis code to design a pressurized water reactor and to obtain the licenses including entire proprietary rights is under development in domestic R and D project. The tasks of KAERI is to develop the constitutive relations including models for defining flow regimes and flow regime related models for inter-phase friction, wall frictions, wall heat transfer, and interphase heat and mass transfer in the two-phase three-field equations. In this paper, the process will be presented for choosing the best flow regime maps which occur in gas-liquid two-phase flow in horizontal and vertical tubes.
A safety analysis code to design a pressurized water reactor and to obtain the licenses including entire proprietary rights is under development in domestic R and D project. The tasks of KAERI is to develop the constitutive relations including models for defining flow regimes and flow regime related models for inter-phase friction, wall frictions, wall heat transfer, and interphase heat and mass transfer in the two-phase three-field equations. In this paper, the process will be presented for choosing the best flow regime maps which occur in gas-liquid two-phase flow in horizontal and vertical tubes.
Charged particle beams in circular accelerators couple with their surroundings through induced electromagnetic fields. This interaction can be described by so-called coupling impedances. In the frequency domain the impedance in connection with the bunch spectrum allows for stability analysis and estimates. However, for simulation codes one usually needs the wakefunction, the equivalent of the impedance in time domain. Recently the transverse impedance of a cylindrical pipe with arbitrary surface impedance was given by L. Vos. An expression for the wakefunction of this transverse resistive wall impedance with inductive bypass is derived here.
A simple formulation is presented for torsion analysis of hollow tubes with polygonal shapes. Thicknesses of segments of cross section can be different. Governing equations in term of Prandtl's stress function are used to derive the formulas. The derived formulas are so simple that computations can be carried out with a pocket calculator. Several examples are presented to show the accuracy and efficiency of the formulation. The obtained results are verified by accurate finite element solutions. It will be seen that the derived formulas can be useful for analysis of thin-walled and moderately thick-walled hollow tubes.
Natural convection of vaporizing Deuterium at 25 K transports the heat generated in the moderator cell of the cold neutron source to a He cooled condenser. The thermohydraulics of this thermosiphon were precalculated and the results verified by experiments in a 1:1 model using D_2 as fluid. The experimental results show that the thermosiphon operates stable. The demanded liquid content of the cell as well as wall temperatures below 50 K can be ensured by a proper design of the cell outlet flow geometry. A 7 min. loss of cryogenic power results in transient temperatures of the cell wall of not more than 300 K.
Various remedial measures have been tried to lower radon levels in buildings in Uranium City. The methods used are source material removal, passive ventilation of crawl spaces, sub-floor ventilation, complete epoxy coating of the entire basement, sealants for floor-wall joints and cracks in basements, electrostatic precipitators, mechanical ventilation, and sealing and grouting concrete block plenums in basement walls. The type and condition of structures encountered in Uranium City as well as the relative isolation of the town indicate that mechanical ventilation is the most long-term cost-effective method.
Twenty-seven patients with symptoms or clinical findings suggesting joint or bone disorders of the anterior chest wall (ACW) were evaluated by spiral CT with 3-dimensional (3-D) and multiplanar reconstructions. Preceding conventional ACW tomography was performed in 10 patients. ACW joint and bone changes were visualized more adequately by coronal 2-D reconstructions based on spiral CT than by conventional tomography. In addition, nonossified costal cartilages and soft tissue lesions were demonstrated. 3-D reconstructions sometimes added information, especially in patients with fracture and dislocation. (orig.).
A solar energy receiver is described including a separable endless wall formed of a ceramic material having defined therein a cavity of a substantially cylindrical configuration for entrapping solar flux, and an acceptance aperture adapted to admit to the cavity a concentrated beam of solar energy, said wall being characterized by at least a pair of contiguously related segments separated by lines of cleavage intercepting said aperture, at least one of the segments being supported for pivotal displacement, and a thermal responsive actuator adapted to respond to excessive temperatures within the cavity for initiating pivotal displacement of said one segment, whereby thermal flux is permitted to escape from the cavity.
A flow field and particle trajectory in a HDD (Hard Disk Drive) between two rotating disks in axisymmetric enclosures is investigated using CFD code FLUENT/UNS. The RNG k-{epsilon} model is used as a turbulent model. In this study, the flow field between two disks are symmetric, and the flow field near the enclosure is very complex. Cross stream vectors are shown both for blowing and no blowing from the hub. The larger a particle, the more fast the particle deposits at the walls. In the case of blowing from the hub, the more fast the particle deposits at the walls. (author). 9 refs., 12 figs., 1 tab.
The biodegradation of ring-/sup 14/C- and methyl-/sup 14/C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO/sub 2/. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.
The biodegradation of ring-"1"4C- and methyl-"1"4C-labeled paraquat by the soil yeast Lipomyces starkeyi was studied in vitro. It was found that the degradation of paraquat (acting as a sole source of culture nitrogen) resulted in the accumulation in the extracellular medium of radiolabeled acetic acid. The culture also evolved radiolabeled CO_2. The results suggest that the degradation of paraquat by L. starkeyi is associated with the integrity of the cell wall and that disruption or removal of the wall results in a complete loss of degradative capability. A mechanism for the degradation of paraquat by this organism is postulated.
A method and apparatus for operating a compression ignition engine having a cylinder wall, a piston, and a head defining a combustion chamber. The method and apparatus includes delivering fuel substantially uniformly into the combustion chamber, the fuel being dispersed throughout the combustion chamber and spaced from the cylinder wall, delivering an oxidant into the combustion chamber sufficient to support combustion at a first predetermined combustion duration, and delivering a diluent into the combustion chamber sufficient to change the first predetermined combustion duration to a second predetermined combustion duration different from the first predetermined combustion duration.
This reports is a literature survey on models and correlations for determining flow pattern that are used to simulate thermal-hydraulics in nuclear reactors. Determination of flow patterns are a basis for obtaining physical values of wall/interfacial friction, wall/interfacial heat transfer, and droplet entrainment/de-entrainment. Not only existing system codes, such as RELAP5-3D, TRAC-M, MARS, TRACE, CATHARE) but also up-to-date researches were reviewed to find models and correlations
Numerical solutions for fully developed laminar flow in internally finned tubes with trapezoidal and triangular fin profiles were given with Finite Element Method (FEM): The heat transfer characteristics were obtained and compared under the boundary conditions of uniform heat flux, uniform wall temperature, and the third boundary condition with finite wall thermal conductivity considered. The numerical results show that boundary conditions have pronounced effects on the temperature field. Furthermore, a new mechanism on the heat transfer augmentation of internally finned tubes is proposed.
Analytical solutions are derived for a flow in a semi-infinite vertical porous medium with heat and mass transfer. When the temperature and mass concentration are uniform a constant pressure is possible and sustains a fully developed flow. Thereafter there is a small perturbation on the wall temperature and concentration and the subsequent two-dimensional problem is tackled for a large Prandtl number, free convection parameters and small Reynolds number. The heat transfer rate at the wall is discussed quantitatively. (author). 4 refs.
A safety analysis code, named as SPACE, for a pressurized water reactor is under development to obtain a licensing to be used for the PWR design and to hold entire proprietary rights. The task of KAERI is to develop the physical models and correlations which are required to solve the field equations. It can be divided into four parts; i) flow regime determination, ii) wall heat transfer, iii) wall and interfacial friction, iv) interfacial heat and mass transfer. This paper will describe the process to develop the models for the two-phase flow regime maps in the horizontal and vertical pipes.
A safety analysis code, named as SPACE, for a pressurized water reactor is under development to obtain a licensing to be used for the PWR design and to hold entire proprietary rights. The task of KAERI is to develop the physical models and correlations which are required to solve the field equations. It can be divided into four parts; i) flow regime determination, ii) wall heat transfer, iii) wall and interfacial friction, iv) interfacial heat and mass transfer. This paper will describe the process to develop the models for the two-phase flow regime maps in the horizontal and vertical pipes.
In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.
In this paper the diffusion of tritiated water vapor into concrete walls is studied to evaluate tritiated water retention capacity of a fusion reactor concrete building. Using a model of the tritiated water diffusion determined form experimental results, depth profiles of tritiated water in concrete are calculated in the case of being exposed to air containing tritiated water vapor during the normal operational condition of a fusion reactor. A 0.5-m-thick concrete is sufficient for reactor hall walls from a viewpoint of the tritium containment.
The magnetoresistance in an FeNi submicron-structure comprising two wires of 80 and 200 nm in width connected in series was measured at 77 K. When the external magnetic field was applied parallel to the wire axis, two switching fields corresponding to the distinct coercive force of the two wires were observed. When the external magnetic field was applied at an angle of {theta}>30 deg. to the wire axis one switching field was observed, indicating simultaneous magnetization reversal in both wires. This indicates that the domain-wall trapping around the joint can be controlled systematically in terms of the direction of the external magnetic field.
Alpha particle confinement is necessary for ignition of a D-T tokamak fusion plasma and for first wall protection. Due to high radiation backgrounds and temperatures, scintillators and semiconductor detectors may not be used to study alpha particles which are lost to the first wall during the D-T programs on JET and ITER. An alternative method of charged particle spectrometry capable of operation in these harsh environments, is proposed: it consists of thin foils of electrically isolated conductors with the flux of alpha particles determined by the positive current flowing from the foils. 2 refs., 3 figs.
The development of new electro-optical instrumentation for studying the annular dispersed two-phase flow regime is described. The system measures the thickness of the water film and droplet size and velocity distributions which would be encountered in such a flow regime. The water film thickness is measured by an improved capacitance method with a short time constant using newly developed sensor electrodes. The electrodes are made flush with the inner wall of a cylindrical tube and do not disturb the flow. In the test equipment, steady, laminar flow of water along the inner wall of the tube is controlled by appropriate valves and a porous jacket while droplets are introduced by means of a special spray nozzle.
An anaerobic fermenter-decanter for the purification of residual water from the sugar industry, with recovery of methane, consists of a tank with inclined walls, with a central agitator on a vertical shaft. A flexible cover anchored by its periphery to the walls of the tank and totally submerged forms a collecting pocket for the fermentation gases. The water to be purified is introduced, after being heated to about 35, towards the bottom of the tank near the agitator. A metal collecting bell with submerged edges and with the shaft of the agitator passing axially through it is connected by its edges to a central opening of the cover. The purification yields may exceed 90%.
A borehole televiewer (BHTV) logging was conducted to investigate cracks in bored wells. The logging process shoots ultrasonic waves onto bore walls and utilizes reflection waves from the bore walls. If the bores are filled with muddy water, or the ultrasonic waves can pass through even if vinyl chloride tubes have been inserted after excavation, the state of the bore walls can be investigated in principle. Conventional optical scanners are, however, incapable of making this investigation. The BHTV logging can be used for identifying lithofacies from reflection intensities from bore walls (it depends on sound impedance of rocks), not to speak of finding cracks. As a result of making logging upon setting time windows from 105 to 145 {mu} sec in a bored well inserted with a vinyl chloride tube, cracks in the bore wall were identified clearly through the vinyl chloride tube. If the ...
The process operation of the hot wall vapor deposition method, formation of dry organic thin film and the control of molecular arrangement were described. This equipment included a substrate on the upper end of the hot wall tube and the vapor source at the lower end. The remarkable features are the hot wall tube which plays the role to hold vaporizing molecules to the high temperature and to transport molecules, and the flip flop mechanism which gives some idle period for the molecular vaporization by shutter closing. Several experiments were carried out by using stearic acid and by changing the distance S from the upper end of hot wall quartz tube to the substrate, the furnace temperature T{sub f} and the substrate temperature T{sub s}. When T{sub f} is equal to or less than the melting point of stearic acid, molectles are preferentialy made to vertical arrangement. In the case of T{sub f} more than ...
A magnetic measuring technique, which sorts out defects according to a distribution function n, was used to study the influence of electron irradiation on 50-50 NiFe. The distribution function is determined in terms of the maximum force f/subm/ that a defect can exert on a forward moving domain wall, or equivalently, the range z_0, which is the distance the mean position of the wall may move past the defect before the wall snaps free from the pinning action of the defect. The range and maximum force are related by a spring constant k, viz., f/subm/=kz_0. The quantity n (z_0) dz_0 gives the number of defects per unit volume having a range between z_0 and z_0+dz_0. Distribution functions were determined before and after electron irradiation. The irradiation was for 100 min with 18-MeV electrons with a dose of 1.1times10"1"7 e/cm"2. Following irradiation, there was a substantial decrease in the number of short-range defects ...
The aim of this study was to compare multidetector-row computed tomography (MDCT) findings between cases of sclerosing cholangitis with autoimmune pancreatitis (SC-AIP) and infiltrative extrahepatic cholangiocarcinoma (IEC). We retrospectively assessed MDCT findings from 16 IEC cases and 13 SC-AIP cases. MDCT findings were analyzed with regard to location, length, wall thickness, contour, stricture wall enhancement pattern, proximal duct diameter, and the presence of diffuse concentric thickening in the proximal duct and gallbladder wall thickness. Stricture length, stricture wall thickness, and proximal duct diameter were significantly smaller for SC-AIP than for IEC: 19.3#+-#8.7 vs. 31.8#+-#12.0 mm (P=0.004), 2.1#+-#1.3 vs. 4.1#+-#1.3 mm (P<0.001), and 9.2#+-#3.9 vs. 13.3#+-#5.0 mm (P=0.012), respectively. SC-AIP was correlated with stricture location in both the intrapancreatic and hilar hepatic ...
