Sample records for hepatic forms mat
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Aspects of the ecology of mat-forming lichens
Directory of Open Access Journals (Sweden)
P. D. Crittenden
2000-03-01
Full Text Available Lichen species in the genera Cladonia (subgenus Cladina, Cetraria, Stereocaulon and Alectoria are important vegetation components on well-drained terrain and on elevated micro-sites in peatlands in boreal-Arctic regions. These lichens often form closed mats, the component thalli in which grow vertically upwards at the apices and die off in the older basal regions; they are therefore only loosely attached to the underlying soil. This growth habit is relatively unusual in lichens being found in <0.5% of known species. It might facilitate internal nutrienr recycling and higher growth rates and, together with the production of allelochemicals, it might underlie the considerable ecological success of mat-forming lichens; experiments to critically assess the importance of these processes are required. Mat-forming lichens can constitute in excess of 60% of the winter food intake of caribou and reindeer. Accordingly there is a pressing need for data on lichen growth rates, measured as mass increment, in order to help determine the carrying capacity of winter ranges for rhese herbivores and to better predict recovery rates following grazing. Trampling during the snow-free season fragments lichen thalli; mat-forming lichens regenerate very successfully from thallus fragments provided trampling does nor re-occur. Frequent recurrence of trampling creates disturbed habitats from which lichens will rapidly become eliminated consistent with J.P. Grime's CSR strategy theory. Such damage to lichen ground cover has occurred where reindeer or caribou are unable to migrate away from their winter range such as on small islands or where political boundaries have been fenced; it can also occur on summer range that contains a significant lichen component and on winter range where numbers of migrarory animals become excessive. Species of Stereocaulon, and other genera that contain cyanobacteria (most notably Peltigera and Nephroma, are among the principal agents of
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Laurel A. Kluber; Jane E. Smith; David D. Myrold
2011-01-01
The distinct rhizomorphic mats formed by ectomycorrhizal Piloderma fungi are common features of the organic soil horizons of coniferous forests of the Pacific Northwest. These mats have been found to cover 25-40% of the forest floor in some Douglas-fir stands, and are associated with physical and biochemical properties that distinguish them from...
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International Nuclear Information System (INIS)
Brown, J. Michael; Ball, John G.; Hogsett, Amy; Williams, Tierra; Valentovic, Monica
2010-01-01
Acetaminophen (APAP) is the leading cause of drug induced liver failure in the United States. Previous studies in our laboratory have shown that S-adenosyl methionine (SAMe) is protective for APAP hepatic toxicity. SAMe is critical for glutathione synthesis and transmethylation of nucleic acids, proteins and phospholipids which would facilitate recovery from APAP toxicity. SAMe is synthesized in cells through the action of methionine adenosyltransferase (MAT). This study tested the hypothesis that total hepatic and subcellular SAMe levels are decreased by APAP toxicity. Studies further examined MAT expression and activity in response to APAP toxicity. Male C57BL/6 mice (16-22 g) were treated with vehicle (Veh; water 15 ml/kg ip injections), 250 mg/kg APAP (15 ml/kg, ip), SAMe (1.25 mmol/kg) or SAMe administered 1 h after APAP injection (SAMe and SAMe + APAP). Hepatic tissue was collected 2, 4, and 6 h after APAP administration. Levels of SAMe and its metabolite S-adenosylhomocysteine (SAH) were determined by HPLC analysis. MAT expression was examined by Western blot. MAT activity was determined by fluorescence assay. Total liver SAMe levels were depressed at 4 h by APAP overdose, but not at 2 or 6 h. APAP depressed mitochondrial SAMe levels at 4 and 6 h relative to the Veh group. In the nucleus, levels of SAMe were depressed below detectable limits 4 h following APAP administration. SAMe administration following APAP (SAMe + APAP) prevented APAP associated decline in mitochondrial and nuclear SAMe levels. In conclusion, the maintenance of SAMe may provide benefit in preventing damage associated with APAP toxicity.
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Hauri, Claudine; Fabricius, Katharina E; Schaffelke, Britta; Humphrey, Craig
2010-09-13
Disturbed coral reefs are often dominated by dense mat- or canopy-forming assemblages of macroalgae. This study investigated how such dense macroalgal assemblages change the chemical and physical microenvironment for understorey corals, and how the altered environmental conditions affect the physiological performance of corals. Field measurements were conducted on macroalgal-dominated inshore reefs in the Great Barrier Reef in quadrats with macroalgal biomass ranging from 235 to 1029 g DW m(-2) dry weight. Underneath mat-forming assemblages, the mean concentration of dissolved oxygen was reduced by 26% and irradiance by 96% compared with conditions above the mat, while concentrations of dissolved organic carbon and soluble reactive phosphorous increased by 26% and 267%, respectively. The difference was significant but less pronounced under canopy-forming assemblages. Dissolved oxygen declined and dissolved inorganic carbon and alkalinity increased with increasing algal biomass underneath mat-forming but not under canopy-forming assemblages. The responses of corals to conditions similar to those found underneath algal assemblages were investigated in an aquarium experiment. Coral nubbins of the species Acropora millepora showed reduced photosynthetic yields and increased RNA/DNA ratios when exposed to conditions simulating those underneath assemblages (pre-incubating seawater with macroalgae, and shading). The magnitude of these stress responses increased with increasing proportion of pre-incubated algal water. Our study shows that mat-forming and, to a lesser extent, canopy-forming macroalgal assemblages alter the physical and chemical microenvironment sufficiently to directly and detrimentally affect the metabolism of corals, potentially impeding reef recovery from algal to coral-dominated states after disturbance. Macroalgal dominance on coral reefs therefore simultaneously represents a consequence and cause of coral reef degradation.
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Directory of Open Access Journals (Sweden)
Claudine Hauri
2010-09-01
Full Text Available Disturbed coral reefs are often dominated by dense mat- or canopy-forming assemblages of macroalgae. This study investigated how such dense macroalgal assemblages change the chemical and physical microenvironment for understorey corals, and how the altered environmental conditions affect the physiological performance of corals. Field measurements were conducted on macroalgal-dominated inshore reefs in the Great Barrier Reef in quadrats with macroalgal biomass ranging from 235 to 1029 g DW m(-2 dry weight. Underneath mat-forming assemblages, the mean concentration of dissolved oxygen was reduced by 26% and irradiance by 96% compared with conditions above the mat, while concentrations of dissolved organic carbon and soluble reactive phosphorous increased by 26% and 267%, respectively. The difference was significant but less pronounced under canopy-forming assemblages. Dissolved oxygen declined and dissolved inorganic carbon and alkalinity increased with increasing algal biomass underneath mat-forming but not under canopy-forming assemblages. The responses of corals to conditions similar to those found underneath algal assemblages were investigated in an aquarium experiment. Coral nubbins of the species Acropora millepora showed reduced photosynthetic yields and increased RNA/DNA ratios when exposed to conditions simulating those underneath assemblages (pre-incubating seawater with macroalgae, and shading. The magnitude of these stress responses increased with increasing proportion of pre-incubated algal water. Our study shows that mat-forming and, to a lesser extent, canopy-forming macroalgal assemblages alter the physical and chemical microenvironment sufficiently to directly and detrimentally affect the metabolism of corals, potentially impeding reef recovery from algal to coral-dominated states after disturbance. Macroalgal dominance on coral reefs therefore simultaneously represents a consequence and cause of coral reef degradation.
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Directory of Open Access Journals (Sweden)
James M. Trappe
2012-04-01
Full Text Available In forest ecosystems, fungal mats are functionally important in nutrient and water uptake in litter and wood decomposition processes, in carbon resource allocation, soil weathering and in cycling of soil resources. Fungal mats can occur abundantly in forests and are widely distributed globally. We sampled ponderosa pine/white fir and mountain hemlock/noble fir communities at Crater Lake National Park for mat-forming soil fungi. Fungus collections were identified by DNA sequencing. Thirty-eight mat-forming genotypes were identified; members of the five most common genera (Gautieria, Lepiota, Piloderma, Ramaria, and Rhizopogon comprised 67% of all collections. The mycorrhizal genera Alpova and Lactarius are newly identified as ectomycorrhizal mat-forming taxa, as are the saprotrophic genera Flavoscypha, Gastropila, Lepiota and Xenasmatella. Twelve typical mat forms are illustrated, representing both ectomycorrhizal and saprotrophic fungi that were found. Abundance of fungal mats was correlated with higher soil carbon to nitrogen ratios, fine woody debris and needle litter mass in both forest ecotypes. Definitions of fungal mats are discussed, along with some of the challenges in defining what comprises a fungal “mat”.
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Strain, Elisabeth M A; Thomson, Russell J; Micheli, Fiorenza; Mancuso, Francesco P; Airoldi, Laura
2014-11-01
Identifying the type and strength of interactions between local anthropogenic and other stressors can help to set achievable management targets for degraded marine ecosystems and support their resilience by identifying local actions. We undertook a meta-analysis, using data from 118 studies to test the hypothesis that ongoing global declines in the dominant habitat along temperate rocky coastlines, forests of canopy-forming algae and/or their replacement by mat-forming algae are driven by the nonadditive interactions between local anthropogenic stressors that can be addressed through management actions (fishing, heavy metal pollution, nutrient enrichment and high sediment loads) and other stressors (presence of competitors or grazers, removal of canopy algae, limiting or excessive light, low or high salinity, increasing temperature, high wave exposure and high UV or CO2 ), not as easily amenable to management actions. In general, the cumulative effects of local anthropogenic and other stressors had negative effects on the growth and survival of canopy-forming algae. Conversely, the growth or survival of mat-forming algae was either unaffected or significantly enhanced by the same pairs of stressors. Contrary to our predictions, the majority of interactions between stressors were additive. There were however synergistic interactions between nutrient enrichment and heavy metals, the presence of competitors, low light and increasing temperature, leading to amplified negative effects on canopy-forming algae. There were also synergistic interactions between nutrient enrichment and increasing CO2 and temperature leading to amplified positive effects on mat-forming algae. Our review of the current literature shows that management of nutrient levels, rather than fishing, heavy metal pollution or high sediment loads, would provide the greatest opportunity for preventing the shift from canopy to mat-forming algae, particularly in enclosed bays or estuaries because of the
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Ectomycorrhizal mats alter forest soil biogeochemistry
Laurel A. Kluber; Kathryn M. Tinnesand; Bruce A. Caldwell; Susie M. Dunham; Rockie R. Yarwood; Peter J. Bottomley; David D. Myrold
2010-01-01
Dense hyphal mats formed by ectomycorrhizal (EcM) fungi are prominent features in Douglas-fir forest ecosystems, and have been estimated to cover up to 40% of the soil surface in some forest stands. Two morphotypes of EcM mats have been previously described: rhizomorphic mats, which have thick hyphal rhizomorphs and are found primarily in the organic horizon, and...
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Foam-mat drying technology: A review.
Hardy, Z; Jideani, V A
2017-08-13
This article reviews various aspects of foam-mat drying such as foam-mat drying processing technique, main additives used for foam-mat drying, foam-mat drying of liquid and solid foods, quality characteristics of foam-mat dried foods, and economic and technical benefits for employing foam-mat drying. Foam-mat drying process is an alternative method that allows the removal of water from liquid materials and pureed materials. In this drying process, a liquid material is converted into foam that is stable by being whipped after adding an edible foaming agent. The stable foam is then spread out in sheet or mat and dried by using hot air (40-90°C) at atmospheric pressure. Methyl cellulose (0.25-2%), egg white (3-20%), maltodextrin (0.5-05%), and gum Arabic (2-9%) are the commonly utilized additives for the foam-mat drying process at the given range, either combined together for their effectiveness or individual effect. The foam-mat drying process is suitable for heat sensitive, viscous, and sticky products that cannot be dried using other forms of drying methods such as spray drying because of the state of product. More interest has developed for foam-mat drying because of the simplicity, cost effectiveness, high speed drying, and improved product quality it provides.
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Contributions of Ectomycorrhizal Fungal Mats to Forest Soil Carbon Cycles
Kluber, L. A.; Phillips, C. L.; Myrold, D. D.; Bond, B. J.
2008-12-01
Ectomycorrhizal (EM) fungi are a prominent and ubiquitous feature of forest soils, forming symbioses with most tree species, yet little is known about the magnitude of their impact on forest carbon cycles. A subset of EM fungi form dense, perennial aggregations of hyphae, which have elevated respiration rates compared with neighboring non-mat soils. These mats are a foci of EM activity and thereby a natural laboratory for examining how EM fungi impact forest soils. In order to constrain the contributions of EM fungi to forest soil respiration, we quantified the proportion of respiration derived from EM mat soils in an old-growth Douglas-fir stand in western Oregon. One dominant genus of mat-forming fungi, Piloderma, covered 56% of the soil surface area. Piloderma mats were monitored for respiration rates over 15 months and found to have on average 10% higher respiration than non-mat soil. At the stand level, this amounts to roughly 6% of soil respiration due to the presence of Piloderma mats. We calculate that these mats may constitute 27% of autotrophic respiration, based on respiration rates from trenched plots in a neighboring forest stand. Furthermore, enzyme activity and microbial community profiles in mat and non-mat soil provide evidence that specialized communities utilizing chitin contribute to this increased efflux. With 60% higher chitinase activity in mats, the breakdown of chitin is likely an important carbon flux while providing carbon and nitrogen to the microbial communities associated with mats. Quantitative PCR showed similar populations of fungi and bacteria in mat and non-mat soils; however, community analysis revealed distinct fungal and bacterial communities in the two soil types. The higher respiration associated with EM mats does not appear to be due only to a proliferation of EM fungi, but to a shift in overall community composition to organisms that efficiently utilize the unique resources available within the mat, including plant and
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Aranda, Carlos; Paredes, Javier; Valenzuela, Cristian; Lam, Phyllis; Guillou, Laure
2010-01-01
The mat forming bacteria covering organic matter-enriched and anoxic marine sediments underlying a salmon farm in Southern Chile, were examined using 16S rRNA gene phylogenies. This mat was absent in the sea bed outside the direct influence of the farm (360 m outside fish cages). Based on nearly complete 16S rRNA gene sequences (-1500 bp), mat-forming filamentous cells were settled as the sulphur-oxidizing and putatively dissimilative nitrate-reducing Beggiatoa spp., being closely related (up...
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Cullis, J. D.; Gillis, C.; Bothwell, M.; Kilroy, C.; Packman, A. I.; Hassan, M. A.
2010-12-01
The nuisance diatom Didymosphenia geminata (didymo) presents an ecological paradox. How can this benthic algae produce such large amounts of biomass in cold, fast flowing, low nutrient streams? The aim of this paper is to present a conceptual model for the growth, persistence, and blooming behavior of this benthic mat-forming diatom that may help to explain this paradox. The conceptual model highlights the importance of distinguishing between mat thickness and cell growth. It presents evidence gathered from a range of existing studies around the world to support the proposed relationship between growth and light, nutrients and temperature as well as the importance of flood events and bed disturbance in mat removal. It is anticipated that this conceptual model will not only help in identifying the key controlling variables and set a framework for future studies but also support the future management of this nuisance algae. Summary of the conceptual model for didymo growth showing the proposed relationships for the growth of cells and mats with nutrients, radiation and water temperature and the dependence of removal on bed shear stress and the potential for physical bed disturbance.
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MAT FOR LEPTOSPIROSIS DIAGNOSIS
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Esti Rahardianingtyas.
2014-06-01
Full Text Available Leptospirosis is a disease caused by bacterial infection leptospira interrogans.Leptospira bacteria is a spiral bacterium with solid strands with two flagella periplasmik.Septicaemic phase patient samples taken from the blood and cerebrospinal fluid, whereassamples taken at phase immune extracted from urine. The diagnosis of leptospirosis occurdirectly or indirectly. Diagnosis is done by directly isolate and identify the causative agents ofthe agent. Diagnosis is done indirectly by detecting specific antibodies from the patient's body.Gold Standard of the diagnosis of leptospirosis is MAT. Mat made by reacting antibodies toleptospira antigen. Positive results seen with clump formed.Key words: Leptospirosis, Leptospirosis Diagnostic, MAT (Microscopic Agglutination Test Leptospirosis merupakan penyakit yang disebabkan karena infeksi bakteri leptospirainterrogans. Bakteri leptospira merupakan bakteri spiral dengan untaian yang padat dengan duaflagella periplasmik. Sampel pasien pada fase septicaemic diambil dari darah dan cairanserebrospinal, sedangkan sampel yang diambil pada fase immune diambil dari urine. Diagnosisleptospirosis dilakukan secara langsung maupun tidak langsung. Diagnosis secara langsungdilakukan dengan cara mengisolasi agen penyebab dan mengidentifikasi agen tersebut. Diagnosissecara tidak langsung dilakukan dengan cara mendeteksi antibodi spesiflk dari dalam tubuhpasien. Gold Standart dari diagnosis leptospirosis adalah MAT. Mat dilakukan dengan caramereaksikan antibodi dengan antigen leptospira. Hasil positif dilihat dengan terbentuk gumpalanagglutinasiKata kunci: Leptospirosis, Leptospira, Leptospirosis Diagnosis.
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Ionescu, D; Spitzer, S; Reimer, A; Schneider, D; Daniel, R; Reitner, J; de Beer, D; Arp, G
2015-03-01
Microbialite-forming microbial mats in a hypersaline lake on the atoll of Kiritimati were investigated with respect to microgradients, bulk water chemistry, and microbial community composition. O2, H2S, and pH microgradients show patterns as commonly observed for phototrophic mats with cyanobacteria-dominated primary production in upper layers, an intermediate purple layer with sulfide oxidation, and anaerobic bottom layers with sulfate reduction. Ca(2+) profiles, however, measured in daylight showed an increase of Ca(2+) with depth in the oxic zone, followed by a sharp decline and low concentrations in anaerobic mat layers. In contrast, dark measurements show a constant Ca(2+) concentration throughout the entire measured depth. This is explained by an oxygen-dependent heterotrophic decomposition of Ca(2+)-binding exopolymers. Strikingly, the daylight maximum in Ca(2+) and subsequent drop coincides with a major zone of aragonite and gypsum precipitation at the transition from the cyanobacterial layer to the purple sulfur bacterial layer. Therefore, we suggest that Ca(2+) binding exopolymers function as Ca(2+) shuttle by their passive downward transport through compression, triggering aragonite precipitation in the mats upon their aerobic microbial decomposition and secondary Ca(2+) release. This precipitation is mediated by phototrophic sulfide oxidizers whose action additionally leads to the precipitation of part of the available Ca(2+) as gypsum. © 2014 John Wiley & Sons Ltd.
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Nishizawa, Manabu; Koba, Keisuke; Makabe, Akiko; Yoshida, Naohiro; Kaneko, Masanori; Hirao, Shingo; Ishibashi, Jun-ichiro; Yamanaka, Toshiro; Shibuya, Takazo; Kikuchi, Tohru; Hirai, Miho; Miyazaki, Junichi; Nunoura, Takuro; Takai, Ken
2013-07-01
We report here the concurrence and interaction among forms of nitrogen metabolism in thermophilic microbial mat communities that developed in an ammonium-abundant subsurface geothermal stream. First, the physical and chemical conditions of the stream water at several representative microbial mat habitats (including upper, middle and downstream sites) were characterized. A thermodynamic calculation using these physical and chemical conditions predicted that nitrification consisting of ammonia and nitrite oxidations would provide one of the largest energy yields of chemolithotrophic metabolisms. Second, near-complete prokaryotic 16S rRNA gene clone analysis was conducted for representative microbial mat communities at the upper, middle and downstream sites. The results indicated a dynamic shift in the 16S rRNA gene phylotype composition through physical and chemical variations of the stream water. The predominant prokaryotic components varied from phylotypes related to hydrogeno (H2)- and thio (S)-trophic Aquificales, thermophilic methanotrophs and putative ammonia-oxidizing Archaea (AOA) located upstream (72 °C) to the phylotypes affiliated with putative AOA and nitrite-oxidizing bacteria (NOB) located at the middle and downstream sites (65 and 57 °C, respectively). In addition, the potential in situ metabolic activities of different forms of nitrogen metabolism were estimated through laboratory experiments using bulk microbial mat communities. Finally, the compositional and isotopic variation in nitrogen compounds was investigated in the stream water flowing over the microbial mats and in the interstitial water inside the mats. Although the stream water was characterized by a gradual decrease in the total ammonia concentration (ΣNH3: the sum of ammonia and ammonium concentrations) and a gradual increase in the total concentration of nitrite and nitrate (NO2- + NO3-), the total inorganic nitrogen concentration (TIN: the sum of ΣNH3, NO2- and NO3- concentrations
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Contributions of ectomycorrhizal fungal mats to forest soil respiration
C. Phillips; L.A. Kluber; J.P. Martin; B.A. Caldwell; B.J. Bond
2012-01-01
Distinct aggregations of fungal hyphae and rhizomorphs, or âmatsâ, formed by some genera of ectomycorrhizal (EcM) fungi are common features of soils in coniferous forests of the Pacific Northwest. We measured in situ respiration rates of Piloderma mats and neighboring non-mat soils in an old-growth Douglas-fir forest in western Oregon to investigate whether there was...
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Update on entecavir in the management of severe forms of Hepatitis B
Directory of Open Access Journals (Sweden)
Sacco R
2012-05-01
Full Text Available Rodolfo SaccoDepartment of Gastroenterology, Pisa University Hospital, Pisa, ItalyAbstract: Despite the effective management of most cases of hepatitis B virus (HBV infection, there is still much room for improvement in the treatment of more severe cases of hepatitis B, such as those occurring in patients with decompensated cirrhosis, in transplanted subjects, and in patients with exacerbations of HBV infection. Among the treatments currently approved for the therapy of hepatitis B, entecavir determines a rapid suppression of viral load. This drug is also associated with a high genetic barrier and an overall favorable safety profile. This review provides an overview of recent evidence related to the use of entecavir in the management of the most severe forms of hepatitis B. The results obtained for this drug in real-life clinical practice are also reviewed.Keywords: entecavir, HBV, hepatitis B, chronic hepatitis
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Concentration and transport of nitrate by the mat-forming sulphur bacterium Thioploca
Fossing, H.; Gallardo, V. A.; Jørgensen, B. B.; Hüttel, M.; Nielsen, L. P.; Schulz, H.; Canfield, D. E.; Forster, S.; Glud, R. N.; Gundersen, J. K.; Küver, J.; Ramsing, N. B.; Teske, A.; Thamdrup, B.; Ulloa, O.
1995-04-01
MARINE species of Thioploca occur over 3,000 km along the continental shelf off Southern Peru and North and Central Chile1-4. These filamentous bacteria live in bundles surrounded by a common sheath and form thick mats on the sea floor under the oxygen-minimum zone in the upwelling region, at between 40 and 280 m water depth. The metabolism of this marine bacterium5,6 remained a mystery until long after its discovery1,7. We report here that Thioploca cells are able to concentrate nitrate to up to 500 mM in a liquid vacuole that occupies >80% of the cell volume. Gliding filaments transport this nitrate 5-10 cm down into the sediment and reduce it, with concomitant oxidation of hydrogen sulphide, thereby coupling the nitrogen and sulphur cycles in the sediment.
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Microbial mat ecosystems: Structure types, functional diversity, and biotechnological application
Directory of Open Access Journals (Sweden)
Cristina M. Prieto-Barajas
2018-01-01
Full Text Available Microbial mats are horizontally stratified microbial communities, exhibiting a structure defined by physiochemical gradients, which models microbial diversity, physiological activities, and their dynamics as a whole system. These ecosystems are commonly associated with aquatic habitats, including hot springs, hypersaline ponds, and intertidal coastal zones and oligotrophic environments, all of them harbour phototrophic mats and other environments such as acidic hot springs or acid mine drainage harbour non-photosynthetic mats. This review analyses the complex structure, diversity, and interactions between the microorganisms that form the framework of different types of microbial mats located around the globe. Furthermore, the many tools that allow studying microbial mats in depth and their potential biotechnological applications are discussed.
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Mucoadhesive electrospun chitosan-based nanofibre mats for dental caries prevention.
Samprasit, Wipada; Kaomongkolgit, Ruchadaporn; Sukma, Monrudee; Rojanarata, Theerasak; Ngawhirunpat, Tanasait; Opanasopit, Praneet
2015-03-06
The mucoadhesive electrospun nanofibre mats were developed using chitosan (CS) and thiolated chitosan (CS-SH) as mucoadhesive polymers. Garcinia mangostana (GM) extract was incorporated into nanofibre mats. The antibacterial activity in the single and combined agents was evaluated against dental caries pathogens. The morphology of mats was observed using SEM. The mats were evaluated for GM extract amount, mucoadhesion, in vitro release, antibacterial activity and cytotoxicity. The mucoadhesion and antibacterial activity were determined in healthy human volunteers. The prepared mats were in nanoscale with good physical and mucoadhesive properties. The CS-SH caused the higher mucoadhesion. All mats rapidly released active substances, which had the synergistic antibacterial activity. In addition, the reduction of bacteria and good mucoadhesion in the oral cavity occurred without cytotoxicity. The results suggest that mats have the potential to be mucoadhesive dosage forms to maintain oral hygiene by reducing the bacterial growth that causes the dental caries. Copyright © 2014 Elsevier Ltd. All rights reserved.
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DEFF Research Database (Denmark)
2012-01-01
Talking Mats are visualizations in the handy size of a set of cards used to support interviews with people with mental disabilities.......Talking Mats are visualizations in the handy size of a set of cards used to support interviews with people with mental disabilities....
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Spatial patterns of cyanobacterial mat growth on sand ripples
Mariotti, G.; Klepac-Ceraj, V.; Perron, J. T.; Bosak, T.
2016-02-01
Photosynthetic microbial mats produce organic matter, cycle nutrients, bind pollutants and stabilize sediment in sandy marine environments. Here, we investigate the influence of bedforms and wave motion on the growth rate, composition and spatial variability of microbial mats by growing cyanobacterial mats on a rippled bed of carbonate sand in a wave tank. The tank was forced with an oscillatory flow with velocities below the threshold for sediment motion yet able to induce a porewater flow within the sediment. Different spatial patterns developed in mats depending on the initial biochemistry of the water medium. When growing in a medium rich in nitrogen, phosphorous and micronutrients, mats grew faster on ripple troughs than on ripple crests. After two months, mats covered the bed surface uniformly, and the microbial communities on the crests and in the troughs had similar compositions. Differences in bed shear stress and nutrient availability between crests and troughs were not able to explain the faster growth in the troughs. We hypothesize that this growth pattern is due to a "strainer" effect, i.e. the suspended bacteria from the inoculum were preferentially delivered to troughs by the wave-induced porewater flow. In the experiments initiated in a medium previously used up by a microbial mat and thus depleted in nutrients, mats grew preferentially on the ripple crests. This spatial pattern persisted for nearly two years, and the microbial composition on troughs and crests was different. We attribute this pattern to the upwelling of porewater in the crests, which increased the delivery of nutrients from sediment to the cyanobacteria on the bed surface. Thus, the macroscopic patterns formed by photosynthetic microbial mats on sand ripples may be used to infer whether mats are nutrient-limited and whether they are recently colonized or older than a month.
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Feature Hepatitis: Hepatitis Can Strike Anyone
... Navigation Bar Home Current Issue Past Issues Feature Hepatitis Hepatitis Can Strike Anyone Past Issues / Spring 2009 Table ... from all walks of life are affected by hepatitis, especially hepatitis C, the most common form of ...
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Brandes, Josephin; Kuhajek, Jeanne M; Goodwin, Eric; Wood, Susanna A
2016-10-01
Didymosphenia geminata (Lyngbye) M. Schmidt is a stalked freshwater diatom that is expanding its range globally. In some rivers, D. geminata forms thick and expansive polysaccharide-dominated mats. Like other stalked diatoms, D. geminata cells attach to the substratum with a pad of adhesive extracellular polymeric substance. Research on D. geminata and other diatoms suggests that bacterial biofilm composition may contribute to successful attachment. The aim of this study was to investigate the composition and role of bacterial biofilm communities in D. geminata attachment and survival. Bacterial biofilms were collected at four sites in the main stem of a river (containing D. geminata) and in four tributaries (free of D. geminata). Samples were characterised using automated rRNA intergenic spacer analysis and high-throughput sequencing (HTS). Mat-associated bacteria were isolated and their effect on the early establishment of D. geminata cells assessed using co-culturing experiments. ARISA and HTS data showed differences in bacterial communities between samples with and without D. geminata at two of the four sites. Samples with D. geminata had a higher relative abundance of Sphingobacteria (p geminata reduced survival (p geminata. Attachment was enhanced by Micrococcus sp. and Pseudomonas sp. (p geminata, and may partly explain observed distribution patterns.
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Biodiversity of the microbial mat of the Garga hot spring.
Rozanov, Alexey Sergeevich; Bryanskaya, Alla Victorovna; Ivanisenko, Timofey Vladimirovich; Malup, Tatyana Konstantinovna; Peltek, Sergey Evgenievich
2017-12-28
Microbial mats are a good model system for ecological and evolutionary analysis of microbial communities. There are more than 20 alkaline hot springs on the banks of the Barguzin river inflows. Water temperature reaches 75 °C and pH is usually 8.0-9.0. The formation of microbial mats is observed in all hot springs. Microbial communities of hot springs of the Baikal rift zone are poorly studied. Garga is the biggest hot spring in this area. In this study, we investigated bacterial and archaeal diversity of the Garga hot spring (Baikal rift zone, Russia) using 16S rRNA metagenomic sequencing. We studied two types of microbial communities: (i) small white biofilms on rocks in the points with the highest temperature (75 °C) and (ii) continuous thick phototrophic microbial mats observed at temperatures below 70 °C. Archaea (mainly Crenarchaeota; 19.8% of the total sequences) were detected only in the small biofilms. The high abundance of Archaea in the sample from hot springs of the Baikal rift zone supplemented our knowledge of the distribution of Archaea. Most archaeal sequences had low similarity to known Archaea. In the microbial mats, primary products were formed by cyanobacteria of the genus Leptolyngbya. Heterotrophic microorganisms were mostly represented by Actinobacteria and Proteobacteria in all studied samples of the microbial mats. Planctomycetes, Chloroflexi, and Chlorobi were abundant in the middle layer of the microbial mats, while heterotrophic microorganisms represented mostly by Firmicutes (Clostridia, strict anaerobes) dominated in the bottom part. Besides prokaryotes, we detect some species of Algae with help of detection their chloroplasts 16 s rRNA. High abundance of Archaea in samples from hot springs of the Baikal rift zone supplemented our knowledge of the distribution of Archaea. Most archaeal sequences had low similarity to known Archaea. Metagenomic analysis of microbial communities of the microbial mat of Garga hot spring showed that
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Mating-Type Genes and MAT Switching in Saccharomyces cerevisiae
Haber, James E.
