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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

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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

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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...

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English 2009 p. 161-162 Brazil Paula, Viviane Silva de Almeida, Fabio

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BackgroundThe beta-defensin gene cluster (DEFB) at chromosome 8p23.1 is one of the most copy number (CN) variable regions of the human genome. Whereas individual DEFB CNs have been...Full Text Available

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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

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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

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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...

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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 ...

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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...

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Clinical questionWhat is the best treatment for bacterial conjunctivitis?ResultsTopical antibiotics expedite recovery from bacterial conjunctivitis....Full Text Available

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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...

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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.

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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 ...

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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

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PMID:12439520

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PMID:10923545

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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...

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The strategies employed by oral streptococci to resist the inimical influences of acidification reflect the diverse and dynamic niches of the human mouth. All of the oral streptococci are capable of rapid degradation of sugar to acidic end-products. As a result, the pH value of their immediate environment can plummet to levels where glycolysis and growth cease. At this point, the approaches for survival in acid separate the organisms. Streptococcus mutans, for example, relies on its F-ATPase, to protect itself from acidification by pumping protons out of the cells. S. salivarius responds by degrading urea to ammonia and S. sanguis produces ammonia by arginolysis. The mechanisms by which these organisms regulate their particular escape route are now being explored experimentally. The picture that emerges is that the acid-adaptive regulatory mechanisms of the oral streptococci differ markedly from those employed by Gram-negative bacteria. What remains to be ...

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Non-thermal (low-temperature) physical plasma is under intensive study as an alternative approach to control superficial wound and skin infections when the effectiveness of chemical agents is weak due to natural pathogen or biofilm resistance. The purpose of this study was to test the individual susceptibility of pathogenic bacteria to non-thermal argon plasma and to measure the effectiveness of plasma treatments against bacteria in biofilms and on wound surfaces. Overall, Gram-negative bacteria were more susceptible to plasma treatment than Gram-positive bacteria. For the Gram-negative bacteria Pseudomonas aeruginosa, Burkholderia cenocepacia and Escherichia coli, there were no survivors among the initial 10(5) c.f.u. after a 5 min plasma treatment. The susceptibility of Gram-positive bacteria was species- and strain-specific. Streptococcus pyogenes was the most resistant with 17?% survival of the initial 10(5) c.f.u. after a 5 min plasma ...

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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Studies were made on different types of packaging materials used for packing dried fish in the Philippines with a view to finding a suitable packaging material for irradiated dried fish. Among these packaging materials (polyethylene, cello/polyethylene, polyester/polyethylene, Kraft paper, polypropylene and interwoven polypropylene sacks), polyester/polyethylene laminate was the most resistant material against penetration by Dermestes carnivorous. No insect damage occurred on the dried fish packed in interwoven polypropylene lined with polyester/polyethylene laminate. The cost per sack of such packaging material having a capacity of 50-80 kg is US$ 0.50. The sack lined with polyester/polyethylene proved to be durable for surface transportation from Bacolod City to Manila (approx. 360 miles). Radiation treatment at 225 krad was effective against bacterial contamination but not effective in inhibiting mould growth. Raw fish soaked in 25% salt for ...

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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

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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

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could be attributed either to removal of bacterial competition. (the reason for adding antibiotics before adding additional carbon and ...

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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

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... 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. ...

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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

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Protein isolated from hen egg-white and functions as a bacteriostatic enzyme by degrading bacterial cell walls. First enzyme ever characterized by protein ...

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Our long-term goal is to enable highly productive plant species to extract, resist, detoxify, and/or sequester toxic heavy metal pollutants as an environmentally friendly alternative to physical remediation methods. We have focused this phytoremediation research on soil and water-borne ionic and methylmercury. Mercury pollution is a serious world-wide problem affecting the health of human and wild-life populations. Methylmercury, produced by native bacteria at mercury-contaminated wetland sites, is a particularly serious problem due to its extreme toxicity and efficient biomagnification in the food chain. We engineered several plant species (e.g., Arabidopsis, tobacco, canola, yellow poplar, rice) to express the bacterial genes, merB and/or merA, under the control of plant regulatory sequences. These transgenic plants acquired remarkable properties for mercury remediation. (1) Transgenic plants expressing merB (organomercury lyase) extract ...