This study reports on the physical-chemical behaviour of swelling di-octahedral clays (smectites) and their interaction with aqueous solutions and bacteria (Shewanella putrefaciens). Experimental results are presented for compacted clays, hydrated under confined volume conditions, using a new type of reaction-cell (the 'wet-cell' of Warr and Hoffman, 2004) that was designed for in situ X-ray diffraction (XRD) measurement. For comparison, dispersed clay systems were studied using standard batch solutions subjected to varying degrees of agitation. The combination of time-dependent in situ XRD measurements with gravimetric measurements and calculated diffraction patterns using the CALCMIX software (Plancon and Drits, 1999) allowed to successful quantification of the dynamics of water uptake and storage. This analytical procedure combined with published water vapour adsorption data enabled determination of the abundance of structured water layers, developed in the ...
The design of the first structural wall (FSW) in an inertial confinement fusion (ICF) reactor requires some knowledge of the expected wall loading produced by x-ray and neutron deposition; specifically in the High Yield Lithium Injection Fusion Energy (HYLIFE) reactor, wall loading results from two sources -- gas shock and liquid impact. Gas shock is derived from x-ray deposition in the thin layers of exposed blanket material, producing ionized vapor, which will generate gas shock on the FSW. Liquid impact, on the other hand, results from the acceleration of liquid blanket material by two possible forces -- the drag from vapor expansion through the blanket material and the neutron-induced isochoric disassembly process. Both impacts, however, are coupled by the interaction of hot gas expanding through the liquid blanket. This paper discusses scaling methods for estimating pressure and impulse on the HYLIFE FSW from these ...
A system is described adapted for alternative use as a diverter or a blowout preventer for a bottom supported drilling rig and adapted for connection to a permanent housing attached to rig structural members beneath a drilling rig rotary table, the permanent housing having an outlet connectable to a rig fluid system flow line. The system consists of: a fluid flow controller having a controller housing with a lower cylindrical opening and an upper cylindrical opening and a vertical path therebetween and a first outlet passage and a second outlet passage provided in its wall, a packing element disposed within the controller housing, and annular piston means adapted for moving from a first position to a second position, whereby in the first position the piston means wall prevents interior fluid from communicating with the outlet passages in the controller housing wall and in the second position the piston means ...
Microbial volatile organic compounds (MVOCs) emitted from the mould species Penicillium expansum, P. chrysogenum, Aspergillus versicolor, A. fumigatus, A. niger and Cladosporium cladosporoides were analyzed by means of solid phase microextraction (SPME) and GCMS. The mould species were cultivated on the synthetic agar dichloran chloramphenicol (DG 18) and on wet wall paper. The production of MVOCs was monitored over several weeks to detect changes in the emission rates between the initial stage and later periods of growth. The cultivation on the synthetic agar resulted in MVOC patterns with a wide variety of signals. In contrast, the growth on wet wall paper led to changed MVOC patterns with less signals. The emission rates were drastically reduced. Components emitted by all six fungi species on wall paper were 2-pentanol and 2-pentanone. 1-Octen-3-ol was emitted by five fungi species. 2-Pentanol was only detected in ...
Small circular and noncircular channels are representative of flow passages in compact evaporators and condensers. This paper describes results of an experimental study on heat transfer to the flow boiling of refrigerant- 12 in a small circular tube of diameter = 2.46 mm. The objective of the study was to assess the effect of channel size on the heat transfer coefficient and to obtain additional insights relative to the heat transfer mechanisms. The flow channel was made of brass and had an overall length of 0.9 m. The channel wall was electrically heated, and temperatures were measured on the channel wall and in the bulk fluid stream. Voltage taps were located at the same axial locations as the stream thermocouples to allow testing over an exit quality range of 0.21 to 0.94 and a large range of mass flux (63 to 832 kg/m{sup 2}s) and heat flux (2.5 to 59 kW/m{sup 2}). Saturation pressure was nearly constant, averaging 0.82 MPa for most of the ...
Liquid sodium is used as coolant in Fast Breeder Reactors (FBR). There is a likelyhood of sodium spillage in ambient air in the Steam Generator Building (SGB) of the FBR plant. Due to high chemical reactivity with oxygen, especially at temperatures greater than 573 K, it catches fire very easily. In order to carryout safety related experimental studies for different modes of sodium fires and to develop suitable mathematical models for the assessment of their consequences, an experimental facility (SFEF, Sodium Fire Experimental Facility) is being setup a IGCAR, Kalpakkam. The SFEF is having a 540 m"3 volume experimental hall. Stainless steel linear will be provided on the inside surfaces of experimental hall walls, ceiling and floor. Analysis has been carried out for enclosed sodium pool fire scenarios in SFEF by using sodium pool fire code SOFIRE II, which estimates the thermal transients like pressure rise, gas temperature rise, cell wall ...
In this paper, a phenomenological model of the thermal hydraulics of convective boiling in the post-critical-heat-flux (post-CHF) regime is developed and discussed. The model was implemented in the TRAC-PF1/MOD2 computer code (an advanced best-estimate computer program written for the analysis of pressurized water reactor systems). The model was built around the determination of flow regimes downstream of the quench front. The regimes were determined from the flow-regime map suggested by Ishii and his coworkers. Heat transfer in the transition boiling region was formulated as a position-dependent model. The propagation of the CHF point was strongly dependent on the length of the transition boiling region. Wall-to-fluid film boiling heat transfer was considered to consist of two components: first, a wall-to-vapor convective heat-transfer portion and, second, a wall-to-liquid heat transfer representing ...
Nitrate microelectrodes and ORP microelectrodes were fabricated to study the denitrification characteristics of dynamic membrane at different COD loadings. The denitrification process was found at 0.6-1 mm depth beneath the interface of biofilm/bulk. The results of ORP microelectrode also demonstrated that the ORP value in the range of denitrification area was between 88.6 approximately -128.4 mV which was appropriate to denitrification. When the COD loading was 0.45 kg/(m3 x d), the denitrification rate (NO3- -N) was the maximum of 0.6347 x 10(-6 mol/(L x s). With the increase of COD loading, the denitrification area was increasing and two layers with different denitrification rates emerged in the dynamic membrane. The phenomenon implied the effect of organic concentration, oxygen concentration and bacterial competition on the denitrification rate. PMID:17117632
The study evaluates 160 cases of positive spermioculture taken from 522 sterile individuals examined by the authors at the Couple Sterility Outpatient unit in Department A of the Institute of Gynecology and Obstetrics at Turin University during the period between January 1984 and December 1993. The germs responsible for infection were assayed in order to evaluate the strains which showed the highest incidence every year. Whereas there was no significant change in the absolute number of cases of sterility over the period, the number of cases caused by infection increased significantly during the second five-year period. It was found that the germs predominantly implicated in the genesis of male sterility formed part of the so-called mixed flora group, responsible in women for syndromes of often asymptomatic bacterial vaginosis which are not identified and consequently not treated. PMID:8559444
Abstract Silver-impregnated wound dressings continue to be routinely used for the management of infected wounds, or wounds that are at risk of becoming infected. The ability of antimicrobials that have been incorporated into wound dressings to kill microorganisms within the dressing requires appropriate evaluation using in vitro models. In vitro models that have been exploited for this purpose have included the corrected zone of inhibition and the log reduction assay. However, these and other related culturable-based assays are purported to have poor correlation with the overall microbicidal barrier activity of an antimicrobial wound dressing. This is because culturable-based methods only retrospectively indicate bacterial cell death and do not take into account viable but nonculturable st...
The type III secretion system among Gram-negative bacteria is known to deliver effectors into host cell to interfere with host cellular processes. The type III secretion system in Yersina, Pseudomonas and Enterohemorrhagic Escherichia coli have been well documented to be involved in the bacterial pathogenicity. The existence of type III secretion system has been demonstrated in neuropathogenic E. coli K1 strains. Here, it is observed that the deletion mutant of type III secretion system in E. coli strain EC10 exhibited defects in the invasion and intracellular survival in Acanthamoeba castellanii (a keratitis isolate) compared to its parent strain. Next, it was determined whether type III secretion system plays a role in E. coli K1 survival inside Acanthamoeba during the encystment process...
In this work, the antibacterial effect of fluoroquinolones (FQs) upon Escherichia coli (E.coli) was measured with and without application of 40kHz ultrasound (US) stimulation. The research results demonstrated that simultaneous application of 40kHz US apparently enhanced the antibacterial effectiveness of FQs. That is, the synergistic effect was observed and the bacterial viability was reduced when FQs and US were combined. In addition, various influencing factors, such as FQs drug concentration, US irradiation time and solution temperature, on the inhibition of E.coli were also investigated. The antibacterial activity was enhanced apparently with increasing of FQs drug concentration, US irradiation time and solution temperature. Furthermore, we discussed preliminarily the mechanism of US ...
Abstract. The potential effects of synthetic unmethylated oligodeoxynucleotides (ODN) containing CpG motifs, mimicking bacterial DNA, has never been evaluated on the immune response in the teleost fish gilthead seabream (Sparus aurata), the most important fish species in Mediterranean aquaculture. First, binding and competition studies have demonstrated that binding is saturated and promiscuous, suggesting the participation of several receptors. Moreover, leucocyte cytotoxic (NCC) activity, production of ROIs (reactive oxygen intermediates), and expression of immune-relevant genes was greatly primed by ODNs. Focusing on the mechanism, the TLR9 gene is widely distributed in seabream tissues and differently regulated in vitro by several stimuli. Moreover, and for the first time in fish, TLR9...
Some acylhydrazine derived ONO donor Schiff bases and their Co(II) and Ni(II) complexes have been prepared having the same metal ion (cation) but different anions. These synthesized metal(II) complexes have been characterized on the basis of their elemental analyses, magnetic moment, molar conductance, and IR and electronic spectral data. All of the Schiff base ligands function as tridentates and the deprotonated enolic form is preferred for coordination. In order to evaluate the effect of anions on the bactericidal activity, these synthesized complexes, in comparison to the uncomplexed Schiff bases have been screened against bacterial species., Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and the results are reported. PMID:18475936
The Na+-driven bacterial flagellar motor is a molecular machine powered by an electrochemical potential gradient of sodium ions across the cytoplasmic membrane. The marine bacterium Vibrio alginolyticus has a single polar flagellum that enables it to swim in liquid. The flagellar motor contains a basal body and a stator complexes, which are composed of several proteins. PomA, PomB, MotX, and MotY are thought to be essential components of the stator that are required to generate the torque of the rotation. Several mutations have been investigated to understand the characteristics and function of the ion channel in the stator and the mechanism of its assembly around the rotor to complete the motor. In this review, we summarize recent results of the Na+-driven motor in the polar flagellum of ...
The use of indigenous bacterial root endophytes with biocontrol activity against soil-borne phytopathogens is an environmentally-friendly and ecologically-efficient action within an integrated disease management framework. The earliest steps of olive root colonization by Pseudomonas fluorescens PICF7 and Pseudomonas putida PICP2, effective biocontrol agents (BCAs) against Verticillium wilt of olive (Olea europaea L.) caused by the fungus Verticillium dahliae Kleb., are here described. A gnotobiotic study system using in vitro propagated olive plants, differential fluorescent-protein tagging of bacteria, and confocal laser scanning microscopy analysis have been successfully used to examine olive roots?Pseudomonas spp. interactions at the single-cell level. In vivo simultaneous visualization...
The ability of the R46 R factor and its derivative pKM101 to modify sensitivity to "6"0Co #gamma# radiation was studied. In Escherichia coli K12 both plasmids enhanced bacterial survival after "6"0Co #gamma# irradiation. This effect was dependent on recA"+ genotype but not on recB"+, recB"+recC"+, and recF"+ genotypes. 5-Fluorouracil eliminated the R46 R factor from the parent and its rec"- mutant strains. These strains lost not only the antibiotic resistance coded for R46 R factor but their radioresistance as well.
The world of antibiotic drug discovery and development is driven by the necessity to overcome antibiotic resistance in common Gram-positive and Gram-negative pathogens. However, the lack of Gram-negative activity among both recently approved antibiotics and compounds in the developmental pipeline is a general trend despite the fact that the plethora of covered drug targets are well-conserved across the bacterial kingdom. Such intrinsic resistance in Gram-negative bacteria is largely attributed to the activity of multidrug resistance (MDR) efflux pumps. Moreover, these pumps also play a significant role in acquired clinical resistance. Together, these considerations make efflux pumps attractive targets for inhibition in that the resultant efflux pump inhibitor (EPI)/antibiotic combination d...