2012-01-01
Mating type in Saccharomyces cerevisiae is determined by two nonhomologous alleles, MATa and MATα. These sequences encode regulators of the two different haploid mating types and of the diploids formed by their conjugation. Analysis of the MATa1, MATα1, and MATα2 alleles provided one of the earliest models of cell-type specification by transcriptional activators and repressors. Remarkably, homothallic yeast cells can switch their mating type as often as every generation by a highly choreographed, site-specific homologous recombination event that replaces one MAT allele with different DNA sequences encoding the opposite MAT allele. This replacement process involves the participation of two intact but unexpressed copies of mating-type information at the heterochromatic loci, HMLα and HMRa, which are located at opposite ends of the same chromosome-encoding MAT. The study of MAT switching has yielded important insights into the control of cell lineage, the silencing of gene expression, the formation of heterochromatin, and the regulation of accessibility of the donor sequences. Real-time analysis of MAT switching has provided the most detailed description of the molecular events that occur during the homologous recombinational repair of a programmed double-strand chromosome break. PMID:22555442
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Directory of Open Access Journals (Sweden)
Anne D. Jungblut
2013-01-01
Full Text Available Lake Vanda is a perennially ice-covered, closed-basin lake in the McMurdo Dry Valleys, Antarctica. Laminated photosynthetic microbial mats cover the floor of the lake from below the ice cover to >40 m depth. In recent decades, the water level of Lake Vanda has been rising, creating a “natural experiment” on development of mat communities on newly flooded substrates and the response of deeper mats to declining irradiance. Mats in recently flooded depths accumulate one lamina (~0.3 mm per year and accrue ~0.18 µg chlorophyll-a cm−2 y−1. As they increase in thickness, vertical zonation becomes evident, with the upper 2-4 laminae forming an orange-brown zone, rich in myxoxanthophyll and dominated by intertwined Leptolyngbya trichomes. Below this, up to six phycobilin-rich green/pink-pigmented laminae form a subsurface zone, inhabited by Leptolyngbya, Oscillatoria and Phormidium morphotypes. Laminae continued to increase in thickness for several years after burial, and PAM fluorometry indicated photosynthetic potential in all pigmented laminae. At depths that have been submerged for >40 years, mats showed similar internal zonation and formed complex pinnacle structures that were only beginning to appear in shallower mats. Chlorophyll-a did not change over time and these mats appear to represent resource-limited “climax” communities. Acclimation of microbial mats to changing environmental conditions is a slow process, and our data show how legacy effects of past change persist into the modern community structure.
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Tracing biosignatures from the Recent to the Jurassic in sabkha-associated microbial mats
van der Land, Cees; Dutton, Kirsten; Andrade, Luiza; Paul, Andreas; Sherry, Angela; Fender, Tom; Hewett, Guy; Jones, Martin; Lokier, Stephen W.; Head, Ian M.
2017-04-01
Microbial mat ecosystems have been operating at the sediment-fluid interface for over 3400 million years, influencing the flux, transformation and preservation of carbon from the biosphere to the physical environment. These ecosystems are excellent recorders of rapid and profound changes in earth surface environments and biota as they often survive crisis-induced extreme paleoenvironmental conditions. Their biosignatures, captured in the preserved organic matter and the biominerals that form the microbialite rock, constitute a significant tool in understanding geobiological processes and the interactions of the microbial communities with sediments and with the prevailing physical chemical parameters, as well as the environmental conditions at a local and global scale. Nevertheless, the exact pathways of diagenetic organic matter transformation and early-lithification, essential for the accretion and preservation in the geological record as microbialites, are not well understood. The Abu Dhabi coastal sabkha system contains a vast microbial mat belt that is dominated by continuous polygonal and internally-laminated microbial mats across the upper and middle intertidal zones. This modern system is believed to be the best analogue for the Upper Jurassic Arab Formation, which is both a prolific hydrocarbon reservoir and source rock facies in the United Arab Emirates and in neighbouring countries. In order to characterise the processes that lead to the formation of microbialites we investigated the modern and Jurassic system using a multidisciplinary approach, including growth of field-sampled microbial mats under controlled conditions in the laboratory and field-based analysis of microbial communities, mat mineralogy and organic biomarker analysis. In this study, we focus on hydrocarbon biomarker data obtained from the surface of microbial mats actively growing in the intertidal zone of the modern system. By comparing these findings to data obtained from recently
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MatLab Script and Functional Programming
Shaykhian, Gholam Ali
2007-01-01
MatLab Script and Functional Programming: MatLab is one of the most widely used very high level programming languages for scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems. Specifically provided are programs for visualization. The MatLab seminar covers the functional and script programming aspect of MatLab language. Specific expectations are: a) Recognize MatLab commands, script and function. b) Create, and run a MatLab function. c) Read, recognize, and describe MatLab syntax. d) Recognize decisions, loops and matrix operators. e) Evaluate scope among multiple files, and multiple functions within a file. f) Declare, define and use scalar variables, vectors and matrices.
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Water flow and solute transport in floating fen root mats
Stofberg, Sija F.; EATM van der Zee, Sjoerd
2015-04-01
Floating fens are valuable wetlands, found in North-Western Europe, that are formed by floating root mats when old turf ponds are colonized by plants. These terrestrialization ecosystems are known for their biodiversity and the presence of rare plant species, and the root mats reveal different vegetation zones at a small scale. The vegetation zones are a result of strong gradients in abiotic conditions, including groundwater dynamics, nutrients and pH. To prevent irreversible drought effects such as land subsidence and mineralization of peat, water management involves import of water from elsewhere to maintain constant surface water levels. Imported water may have elevated levels of salinity during dry summers, and salt exposure may threaten the vegetation. To assess the risk of exposure of the rare plant species to salinity, the hydrology of such root mats must be understood. Physical properties of root mats have scarcely been investigated. We have measured soil characteristics, hydraulic conductivity, vertical root mat movement and groundwater dynamics in a floating root mat in the nature reserve Nieuwkoopse Plassen, in the Netherlands. The root mat mostly consists of roots and organic material, in which the soil has a high saturated water content, and strongly varies in its stage of decomposition. We have found a distinct negative correlation between degree of decomposition and hydraulic conductivity, similar to observations for bogs in the literature. Our results show that the relatively young, thin edge of the root mat that colonizes the surface water has a high hydraulic conductivity and floats in the surface water, resulting in very small groundwater fluctuations within the root mat. The older part of the root mat, that is connected to the deeper peat layers is hydrologically more isolated and the material has a lower conductivity. Here, the groundwater fluctuates strongly with atmospheric forcing. The zones of hydraulic properties and vegetation, appear to
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Jessen, Gerdhard L; Lichtschlag, Anna; Struck, Ulrich; Boetius, Antje
2016-01-01
At the Black Sea chemocline, oxygen- and sulfide-rich waters meet and form a niche for thiotrophic pelagic bacteria. Here we investigated an area of the Northwestern Black Sea off Crimea close to the shelf break, where the chemocline reaches the seafloor at around 150-170 m water depth, to assess whether thiotrophic bacteria are favored in this zone. Seafloor video transects were carried out with the submersible JAGO covering 20 km(2) on the region between 110 and 200 m depth. Around the chemocline we observed irregular seafloor depressions, covered with whitish mats of large filamentous bacteria. These comprised 25-55% of the seafloor, forming a belt of 3 km width around the chemocline. Cores from the mats obtained with JAGO showed higher accumulations of organic matter under the mats compared to mat-free sediments. The mat-forming bacteria were related to Beggiatoa-like large filamentous sulfur bacteria based on 16S rRNA sequences from the mat, and visual characteristics. The microbial community under the mats was significantly different from the surrounding sediments and enriched with taxa affiliated with polymer degrading, fermenting and sulfate reducing microorganisms. Under the mats, higher organic matter accumulation, as well as higher remineralization and radiotracer-based sulfate reduction rates were measured compared to outside the mat. Mat-covered and mat-free sediments showed similar degradability of the bulk organic matter pool, suggesting that the higher sulfide fluxes and subsequent development of the thiotrophic mats in the patches are consequences of the accumulation of organic matter rather than its qualitative composition. Our observations suggest that the key factors for the distribution of thiotrophic mat-forming communities near to the Crimean shelf break are hypoxic conditions that (i) repress grazers, (ii) enhance the accumulation and degradation of labile organic matter by sulfate-reducers, and (iii) favor thiotrophic filamentous bacteria
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DEFF Research Database (Denmark)
2016-01-01
of fibers. The fibers may further include particles of a catalyst. The fiber mat may be used to form an electrode or a membrane. In a further aspect, a fuel cell membrane-electrode-assembly has an anode electrode, a cathode electrode, and a membrane disposed between the anode electrode and the cathode...... electrode. Each of the anode electrode, the cathode electrode and the membrane may be formed with a fiber mat....
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Concentration and Transport of Nitrate by the Mat-Forming Sulfur Bacterium Thioploca Rid E-1821-2011
DEFF Research Database (Denmark)
FOSSING, H.; GALLARDO, VA; JØRGENSEN, BB
1995-01-01
MARINE species of Thioploca occur over 3,000 km along the continental shelf off Southern Peru and North and Central Chile(1-4). These filamentous bacteria live in bundles surrounded by a common sheath and form thick mats on the sea floor under the oxygen-minimum zone in the upwelling region......, at between 40 and 280 m water depth. The metabolism of this marine bacterium(5,6) remained a mystery until long after its discovery(1,7). We report here that Thioploca cells are able to concentrate nitrate to up to 500 mM in a liquid vacuole that occupies >80% of the cell volume. Gliding filaments transport...... this nitrate 5-10 cm down into the sediment and reduce it, with concomitant oxidation of hydrogen sulphide, thereby coupling the nitrogen and sulphur cycles in the sediment....
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Samprasit, Wipada; Rojanarata, Theerasak; Akkaramongkolporn, Prasert; Ngawhirunpat, Tanasait; Kaomongkolgit, Ruchadaporn; Opanasopit, Praneet
2015-10-01
This study aimed to fabricate mucoadhesive electrospun nanofiber mats containing α-mangostin for the maintenance of oral hygiene and reduction of the bacterial growth that causes dental caries. Synthesized thiolated chitosan (CS-SH) blended with polyvinyl alcohol (PVA) was selected as the mucoadhesive polymer. α-Mangostin was incorporated into the CS-SH/PVA solution and electrospun to obtain nanofiber mats. Scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, and tensile strength testing were used to characterize the mats. The swelling degree and mucoadhesion were also determined. The nanofiber mats were further evaluated regarding their α-mangostin content, in vitro α-mangostin release, antibacterial activity, cytotoxicity, in vivo performance, and stability. The results indicated that the mats were in the nanometer range. The α-mangostin was well incorporated into the mats, with an amorphous form. The mats showed suitable tensile strength, swelling, and mucoadhesive properties. The loading capacity increased when the initial amount of α-mangostin was increased. Rapid release of α-mangostin from the mats was achieved. Additionally, a fast bacterial killing rate occurred at the lowest concentration of nanofiber mats when α-mangostin was added to the mats. The mats were less cytotoxic after use for 72 h. Moreover, in vivo testing indicated that the mats could reduce the number of oral bacteria, with a good mouth feel. The mats maintained the amount of α-mangostin for 6 months. The results suggest that α-mangostin-loaded mucoadhesive electrospun nanofiber mats may be a promising material for oral care and the prevention of dental caries.
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Schneider, Dominik; Arp, Gernot; Reimer, Andreas; Reitner, Joachim; Daniel, Rolf
2013-01-01
On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰). Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster), which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria), Chloroflexi (Anaerolineae and Caldilineae), purple non-sulfur bacteria (Alphaproteobacteria), purple sulfur bacteria (Chromatiales), anaerobic Bacteroidetes (Marinilabiacae), Nitrospirae (OPB95), Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata) to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B) with increasing depth.
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Directory of Open Access Journals (Sweden)
Dominik Schneider
Full Text Available On the Kiritimati atoll, several lakes exhibit microbial mat-formation under different hydrochemical conditions. Some of these lakes trigger microbialite formation such as Lake 21, which is an evaporitic, hypersaline lake (salinity of approximately 170‰. Lake 21 is completely covered with a thick multilayered microbial mat. This mat is associated with the formation of decimeter-thick highly porous microbialites, which are composed of aragonite and gypsum crystals. We assessed the bacterial and archaeal community composition and its alteration along the vertical stratification by large-scale analysis of 16S rRNA gene sequences of the nine different mat layers. The surface layers are dominated by aerobic, phototrophic, and halotolerant microbes. The bacterial community of these layers harbored Cyanobacteria (Halothece cluster, which were accompanied with known phototrophic members of the Bacteroidetes and Alphaproteobacteria. In deeper anaerobic layers more diverse communities than in the upper layers were present. The deeper layers were dominated by Spirochaetes, sulfate-reducing bacteria (Deltaproteobacteria, Chloroflexi (Anaerolineae and Caldilineae, purple non-sulfur bacteria (Alphaproteobacteria, purple sulfur bacteria (Chromatiales, anaerobic Bacteroidetes (Marinilabiacae, Nitrospirae (OPB95, Planctomycetes and several candidate divisions. The archaeal community, including numerous uncultured taxonomic lineages, generally changed from Euryarchaeota (mainly Halobacteria and Thermoplasmata to uncultured members of the Thaumarchaeota (mainly Marine Benthic Group B with increasing depth.
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Photosynthetic Microbial Mats are Exemplary Sources of Diverse Biosignatures (Invited)
Des Marais, D. J.; Jahnke, L. L.
2013-12-01
microorganisms as well as networks of C flow within mats; thus they offer insights about community structure. For example, relative 13C/12C values of individual lipid biosignatures can indicate trophic relationships between key groups of microorganisms. Mat microenvironments can affect the stability of authigenic minerals and alter the chemical compositions and crystal forms of carbonate, sulfate and metal oxide minerals. Interactions between low molecular weight organic compounds and sulfides in mat pore waters can produce alkyl sulfide gases. Processes associated with these physically coherent biofilms can trap and bind detrital grains, enhance mineral precipitation or dissolution, and stabilize sediment surfaces. Accordingly mats can create distinctive sedimentary fabrics and structures. Stromatolites are the most ancient, widespread examples of such fabrics and structures. Thus photosynthetic microbial mats create diverse biosignatures that, when preserved in the geologic record, can help to identify the former presence of key populations of microorganisms and reveal key processes that occurred within ancient mats as well as the interactions between those ecosystems and their environment.
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Jessen, Gerdhard L.; Lichtschlag, Anna; Struck, Ulrich; Boetius, Antje
2016-01-01
At the Black Sea chemocline, oxygen- and sulfide-rich waters meet and form a niche for thiotrophic pelagic bacteria. Here we investigated an area of the Northwestern Black Sea off Crimea close to the shelf break, where the chemocline reaches the seafloor at around 150–170 m water depth, to assess whether thiotrophic bacteria are favored in this zone. Seafloor video transects were carried out with the submersible JAGO covering 20 km2 on the region between 110 and 200 m depth. Around the chemocline we observed irregular seafloor depressions, covered with whitish mats of large filamentous bacteria. These comprised 25–55% of the seafloor, forming a belt of 3 km width around the chemocline. Cores from the mats obtained with JAGO showed higher accumulations of organic matter under the mats compared to mat-free sediments. The mat-forming bacteria were related to Beggiatoa-like large filamentous sulfur bacteria based on 16S rRNA sequences from the mat, and visual characteristics. The microbial community under the mats was significantly different from the surrounding sediments and enriched with taxa affiliated with polymer degrading, fermenting and sulfate reducing microorganisms. Under the mats, higher organic matter accumulation, as well as higher remineralization and radiotracer-based sulfate reduction rates were measured compared to outside the mat. Mat-covered and mat-free sediments showed similar degradability of the bulk organic matter pool, suggesting that the higher sulfide fluxes and subsequent development of the thiotrophic mats in the patches are consequences of the accumulation of organic matter rather than its qualitative composition. Our observations suggest that the key factors for the distribution of thiotrophic mat-forming communities near to the Crimean shelf break are hypoxic conditions that (i) repress grazers, (ii) enhance the accumulation and degradation of labile organic matter by sulfate-reducers, and (iii) favor thiotrophic filamentous bacteria
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Hydroponic root mats for wastewater treatment-a review.
Chen, Zhongbing; Cuervo, Diego Paredes; Müller, Jochen A; Wiessner, Arndt; Köser, Heinz; Vymazal, Jan; Kästner, Matthias; Kuschk, Peter
2016-08-01
Hydroponic root mats (HRMs) are ecotechnological wastewater treatment systems where aquatic vegetation forms buoyant filters by their dense interwoven roots and rhizomes, sometimes supported by rafts or other floating materials. A preferential hydraulic flow is created in the water zone between the plant root mat and the bottom of the treatment system. When the mat touches the bottom of the water body, such systems can also function as HRM filter; i.e. the hydraulic flow passes directly through the root zone. HRMs have been used for the treatment of various types of polluted water, including domestic wastewater; agricultural effluents; and polluted river, lake, stormwater and groundwater and even acid mine drainage. This article provides an overview on the concept of applying floating HRM and non-floating HRM filters for wastewater treatment. Exemplary performance data are presented, and the advantages and disadvantages of this technology are discussed in comparison to those of ponds, free-floating plant and soil-based constructed wetlands. Finally, suggestions are provided on the preferred scope of application of HRMs.
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Energy Technology Data Exchange (ETDEWEB)
Ma, Hui [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Huang, Yunpeng; Shen, Mingwu; Guo, Rui; Cao, Xueyan [College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); Shi, Xiangyang, E-mail: xshi@dhu.edu.cn [State Key Laboratory for Modification of Chemical Fibers and Polymer Materials, Donghua University, Shanghai 201620 (China); College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620 (China); CQM - Centro de Quimica da Madeira, Universidade da Madeira, Campus da Penteada, 9000-390 Funchal (Portugal)
2012-04-15
Fe/Pd bimetallic nanoparticles (NPs) have held great promise for treating trichloroethylene (TCE)-contaminated groundwater, without the accumulation of chlorinated intermediates. However, the conventionally used colloidal Fe/Pd NPs usually aggregate rapidly, resulting in a reduced reactivity. To reduce the particle aggregation, we employed electrospun polyacrylic acid (PAA)/polyvinyl alcohol (PVA) polymer nanofibers as a nanoreactor to immobilize Fe/Pd bimetallic NPs. In the study, the water-stable PAA/PVA nanofibrous mats were complexed with Fe (III) ions via the binding with the free carboxyl groups of PAA for subsequent formation and immobilization of zero-valent iron (ZVI) NPs. Fe/Pd bimetallic NPs were then formed by the partial reduction of Pd(II) ions with ZVI NPs. The formed electrospun nanofibrous mats containing Fe/Pd bimetallic NPs with a diameter of 2.8 nm were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, thermogravimetric analysis, and inductively coupled plasma-atomic emission spectroscopy. The Fe/Pd NP-containing electrospun PAA/PVA nanofibrous mats exhibited higher reactivity than that of the ZVI NP-containing mats or colloidal Fe/Pd NPs in the dechlorination of trichloroethylene (TCE), which was used as a model contaminant. With the high surface area to volume ratio, high porosity, and great reusability of the fibrous mats immobilized with the bimetallic NPs, the composite nanofibrous mats should be amenable for applications in remediation of various environmental contaminants.
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International Nuclear Information System (INIS)
Ma, Hui; Huang, Yunpeng; Shen, Mingwu; Guo, Rui; Cao, Xueyan; Shi, Xiangyang
2012-01-01
Fe/Pd bimetallic nanoparticles (NPs) have held great promise for treating trichloroethylene (TCE)-contaminated groundwater, without the accumulation of chlorinated intermediates. However, the conventionally used colloidal Fe/Pd NPs usually aggregate rapidly, resulting in a reduced reactivity. To reduce the particle aggregation, we employed electrospun polyacrylic acid (PAA)/polyvinyl alcohol (PVA) polymer nanofibers as a nanoreactor to immobilize Fe/Pd bimetallic NPs. In the study, the water-stable PAA/PVA nanofibrous mats were complexed with Fe (III) ions via the binding with the free carboxyl groups of PAA for subsequent formation and immobilization of zero-valent iron (ZVI) NPs. Fe/Pd bimetallic NPs were then formed by the partial reduction of Pd(II) ions with ZVI NPs. The formed electrospun nanofibrous mats containing Fe/Pd bimetallic NPs with a diameter of 2.8 nm were characterized by scanning electron microscopy, energy-dispersive spectroscopy, transmission electron microscopy, thermogravimetric analysis, and inductively coupled plasma-atomic emission spectroscopy. The Fe/Pd NP-containing electrospun PAA/PVA nanofibrous mats exhibited higher reactivity than that of the ZVI NP-containing mats or colloidal Fe/Pd NPs in the dechlorination of trichloroethylene (TCE), which was used as a model contaminant. With the high surface area to volume ratio, high porosity, and great reusability of the fibrous mats immobilized with the bimetallic NPs, the composite nanofibrous mats should be amenable for applications in remediation of various environmental contaminants.
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Black Mats, Spring-Fed Streams, and Late-Glacial-Age Recharge in the Southern Great Basin
Quade, Jay; Forester, R.M.; Pratt, W.L.; Carter, C.
1998-01-01
Black mats are prominent features of the late Pleistocene and Holocene stratigraphic record in the southern Great Basin. Faunal, geochemical, and sedimentological evidence shows that the black mats formed in several microenvironments related to spring discharge, ranging from wet meadows to shallow ponds. Small land snails such as Gastrocopta tappaniana and Vertigo berryi are the most common mollusk taxa present. Semiaquatic and aquatic taxa are less abundant and include Catinellids, Fossaria parva, Gyraulus parvus, and others living today in and around perennial seeps and ponds. The ostracodes Cypridopsis okeechobi and Scottia tumida, typical of seeps and low-discharge springs today, as well as other taxa typical of springs and wetlands, are common in the black mats. Several new species that lived in the saturated subsurface also are present, but lacustrine ostracodes are absent. The ??13C values of organic matter in the black mats range from -12 to -26???, reflecting contributions of tissue from both C3 (sedges, most shrubs and trees) and C4 (saltbush, saltgrass) plants. Carbon-14 dates on the humate fraction of 55 black mats fall between 11,800 to 6300 and 2300 14C yr B.P. to modern. The total absence of mats in our sample between 6300 and 2300 14C yr B.P. likely reflects increased aridity associated with the mid-Holocene Altithermal. The oldest black mats date to 11,800-11,600 14C yr B.P., and the peak in the 14C black mat distribution falls at ???10,000 14C yr B.P. As the formation of black mats is spring related, their abundance reflects refilling of valley aquifers starting no later than 11,800 and peaking after 11,000 14C yrB.P. Reactivation of spring-fed channels shortly before 11,200 14C yr B.P. is also apparent in the stratigraphic records from the Las Vegas and Pahrump Valleys. This age distribution suggests that black mats and related spring-fed channels in part may have formed in response to Younger Dryas (YD)-age recharge in the region. However, the
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Living Dendrolitic Microbial Mats in Hamelin Pool, Shark Bay, Western Australia
Directory of Open Access Journals (Sweden)
Erica P. Suosaari
2018-06-01
Full Text Available Hamelin Pool, Shark Bay, Western Australia, is home to the largest and most diverse assemblage of living marine stromatolites, with shapes and sizes comparable to ancient structures. A recent field-intensive program revealed seasonally ephemeral occurrences of modern dendrolitic microbial mats forming in intertidal, low energy settings. Dominated by filamentous cyanobacteria, dendrolitic microbial mats are formed when filaments provide a supporting framework as a result of gliding mobility, to build a shrubby morphology. Dendrolites, known throughout the rock record, refer to macroscopic microbialites with mesostuctures composed of unlaminated arborescent structures called shrubs. In these modern examples, thick filaments of Lyngbya aestuarii form the “trunk” of the bush, with finer filaments of Lyngbya fragilis, Phormidium sp. and Schizothrix sp. forming the “branches” These biologically-influenced dendrolitic structures provide insight into the complex interplay of microbial communities and the environment, broadening our understanding of shrub and dendrolite formation throughout the rock record.
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Yamamoto, Hiroyuki; Hiraishi, Akira; Kato, Kenji; Chiura, Hiroshi X.; Maki, Yonosuke; Shimizu, Akira
1998-01-01
So-called sulfur-turf microbial mats, which are macroscopic white filaments or bundles consisting of large sausage-shaped bacteria and elemental sulfur particles, occur in sulfide-containing hot springs in Japan. However, no thermophiles from sulfur-turf mats have yet been isolated as cultivable strains. This study was undertaken to determine the phylogenetic positions of the sausage-shaped bacteria in sulfur-turf mats by direct cloning and sequencing of 16S rRNA genes amplified from the bulk DNAs of the mats. Common clones with 16S rDNA sequences with similarity levels of 94.8 to 99% were isolated from sulfur-turf mat samples from two geographically remote hot springs. Phylogenetic analysis showed that the phylotypes of the common clones formed a major cluster with members of the Aquifex-Hydrogenobacter complex, which represents the most deeply branching lineage of the domain bacteria. Furthermore, the bacteria of the sulfur-turf mat phylotypes formed a clade distinguishable from that of other members of the Aquifex-Hydrogenobacter complex at the order or subclass level. In situ hybridization with clone-specific probes for 16S rRNA revealed that the common phylotype of sulfur-turf mat bacteria is that of the predominant sausage-shaped bacteria. PMID:9572936
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Cullis, James D. S.; Gillis, Carole-Anne; Bothwell, Max L.; Kilroy, Cathy; Packman, Aaron; Hassan, Marwan
2012-06-01
The benthic, mat-forming diatomDidymosphenia geminata has the unique ability to produce large amounts of algal biomass under oligotrophic conditions in cold, fast flowing streams and rivers. This presents an ecological paradox that challenges our current understanding of stream ecosystem dynamics. Our understanding of the drivers of D. geminata ecology is still limited. Here we present a conceptual model for the blooming behavior and persistence of this species to advance scientific understanding of strategies for life in fast flowing oligotrophic waters and support the design of future research and mitigation measures for nuisance algal blooms. The conceptual model is based on a synthesis of data and ideas from a range of disciplines including hydrology, geomorphology, biogeochemistry, and ecology. The conceptual model highlights the role of water chemistry, river morphology, and flow thresholds in defining the habitat window for D. geminata. We propose that bed disturbance is a primary control on accumulation and persistence of D. geminataand that the removal threshold can be determined by synthesizing site-specific information on hydrology and geomorphology. Further, we propose that a key to understanding the didymo paradox is the separation of cellular reproduction and mat morphology with specific controls acting in respect of the different processes.
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Regulation of mat responses by a differentiation MAPK pathway in Saccharomyces cerevisiae.
Directory of Open Access Journals (Sweden)
Sheelarani Karunanithi
Full Text Available Fungal species exhibit diverse behaviors when presented with extracellular challenges. Pathogenic fungi can undergo cell differentiation and biofilm formation in response to fluctuating nutrient levels, and these responses are required for virulence. In the model fungal eukaryote Saccharomyces cerevisiae, nutrient limitation induces filamentous growth and biofilm/mat formation. Both responses require the same signal transduction (MAPK pathway and the same cell adhesion molecule (Flo11 but have been studied under different conditions. We found that filamentous growth and mat formation are aspects of a related response that is regulated by the MAPK pathway. Cells in yeast-form mats differentiated into pseudohyphae in response to nutrient limitation. The MAPK pathway regulated mat expansion (in the plane of the XY-axis and substrate invasion (downward in the plane of the Z-axis, which optimized the mat's response to extracellular nutrient levels. The MAPK pathway also regulated an upward growth pattern (in the plane of the Z-axis in response to nutrient limitation and changes in surface rigidity. Upward growth allowed for another level of mat responsiveness and resembled a type of colonial chemorepulsion. Together our results show that signaling pathways play critical roles in regulating social behaviors in which fungal cells participate. Signaling pathways may regulate similar processes in pathogens, whose highly nuanced responses are required for virulence.
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DEFF Research Database (Denmark)
Andersen, Ina Trolle; Hahn, Ute
2016-01-01
and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae for the intensity...
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DEFF Research Database (Denmark)
Andersen, Ina Trolle; Hahn, Ute
of clustering and hard core behaviour can be achieved by applying a dependent Matérn thinning to a Cox process. An exact formula for the intensity of a Matérn thinned shot noise Cox process is derived from the Palm distribution. For the more general class of Matérn thinned Cox processes, formulae...