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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 AECL's Underground ...

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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, ...

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Because resistance to new insecticides may develop rapidly and cross resistance is often encountered, even between insecticides of different classes, there is a continual demand for the development...Full Text Available

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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 ...

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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 ...

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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 ...

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The rice blast resistance (R) gene Pi-ta mediates gene-for-gene resistance against strains of the fungus Magnaporthe grisea that express avirulent...Full Text Available

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Not Available

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Objective: To investigate the mechanism of carbapenem resistance and the occurrence of plasmid-mediated quinolone resistance determinants qnr and aac(6′)-Ib-cr...Full Text Available

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... 31 5.4 FACTORIAL DESIGN STATISTICAL ANALYSIS..... ... resistance. o Factorial design statistical analysis gave the ...

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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

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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

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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

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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

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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

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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

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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

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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

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... 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...

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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

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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

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BackgroundThe human bacterial pathogen Campylobacter jejuni contains two subspecies: C. jejuni subsp. jejuni (Cjj)...Full Text Available

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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 ...

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Twelve Salmonella typhimurium strains resistant to broad-spectrum cephalosporins were isolated from cases of gastroenteritis during 1996 to 1998 in Russia, Hungary, and Greece. Resistance...Full Text Available

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To determine who resists sexual assault and what happens, data were examined from a probability sample of 3,132 adult community residents of Los Angeles, California. Seventy-five per cent of the respondents...Full Text Available

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Pyrethroid insecticides have been extensively used in China and worldwide for public health pest control. Accurate resistance monitoring is essential to guide the rational use of insecticides and resistance...Full Text Available

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Antimicrobial resistance is an emerging problem among nosocomial bacteria. Risk factors for the recovery of ceftriaxone-resistant (CRCF) or -susceptible (CSCF) Citrobacter freundii...Full Text Available

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In methicillin-resistant Staphylococcus aureus, the methicillin resistance gene mecA is localized within a large chromosomal region which is absent in the methicillin-susceptible...Full Text Available

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...visible damage. (k) Corrosion resistance. Each metal part of a...evidence of salt-spray corrosion resistance equal to or greater than...sample of test metal must show corrosion resistance equal to or better than...

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The development of several DDT-resistant strains of Anopheles atroparvus is described. They were selected by larval treatment only (RL), selection of larval and adult females (RLAF),...Full Text Available

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The resistance to pitting of a Fe-17%Cr alloy in Cl[sup [minus

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A strain of Pseudomonas syringae was recently identified as the cause of a new foliar blight of impatiens. The bacterium was resistant to copper compounds, which are used on a variety...Full Text Available

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WHAT IS ALREADY KNOWN ABOUT THIS SUBJECTA genetic basis for aspirin resistance has been postulated to exist.The...Full Text Available

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In this work we conducted both in vitro and in vivo experiments to examine the development and mechanisms of erythromycin (Ery) resistance in Campylobacter jejuni and Campylobacter...Full Text Available

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We compared the incidence of nasopharyngeal colonization by Streptococcus pneumoniae, the serotypes causing mucosal and invasive diseases, and the antibiotic resistance of these strains...Full Text Available

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Introduction:The purpose of this study was to utilize an in vitro biofilm model of subgingival plaque to investigate resistances in subgingival biofilm...Full Text Available

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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 ...

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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...

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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...

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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 ...

British Library Electronic Table of Contents (United Kingdom)

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...

Energy Technology Data Exchange (ETDEWEB)

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.

British Library Electronic Table of Contents (United Kingdom)

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...

British Library Electronic Table of Contents (United Kingdom)

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...

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The high temperature abrasive wear resistant of the composites with different Al{sub 2}O{sub 3} volume fractions, particle coating and size were investigated and the failure action of composites under different conditions at high temperature was analyzed. The results showed that the high temperature abrasive wear resistant of composite with Ni coating and wide size and 39% volume fraction of particle is the best among all composites examined. (orig.)

Science.gov (United States)

PMID:20681969

KoreaScience (Korea)

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Energy Technology Data Exchange (ETDEWEB)

No abstract prepared.