Selected applications of novel techniques in Agricultural Biotechnology, Health Food formulations and Medical Biotechnology are being reviewed with the aim of unraveling future developments and policy changes that are likely to open new markets for Biotechnology and prevent the shrinking or closing of existing ones. Amongst the selected novel techniques with applications in both Agricultural and Medical Biotechnology are: immobilized bacterial cells and enzymes, microencapsulation and liposome production, genetic manipulation of microorganisms, development of novel vaccines from plants, epigenomics of mammalian cells and organisms, and biocomputational tools for molecular modeling related to disease and Bioinformatics. Both fundamental and applied aspects of the emerging new techniques are being discussed in relation to their anticipated, marked impact on future markets and present policy changes that are needed for success in either Agricultural or Medical ...
Toxigenic Clostridium sordellii strains are increasingly recognized to cause highly lethal infections in humans that are typified by a toxic shock syndrome (TSS). Two glucosylating toxins, lethal toxin (TcsL) and hemorrhagic toxin (TcsH) are believed to be important in the pathogenesis of TSS. While non-toxigenic strains of C. sordellii demonstrate reduced cytotoxicity in vitro and lower virulence in animal models of infection, there are few data regarding their behavior in humans. Here we report a non-TSS C. sordellii infection in the context of a polymicrobial bacterial cholangitis. The C. sordellii strain associated with this infection did not carry either the TcsL-encoding tcsL gene or the tcsH gene for TcsH. In addition, the strain was neither cytotoxic in vitro nor lethal in a murine...
We describe the analysis of forward mutations induced in the tetracycline resistance gene of the plasmid pBR322 by directing the reaction of the carcinogen N-acetoxy-N-2-acetylaminofluorene (N-AcO-AAF) to a small restriction fragment (BamHI, SalI) that is located in the proximal part of the antibiotic-resistance gene. Mutant plasmids obtained both in wild type and excision repair deficient (uvrA) bacterial cells are compared. Preliminary data showing the distribution of the -AAF adducts along this restriction fragments are discussed in relation to the observed spectrum of mutations. 20 references, 4 figures.
Complex I (NADH:ubiquinone oxidoreductase) is the largest enzyme of the mitochondrial respiratory chain. Compared to its bacterial counterpart which encompasses 14-17 subunits, mitochondrial complex I has almost tripled its subunit composition during evolution of eukaryotes, by recruitment of so-called accessory subunits, part of them being specific to distinct evolutionary lineages. The increasing availability of numerous broadly sampled eukaryotic genomes now enables the reconstruction of the evolutionary history of this large protein complex. Here, a combination of profile-based sequence comparisons and basic structural properties analyses at the protein level enabled to pinpoint homology relationships between complex I subunits from fungi, mammals or green plants, previously identified...
Abstract Development of inhibitors and vaccines that mitigate rumen-derived methane by targeting methanogens relies on knowledge of the methanogens present. We investigated the composition of archaeal communities in the rumens of farmed sheep (Ovis aries), cattle (Bos taurus) and red deer (Cervus elaphus) using denaturing gradient gel electrophoresis (DGGE) to generate fingerprints of archaeal 16S rRNA genes. The total archaeal communities were relatively constant across species and diets, and were less variable and less diverse than bacterial communities. There were diet- and ruminant-species-based differences in archaeal community structure, but the same dominant archaea were present in all rumens. These were members of three coherent clades: species related to Methanobrevibacter ruminan...
Greenman J, Thorn RMS, Saad S, Austin AJ. In vitro diffusion bed, 3-day repeat challenge `capacity' test for antimicrobial wound dressings. Int Wound J 2006;3:322-329. Abstract The aim of this study was to develop an in vitro wound infection model that allows the comparison of the bacterial kill rate of antimicrobial wound dressings over the course of 3 days, with renewed microbial challenges each day, under realistic wound-like conditions. A test bed model of a moderately exuding wound was constructed from a hydrogel containing releasable foetal calf serum (FCS), and cellulose discs dosed with test microbes (Methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa) suspended in 50% FCS applied at the interface between the test dressing and the hydrogel test bed. Freshly prep...
Abstract Alkali tolerance and the mechanism of microcystin (MC) degradation were investigated in the MC-degrading bacterial species, Sphingopyxis sp. C-1, to better understand the increased MC degradation under the alkaline conditions that arise during the disappearance of water blooms. MC-degrading bacteria harbour mlrA, mlrB and mlrC that encode MC-degrading enzymes. Sphingopyxis sp. C-1 also possesses these genes, as well as the mlrD gene that has been assumed to encode MC and its degradation transporter. This study demonstrated that MC degradation activity was promoted by the intermittent addition of microcystin-LR (MCLR) to cultures of strain C-1. That the expression of mlrA, mlrB and mlrC is induced by MCLR also was indicated, whereas that of mlrA and mlrB is induced by the MCLR degr...
In tomato crop, the induction of resistance emerges as an important alternative for achieving the reduction of chemicals in disease control. This study aimed to evaluate the ability of 28 Trichoderma isolates to promote the growth of tomato seedlings and to induce systemic resistance (ISR) against Xanthomonas euvesicatoria and Alternaria solani, the causal agents of bacterial spot and early blight, respectively. Twelve isolates promoted the increase of plant dry matter mass (DMM) above 100%, showing the great potential of these strains. All isolates were able to colonize the root system of tomato plants. The plant growth-promoting isolates were further evaluated for potential elicitation of ISR. Treatment of the soil with all Trichoderma isolates provided protection in tomato plants from 2...
Abstract To investigate the link between the functionality and the diversity of microbial communities under strong selective pressure from pollutants, two types of mesocosms that simulate natural attenuation and phytoremediation were generated using soil from a site highly contaminated with jet fuel and under air-sparging treatment. An increase in the petroleum hydrocarbon concentration from 4900 to 18-500-mg-kg-1-dw soil simulated a pollutant rebound (postremediation pollutant reversal due to residual contamination). Analysis of soil bacterial communities by denaturing gradient gel electrophoresis of PCR-amplified 16S rRNA gene fragments showed stronger changes and selection for a phylogenetically diverse microbial population in the mesocosms with pollutant-tolerant willow trees. Enumerat...
Delayed endolymphatic hydrops (DEH) is a unique disorder characterized by fluctuating otologic symptoms in the setting of preexisting unilateral deafness. The symptoms include aural fullness, fluctuating hearing, and/or episodes of vertigo similar to those observed in Meniere disease and may occur ipsilateral or contralateral to the previously deafened ear. In most reported cases, the unilateral deafness has been a profound sensorineural hearing loss with a sudden onset that has been variously attributed to bacterial or viral labyrinthitis, acoustic or cranial trauma, otosclerosis, and congenital CMV infection. Familial occurrence of the syndrome has not previously been reported in the literature. In this report, we describe two possible familial instances of delayed DEH. These patients ra...
We describe a simple one-pot thermal decomposition method for the production of a stable colloidal suspension of narrowly dispersed superparamagnetic Fe3O4-Ag core-shell nanostructures. These biocompatible nanostructures are highly toxic to microorganisms. Antimicrobial activity studies were carried out on both Gram negative (Escherichia coli and Proteus vulgaris) and Gram positive (Bacillus megaterium and Staphylococcus aureus) bacterial strains. Efforts have been made to understand the underlying molecular mechanism of such antibacterial actions. The effect of the core-shell nanostructures on Gram negative strains was found to be better than that observed for silver nanoparticles. The minimum inhibitory concentration (MIC) values of these nanostructures were found to be considerably lowe...
The primary charge separation in photosynthetic bacteria generates a dimeric bacteriochlorophyll (BChl) cation and a bacteriopheophytin (BPheo) anion which lie within close proximity of each other (approx. 10 A). The two radicals also lie within van der Waals contact on opposite sides of a lone BChl bridging molecule. Spectral changes in the red (Q/sub y/) band of the bridge BChls have been observed on picosecond time scales following excitation of the reaction center (RC) and have been variously attributed to the formation of a BChl anion, to a charge-transfer state, or to electrochromic effects. They present calculations here which suggest that electrochromic effects caused by the photogenerated cation and/or anion can rationalize the optical changes observed in the flash photolyses as well as in trapping experiments.
Using carbon-paste-CuFeS{sub 2} electrodes and a cyclic voltammetric technique, it was found that a large number of intermediate electrochemical oxidation reactions were associated with the dissolution of chalcopyrite in presence and absence of bacteria. The effects of concentrations of copper, ferrous and ferric ions, as well as of agitation on the peaks of cyclic voltammograms were measured. It was established that chalcopyrite oxidation was solid-state controlled as suggested by the data of chronopotentiometric and chronoamperometric measurements. The activation energy of solid state diffusion of chalcopyrite leaching was determined by the Sand's method to be {triangle}E{sub a} = 20.5 kJ. The leaching mechanism is discussed in terms of solid-state properties (energy bonding) of the n-type semiconductor chalcopyrite and energy density states of redox systems of acidic bacterial leach media. A generalized model for the mechanism of chalcopyrite leaching ...
Ethnopharmacological relevance: Extracts of the roots of Scutellaria baicalensis Georgi (Labiatae) have been widely used to relieve fever related to bacterial infection and inflammatory diseases in traditional Korean medicine and have been reported to be effective in brain diseases. These experiments were conducted to examine the effects of oral administration of Scutellaria baicalensis extracts on the rescue of memory impairments induced by chronic cerebral hypoperfusion or chronic lipopolysaccharide (LPS) infusion. In addition, the underlying mechanisms of these effects were investigated. Materials and methods: In the first experiment, chronic cerebral hypoperfusion was induced in male Wister rats by bilateral common carotid artery occlusion (BCCAo). Daily administration of Scutellaria b...
Methane and carbon dioxide are the two main constituents of biogas. Biogas also contains traces of nitrogen, hydrogen, oxygen and hydrogen sulphide. When diesel engine runs on biogas, the combustion is poor as compared to diesel fuel. One of the reasons of poor combustion is the presence of carbon dioxide in the biogas. Percentage of methane and carbon dioxide in biogas varies with maturities of feed stock, temperature, water content, loading rate of raw material and bacterial actions. This paper examines the effect of variations of carbon dioxide in biogas on the performance of the engine to simulate the performance of the engine running with biogas from different sources (varying proportion of methane and carbon dioxide). (Author)
Several old and new observations suggest the existence in Crohn's disease of a phagocytic disorder of macrophages related to impaired bactericidal activity of host cells or to the presence of invasive bacteria that have developed strategies to counteract macrophage killing. It was recently reported that disordered macrophage cytokine secretion underlies impaired acute inflammation and bacterial clearance in Crohn's disease. Secretion of proinflammatory cytokines by CD macrophages was impaired in response to E. coli or specific Toll-like receptor agonists. In addition, major advances in the etiology of Crohn's disease came from the existence of polymorphism in NOD2 and autophagy-related susceptibility genes (ATG16L1 and IRGM) in patients and from the identification of the presence of adhere...
Acidification is one of the most common and serious problems inducing process failure in anaerobic digesters. The production of volatile fatty acids (VFAs) mainly triggers acidic shock. However, little is known about the bacteria involved in the processes of acidogenic metabolism, such as fermentation and reductive acetogenesis. Here, the metabolic responses of a methanogenic community to the acidification and resulting process deterioration were investigated using transcriptional profiling of both the 16S rRNA and formyltetrahydrofolate synthetase (FTHFS) genes. The 16S rRNA-based analyses demonstrated that the dynamic shift of bacterial populations was closely correlated with reactor performance, especially with VFA accumulation levels. The pH drop accompanied by an increase in VFAs stim...
2,6-Diacetyl pyridine based ligand was synthesized by the reaction of 2,6-diacetyl pyridine with thiocarbohydrazide in presence of acetic acid. The coordination compounds with Cr(III) and Ni(II) metal ions having [Cr(L)X]X2 and [Ni(L)X]X compositions (where L=ligand and X=NO3^-, Cl^- and CH3COO^-) were synthesized and characterized by physicochemical and spectral studies. The studies like elemental analyses, molar conductance measurements, magnetic susceptibility measurements, IR, UV-Vis, NMR, mass and EPR reveal that the complexes are octahedral. The compounds were examined against the pathogenic fungal and bacterial strains like Alternaria brassicae, Aspergillus niger, Fusarium oxysporum, Xanthomonas compestris and Pseudomonas aeruginosa. A. niger causes the diseases Apergillosis and Oto...
Thirty bacterial isolates were obtained from different sources and sites at Jeddah, Saudi Arabia, on chitin agar medium; 9 of the 30 isolates were cultured in liquid medium containing chitin as sole carbon and nitrogen sources. Isolate SM21, which was isolated from shrimp shells, showed the best growth and chitinase production in liquid medium. According to its morphological, physiological and biochemical characteristics, SM21 belongs to the genus Streptomyces and was identified as Streptomyces anulatus SM21. Identification was confirmed using 16S rDNA analysis. The chitinase enzyme was precipitated with 80% NH4SO4 and purified using DEAE-cellulose ion exchange chromatography followed by Sephadex G-100 gel filtration. The molecular weight determined using sodium dodecyl sulfate polyacrylam...