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Biddanda, Bopaiah A; McMillan, Adam C; Long, Stephen A; Snider, Michael J; Weinke, Anthony D
2015-01-01
We studied the motility of filamentous mat-forming cyanobacteria consisting primarily of Oscillatoria-like cells growing under low-light, low-oxygen, and high-sulfur conditions in Lake Huron's submerged sinkholes using in situ observations, in vitro measurements and time-lapse microscopy. Gliding movement of the cyanobacterial trichomes (100-10,000 μm long filaments, composed of cells ∼10 μm wide and ∼3 μm tall) revealed individual as well as group-coordinated motility. When placed in a petri dish and dispersed in ground water from the sinkhole, filaments re-aggregated into defined colonies within minutes, then dispersed again. Speed of individual filaments increased with temperature from ∼50 μm min(-1) or ∼15 body lengths min(-1) at 10°C to ∼215 μm min(-1) or ∼70 body lengths min(-1) at 35°C - rates that are rapid relative to non-flagellated/ciliated microbes. Filaments exhibited precise and coordinated positive phototaxis toward pinpoints of light and congregated under the light of foil cutouts. Such light-responsive clusters showed an increase in photosynthetic yield - suggesting phototactic motility aids in light acquisition as well as photosynthesis. Once light source was removed, filaments slowly spread out evenly and re-aggregated, demonstrating coordinated movement through inter-filament communication regardless of light. Pebbles and pieces of broken shells placed upon intact mat were quickly covered by vertically motile filaments within hours and became fully buried in the anoxic sediments over 3-4 diurnal cycles - likely facilitating the preservation of falling debris. Coordinated horizontal and vertical filament motility optimize mat cohesion and dynamics, photosynthetic efficiency and sedimentary carbon burial in modern-day sinkhole habitats that resemble the shallow seas in Earth's early history. Analogous cyanobacterial motility may have played a key role in the oxygenation of the planet by optimizing photosynthesis while favoring
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Molecular ecology of microbial mats
Bolhuis, H.; Cretoiu, M.S.; Stal, L.J.
2014-01-01
Phototrophic microbial mats are ideal model systems for ecological and evolutionary analysis of highly diverse microbial communities. Microbial mats are small-scale, nearly closed, and self-sustaining benthic ecosystems that comprise the major element cycles, trophic levels, and food webs. The steep
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Tice, Michael M
2009-12-01
Three morphotypes of microbial mats are preserved in rocks deposited in shallow-water facies of the 3.42 Ga Buck Reef chert (BRC). Morphotype alpha consists of fine anastomosing and bifurcating carbonaceous laminations, which loosely drape underlying detrital grains or form silica-filled lenses. Morphotype beta consists of meshes of fine carbonaceous strands intergrown with detrital grains and dark laminations, which loosely drape coarse detrital grains. Morphotype gamma consists of fine, even carbonaceous laminations that tightly drape underlying detrital grains. Preservation of nearly uncompacted mat morphologies and detrital grains deposited during mat growth within a well-characterized sedimentary unit makes quantitative correlation between morphology and paleoenvironment possible. All mats are preserved in the shallowest-water interval of those rocks deposited below normal wave base and above storm wave base. This interval is bounded below by a transgressive lag formed during regional flooding and above by a small condensed section that marks a local relative sea-level maximum. Restriction of all mat morphotypes to the shallowest interval of the storm-active layer in the BRC ocean reinforces previous interpretations that these mats were constructed primarily by photosynthetic organisms. Morphotypes alpha and beta dominate the lower half of this interval and grew during deposition of relatively coarse detrital carbonaceous grains, while morphotype gamma dominates the upper half and grew during deposition of fine detrital carbonaceous grains. The observed mat distribution suggests that either light intensity or, more likely, small variations in ambient current energy acted as a first-order control on mat morphotype distribution. These results demonstrate significant environmental control on biological morphogenetic processes independent of influences from siliciclastic sedimentation.
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Boyd, Eric S; King, Susan; Tomberlin, Jeffery K; Nordstrom, D Kirk; Krabbenhoft, David P; Barkay, Tamar; Geesey, Gill G
2009-04-01
Microbial mats are a visible and abundant life form inhabiting the extreme environments in Yellowstone National Park (YNP), WY, USA. Little is known of their role in food webs that exist in the Park's geothermal habitats. Eukaryotic green algae associated with a phototrophic green/purple Zygogonium microbial mat community that inhabits low-temperature regions of acidic (pH approximately 3.0) thermal springs were found to serve as a food source for stratiomyid (Diptera: Stratiomyidae) larvae. Mercury in spring source water was taken up and concentrated by the mat biomass. Monomethylmercury compounds (MeHg(+)), while undetectable or near the detection limit (0.025 ng l(-1)) in the source water of the springs, was present at concentrations of 4-7 ng g(-1) dry weight of mat biomass. Detection of MeHg(+) in tracheal tissue of larvae grazing the mat suggests that MeHg(+) enters this geothermal food web through the phototrophic microbial mat community. The concentration of MeHg(+) was two to five times higher in larval tissue than mat biomass indicating MeHg(+) biomagnification occurred between primary producer and primary consumer trophic levels. The Zygogonium mat community and stratiomyid larvae may also play a role in the transfer of MeHg(+) to species in the food web whose range extends beyond a particular geothermal feature of YNP.
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Solution-blown nanofiber mats from fish sarcoplasmic protein
DEFF Research Database (Denmark)
Sett, S.; Boutrup Stephansen, Karen; Yarin, A.L.
2016-01-01
In the present work, solution-blowing was adopted to form nanofibers from fish sarcoplasmic proteins (FSPs). Nanofiber mats containing different weight ratios (up to 90/10) of FSP in the FSP/nylon 6 blended nanofibers were formed from formic acid solutions, and compared to electrospun fibers made...... that the production rate of solution-blowing was increased 30-fold in relation to electrospinning. Overall, this study reveals FSP as an interesting biopolymeric alternative to synthetic polymers, and the introduction of FSP to nylon 6 provides a composite with controlled properties....
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Directory of Open Access Journals (Sweden)
Bopaiah A Biddanda
2015-09-01
Full Text Available We studied the motility of filamentous mat-forming cyanobacteria consisting primarily of Oscillatoria-like cells growing under low-light, low-oxygen and high-sulfur conditions in Lake Huron’s submerged sinkholes using in situ observations, in vitro measurements and time-lapse microscopy. Gliding movement of the cyanobacterial trichomes (100-10,000 µm long filaments, composed of cells ~10 µm wide and ~3 µm tall revealed individual as well as group-coordinated motility. When placed in a petri dish and dispersed in ground water from the sinkhole, filaments re-aggregated into defined colonies within minutes, then dispersed again. Speed of individual filaments increased with temperature from ~50 µm minute-1 or ~15 body lengths minute-1 at 10°C to ~215 µm minute-1 or ~70 body lengths minute-1 at 35°C – rates that are rapid relative to non-flagellated/ciliated microbes. Filaments exhibited precise and coordinated positive phototaxis towards pinpoints of light and congregated under the light of foil cutouts. Such light-responsive clusters showed an increase in photosynthetic yield – suggesting phototactic motility aids in light acquisition as well as photosynthesis. Once light source was removed, filaments slowly spread out evenly and re-aggregated, demonstrating coordinated movement through inter-filament communication regardless of light. Pebbles and pieces of broken shells placed upon intact mat were quickly covered by vertically motile filaments within hours and became fully buried in the anoxic sediments over 3-4 diurnal cycles – likely facilitating the preservation of falling debris. Coordinated horizontal and vertical filament motility optimize mat cohesion and dynamics, photosynthetic efficiency and sedimentary carbon burial in modern-day sinkhole habitats that resemble the shallow seas in Earth’s early history. Analogous cyanobacterial motility may have played a key role in the oxygenation of the planet by optimizing
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CLINICAL FEATURES OF REFRACTORY FORMS OF ANEMIA IN CHILDREN WITH CHRONIC HEPATITIS В
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F. I. Inoyаtova
2013-01-01
Full Text Available Examination of 125 children with chronic hepatitis В and concomitant anemia has determined the frequency of refractory forms of anemia (52,5%. The disease progressed more severely on the background of anemia, which was indicated by the prevalence of CHВ forms with severe activity (71,4%. The pathognomonic symptoms of anemic processes were revealed. Two pathogenetic variants of the anemia genesis in children with CHВ are being considered: the first is defined by veritable iron deficiency with ferrokinetic markers of iron-deficiency anemia; the second — by relocationable iron deficit that is typical for hemosiderosis and refractoriness development.
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Siwonhan-mat: The third taste of Korean foods
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Soon Ah Kang
2016-03-01
Conclusion: Siwonhan-mat is a unique sensation found in Korean food. Understanding siwonhan-mat is a key to learning about Korean food and its food culture. Therefore, this paper serves an important role in understanding Korean food. Siwonhan-mat is often mistranslated using words to describe temperature, such as cool. This misinterpretation has resulted in confusion over the original meaning of siwonhan-mat and contributed to the incorrect usage of the word.
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Does siwonhan-mat represent delicious in Korean foods?
Directory of Open Access Journals (Sweden)
Dai Ja Jang
2016-06-01
Conclusion: Balancing kan is a determining factor of siwonhan-mat in Korean cuisine. Particularly, a strong association between siwonhan-mat and deliciousness was found in kuk and tang, suggesting the importance of siwonhan-mat in experiencing the best flavor in Korean food.
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Preparation of Non-Woven Fiber Mats by Mixture of PVC and Epoxidized Natural Rubber
International Nuclear Information System (INIS)
Muhammad Hariz Othman; Mahathir Mohamed; Dahlan Mohd
2014-01-01
Eletrospun non-woven fibre mats prepared from ENR modified PVC were successfully fabricated at ambient temperature by electro spinning method. Liquid epoxidized natural rubber (LENR) was used because it is easier to handle compared to dried ENR. PVC was mixed with LENR based on 3 different ratios (9:1, 8:2 and 7:3). The effect of ENR on electrospinnibality of PVC was investigated.The morphologies and thermal properties of the electro span fibre mats were characterized and assessed using scanning calorimetry (DSC). The polymer solution concentration 16 aut % formed a diameter of the fibres were mainly affected by the addition of natural rubber and weight ratio of the solution. The diameter of the fibres also decreased with increasing amount of LENR in the solution. Thermal degradation involved two-step degradation with the first degradation representing the dehydro chlorination of PVC to form polyene and followed by the decomposition of LENR and the polyene.Addition of LENR into the sample caused the T g of electro spun fibre mats of PVC/LENR to shift toward lower temperature. (author)
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Regulation of electron transfer processes affects phototrophic mat structure and activity
Ha, Phuc T.; Renslow, Ryan S.; Atci, Erhan; Reardon, Patrick N.; Lindemann, Stephen R.; Fredrickson, James K.; Call, Douglas R.; Beyenal, Haluk
2015-01-01
Phototrophic microbial mats are among the most diverse ecosystems in nature. These systems undergo daily cycles in redox potential caused by variations in light energy input and metabolic interactions among the microbial species. In this work, solid electrodes with controlled potentials were placed under mats to study the electron transfer processes between the electrode and the microbial mat. The phototrophic microbial mat was harvested from Hot Lake, a hypersaline, epsomitic lake located near Oroville (Washington, USA). We operated two reactors: graphite electrodes were polarized at potentials of -700 mVAg/AgCl [cathodic (CAT) mat system] and +300 mVAg/AgCl [anodic (AN) mat system] and the electron transfer rates between the electrode and mat were monitored. We observed a diel cycle of electron transfer rates for both AN and CAT mat systems. Interestingly, the CAT mats generated the highest reducing current at the same time points that the AN mats showed the highest oxidizing current. To characterize the physicochemical factors influencing electron transfer processes, we measured depth profiles of dissolved oxygen (DO) and sulfide in the mats using microelectrodes. We further demonstrated that the mat-to-electrode and electrode-to-mat electron transfer rates were light- and temperature-dependent. Using nuclear magnetic resonance (NMR) imaging, we determined that the electrode potential regulated the diffusivity and porosity of the microbial mats. Both porosity and diffusivity were higher in the CAT mats than in the AN mats. We also used NMR spectroscopy for high-resolution quantitative metabolite analysis and found that the CAT mats had significantly higher concentrations of osmoprotectants such as betaine and trehalose. Subsequently, we performed amplicon sequencing across the V4 region of the 16S rRNA gene of incubated mats to understand the impact of electrode potential on microbial community structure. These data suggested that variation in the
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Regulation of electron transfer processes affects phototrophic mat structure and activity
Directory of Open Access Journals (Sweden)
Haluk eBeyenal
2015-09-01
Full Text Available Phototrophic microbial mats are among the most diverse ecosystems in nature. These systems undergo daily cycles in redox potential caused by variations in light energy input and metabolic interactions among the microbial species. In this work, solid electrodes with controlled potentials were placed under mats to study the electron transfer processes between the electrode and the microbial mat. The phototrophic microbial mat was harvested from Hot Lake, a hypersaline, epsomitic lake located near Oroville (Washington, USA. We operated two reactors: graphite electrodes were polarized at potentials of -700 mVAg/AgCl (cathodic mat system and +300 mVAg/AgCl (anodic mat system and the electron transfer rates between the electrode and mat were monitored. We observed a diel cycle of electron transfer rates for both anodic and cathodic mat systems. Interestingly, the cathodic mats generated the highest reducing current at the same time points that the anodic mats showed the highest oxidizing current. To characterize the physicochemical factors influencing electron transfer processes, we measured depth profiles of dissolved oxygen and sulfide in the mats using microelectrodes. We further demonstrated that the mat-to-electrode and electrode-to-mat electron transfer rates were light- and temperature-dependent. Using nuclear magnetic resonance (NMR imaging, we determined that the electrode potential regulated the diffusivity and porosity of the microbial mats. Both porosity and diffusivity were higher in the cathodic mats than in the anodic mats. We also used NMR spectroscopy for high-resolution quantitative metabolite analysis and found that the cathodic mats had significantly higher concentrations of osmoprotectants such as betaine and trehalose. Subsequently, we performed amplicon sequencing across the V4 region of the 16S rRNA gene of incubated mats to understand the impact of electrode potential on microbial community structure. These data suggested that
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Regulation of electron transfer processes affects phototrophic mat structure and activity.
Ha, Phuc T; Renslow, Ryan S; Atci, Erhan; Reardon, Patrick N; Lindemann, Stephen R; Fredrickson, James K; Call, Douglas R; Beyenal, Haluk
2015-01-01
Phototrophic microbial mats are among the most diverse ecosystems in nature. These systems undergo daily cycles in redox potential caused by variations in light energy input and metabolic interactions among the microbial species. In this work, solid electrodes with controlled potentials were placed under mats to study the electron transfer processes between the electrode and the microbial mat. The phototrophic microbial mat was harvested from Hot Lake, a hypersaline, epsomitic lake located near Oroville (Washington, USA). We operated two reactors: graphite electrodes were polarized at potentials of -700 mVAg/AgCl [cathodic (CAT) mat system] and +300 mVAg/AgCl [anodic (AN) mat system] and the electron transfer rates between the electrode and mat were monitored. We observed a diel cycle of electron transfer rates for both AN and CAT mat systems. Interestingly, the CAT mats generated the highest reducing current at the same time points that the AN mats showed the highest oxidizing current. To characterize the physicochemical factors influencing electron transfer processes, we measured depth profiles of dissolved oxygen (DO) and sulfide in the mats using microelectrodes. We further demonstrated that the mat-to-electrode and electrode-to-mat electron transfer rates were light- and temperature-dependent. Using nuclear magnetic resonance (NMR) imaging, we determined that the electrode potential regulated the diffusivity and porosity of the microbial mats. Both porosity and diffusivity were higher in the CAT mats than in the AN mats. We also used NMR spectroscopy for high-resolution quantitative metabolite analysis and found that the CAT mats had significantly higher concentrations of osmoprotectants such as betaine and trehalose. Subsequently, we performed amplicon sequencing across the V4 region of the 16S rRNA gene of incubated mats to understand the impact of electrode potential on microbial community structure. These data suggested that variation in the
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Disruption of photoautotrophic intertidal mats by filamentous fungi
DEFF Research Database (Denmark)
Carreira, Cátia; Staal, Marc Jaap; Falkoski, Daniel
2015-01-01
Summary: Ring-like structures, 2.0-4.8cm in diameter, observed in photosynthetic microbial mats on the Wadden Sea island Schiermonnikoog (the Netherlands) showed to be the result of the fungus Emericellopsis sp. degrading the photoautotrophic top layer of the mat. The mats were predominantly comp...
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Emerson, D.; Rentz, J. A.; Moyer, C. L.
2005-12-01
The Loihi Seamount, located 30 km SE of the island of Hawai'i, is among the most active volcanos on Earth. The summit, at a depth of 1100m, includes a 250m deep caldera (Pele's Pit) formed by an eruption in 1996. The summit, and especially Pele's Pit, are the site of extensive low to intermediate temperature (10° to 65°C) hydrothermal venting, emanating both from diffuse fissures and orifices that have substantial flow rates. The vent fluid is characterized by a low sulfide content, high CO2 concentrations and Fe(II) amounts in the 10s to 100s of μM. Associated with all vents are extensive deposits of iron oxyhydroxides that typically have 107 to 108 bacterial cells/cc associated with them. The morphology of the Fe-oxides are indicative of biological origins. We have isolated microaerophilic, obligately lithotrophic Fe-oxidizing bacteria from Loihi and describe here `Mariprofundus ferroxydans' a unique bacterium that forms a filamentous iron oxide mineral. `M. ferroxydans' is the first cultured representative of a novel division of the Proteobacteria, known previously only from clones from different hydrothermal vent sites. Molecular evidence from Loihi mats based on clone libraries and terminal restriction length polymorphism (T-RFLP) analysis of 16S rRNA genes indicate that this lineage of Fe-oxidizing organisms are common inhabitants at Loihi. We speculate that this organism and its relatives form the basis of an active microbial mat community that owe their existence to the inherent gradients of Fe(II) and O2 that exist at the Loihi vents. In a geological context this is interesting because the Loihi summit and caldera are in an O2-minima zone; O2 concentrations in the bulk seawater are around 0.5 mg/l. In effect, Loihi could serve as a proxy for the late Archaean and early Proterozoic periods when the Earth's atmosphere went from reducing to oxidizing, and it is speculated that abundant Fe(II) in the Earth's oceans served as a major sink for O2 production
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Bebout, B.; Bebout, L. E.; Detweiler, A. M.; Everroad, R. C.; Lee, J.; Pett-Ridge, J.; Weber, P. K.
2014-12-01
Microbial mats are famously amongst the most diverse microbial ecosystems on Earth, inhabiting some of the most inclement environments known, including hypersaline, dry, hot, cold, nutrient poor, and high UV environments. The high microbial diversity of microbial mats makes studies of microbial ecology notably difficult. To address this challenge, we have been using a combination of metagenomics, metatranscriptomics, iTags and culture-based simplified microbial mats to study biogeochemical cycling (H2 production, N2 fixation, and fermentation) in microbial mats collected from Elkhorn Slough, Monterey Bay, California. Metatranscriptomes of microbial mats incubated over a diel cycle have revealed that a number of gene systems activate only during the day in Cyanobacteria, while the remaining appear to be constitutive. The dominant cyanobacterium in the mat (Microcoleus chthonoplastes) expresses several pathways for nitrogen scavenging undocumented in cultured strains, as well as the expression of two starch storage and utilization cycles. Community composition shifts in response to long term manipulations of mats were assessed using iTags. Changes in community diversity were observed as hydrogen fluxes increased in response to a lowering of sulfate concentrations. To produce simplified microbial mats, we have isolated members of 13 of the 15 top taxa from our iTag libraries into culture. Simplified microbial mats and simple co-cultures and consortia constructed from these isolates reproduce many of the natural patterns of biogeochemical cycling in the parent natural microbial mats, but against a background of far lower overall diversity, simplifying studies of changes in gene expression (over the short term), interactions between community members, and community composition changes (over the longer term), in response to environmental forcing.
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Sen, Syamal K.; Shaykhian, Gholam Ali
2011-01-01
MatLab(TradeMark)(MATrix LABoratory) is a numerical computation and simulation tool that is used by thousands Scientists and Engineers in many countries. MatLab does purely numerical calculations, which can be used as a glorified calculator or interpreter programming language; its real strength is in matrix manipulations. Computer algebra functionalities are achieved within the MatLab environment using "symbolic" toolbox. This feature is similar to computer algebra programs, provided by Maple or Mathematica to calculate with mathematical equations using symbolic operations. MatLab in its interpreter programming language form (command interface) is similar with well known programming languages such as C/C++, support data structures and cell arrays to define classes in object oriented programming. As such, MatLab is equipped with most of the essential constructs of a higher programming language. MatLab is packaged with an editor and debugging functionality useful to perform analysis of large MatLab programs and find errors. We believe there are many ways to approach real-world problems; prescribed methods to ensure foregoing solutions are incorporated in design and analysis of data processing and visualization can benefit engineers and scientist in gaining wider insight in actual implementation of their perspective experiments. This presentation will focus on data processing and visualizations aspects of engineering and scientific applications. Specifically, it will discuss methods and techniques to perform intermediate-level data processing covering engineering and scientific problems. MatLab programming techniques including reading various data files formats to produce customized publication-quality graphics, importing engineering and/or scientific data, organizing data in tabular format, exporting data to be used by other software programs such as Microsoft Excel, data presentation and visualization will be discussed.
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Les humains sont-ils des entités matérielles ?
Directory of Open Access Journals (Sweden)
Tauveron Matthias
2012-07-01
Full Text Available Nous étudions la sémantique des noms d’humains dans le lexique français. Dans la littérature, ces noms ont un positionnement indéterminé ou ambigu par rapport au critère concret/abstrait. Ce fait est regrettable car ce critère est considéré comme fondamental. Nous montrons leur positionnement particulier vis-à-vis de ce critère au travers de l’étude de métaphores attestées en corpus dans divers textes écrits. Nous suivons l’optique de Lakoff et Johnson en considérant que la métaphore est un révélateur des catégories de pensée. Dans cet esprit, la question est de savoir si les humains sont des entités matérielles ou non. L’étude est menée sur deux paramètres définitoires des entités matérielles : la masse et la spatialité. Nous apportons des caractérisations lexicales de ces deux propriétés. La masse est envisagée généralement, autour des noms, adjectifs et verbes relevés dans les dictionnaires. Nous proposons une synthèse des divers paramètres dénotant la spatialité dans la littérature, sous la forme de six points indépendants (forme, intérieur/extérieur, sous-parties, changement de posture, localisation, déplacement. L’étude de la spatialité est menée systématiquement dans ces directions grâce à des tests issus des caractérisations lexicales de ces aspects. Les tests font voir que, si les humains sont dotés d’une certaine dimension matérielle (qu’ils partagent ainsi avec les objets concrets, ils ont également au moins trois autres dimensions qui font qu’ils ne se réduisent pas à des objets matériels. Nous montrons ainsi que l’humain est, dans le lexique français, doté d’une multiplicité ontologique : en plus d’une dimension matérielle, il dispose d’une dimension psychologique, une dimension praxéologique et une dimension sociale. De plus, l’étude des métaphores montre que la dimension matérielle est souvent réduite voire anéantie par rapport aux
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Assembly and Succession of Iron Oxide Microbial Mat Communities in Acidic Geothermal Springs
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Jacob P. Beam
2016-02-01
Full Text Available Biomineralized ferric oxide microbial mats are ubiquitous features on Earth, are common in hot springs of Yellowstone National Park (YNP, WY, USA, and form due to direct interaction between microbial and physicochemical processes. The overall goal of this study was to determine the contribution of different community members to the assembly and succession of acidic high-temperature Fe(III-oxide mat ecosystems. Spatial and temporal changes in Fe(III-oxide accretion and the abundance of relevant community members were monitored over 70 days using sterile glass microscope slides incubated in the outflow channels of two acidic geothermal springs (pH = 3 - 3.5; temperature = 68 - 75 °C in YNP. Hydrogenobaculum spp. were the most abundant taxon identified during early successional stages (4 - 40 d, and have been shown to oxidize arsenite, sulfide, and hydrogen coupled to oxygen reduction. Iron-oxidizing populations of Metallosphaera yellowstonensis were detected within 4 d, and reached steady-state levels within 14 - 30 d, corresponding to visible Fe(III-oxide accretion. Heterotrophic archaea colonized near 30 d, and emerged as the dominant functional guild after 70 d and in mature Fe(III-oxide mats (1 - 2 cm thick. First-order rate constants of Fe(III-oxide accretion ranged from 0.046 - 0.05 d-1, and in situ microelectrode measurements showed that the oxidation of Fe(II is limited by the diffusion of O2 into the Fe(III-oxide mat. The formation of microterracettes also implicated O2 as a major variable controlling microbial growth and subsequent mat morphology. The assembly and succession of Fe(III-oxide mat communities follows a repeatable pattern of colonization by lithoautotrophic organisms, and the subsequent growth of diverse organoheterotrophs. The unique geochemical signatures and micromorphology of extant biomineralized Fe(III-oxide mats are useful for understanding other Fe(II-oxidizing systems.
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HiRadMat: materials under scrutiny
Anaïs Schaeffer
2011-01-01
CERN's new facility, HiRadMat (High Radiation to Materials), which is designed to test materials for the world's future particle accelerators, should be operational and welcoming its first experiments by the end of the year. The HiRadMat facility, located in the TNC tunnel. The materials used in the LHC and its experiments are exposed to very high-energy particles. The LHC machine experts obviously didn't wait for the first collisions in the world's most powerful accelerator to put the materials through their paces - the equipment was validated following a series of stringent tests. And these tests will get even tougher now, with the arrival of HiRadMat. The tunnel that formerly housed the West Area Neutrino Facility (WANF) has been completely revamped to make way for CERN's latest facility, HiRadMat. Supported by the Radioprotection service, a team from the Engineering (EN) Department handled the dismantling operations from October 2009 to December 2010. "We could only work on disman...
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Reefs under Siege—the Rise, Putative Drivers, and Consequences of Benthic Cyanobacterial Mats
Directory of Open Access Journals (Sweden)
Amanda K. Ford
2018-02-01
Full Text Available Benthic cyanobacteria have commonly been a small but integral component of coral reef ecosystems, fulfilling the critical function of introducing bioavailable nitrogen to an inherently oligotrophic environment. Though surveys may have previously neglected benthic cyanobacteria, or grouped them with more conspicuous benthic groups, emerging evidence strongly indicates that they are becoming increasingly prevalent on reefs worldwide. Some species can form mats comprised by a diverse microbial consortium which allows them to exist across a wide range of environmental conditions. This review evaluates the putative driving factors of increasing benthic cyanobacterial mats, including climate change, declining coastal water quality, iron input, and overexploitation of key consumer and ecosystem engineer species. Ongoing global environmental change can increase growth rates and toxin production of physiologically plastic benthic cyanobacterial mats, placing them at a considerable competitive advantage against reef-building corals. Once established, strong ecological feedbacks [e.g., inhibition of coral recruitment, release of dissolved organic carbon (DOC] reinforce reef degradation. The review also highlights previously overlooked implications of mat proliferation, which can extend beyond reef health and affect human health and welfare. Though identifying (opportunistic consumers of mats remains a priority, their perceived low palatability implies that herbivore management alone may be insufficient to control their proliferation and must be accompanied by local measures to improve water quality and watershed management.
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Energy Technology Data Exchange (ETDEWEB)
Ziervogel, H.; Selann, J.; Adeney, B. [EBA Engineering Consultants Ltd., Edmonton, AB (Canada); Nelson, J.A. [J.B. Services, Sarnia, ON (Canada); Murdock, E. [Nunavut Power, Iqaluit (Canada)
2003-07-01
An environmental assessment conducted at Repulse Bay, Nunavut in the summer of 2001 revealed a recent diesel spill flowing from the groundwater into a creek. The spill had not been reported. When Arctic surface waters mix with hydrocarbon impacted groundwater and sediments, distinctive mats of diatom, cyanobacteria and other bacteria are formed. These mats have the potential for phytoremediation of hydrocarbons. This paper explained the apparent dominance of mats in contaminated Arctic waters and why they promote biodegradation of hydrocarbons. Hydrocarbon-contaminated soils and groundwater are generally anaerobic. The higher dissolved carbon dioxide in polluted soils and groundwater can benefit photosynthetic cyanobacteria and diatom found in oligotrophic, lower alkalinity Arctic waters. The anaerobic and aerobic bacteria can potentially take advantage of the hydrogen substrate and the nitrogen fixing abilities of the cyanobacteria. Zooplankton predators may be killed off by the toxicity of the polluted groundwater. The paper provides examples where a microbial mat reduced the sulfate content of a hydrocarbon-impacted Arctic stream by 100 ppm, and where a pond covered in a benthic microbial mat showed no evidence of hydrocarbons in the water overlying sediments contaminated with hydrocarbons at concentrations measured at 30,000 ppm. 19 refs., 3 tabs., 8 figs.
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Rapid spectrofluorometric screening of poly-hydroxyalkanoate-producing bacteria from microbial mats.
Berlanga, Mercedes; Montero, M T; Fernández-Borrell, Jordi; Guerrero, Ricardo
2006-06-01
Microbial mat ecosystems are characterized by both seasonal and diel fluctuations in several physicochemical variables, so that resident microorganisms must frequently adapt to the changing conditions of their environment. It has been pointed out that, under stress conditions, bacterial cells with higher contents of poly-hydroxyalkanoates (PHA) survive longer than those with lower PHA content. In the present study, PHA-producing strains from Ebro Delta microbial mats were selected using the Nile red dying technique and the relative accumulation of PHA was monitored during further laboratory cultivation. The number of heterotrophic isolates in trypticase soy agar (TSA) was ca. 107 colony-forming units/g microbial mat. Of these, 100 randomly chosen colonies were replicated on mineral salt agar limited in nitrogen, and Nile red was added to the medium to detect PHA. Orange fluorescence, produced upon binding of the dye to polymer granules in the cell, was detected in approximately 10% of the replicated heterotrophic isolates. The kinetics of PHA accumulation in Pseudomonas putida, and P. oleovorans were compared with those of several of the environmental isolates spectrofluorometry. PHA accumulation, measured as relative fluorescence intensity, resulted in a steady-state concentration after 48 h of incubation in all strains assayed. At 72 h, the maximum fluorescence intensity of each strain incubated with glucose and fructose was usually similar. MAT-28 strain accumulated more PHA than the other isolates. The results show that data obtained from environmental isolates can highly improve studies based on modeling-simulation programs, and that microbial mats constitute an excellent source for the isolation of PHA-producing strains with industrial applications.