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Necessary theoretical foundation is given for the treatment of magnetic stresses applied to

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KoreaScience (Korea)

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Wastenet

colonies known as biofilms are known to harbour food-borne pathogens . These biofilms also have an increased resistance

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KoreaScience (Korea)

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British Library Electronic Table of Contents (United Kingdom)

We quantified the resistance levels of transgenic rice plants, expressing Myxococcus xanthus protoporphyrinogen oxidase (PROTOX) in chloroplasts and mitochondria, to PROTOX inhibitors, acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon. We also determined whether active oxygen species-scavenging enzymes are involved in the resistance mechanism of transgenic rice. The transgenic rice line M4 was about >200-fold more resistant to oxyfluorfen than the wild-type (WT). M4 was also resistant to acifluorfen, carfentrazone-ethyl, and oxadiazon, but did not show multiple resistance to imazapyr and paraquat, which have different target sites. Acifluorfen, oxyfluorfen, carfentrazone-ethyl, and oxadiazon reduced the chlorophyll content in leaves of WT, but had minimal or no effect on M4. The...

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In this article, a continuous stabilization process was used to make flame resistant fibers from polyacrylonitrile (PAN) fibers. The effect of the stabilization time and the stretching process during the stabilization process on the physical properties and flammability of the resultant flame resistant fibers was studied. Increased drawing of PAN fibers during the continuous stabilization process was found to decrease the diameter and increase the tensile strength in the resultant flame resistant fibers. These fibers also had higher density. There were no absolute relationships seen between flame-resistance and the formation of stable ladder polymers, density, and oxygen content. ((orig.))

International Nuclear Information System (INIS)

Corrosion testings of model alloys, corresponding by chemical composition to simple and complex-alloyed #gamma#- and #gamma#'-phases of nickel heat-resistant alloys are conducted in sodium sulfate and chloride melts. It is ascertained that heat resistant nickel alloys containing over 50 % of hardening #gamma#'-phase, are subject to disastrous sulfide corrosion (SC). Resistance against SC alloys containing below 50 % of #gamma#'-phase is determined by the resistance of #gamma#-solid solution. 10 refs., 3 figs., 2 tabs.

UK PubMed Central (United Kingdom)

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

Science.gov (United States)

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

UK PubMed Central (United Kingdom)

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

Science.gov (United States)

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 ...

UK PubMed Central (United Kingdom)

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

DEFF Research Database (Denmark)

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.

UK PubMed Central (United Kingdom)

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

International Nuclear Information System (INIS)

The direct injection of steam into a water pool is a method of heat transfer used in many process industries. The amount of research in this area however is limited to the nuclear industry, with applications relating to reactor cooling systems. Electrical resistance tomography (ERT), a low cost, non-invasive and which has high temporal resolution characteristics, can be used as a visualization tool for the resistivity distribution for the steam injection into water pool such as IRWST. In this paper, three dimensional resistivity distribution of the process is obtained through ERT using iterative Gauss-Newton method. Numerical experiments are performed by assuming different resistive objects in the water pool. Numerical results show that ERT is successful in estimating the resistivity distribution for the injection of steam in the water pool

British Library Electronic Table of Contents (United Kingdom)

BACKGROUND: Glyphosate resistance has been confirmed in 58 populations of Lolium rigidum (Gaud.), a major weed of crops in southern Australia. Extensive use of glyphosate in conjunction with minimal soil disturbance has been identified as high risk for resistance to that herbicide. Land managers need a simple method for rapid assessment of the risk of resistance occurring as a result of past and proposed future management practices. Modelled on risk assessment nomographs, a simple calculator for indicating the risk of evolved glyphosate resistance in L. rigidum is described.RESULTS: The calculator uses the generations since first use and the frequency of use of glyphosate in combination with historical cultivation levels as critical factors for determining the risk of glyphosate resistance...