To the best of our knowledge, this is the first report on the chemical and microbial properties of traditional Iranian fish sauce, mahyaveh. Fish sauce samples used in this study originated from five different locations in the Southern part of Iran. The pH of mahyaveh samples from different locations was in the range of 4.89-7.55 and NaCl concentration was in the range of 7.48-17.1%. The overall mean of TVB-N in all the samples tested was 3098 mg/kg. Histamine, with the overall mean of 2662 mg/kg, was found to be the main biogenic amine in the Iranian fish sauce. The high histamine content can be related to the high levels of bacterial count especially enterobacteriaceae (overall mean of 3.41 log cfu/g) and lactic acid bacteria (overall mean of 4.13 log cfu/g) in this product. Spermidine w...
Human impacts such as eutrophication, overexploitation and climate change currently threaten future global food and drinking water supplies. Consequently, it is important that we understand how anthropogenic resource (bottom-up) and consumer (top-down) manipulations affect aquatic food web structure and production. Future climate changes are predicted to increase the inputs of terrestrial dissolved organic carbon to lakes. These carbon subsidies can either increase or decrease total basal production in aquatic food webs, depending on bacterial competition with phytoplankton for nutrients. This study examines the effects of carbon subsidies (bottom-up) on a pelagic community exposed to different levels of top-down predation. We conducted a large scale mesocosm experiment in an oligotrophic ...
ABSTRACT To date the effect of silver-containing wound dressings on biofilms, known to be present in chronic wounds, has not been determined or documented. In this current study, we aimed to determine the antimicrobial effect of a silver-containing dressing on biofilms grown in a chambered slide model. Before the addition of a wound dressing onto a 24-hour biofilm, composed of either Pseudomonas aeruginosa, Enterobacter cloacae, Staphylococcus aureus, or a mixed bacterial community, a fluorescent dye was applied. This enabled the viability of sessile bacteria to be monitored in real-time, using a rapid form of confocal laser scanning microscopy over a contact time period of 48 hours. By analyzing all the three-dimensional data generated from the confocal time-lapse sequences, 90% of all se...
A urine leukocyte count of > or = 50/mm3 together with a bacterial count of > or = 10(5) colony-forming units (CFUs) per milliliter was used to define significant infection in 160 children with neurogenic bladder and evaluate the leukocyte and nitrite components of the Chemstrip 9 test. A Chemstrip 9 leukocyte reading of or = 500 leukocytes together with a positive nitrite reaction occurred in 18 children and had a sensitivity of 40% with a 100% positive predictive value for infection. Other combinations of Chemstrip 9 leukocyte and nitrite reactions were unhelpful or of uncertain value. Selection of up to three specimens from each patient increased the number of samples to 360 and provided general confirmation of the above conclusions. Nitrofurantoin may reduce the sensitivity of the nitrite strip reaction. PMID:8359003
Abstract:- Campylobacter jejuni-is the leading cause of bacterial diarrheal illness worldwide. Many strains are now becoming multidrug resistant. Apple-based edible films containing carvacrol and cinnamaldehyde were evaluated for bactericidal activity against antibiotic resistant and susceptible-C. jejuni-strains on chicken. Retail chicken breast samples inoculated with D28a and H2a (resistant strains) and A24a (a sensitive strain) were wrapped in apple films containing cinnamaldehyde or carvacrol at 0.5%, 1.5%, and 3% concentrations, and then incubated at 4 or 23 C for 72 h. Immediately after wrapping and at 72 h, samples were plated for enumeration of viable-C. jejuni. The antimicrobial films exhibited dose- and temperature-dependent bactericidal activity against all strains. Films with ...
Abstract Introduction.- Infection is the worst complication seen with inflatable penile prosthesis (IPP). Both the American Medical Systems (AMS) and Coloplast IPP have infection retardant coatings. AMS is coated at the factory with rifampicin and minocycline (InhibiZone). The Coloplast IPP has a hydrophilic coating covalently bonded to its components that will absorb any aqueous solution before implantation and provides increased surface lubricity to decrease bacterial adherence. Aim.- We tested several antibiotic dips comparing zones of inhibition (ZOI) against five commonly infecting bacteria with coated Coloplast implants. Results were compared with those ZOI created with strips of an AMS IPP precoated with InhibiZone. Methods.- Pieces of sterile Coloplast Titan IPP were dipped in (i) ...
The selection and design of an MEOR process for application in a specific field involves geological, reservoir, and biological characterization. Microbially mediated oil recovery mechanisms (bigenic gas, biopolymers, and biosurfactants) are defined by the types of microorganisms used. The engineering and biological character of a given reservoir must be understood to correctly select a microbial system to enhance oil recovery. This paper discusses the methods used to evaluate three fields with distinct characteristics and production problems for the applicability of MEOR would not be applicable in two of the three fields considered. The development of a microbial oil recovery process for the third field appeared promising. Development of a bacterial consortium capable of producing the desired metabolites was initiated, and field isolates were characterized.
Several challenges currently exist for rational design of functional tissue engineering constructs within the host, which include appropriate cellular integration, avoidance of bacterial infections, and low inflammatory stimulation. This work describes a novel class of biodegradable, amphiphilic polyanhydrides with many desirable protein-material and cell-material attributes capable of confronting these challenges. The biocompatible amphiphilic polymer films were shown to release laminin in a stable and controlled manner, promote neural cell adhesion and differentiation, and evade inflammatory responses of the immune system. Using high-throughput approaches, it was shown that polymer chemistry plays an integral role in controlling cell?film interactions, which suggests that these polyanhyd...
This paper describes a comprehensive model of wastewater treatment in secondary facultative ponds, which combines 3D hydrodynamics with a mechanistic water quality model. The hydrodynamics are based on the Navier-Stokes equation for incompressible fluids under shallow water and Boussinesq assumptions capturing the flow dynamics along length, breadth and depth of the pond. The water quality sub model is based on the Activated Sludge Model (ASM) concept, describing COD and nutrient removal as function of bacterial growth following Monod kinetics, except for Escherichia coli removal, which was modelled as first order decay. The model was implemented in the Delft3D software and was used to evaluate the effect of wind and the addition of baffles on the water flow pattern, temperature profiles i...
Since the mid-1990s, nuclear power plants in Korea have experienced wall thinning, leaks, and ruptures of secondary side piping caused by flow-accelerated corrosion (FAC). The pipe failures have increased as operating time progresses. In order to prevent the FAC-induced pipe failures and to develop an effective FAC management strategy, KEPRI and KOPEC have conducted a study for developing systematic FAC management technology for secondary side piping of all Korean nuclear power plants. As a part of the study, FAC analyses were performed using the CHECWORKS code. The analysis results were used to select components for inspection and to determine inspection intervals on each nuclear power plant. This paper describes the introduction of the FAC analysis method and the wall thinning trend analysis results by reactor type, system, and water treatment amine. This paper also represents the site application feasibility for secondary side piping ...
Numerical solutions given by a vorticity-velocity method are presented for combined free and forced laminar convection in the thermal entrance region of a horizontal rectangular channel without the assumptions of large Prandtl number and small Grashof number. The channel wall is heated with a uniform wall heat flux. Typical developments of temperature profile, secondary flow, and axial velocity at various axial positions in the entrance region are presented. Local friction factor and Nusselt number variations are shown for Rayleigh numbers Ra = 10{sup 4}, 3 {times} 10{sup 4}, 6 {times} 10{sup 4}, and 10{sup 5} with the Prandtl number as a parameter. The solution for the limiting case of large Prandtl number and small Grashof number obtained from the present study confirms the data of existing literature. It is observed that the large Prandtl number assumption is valid for Pr = 10 when Ra {le} 3 {times} 10{sup 4} but for a larger Prandtl number ...
Discussions were given on the characteristics of a diesel engine to emit unburned hydrocarbon (HC) created in a long idling operation. The engine tested in the experiment is a direct injection diesel engine with six water-cooled were investigated varying the jet hole diameter and length of the jet nozzle. In the initial operation period, the HC showed high values. This is thought because part of the injected fuel has deposited on the wall because of low combustion chamber wall temperature, and the fuel deposit that did not evaporate during combustion evaporated during expansion process and emitted unburned. The head was dismantled to investigate the carbon flowers deposited on the nozzle and the relationship between the carbon and the HC deposited on the head face and the combustion chamber wall. It was clarified that the HC increase was phenomenal compared with that of the carbon. This is because the injected fuel was ...
Vanadium alloys exhibit important advantages as a candidate structural material for fusion first wall/blanket applications. These advantages include fabricability, favorable safety and environmental features, high temperature and high wall load capability, and long lifetime under irradiation. Vanadium alloys with (3-5)% chromium and (3-5)% titanium appear to offer the best combination of properties for first wall/blanket applications. A V-4Cr-4Ti alloy is recommended as the reference composition for the ITER application. This report provides a summary of the R&D conducted during 1994 in support of the ITER Engineering Design Activity. Progress is reported for Vanadium Alloy Production, Welding, Physical Properties, Baseline Mechanical Properties, Corrosion/Compatibility, Neutron Irradiation Effects, Helium Transmutation Effects on Irradiated Alloys, and the Status of Irradiation Experiments. Separate abstracts have been ...
In 1998, in the frame of the ITER EDA phase, an European R and D Programme for the Blanket Design was implemented for developing and selecting the materials and the relevant fabrication procedures for manufacturing the shielding modules of the ITER Primary Wall. The fabrication of several Beryllium armored small scale mock-ups, reproducing representative portions of a Primary Wall panels, was also launched (Fusion Technol. (1998) 195). Further experimental activities were also programmed for investigating the thermal-mechanical behavior of these mock-ups at high heat flux and under thermal fatigue tests. In 2001, the ITER European Home Team decided to assign to ENEA a contract for the thermal fatigue testing of six mock-ups aiming at verifying the reliability of the Beryllium/Dispersion Strengthened Copper alloy/Stainless Steel and Beryllium/Precipitation hardened Copper alloy/Stainless Steel joints manufactured by solid Hot Isostatic Pressing ...
Superconducting rf cavities are increasingly used in accelerators. Gradient is a parameter of particular importance for the ILC. Much progress in gradient has been made over the past decade, overcoming problems of multipacting, field emission, and breakdown triggered by surface impurities. However, the quenching limit of the surface magnetic field for niobium remains a hard limitation on cavity fields sustainable with this technology. Further exploration of materials and preparation may offer a path to surpassing the current limit. For this purpose, we have designed a resonant test cavity. One wall of the cavity is formed by a flat sample of superconducting material; the rest of the cavity is copper or niobium. The H field on the sample wall is 75% higher than on any other surface. Multipacting is avoided by use of a mode with no surface electric field. The cavity will be resonated through a coupling iris with high-power rf at superconducting ...
Considerations for longevity of nuclear facilities and ease of decommissioning are of great importance for future nuclear power plants. To this end, a concept of an optimal structural concept for nuclear reactor buildings has been studied: the main feature of this concept is to utilize large-sized, light weight prefabricated members with ultrahigh strength materials. The following two items have been selected to study the prospective structure: (1) Applicability of ultrahigh strength materials for reinforced concrete shear walls (2) Construction using large sized prefabricated members As the first step (1), material and structural tests using ultrahigh strength materials, and the subsequent analysis of those tests for reinforced concrete shear walls, has been conducted. The positive results of this study show a bright future for the use of ultrahigh strength materials for the reinforced concrete shear walls of nuclear ...
Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet impingement shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. These leak rates depend on the crack-opening area of a through-wall crack in the pipe. In addition to LBB analyses, which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section 11. This study was requested by the NRC to review, evaluate, and refine current analytical models for crack-opening-area analyses of pipes with circumferential through-wall ...
Since the first round of conceptual fusion reactor designs in 1973 - 1974, there has been considerable progress in design improvement. Two recent tokamak designs of the Wisconsin and Culham groups, with increased plasma beta and wall loading (power density), lead to more compact reactors with easier maintenance. The Reference Theta-Pinch Reactor has undergone considerable upgrading in the design of the first wall insulator and blanket. In addition, a conceptual homopolar energy storage and transfer system has been designed. In the case of the mirror reactor, there are design changes toward improved modular construction and ease of handling, as well as improved direct converters. Conceptual designs of toroidal-multiple-mirror, liner-compression, and reverse-field pinch reactors are also discussed. A design is presented of a toroidal multiple-mirror reactor that combines the advantages of steady-state operation and high-aspect ratio. The ...
In 2001, EFDA has assigned to ENEA a contract for the thermomechanical testing of six mock-ups of the ITER primary wall module. These small scale mock-ups, reproducing representative portions of the reference ITER primary wall panels, were fabricated during ITER EDA phase by solid hot isostatic pressing (HIPping) of an AISI 316L stainless steel back structure to a alumina dispersion strengthened (DS)-Cu alloy heat sink armored with beryllium tiles. The experimental program, carried-out at ENEA Brasimone CEF 1-2 thermal hydraulic facility, was focused on the thermal mechanical testing of these mock-ups aiming at verifying which tile geometry and manufacturing procedure assures the required reliability of the beryllium/DS-Cu alloy/SS joints at high incident heat flux (>0.8 MW/m"2) both at steady state and under thermal fatigue tests. The paper presents the progress in the experimental activity of the first test campaign and the main ...