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Dalyander, P. Soupy; Long, Joseph W.; Plant, Nathaniel G.; Thompson, David M.
2013-01-01
During the Deepwater Horizon oil spill, oil in the surf zone mixed with sediment in the surf zone to form heavier-than-water sediment oil agglomerates of various size, ranging from small (cm-scale) pieces (surface residual balls, SRBs) to large mats (100-m scale, surface residue mats, SR mats). Once SR mats formed in the nearshore or in the intertidal zone, they may have become buried by sand moving onshore or alongshore. To assist in locating possible sites of buried oil, wave scenarios previously developed by the U.S. Geological Survey (USGS) were used to determine the depths at which surface oil had the potential to mix with suspended sediment. For sediment to mix with floating oil and form an agglomerate of sufficient density to sink to the seafloor, either the water must be very shallow (e.g., within the swash zone) or sediment must be suspended to the water surface in sufficient concentrations to create a denser-than-sea water agglomerate. The focus of this study is to analyze suspended sediment mixing with surface oil in depths beyond the swash zone, in order to define the seaward limit of mat formation. A theoretical investigation of sediment dynamics in the nearshore zone revealed that non-breaking waves do not suspend enough sediment to the surface to form sinking sand/oil agglomerates. For this study, it was assumed that the cross-shore distribution of potential agglomerate formation is associated with the primary breaker line, and the presence of plunging breakers, over the time frame of oiling. The potential locations of submerged oil mats (SOMs) are sites where (1) possible agglomerate formation occurred, where (2) sediment accreted post-oiling and buried the SOM, and where (3) the bathymetry has not subsequently eroded to re-expose any mat that may have formed at that site. To facilitate identification of these locations, the range of water level variation over the time frame of oiling was also prescribed, which combined with the wave-breaking depth
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Effects of preprocessing method on TVOC emission of car mat
Wang, Min; Jia, Li
2013-02-01
The effects of the mat preprocessing method on total volatile organic compounds (TVOC) emission of car mat are studied in this paper. An appropriate TVOC emission period for car mat is suggested. The emission factors for total volatile organic compounds from three kinds of new car mats are discussed. The car mats are preprocessed by washing, baking and ventilation. When car mats are preprocessed by washing, the TVOC emission for all samples tested are lower than that preprocessed in other methods. The TVOC emission is in stable situation for a minimum of 4 days. The TVOC emitted from some samples may exceed 2500μg/kg. But the TVOC emitted from washed Polyamide (PA) and wool mat is less than 2500μg/kg. The emission factors of total volatile organic compounds (TVOC) are experimentally investigated in the case of different preprocessing methods. The air temperature in environment chamber and the water temperature for washing are important factors influencing on emission of car mats.
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Biddanda, Bopaiah A.; McMillan, Adam C.; Long, Stephen A.; Snider, Michael J.; Weinke, Anthony D.
2015-01-01
We studied the motility of filamentous mat-forming cyanobacteria consisting primarily of Oscillatoria-like cells growing under low-light, low-oxygen, and high-sulfur conditions in Lake Huron’s submerged sinkholes using in situ observations, in vitro measurements and time-lapse microscopy. Gliding movement of the cyanobacterial trichomes (100–10,000 μm long filaments, composed of cells ∼10 μm wide and ∼3 μm tall) revealed individual as well as group-coordinated motility. When placed in a petri dish and dispersed in ground water from the sinkhole, filaments re-aggregated into defined colonies within minutes, then dispersed again. Speed of individual filaments increased with temperature from ∼50 μm min-1 or ∼15 body lengths min-1 at 10°C to ∼215 μm min-1 or ∼70 body lengths min-1 at 35°C – rates that are rapid relative to non-flagellated/ciliated microbes. Filaments exhibited precise and coordinated positive phototaxis toward pinpoints of light and congregated under the light of foil cutouts. Such light-responsive clusters showed an increase in photosynthetic yield – suggesting phototactic motility aids in light acquisition as well as photosynthesis. Once light source was removed, filaments slowly spread out evenly and re-aggregated, demonstrating coordinated movement through inter-filament communication regardless of light. Pebbles and pieces of broken shells placed upon intact mat were quickly covered by vertically motile filaments within hours and became fully buried in the anoxic sediments over 3–4 diurnal cycles – likely facilitating the preservation of falling debris. Coordinated horizontal and vertical filament motility optimize mat cohesion and dynamics, photosynthetic efficiency and sedimentary carbon burial in modern-day sinkhole habitats that resemble the shallow seas in Earth’s early history. Analogous cyanobacterial motility may have played a key role in the oxygenation of the planet by optimizing photosynthesis while
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Directory of Open Access Journals (Sweden)
Piotr Balazy
2014-06-01
Full Text Available We report the first observation of large red cyanobacterial mats in the southern Baltic Sea. The mats (up to 2.5 m in diameter were observed by SCUBA divers at 7.7 m depth on loamy sediments in the Gulf of Gdańsk in mid-November 2013. The main structure of the mat was formed by cyanobacteria Spirulina subsalsa Oersted ex Gomont; a number of other cyanobacteria, diatoms and nematode species were also present. After a few days in the laboratory, the red trichomes of S. subsalsa started to turn blue-green in colour, suggesting the strong chromatic acclimation abilities of this species.
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Development of kenaf mat for slope stabilization
Ahmad, M. M.; Manaf, M. B. H. Ab; Zainol, N. Z.
2017-09-01
This study focusing on the ability of kenaf mat to act as reinforcement to laterite compared to the conventional geosynthetic in term of stabilizing the slope. Kenaf mat specimens studied in this paper are made up from natural kenaf fiber with 3mm thickness, 150mm length and 20mm width. With the same size of specimens, geosynthetic that obtain from the industry are being tested for both direct shear and tensile tests. Plasticity index of the soil sample used is equal to 13 which indicate that the soil is slightly plastic. Result shows that the friction angle of kenaf mat is higher compared to friction between soil particles itself. In term of resistance to tensile load, the tensile strength of kenaf mat is 0.033N/mm2 which is lower than the tensile strength of geosynthetic.
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Physical and Mechanical Properties of Jute Mat Reinforced Epoxy Composites
Directory of Open Access Journals (Sweden)
S.M Sadaf
2011-11-01
Full Text Available Cellulose jute fibre offers a number of benefits as reinforcement for synthetic polymers since it has a high specific strength and stiffness, low hardness, relatively low density and biodegradability. To reduce moisture uptake and hence to improve the mechanical properties of the composites, bleached jute mats were incorporated as reinforcing elements in the epoxy matrix. Composites at varying volume fractions and different orientations of jute mat were fabricated by hot compression machine under specific pressures and temperatures. Tensile, flexure, impact and water absorption tests of composites were conducted. Jute mat oriented at (0 ± 45–90° composites showed reduced strength compared to (0–90° fibre mat composites. Impact strength and water uptake of high volume fraction jute mat reinforced composites was higher compared to that of lower volume fraction composites. Fracture surfaces of jute mat composites were analyzed under SEM. Fracture surface of (0–90° jute mat oriented composites showed twisted fibres, while (0 ± 45–90° jute mat oriented composites had fibre pull-out without any twisting. Overall, composites containing 52% jute mat at orientations of (0–90° showed better properties compared to other fabricated composites.
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ENGUENG,; ABIB,
2009-01-01
ViscoMatData est un logiciel extranet d'une gestion d'une base de données multilingue sur les propriétés des matériaux viscoélastiques des chaussées. Ce rapport constitue l'un des livrables de la deuxième partie de ce projet. Pour présenter le travail réalisé durant cette deuxième partie, nous commencerons par faire un rappel sur le contexte du projet et le projet et le projet lui-même. Puis, nous nous intéresserons à l'architecture mise en place pour le développement, la réalisation et nous ...
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Wood, Susanna A; Smith, Francine M J; Heath, Mark W; Palfroy, Thomas; Gaw, Sally; Young, Roger G; Ryan, Ken G
2012-10-01
Benthic Phormidium mats can contain high concentrations of the neurotoxins anatoxin-a and homoanatoxin-a. However, little is known about the co-occurrence of anatoxin-producing and non-anatoxin-producing strains within mats. There is also no data on variation in anatoxin content among toxic genotypes isolated from the same mat. In this study, 30 Phormidium strains were isolated from 1 cm(2) sections of Phormidium-dominated mats collected from three different sites. Strains were grown to stationary phase and their anatoxin-a, homoanatoxin-a, dihydroanatoxin-a and dihydrohomoanatoxin-a concentrations determined using liquid chromatography-mass spectrometry. Each strain was characterized using morphological and molecular (16S rRNA gene sequences) techniques. Eighteen strains produced anatoxin-a, dihydroanatoxin-a or homoanatoxin-a. Strains isolated from each mat either all produced toxins, or were a mixture of anatoxin and non-anatoxin-producing genotypes. Based on morphology these genotypes could not be separated. The 16S rRNA gene sequence comparisons showed a difference of at least 17 nucleotides among anatoxin and non-anatoxin-producing strains and these formed two separate sub-clades during phylogenetic analysis. The total anatoxin concentration among toxic strains varied from 2.21 to 211.88 mg kg(-1) (freeze dried weight), representing a 100 fold variation in toxin content. These data indicate that both the relative abundance of anatoxin and non-anatoxin-producing genotypes, and variations in anatoxin producing capability, can influence the overall toxin concentration of benthic Phormidium mat samples.
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Iniesto, Miguel; Zeyen, Nina; López-Archilla, Ana; Bernard, Sylvain; Buscalioni, Ángela; Guerrero, M. Carmen; Benzerara, Karim
2015-09-01
Microbial mats have been repeatedly suggested to promote early fossilization of macroorganisms. Yet, experimental simulations of this process remain scarce. Here, we report results of 5 year-long experiments performed onfish carcasses to document the influence of microbial mats on mineral precipitation during early fossilization. Carcasses were initially placed on top of microbial mats. After two weeks, fishes became coated by the mats forming a compact sarcophagus, which modified the microenvironment close to the corpses. Our results showed that these conditions favoured the precipitation of a poorly crystalline silicate phase rich in magnesium. This talc-like mineral phase has been detected in three different locations within the carcasses placed in microbial mats for more than 4 years: 1) within inner tissues, colonized by several bacillary cells; 2) at the surface of bones of the upper face of the corpse buried in the mat; and 3) at the surface of several bones such as the dorsal fin which appeared to be gradually replaced by the Mg-silicate phase. This mineral phase has been previously shown to promote bacteria fossilization. Here we provide first experimental evidence that such Mg-rich phase can also be involved in exceptional preservation of animals.
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Beaded Fiber Mats of PVA Containing Unsaturated Heteropoly Salt
Institute of Scientific and Technical Information of China (English)
Guo Cheng YANG; Yan PAN; Jian GONG; Chang Lu SHAO; Shang Bin WEN; Chen SHAO; Lun Yu QU
2004-01-01
Poly(vinyl alcohol) (PVA) fiber mats containing unsaturated heteropoly salt was prepared for the first time. IR, X-ray diffraction and SEM photographs characterized the beaded fiber mats.The viscoelasticity and the conductivity of the solution were the key factors that influence the formation of the beaded fiber mats.
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Two-step activation of meiosis by the mat1 locus in Schizosaccharomyces pombe
DEFF Research Database (Denmark)
Willer, M; Hoffmann, Ulla-Lisbeth; Styrkársdóttir, U
1995-01-01
in which the mat1 locus plays two roles in controlling meiosis. In the first instance, the mat1-Pc and mat1-Mc functions are required to produce the mating pheromones and receptors that allow the generation of a pheromone signal. This signal is required to induce the expression of mat1-Pm and mat1-Mm......The mat1 locus is a key regulator of both conjugation and meiosis in the fission yeast Schizosaccharomyces pombe. Two alternative DNA segments of this locus, mat1-P and mat1-M, specify the haploid cell types (Plus and Minus). Each segment includes two genes: mat1-P includes mat1-Pc and mat1-Pm....... This appears to be the major pheromone-dependent step in controlling meiosis since ectopic expression of these genes allows meiosis in the absence of mat1-Pc and mat1-Mc. The mat1-Pm and mat1-Mm products complete the initiation of meiosis by activating transcription of the mei3 gene....
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Bolukbas, Cengiz; Bolukbas, Fusun Filiz; Horoz, Mehmet; Aslan, Mehmet; Celik, Hakim; Erel, Ozcan
2005-10-31
Oxidative stress can be defined as an increase in oxidants and/or a decrease in antioxidant capacity. There is limited information about the oxidative status in subjects with hepatitis B virus infection. We aimed to evaluate the oxidative status in patients with various clinical forms of chronic hepatitis B infection. Seventy-six patients with hepatitis B virus infection, in whom 33 with chronic hepatitis, 31 inactive carriers and 12 with cirrhosis, and 16 healthy subjects were enrolled. Total antioxidant response and total peroxide level measurement, and calculation of oxidative stress index were performed in all participants. Total antioxidant response was significantly lower in cirrhotics than inactive HbsAg carriers and controls (p = 0.008 and p = 0.008, respectively). Total peroxide level and oxidative stress index was significantly higher in cirrhotic (p Total antioxidant response was comparable in chronic hepatitis B subjects, inactive HbsAg carriers and controls (both, p > 0.05/6). Total peroxide level and oxidative stress index were also comparable in inactive HBsAg carriers and controls (both, p > 0.05/6). Serum alanine amino transferase level was positively correlated with total peroxide level and oxidative stress index only in chronic hepatitis B subjects (p = 0.002, r = 0.519 and p = 0.008, r = 0.453, respectively). Oxidative stress occurs secondarily to increased total lipid peroxidation and inadequate total antioxidant response and is related to severity of the disease and replication status of virus in hepatitis B infection.
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Polycaprolactone-Chitin Nanofibrous Mats as Potential Scaffolds for Tissue Engineering
Directory of Open Access Journals (Sweden)
Min Sup Kim
2012-01-01
Full Text Available We describe here the preparation of poly(caprolactone (PCL-chitin nanofibrous mats by electrospinning from a blended solution of PCL and chitin dissolved in a cosolvent, 1,1,1,3,3,3-hexafluoro-2-propanol and trifluoroacetic acid. Scanning electron microscopy showed that the neutralized PCL-chitin nanofibrous mats were morphologically stable, with a mean diameter of 340.5±2.6 nm, compared with a diameter of 524.2±12.1 nm for PCL mats. The nanofibrous mats showed decreased water contact angles as the proportion of chitin increased. However, the tensile properties of nanofibrous mats containing 30~50% (wt/wt chitin were enhanced compared with PCL-only mats. In vitro studies showed that the viability of human dermal fibroblasts (HDFs for up to 7 days in culture was higher on composite (OD value: 1.42±0.09 than on PCL-only (0.51±0.14 nanofibrous mats, with viability correlated with chitin concentration. Together, our results suggest that PCL-chitin nanofibrous mats can be used as an implantable substrate to modulate HDF viability in tissue engineering.
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Microbial communities and exopolysaccharides from Polynesian mats.
Rougeaux, H; Guezennec, M; Che, L M; Payri, C; Deslandes, E; Guezennec, J
2001-03-01
Microbial mats present in two shallow atolls of French Polynesia were characterized by high amounts of exopolysaccharides associated with cyanobacteria as the predominating species. Cyanobacteria were found in the first centimeters of the gelatinous mats, whereas deeper layers showing the occurrence of the sulfate reducers Desulfovibrio and Desulfobacter species as determined by the presence of specific biomarkers. Exopolysaccharides were extracted from these mats and partially characterized. All fractions contained both neutral sugars and uronic acids with a predominance of the former. The large diversity in monosaccharides can be interpreted as the result of exopolymer biosynthesis by either different or unidentified cyanobacterial species.
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Energy Technology Data Exchange (ETDEWEB)
Ruvindy, Rendy; White III, Richard Allen; Neilan, Brett Anthony; Burns, Brendan Paul
2015-05-29
Modern microbial mats are potential analogues of some of Earth’s earliest ecosystems. Excellent examples can be found in Shark Bay, Australia, with mats of various morphologies. To further our understanding of the functional genetic potential of these complex microbial ecosystems, we conducted for the first time shotgun metagenomic analyses. We assembled metagenomic nextgeneration sequencing data to classify the taxonomic and metabolic potential across diverse morphologies of marine mats in Shark Bay. The microbial community across taxonomic classifications using protein-coding and small subunit rRNA genes directly extracted from the metagenomes suggests that three phyla Proteobacteria, Cyanobacteria and Bacteriodetes dominate all marine mats. However, the microbial community structure between Shark Bay and Highbourne Cay (Bahamas) marine systems appears to be distinct from each other. The metabolic potential (based on SEED subsystem classifications) of the Shark Bay and Highbourne Cay microbial communities were also distinct. Shark Bay metagenomes have a metabolic pathway profile consisting of both heterotrophic and photosynthetic pathways, whereas Highbourne Cay appears to be dominated almost exclusively by photosynthetic pathways. Alternative non-rubisco-based carbon metabolism including reductive TCA cycle and 3-hydroxypropionate/4-hydroxybutyrate pathways is highly represented in Shark Bay metagenomes while not represented in Highbourne Cay microbial mats or any other mat forming ecosystems investigated to date. Potentially novel aspects of nitrogen cycling were also observed, as well as putative heavy metal cycling (arsenic, mercury, copper and cadmium). Finally, archaea are highly represented in Shark Bay and may have critical roles in overall ecosystem function in these modern microbial mats.
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Developing DNA barcoding (matK) primers for marama bean ...
African Journals Online (AJOL)
The homology found with Tylosema fassoglensis (trnK gene) and Pisum sativum (matK gene) suggests that an identical region was amplified for Tylosema esculentum. A phylogenetic tree was constructed based on the matK sequences and the results suggest that the matK region can also be used in determining levels of ...
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Nanofiber electrode and method of forming same
Energy Technology Data Exchange (ETDEWEB)
Pintauro, Peter N.; Zhang, Wenjing
2018-02-27
In one aspect, a method of forming an electrode for an electrochemical device is disclosed. In one embodiment, the method includes the steps of mixing at least a first amount of a catalyst and a second amount of an ionomer or uncharged polymer to form a solution and delivering the solution into a metallic needle having a needle tip. The method further includes the steps of applying a voltage between the needle tip and a collector substrate positioned at a distance from the needle tip, and extruding the solution from the needle tip at a flow rate such as to generate electrospun fibers and deposit the generated fibers on the collector substrate to form a mat with a porous network of fibers. Each fiber in the porous network of the mat has distributed particles of the catalyst. The method also includes the step of pressing the mat onto a membrane.
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Diversity and stratification of archaea in a hypersaline microbial mat.
Robertson, Charles E; Spear, John R; Harris, J Kirk; Pace, Norman R
2009-04-01
The Guerrero Negro (GN) hypersaline microbial mats have become one focus for biogeochemical studies of stratified ecosystems. The GN mats are found beneath several of a series of ponds of increasing salinity that make up a solar saltern fed from Pacific Ocean water pumped from the Laguna Ojo de Liebre near GN, Baja California Sur, Mexico. Molecular surveys of the laminated photosynthetic microbial mat below the fourth pond in the series identified an enormous diversity of bacteria in the mat, but archaea have received little attention. To determine the bulk contribution of archaeal phylotypes to the pond 4 study site, we determined the phylogenetic distribution of archaeal rRNA gene sequences in PCR libraries based on nominally universal primers. The ratios of bacterial/archaeal/eukaryotic rRNA genes, 90%/9%/1%, suggest that the archaeal contribution to the metabolic activities of the mat may be significant. To explore the distribution of archaea in the mat, sequences derived using archaeon-specific PCR primers were surveyed in 10 strata of the 6-cm-thick mat. The diversity of archaea overall was substantial albeit less than the diversity observed previously for bacteria. Archaeal diversity, mainly euryarchaeotes, was highest in the uppermost 2 to 3 mm of the mat and decreased rapidly with depth, where crenarchaeotes dominated. Only 3% of the sequences were specifically related to known organisms including methanogens. While some mat archaeal clades corresponded with known chemical gradients, others did not, which is likely explained by heretofore-unrecognized gradients. Some clades did not segregate by depth in the mat, indicating broad metabolic repertoires, undersampling, or both.
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Targeting S-adenosylmethionine biosynthesis with a novel allosteric inhibitor of Mat2A
Energy Technology Data Exchange (ETDEWEB)
Quinlan, Casey L.; Kaiser, Stephen E.; Bolaños, Ben; Nowlin, Dawn; Grantner, Rita; Karlicek-Bryant, Shannon; Feng, Jun Li; Jenkinson, Stephen; Freeman-Cook, Kevin; Dann, Stephen G.; Wang, Xiaoli; Wells, Peter A.; Fantin, Valeria R.; Stewart, Al E.; Grant, Stephan K. (Pfizer)
2017-05-29
S-Adenosyl-L-methionine (SAM) is an enzyme cofactor used in methyl transfer reactions and polyamine biosynthesis. The biosynthesis of SAM from ATP and L-methionine is performed by the methionine adenosyltransferase enzyme family (Mat; EC 2.5.1.6). Human methionine adenosyltransferase 2A (Mat2A), the extrahepatic isoform, is often deregulated in cancer. We identified a Mat2A inhibitor, PF-9366, that binds an allosteric site on Mat2A that overlaps with the binding site for the Mat2A regulator, Mat2B. Studies exploiting PF-9366 suggested a general mode of Mat2A allosteric regulation. Allosteric binding of PF-9366 or Mat2B altered the Mat2A active site, resulting in increased substrate affinity and decreased enzyme turnover. These data support a model whereby Mat2B functions as an inhibitor of Mat2A activity when methionine or SAM levels are high, yet functions as an activator of Mat2A when methionine or SAM levels are low. The ramification of Mat2A activity modulation in cancer cells is also described.
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MatLab Programming for Engineers Having No Formal Programming Knowledge
Shaykhian, Linda H.; Shaykhian, Gholam Ali
2007-01-01
MatLab is one of the most widely used very high level programming languages for Scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems. Specifically provided are programs for visualization. Also, stated are the current limitations of the MatLab, which possibly can be taken care of by Mathworks Inc. in a future version to make MatLab more versatile.
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Parsekian, A.D.; Jones, Benjamin M.; Jones, M.; Grosse, G.; Walter, Anthony K.M.; Slater, L.
2011-01-01
Investigations on the northern Seward Peninsula in Alaska identified zones of recent (<50years) permafrost collapse that led to the formation of floating vegetation mats along thermokarst lake margins. The occurrence of floating vegetation mat features indicates rapid degradation of near-surface permafrost and lake expansion. This paper reports on the recent expansion of these collapse features and their geometry is determined using geophysical and remote sensing measurements. The vegetation mats were observed to have an average thickness of 0.57m and petrophysical modeling indicated that gas content of 1.5-5% enabled floatation above the lake surface. Furthermore, geophysical investigation provides evidence that the mats form by thaw and subsidence of the underlying permafrost rather than terrestrialization. The temperature of the water below a vegetation mat was observed to remain above freezing late in the winter. Analysis of satellite and aerial imagery indicates that these features have expanded at maximum rates of 1-2myr-1 over a 56year period. Including the spatial coverage of floating 'thermokarst mats' increases estimates of lake area by as much as 4% in some lakes. ?? 2011 John Wiley & Sons, Ltd.
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Severin, I.; Stal, L.J.; Seckbach, J.; Oren, A.
2010-01-01
Microbial mats have been the focus of scientific research for a few decades. These small-scale ecosystems are examples of versatile benthic communities of microorganisms, usually dominated by phototrophic bacteria (e.g., Krumbein et al., 1977; Jørgensen et al., 1983). They develop as vertically
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Method for production of carbon nanofiber mat or carbon paper
Naskar, Amit K.
2015-08-04
Method for the preparation of a non-woven mat or paper made of carbon fibers, the method comprising carbonizing a non-woven mat or paper preform (precursor) comprised of a plurality of bonded sulfonated polyolefin fibers to produce said non-woven mat or paper made of carbon fibers. The preforms and resulting non-woven mat or paper made of carbon fiber, as well as articles and devices containing them, and methods for their use, are also described.
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Parsekian, A.D.; Jones, Benjamin M.; Jones, M.; Grosse, G.; Walter, Anthony K.M.; Slater, L.
2011-01-01
Investigations on the northern Seward Peninsula in Alaska identified zones of recent (geometry is determined using geophysical and remote sensing measurements. The vegetation mats were observed to have an average thickness of 0.57m and petrophysical modeling indicated that gas content of 1.5-5% enabled floatation above the lake surface. Furthermore, geophysical investigation provides evidence that the mats form by thaw and subsidence of the underlying permafrost rather than terrestrialization. The temperature of the water below a vegetation mat was observed to remain above freezing late in the winter. Analysis of satellite and aerial imagery indicates that these features have expanded at maximum rates of 1-2myr-1 over a 56year period. Including the spatial coverage of floating 'thermokarst mats' increases estimates of lake area by as much as 4% in some lakes. ?? 2011 John Wiley & Sons, Ltd.
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Paul, Andreas; Lessa Andrade, Luiza; Dutton, Kirsten E.; Sherry, Angela; Court, Wesley M.; Van der Land, Cees; Lokier, Stephen W.; Head, Ian M.
2017-04-01
Stromatolitic features are documented from both marine and terrestrial environments worldwide. These features form through a combination of trapping and binding of allochthonous grains, and through microbially mediated and/or controlled precipitation of carbonate minerals. The combined effects of these processes result in the continuous vertical and lateral growth of stromatolites. While the Abu Dhabi coastal sabkha is well known for a vast microbial mat belt that is dominated by continuous polygonal and internally-laminated microbial mats, no stromatolitic features have been reported from this area so far. In this study, we report evidence for stromatolitic features from the coastal sabkha of Abu Dhabi, based on observations in an intertidal but permanently submerged pool. This pool lies embedded within the laminated microbial mat zone, and is marked by the development of true laminated stromatolite at its margins and microbial build-ups at its centre. In order to characterise processes that lead to the formation of these stromatolitic features, and to develop a conceptual model that describes their development in the context of variations in sea level, tidal energy and other environmental factors, we employ a multitude of environmental, sedimentological, mineralogical and geochemical methods. These methods include the analysis of water data in terms of temporal variations in temperature, salinity, dissolved oxygen and water level, the analysis of petrographic thin sections of both lithified and unlithified features as well as an analysis of the stromatolites' mineralogical composition, and the amounts of incorporated organic carbon and calcium carbonate. Initial results suggest that the development of the observed stromatolitic features in the coastal sabkha of Abu Dhabi is the result of a complex interplay between simultaneous erosion of laminated microbial mat, and biotic/abiotic lithification processes. Initially, the location of this pool was characterised by
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Hongmei, Jing; Aitchison, Jonathan C; Lacap, Donnabella C; Peerapornpisal, Yuwadee; Sompong, Udomluk; Pointing, Stephen B
2005-08-01
Most community molecular studies of thermophilic cyanobacterial mats to date have focused on Synechococcus occurring at temperatures of approximately 50-65 degrees C. These reveal that molecular diversity exceeds that indicated by morphology, and that phylogeographic lineages exist. The moderately thermophilic and generally filamentous cyanobacterial mat communities occurring at lower temperatures have not previously been investigated at the community molecular level. Here we report community diversity in mats of 42-53 degrees C recovered from previously unstudied geothermal locations. Separation of 16S rRNA gene-defined genotypes from community DNA was achieved by DGGE. Genotypic diversity was greater than morphotype diversity in all mats sampled, although genotypes generally corresponded to observed morphotypes. Thirty-six sequences were recovered from DGGE bands. Phylogenetic analyses revealed these to form novel thermophilic lineages distinct from their mesophilic counterparts, within Calothrix, Cyanothece, Fischerella, Phormidium, Pleurocapsa, Oscillatoria and Synechococcus. Where filamentous cyanobacterial sequences belonging to the same genus were recovered from the same site, these were generally closely affiliated. Location-specific sequences were observed for some genotypes recovered from geochemically similar yet spatially separated sites, thus providing evidence for phylogeographic lineages that evolve in isolation. Other genotypes were more closely affiliated to geographically remote counterparts from similar habitats suggesting that adaptation to certain niches is also important.
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Directory of Open Access Journals (Sweden)
Aslan Mehmet
2005-10-01
Full Text Available Abstract Background Oxidative stress can be defined as an increase in oxidants and/or a decrease in antioxidant capacity. There is limited information about the oxidative status in subjects with hepatitis B virus infection. We aimed to evaluate the oxidative status in patients with various clinical forms of chronic hepatitis B infection. Methods Seventy-six patients with hepatitis B virus infection, in whom 33 with chronic hepatitis, 31 inactive carriers and 12 with cirrhosis, and 16 healthy subjects were enrolled. Total antioxidant response and total peroxide level measurement, and calculation of oxidative stress index were performed in all participants. Results Total antioxidant response was significantly lower in cirrhotics than inactive HbsAg carriers and controls (p = 0.008 and p = 0.008, respectively. Total peroxide level and oxidative stress index was significantly higher in cirrhotic (p 0.05/6. Total peroxide level and oxidative stress index were also comparable in inactive HBsAg carriers and controls (both, p > 0.05/6. Serum alanine amino transferase level was positively correlated with total peroxide level and oxidative stress index only in chronic hepatitis B subjects (p = 0.002, r = 0.519 and p = 0.008, r = 0.453, respectively. Conclusion Oxidative stress occurs secondarily to increased total lipid peroxidation and inadequate total antioxidant response and is related to severity of the disease and replication status of virus in hepatitis B infection.