Energy Technology Data Exchange (ETDEWEB)

To make the surface composites with hard ceramics particles is an effective means for satisfying the request for the wear-resistance of the casting products. Covering casting is a general method for forming the composites by adding the adhesive into ceramics particles. However, due to the using of adhesive, pore and intermediate are easy to generate, and it is one of the reasons making the wear-resistance unstable. In the present study, it is attempted to form the wear-resistant composite layer by dispersing cast tungsten carbide (CTC) particles on the surface of wear-resistant 7 mass% Mn steel without using adhesives. Subsequently, the experiments on the wear-resistance of the obtained surface composites under several wear conditions are carried out. It is revealed by the results thereof that 7 mass% Mn steel surface composites with CTC particles have the ...

UK PubMed Central (United Kingdom)

HIV-1 nonsubtype B variants account for the majority of HIV infections worldwide. Drug resistance in individuals who have never undergone antiretroviral therapy can lead to early failure and...Full Text Available

Science.gov (United States)

Sugarcane rusts, brown (caused by Puccinia melanocephala) and orange (caused by P. kuehnii), are agronomically important diseases in Florida. Cultivar resistance is the best means of managing these diseases. Unfortunately, natural infection of brown rust is not always efficient in determining resist...

UK PubMed Central (United Kingdom)

The resistance to destruction of spores of Bacillus subtilis var. niger occluded in crystals of calcium carbonate and exposed to ethylene oxide and moist and dry heat...Full Text Available

UK PubMed Central (United Kingdom)

We have evaluated the performance of two rapid, low-cost methods for the detection of ofloxacin (OFX) resistance with 95 Mycobacterium tuberculosis isolates from countries with high...Full Text Available

UK PubMed Central (United Kingdom)

The evolution of drug resistant bacteria is a severe public health problem, both in hospitals and in the community. Currently, some countries aim at concentrating highly specialized services in large...Full Text Available

UK PubMed Central (United Kingdom)

A 42% (70 of 167 isolates) incidence of resistance to 20 micrograms of trimethoprim per ml was found among clinical isolates of coagulase-negative staphylococci from two hospitals. A specific trimethoprim...Full Text Available

UK PubMed Central (United Kingdom)

Purpose:Methicillin-resistant Staphylococcus aureus (MRSA) strains are commonly classified as hospital-acquired (HA) or community-acquired (CA). Typical HA-MRSA...Full Text Available

UK PubMed Central (United Kingdom)

Tetracycline-resistant Lactococcus lactis strains originally isolated from Polish raw milk were analyzed for the ability to transfer their antibiotic resistance genes in vitro, using...Full Text Available

UK PubMed Central (United Kingdom)

Juvenile hormone analog (JHA) insecticides are relatively nontoxic to vertebrates and offer effective control of certain insect pests. Recent reports of resistance in whiteflies and mosquitoes demonstrate...Full Text Available

UK PubMed Central (United Kingdom)

Insulin resistance in skeletal muscle is a key phenotype associated with type 2 diabetes (T2D) for which the molecular mediators remain unclear. We therefore conducted an expression analysis of human...Full Text Available

UK PubMed Central (United Kingdom)

Extended-spectrum beta-lactamases (ESBL) constitute a key antibiotic-resistance mechanism affecting Gram-negative bacteria, and also an excellent model for studying evolution in real time. A shift in...Full Text Available

UK PubMed Central (United Kingdom)

We compared MRSA Select to mannitol-salt agar with 8 μg/ml cefoxitin for the detection of methicillin-resistant Staphylococcus aureus (MRSA) from 6,199 clinical...Full Text Available

UK PubMed Central (United Kingdom)

Denaturing high-performance liquid chromatography (DHPLC) has been used extensively to detect genetic variation. We used this method to detect and identify Yersinia pestis KIM5 ciprofloxacin-resistant...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundThe emergence of plasmid-mediated carbapenemases, such as NDM-1 in Enterobacteriaceae is a major public health issue. Since they mediate resistance to...Full Text Available

UK PubMed Central (United Kingdom)

Objective:To estimate the prevalence of insulin resistant syndrome (IRS) among newly diagnosed patients with type 2 diabetes and to test their validity against two indices...Full Text Available

Science.gov (United States)

... Axial Waterjet (AxWJ) Model 5662: 0 Hull Resistance and Model-Scale Powering C with LDV Nozzle Design CO By C ClC ...