The authors investigate the optimisation of solar-heated cavity receivers in which solar energy collected by a paraboloid collector is converted into electrical energy. The focussed solar energy enters the receiver through an aperture to heat the working fluid, which flows inside the receiver tubes and is compressed by the compressor of a gas turbine system, to the highest process temperature. A method of calculating the distribution on the inner receiver surfaces of the solar radiation reflected by the paraboloid collector is presented to begin with. The interchange of radiant energy inside the receiver cavity can be calculated on this basis, including the radiation loads, the temperatures of the inner receiver walls, and the radiative and convective losses. The temperature fields in the tube walls must be known for determining the strength required of receiver tubes; they can be derived from the useful heat which comprises a directed ...
Laboratory experiments were conducted to simulate the transfer of acidic THOREX waste from Tank 8D-4 into the alkaline PUREX waste in Tank 8D-2 at West Valley. The purpose of the experiments was to explore means of minimizing the production of nitric oxide (NO) gas during mixing of the two wastes and to assess the potential for the gas to further react in the vapor space possibly leading to enhanced corrosion of the tank walls. Forty one THOREX/PUREX mixing tests were conducted to explore the effects of stirring rate, pH, THOREX addition rate, THOREX or PUREX dilution, and temperature. The two most important criteria for minimizing NO production were to maintain some degree of agitation and the keep the pH in the PUREX high, preferably >12. Steel corrosion tests were performed in the presence of low partial pressures of NO{sub 2} and liquid water or water vapor. The NO{sub 2} (from oxidation of NO in the vapor space) concentrations were representative of those ...
Certain innovative coke-oven repair techniques are reviewed that represent an engineered approach to a successful rehabilitation of all types of coke-oven batteries. These techniques have been developed during the last 10 years and experience gained on a number of repair projects has shown that these techniques operate as a cohesive and comprehensive method of end flue and through-wall repairs to gain additional years of operating life to coke-oven batteries. Extended operations approaching 10 to 15 additional years of service at lower costs than a pad-up rebuild and, while meeting the environmental emission regulations, are attainable using the techniques of: Proper tie-in joint preparation; Improved bricking up methodology; Preheating refractory during bricking up; Installation of spring-loaded bracing system; and installation of flexible coke-oven doors. Repair methods that do not incorporate the above techniques are subject to premature failure of the ...
Presented in this paper is the transient analysis of a Group Distribution Header (GDH) following a guillotine break at the end of the header. The GDH is the most important component of reactor safety in case of accidents. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the GDH into the ECCS. The GDH that is propelled into motion after a guillotine break can impact neighboring GDH pipes or the nearest wall of the compartment. The cases of GDH impact on an adjacent GDH and its attached piping are investigated in this paper. A whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is modeled using finite elements. The finite element code NEPTUNE used in this study enables a dynamic pipe whip structural analysis that accommodates large displacements and nonlinear material characteristics. The results of the study indicate that a whipping GDH pipe would ...
Stress corrosion cracks have been discovered in Group Distribution Headers (GDH) at the Ignalina and Chernobyl Nuclear Power Plants. This increases the probability that a guillotine pipe break can occur that creates a whipping pipe (GDH) with the potential to damage surrounding structures-i.e. adjacent GDH and its attached piping or adjacent reinforced concrete compartment wall. The GDH is the most important component for reactor safety in case of an accident. Emergency Core Cooling System (ECCS) piping is connected to the GDH piping such that, during an accident, coolant passes from the ECSS into the GDH. Presented in this paper is the transient analysis of a Group Distribution Header following a guillotine break at the blind end of the header. Using a very conservative force loading function, the transient response of a whipping RBMK-1500 GDH along with neighboring concrete walls and pipelines is obtained using finite element methodology. The ...
This patent describes a system adapted for alternative use as a diverter or a blowout preventer for a bottom supported drilling rig and adapted for positioning beneath a rotary table of the drilling rig, the system comprising: a fluid flow controller having a controller housing with a lower opening and an upper opening and a vertical flow path therebetween and an outlet passage provided in its housing wall, and at least two bases. A method is described for installing a system adapted for alternative connection as a diverter or a blowout preventer for a bottom supported drilling rig positioned beneath a rotary table of the drilling rig after structural casing has been set in a borehole. The method comprises: positioning a first telescoping spool having a lower end and an upper end below the rotary table, the first spool having a first base disposed at its upper end, the first base having a port disposed in its wall; aligning a fluid flow ...
Specimen strips of pure alpha titanium and beta titanium alloy were exposed to a range of up to 46 deuterium plasma discharges in the Princeton Large Torus Tokamak (PLT) under simulated first wall conditions, and the amount of trapped deuterium in these specimens was measured, using carbon as a calibration standard for trapping. The Deuterium Nuclear Microprobe was used to study the total trapped deuterium and the deuterium depth distribution in the exposed materials before and after annealing at 373 and 423"0K. The Scanning Auger Microprobe was used to identify the effects of surface impurities on the deuterium distribution. Results indicate that about 20 to 40% of the incident deuterium was trapped by the surface and about 90% of the trapped deuterium remained in a 20A carbonaceous film deposited during plasma exposure. Annealing resulted in a gradual loss from the film. These results indicate the importance of impurity film formation which may play a dominating ...
We compared the values of the myocardial thickness and the left ventricle diameters measured with MRI and echocardiography. The ejection fraction was compared in MRI and ventriculography. 34 patients with different heart dysfunctions were examined with MRI (FISP 2D sequence). 26 of them were also studied by echocardiography and 20 by biplane cine-ventriculography. The enddiastolic thicknesses of the left ventricular postero-lateral wall and of the septum interventriculare were measured on short axis images. An ellipsoidal modell was used for volume calculation and ejection fraction. Correlation of MRI values of thickness and ejection fraction with echocardiographi and angiographi showed r>0,8. As known for 1.56 T Imagers, the myocardial thickness in MRI was underestimated compared to echocardiography (1.4 mm#+-#1.7). The ejection fraction was underevaluated compared to ventriculography (4.5%#+-#10.1). MRI (1.0 T) accurately measures ventricular ...
Desorption behavior of pyrene, phenanthrene and naphthalene from fullerene, single-walled carbon nanotubes (SWCNTs) and multi-walled carbon nanotubes (MWCNTs) was examined. Available adsorption space of carbon nanotubes (CNTs) was found to be the cylindrical external surface, neither the inner cavities nor inter-wall spaces due to impurities in the CNTs and restricted spaces (0.335 nm) of the MWCNTs, respectively. Desorption hysteresis was observed for fullerene but not for CNTs. Deformation-rearrangement was proposed to explain the hysteresis of polycyclic aromatic hydrocarbons (PAHs) for fullerene, due to the formation of closed interstitial spaces in spherical fullerene aggregates. However, long, cylindrical carbon nanotubes could not form such closed interstitial spaces in their aggregates due to their length, thus showing no significant hysteresis. High adsorption capacity and reversible adsorption of PAHs on CNTs ...
Throughout the DOE complex there are numerous facilities that handle hazardous and radioactive waste solutions. Due to the hazardous constituents of the mixed waste, secondary containment of tank systems and their ancillary piping, in accordance with Resource Conservation and Recovery Act, is a concern for such existing facilities. The Idaho Division of Environmental Quality was petitioned in 1990 for an Equivalent Device determination regarding secondary containment of waste lines embedded in interior concrete walls. The petition was granted; however, it expires in 1996. To address the secondary containment issue, additional studies were undertaken. One study verified the hypothesis that an interior wall pipe leak would follow the path of least resistance through the naturally occurring void found below a rigidly supported pipe and pass into an adjacent room where detection could occur, before any significant deterioration of the concrete ...
The purpose of this study is to identify the radiative heat transfer augmentation by a coaxial cylinder introduced in the infinite cylindrical pipe enclosing a participating gas. The gas is either a mixture of water vapor and carbon dioxide or gray. The gas is assumed to be homogeneous at a constant temperature, and has a refractive index of unity. All of the surfaces are opaque and gray, diffusely emitting and reflecting at a constant temperature. The effect of system diameter, diameter ratio, wall emittances, gas and surface temperatures, mixture component on heat transfer augmentation are studied by using the zone method with participating gas radiative properties evaluated from the weighted sum of gray gases model. From the radiative equilibrium condition, the installed wall temperature is formulated and calculated by the iteration method. If the medium is a gray gas, the augmentation observed are negligible. For the range of values studied ...
For almost 150 years, the two monotypic genera Trochodendron and Tetracentron (Trochodendraceae) have been considered to share an unusual and primitive feature in angiosperms - the lack of vessels in their wood. Therefore, they have been classified in a basal position in the angiosperms. Our observations by light microscopy, low-vacuum environmental scanning electron microscopy (ESEM) and high-vacuum scanning electron microscopy (SEM) both in fresh and FAA-fixed materials consistently showed the presence of tracheary elements differentiated into two types in both genera. In Trochodendron, the tracheary elements can be divided into perforate vessel elements and imperforate fiber-tracheids and tracheids. The vessel elements show end and lateral walls. The pits on the end walls are elongate- ...
A pump down model for a vacuum chamber with a reversibly adsorbed phase is presented. The outgassing equation which predicts the variation of coverage at the wall surface of a vacuum chamber with time is derived. Then the measured and the true outgassing rates are defined. The theoretical measured outgassing rate shows only a very weak dependence for pumping speed. This prediction is opposite to the experimental result that the measured outgassing rate depends significantly on pumping speed. It is discussed that the experimental measured outgassing rate must be described as the product of the effective pumping speed and the measured pressure in the pumped chamber, in which the measured pressure is equivalent to the equilibrium pressure of the wall surface described by the equilibrium adsorption isotherm as a function of the shifted surface coverage {theta}-{delta}{theta} by a small coverage {delta}{theta} from the coverage of a pumping point ...
A highly sensitive and stable tris(2,2prime-bipyridyl)ruthenium(II) (Ru(bpy)32+) electrogenerated chemiluminescence (ECL) sensor was developed based on carbon nanotube (CNT) dispersed in mesoporous composite films of sol-gel titania and perfluorosulfonated ionomer (Nafion). Single-wall (SWCNT) and multi-wall carbon nanotubes (MWCNT) can be easily dispersed in the titania-Nafion composite solution. The hydrophobic CNT in the titania-Nafion composite films coated on a glassy carbon electrode certainly increased the amount of Ru(bpy)32+ immobilized in the ECL sensor by adsorption of Ru(bpy)32+ onto CNT surface, the electrocatalytic activity towards the oxidation of hydrophobic analytes, and the electronic conductivity of the composite films. Therefore, the present ECL sensor based on the CNT-...
Abstract Purpose: To evaluate the efficacy of transvesical obturator nerve block (ONB) in the prevention of obturator nerve reflex and leg jerking during transurethral resection of bladder tumors (TURBT). Patients and Methods: A total of 60 patients were studied, in whom the transurethral resection of tumors on the posterolateral bladder wall were performed under spinal anesthesia (SA). The patients were randomly divided into two groups. In the first group, we performed transvesical ONB and SA together, while the second group received only SA. The patients underwent TURBT using monopolar cautery. Incidence of leg jerking was registered and compared in these two groups. We used a nerve stimulator to detect the obturator nerve next to the lateral bladder wall. The obturator nerve was identif...
The buckling behaviors of double-walled carbon nanotubes (DWCNTs) under torsion are investigated by using molecular dynamics (MD) simulations. The effect of length on the torsional buckling behaviors of DWCNTs is examined for the first time. The simulation results show that the DWCNTs experience gradual or simultaneous buckling deformations depending on their lengths. In addition, the effect of the inner tube in a DWCNT on its torsional buckling behavior is also examined. The presence of the inner tube triggers van der Waals (vdW) interactions between it and the outer tube and thus leads to a stiffening effect of the DWCNT against torsional deformation. Whether the ends of the inner tube are free or fixed and whether it is subject to a torque or not, the critical torque and the critical torsional angle of the outer tube are only marginally affected.
Solar cavity receiver plays a dominant role in the light-heat conversion. Its performance can directly affect the efficiency of the whole power generation system. A combined calculation method for evaluating the thermal performance of the solar cavity receiver is raised in this paper. This method couples the Monte-Carlo method, the correlations of the flow boiling heat transfer, and the calculation of air flow field. And this method can ultimately figure out the surface heat flux inside the cavity, the wall temperature of the boiling tubes, and the heat loss of the solar receiver with an iterative solution. With this method, the thermal performance of a solar cavity receiver, a saturated steam receiver, is simulated under different wind environments. The highest wall temperature of the boi...