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Mannarino, Matthew Marchand
Electrostatic fiber formation, or electrospinning, offers a particularly simple and robust method to create polymeric nanofibers of various sizes and morphologies. In electrospinning, a viscoelastic fluid is charged so that a liquid jet is ejected from the surface of the fluid (typically in the form of a drop supplied by a needle or spinneret) and collected on a grounded plate, creating a nonwoven fiber mat. Modification of the diameter of the fibers as well as the porosity, specific surface area, and mechanical properties of the mat allows one to tailor electrospun mats for specific applications. Despite the widespread and rapidly growing use of electrospinning in the fabrication of novel nanomaterials, there are no simple, universal methods of predicting, a priori, the properties of electrospun fibers from knowledge of the polymer solution properties and electrospinning operating conditions alone. Changing a single fluid or processing parameter can affect the jet and fiber formation through several mechanisms. For example, using a different solvent can change several properties of the electrospinning fluid, such as the dielectric constant, conductivity, surface tension, and solute-solvent interaction. The work in this thesis seeks to develop a simple relation for predicting terminal jet diameter during electrospinning, which accounts for solution viscoelasticity as well as solution conductivity and operating parameters that can be easily measured and controlled. The mechanical and tribological properties of electrospun fiber mats are of paramount importance to their utility as components in a variety of applications. Although some mechanical properties of these mats have been investigated previously, reports of their tribological properties are essentially nonexistent. In this thesis, electrospun nanofiber mats of poly(trimethyl hexamethylene terephthalamide) (PA 6(3)T) and poly(hexamethylene adipamide) (PA 6,6) are characterized mechanically and tribologically
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Bebout, Brad M.; Bucaria, Robin
2006-01-01
Microbial mats are living examples of the most ancient biological communities on Earth. As Earth's earliest ecosystems, they are centrally important to understanding the history of life on our planet and are useful models for the search for life elsewhere. As relatively compact (but complete) ecosystems, microbial mats are also extremely useful for educational activities. Mats may be used to demonstrate a wide variety of concepts in general and microbial ecology, including the biogeochemical cycling of elements, photosynthesis and respiration, and the origin of the Earth's present oxygen containing atmosphere. Microbial mats can be found in a number of common environments accessible to teachers, and laboratory microbial mats can be constructed using materials purchased from biological supply houses. With funding from NASA's Exobiology program, we have developed curriculum and web-based activities centered on the use of microbial mats as tools for demonstrating general principles in ecology, and the scientific process. Our web site (http://microbes.arc.nasa.gov) includes reference materials, lesson plans, and a "Web Lab", featuring living mats maintained in a mini-aquarium. The site also provides information as to how research on microbial mats supports NASA's goals, and various NASA missions. A photo gallery contains images of mats, microscopic views of the organisms that form them, and our own research activities. An animated educational video on the web site uses computer graphic and video microscopy to take students on a journey into a microbial mat. These activities are targeted to a middle school audience and are aligned with the National Science Standards.
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Microbial mat structures in profile: The Neoproterozoic Sonia Sandstone, Rajasthan, India
Samanta, Pradip; Mukhopadhyay, Soumik; Mondal, Anudeb; Sarkar, Subir
2011-01-01
Ubiquitous microorganisms, especially cyanobacteria preferably grow on the sediment surface thereby producing microbial mats. In the absence of grazers and bioturbators, microbial mat is a unique feature of the Proterozoic. Most of the papers so far published described a wide variety of bed surface microbial mat structures with rare illustrations from sections perpendicular to bedding. Nonetheless, bed surface exposures are relatively rare in rock records. This limitation of bed surface exposures in rock records suggest that a study of microbial mats in bed-across sections is needed. The 60 m thick coastal marine interval of the Sonia Sandstone Formation is bounded between two terrestrial intervals, a transgressive lag at the base and an unconformity at the top, and has been chosen for exploration of microbial mat structures in bed-across sections. A wide variety of microbial mat-induced structures in bed-across sections are preserved within the coastal interval of the Sonia Sandstone. Though many of these structures are similar in some aspects with bed surface structures, some of those presented here are new. The palaeogeographic range of these microbial structures extends from supralittoral to neritic. Diagenetic alterations of microbial mats produce pyrite and those zones are suitable for the preservation of microbial remains. SEM and EDAX analyses show fossil preservation of filamentous microbial remains that confirm the presence of microbial mats within the coastal interval of the Sonia Sandstone. Effects of proliferation of microbial mats in the siliciclastic depositional setting are numerous. The mat-cover on sediment surfaces hinders reworking and/or erosion of the sediments thereby increases the net sedimentation rate. Successive deposition and preservation of thick microbial mat layer under reducing environments should have a great potential for hydrocarbon production and preservation and therefore these Proterozoic formations could be a target for
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Two-step activation of meiosis by the mat1 locus in Schizosaccharomyces pombe
DEFF Research Database (Denmark)
Willer, M; Hoffmann, Ulla-Lisbeth; Styrkársdóttir, U
1995-01-01
of meiosis is based largely on indirect observations, and a more precise investigation of these events was required to define the interaction between the mat1 genes. Here we resolve this issue using synthetic pheromones and P/M strains with mutations in either mat1-Pc or mat1-Mc. Our results suggest a model...... in which the mat1 locus plays two roles in controlling meiosis. In the first instance, the mat1-Pc and mat1-Mc functions are required to produce the mating pheromones and receptors that allow the generation of a pheromone signal. This signal is required to induce the expression of mat1-Pm and mat1-Mm...
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Storage of yerba maté in controlled atmosphere
Directory of Open Access Journals (Sweden)
Sarah Lemos Cogo Prestes
2014-04-01
Full Text Available The aim of this study was to evaluate the effect of controlled atmosphere in the change of color, chlorophyll degradation and phenolic compounds concentration in yerba maté thickly ground (“cancheada” and thinly milled (“socada”. Yerba maté samples from the towns of Arvorezinha (RS - Brazil and São Mateus do Sul (PR - Brazil were stored in four levels of oxygen (1, 3, 6 and 20.9kPa of O2 and four levels of carbon dioxide (0, 3, 6 and 18kPa of CO2 and then were analyzed, after nine months of storage. According to the results, the O2 partial pressure reduction decreased the loss of green coloration, kept a higher content of chlorophylls and of total phenolic compounds. In relation to the different levels of CO2, a response as remarkable as O2 was not observed. The yerba maté that was thickly ground (“cancheada” presented a better storage potential than the one thinly milled (“socada” in the storage with O2 and with CO2. The 1kPa of O2 condition kept the yerba maté greener and with a higher content of chlorophylls and of total phenolic compounds after nine months of storage. The CO2 partial pressure kept the yerba maté coloration greener and with a higher content of chlorophylls and of total phenolic compounds, regardless of the level used, in the maté from both cultivation areas.
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Critique de la dématérialisation
Robert , Pascal
2004-01-01
International audience; La notion de " dématérialisation " constitue actuellement l'une des pièces maîtresses de l'idéologie de la communication. Or, après enquête, nous constatons que la dématérialisation ne se rencontre ni dans les TIC ni dans les réseaux où se dévoilent en revanche un nouveau mode de matérialisation ainsi qu'un processus de virtualisation par changement d'échelle. Nous nous interrogeons donc sur la fonction sociale et politique que cette notion joue dans les discours qui l...
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Fabrication of nanofiber mats from electrospinning of functionalized polymers
Oktay, Burcu; Kayaman-Apohan, Nilhan; Erdem-Kuruca, Serap
2014-08-01
Electrospinning technique enabled us to prepare nanofibers from synthetic and natural polymers. In this study, it was aimed to fabricate electrospun poly(vinyl alcohol) (PVA) based nanofibers by reactive electrospinning process. To improve endurance of fiber toward to many solvents, PVA was functionalized with photo-crosslinkable groups before spinning. Afterward PVA was crosslinked by UV radiation during electrospinning process. The nanofiber mats were characterized by scanning electron microscopy (SEM). The results showed that homogenous, uniform and crosslinked PVA nanofibers in diameters of about 200 nm were obtained. Thermal stability of the nanofiber mat was investigated with thermal gravimetric analysis (TGA). Also the potential use of this nanofiber mats for tissue engineering was examined. Osteosarcoma (Saos) cells were cultured on the nanofiber mats.
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Fabrication of nanofiber mats from electrospinning of functionalized polymers
International Nuclear Information System (INIS)
Oktay, Burcu; Kayaman-Apohan, Nilhan; Erdem-Kuruca, Serap
2014-01-01
Electrospinning technique enabled us to prepare nanofibers from synthetic and natural polymers. In this study, it was aimed to fabricate electrospun poly(vinyl alcohol) (PVA) based nanofibers by reactive electrospinning process. To improve endurance of fiber toward to many solvents, PVA was functionalized with photo-crosslinkable groups before spinning. Afterward PVA was crosslinked by UV radiation during electrospinning process. The nanofiber mats were characterized by scanning electron microscopy (SEM). The results showed that homogenous, uniform and crosslinked PVA nanofibers in diameters of about 200 nm were obtained. Thermal stability of the nanofiber mat was investigated with thermal gravimetric analysis (TGA). Also the potential use of this nanofiber mats for tissue engineering was examined. Osteosarcoma (Saos) cells were cultured on the nanofiber mats
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Matting Of Hair Due To ′Sunsilk′ Shampoo
Directory of Open Access Journals (Sweden)
Nadeem Mohd
1995-01-01
Full Text Available Matting of hair been reported from time to time due to treatment of hair with detergent, shampoos, waving lotions, setting lotions and bleaches. A case of matting of hairs in a young girl due to a change in the brand of shampoo is reported.
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Regulation of electron transfer processes affects phototrophic mat structure and activity
Ha, Phuc T.; Renslow, Ryan S.; Atci, Erhan; Reardon, Patrick N.; Lindemann, Stephen R.; Fredrickson, James K.; Call, Douglas R.; Beyenal, Haluk
2015-01-01
Phototrophic microbial mats are among the most diverse ecosystems in nature. These systems undergo daily cycles in redox potential caused by variations in light energy input and metabolic interactions among the microbial species. In this work, solid electrodes with controlled potentials were placed under mats to study the electron transfer processes between the electrode and the microbial mat. The phototrophic microbial mat was harvested from Hot Lake, a hypersaline, epsomitic lake located ne...
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Evaluation of polyacrylonitrile electrospun nano-fibrous mats as leukocyte removal filter media.
Pourbaghi, Raha; Zarrebini, Mohammad; Semnani, Dariush; Pourazar, Abbasali; Akbari, Nahid; Shamsfar, Reihaneh
2017-09-13
Removal of leukocytes from blood products is the most effective means for elimination of undesirable side effects and prevention of possible reactions in recipients. Micro-fibrous mats are currently used for removal of leukocytes from blood. In this study, samples of electrospun nano-fibrous mats were produced. The performance of the produced electrospun nano-fibrous mats as means of leukocytes removal from fresh whole blood was both evaluated and compared with that of commercially available micro-fibrous mats. In order to produce the samples, polyacrylonitrile (PAN) nano-fibrous mats were made under different electrospinning conditions. Mean fiber diameter, pore characterization and surface roughness of the PAN nano-fibrous mats were determined using image processing technique. In order to evaluate the surface tension of the fabricated mats, water contact angle was measured. The leukocyte removal performance, erythrocytes recovery percent and hemolysis rate of the nano-fibrous mats were compared. The effectiveness of nano-fibrous mats in removing leukocyte was established using both scanning electron microscope and optical microscope. Results showed that for given weight, the fabricated nano-fibrous mats were not only more efficient but also more cost-effective than their commercial counterparts. Results confirmed that changes in mean fiber diameter, the number of layer and weight of each layer in the absence of any chemical reaction or physical surface modification, the fabricated nano-fibrous mats were able to remove 5-log of leukocytes. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2017. © 2017 Wiley Periodicals, Inc.
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Zhang, Xiazhi; Guo, Rui; Xu, Jiqing; Lan, Yong; Jiao, Yanpeng; Zhou, Changren; Zhao, Yaowu
2015-11-01
In this study, poly(L-lactide) (PLLA)/halloysite nanotube (HNT) electrospun mats were prepared as a dual-drug delivery system. HNTs were used to encapsulate polymyxin B sulphate (a hydrophilic drug). Dexamethasone (a hydrophobic drug) was directly dissolved in the PLLA solution. The drug-loaded HNTs with optimised encapsulation efficiency were then mixed with the PLLA solution for subsequent electrospinning to form composite dual-drug-loaded fibre mats. The structure, morphology, degradability and mechanical properties of the electrospun composite mats were characterised in detail. The results showed that the HNTs were uniformly distributed in the composite PLLA mats. The HNTs content in the mats could change the morphology and average diameter of the electrospun fibres. The HNTs improved both the tensile strength of the PLLA electrospun mats and their degradation ratio. The drug-release kinetics of the electrospun mats were investigated using ultraviolet-visible spectrophotometry. The HNTs/PLLA ratio could be varied to adjust the release of polymyxin B sulphate and dexamethasone. The antibacterial activity in vitro of the mats was evaluated using agar diffusion and turbidimetry tests, which indicated the antibacterial efficacy of the dual-drug delivery system against Gram-positive and -negative bacteria. Healing in vivo of infected full-thickness burns and infected wounds was investigated by macroscopic observation, histological observation and immunohistochemical staining. The results indicated that the electrospun mats were capable of co-loading and co-delivering hydrophilic and hydrophobic drugs, and could potentially be used as novel antibacterial wound dressings. © The Author(s) 2015.
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MAT@USC Candidates and Latino English Language Learners
Lomeli, Cynthia Leticia
2012-01-01
The purpose of this study was to further understand the perceptions of MAT@USC teacher candidates and how their perceptions and previous experiences affect the educational experiences of Latino English language learners. Three questions were developed to guide this study: (1) What are the perceptions of MAT@USC candidates in selected courses…
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International Nuclear Information System (INIS)
Montrose, Kristopher; Krissansen, Geoffrey W.
2014-01-01
Highlights: • A novel proteolysis targeting chimeric molecule (PROTAC) to treat hepatitis B. • The PROTAC antagonizes and destroys the X-protein of the hepatitis B virus. • The PROTAC is a fusion of the X-protein oligomerization and instability domains. • The oligomerization domain is a dominant-negative inhibitor of X-protein function. • X-protein-targeting PROTACs have potential to prevent hepatocellular carcinoma. - Abstract: The X-protein of the hepatitis B virus (HBV) is essential for virus infection and contributes to the development of HBV-induced hepatocellular carcinoma (HCC), a disease which causes more than one million deaths each year. Here we describe the design of a novel PROTAC (proteolysis targeting chimeric molecule) capable of simultaneously inducing the degradation of the X-protein, and antagonizing its function. The PROTAC was constructed by fusing the N-terminal oligomerization and C-terminal instability domains of the X-protein to each other, and rendering them cell-permeable by the inclusion of a polyarginine cell-penetrating peptide (CPP). It was predicted that the oligomerization domain would bind the X-protein, and that the instability domain would cause the X-protein to be targeted for proteasomal degradation. Addition of the PROTAC to HepG2 liver cancer cells, engineered to express full-length and C-terminally truncated forms of the X-protein, resulted in the degradation of both forms of the X-protein. A cell-permeable stand-alone form of the oligomerization domain was taken up by HepG2 cells, and acted as a dominant-negative inhibitor, causing inhibition of X-protein-induced apoptosis. In summary, the PROTAC described here induces the degradation of the X-protein, and antagonizes its function, and warrants investigation in a preclinical study for its ability to prevent or treat HBV infection and/or the development of HCC
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Energy Technology Data Exchange (ETDEWEB)
Montrose, Kristopher; Krissansen, Geoffrey W., E-mail: gw.krissansen@auckland.ac.nz
2014-10-31
Highlights: • A novel proteolysis targeting chimeric molecule (PROTAC) to treat hepatitis B. • The PROTAC antagonizes and destroys the X-protein of the hepatitis B virus. • The PROTAC is a fusion of the X-protein oligomerization and instability domains. • The oligomerization domain is a dominant-negative inhibitor of X-protein function. • X-protein-targeting PROTACs have potential to prevent hepatocellular carcinoma. - Abstract: The X-protein of the hepatitis B virus (HBV) is essential for virus infection and contributes to the development of HBV-induced hepatocellular carcinoma (HCC), a disease which causes more than one million deaths each year. Here we describe the design of a novel PROTAC (proteolysis targeting chimeric molecule) capable of simultaneously inducing the degradation of the X-protein, and antagonizing its function. The PROTAC was constructed by fusing the N-terminal oligomerization and C-terminal instability domains of the X-protein to each other, and rendering them cell-permeable by the inclusion of a polyarginine cell-penetrating peptide (CPP). It was predicted that the oligomerization domain would bind the X-protein, and that the instability domain would cause the X-protein to be targeted for proteasomal degradation. Addition of the PROTAC to HepG2 liver cancer cells, engineered to express full-length and C-terminally truncated forms of the X-protein, resulted in the degradation of both forms of the X-protein. A cell-permeable stand-alone form of the oligomerization domain was taken up by HepG2 cells, and acted as a dominant-negative inhibitor, causing inhibition of X-protein-induced apoptosis. In summary, the PROTAC described here induces the degradation of the X-protein, and antagonizes its function, and warrants investigation in a preclinical study for its ability to prevent or treat HBV infection and/or the development of HCC.
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Poovitha, Sundar; Stalin, Nithaniyal; Balaji, Raju; Parani, Madasamy
2016-12-01
The genus Hibiscus L. includes several taxa of medicinal value and species used for the extraction of natural dyes. These applications require the use of authentic plant materials. DNA barcoding is a molecular method for species identification, which helps in reliable authentication by using one or more DNA barcode marker. In this study, we have collected 44 accessions, representing 16 species of Hibiscus, distributed in the southern peninsular India, to evaluate the discriminatory power of the two core barcodes rbcLa and matK together with the suggested additional regions trnH-psbA and ITS2. No intraspecies divergence was observed among the accessions studied. Interspecies divergence was 0%-9.6% with individual markers, which increased to 0%-12.5% and 0.8%-20.3% when using two- and three-marker combinations, respectively. Differentiation of all the species of Hibiscus was possible with the matK DNA barcode marker. Also, in two-marker combinations, only those combinations with matK differentiated all the species. Though all the three-marker combinations showed 100% species differentiation, species resolution was consistently better when the matK marker formed part of the combination. These results clearly showed that matK is more suitable when compared to rbcLa, trnH-psbA, and ITS2 for species identification in Hibiscus.
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Detection of hepatitis G virus-RNA (HGV-RNA) in serum of patients with HBV hepatitis
International Nuclear Information System (INIS)
Zhu Jingfei; Hang Shangrong; Chen Min; Pu Xiangke; Wang Yongzhong; Zhou Guoping
2007-01-01
Objective: To investigate the incidence of HGV infection in patients with HBV hepatitis and any possible adverse effect of the superinfection. Methods: Serum HGV-RNA expression was examined with PCR in 1104 patients with HBV hepatitis and 251 controls. Results: The positive rate of HGV-RNA in HBV hepatitis patients was not significantly different from that in controls (3.17% vs 2.79%, P>0.05). Among the patients with HBV hepatitis, HGV-RNA positive rate in patients with chronic hepatitis was significantly higher than that in patients with acute hepatitis (4.78% vs 0.96, P<0.05). Conclusion: HGV infection might be presented as non-symptomatic carriers or other mild form of hepatitis. The incidence of HGV infection was not especially high in HBV hepatitis patients, however, concomitant HGV and HBV infection might predispose to development of chronicity. (authors)
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Protein and Bacterial Antifouling Behavior of Melt-Coextruded Nanofiber Mats.
Kim, Si-Eun; Zhang, Cong; Advincula, Abigail A; Baer, Eric; Pokorski, Jonathan K
2016-04-13
Antifouling surfaces are important for biomedical devices to prevent secondary infections and mitigate the effects of the foreign body response. Herein, we describe melt-coextruded poly(ε-caprolactone) (PCL) nanofiber mats grafted with antifouling polymers. Nonwoven PCL fiber mats are produced using a multilayered melt coextrusion process followed by high-pressure hydroentanglement to yield porous patches. The resulting fiber mats show submicrometer cross-sectional fiber dimensions and yield pore sizes that were nearly uniform, with a mean pore size of 1.6 ± 0.9 μm. Several antifouling polymers, including hydrophilic, zwitterionic, and amphipathic molecules, are grafted to the surface of the mats using a two-step procedure that includes photochemistry followed by the copper-catalyzed azide-alkyne cycloaddition reaction. Fiber mats are evaluated using separate adsorption tests for serum proteins and E. coli. The results indicate that poly(oligo(ethylene glycol) methyl ether methacrylate)-co-(trifluoroethyl methacrylate) (poly(OEGMEMA-co-TFEMA)) grafted mats exhibit approximately 85% less protein adhesion and 97% less E. coli adsorption when compared to unmodified PCL fibermats. In dynamic antifouling testing, the amphiphilic fluorous polymer surface shows the highest flux and highest rejection value of foulants. The work presented within has implications on the high-throughput production of antifouling microporous patches for medical applications.
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Izumi, Kenichi; Unno, Chigusa
2010-04-01
The influence of the feeding ratio of a non-forage fiber source and hay on ruminal mat characteristics and chewing activity was evaluated in dairy dry cows. Cows were fed four different diets: the ratios of alfalfa hay (AH) to beet pulp (BP) were 8:2 (dry matter basis, A8B2) and 2:8 (A2B8), and those of grass hay (GH) to BP were 8:2 (G8B2) and 2:8 (G2B8). Total eating time was decreased with increasing BP content (P rumination time for AH was shorter than that for GH (P content (P ruminal mat was detected by using a penetration resistance test of the rumen digesta. Penetration resistance value (PRV) of ruminal mat was highest with the G8B2 diet and PRV decreased with increasing BP content (P ruminal mat was greater for increasing BP content (P ruminal mat PRV on total rumination time resulted in a high positive correlation (r = 0.744; P ruminal mat stimulated rumination activity and a ruminal mat could be formed, although it was soft even when cows were offered a large quantity of BP.
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Flow of light energy in benthic photosynthetic microbial mats
Energy Technology Data Exchange (ETDEWEB)
Al-Najjar, Mohammad Ahmad A.
2010-12-15
The work in this thesis demonstrates the assessment of the energy budget inside microbial mat ecosystems, and the factors affecting light utilization efficiency. It presents the first balanced light energy budget for benthic microbial mat ecosystems, and shows how the budget and the spatial distribution of the local photosynthetic efficiencies within the euphotic zone depend on the absorbed irradiance (Jabs). The energy budget was dominated by heat dissipation on the expense of photosynthesis. The maximum efficiency of photosynthesis was at light limiting conditions When comparing three different marine benthic photosynthetic ecosystems (originated from Abu-Dhabi, Arctic, and Exmouth Gulf in Western Australia), differences in the efficiencies were calculated. The results demonstrated that the maximum efficiency depended on mat characteristics affecting light absorption and scattering; such as, photopigments ratio and distribution, and the structural organization of the photosynthetic organisms relative to other absorbing components of the ecosystem (i.e., EPS, mineral particles, detritus, etc.). The maximum efficiency decreased with increasing light penetration depth, and increased with increasing the accessory pigments (phycocyanin and fucoxanthin)/chlorophyll ratio. Spatial heterogeneity in photosynthetic efficiency, pigment distribution, as well as light acclimation in microbial mats originating from different geographical locations was investigated. We used a combined pigment imaging approach (variable chlorophyll fluorescence and hyperspectral imaging), and fingerprinting approach. For each mat, the photosynthetic activity was proportional to the local pigment concentration in the photic zone, but not for the deeper layers and between different mats. In each mat, yield of PSII and E1/2 (light acclimation) generally decreased in parallel with depth, but the gradients in both parameters varied greatly between samples. This mismatch between pigments concentration
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Enhancing the mechanical properties of electrospun polyester mats by heat treatment
Directory of Open Access Journals (Sweden)
M. Kancheva
2015-01-01
Full Text Available Microfibrous materials with a targeted design based on poly(L-lactic acid (PLA and poly(ε-caprolactone (PCL were prepared by electrospinning and by combining electrospinning and electrospraying. Several approaches were used: (i electrospinning of a common solution of the two polymers, (ii simultaneous electrospinning of two separate solutions of PLA and PCL, (iii electrospinning of PLA solution in conjunction with electrospraying of PCL solution, and (iv alternating layer-by-layer deposition by electrospinning of separate PLA and PCL solutions. The mats were heated at the melting temperature of PCL (60°", thus achieving melting of PCL fibers/particles and thermal sealing of the fibers. The mats subjected to thermal treatment were characterized by greater mean fiber diameters and reduced values of the water contact angle compared to the pristine mats. Heat treatment of the mats affected their thermal stability and led to an increase in the crystallinity degree of PLA incorporated in the mats, whereas that of PCL was reduced. All mats were characterized by enhanced mechanical properties after thermal treatment as compared to the non-treated fibrous materials.
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Directory of Open Access Journals (Sweden)
Katrina A. Rieger
2016-04-01
Full Text Available Quantifying the effect that nanofiber mat chemistry and hydrophilicity have on microorganism collection and inactivation is critical in biomedical applications. In this study, the collection and inactivation of Escherichia coli K12 was examined using cellulose nanofiber mats that were surface-functionalized using three polyelectrolytes: poly (acrylic acid (PAA, chitosan (CS, and polydiallyldimethylammonium chloride (pDADMAC. The polyelectrolyte functionalized nanofiber mats retained the cylindrical morphology and average fiber diameter (~0.84 µm of the underlying cellulose nanofibers. X-ray photoelectron spectroscopy (XPS and contact angle measurements confirmed the presence of polycations or polyanions on the surface of the nanofiber mats. Both the control cellulose and pDADMAC-functionalized nanofiber mats exhibited a high collection of E. coli K12, which suggests that mat hydrophilicity may play a larger role than surface charge on cell collection. While the minimum concentration of polycations needed to inhibit E. coli K12 was 800 µg/mL for both CS and pDADMAC, once immobilized, pDADMAC-functionalized nanofiber mats exhibited a higher inactivation of E. coli K12, (~97%. Here, we demonstrate that the collection and inactivation of microorganisms by electrospun cellulose nanofiber mats can be tailored through a facile polyelectrolyte functionalization process.
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Rieger, Katrina A.; Porter, Michael; Schiffman, Jessica D.
2016-01-01
Quantifying the effect that nanofiber mat chemistry and hydrophilicity have on microorganism collection and inactivation is critical in biomedical applications. In this study, the collection and inactivation of Escherichia coli K12 was examined using cellulose nanofiber mats that were surface-functionalized using three polyelectrolytes: poly (acrylic acid) (PAA), chitosan (CS), and polydiallyldimethylammonium chloride (pDADMAC). The polyelectrolyte functionalized nanofiber mats retained the cylindrical morphology and average fiber diameter (~0.84 µm) of the underlying cellulose nanofibers. X-ray photoelectron spectroscopy (XPS) and contact angle measurements confirmed the presence of polycations or polyanions on the surface of the nanofiber mats. Both the control cellulose and pDADMAC-functionalized nanofiber mats exhibited a high collection of E. coli K12, which suggests that mat hydrophilicity may play a larger role than surface charge on cell collection. While the minimum concentration of polycations needed to inhibit E. coli K12 was 800 µg/mL for both CS and pDADMAC, once immobilized, pDADMAC-functionalized nanofiber mats exhibited a higher inactivation of E. coli K12, (~97%). Here, we demonstrate that the collection and inactivation of microorganisms by electrospun cellulose nanofiber mats can be tailored through a facile polyelectrolyte functionalization process. PMID:28773422
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Phylogenetic stratigraphy in the Guerrero Negro hypersaline microbial mat.
Harris, J Kirk; Caporaso, J Gregory; Walker, Jeffrey J; Spear, John R; Gold, Nicholas J; Robertson, Charles E; Hugenholtz, Philip; Goodrich, Julia; McDonald, Daniel; Knights, Dan; Marshall, Paul; Tufo, Henry; Knight, Rob; Pace, Norman R
2013-01-01
The microbial mats of Guerrero Negro (GN), Baja California Sur, Mexico historically were considered a simple environment, dominated by cyanobacteria and sulfate-reducing bacteria. Culture-independent rRNA community profiling instead revealed these microbial mats as among the most phylogenetically diverse environments known. A preliminary molecular survey of the GN mat based on only ∼1500 small subunit rRNA gene sequences discovered several new phylum-level groups in the bacterial phylogenetic domain and many previously undetected lower-level taxa. We determined an additional ∼119,000 nearly full-length sequences and 28,000 >200 nucleotide 454 reads from a 10-layer depth profile of the GN mat. With this unprecedented coverage of long sequences from one environment, we confirm the mat is phylogenetically stratified, presumably corresponding to light and geochemical gradients throughout the depth of the mat. Previous shotgun metagenomic data from the same depth profile show the same stratified pattern and suggest that metagenome properties may be predictable from rRNA gene sequences. We verify previously identified novel lineages and identify new phylogenetic diversity at lower taxonomic levels, for example, thousands of operational taxonomic units at the family-genus levels differ considerably from known sequences. The new sequences populate parts of the bacterial phylogenetic tree that previously were poorly described, but indicate that any comprehensive survey of GN diversity has only begun. Finally, we show that taxonomic conclusions are generally congruent between Sanger and 454 sequencing technologies, with the taxonomic resolution achieved dependent on the abundance of reference sequences in the relevant region of the rRNA tree of life.