UK PubMed Central (United Kingdom)

BackgroundMany commercial banana varieties lack sources of resistance to pests and diseases, as a consequence of sterility and narrow genetic background. Fertile wild relatives,...Full Text Available

UK PubMed Central (United Kingdom)

Acquired resistance to the action of insulin to stimulate glucose transport in skeletal muscle is associated with obesity and promotes the development of type 2 diabetes. In skeletal muscle,...Full Text Available

UK PubMed Central (United Kingdom)

Reciprocal mass crosses and back-crosses were performed between two homogeneous strains of the housefly (Musca domestica L.), representing the extremes in susceptibility and resistance...Full Text Available

UK PubMed Central (United Kingdom)

BackgroundInsecticide-based methods represent the most effective means of blocking the transmission of vector borne diseases. However, insecticide resistance poses a serious threat...Full Text Available

Energy Technology Data Exchange (ETDEWEB)

Laser surface alloying with gaseous nitrogen was utilized to improve the wear resistance of a Ti-6Al-4V alloy. Wear-resistant composite coatings reinforced by hard TiN dendrites were produced 'in-situ' on a substrate of a Ti-6Al-4V alloy. The hardness and wear resistance of the laser alloyed coating under two-body abrasive and block-on-ring full-sliding wear conditions were significantly enhanced. (orig.)

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... The micrometeorological community often expresses these relations in resistance law terms (Garratt and Hicks, 1973; Hicks et al., 1985) ...

International Nuclear Information System (INIS)

17-4PH stainless steel was modified by direct current (DC) plasma nitriding and titanium nitride film duplex treatment in this study. The microstructure, wear resistance and corrosion resistance were characterized by X-ray diffraction (XRD), pin-on-disk tribological test and polarization experiment. The results revealed that the DC plasma nitriding pretreatment was in favor of improving properties of titanium nitride film. The corrosion resistance and wear resistance of duplex treatment specimen was more superior to that of only coated titanium nitride film.

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... Abstract : Two traces in flexible cables used in the Milstar agile beam antenna system failed during acceptance testing. ...

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PMID:17346598

Science.gov (United States)

increase of pedel force; or amount of resistance to deflection. This result is in agreement wi"& the results of tests made on the ...

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Not Available

Energy Technology Data Exchange (ETDEWEB)

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).

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... The maximum rate-of-deflection is not&d to decresse with increase of pedel force; or amount of resistance to deflection. ...

Energy Technology Data Exchange (ETDEWEB)

Resistance of ALLOY 800 as a PWR/SG tubings to IGC/IGSCC and Ni, Co release into high temperature water was evaluated as compared with ALLOYs 600 and 690. The study to improve the resistance to IGSCC and general corrosion was also made. From the results, ALLOY 800 was evaluated to be the most reliable among the high Ni alloys tested. In addition, the alloy would obtain further reliability in IGSCC and general corrosion resistance by the combined addition of Ti and Nb, and the prior oxidation treatments, respectively. (author).

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... populations ..... 63 34 Vertebral ultimate compressive strength for various populations ..... 64 35 ...

Science.gov (United States)

... HIGH FREQUENCY, WIRE, ATMOSPHERIC MOTION, SENSITIVITY, PLATINUM, FREQUENCY RESPONSE, AMPLIFIERS, MULTIVIBRATORS. ...

Environmental Research Database

DescriptionThis project investigates in silico the interactive consequences of breeding for parasite resistance and nutritional environment on livestock productivity. The thesis of the work is that conflicting evidence regarding the consequences of breeding for parasite resistance arises from the failure to consider the interactions between host genetics and nutritional environment. Starting with a framework that accounts for the consequences of host nutrition on the development of parasitism, we will (1 [continued...

Science.gov (United States)

Biofilm-specific antibiotic resistance is influenced by multiple factors. We demonstrated that Pseudomonas aeruginosa tssC1, a gene implicated in type VI secretion (T6S), is important for resistance of biofilms to a subset of antibiotics. We showed that tssC1 expression is induced in biofilms and confirmed that tssC1 is required for T6S. PMID:21784934

Science.gov (United States)

Resistance exercise has been widely reported to have positive rehabilitation effects for patients with neuromuscular and orthopaedic conditions. This paper presents an optimal design of magneto-rheological fluid dampers for variable resistance exercise devices. Adaptive controls for regulating the resistive force or torque of the device as well as the joint motion are presented. The device provides both isometric and isokinetic strength training for various human joints.