Results are presented from a numerical model of the steady-state energy transfer in molten-salt-in-tube solar cavity receivers that includes convective energy transfer at a local (spatially resolved) level. Molten salt energy absorption and gray radiative transfer between all cavity surfaces are also included. This model is applied to the Molten Salt Subsystem Component Test Experiment (MSS/CTE) cavity receiver. Results for this receiver indicate the global (entire cavity) receiver thermal efficiency is invariant within a few percent to most parameters investigated, although front surface temperatures of the nonabsorbing walls vary considerably, and are particularly sensitive to the type of convective submodel used. Absorption efficiencies indicate the effects of the cavity enclosure environment. For all conditions investigated, tube inner wall temperatures remain under 855 K, ensuring that the salt remains chemically stable.
Biosorption of elements is a little understood phenomenon exhibited by some types of even nonliving microbial biomass. A common fungus Rhizopus arrhizus has been reportd to take up uranium from adqueous solutions to the extent of 180 mg U/sup 6 +//g. The mechanism of uranium sequestering by this type of biomass was studied by using experimental techniques such as electron microscopy, x-ray energy dispersion analysis, IR spectroscopy, and supporting evidence was obtained for a biosorption mechanism consisting of at least three processes. Uranium coordination and adsorption in the cell-wall chitin structure occur simultaneously and rapidly whereas precipitation of uranylhdroxide within the chitin microcrystalline cell-wall structure takes place at a lower rate. Interference of Fe/sup 2/ and Zn/sup 2 +/ coions with uranium biosorption is indicated.
Inactive cells of Rhizopus arrhizus have been documented to exhibit a high thorium biosorptive uptake (170 mg/g) from aqueous solutions. The mechanism of thorium sequestering by this biomass type was investigated following the same method as for the uranium biosorption emchanism. The thorium sequestering mechanism appeared somewhat different from that of uranium. Experimental evidence is presented which indicates that, at optimum biosorption pH (4), thorium coordinates with the nitroge of the chitin cell wall network and, in addition, more thorium is adsorbed by the external section of the fungal cell wall. At pH 2 the overall thorium uptake is reduced. The kinetic study of thorium biosorption revealed a very rapid rate of uptake. Unlike uranium at optimum solution pH, Fe/sup 2 +/ and Zn/sup 2 +/ did not interfere significantly with the thorium biosorptive uptake capacity of R. arrhizus.
Scanning electron microscope (SEM) is necessary to demonstrate presence or absence of pit membranes in possible perforations or the type of pit membrane remnants in perforations in vessel element end-walls of angiosperms, but it was unconfirmed and questionable whether pit membrane absence in pits was affected by the processing and handling before SEM observations. To solve this question, the secondary xylem of four woody species from primitive angiosperms, Illicium henryi Diels. (Illiciaceae), Schisandra rubriflora (Franch.) Rehd. et Wils. (Schisandraceae), Tetracentron sinensis Oliv. and Trochodendron aralioides Sieb. & Zucc. (Trochodendraceae) was chosen and the following techniques were used: (1) fresh materials were examined in low-vacuum with ESEM. (2) Air-dried materials were examin...
Test Blanket Modules (TBM) will be tested in ITER to verify the capability of tritium breeding and recovery and the extraction of thermal energy suitable for the production of electricity. A Helium Cooled Solid Breeder (HCSB) TBM has been developed in Korea to accomplish these goals. Reduced Activation Ferritic/Martensitic (RAFM) steel has been chosen as the primary candidate structural material for Korean TBM. Due to the complexity of the First wall (FW) and Side wall (SW), it is necessary to develop various joining technologies, such as Hot Isostatic Pressing (HIP), Electron Beam Welding (EBW) and Tungsten Inert Gas (TIG) welding, for the successful fabrication of TBM. In this study, the mechanical properties of TIG welded RAFM steel were investigated. Various mechanical tests of TIG-welded RAFM steel were performed to obtain the optimized TIG welding process for RAFM steel
Nowadays, different research teams are engaged on experimental and theoretical studies having as main aim the evaluation of seismic performance of sheathed cold-formed steel frame structures. Although a relatively large number of experimental and theoretical studies are available, the development of useful tools for the seismic design should be improved. As an attempt to overcome this lack, this paper aims to present a structural design procedure that allows, through the definition of three design nomographs, the screw spacing and all the shear walls components to be obtained on the basis of linear dynamic or nonlinear static seismic analysis. In addition, a procedure for the prediction of the whole pushover response curve of sheathed cold-formed steel shear walls, which can be advantageou...
In the beam pipe of the positron damping ring of the Next Linear Collider, electrons will be created by beam interaction with the surrounding vacuum chamber wall and give rise to an electron cloud. Several solutions are possible for avoiding the electron cloud, without changing the bunch structure or the diameter of the vacuum chamber. Some of the currently available solutions for preventing this spurious electron load include reducing residual gas ionization by the beam, minimizing beam photon-induced electron production, and lowering the secondary electron yield (SEY) of the chamber wall. We will report on recent SEY measurements performed at SLAC on TiN coatings and TiZrV non-evaporable getter thin films.
The dielectric wall accelerator (DWA) system being developed at the Lawrence Livermore National Laboratory (LLNL) uses fast switched high voltage transmission lines to generate pulsed electric fields on the inside of a high gradient insulating (HGI) acceleration tube. High electric field gradients are achieved by the use of alternating insulators and conductors and short pulse times. The system is capable of accelerating any charge to mass ratio particle. Applications of high gradient proton and electron versions of this accelerator will be discussed. The status of the developmental new technologies that make the compact system possible will be reviewed. These include, high gradient vacuum insulators, solid dielectric materials, photoconductive switches and compact proton sources.
The physical foundations of a variety of emerging technologies --- ranging from the applications of quantum entanglement in quantum information to the applications of nonequilibrium bulk and interface phenomena in microfluidics, biology, materials science, energy engineering, etc. --- require understanding thermodynamic entropy beyond the equilibrium realm of its traditional definition. This paper presents a rigorous logical scheme that provides a generalized definition of entropy free of the usual unnecessary assumptions which constrain the theory to the equilibrium domain. The scheme is based on carefully worded operative definitions for all the fundamental concepts employed, including those of system, property, state, isolated system, environment, process, separable system, system uncorrelated from its environment, and parameters of a system. The treatment considers also systems with movable internal walls and/or semipermeable walls, with ...
In the course of designing a catalytic porous membrane reactor for experimental studies, both inside and outside of the non-reaction zones as well as the two ends of the membrane need to be completely sealed to ensure that there is no flow across the membrane in the non-reaction zone. Experiments show that up to 50% of the total flow across the membrane may be contributed by the axial flow along the wall of the non-reaction zones if only one side of the membrane is sealed. Another problem that cannot be solved by sealing is the capillary flow of the catalyst along the tube wall into the non-reaction zones when the catalyst is doped on the membrane. One of the best ways to avoid this axial flow of catalyst would be to use non-porous tubes in the non-reaction zones and join them with the porous membrane tube. In doing so, the cost of the membrane reactor could be reduced simply because shorter membrane tube is needed.
Abstract Aims: To develop a new nano composite of multi walled carbon nanotubes (MWNTs) with enhanced antimicrobial activity. Methods and Results: A novel antimicrobial nanocomposite [MWNT epilson polylysine (MEPs)] was synthesized via covalent attachment of epilson polylysine on MWNTs with hexamethylene diisocyanate (HDI) as the coupling agent. UV visible spectra and Fourier transform infrared spectra (FT IR) investigations indicate that MEPs is stable, with epilson polylysine leaching effectively eliminated. When compared to MWNTs, the new nano composite MEPs exhibits enhanced antimicrobial activities. In 20 mg l 1 suspensions, significant increases of 72 1, 64 5 and 69% against Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus can be observed. The deposited film of MEPs...
The major bottleneck for popularization and utilization of the conventional mechanical valve pulse combustors is the self-priming mode of gas supply. An aerodynamic valve (as against mechanical valve) self-excited pulse combustor of the Helmholtz-type with continuous supply of gas and air was designed and a mathematical model was established in this paper. The theoretical model employed well-stirred reactor model and a single step Arrhenius chemistry, and took those factors which might affect the combustion stability into account. The factors include the variation of the mass rate of the reactants affected by the pressure in the combustion chamber, the convective and radiation heat loss in the combustion chamber, and the heat transfer and wall friction in the tailpipe. The effect of wall t...
The switching behavior of magnetic patterns prepared by ion irradiation was investigated. Co/Pt multilayers with perpendicular anisotropy and large out-of-plane coercivities 5-6 kOe were grown on electron transparent SiN windows. Regularly spaced 1 micron sized regions, were magnetically pattered via ion beam irradiation through a stencil mask. Lorentz TEM was used to observe in-situ magnetization reversal processes of irradiated regions under well-defined applied magnetic fields. When the in-plane field was increased, domain wall motion was observed, resulting in the alignment of the patterns with the direction of the applied field. The switching mechanism of the in-plane patterns was by domain wall motion.
The junction conditions for General Relativity in the presence of domain walls with intrinsic spin are derived in three and higher dimensions. A stress tensor and a spin current can be defined just by requiring the existence of a well defined volume element instead of an induced metric, so as to allow for generic torsion sources. In general, when the torsion is localized on the domain wall, it is necessary to relax the continuity of the tangential components of the vielbein. In fact it is found that the spin current is proportional to the jump in the vielbein and the stress-energy tensor is proportional to the jump in the spin connection. The consistency of the junction conditions implies a constraint between the direction of flow of energy and the orientation of the spin. As an application, we derive the circularly symmetric solutions for both the rotating string with tension and the spinning dust string in three dimensions. The rotating ...
This research aims to develop reliable, advanced system thermal-hydraulic computer code and to quantify the uncertainties of code to introduce the best estimate methodology of ECCS for LBLOCA. Although the one of best estimate code, RELAP5/MOD3.1 was introduced from USNRC, several deficiencies in its reflood model and some improvements have been made. The improvements consist of modification of reflood wall heat transfer package and adjusting the drop size in dispersed flow regime. The tome smoothing of wall vaporization and level tracking model are also added to eliminate the pressure spike and level oscillation. For the verification of improved model and quantification of associated uncertainty, the FLECHT-SEASET data were used and upper limit of uncertainty at 95% confidence level is evaluated. (Author) 30 refs., 49 figs., 2 tabs.
The EU-home team is in charge of the R and D related to the ITER baffle first wall. Five small-scale mock-ups, using Be, CFC and W tiles and different armour/heat-sink material joints under development, have been fabricated and thermomechanically tested in FE200 (Le Creusot) and JUDITH (Juelich) electron beam facilities. The small-scale mock-ups have been submitted to thermo-mechanical fatigue tests (up to failure using accelerating techniques). The objective was to determine the performances of the armour material joints under high heat flux cycles. (orig.)
Forced convective heat transfer in a cross-corrugated channel solar air heater has been studied experimentally using air as a working fluid. The channel was formed by two transversely positioned corrugated sheets and two flat thermally insulated side walls. One corrugated sheet was heated by a radiant heater, while the other was thermally insulated. The fluid velocity and temperature, and the wall temperature and the local heat flux across the heated corrugated sheet were measured for a variety of operating flow rates. Experimental results for the channel geometry have yielded the correlation Nu = 0.0743 (Re)[sup 0.76]. This heat-transfer coefficient is about 2.8 times that of a smooth flat channel. The experiments showed that local heat transfer rate was smaller on the valley of the corrugation than that on the peak. The ratio of the local heat transfer rates on the two locations was related to the Reynolds number.
The flow and heat transfers associated with a plane laminar flow past a forward-facing step were analyzed using a power-law numerical scheme combined with a false vorticity-stream function approach. To improve the traditional wall-vorticity boundary condition, a novel method, based on an accurate description of the nonslip wall condition, was developed and utilized. The convergence for a 56 x 49 grid system was obtained in about 350 iterations. The computed reattachment distances in the upper separated region agree with the available experimental data for a blunt plate. The heat transfer augmentation is significant across the step; however, it is counterbalanced by the deterioration of heat transfer immediately upstream of the step.
Measurements of the statistical characteristics of channel wall static pressure fluctuations in parallel one-component boiling flow are reported. The measurements span a wide range of local subcooling and vapor volume fraction, and correspond to flow regimes ranging from highly subcooled bubbly to saturated slug-annular. Vapor volume fraction measurements at the pressure measurement station are also reported in conjunction with visual observation of the flow structure. Variation of static pressure fluctuation intensity and spectral content with local thermal-hydraulic condition is demonstrated. Finally, it is suggested that diagnosis of local two-phase flow regime on the basis of (i) statistical characteristics of the pressure data, and (ii) time trace of pressure signal, may be possible. 15 refs.
An experimental study was performed to investigate the heat transfer characteristics of the mixed convection flow through a horizontal rectangular channel where open-cell metal foams of different pore densities (10, 20 and 30 PPI) were situated. A uniform heat flux was applied at all of the bounding walls of the channel. For each of three values of the uniform heat flux, temperatures were measured on the entire surfaces of the walls. Results for the average and local Nusselt numbers are presented as functions of the Reynolds and Richardson numbers. The Reynolds number based on the channel height of the rectangular channel was varied from 600 to 33000, while the Richardson number ranged from 0.02 to 103, extending over forced, mixed and natural convection. Second important parameter that in...