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Directory of Open Access Journals (Sweden)
Haider Fyeza S
2008-08-01
Full Text Available Abstract Introduction Primary hepatic lymphoma is an unusual form of non-Hodgkin's lymphoma that usually presents with constitutional symptoms, hepatomegaly and signs of cholestatic jaundice. Diffuse hepatic infiltration is uncommon and presentation with acute hepatic failure even more rare. The presence of markedly elevated ferritin levels can complicate the evaluation process and suggest alternative diagnoses. We present the case of a middle-aged woman exhibiting pancytopenia, hyperferritinemia and rapidly deteriorating to develop acute hepatic failure. Her initial clinical picture led to a working diagnosis of adult onset Still's disease with probable hemophagocytic syndrome before her worsening liver function necessitated a percutaneous liver biopsy and establishment of the final diagnosis of primary hepatic lymphoma. Conclusion Primary hepatic lymphoma is an uncommon malignancy and its manifestation as progressive hepatitis or acute fulminant hepatic failure can be difficult to diagnose. The presence of constitutional symptoms, pancytopenia and high ferritin levels can complicate the evaluation process. A liver biopsy early in the course of liver dysfunction may establish the diagnosis without a higher risk of bleeding complications seen once liver failure sets in.
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Synthesis of CuAlO2 nanofibrous mats by electrospinning
International Nuclear Information System (INIS)
Zhao Shizhen; Li Miaoyu; Liu Xiaomin; Han Gaoyi
2009-01-01
Electrospinning as a versatile method for preparation of nanofibers has been used to fabricate the polyvinylalcohol nanofibers containing equal molar of aluminum nitrate and copper acetate. After pretreated at 400 deg. C, the composite fibrous mats were annealed at 1100 deg. C in air for 5 h and then the delafossite-structured p-type CuAlO 2 ceramics fibrous mats were obtained. The obtained CuAlO 2 ceramics fibrous mats were characterized by scanning electrical microscope, X-ray diffraction and diffuse reflectance spectroscopy. The direct energy gap of the prepared CuAlO 2 ceramics fibrous mats was measured to be about 3.38 eV. The CuAlO 2 behaved like semiconductors and the thermally activated energy was about 0.25 eV.
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Asthenia in Children with Chronic Viral Hepatitis
Directory of Open Access Journals (Sweden)
I.S. Lembryk
2015-02-01
Full Text Available In the article results of own researches concerning peculiarities of the course of asthenic syndrome in school-aged children with chronic hepatitis B, C and mixed forms are provided. It is established that chronic hepatitis C as well as a mixed hepatitis are accompanied by more evident symptoms of deadaptation and somatogenic asthenia than hepatitis B in which psychogenic manifestations prevailed. The degree of endogenous intoxication was also higher at hepatitis C.
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International Nuclear Information System (INIS)
Xiao Shili; Shi Xiangyang; Wu Siqi; Shen Mingwu; Guo Rui; Wang Shanyuan
2009-01-01
A facile approach that combines the electrospinning technique and layer-by-layer (LbL) assembly method has been developed to synthesize and immobilize zero-valent iron nanoparticles (ZVI NPs) onto the surface of nanofibers for potential environmental applications. In this approach, negatively charged cellulose acetate (CA) nanofibers fabricated by electrospinning CA solution were modified with bilayers composed of positively charged poly(diallyl-dimethyl-ammoniumchloride) (PDADMAC) and negatively charged poly(acrylic acid) (PAA) through electrostatic LbL assembly approach to form composite nanofibrous mats. The composite nanofibrous mats were immersed into the ferrous iron solution to allow Fe(II) ions to complex with the free carboxyl groups of PAA, and then ZVI NPs were immobilized onto the composite nanofibrous mats instantly by reducing the ferrous cations. Combined scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and thermogravimetry analysis demonstrated that the ZVI NPs are successfully synthesized and uniformly distributed into the polyelectrolyte (PE) multilayer films assembled onto the CA nanofibers. The present approach to synthesis ZVI NPs opens a new avenue to fabricating various materials with high surface area for environmental, catalytic, and sensing applications.
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LONG-TERM CONSEQUENCES OF HEPATITIS A IN CHILDREN
Directory of Open Access Journals (Sweden)
V. F. Uchaikin
2014-01-01
Full Text Available Various embodiments of lingering forms of hepatitis A, for the aggravation still cause differential diagnostic difficulties and mistakes. Continuing to the present heavy and cholestasis form of hepatitis A in children, fulminant form of adolescents, adults and pregnant women let to suggest this issue to be relevance. The task of vaccine prevention of hepatitis A in the National Immunization ScheduleRussiakeeping up to be relevance and perspective. Numerous studies have shown that the French vaccine AVAXIM 80 showed good immunogenicity and safety vaccinate in children.
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Flakeboard thickness swelling. Part I, Stress relaxation in a flakeboard mat
R. L. Geimer; J. H. Kwon; J. Bolton
1998-01-01
The steam injection schedule best suited for dimensionally stabilizing a flake mat is one in which steam treatment is initiated before the press is closed and is continued at least until the mat attains target thickness. Experiments showed that resinless mats treated with 20 sec of steam at 600 kPa had maximum thickness swelling of 205% compared to 350% for resinless...
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Location and associated carbon storage of erosional escarpments of seagrass Posidonia mats
Directory of Open Access Journals (Sweden)
Oscar eSerrano
2016-03-01
Full Text Available Seagrasses of the genus Posidonia can form an irregular seascape due to erosional processes exposing thick walls of organic matter-rich soils. However, little is known about the location and characteristics of these particular formations. Here we provide comprehensive estimates of organic carbon (Corg storage in P. oceanica and P. australis meadows, while providing insight into their location and mechanisms of formation, and highlighting future research directions. Erosional reef escarpments are restricted to shallow highly productive P. oceanica meadows from the Mediterranean Sea and P. australis meadows from the Indian Ocean, and sustain the existence of Corg-rich deposits in surrounding meadows. The thickness of the mat escarpments can reach up to 3 m and their length can vary from few to hundreds meters. Mechanisms of formation appear to differ among sites, from naturally-induced escarpments by wave action and/or tidal flow to human-induced escarpments by dredging activities. The inter-twined remains of seagrass shoots within the sediment matrix consolidate the sandy substrate and hold the exposed Posidonia mat escarpments together, maintaining a semi-rigid structure. This phenomenon is unusual but of exceptional importance in marine biogeochemical cycles, revealing the largest Corg sinks among seagrasses worldwide (ranging from 15-176 kg Corg m-2 in 2 m-thick mats accumulated at 2-249 g Corg m-2 yr-1 over 300 to 3000 yr.
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Sequester of metals and mineralization of organic contaminants with microbial mats
International Nuclear Information System (INIS)
Bender, J.; Phillips, P.; Gould, J.P.
1995-01-01
Several recalcitrant organic contaminants are completely mineralized to simple products by microbial mats. Contaminants include chlordane, PCB, TNT, petroleum distillates, BM compounds and TCE in a mixed contaminant solution containing Zn. Degradation rates are relatively rapid under both dark and light conditions. In addition to complete degradation of organic materials, mats have been used to reduce selenate to elemental selenium, remove Pb, Cd, Cu, Zn, Co, Cr, Fe and Mn from water and sequester uranium (U 238 ) at a rate of 3.19 mg/m 2 /h. Results of three pilot projects, including field pond treatment of mine drainage and bioreactor treatment of BTEX compounds will be reported. Microbial mats are natural heterotrophic and autotrophic communities dominated by cyanobacteria (blue-green algae). They are self-organized laminated structures annealed fightly together by slimy secretions from various microbial components. The surface slime of the mats effectively immobilizes the ecosystem to a variety of substrates, thereby stabilizing the most efficient internal microbial structure. Cyanobacteria mats are generated for bioremediation applications by enriching a water surface with ensiled grass clippings together with mat inocula developed in the laboratory
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Matsuda, Chikashi; Moriyama, Hidehiko; Taketani, Takeshi; Shibata, Hiroshi; Nagai, Atsushi
2011-01-01
The presence in serum of the Hepatitis B surface antigen (HBsAg), the outer envelope of the hepatitis B virus (HBV), indicates viral infection, used in laboratory tests to confirm this. We report a case of discrepancy among HBsAg test results detected between measurements in a subject with HB infection. Gene analysis demonstrated several S region gene mutations, not detected previously. We tested 12 measurements e.g., EIA, CLIA, CLEIA, F-EIA, MAT, and IC for whether they could detect our subject's HBsAg and found that it was not recognized by a method using only a single monoclonal antibody to detect HBsAg in two detection processes, in contrast to the 11 other measurements, which used two different antibodies. This case shows that amino acid substitution may cause a false negative result for HBsAg. Gene mutations known to occur in HBV, should thus trigger an awareness of the need to keep in mind that false negative results can happen in case such as ours.
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Sugarbaker, Paul H
2018-07-01
The hepatic bridge forms a tunnel of liver parenchyma that may obscure peritoneal metastases associated with the round ligament. Visualization and then resection of nodules associated with this structure is necessary. The incidence of a hepatic bridge and the extent that it covered the round ligament was determined in consecutive patients. Extent of coverage of the round ligament by the hepatic bridge was determined: Class 1 indicates up to one-third of the round ligament obscured, Class 2 up to two-thirds and Class 3 more than two-thirds. In 102 patients in whom the round ligament of the liver could be completely visualized, 50 had a hepatic bridge. Class 1 was 22 (44%) of the bridges, Class 2 was 16 (32%) and Class 3 was 12 (24%). A hepatic bridge was more frequently present in 28 of 45 male patients (62%) vs. 22 of 57 female patients (38%). Approximately one-half of our patients having cytoreductive surgery for peritoneal metastases were observed to have a hepatic bridge. Up to 56% of these patients have Class 2 or 3 hepatic bridge and may require division of the hepatic bridge to completely visualize the contents of the tunnel created by this structure. Copyright © 2018 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.
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Pusporini, Pusporini; Edikresnha, Dhewa; Sriyanti, Ida; Suciati, Tri; Miftahul Munir, Muhammad; Khairurrijal, Khairurrijal
2018-05-01
Electrospinning was employed to make PVP (polyvinylpyrrolidone)/GTE (green tea extract) composite nanofiber mats. The electrospun PVP nanofiber mat as well as the PVP/GTE nanofiber mats were uniform. The average fiber diameter of PVP/GTE composite nanofiber mat decreased with increasing the GTE weight fraction (or decreasing the PVP weight fraction) in the PVP/GTE solution because the PVP/GTE solution concentration decreased. Then, the broad FTIR peak representing the stretching vibrations of O–H in hydroxyl groups of phenols and the stretching of N–H in amine groups of the GTE paste shifted to higher wavenumbers in the PVP/GTE composite nanofiber mats. These peak shifts implied that PVP and catechins of GTE in the PVP/GTE composite nanofiber mats had intermolecular interactions via hydrogen bonds between carbonyl groups of PVP and hydroxyl groups of catechins in GTE. Lastly, the antioxidant activity of the PVP/GTE composite nanofiber mat increased with reducing the average fiber diameter because the amount of catechins in the composite nanofiber mat increased with the increase of surface area due to the reduction of the average fiber diameter.
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MICROBIAL MATS - A JOINT VENTURE
VANGEMERDEN, H
Microbial mats characteristically are dominated by a few functional groups of microbes: cyanobacteria, colorless sulfur bacteria, purple sulfur bacteria, and sulfate-reducing bacteria. Their combined metabolic activities result in steep environmental microgradients, particularly of oxygen and
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Photosynthetic microbial mats today, on early Earth, (and on early Mars?)
Des Marais, D. J.
2008-05-01
Marine hypersaline cyanobacterial mats offer insights about their ancient ancestors, whose fossil record is 3.43 billion years old. Studies of mat microbiota have greatly expanded the known diversity of ancient microbial lineages. Their evolution was shaped by mat microenvironments, which can differ substantially from their surroundings. Oxygenic photosynthesis perhaps developed in microbial mats and probably triggered a major evolutionary transformation and diversification of the early biosphere. Gross primary production rates in cyanobacterial mats can rival the most productive ecosystems known. Sunlight changes in intensity and spectral composition as it penetrates mats, and counteracting gradients of O2 and sulfide shape the chemical microenvironment. A combination of benefits and hazards of light, O2 and sulfide promotes the allocation of the various essential mat processes between light and dark periods and to various depths in the mat. Close inspection has revealed surprises, for example: anoxygenic phototrophs inside cyanobacterial sheaths, record- high sulfate reduction rates in O2-saturated conditions, and high H2 fluxes into overlying waters. Diverse organic biomarker compounds have been documented that are amenable to long-term preservation. Such coordinated observations of populations, processes and products are making fundamental questions in ecology accessible. Cyanobacterial mats have robust fossil records in part because they populated stable continental platforms and margins, contributing to sediments having high preservation potential. Proterozoic cyanobacterial fossils and organic biomarkers are well documented. The 3.43 Ga Strelley Pool cherts, W. Australia, reveal diverse stromatolites that populated a partially restricted, low-energy shallow hypersaline basin. Molecular studies of extant bacteria hint that early chlorophyll-utilizing photosynthesizers required geochemical sources of reductants. Did these anoxygenic phototrophs once sustain an
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Kohsari, Iraj; Shariatinia, Zahra; Pourmortazavi, Seied Mahdi
2016-10-01
Antimicrobial chitosan-polyethylene oxide (CS-PEO) nanofiber mats loaded with 3, 5 and 10% (w/w) of zeolitic imidazolate framework-8 nanoparticles (ZIF-8 NPs, ∼60nm diameter) were developed by electrospinning technique. The CS-PEO-GA-3% ZIF-8 NPs crosslinked with glutaraldehyde (GA) vapor was also prepared. The electrospun mats were characterized by various analysis including FE-SEM, EDAX, elemental mapping, FT-IR, contact angle, TGA/DSC as well as tensile strength analysis. The nanofibers had average diameters within the range ∼70-120nm. Antimicrobial activities of the CS-PEO and CS-PEO-3% ZIF-8 mats were evaluated by the viable cell-counting method for determining their effectiveness in reducing or halting the growth of Staphylococcus aureus and Escherichia coli bacteria so that the CS-PEO mat containing 3% ZIF-8 revealed 100% bactericidal activity against both kinds of bacteria. The crosslinked CS-PEO-GA-3% ZIF-8 NPs sample was less thermally stable but more hydrophilic than its related non-crosslinked mat reflecting there was no need to crosslink the fibers using a chemical crosslinker having adverse effects. The highest hydrophobicity and appropriate thermal and tensile properties of CS-PEO-3% ZIF-8 NPs among those of the mats including 5 and 10% ZIF-8 NPs suggested that the mentioned mat is the most suitable sample for food coating applications. Copyright © 2016 Elsevier B.V. All rights reserved.
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Carbon cycling and calcification in hypersaline microbial mats
Ludwig, Rebecca
2004-01-01
Phototrophic microbial mats are laminated aggregations of microorganisms that thrive in extreme and oligotrophic environments. Primary production rates by oxygenic phototrophs are extremely high. Primary producers supply heterotrophic mat members with organic carbon, which in turn regenerate CO2 needed for autotrophic carbon fixation. Another potential source of CO2 is calcification, which is known to shift the carbonate equilibrium towards CO2. This thesis investigated the carbon cycle of mi...
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Thermodynamics and phase transformations the selected works of Mats Hillert
Lilensten, Jean
2006-01-01
This book is a compendium of Mat Hillert's publications. Mat Hillert is a world specialist in metal alloy at the origin of a universal computing code used to calculate the diagrams of phase. This work is in English.
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Thermomechanical analyses of phenolic foam reinforced with glass fiber mat
International Nuclear Information System (INIS)
Zhou, Jintang; Yao, Zhengjun; Chen, Yongxin; Wei, Dongbo; Wu, Yibing
2013-01-01
Highlights: • Over 10% glass fiber was used to reinforce phenolic foam in the shape of glass fiber mat. • Nucleating agents were used together with glass fiber mat and improved tensile strength of phenolic foam by 215.6%. • Nucleating agents lead to a smaller bubble size of phenolic foam. • The glass transition temperature of phenolic foam remained unchanged during the reinforcement. - Abstract: In this paper, thermomechanical analysis (TMA) and dynamic mechanical analysis were employed to study the properties of phenolic foam reinforced with glass fiber mat. Unreinforced phenolic foam was taken as the control sample. Mechanical tests and scanning electron microscopy were performed to confirm the results of TMA. The results show that glass fiber mat reinforcement improves the mechanical performance of phenolic foam, and nucleating agents improve it further. Phenolic foam reinforced with glass fiber mat has a smaller thermal expansion coefficient compared with unreinforced foam. The storage modulus of the reinforced phenolic foam is also higher than that in unreinforced foam, whereas the loss modulus of the former is lower than that of the latter. The glass transition temperature of the phenolic foam matrix remains unchanged during the reinforcement
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Matei, Marius Febi; Jaiswal, Rakesh; Patras, Maria A; Kuhnert, Nikolai
2016-12-01
Yerba maté is one of the most popular beverages in South American countries and its consumption is associated with a wide array of health effects. In this study, we used advanced HPLC-ESI-MS n and HPLC-ESI-HRMS methods for the identification and characterization of hydroxycinnamates and their derivatives formed during the brewing process of yerba maté. We report on the hydroxylation of the hydroxycinnamates cinnamoyl substituent by conjugate addition of water to form 3-hydroxy-dihydrocinnamic acid derivatives using a series of model compounds, including caffeoylglucoses, dicaffeoylquinic acids, methyl caffeoylquinate and mono caffeoylquinic acids. The regiochemistry of conjugate addition was determined by targeted tandem MS experiments performed on authentic standards. It was interesting to note that hydroxylation of hydroxycinnamates produced cis and acyl-migration isomers, which is in line with previously reported data. Copyright © 2016. Published by Elsevier Ltd.
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... hepatitis is the most common form in North America. Type 1 can occur at any age; however, ... eastern time, M-F Follow Us NIH… Turning Discovery Into Health ® Research & Funding Current Funding Opportunities Research ...
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Exascale Co-Design Center for Materials in Extreme Environments (ExMatEx) Annual Report - Year 2
Energy Technology Data Exchange (ETDEWEB)
Germann, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Richards, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); McPherson, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Belak, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2013-11-25
All activities of the Exascale Co-design Center for Materials in Extreme Environments (Ex- MatEx) are focused on the two ultimate goals of the project: (1) demonstrating and delivering a prototype scale-bridging materials science application based upon adaptive physics refinement, and (2) identifying the requirements for the exascale ecosystem that are necessary to perform computational materials science simulations (both single- and multi-scale). During the first year of ExMatEx, our focus was on establishing how we do computational materials science, by developing an initial suite of flexible proxy applications. These “proxy apps” are the primary vehicle for the co-design process, involving assessments and tradeoff evaluations both within the ExMatEx team, and with the entire exascale ecosystem. These interactions have formed the basis of our second year activities. The set of artifacts from these co-design interactions are the lessons learned, that are used to re-express the applications and algorithms within the context of emerging architectures, programming models, and runtime systems.
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Validity Study of a Jump Mat Compared to the Reference Standard Force Plate.
Rogan, Slavko; Radlinger, Lorenz; Imhasly, Caroline; Kneubuehler, Andrea; Hilfiker, Roger
2015-12-01
In the field of vertical jump diagnostics, force plates (FP) are the reference standard. Recently, despite a lack of evidence, jump mats have been used increasingly. Important factors in favor of jumping mats are their low cost and portability. This validity study compared the Haynl-Elektronik jump mat (HE jump mat) with the reference standard force plate. Ten healthy volunteers participated and each participant completed three series of five drop jumps (DJ). The parameters ground contact time (GCT) and vertical jump height (VJH) from the HE jump mat and the FP were used to evaluate the concurrent validity. The following statistical calculations were performed: Pearson's correlation (r), Bland-Altman plots (standard and for adjusted trend), and regression equations. The Bland-Altman plots suggest that the HE jump mat measures shorter contact times and higher jump heights than the FP. The trend-adjusted Bland-Altman plot shows higher mean differences and wider wing-spreads of confidence limits during longer GCT. During the VJH the mean differences and the wing-spreads of the confidence limits throughout the range present as relatively constant. The following regression equations were created, as close as possible to the true value: GCT = 5.920385 + 1.072293 × [value HE jump mat] and VJH = -1.73777 + 1.011156 × [value HE jump mat]. The HE jump mat can be recommended in relation to the validity of constraints. In this study, only a part of the quality criteria were examined. For the final recommendation it is advised to examine the HE jump mat on the other quality criteria (test-retest reliability, sensitivity change).
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Volatile organic chemicals of a shore-dwelling cyanobacterial mat community.
Evans, W G
1994-02-01
The main components of a cyanobacterial mat community of a hypersaline lake shore consist of edaphic, mat-forming strains (ecophenes), and littoral strains ofOscillatoria animalis Agardh andO. subbrevis Schmidle, other microorganisms associated with these cyanobacteria, several species ofBembidion (Carabidae: Coleoptera), and two halophytic flowering plants:Puccinellia nuttalliana (salt meadow grass) andSalicornia europaea rubra (samphire). The volatile organic compounds of this community are a blend of those emitted by each of these components such as the C17 alka(e)nes, geosmin, 2-methylisoborneol,β-cyclocitral,β-ionone, dimethyl sulfide, and dimethyl trisulfide of cyanobacteria and associated microorganisms; alcohols, esters, and aldehydes usually associated with flowering plants; and possibly some insect-derived esters, particularly isopropyl tetradecanoate. The dominant compounds were: C11, C13, C15, and C17 alka(e)nes, methyl esters of C16 and C18:2 acids, isopropyl tetradecanoate, heptanal, 3-octanone and 2-nonanone, the acyclic terpene linalool, and the alcohols 1-heptanol, 1-hexanol, 1-octanol, 3-hexen-1-ol, and 2-octen-1-ol. It is concluded that this community may be distinguished from related communities by its repertoire of volatile organic compounds.
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Low-Light Anoxygenic Photosynthesis and Fe-S-Biogeochemistry in a Microbial Mat.
Haas, Sebastian; de Beer, Dirk; Klatt, Judith M; Fink, Artur; Rench, Rebecca McCauley; Hamilton, Trinity L; Meyer, Volker; Kakuk, Brian; Macalady, Jennifer L
2018-01-01
We report extremely low-light-adapted anoxygenic photosynthesis in a thick microbial mat in Magical Blue Hole, Abaco Island, The Bahamas. Sulfur cycling was reduced by iron oxides and organic carbon limitation. The mat grows below the halocline/oxycline at 30 m depth on the walls of the flooded sinkhole. In situ irradiance at the mat surface on a sunny December day was between 0.021 and 0.084 μmol photons m -2 s -1 , and UV light (97% sequence identity) of clones affiliated with Prosthecochloris , a genus within the green sulfur bacteria (GSB), which are obligate anoxygenic phototrophs. Typical photopigments of brown-colored GSB, bacteriochlorophyll e and (β-)isorenieratene, were abundant in mat samples and their absorption properties are well-adapted to harvest light in the available green and possibly even UV-A spectra. Sulfide from the water column (3-6 μmol L -1 ) was the main source of sulfide to the mat as sulfate reduction rates in the mats were very low (undetectable-99.2 nmol cm -3 d -1 ). The anoxic water column was oligotrophic and low in dissolved organic carbon (175-228 μmol L -1 ). High concentrations of pyrite (FeS 2 ; 1-47 μmol cm -3 ) together with low microbial process rates (sulfate reduction, CO 2 fixation) indicate that the mats function as net sulfide sinks mainly by abiotic processes. We suggest that abundant Fe(III) (4.3-22.2 μmol cm -3 ) is the major source of oxidizing power in the mat, and that abiotic Fe-S-reactions play the main role in pyrite formation. Limitation of sulfate reduction by low organic carbon availability along with the presence of abundant sulfide-scavenging iron oxides considerably slowed down sulfur cycling in these mats.
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Present, T. M.; Trower, L.; Stein, N.; Alleon, J.; Bahniuk, A.; Gomes, M. L.; Lingappa, U.; Metcalfe, K.; Orzechowski, E. A.; Riedman, L. A.; Sanders, C. B.; Morris, D. K.; O'Reilly, S.; Sibert, E. C.; Thorpe, M.; Tarika, M.; Fischer, W. W.; Knoll, A. H.; Grotzinger, J. P.
2017-12-01
Little Ambergris Cay (21.3° N, 71.7° W) was the site of an integrated geobiological study conducted in July 2016 and August 2017. The cay ( 6 km x 1.6 km) is developed on a broad bank influenced by strong easterly trade winds (avg. 7.5 m/s), where convergent ooid shoals culminate in a linear shoal extending almost 25 km westward from the cay. Lithified upper shoreface to eolian ooid grainstones form a 2 m high bedrock rim that protects an extensive interior tidal marsh with well-developed microbial mats. Local breaches in the rim allow tidal flows to inundate interior bays floored by microbial mats. Three mat types were observed based on texture: dark toned "blister mat" that flanks the bays where they intersect with the bedrock rim; light-toned "polygonal mat" that covers broad tracts of the bay and is exposed at low tide; and lighter-toned "EPS mat" that is generally submerged even at low tide. The millimeter-to decimeter-thick layered mats overlie laterally extensive ooid sands, generally unlithified except for a few hardgrounds. The mats and underlying sediments were sampled by vibracoring, push coring, and piezometers. Biogeochemical analyses include groundwater salinity, pH, DIC, alkalinity, cation composition, DNA content, photosynthetic efficiency, C and S isotope composition, lipid biomarkers, and taphonomic state. Groundwater and interstitial water chemical analyses were integrated with hydrologic observations of tidal channels' level and flow. Visible light UAV images from 350 m standoff distance were processed to generate a 15 cm/pixel mosaic of the island that was used in combination with a DGPS survey, multispectral Landsat images (m-scale resolution) and Worldview satellite images (30 cm resolution) to map the island's topography, mats, and sedimentologic facies. A UAV-based VNIR hyperspectral camera was used to quantify pigment concentrations in the mats at cm-resolution over decameter scales. Sub-cm-scale bed textures, including those expressed
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UV B-induced vertical migrations of cyanobacteria in a microbial mat
International Nuclear Information System (INIS)
Rebout, B.M.; Garcia-Pichel, F.
1995-01-01
Exposure to moderate doses of UV B (0.35 to 0.79 W m -2 s -1 or 0.98 to 2.2 μmol of photons m -2 s -1 at 310 nm) caused the surface layers of microbial mats from Solar Lake, Sinai, Egypt, to become visibly lighter green. Concurrent with the color change were rapid and dramatic reductions in gross photosynthesis and in the resultant high porewater oxygen concentrations in the surface layers of the mats. The depths at which both maximum gross photosynthesis and maximum oxygen concentrations occurred were displaced downward. In contrast, gross photosynthesis in the deeper layers of the mats increased in response to UV B incident upon the surface. The cessation of exposure to UV B partially reversed all of these changes. Taken together, these responses suggest that photoautotrophic members of the mat community, most likely the dominant cyanobacterium Microcoleus chthonoplastes, were migrating in response to the added UV B. The migration phenomenon was also observed in response to increases in visible radiation and UV A, but UV B was ca. 100-fold more effective than visible radiation and ca. 20-fold more effective than UV A in provoking the response. Migrating microorganisms within this mat are apparently able to sense UV B directly and respond behaviorally to limit their exposure to UV. Because of strong vertical gradients of light and dissolved substances in microbial mats, the migration and the resultant vertical redistribution of photosynthetic activity have important consequences for both the photobiology of the cyanobacteria and the net primary productivity of the mat ecosystem
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El Gohary, Mohammed I.; El Hady, Bothaina M. Abd; Saeed, Aziza A. Al; Tolba, Emad; El Rashedi, Ahlam M. I.; Saleh, Safaa
2018-06-01
Loading of anticancer drugs into electrospun fiber matrices is a portentous approach for clinical treatment of diseased tissues or organs. In this study, doxorubicin hydrochloride (DOX) is added to silica nanoparticles () during the formation of via the sol-gel approach. The obtained nanoparticles are then added to poly(-caprolactone) (PCL) and poly(ethylene oxide) (PEO) blend before electrospinning process via different methods. The effects of DOX addition as a free form or as nanoparticles on physical and chemical properties of obtained PCL-PEO fibers, as well as release profiles are evaluated to give a continual DOX release for several days. The morphology observed with scanning electron microscope (FESEM) revealed significant changes in the average diameter of obtained fibers ranging from 2164 nm to 659 nm and distribution of drug-loaded nanoparticles in the final mats according to the mode of additions. With the same manner, the releasing performances of obtained mats are quite different. Therefore, fabrication of drug loaded mats would offer a powerful approach to minimize serious side effects for clinical patients and allows us to control the drug concentration in the bloodstream.
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Dietary n-3 polyunsaturated fatty acids (PUFA) are associated with decreased plasma homocysteine (Hcy), an important biomarker for cardiovascular disease. Methionine adenosyltransferase (MAT1A) is an enzyme involved in formation of form S-adenosylmethionine during methionine metabolism. The objectiv...
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Coastal microbial mats: the physiology of a small-scale ecosystem
Stal, L.J.