Energy Technology Data Exchange (ETDEWEB)

The electrical resistivity at low temperatures (T = 10 to 90 K) of the lithium isotopes /sup 6/Li and /sup 7/Li and of an isotopic mixture /sup 7 +6/Li has been studied. The specimens contained a small amount of chemical impurities. An appreciable difference was observed in the temperature dependence of the resistivity produced both by deformation of the phonon spectrum, related to the change in isotopic composition, and by the presence of chemical impurities making the nonequilibrium part of the electron distribution function more isotropic.

Energy Technology Data Exchange (ETDEWEB)

The method of the present invention comprises a step of previously coating a positive type resist on the surface of equipment, a step of solidifying the coated positive type resist and a step of bringing the coated equipment to circumstances for use and cleaning the positive type resist. With such procedures, the amount of radioactive materials deposited on the equipment can be reduced, and redeposition of nuclides on the surface to be cleaned can be prevented. (T.M.)

Science.gov (United States)

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 ...

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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 ...

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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.

International Nuclear Information System (INIS)

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).

Energy Technology Data Exchange (ETDEWEB)

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)

International Nuclear Information System (INIS)

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).

Science.gov (United States)

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 ...

Energy Technology Data Exchange (ETDEWEB)

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 ...

British Library Electronic Table of Contents (United Kingdom)

This paper presents the first report of multiple anthelmintic resistance in the gastrointestinal nematodes of goats and its possible contributory factors in an irrigated area (Pakistan). A total of 18 privately owned Beetal goat flocks were selected in order to determine the anthelmintic resistance against commonly used anthelmintics. Forty to 48 animals from each flock were selected according to their weight and egg count. The three anthelmintics viz., oxfendazole, levamisole and ivermectin, were given to three groups at manufacturer's recommended dose while one group was kept as untreated control. Anthelmintic resistance was determined through faecal egg count reduction and egg hatch tests while assessment of the contributory factors of anthelmintic resistance was measured through the ru...

British Library Electronic Table of Contents (United Kingdom)

This study compares two series of solvents for application in aluminum electrolytic capacitors: ethylene glycol (EG) and water mixtures, and ethylene glycol and 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4) ionic liquid (IL) mixtures. Electrochemical impedance spectroscopy and cyclic voltammetry were carried out with a previously anodized aluminum disk electrode. Comparative measurements of solution resistance, polarization resistance, AC capacitance, and passive current were made. The results show that EG?IL mixtures with low amounts of IL (10% IL?90% EG v/v) have a low solution resistance. Low values of solution resistance, high values of polarization resistance, small passive current, and uniform capacitance of anodized aluminum in EG?IL mixtures are favorable properties of ...

International Nuclear Information System (INIS)

The effect of phosphorus on the corrosion resistance of Al-bronzes is studied in detail in this work. A literature review showed that there are a lot of things known about the microstructure and the mechanical properties of Al-bronzes. In spite of their corrosion resistance the corrosion properties and the structure of the protective oxide films of Al-bronzes were seldom a matter of interest. Systematic studies of the influence of different alloying elements on the oxide film and the corrosion properties are rare. Therefore, it is not possible to predict the corrosion resistance of Al-bronzes, made by alloying particular elements. The high corrosion resistance of the new alloy CuAl_2_0P_1 was the reason to investigate the influence of phosphorus on the corrosion properties of Al-bronzes in more detail. A systematic study of the microstructure and the corrosion properties of Cu, CuP_x, CuAl_2_0 and ...