Present paper is performed to investigate the heat and exergy transfer characteristics of forced convection flow through a horizontal rectangular channel where open-cell metal foams of different pore densities such as 10, 20 and 30PPI (per pore inches) were situated. All of the bounding walls of the channel are subjected to various uniform heat fluxes. The pressure drop and heat transfer characteristics are presented by two important parametric values, Nusselt number (NuH) and friction factor (f), as functions of Reynolds number (ReH) and the wall heat flux (q). The Reynolds number (ReH) based on the channel height of the rectangular channel is varied from 600 to 33 000, while the Grashof number (GrDh) ranged from approximately 105-107 depending on q. Based on the experimental data, new em...
A linear diffusion model serves as the basis for determination of an effective radon diffusion coefficient in concrete. The coefficient was needed to later allow quantitative prediction of radon accumulation within and behind concrete walls after application of an impervious radon barrier. A resolution of certain discrepancies noted in the literature in the use of an effective diffusion coefficient to model diffusion of a radioactive gas through a porous medium is suggested. An outline of factors expected to affect the concrete physical structure and the effective diffusion coefficient of radon through it is also presented. Finally, a field method for evaluating effective radon diffusion coefficients in concrete is proposed and results of measurements performed on a concrete foundation wall are compared with similar published values of gas diffusion coefficients in concrete. (author).
The development of new electro-optical instrumentation for studying the annular dispersed two-phase flow regime is described. The system measures the thickness of the water film and droplet size and velocity distributions which would be encountered in such a flow regime. The water film thickness is measured by an improved capacitance method with a short time constant using newly developed sensor electrodes. The electrodes are made flush with the inner wall of a cylindrical tube and do not disturb the flow. In the test equipment, steady, laminar flow of water along the inner wall of the tube is controlled by appropriate valves and a porous jacket while droplets are introduced by means of a special spray nozzle.
The two-sonde neutron-logging device RKS-2 registers the ratios of the indications of two sondes and is scaled in units representing the total water content of pure limestone when saturated with fresh water. When analyzing the results of the measurements in real wells, it is necessary to calculate the effect of well- and strata conditions on the results of porosity determination. The results of simulated measurements are presented, on the basis of which correction factors are immediately determined for the calculation of the effect of the diameter of the well, and the effect of the mud cake on the well wall. A nomogram is constructed and substantiated; its purpose is the calculation of the effect of the following on the RKS-2 indication: the diameter of the well, the mud cake on the well wall, the density of the drilling solution, temperature, pressure in the well, and the lithology of the rock.
The optical birefringence of rod-like nematogens (7CB, 8CB), imbibed in parallel silica channels with 10 nm diameter and 300 micrometer length, is measured and compared to the thermotropic bulk behavior. The orientational order of the confined liquid crystals, quantified by the uniaxial nematic ordering parameter, evolves continuously between paranematic and nematic states, in contrast to the discontinuous isotropic-to-nematic bulk phase transitions. A Landau-de Gennes model reveals that the strength of the orientational ordering fields, imposed by the silica walls, is beyond a critical threshold, that separates discontinuous from continuous paranematic-to-nematic behavior. Quenched disorder effects, attributable to wall irregularities, leave the transition temperatures affected only marginally, despite the strong ordering fields in the channels.
The surface permeability of concrete walls and floors in houses was measured with a specially designed permeameter, based on measuring the air-flow induced by a pressure difference across a temporary test seal applied to a surface. The permeability of bulk concrete is 10"-"1"6 m"2. Areas free of surface defects had permeability ranging from 10"-"1"4 to 10-"1"6 m"2. However, surface defects are common on concrete wall surfaces, which increase the permeability to >10"-"1"2 m"2. This is too high for standard seal designs to be adequate as the only method of soil gas and radon exclusion. Satisfactory seals require either extended contact width or mechanical removal of the surface layer. (orig.). (2 figs., 1 tab.).
The need to increase efficiency of volumetric receivers for use in solar power plants by reducing reradiation losses and increasing the ``volumetric effect`` has promoted the idea of a receiver with tapered ducts. These seems to be very promising since higher efficiency and considerable saving of material can be achieved, as compared to conventional receivers perforated with ducts of constant cross-section. A finite element program is being developed to calculate stationary heat transfer in the tapered ducts by free and forced convection in the gas flow, conduction in walls and in the gas, and solar and thermal radiation. Gas and wall temperatures are considered to be varying only in the flow direction. In order to perform the highly nonlinear calculations of radiative exchange, the exact knowledge of the view factors is necessary. The aim of the present work is to evaluate analytically the view factors in tapered ducts.
The application of the phased array technique was limited to heavy and thick wall components as present in the nuclear industry. With the improvement of the equipment and probes other application areas are now open for the phased array technique, e.g. the inspection of the turbine blade root, weld inspection in a wall thickness range between 12 and 40 mm, inspection of aircraft components, inspection of spot welds or inspection of concretes. The aim of the use of phased array techniques has not been changed related to the first applications, i.e. the adaptation of the sound beam to the geometry by steering the angel of incidence or the skewing angle as well as the focussing of sound fields. Due to the fact, that the new applications of the phased array techniques in some cases don't leave the laboratories for the time being, the examples of this contribution will focus applications with practical background. (orig.)
Field investigations of major and damaging ice jamming on the Saint John River at Dickey, Maine , and at Sainte-Anne de-Madawaska, New Brunswick, in 1991, were described. The investigations included measurement of water surface profiles and shear wall heights at both sites. The measurements were supplemented by information from local observers and data collection agencies. Using a simplified equilibrium analysis, ice jam thickness and water level at the Dickey site was found to be generally in agreement with observed values. At Sainte-Anne-de-Madawaska sufficient data was obtained to construct and calibrate the numerical model RIVJAM which determined the configuration of the jam in nonequilibrium reaches. Use of the model enabled the successful reproduction of a measured water profile along the jam and the prediction of the approximate thickness of the jam, which was generally less than the measured shear wall height. 14 refs., 11 figs.
Placental insufficiency, inducing hypoxia-ischaemia, is considered a major cause of neuronal injury and impaired post natal development. Placental insufficiency alters the metabolism of arachidonic acid and its oxidation products. Premature labour and low-birth-weight infants are associated with reduced intrauterine blood-flow and infections of the reproductive tract. Thyroidal activity is depressed in undernutrition (placental insufficiency). Premature infants require extra vitamin C for normal tyrosine metabolism (tyrosine is the thyroxine precursor). Among the symptoms indicating infantile cretinism, which appear during 3-5 months of age are: delayed union of skull bones, torpid behaviour, slow feeding, cyanosis during feeding, excessive sleepiness, enlarged tongue, umbilical herniation, flabby musculature, short stature and delayed development. These symptoms have all been described in low-birth-weight infants and sudden infant death syndrome victims by various authors. Bacteria ...
Propionibacterium freudenreichii ET-3 culture, a cell-free product of whey fermentation using P. freudenreichii ET-3 (7025), has been shown to promote the growth of Bifidobacteria through the action of 1,4-dihydroxy-2-naphthoic acid (DHNA), and therefore, has potential use in the food and supplement industries. Although currently used as a food ingredient in Japan, the safety of this novel ingredient has not been previously evaluated through traditional toxicity testing. Therefore, here we report the results of standard toxicological testing performed on P. freudenreichii ET-3 culture. In a 4-week oral toxicity study, administration of 6000mg/kg body weight/day P. freudenreichii ET-3 culture was without compound-related adverse effects on clinical signs, body weights, food consumption, ophthalmology, hematology, clinical chemistry, urinalysis, organ weights, and gross and microscopic findings in male and female Sprague-Dawley rats. Furthermore, in vitro mutagenicity testing ...
The complexity and diversity of the microbial communities in biogranules from an upflow anaerobic sludge blanket (UASB) bioreactor were determined in response to short-term changes in substrate feeds. The reactor was fed simulated brewery wastewater (SBWW) (70% ethanol, 15% acetate, 15% propionate) for 1.5 months (phase 1), acetate / sulfate for 2 months (phase 2), acetate-alone for 3 months (phase 3), and then a return to SBWW for 2 months (phase 4). Performance of the reactor remained relatively stable throughout the experiment as shown by COD removal and gas production. 16S rDNA, methanogen-associated mcrA and sulfate reducer-associated dsrAB genes were PCR amplified, then cloned and sequenced. Sequence analysis of 16S clone libraries showed a relatively simple community composed mainly of the methanogenic Archaea (Methanobacterium and Methanosaeta), members of the Green Non-Sulfur (Chloroflexi) group of Bacteria, followed by fewer numbers of Syntrophobacter, Spirochaeta, ...
The objective of this work is to determine the ability of indigenous bacteria from a Venezuelan oil field to grow under reservoir conditions inside a porous media, and to produce metabolites capable of recovering residual crude oil. For this purpose, samples of formation waters from a central-eastern Venezuelan oil reservoir were enriched with different carbon sources and a mineral basal media. Formation water was used as a source of trace metals. The enrichments obtained were incubated at reservoir temperature (71{degrees}C), reservoir pressure (1,200 psi), and under anaerobic conditions for both outside and inside porous media (Berea core). Growth and metabolic activity was followed outside porous media by measuring absorbance at 660 nm, increases in pressure, and decreases in pH. Inside porous media bacterial activity was determined by visual examination of the produced waters (gas bubbles and bacterial cells). All the carbohydrates tested ...
The failure of receivers has been one of the main operating problems at the White Cliffs solar thermal power plant. This Technical Note reports the results of an initial investigation that identifies the cause as having been their thermal fatiguing of the tube walls. The fatigue appears to be caused by unstable heat transfer at vapor qualities below the point where critical heat flux is generally exceeded. Methods for avoiding this problem are tested.
The nucleon axial charge is calculated as a function of the pion mass in full QCD. Using domain wall valence quarks and improved staggered sea quarks, we present the first calculation with pion masses as light as 354 MeV and volumes as large as (3.5 fm)3. We show that finite volume effects are small for our volumes and that a constrained fit based on finite volume chiral perturbation theory agrees with experiment within 5% statistical errors.
Streptococcus pyogenes is an important human pathogen and surface structures allow it to adhere to, colonize and invade the human host. Proteins containing leucine rich repeats (LRR)...Full Text Available
Zircaloy fabrication plant manufactures all the necessary Zr-2 components like fuel canning tubes, calandria tubes and other rod and sheet products. This plant is having a capacity of producing about 4 lakh nos. of PHWR fuel tubes per annum. These tubes are seamless, thin walled with close dimensional tolerances and stringent mechanical properties. The plant has established all the facilities required to produce these tubes with required quality.
The spin-up problem of He II in a cylindrical container of infinite and finite height is considered on the basis of the Hall-Vinen-Bekarevich-Khalatnikov equations. The boundary conditions include the assumption of the generation of superfluid vorticity at the walls of the container. In the lowest order approximation with respect to viscosity, the problem is reduced to a Stefan problem for a single diffusion-type equation. Examples of solutions are given which show that the method used gives a good insight into the physical development of the spin-up flow.
The usefulness of helical CT early phase images optimized by the SmartPrep method for evaluation of wall invasion by colorectal cancer was investigated. Between August 1997 and September 1998, CT was performed to evaluate the primary tumor and local extension in 10 consecutive patients with colorectal cancer confirmed by barium enema- and/or colonoscopy. Early-phase images were acquired by using SmartPrep application software. This method allows the optimal scan delay time to be obtained by continuous monitoring of increases in CT values after injection of contrast medium. Sections of the surgical specimens, close to the same plane as the CT images, and of the same slice thickness, were analyzed histopathologically. All 10 cancers, regardless of size, showed strong enhancement on the early-phase images (81.4-112 HU, mean: 95.1 HU). The strongly enhanced image areas on CT corresponded to the primary cancer areas on histopathological specimens. A low-density zone was ...
A phenomenological model of the heat transfer in direct injection diesel engines was developed. Utilizing the thermodynamic results of a combustion model as an input, the model is able to predict the temporal variation of the heat losses from the cylinder gas to the cylinder walls. Additionally, the division into isothermal combustion chamber subsurfaces allows the consideration of the spatial variation of the wall heat fluxes. The physical mechanisms such as flow dependent convection, heat radiation due to hot soot particles and isolation effects of deposited soot layers are described in detail. Thus the effects of these mechanisms on the overall heat transfer can be studied. The heat transfer model was verified successfully by the comparison to measured wall heat fluxes in a single-cylinder direct injection diesel engine. It is shown that the effects of engine speed and load, turbocharging and soot deposition can be ...