2001-01-01
Coastal inter-tidal sandy sediments, salt marshes and mangrove forests often support the development of microbial mats. Microbial mats are complex associations of one or several functional groups of microorganisms and their formation usually starts with the growth of a cyanobacterial population on a
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Directory of Open Access Journals (Sweden)
Lukasz Drewniak
2016-08-01
Full Text Available Two microbial mats found inside two old (gold and uranium mines in Zloty Stok and Kowary located in SW Poland seem to form a natural barrier that traps heavy metals leaking from dewatering systems. We performed complex physiological and metagenomic analyses to determine which microorganisms are the main driving agents responsible for self-purification of the mine waters and identify metabolic processes responsible for the observed features. SEM and energy dispersive X-ray microanalysis showed accumulation of heavy metals on the mat surface, whereas, sorption experiments showed that neither microbial mats were completely saturated with heavy metals present in the mine waters, indicating that they have a large potential to absorb significant quantities of metal. The metagenomic analysis revealed that Methylococcaceae and Methylophilaceae families were the most abundant in both communities, moreover, it strongly suggest that backbones of both mats were formed by filamentous bacteria, such as Leptothrix, Thiothrix, and Beggiatoa. The Kowary bacterial community was enriched with the Helicobacteraceae family, whereas the Zloty Stok community consist mainly of Sphingomonadaceae, Rhodobacteraceae, and Caulobacteraceae families. Functional (culture-based and metagenome (sequence-based analyses showed that bacteria involved in immobilization of heavy metals, rather than those engaged in mobilization, were the main driving force within the analyzed communities. In turn, a comparison of functional genes revealed that the biofilm formation and heavy metal resistance functions are more desirable in microorganisms engaged in water purification than the ability to utilize heavy metals in the respiratory process (oxidation-reduction. These findings provide insight on the activity of bacteria leading, from biofilm formation to self-purification, of mine waters contaminated with heavy metals
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Comparison of the active and resident community of a coastal microbial mat
Cardoso, Daniela Clara; Sandionigi, Anna; Cretoiu, Mariana Silvia; Casiraghi, Maurizio; Stal, Lucas; Bolhuis, Henk
2017-01-01
Coastal microbial mats form a nearly closed micro-scale ecosystem harboring a complex microbial community. Previous DNA based analysis did not necessarily provide information about the active fraction of the microbial community because it includes dormant, inactive cells as well as a potential stable pool of extracellular DNA. Here we focused on the active microbial community by comparing 16S rRNA sequences obtained from the ribosomal RNA pool with gene sequences obtained from the DNA fractio...
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Low-Light Anoxygenic Photosynthesis and Fe-S-Biogeochemistry in a Microbial Mat
Directory of Open Access Journals (Sweden)
Sebastian Haas
2018-04-01
Full Text Available We report extremely low-light-adapted anoxygenic photosynthesis in a thick microbial mat in Magical Blue Hole, Abaco Island, The Bahamas. Sulfur cycling was reduced by iron oxides and organic carbon limitation. The mat grows below the halocline/oxycline at 30 m depth on the walls of the flooded sinkhole. In situ irradiance at the mat surface on a sunny December day was between 0.021 and 0.084 μmol photons m-2 s-1, and UV light (<400 nm was the most abundant part of the spectrum followed by green wavelengths (475–530 nm. We measured a light-dependent carbon uptake rate of 14.5 nmol C cm-2 d-1. A 16S rRNA clone library of the green surface mat layer was dominated (74% by a cluster (>97% sequence identity of clones affiliated with Prosthecochloris, a genus within the green sulfur bacteria (GSB, which are obligate anoxygenic phototrophs. Typical photopigments of brown-colored GSB, bacteriochlorophyll e and (β-isorenieratene, were abundant in mat samples and their absorption properties are well-adapted to harvest light in the available green and possibly even UV-A spectra. Sulfide from the water column (3–6 μmol L-1 was the main source of sulfide to the mat as sulfate reduction rates in the mats were very low (undetectable-99.2 nmol cm-3 d-1. The anoxic water column was oligotrophic and low in dissolved organic carbon (175–228 μmol L-1. High concentrations of pyrite (FeS2; 1–47 μmol cm-3 together with low microbial process rates (sulfate reduction, CO2 fixation indicate that the mats function as net sulfide sinks mainly by abiotic processes. We suggest that abundant Fe(III (4.3–22.2 μmol cm-3 is the major source of oxidizing power in the mat, and that abiotic Fe-S-reactions play the main role in pyrite formation. Limitation of sulfate reduction by low organic carbon availability along with the presence of abundant sulfide-scavenging iron oxides considerably slowed down sulfur cycling in these mats.
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Tek, Ee Lin; Sundstrom, Joanna F; Gardner, Jennifer M; Oliver, Stephen G; Jiranek, Vladimir
2018-02-01
Commercially available active dried wine yeasts are regularly used by winemakers worldwide to achieve reliable fermentations and obtain quality wine. This practice has led to increased evidence of traces of commercial wine yeast in the vineyard, winery and uninoculated musts. The mechanism(s) that enables commercial wine yeast to persist in the winery environment and the influence to native microbial communities on this persistence is poorly understood. This study has investigated the ability of commercial wine yeasts to form biofilms and adhere to plastic. The results indicate that the biofilms formed by commercial yeasts consist of cells with a combination of different lifestyles (replicative and non-replicative) and growth modes including invasive growth, bud elongation, sporulation and a mat sectoring-like phenotype. Invasive growth was greatly enhanced on grape pulp regardless of strain, while adhesion on plastic varied between strains. The findings suggest a possible mechanism that allows commercial yeast to colonise and survive in the winery environment, which may have implications for the indigenous microbiota profile as well as the population profile in uninoculated fermentations if their dissemination is not controlled. © FEMS 2018. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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Choudhury, Arup; Dey, Baban; Sinha Mahapatra, Susanta; Kim, Doo-Won; Yang, Kap-Seung; Yang, Duck-Joo
2018-04-01
Nanostructured poly(m-aminophenol) (PmAP) coated freestanding carbon nanofiber (CNF) mats were fabricated through simple in situ rapid-mixing polymerization of m-aminophenol in the presence of a CNF mat for flexible solid-state supercapacitors. The surface compositions, morphology and pore structure of the hybrid mats were characterized by using various techniques, e.g., FTIR, Raman, XRD, FE-SEM, TEM, and N2 absorption. The results show that the PmAP nanoparticles were homogeneously deposited on CNF surfaces and formed a thin flexible hybrid mat, which were directly used to made electrodes for electrochemical analysis without using any binders or conductive additives. The electrochemical performances of the hybrid mats were easily tailored by varying the PmAP loading on a hybrid electrode. The PmAP/CNF-10 hybrid electrode with a relatively low PmAP loading (> 42 wt%) showed a high specific capacitance of 325.8 F g-1 and a volumetric capacitance of 273.6 F cm-3 at a current density of 0.5 A g-1, together with a specific capacitance retention of 196.2 F g-1 at 20 A g-1. The PmAP/CNF-10 hybrid electrode showed good cycling stability with 88.2% capacitance retention after 5000 cycles. A maximum energy density of 45.2 Wh kg-1 and power density of 20.4 kW kg-1 were achieved for the PmAP/CNF-10 hybrid electrode. This facile and cost-effective synthesis of a flexible binder-free PmAP/CNF hybrid mat with excellent capacitive performances encourages its possible commercial exploitation.
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[Other viral food poisoning (hepatitis A and E)].
Yano, Kunio
2012-08-01
Hepatitis A and E viruses are spread via the fecal-oral route. In the endemic area, restaurant and school outbreaks due to contaminated water or food have been reported. The clinical signs and symptoms in patients with typical hepatitis A and E are similar to those seen with other forms of acute viral hepatitis. Hepatitis A tends to be more severe when acquired at older ages. Hepatitis E appears to be relatively severe compared with hepatitis A. Although both hepatitis are self-limited illness, severe hepatits are rarely observed. Hepatitis A and E can be prevented by improved sanitary conditions, handwashing, heating foods appropriately. Avoidance of water and foods from endemic areas is also effective.
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Directory of Open Access Journals (Sweden)
Anna Namura-Ochalska
2011-01-01
Full Text Available In the initial phase of growth in an oligo-humotrophic lake, Cladium mariscus forms a dense and tall sawgrass bed invading the open water in the form of a floating mat. High densities of submerged evergreen perennial stems of C. mariscus, over two metres high and abundantly fruiting, ensure its persistence, and form a natural barrier to the invasion of other species. Dense mats of sawgrass are formed as a result of clonal and rhizome growth. Although diaspore production is abundant under natural conditions, only vegetative propagation of stems was observed. In different variants of the experiment only seeds wintering on stems of mother plants were capable of germinating. Hard seed coats had an important effect on the germination capacity of seeds.
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Huang, Rong; Deng, Hongbing; Cai, Tongjian; Zhan, Yingfei; Wang, Xiankai; Chen, Xuanxuan; Ji, Ailing; Lil, Xueyong
2014-07-01
Catalase, a kind of redox enzyme and generally recognized as an efficient agent for protecting cells against hydrogen peroxide (H2O2)-induced cytotoxicity. The immobilization of catalase was accomplished by depositing the positively charged chitosan and the negatively charged catalase on electrospun cellulose nanofibrous mats through electrospining and layer-by-layer (LBL) techniques. The morphology obtained from Field emission scanning electron microscopy (FE-SEM) indicated that more orderly arranged three-dimension (3D) structure and roughness formed with increasing the number of coating bilayers. Besides, the enzyme-immobilized nanofibrous mats were found with high enzyme loading and activity, moreover, X-ray photoelectron spectroscopy (XPS) results further demonstrated the successful immobilization of chitosan and catalase on cellulose nanofibers support. Furthermore, we evaluated the cytotoxicity induced by hydrogen peroxide in the Human umbilical vascular endothelial cells with or without pretreatment of nanofibrous mats by MTT assay, LDH activity and Flow cytometric evaluation, and confirmed the pronounced hydrogen peroxide-induced toxicity, but pretreatment of immobilized catalase reduced the cytotoxicity and protected cells against hydrogen peroxide-induced cytotoxic effects which were further demonstrated by scanning electron microscopy (SEM) and Transmission Electron Microscopy (TEM) images. The data pointed toward a role of catalase-immobilized nanofibrous mats in protecting cells against hydrogen peroxide-induced cellular damage and their potential application in biomedical field.
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Alpha Matting with KL-Divergence Based Sparse Sampling.
Karacan, Levent; Erdem, Aykut; Erdem, Erkut
2017-06-22
In this paper, we present a new sampling-based alpha matting approach for the accurate estimation of foreground and background layers of an image. Previous sampling-based methods typically rely on certain heuristics in collecting representative samples from known regions, and thus their performance deteriorates if the underlying assumptions are not satisfied. To alleviate this, we take an entirely new approach and formulate sampling as a sparse subset selection problem where we propose to pick a small set of candidate samples that best explains the unknown pixels. Moreover, we describe a new dissimilarity measure for comparing two samples which is based on KLdivergence between the distributions of features extracted in the vicinity of the samples. The proposed framework is general and could be easily extended to video matting by additionally taking temporal information into account in the sampling process. Evaluation on standard benchmark datasets for image and video matting demonstrates that our approach provides more accurate results compared to the state-of-the-art methods.
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MAT-DB - A database for nuclear energy related materials data
International Nuclear Information System (INIS)
Over, H.H.
2009-01-01
The web-enabled materials database (Mat-DB) of JRC-IE has a long-term history in storing materials test data resulting from European and international research projects. The database structure and the user-guidance has bee permanently updated improved and optimized. The database is implemented in the secure ODIN portal: https://odin.jrc.ec.europa.eu of JRC-IE. This architecture guarantees fast access to confidential and public data and documentation which are stored in an inter-related document management database (DoMa). It is a part of JRC's nuclear knowledge management. Mat-DB hosts the whole pool of IAEA surveillance data of reactor pressure vessel materials from different nuclear power plants of the member states. Mat-DB contains also thousands of European GEN IV reactor systems related R and D materials data which are an important basis for the evaluating and extrapolating design data for candidate materials and setting up design rules covering high temperature exposure, irradiation and corrosion. Those data and rules would match also fusion related components. Mat-DB covers thermo-mechanical and thermo-physical properties data of engineering alloys at low, elevated and high temperatures for base materials and joints, including irradiated materials for nuclear fission and fusion applications, thermal barrier coated materials for gas turbines and properties of corroded materials. The corrosion part refers to weight gain/loss data of high temperature exposed engineering alloys and ceramic materials. For each test type the database structure reflects international test standards and recommendations. Mat-DB features an extensive library of evaluation programs for web-enabled assessment of uniaxial creep, fatigue, crack growth and high temperature corrosion properties. Evaluations can be performed after data retrieval or independently of Mat-DB by transferring other materials data in a given format to the programs. The fast evaluation processes help the user to
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Rigid Polyurethane Foam Thermal Insulation Protected with Mineral Intumescent Mat
Directory of Open Access Journals (Sweden)
Kirpluks Mikelis
2014-12-01
Full Text Available One of the biggest disadvantages of rigid polyurethane (PU foams is its low thermal resistance, high flammability and high smoke production. Greatest advantage of this thermal insulation material is its low thermal conductivity (λ, which at 18-28 mW/(m•K is superior to other materials. To lower the flammability of PU foams, different flame retardants (FR are used. Usually, industrially viable are halogenated liquid FRs but recent trends in EU regulations show that they are not desirable any more. Main concern is toxicity of smoke and health hazard form volatiles in PU foam materials. Development of intumescent passive fire protection for foam materials would answer problems with flammability without using halogenated FRs. It is possible to add expandable graphite (EG into PU foam structure but this increases the thermal conductivity greatly. Thus, the main advantage of PU foam is lost. To decrease the flammability of PU foams, three different contents 3%; 9% and 15% of EG were added to PU foam formulation. Sample with 15% of EG increased λ of PU foam from 24.0 to 30.0 mW/(m•K. This paper describes the study where PU foam developed from renewable resources is protected with thermally expandable intumescent mat from Technical Fibre Products Ltd. (TFP as an alternative to EG added into PU material. TFP produces range of mineral fibre mats with EG that produce passive fire barrier. Two type mats were used to develop sandwich-type PU foams. Also, synergy effect of non-halogenated FR, dimethyl propyl phosphate and EG was studied. Flammability of developed materials was assessed using Cone Calorimeter equipment. Density, thermal conductivity, compression strength and modulus of elasticity were tested for developed PU foams. PU foam morphology was assessed from scanning electron microscopy images.
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Müller, Werner E.G.; Tolba, Emad; Dorweiler, Bernhard; Schröder, Heinz C.; Diehl-Seifert, Bärbel; Wang, Xiaohong
2015-01-01
Background While electrospun materials have been frequently used in tissue engineering no wound dressings exist that significantly improved wound healing effectively. Methods We succeeded to fabricate three-dimensional (3D) electrospun poly(D,l-lactide) (PLA) fiber mats into which nanospheres, formed from amorphous calcium polyphosphate (polyP) nanoparticles (NP) and encapsulated retinol (“retinol/aCa-polyP-NS” nanospheres [NS]), had been incorporated. Results Experiments with MC3T3-E1 cells ...
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Biomedical Applications of Antibacterial Nanofiber Mats Made of Electrospinning with Wire Electrodes
Directory of Open Access Journals (Sweden)
Yi-Jun Pan
2016-02-01
Full Text Available Twisted stainless steel wires are used as wire electrodes for electrospinning the polyvinyl alcohol (PVA/zinc citrate nanofiber mats. The morphology and diameter of the nanofibers in PVA/zinc citrate nanofiber mats are evaluated. We measured the antibacterial efficacy against Staphylococcus aureus (S. aureus and Escherichia coli (E. coli of the nanofiber mats. We also examined the cell adhesion affinity of mammalian tissue culture cells on these nanofiber mats. Our results indicate that an increase in zinc citrate increases the viscosity and electrical conductivity of PVA solution. In addition, increasing zinc citrate results in a smaller diameter of nanofibers that reaches below 100 nm. According to the antibacterial test results, increasing zinc citrate enlarges the inhibition zone of S. aureus but only has a bacteriostatic effect against E. coli. Finally, cell adhesion test results indicate that all nanofiber mats have satisfactory cell attachment regardless of the content of zinc citrate.
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Energy Technology Data Exchange (ETDEWEB)
Mobberley, Jennifer M.; Lindemann, Stephen R.; Bernstein, Hans C.; Moran, James J.; Renslow, Ryan S.; Babauta, Jerome; Hu, Dehong; Beyenal, Haluk; Nelson, William C.
2017-03-21
Phototrophic mat communities are model ecosystems for studying energy cycling and elemental transformations because complete biogeochemical cycles occur over millimeter-to-centimeter scales. Characterization of energy and nutrient capture within hypersaline phototrophic mats has focused on specific processes and organisms, however little is known about community-wide distribution of and linkages between these processes. To investigate energy and macronutrient capture and flow through a structured community, the spatial and organismal distribution of metabolic functions within a compact hypersaline mat community from Hot Lake have been broadly elucidated through species-resolved metagenomics and geochemical, microbial diversity, and metabolic gradient measurements. Draft reconstructed genomes of abundant organisms revealed three dominant cyanobacterial populations differentially distributed across the top layers of the mat suggesting niche separation along light and oxygen gradients. Many organisms contained diverse functional profiles, allowing for metabolic response to changing conditions within the mat. Organisms with partial nitrogen and sulfur metabolisms were widespread indicating dependence upon metabolite exchange. In addition, changes in community spatial structure were observed over the diel. These results indicate that organisms within the mat community have adapted to the temporally dynamic environmental gradients in this hypersaline mat through metabolic flexibility and fluid syntrophic interactions, including shifts in spatial arrangements.
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Modification of PLGA Nanofibrous Mats by Electron Beam Irradiation for Soft Tissue Regeneration
Directory of Open Access Journals (Sweden)
Jae Baek Lee
2015-01-01
Full Text Available Biodegradable poly(lactide-co-glycolide (PLGA has found widespread use in modern medical practice. However, the degradation rate of PLGA should be adjusted for specific biomedical applications such as tissue engineering, drug delivery, and surgical implantation. This study focused on the effect of electron beam radiation on nanofibrous PLGA mats in terms of physical properties and degradation behavior with cell proliferation. PLGA nanofiber mats were prepared by electrospinning, and electron beam was irradiated at doses of 50, 100, 150, 200, 250, and 300 kGy. PLGA mats showed dimensional integrity after electron beam irradiation without change of fiber diameter. The degradation behavior of a control PLGA nanofiber (0 kGy and electron beam-irradiated PLGA nanofibers was analyzed by measuring the molecular weight, weight loss, change of chemical structure, and fibrous morphology. The molecular weight of the PLGA nanofibers decreased with increasing electron beam radiation dose. The mechanical properties of the PLGA nanofibrous mats were decreased with increasing electron beam irradiation dose. Cell proliferation behavior on all electron beam irradiated PLGA mats was similar to the control PLGA mats. Electron beam irradiation of PLGA nanofibrous mats is a potentially useful approach for modulating the biodegradation rate of tissue-specific nonwoven nanofibrous scaffolds, specifically for soft tissue engineering applications.
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The contribution of microbial mats to the arsenic geochemistry of an ancient gold mine
International Nuclear Information System (INIS)
Drewniak, Lukasz; Maryan, Natalia; Lewandowski, Wiktor; Kaczanowski, Szymon; Sklodowska, Aleksandra
2012-01-01
The ancient Zloty Stok (SW Poland) gold mine is such an environment, where different microbial communities, able to utilize inorganic arsenic species As(III) and As(V), are found. The purpose of the present study was to (i) estimate prokaryotic diversity in the microbial mats in bottom sediments of this gold mine, (ii) identify microorganisms that can metabolize arsenic, and (iii) estimate their potential role in the arsenic geochemistry of the mine and in the environment. The oxidation/reduction experiments showed that the microbial mat community may significantly contribute to arsenic contamination in groundwater. The presence of both arsenite oxidizing and dissimilatory arsenate reducing bacteria in the mat was confirmed by the detection of arsenite oxidase and dissimilatory arsenate reductase genes, respectively. This work also demonstrated that microorganisms utilizing other compounds that naturally co-occur with arsenic are present within the microbial mat community and may contribute to the arsenic geochemistry in the environment. - Highlights: ► The microbial mats from this ancient gold mine are highly diverse community. ► As(III) oxidizing and As(V) reducing bacteria are present in the mats. ► As redox transformations are linked to the metabolism of microbial mats bacteria. ► Microbial mats play a crucial role in the As biogeochemical cycle within the mine. - The microbial mats from this ancient gold mine can mediate oxidation/reduction reaction of arsenic and in this way may significantly contribute to arsenic contamination in groundwater.
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Matérn-based nonstationary cross-covariance models for global processes
Jun, Mikyoung
2014-01-01
-covariance models, based on the Matérn covariance model class, that are suitable for describing prominent nonstationary characteristics of the global processes. In particular, we seek nonstationary versions of Matérn covariance models whose smoothness parameters
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Energy Technology Data Exchange (ETDEWEB)
Zhong, Yi [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Key Laboratory of Science & Technology of Eco-Textile, Ministry of Education, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai (China); Leung, Victor; Yuqin Wan, Lynn [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Dutz, Silvio [Institut für Biomedizinische Technik und Informatik, Technische Universität Ilmenau (Germany); Department of Nano Biophotonics, Leibniz Institute of Photonic Technology, Jena (Germany); Ko, Frank K., E-mail: frank.ko@ubc.ca [Department of Materials Engineering, University of British Columbia, Vancouver (Canada); Häfeli, Urs O., E-mail: urs.hafeli@ubc.ca [Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver (Canada)
2015-04-15
A solvothermal process was adopted to produce hydrophilic magnetite (Fe{sub 3}O{sub 4}) nanoparticles which were subsequently emulsified with a chloroform/methanol (70/30 v/v) solution of poly(caprolactone) (PCL) and then electrospun into a 0.2 mm thick PCL mat. The magnetic heating of the mats at a field amplitude of 25 kA/m and frequency of 400 kHz exhibited promising efficiency for magnetic hyperthermia, with a specific absorption rate of about 40 W/g for the magnetic mat. The produced heat was used to melt the magnetic mat onto the surrounding non-magnetic polymer mat from within, without destroying the nanostructure of the non-magnetic polymer more than 0.5 mm away. Magnetic nanofibre mats might thus be useful for internal heat sealing applications, and potentially also for thermotherapy.
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Directory of Open Access Journals (Sweden)
Estela C. Mlewski
2018-05-01
Full Text Available Stromatolites are organo-sedimentary structures that represent some of the oldest records of the early biosphere on Earth. Cyanobacteria are considered as a main component of the microbial mats that are supposed to produce stromatolite-like structures. Understanding the role of cyanobacteria and associated microorganisms on the mineralization processes is critical to better understand what can be preserved in the laminated structure of stromatolites. Laguna Negra (Catamarca, Argentina, a high-altitude hypersaline lake where stromatolites are currently formed, is considered as an analog environment of early Earth. This study aimed at characterizing carbonate precipitation within microbial mats and associated oncoids in Laguna Negra. In particular, we focused on carbonated black pustular mats. By combining Confocal Laser Scanning Microscopy, Scanning Electron Microscopy, Laser Microdissection and Whole Genome Amplification, Cloning and Sanger sequencing, and Focused Ion Beam milling for Transmission Electron Microscopy, we showed that carbonate precipitation did not directly initiate on the sheaths of cyanobacterial Rivularia, which dominate in the mat. It occurred via organo-mineralization processes within a large EPS matrix excreted by the diverse microbial consortium associated with Rivularia where diatoms and anoxygenic phototrophic bacteria were particularly abundant. By structuring a large microbial consortium, Rivularia should then favor the formation of organic-rich laminations of carbonates that can be preserved in stromatolites. By using Fourier Transform Infrared spectroscopy and Synchrotron-based deep UV fluorescence imaging, we compared laminations rich in structures resembling Rivularia to putatively chemically-precipitated laminations in oncoids associated with the mats. We showed that they presented a different mineralogy jointly with a higher content in organic remnants, hence providing some criteria of biogenicity to be searched
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Investigation of needleless electrospun PAN nanofiber mats
Sabantina, Lilia; Mirasol, José Rodríguez; Cordero, Tomás; Finsterbusch, Karin; Ehrmann, Andrea
2018-04-01
Polyacrylonitrile (PAN) can be spun from a nontoxic solvent (DMSO, dimethyl sulfoxide) and is nevertheless waterproof, opposite to the biopolymers which are spinnable from aqueous solutions. This makes PAN an interesting material for electrospinning nanofiber mats which can be used for diverse biotechnological or medical applications, such as filters, cell growth, wound healing or tissue engineering. On the other hand, PAN is a typical base material for producing carbon nanofibers. Nevertheless, electrospinning PAN necessitates convenient spinning parameters to create nanofibers without too many membranes or agglomerations. Thus we have studied the influence of spinning parameters on the needleless electrospinning process of PAN dissolved in DMSO and the resulting nanofiber mats.
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Optical diagnostic of hepatitis B (HBV) and C (HCV) from human blood serum using Raman spectroscopy
International Nuclear Information System (INIS)
Anwar, Shahzad; Firdous, Shamaraz
2015-01-01
Hepatitis is the second most common disease worldwide with half of the cases arising in the developing world. The mortality associated with hepatitis B and C can be reduced if the disease is detected at the early stages of development. The aim of this study was to investigate the potential of Raman spectroscopy as a diagnostic tool to detect biochemical changes accompanying hepatitis progression. Raman spectra were acquired from 20 individuals with six hepatitis B infected patients, six hepatitis C infected patients and eight healthy patients in order to gain an insight into the determination of biochemical changes for early diagnostic. The human blood serum was examined at a 532 nm excitation laser source. Raman characteristic peaks were observed in normal sera at 1006, 1157 and 1513 cm −1 , while in the case of hepatitis B and C these peaks were found to be blue shifted with decreased intensity. New Raman peaks appeared in HBV and HCV infected sera at 1194, 1302, 844, 905, 1065 and 1303 cm −1 respectively. A Mat lab subroutine and frequency domain filter program is developed and applied to signal processing of Raman scattering data. The algorithms have been successfully applied to remove the signal noise found in experimental scattering signals. The results show that Raman spectroscopy displays a high sensitivity to biochemical changes in blood sera during disease progression resulting in exceptional prediction accuracy when discriminating between normal and malignant. Raman spectroscopy shows enormous clinical potential as a rapid non-invasive diagnostic tool for hepatitis and other infectious diseases. (letter)
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Optical diagnostic of hepatitis B (HBV) and C (HCV) from human blood serum using Raman spectroscopy
Anwar, Shahzad; Firdous, Shamaraz
2015-06-01
Hepatitis is the second most common disease worldwide with half of the cases arising in the developing world. The mortality associated with hepatitis B and C can be reduced if the disease is detected at the early stages of development. The aim of this study was to investigate the potential of Raman spectroscopy as a diagnostic tool to detect biochemical changes accompanying hepatitis progression. Raman spectra were acquired from 20 individuals with six hepatitis B infected patients, six hepatitis C infected patients and eight healthy patients in order to gain an insight into the determination of biochemical changes for early diagnostic. The human blood serum was examined at a 532 nm excitation laser source. Raman characteristic peaks were observed in normal sera at 1006, 1157 and 1513 cm-1, while in the case of hepatitis B and C these peaks were found to be blue shifted with decreased intensity. New Raman peaks appeared in HBV and HCV infected sera at 1194, 1302, 844, 905, 1065 and 1303 cm-1 respectively. A Mat lab subroutine and frequency domain filter program is developed and applied to signal processing of Raman scattering data. The algorithms have been successfully applied to remove the signal noise found in experimental scattering signals. The results show that Raman spectroscopy displays a high sensitivity to biochemical changes in blood sera during disease progression resulting in exceptional prediction accuracy when discriminating between normal and malignant. Raman spectroscopy shows enormous clinical potential as a rapid non-invasive diagnostic tool for hepatitis and other infectious diseases.
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Results of steroid-based therapy for the hepatitis C-autoimmune hepatitis overlap syndrome.
Schiano, T D; Te, H S; Thomas, R M; Hussain, H; Bond, K; Black, M
2001-10-01
Overlap syndromes in which persons manifest clinical, histological, or immunological features of both hepatitis C infection and autoimmune hepatitis are well described. The discordant forms of treatment for hepatitis C and autoimmune hepatitis have made medical management of these patients difficult. We report our experience in using corticosteroids as first line therapy for the hepatitis C-autoimmune hepatitis overlap syndrome. Seven patients with this overlap syndrome (diagnosis based on the presence of serum hepatitis C antibody by RIBA and serum hepatitis C RNA by polymerase chain reaction, and serum hypergammaglobulinemia, elevated ANA or ASMA titers, or histological findings consistent with autoimmune hepatitis) were treated with prednisone with or without azathioprine or cyclosporine, and followed for a median duration of 44.5 months. Five patients (71%) showed improvement of median serum ALT level from 162 U/L to 38 U/L (p = 0.04) and median serum gamma-globulin from 2.1 g/dl to 1.4 g/dl (p = 0.04) by 6 months of therapy. The mean modified histological activity index score also decreased from 11.4 +/- 2.5 to 6.6 +/- 2.6 (p = 0.04) by at least 1 yr of therapy. One patient discontinued prednisone while taking azathioprine and experienced a rebound elevation of serum ALT that did not respond to retreatment with prednisone. Antiviral therapy was subsequently administered and resulted in biochemical and virologic response. Hepatitis C virus RNA remained detectable in all other patients. Corticosteroids are beneficial as a first line therapy for some patients with the hepatitis C-autoimmune overlap syndrome, resulting in appreciable biochemical and histological response but without viral eradication.
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Bolton, Melvin D; de Jonge, Ronnie; Inderbitzin, Patrik; Liu, Zhaohui; Birla, Keshav; Van de Peer, Yves; Subbarao, Krishna V; Thomma, Bart P H J; Secor, Gary A
2014-01-01
Dothideomycetes is one of the most ecologically diverse and economically important classes of fungi. Sexual reproduction in this group is governed by mating type (MAT) genes at the MAT1 locus. Self-sterile (heterothallic) species contain one of two genes at MAT1 (MAT1-1-1 or MAT1-2-1) and only isolates of opposite mating type are sexually compatible. In contrast, self-fertile (homothallic) species contain both MAT genes at MAT1. Knowledge of the reproductive capacities of plant pathogens are of particular interest because recombining populations tend to be more difficult to manage in agricultural settings. In this study, we sequenced MAT1 in the heterothallic Dothideomycete fungus Cercospora beticola to gain insight into the reproductive capabilities of this important plant pathogen. In addition to the expected MAT gene at MAT1, each isolate contained fragments of both MAT1-1-1 and MAT1-2-1 at ostensibly random loci across the genome. When MAT fragments from each locus were manually assembled, they reconstituted MAT1-1-1 and MAT1-2-1 exons with high identity, suggesting a retroposition event occurred in a homothallic ancestor in which both MAT genes were fused. The genome sequences of related taxa revealed that MAT gene fragment pattern of Cercospora zeae-maydis was analogous to C. beticola. In contrast, the genome of more distantly related Mycosphaerella graminicola did not contain MAT fragments. Although fragments occurred in syntenic regions of the C. beticola and C. zeae-maydis genomes, each MAT fragment was more closely related to the intact MAT gene of the same species. Taken together, these data suggest MAT genes fragmented after divergence of M. graminicola from the remaining taxa, and concerted evolution functioned to homogenize MAT fragments and MAT genes in each species. Published by Elsevier Inc.