Energy Technology Data Exchange (ETDEWEB)

A comparison of the loss mechanisms in screen-printed solar cells relative to buried contact cells and cells with photolithography-defined contacts is presented in this paper. Model calculations show that emitter recombination accounts for about 0.5% absolute efficiency loss in conventional screen-printed cells with low-sheet-resistance emitters. Ohmic contact to high-sheet-resistance emitters by screen-printing has been investigated to regain this efficiency loss. Our work shows that good quality ohmic contacts to high sheet-resistance emitters can be achieved if the glass frit chemistry and Ag particle size are carefully tailored. The melting characteristics of the glass frit determine the firing scheme suitable for low contact resistance and high fill factors. In addition, small to regular Ag particles were found to help achieve a higher open-circuit voltage and maintain a low contact ...

International Nuclear Information System (INIS)

The corrosion resistance of zircaloy is affected by conditions of heat treatment in the manufacturing steps to be formed into a final product as a structural material. In the manufacturing method of the present invention, a Zr alloy controlled to contain Sn: 0.8 to 1.2wt%, Fe: 0.17 to 0.28wt%, Cr: 0.05 to 0.15wt%, Ni: 0.04 to 0.10wt%, Nb: 0.01 to 0.09wt%, oxygen: 1,000 to 1,500ppm and Si, an Si impurity at a concentration of 120ppm or less and balance of Zr is melted into a cast piece, to which #beta# hardening is applied. Then, rolling and annealing treatment are applied so that the total heat input amount to the material: #SIGMA#Ai ranges from 1 x 10"-"1"9 to 1 x 10"-"1"7. With such procedures, a Zr alloy structural material for a reactor core having excellent homogeneous corrosion resistance and hydrogen absorption resistance for a long period of time while having a sufficient strength can be obtained even in a case ...

Energy Technology Data Exchange (ETDEWEB)

In response to a heat shock, the yeast Saccharomyces cerevisiae undergoes a large increase in its resistance to heat and, by the induction of its recombinational DNA repair capacity, a corresponding increase in resistance to radiation. Yeast which lack mitochondrial DNA, mitochondria-controlled protein synthetic apparatus, aerobic respiration, and electron transport (rho/sup 0/ strain) were used to assess the role of O/sub 2/, mitochondria, and oxidative processes controlled by mitochondria in the induction of these resistances. We have found that rho/sup 0/ yeast grown and heat shocked in either the presence or absence of O/sub 2/ are capable of developing both radiation and heat resistance. We conclude that neither the stress signal nor its cellular consequences of induced heat and radiation resistance are directly dependent on O/sub 2/, mitochondrial DNA, or ...

Science.gov (United States)

A discussion of some of the difficulties with previous analyses of the resistivity of A-15 compounds is given. Precise high-temperature data on ..cap alpha..-particle- and electron-damaged Nb/sub 3/Ge and Nb/sub 3/Sn samples with different defect concentrations are presented here and analyzed in a simple way with use of a phenomenological model based on the idea that the ideal resistivity must approach some limiting value in the regime where the mean free path becomes comparable to the interatomic spacing.

Energy Technology Data Exchange (ETDEWEB)

The resistance of six tropical hardwoods to fungal degradation by two wild-type strains of Phanerochaete chrysosporium Burdsall was investigated using vermiculite burial and wood-block weight loss techniques. Radiation-induced wood-polymer composites (WPC), based on two hardwoods Ramin and Rubberwood with methyl methacrylate, were prepared, and samples were also exposed to the wood-rotting fungus. A significant improvement in resistance to fungal decay was observed in the WPC. Scanning-electron micrographs of the two woods and their composites after fungal degradation are presented and discussed.

Energy Technology Data Exchange (ETDEWEB)

The damage induced by low-temperature proton irradiation in amorphous Pd/sub 80/Si/sub 20/ prepared by ion implantation is studied via electrical resistivity measurements. Our experimental results concerning the initial damage rate and the resistivity saturation are compared to the results obtained for electron and high energy /sup 16/O irradiation of amorphous Pd/sub 80/Si/sub 20/ quenched from the melt. The resistivity curve is analyzed in terms of irradiation-induced point defects.