Gyrokinetic particle simulation of edge pedestal formation and plasma rotation dynamics will be presented, and compared with experimental observations. Realistic tokamak edge geometry is used which include separatrix/X-point and material wall from EFIT g-eqdsk data. In order to handle adequately the spatially inhomogeneous electric potential in the scrape-off region, the full-f electron technique is used, in addition to the full-f ions. Monte Carlo neutral particles with wall recycling coefficient will be included self-consistently with the plasma kinetics. Ion-ion Coulomb collisions will be particle, momentum and energy conserving. Energy source for the pedestal and scrape-off plasmas is the heat flow from the core plasma, and the particle source is the ionization of the neutral atoms which are either wall recycled and/or gas puffed. The simulation will be self-consistent with the first principles nonlinear neoclassical ...
Stereoscopic Particle Image Velocimetry (PIV) measurements are made in horizontal planes in a simplified scale model of a spray dryer using water as fluid. The sample rate was sufficient to resolve phenomena at lower frequencies. Data reveal asymmetric velocity fields in both mean fields and dynamics. Data were analysed using Proper Orthogonal Decomposition (POD). An important periodic event is an elongation of the jet core cross section that results in a downstream displacement of the jet towards the chamber wall.
Full text of publication follows: As the coolant experiences no phase change in the core, SCWRs, unlike LWRs, cannot use design criteria based on the critical heat flux concept. The commonly accepted practice in SCWRs is to specify cladding temperature limits that must be met during transient and accident events. Therefore for the design of the SCWR, it is very important to predict the heat transfer coefficient to the supercritical water coolant with great accuracy. Our recent study focuses on the critical issue of measuring heat transfer to supercritical water at prototypical SCWR conditions and to develop the tools to predict the SCWR thermal behavior. A heat transfer test loop using a surrogate fluids, CO_2, is under construction. The reason of using CO_2 instead of water is that (i) valuable insight of the physical phenomena can be obtained with this fluid, and (ii) some existing facilities already used surrogate fluids, which in general have lower critical pressure and ...
We present a high-statistics calculation of nucleon electromagnetic form factors in N{sub f}=2+1 lattice QCD using domain wall quarks on fine lattices, to attain a new level of precision in systematic and statistical errors. Our calculations use 32{sup 3}x64 lattices with lattice spacing a=0.084 fm for pion masses of 297, 355, and 403 MeV, and we perform an overdetermined analysis using on the order of 3600 to 7000 measurements to calculate nucleon electric and magnetic form factors up to Q{sup 2{approx_equal}}1.05 GeV{sup 2}. Results are shown to be consistent with those obtained using valence domain wall quarks with improved staggered sea quarks, and using coarse domain wall lattices. We determine the isovector Dirac radius r{sub 1}{sup v}, Pauli radius r{sub 2}{sup v} and anomalous magnetic moment {kappa}{sub v}. We also determine connected contributions to the corresponding isoscalar observables. We extrapolate these ...
...who trains at the University, lines up in the pole vault alongside Steve Lewis in the men's competition, who also trains at the Loughborough High performance Athletics Centre. Loughborough alumni Victoria Barr, Hayley Jones, Lee McConnell and Kim Wall are all in the British women's 4x400m relay ...
... Westinghouse Electric is already majority owned by Toshiba Corp the maker of flash memory chips, laptops, nuclear reactors and rice cookers and Shaw Group. A deal could erase any U.S. ownership of Westinghouse, the Wall Street Journal said. Shaw partnered with Toshiba, and another Japanese company to buy Westinghouse from British Nuclear Fuels PLC for $5.4 billion five years ago, the paper ...
The calculations with the broad-group cross-section library Bugle-96, and atom displacement (dpa) cross sections for iron, both derived from ENDF/B-VI data, result in higher calculated fast neutron fluxes, better agreement of calculations with radiometric dosimeter measurements, and significantly slower dpa rate attenuation through pressure vessel walls relative to the results with their predecessors: the Sailor library and ASTM iron dpa cross sections.
Characteristics of pressure drop and heat transfer have been investigated for a lithium single-phase flow and a helium-lithium two-phase flow in a horizontal conducting circular channel in the presence of a uniform transverse magnetic field up to 1.4 T as related to the lithium cooling for magnetic-confinement fusion reactors. By the application of the magnetic field to the lithium single-phase flow, remarkable heat transfer enhancement has been observed at the top wall due to the suppression of the mixed convection occurring in the low Peclet number range, while appreciable heat transfer deterioration appeared in the high Peclet number range. It has been confirmed that the helium-lithium two-phase flow can reduce the high magnetohydrodynamic (MHD) pressure drop in a lithium single-phase flow, and it can provide much better heat transfer performance than that in a helium single-phase flow. In the presence of the magnetic field, heat transfer coefficient drastically ...
Solids are separated from a liquid in a gravity settler provided with inclined solid intercepting surfaces to intercept the solid settling path to coalesce the solids and increase the settling rate. The intercepting surfaces are inverted V-shaped plates, each formed from first and second downwardly inclined upwardly curved intersecting conical sections having their apices at the vessel wall.
BackgroundCotton fiber development undergoes rapid and dynamic changes in a single cell type, from fiber initiation, elongation, primary and secondary wall biosynthesis, to fiber...Full Text Available
The results of research on the evaluation of the half-bead weld repair method for use on nuclear reactor components are reviewed from data obtained on thick-section test pieces and intermediate-size pressure vessels. Material properties, the magnitude of residual stresses and the structural behavior of flawed pressure vessels are being obtained to determine the adequacy of the weld repair method for application in thick-section components.
Male rats were injected intravenously for 15 min with physiological saline (as control) (0.05 #mu#g/kg/min) or norepinephrine (NE) (0.1 #mu#g/kg/min) followed by 740 kBq of MIBG. Rats were injected for more 30 min (early stage group) and for more 4 hr (late stage group) with physiological saline or NE. Five MBq of "9"9"mTc-tetrofosmin (TF) was administered instead of MIBG in another group. The heart was isolated and uptake of MIBG or TF of right ventricle, apex, and left ventricle (divided into 8 parts) was measured. In control group, MIBG uptake of apex was significantly lower than that of lateral wall in both early and late groups. In NE group, MIBG uptake showed a tendency to decrease in both early and late groups. Compared with control group, the uptake of anterior wall in late group decreased significantly at NE 0.1 #mu#/kg/min. The TF uptake in control group was not different in each part. In NE group, the TF uptake of right ventricle ...
Between October 1990 and March 1991, 8 patients with cystic lesions in the region of the posterior bladder wall, the seminal vesicles and the prostate were examined by MRI. In all cases there was accurate characterisation of the lesion and of its anatomy. In 3 patients with abnormalities in the retrovesical space there was very good agreement with the operative findings. 4 patients were treated conservatively. In these patients there was good agreement with the findings on cystoscopy, CT and sonography. (orig.).
The most serious challenges in the design of chambers for inertial fusion energy (IFE) are 1) protecting the first wall from fusion energy pulses on the order of several hundred megajoules released in the form of x rays, target debris, and high energy neutrons, and 2) operating the chamber at a pulse repetition rate of 5-10 Hz (i.e., re-establishing, the wall protection and chamber conditions needed for beam propagation to the target between pulses). In meeting these challenges, designers have capitalized on the ability to separate the fusion burn physics from the geometry and environment of the fusion chamber. Most recent conceptual designs use gases or flowing liquids inside the chamber. Thin liquid layers of molten salt or metal and low pressure, high-Z gases can protect the first wall from x rays and target debris, while thick liquid layers have the added benefit of protecting structures from fusion neutrons thereby ...
Chondrosarcomas are the most frequently occurring primary malignant chest wall tumors. Furthermore, the lungs serve as the most frequent sites for metastases. Pulmonary metastases from sarcomas usually...Full Text Available
Calculation method for pyramidal horn radiators (PHR) with curvilinear generatrix has been developed on the basis of the theory of waveguide tapers. This method makes it possible to reduce the value of spurious reflection coefficients and transformation of the principal wave into waves of higher order modes by forming generatrixes of walls with specific curvilinearity.
Optional multiple long-axial gated blood pool SPECT images were prepared for the purpose of stereoscopic and quantitative imaging of left ventricular wall motion (LVWM). Sixteen patients with ischemic heart disease and 8 healthy subjects were imaged in 32 views in the 360 degrees position after iv injection of 740 MBq of Tc-99m-labeled human serum albumin D. The R-R interval was divided into 16. After preparing conventional oblique images, long-axial images were prepared. Shortening rate of left ventricular wall was calculated in 5 segments of the apex and base of the left ventricle. An average shortening rate in each segment was graded with a score from a minimum of 0 to a maximum of 40% or more. In the normal group, shortening rate in each segment, except for the base of the septal region, exceeded 40%. In the group of ischemic heart disease, radial shortening was capable of visualizing the degree and extent of the whole LVWM abnormality. ...
A model has been developed to predict the chemical composition of lakes that form in pyrite-bearing open-pit mines. Pyrite oxidation in wall rock releases sulfuric acid and metals, which mix with ground waters in the lake. Aqueous metal concentrations are calculated using MINTEQA2.
Helical dipole magnets are required in a project for the Relativistic Heavy Ion Collider (RHIC) to control and preserve the beam polarization in order to allow the collision of polarized proton beams. Specifications are for low current superconducting magnets with a 100 mm coil aperture and a 4 Tesla field in which the field rotates 360 degrees over a distance of 2.4 meters. A magnet meeting the requirements has been developed that uses a small diameter cable wound into helical grooves machined into a thick-walled aluminum cylinder.
Rising oil prices are a problem for the motor car industry. Now, an ambitious project has been launched in California which may become a serious competitor to gasoline and diesel engines: The Tesla Roadster, which is fuelled from simple wall sockets. (orig.)
Poncirin, flavanone glycoside, isolated from the fruit of Poncirus trifoliata, has anti-bacterial and anti-inflammatory activities. In this study, the effects of poncirin on the differentiation of mesenchymal stem cells were investigated. The C3H10T1/2 mesenchymal stem cells and primary bone marrow mesenchymal stem cells were studied. In the C3H10T1/2 cells, poncirin prevented adipocyte differentiation, as demonstrated by inhibition of cytoplasm lipid droplet accumulation and peroxisome proliferator-activating receptor-? (PPAR-?) and CCAAT-enhancer-binding protein-? (C/EBP-?) mRNA expression. By contrast, poncirin enhanced the expression of the key osteogenic transcription factors, runt-related transcription factor 2 (Runx2) and transcriptional coactivator with PDZ-binding motif (TAZ). Poncirin also enhanced expression of the osteogenic marker genes including alkaline phosphatase (ALP) and osteocalcin (OC). Poncirin increased mineral nodule formation in primary ...
In this 150-day study, chicken manure, kenaf, and white rot fungus were added to soil microcosms in an attempt to enhance the degradation of polychlorinated biphenyls. The soil was contaminated with commercial PCB mixtures. Dishes were ammended with 5% dry weight chicken manure, 1% dry weight kenaf, and 1% dry weight kenaf plus Phanerochaete chrysosporium inoculant. PCB concentrations were determined at 30 day intervals by soxhlet extraction and gas chromatography analyses. Preliminary results of microbial populations and PCB degradation are presented. At 90 days, the microcosms amended with chicken manure had significantly higher populations of bacteria, fungi, and actinomycetes. However, at 120 days, these soils underwent great reductions in actinomycete and bacterial populations. Through 60 days, the concentration of the PCBs Aroclor 1242 and 1248 had its greatest reduction in the kenaf amended soils. The concentration of Aroclor 1260 either increased or stayed ...
Thirty-six patients with acquired immunodeficiency syndrome (AIDS), who were febrile but without localizing signs, underwent indium-111 leukocyte scintigraphy 24 hours after injection of labeled white blood cells (WBCs) and were restudied 48 hours after injection of gallium-67 citrate. Fifty-six abnormalities were identified as possible sources of the fever; 27 were confirmed with biopsy. Of these 27, 15 were identified only on In-111 WBC scans (including colitis, sinusitis, and focal bacterial pneumonia); six, only on Ga-67 scans (predominantly Pneumocystis carinii pneumonia and lymphadenopathy); and six, on both studies (predominantly pulmonary lesions). In-111 WBC scanning revealed 21 of 27 abnormalities (78%) and gallium scanning, 12 of 27 (44%). If only one scintigraphic study has been performed, particularly with Ga-67, a significant number of lesions would not have been detected. The authors believe radionuclide evaluation of the febrile AIDS patient without ...
Abstract:- Escherichia coli-O157:H7 and-Salmonella-spp. are bacterial pathogens often associated with beef, and cause many cases of foodborne illness each year in the United States. During beef slaughter and processing, these bacteria may spread from the hide or intestines to the carcass. The objective of this research was to investigate the use of naturally occurring compounds citrus essential oils (CEOs) extracted from orange peel to reduce or eliminate these pathogens at the chilling stage of processing, or during fabrication. Brisket flats (used to simulate beef subprimals) were spot inoculated with approximately 6 log of surrogate generic-E. coli-cocktail (previously shown to be identical in growth and survival parameters to-E. coli-O157:H7 and-Salmonella-spp.). Following drying, CEOs...