British Library Electronic Table of Contents (United Kingdom)

Resistance and tolerance are two types of host defense mechanisms that increase fitness in response to fungi. Several genetic polymorphisms in pattern recognition receptors, most remarkably Toll-like receptors (TLRs), have been described to influence resistance and tolerance to aspergillosis in distinct clinical settings. TLRs on dendritic cells pivotally contribute in determining the balance between immunopathology and protective immunity to the fungus. Epithelial cells also contribute to this balance via selected TLRs converging on indoleamine-2,3-dioxygenase (IDO). Studies in experimental hematopoietic transplantation confirmed the dichotomy of pathways leading to resistance and tolerance to the fungus providing new insights on the relative contribution of the hematopoietic/nonhematopoi...

British Library Electronic Table of Contents (United Kingdom)

Glabridin, an active constituent of Glycyrrhiza glabra roots, was found to be active against both yeast and filamentous fungi. Glabridin also showed resistance modifying activity against drug resistant mutants of Candida albicans at a minimum inhibitory concentration of 31.25-250 g/mL. Although the compound was reported earlier to be active against Candida albicans, but this is the first report of its activity against drug resistant mutants. Copyright Copyright 2009 John Wiley & Sons, Ltd.

Energy Technology Data Exchange (ETDEWEB)

This report presents a brief description of the fabrication and advantages of a composite, carbon-metal fiber material which does not require lubrication.

International Nuclear Information System (INIS)

A series of hydrogenation/dehydrogenation cycles have been performed on palladium wire samples, stressed by a constant mechanical tension, in order to investigate the changes in electrical and mechanical properties. A large increase of palladium electrical resistivity has been reported due to the combined effects of the production of defects linked to hydrogen insertion into the host lattice and the stress applied to the sample. An increase of the palladium sample strain due to hydrogenation/dehydrogenation cycles in ????? phase transitions is observed compared to the sample subjected to mechanical tension only. The loss of initial metallurgical properties of the sample occurs already after the first hydrogen cycle, i.e. a displacement from the initial metallic behavior (increase of the resistivity and decrease of thermal coefficient of resistivity) to a worse one occurs already after the first hydrogen cycle. A linear ...

International Nuclear Information System (INIS)

Ceramic fuel element is one of the most important items of HTGR technology, and the corrosion resistance of is matrix materials is vital to the operational performance of HTGR. In the paper, based on the oxidation study of the matrix materials, it has been proposed that the corrosion resistance of the matrix materials might be improved through forming carbon -ceramic composite. The experiment results have shown that the corrosion resistance of matrix materials has been improved by addition of SiC superfine powders, and that the matrix materials containing SiC superfine powders and heat-treated at 1600 deg. C had an oxidation rate lower than the general one containing no SiC superfine powder and heat-treated at 1950 deg. C. (author). 5 refs, 8 figs.

International Nuclear Information System (INIS)

The electrical resistivity, Hall effect, and magnetic susceptibility of single-crystal UPd_2Si_2 have been studied between 4.2 and 300 K. A large anisotropy was observed in both the magnetic and transport properties. There is a quadratic temperature dependence of the resistivity for a range of temperatures between 4.2 and 80 K. At higher temperatures, the resistivity indicates a Kondo-type behavior. The behavior of these quantities is accounted for by the magnetic phase transitions at 108 and 136 K reported from neutron-scattering studies. At high temperatures, the magnetic susceptibility of UPd_2Si_2 is Curie-Wiess-like along the c axis. The temperature dependence of the Hall coefficient above 108 K is accounted for by a theoretical model invoking skew scattering of conduction electrons by localized magnetic moments.

Science.gov (United States)

... B. P. Rosen. An arsenic metallochaperone for an arsenic detoxification pump. Proc. Natl. Acad. Sci. U. S. A 103( ... ...

British Library Electronic Table of Contents (United Kingdom)

The regenerative-chatter resistance of a viscoelastic cantilever beam is analyzed and compared to the common dynamic vibration absorber (DVA) system. The beam represents a tool holder for turning operation in machining. The optimum structural parameters are found by maximizing the most negative real part of the frequency response function (FRF). The FRF is found analytically by using an appropriate Greens function. Keeping the cantilever static stiffness constant, further increase in the optimal resistance is achieved by changing the ratio between the two elastic moduli in the 3-parameter solid viscoelastic material model. Three additional chatter resistance indicators are also investigated: the most positive real part of the FRF, the magnitude of the FRF and the resonant frequency. It is ...