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Litt, Jonathan S. (Compiler)
2018-01-01
NASA Glenn Research Center hosted a Users' Workshop on the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) on August 21, 2017. The objective of this workshop was to update the user community on the latest features of T-MATS, and to provide a forum to present work performed using T-MATS. Presentations highlighted creative applications and the development of new features and libraries, and emphasized the flexibility and simulation power of T-MATS.
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Perfect simulation and moment properties for the Matérn type III process
DEFF Research Database (Denmark)
Møller, Jesper; Huber, Mark L.; Wolpert, Robert L.
2010-01-01
In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound on the m......In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Matérn III process within a bounded window in , fully accounting for edge effects. A simple upper bound...
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Glucocorticosteroids for people with alcoholic hepatitis
DEFF Research Database (Denmark)
Pavlov, Chavdar S; Varganova, Daria L; Casazza, Giovanni
2017-01-01
BACKGROUND: Alcoholic hepatitis is a form of alcoholic liver disease, characterised by steatosis, necroinflammation, fibrosis, and potential complications to the liver disease. Typically, alcoholic hepatitis presents in people between 40 and 50 years of age. Alcoholic hepatitis can be resolved...... if people abstain from drinking, but the risk of death will depend on the severity of the liver damage and abstinence from alcohol. Glucocorticosteroids are used as anti-inflammatory drugs for people with alcoholic hepatitis. Glucocorticosteroids have been studied extensively in randomised clinical trials...... in order to assess their benefits and harms. However, the results have been contradictory. OBJECTIVES: To assess the benefits and harms of glucocorticosteroids in people with alcoholic hepatitis. SEARCH METHODS: We identified trials through electronic searches in Cochrane Hepato-Biliary's (CHB) Controlled...
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Biogeochemistry of an iron-rich hypersaline microbial mat (Camargue, France).
Wieland, A; Zopfi, J; Benthien, M; Kühl, M
2005-01-01
In situ microsensor measurements were combined with biogeochemical methods to determine oxygen, sulfur, and carbon cycling in microbial mats growing in a solar saltern (Salin-de-Giraud, France). Sulfate reduction rates closely followed the daily temperature changes and were highest during the day at 25 degrees C and lowest during the night at 11 degrees C, most probably fueled by direct substrate interactions between cyanobacteria and sulfate-reducing bacteria. Sulfate reduction was the major mineralization process during the night and the contribution of aerobic respiration to nighttime DIC production decreased. This decrease of aerobic respiration led to an increasing contribution of sulfide (and iron) oxidation to nighttime O2 consumption. A peak of elemental sulfur in a layer of high sulfate reduction at low sulfide concentration underneath the oxic zone indicated anoxygenic photosynthesis and/or sulfide oxidation by iron, which strongly contributed to sulfide consumption. We found a significant internal carbon cycling in the mat, and sulfate reduction directly supplied DIC for photosynthesis. The mats were characterized by a high iron content of 56 micromol Fe cm(-3), and iron cycling strongly controlled the sulfur cycle in the mat. This included sulfide precipitation resulting in high FeS contents with depth, and reactions of iron oxides with sulfide, especially after sunset, leading to a pronounced gap between oxygen and sulfide gradients and an unusual persistence of a pH peak in the uppermost mat layer until midnight.
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Shen, Shihao; Park, Juw Won; Lu, Zhi-xiang; Lin, Lan; Henry, Michael D; Wu, Ying Nian; Zhou, Qing; Xing, Yi
2014-12-23
Ultra-deep RNA sequencing (RNA-Seq) has become a powerful approach for genome-wide analysis of pre-mRNA alternative splicing. We previously developed multivariate analysis of transcript splicing (MATS), a statistical method for detecting differential alternative splicing between two RNA-Seq samples. Here we describe a new statistical model and computer program, replicate MATS (rMATS), designed for detection of differential alternative splicing from replicate RNA-Seq data. rMATS uses a hierarchical model to simultaneously account for sampling uncertainty in individual replicates and variability among replicates. In addition to the analysis of unpaired replicates, rMATS also includes a model specifically designed for paired replicates between sample groups. The hypothesis-testing framework of rMATS is flexible and can assess the statistical significance over any user-defined magnitude of splicing change. The performance of rMATS is evaluated by the analysis of simulated and real RNA-Seq data. rMATS outperformed two existing methods for replicate RNA-Seq data in all simulation settings, and RT-PCR yielded a high validation rate (94%) in an RNA-Seq dataset of prostate cancer cell lines. Our data also provide guiding principles for designing RNA-Seq studies of alternative splicing. We demonstrate that it is essential to incorporate biological replicates in the study design. Of note, pooling RNAs or merging RNA-Seq data from multiple replicates is not an effective approach to account for variability, and the result is particularly sensitive to outliers. The rMATS source code is freely available at rnaseq-mats.sourceforge.net/. As the popularity of RNA-Seq continues to grow, we expect rMATS will be useful for studies of alternative splicing in diverse RNA-Seq projects.
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Directory of Open Access Journals (Sweden)
Jackson Z Lee
2014-02-01
Full Text Available Past studies of hydrogen cycling in hypersaline microbial mats have shown an active nighttime cycle, with production largely from Cyanobacteria and consumption from sulfate-reducing bacteria (SRB. However, the mechanisms and magnitude of hydrogen cycling have not been extensively studied. Two mats types near Guerrero Negro, Mexico -- permanently submerged Microcoleus microbial mats (GN-S, and intertidal Lyngbya microbial mats (GN-I -- were used in microcosm diel manipulation experiments with 3-(3,4-dichlorophenyl-1,1-dimethylurea (DCMU, molybdate, ammonium addition, and physical disruption to understand the processes responsible for hydrogen cycling between mat microbes. Across microcosms, H2 production occurred under dark anoxic conditions with simultaneous production of a suite of organic acids. H2 production was not significantly affected by inhibition of nitrogen fixation, but rather appears to result from constitutive fermentation of photosynthetic storage products by oxygenic phototrophs. Comparison to accumulated glycogen and to CO2 flux indicated that, in the GN-I mat, fermentation released almost all of the carbon fixed via photosynthesis during the preceding day, primarily as organic acids. Across mats, although oxygenic and anoxygenic phototrophs were detected, cyanobacterial [NiFe]-hydrogenase transcripts predominated. Molybdate inhibition experiments indicated that SRBs from a wide distribution of dsrA phylotypes were responsible for H2 consumption. Incubation with 13C-acetate and nanoSIMS (secondary ion mass-spectrometry indicated higher uptake in both Chloroflexi and SRBs relative to other filamentous bacteria. These manipulations and diel incubations confirm that Cyanobacteria were the main fermenters in Guerrero Negro mats and that the net flux of nighttime fermentation byproducts (not only hydrogen was largely regulated by the interplay between Cyanobacteria, SRBs, and Chloroflexi.
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DEFF Research Database (Denmark)
CASTENHOLZ, RW; JØRGENSEN, BB; DAMELIO, E.
1991-01-01
and predominant population which was spread over the mat surface during darkness and on overcast days ( 300 W m-2), O. boryana disappeared almost entirely from the mat surface to a position of about 1 mm below the surface pellicle of the mat. O2, sulfide, and pH microelectrodes inserted into excised mat cores...... photosynthesis of O. boryana occurred. This capability was confirmed for O. boryana by [C-14]-photoincorporation and sulfide-microelectrode experiments. Forced exposure to high irradiance levels (500-700 W m-2) was inhibitory to oxygenic photosynthesis in O. boryana, but these intensities impinging on mats...
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Temperature dependent transport and dielectric properties of cadmium titanate nanofiber mats
Directory of Open Access Journals (Sweden)
Z. Imran
2013-03-01
Full Text Available We investigate electrical and dielectric properties of cadmium titanate (CdTiO3 nanofiber mats prepared by electrospinning. The nanofibers were polycrystalline having diameter ∼50 nm-200 nm, average length ∼100 μm and crystallite size ∼25 nm. Alternating current impedance measurements were carried out from 318 K – 498 K. The frequency of ac signal was varied from 2 – 105 Hz. The complex impedance plots revealed two depressed semicircular arcs indicating the bulk and interface contribution to overall electrical behavior of nanofiber mats. The bulk resistance was found to increase with decrease in temperature exhibiting typical semiconductor like behavior. The modulus analysis shows the non-Debye type conductivity relaxation in nanofiber mats. The ac conductivity spectrum obeyed the Jonscher power law. Analysis of frequency dependent ac conductivity revealed presence of the correlated barrier hopping (CBH in nanofiber mats over the entire temperature range.
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A niche for cyanobacteria producing chlorophyll f within a microbial mat.
Ohkubo, Satoshi; Miyashita, Hideaki
2017-10-01
Acquisition of additional photosynthetic pigments enables photosynthetic organisms to survive in particular niches. To reveal the ecological significance of chlorophyll (Chl) f, we investigated the distribution of Chl and cyanobacteria within two microbial mats. In a 7-mm-thick microbial mat beneath the running water of the Nakabusa hot spring, Japan, Chl f was only distributed 4.0-6.5 mm below the surface, where the intensity of far-red light (FR) was higher than that of photosynthetically active radiation (PAR). In the same mat, two ecotypes of Synechococcus and two ecotypes of Chl f-producing Leptolyngbya were detected in the upper and deeper layers, respectively. Only the Leptolyngbya strains could grow when FR was the sole light source. These results suggest that the deeper layer of the microbial mat was a habitat for Chl f-producing cyanobacteria, and Chl f enabled them to survive in a habitat with little PAR.
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Sway Area and Velocity Correlated With MobileMat Balance Error Scoring System (BESS) Scores.
Caccese, Jaclyn B; Buckley, Thomas A; Kaminski, Thomas W
2016-08-01
The Balance Error Scoring System (BESS) is often used for sport-related concussion balance assessment. However, moderate intratester and intertester reliability may cause low initial sensitivity, suggesting that a more objective balance assessment method is needed. The MobileMat BESS was designed for objective BESS scoring, but the outcome measures must be validated with reliable balance measures. Thus, the purpose of this investigation was to compare MobileMat BESS scores to linear and nonlinear measures of balance. Eighty-eight healthy collegiate student-athletes (age: 20.0 ± 1.4 y, height: 177.7 ± 10.7 cm, mass: 74.8 ± 13.7 kg) completed the MobileMat BESS. MobileMat BESS scores were compared with 95% area, sway velocity, approximate entropy, and sample entropy. MobileMat BESS scores were significantly correlated with 95% area for single-leg (r = .332) and tandem firm (r = .474), and double-leg foam (r = .660); and with sway velocity for single-leg (r = .406) and tandem firm (r = .601), and double-leg (r = .575) and single-leg foam (r = .434). MobileMat BESS scores were not correlated with approximate or sample entropy. MobileMat BESS scores were low to moderately correlated with linear measures, suggesting the ability to identify changes in the center of mass-center of pressure relationship, but not higher-order processing associated with nonlinear measures. These results suggest that the MobileMat BESS may be a clinically-useful tool that provides objective linear balance measures.
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Cantera Integration with the Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS)
Lavelle, Thomas M.; Chapman, Jeffryes W.; May, Ryan D.; Litt, Jonathan S.; Guo, Ten-Huei
2014-01-01
NASA Glenn Research Center (GRC) has recently developed a software package for modeling generic thermodynamic systems called the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS). T-MATS is a library of building blocks that can be assembled to represent any thermodynamic system in the Simulink (The MathWorks, Inc.) environment. These elements, along with a Newton Raphson solver (also provided as part of the T-MATS package), enable users to create models of a wide variety of systems. The current version of T-MATS (v1.0.1) uses tabular data for providing information about a specific mixture of air, water (humidity), and hydrocarbon fuel in calculations of thermodynamic properties. The capabilities of T-MATS can be expanded by integrating it with the Cantera thermodynamic package. Cantera is an object-oriented analysis package that calculates thermodynamic solutions for any mixture defined by the user. Integration of Cantera with T-MATS extends the range of systems that may be modeled using the toolbox. In addition, the library of elements released with Cantera were developed using MATLAB native M-files, allowing for quicker prototyping of elements. This paper discusses how the new Cantera-based elements are created and provides examples for using T-MATS integrated with Cantera.
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Effects of tacky mat contamination on bond degradation for Chemlok/liner and NBR/liner bonds
Padilla, A. M.
1989-01-01
Tacky mats are placed by the rubber lay-up areas for the solid rocket motor segments. These mats dust off the shoes prior to entering the platform where the lay-up work is performed. The possibility exists that a tacky mat could be touched with gloved hands prior to handling the uncured nitride butadiene rubber (NBR). Tests were run to determine if NBR were accidentally touched would there be any degradation of the liner/NBR bond. The tacky mats were judged solely on the basis of bond degradation caused by either direct or indirect contamination. Test results all indicate that there was no notable NBR/Chemlok or liner/NBR bond degradation on samples that came into contact with the tacky mat material. Testing procedures are described. The tacky mat adhesive composition does not contain fluorocarbons or release agents that would affect bonding.
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Energy Technology Data Exchange (ETDEWEB)
Kumar, Dhananjay [Plant Molecular Biology and Plant Physiology Lab, Lab no. 114, School of Life Sciences, Jawaharlal Nehru University, New Delhi 110 067 (India); Yadav, Arpana [Laboratory of Algal Biology, Department of Botany, Banaras Hindu University, Varanasi 221 005 (India); Gaur, J.P., E-mail: gaurjp@yahoo.co.in [Laboratory of Algal Biology, Department of Botany, Banaras Hindu University, Varanasi 221 005 (India)
2012-07-15
Prompted by the fact that interaction of metals with cyanobacterial mats has been little studied, the present study evaluates the response of a cyanobacterial mat, dominated by Phormidium bigranulatum, to elevated concentrations of Cd{sup 2+} in the medium. The mat failed to grow at 7 {mu}M of Cd{sup 2+} when the metal as also the mat inoculum were simultaneously added to the medium right in the beginning of the experiment due to marked sensitivity of P. bigranulatum, the main constituent of the mat, to high concentrations of Cd{sup 2+}. However, the mat previously grown in Cd{sup 2+}-free medium for a time period of 1-4 weeks grew successfully when exposed to media containing very high concentrations of Cd{sup 2+}. Four-week-old mat could grow at 250 {mu}M of Cd{sup 2+}, which has been found toxic to many cyanobacteria and algae by previous researchers. Greater tolerance of older mats to Cd{sup 2+} may be due to greater proportion of exopolysaccharides, which are well known to sequester metal ions extracellularly, in them. Whereas the relative proportion of P. bigranulatum declined at high concentrations of the test metal that of green algae increased due most likely to their tolerance to Cd{sup 2+}. Air bubbles were seen entrapped in the mat due obviously to photosynthetic activity. Elevated concentrations of Cd{sup 2+} reduced the number of air bubbles in the mat. Decline in number of air bubbles at high concentrations of metal ions was more prominent in the case of younger mat than in the older one. The present study also evaluated changes in species composition of mats of different age that were subsequently grown in Cd{sup 2+} enriched culture medium. Younger mats showed change in species composition at very low concentrations of Cd{sup 2+}, but older mats showed little changes even at very high concentrations of the test metal. Hence older mats more strongly resisted to changes in its species composition than the younger ones upon exposure to high
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Iniesto, Miguel; Buscalioni, Ángela D.; Carmen Guerrero, M.; Benzerara, Karim; Moreira, David; López-Archilla, Ana I.
2016-05-01
Microbial mats have been hypothesized to improve the persistence and the preservation of organic remains during fossilization processes. We test this hypothesis with long-term experiments (up to 5.5 years) using invertebrate and vertebrate corpses. Once placed on mats, the microbial community coats the corpses and forms a three-dimensional sarcophagus composed of microbial cells and exopolymeric substances (EPS). This coverage provides a template for i) moulding superficial features, resulting in negative impressions, and ii) generating replicas. The impressions of fly setulae, fish scales and frog skin verrucae are shaped mainly by small cells in an EPS matrix. Microbes also replicate delicate structures such as the three successive layers that compose a fish eye. The sarcophagus protects the body integrity, allowing the persistence of inner organs such as the ovaries and digestive apparatus in flies, the swim bladder and muscles in fish, and the bone marrow in frog legs. This study brings strong experimental evidence to the idea that mats favour metazoan fossilization by moulding, replicating and delaying decay. Rapid burial has classically been invoked as a mechanism to explain exceptional preservation. However, mats may play a similar role during early fossilization as they can preserve complex features for a long time.
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Electrospun chitosan-based nanocomposite mats reinforced with chitin nanocrystals for wound dressing
CSIR Research Space (South Africa)
Naseria, N
2014-08-01
Full Text Available The aim of this study was to develop electrospun chitosan/polyethylene oxide-based randomly oriented fiber mats reinforced with chitin nanocrystals (ChNC) for wound dressing. Microscopy studies showedporous mats of smooth and beadless fibers...
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Microbial Mats on the Orkney Islands Revisited: Microenvironment and Microbial Community Composition
DEFF Research Database (Denmark)
Wieland, A.; Kühl, M.; McGowan, L.
2003-01-01
of these sediments. High amounts of algal lipids and slightly higher numbers (genera, abundances) of cyanobacteria were found in Waulkmill Bay mats. However, overall only a few genera and low numbers of unicellular and filamentous cyanobacteria were present in mats from Waulkmill and Swanbister beach, as deduced...... fragment length polymorphism) analysis in Swanbister beach mats, the depth distribution of different populations of purple and sulfate-reducing bacteria could be related to the microenvironmental conditions. Oxygen, but also sulfide and other (inorganic and organic) sulfur compounds, seems to play...
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Counter-attack on viral hepatitis. [Hepatitis A; Hepatitis B
Energy Technology Data Exchange (ETDEWEB)
Prozesky, O W [Pretoria Univ. (South Africa). Dept. of Medical Virology; Jupp, P G; Joubert, J J; Taylor, M B; Grabow, W O.K.
1985-07-01
The most highly developed radioimmunoassay test system in medical virology is proving of exceptional value in research aimed at controlling and eventually eradicating the scourge of human hepatitis. The use of radioimmunoassay in detecting hepatitis A (HAV) and hepatitis B (HBV) viruses is discussed. The hepatitis A virus is an enterovirus which infects the gastrointestinal tract and is usually transmitted by contaminated food, milk or water. Hepatitis B spreads mainly by the parenteral rate. Bedbugs and ticks are considered as possible transmitters of HBV. Another important contribution of radioimmunoassay is the ability to monitor the immune response of persons at risk who are vaccinated against hepatitis B.
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Determination of 210Po in tea, mat and their infusions and its annual intake by Syrians
International Nuclear Information System (INIS)
Al-Masri, M.S.; Nashawati, A.; Amin, Y.; Al-Akel, B.
2004-01-01
Polonium-210 was determined in 34 kinds of imported tea and 9 kinds of mat collected from the Syrian local market. The 210 Po concentration was found to vary from 5.5 to 39 Bq x kg -1 and 47 to 82 Bq x kg -1 in tea and mat samples, respectively. In addition 210 Po was also determined in tea and mat infusions where different infusion conditions have been examined: amount, temperature and infusion time. The results have shown that the amount of 210 Po transferred from tea and mat leaves to the aqueous extract ranged from 9 to 21% and 3 to 15%, respectively. The annual intake of 210 Po by Syrians due to tea consumption and mat infusions was calculated and found to be 9 Bq and 151 Bq for tea and mat respectively: washing of mat with warm water is recommended before preparation the infusions to decrease the annual intake of 210 Po. (author)
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Three-dimensional visualization of forming Hepatitis C virus-like particles by electron-tomography
Energy Technology Data Exchange (ETDEWEB)
Badia-Martinez, Daniel; Peralta, Bibiana [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); Andres, German; Guerra, Milagros [Electron Microscopy Unit, Centro de Biologia Molecular Severo Ochoa, CSIC-UAM, Campus Cantoblanco, 28049 Madrid (Spain); Gil-Carton, David [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); Abrescia, Nicola G.A., E-mail: nabrescia@cicbiogune.es [Structural Biology Unit, CIC bioGUNE, CIBERehd, 48160 Derio (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain)
2012-09-01
Hepatitis C virus infects almost 170 million people per year but its assembly pathway, architecture and the structures of its envelope proteins are poorly understood. Using electron tomography of plastic-embedded sections of insect cells, we have visualized the morphogenesis of recombinant Hepatitis C virus-like particles. Our data provide a three-dimensional sketch of viral assembly at the endoplasmic reticulum showing different budding stages and contiguity of buds. This latter phenomenon could play an important role during the assembly of wt-HCV and explain the size-heterogeneity of its particles.
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Three-dimensional visualization of forming Hepatitis C virus-like particles by electron-tomography
International Nuclear Information System (INIS)
Badia-Martinez, Daniel; Peralta, Bibiana; Andrés, German; Guerra, Milagros; Gil-Carton, David; Abrescia, Nicola G.A.
2012-01-01
Hepatitis C virus infects almost 170 million people per year but its assembly pathway, architecture and the structures of its envelope proteins are poorly understood. Using electron tomography of plastic-embedded sections of insect cells, we have visualized the morphogenesis of recombinant Hepatitis C virus-like particles. Our data provide a three-dimensional sketch of viral assembly at the endoplasmic reticulum showing different budding stages and contiguity of buds. This latter phenomenon could play an important role during the assembly of wt-HCV and explain the size-heterogeneity of its particles.
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Kim, Hansang
2015-01-01
The in-plane shear property of carbon fiber laminates is one of the most important structural features of aerospace and marine structures. Fiber-matrix debonding caused by in-plane shear loading is the major failure mode of carbon fiber composites because of the stress concentration at the interfaces. In this study, carbon nanotube mats (CNT mat) were incorporated in two different types of carbon fiber composites. For the case of woven fabric composites, mechanical interlocking between the CNTs and the carbon fibers increased resistance to shear failure. However, not much improvement was observed for the prepreg composites as a result of incorporation of the CNT mats. The reinforcement mechanism of the CNT mat layer was investigated by a fractographic study using scanning electron microscopy. In addition, the CNT mat was functionalized by three different methods and the effectiveness of the functionalization methods was determined and the most appropriate functionalization method for the CNT mat was air oxidation.
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Russian Army Mat as a Code System Controlling Behaviour in the Russian army
Directory of Open Access Journals (Sweden)
Vadim Mikhailin
2004-09-01
Full Text Available This text is to be a shortened, restructured and based on somewhat another factological foundation version of my article “Russkii mat kak muzhskoi obstsennyi kod: problema proiskhozhdeniia i evoliutsiia statusa”, published in # 43 of Novoe Literaturnoe Obozrenie. Tracing the genesis of mat to the specific modes of behaviour, peculiar to the archaic male warrior bands, I’m going to show that the military milieu (and some other, structurally close to it social strata, has always been – and remain – absolutely adequate for the mat speaking. Moreover, mat has always carried on within these strata rather specific function connected with creating of one’s identity as a military, and its use offers various and sometimes the only possible means of impact at one’s equal or subordinate (or even superior. As a matter of fact, mat is a basis for a whole code system, controlling different military behaviour practices. The problems of the freshers’ adaptation and of the national specificities in the late Soviet and modern Russian army are to be considered with special respect.
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Directory of Open Access Journals (Sweden)
Yongfang Qian
2014-01-01
Full Text Available Design and fabrication of nanofibrous scaffolds should mimic the native extracellular matrix. This study is aimed at investigating electrospinning of polycaprolactone (PCL blended with chitosan-gelatin complex. The morphologies were observed from scanning electron microscope. As-spun blended mats had thinner fibers than pure PCL. X-ray diffraction was used to analyze the degree of crystallinity. The intensity at two peaks at 2θ of 21° and 23.5° gradually decreased with the percentage of chitosan-gelatin complex increasing. Moreover, incorporation of the complex could obviously improve the hydrophilicity of as-spun blended mats. Mechanical properties of as-spun nanofibrous mats were also tested. The elongation at break of fibrous mats increased with the PCL content increasing and the ultimate tensile strength varied with different weight ratios. The as-spun mats had higher tensile strength when the weight ratio of PCL to CS-Gel was 75/25 compared to pure PCL. Both as-spun PCL scaffolds and PCL/CS-Gel scaffolds supported the proliferation of porcine iliac endothelial cells, and PCL/CS-Gel had better cell viability than pure PCL. Therefore, electrospun PCL/Chitosan-gelatin nanofibrous mats with weight ratio of 75/25 have better hydrophilicity mechanical properties, and cell proliferation and thus would be a promising candidate for tissue engineering scaffolds.
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Munteanu, Daniel
2018-04-01
The main goal of the BraMat 2017 Conference was, as for the previous editions, to stimulate an international exchange of information in the field of materials science and engineering and to establish future research directions. The main topics of this edition included: Metallic materials (Section I), Biomaterials (Section II), Ceramics, polymers and composite materials (Section III), Surface engineering (Section IV), Nanomaterials (Section V), Welding engineering (Section VI), Safety engineering (Section VII), and Magnesium science and engineering (Section VIII).
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Directory of Open Access Journals (Sweden)
Jerome eBabauta
2014-01-01
Full Text Available Phototrophic microbial mats frequently exhibit sharp, light-dependent redox gradients that regulate microbial respiration on specific electron acceptors as a function of depth. In this work, a benthic phototrophic microbial mat from Hot Lake, a hypersaline, epsomitic lake located near Oroville in north-central Washington, was used to develop a microscale electrochemical method to study local electron transfer processes within the mat. To characterize the physicochemical variables influencing electron transfer, we initially quantified redox potential, pH and dissolved oxygen gradients by depth in the mat under photic and aphotic conditions. We further demonstrated that power output of a mat fuel cell was light-dependent. To study local electron transfer processes, we deployed a microscale electrode (microelectrode with tip size ~20 µm. To enrich a subset of microorganisms capable of interacting with the microelectrode, we anodically polarized the microelectrode in the mat. Subsequently, to characterize the microelectrode-associated community and compare it to the neighboring mat community, we performed amplicon sequencing of the V1-V3 region of the 16S gene. Differences in Bray-Curtis beta diversity, illustrated by large changes in relative abundance at the phylum level, suggested successful enrichment of specific mat community members on the microelectrode surface. The microelectrode-associated community exhibited substantially reduced alpha diversity and elevated relative abundances of Prosthecochloris, Loktanella, Catellibacterium, other unclassified members of Rhodobacteraceae, Thiomicrospira, and Limnobacter, compared with the community at an equivalent depth in the mat. Our results suggest that local electron transfer to an anodically polarized microelectrode selected for a specific microbial population, with substantially more abundance and diversity of sulfur-oxidizing phylotypes compared with the neighboring mat community.
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Babauta, Jerome T; Atci, Erhan; Ha, Phuc T; Lindemann, Stephen R; Ewing, Timothy; Call, Douglas R; Fredrickson, James K; Beyenal, Haluk
2014-01-01
Phototrophic microbial mats frequently exhibit sharp, light-dependent redox gradients that regulate microbial respiration on specific electron acceptors as a function of depth. In this work, a benthic phototrophic microbial mat from Hot Lake, a hypersaline, epsomitic lake located near Oroville in north-central Washington, was used to develop a microscale electrochemical method to study local electron transfer processes within the mat. To characterize the physicochemical variables influencing electron transfer, we initially quantified redox potential, pH, and dissolved oxygen gradients by depth in the mat under photic and aphotic conditions. We further demonstrated that power output of a mat fuel cell was light-dependent. To study local electron transfer processes, we deployed a microscale electrode (microelectrode) with tip size ~20 μm. To enrich a subset of microorganisms capable of interacting with the microelectrode, we anodically polarized the microelectrode at depth in the mat. Subsequently, to characterize the microelectrode-associated community and compare it to the neighboring mat community, we performed amplicon sequencing of the V1-V3 region of the 16S gene. Differences in Bray-Curtis beta diversity, illustrated by large changes in relative abundance at the phylum level, suggested successful enrichment of specific mat community members on the microelectrode surface. The microelectrode-associated community exhibited substantially reduced alpha diversity and elevated relative abundances of Prosthecochloris, Loktanella, Catellibacterium, other unclassified members of Rhodobacteraceae, Thiomicrospira, and Limnobacter, compared with the community at an equivalent depth in the mat. Our results suggest that local electron transfer to an anodically polarized microelectrode selected for a specific microbial population, with substantially more abundance and diversity of sulfur-oxidizing phylotypes compared with the neighboring mat community.
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Increasing Mechanical Properties of 2-D-Structured Electrospun Nylon 6 Non-Woven Fiber Mats
Directory of Open Access Journals (Sweden)
Chunhui Xiang
2016-04-01
Full Text Available Tensile strength, Young’s modulus, and toughness of electrospun nylon 6 non-woven fiber mats were improved by increasing individual nanofiber strength and fiber–fiber load sharing. Single-walled carbon nanotubes (CNTs were used as reinforcement to increase the strength of the electrospun nylon 6 nanofibers. Young’s modulus, tensile strength, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % solutions increased 51%, 87%, and 136%, respectively, after incorporating 1 wt % CNTs into the nylon 6 nanofibers. Three methods were investigated to enhance fiber–fiber load sharing: increasing friction between fibers, thermal bonding, and solvent bonding. The addition of beaded nylon 6 nanofibers into the non-woven fiber mats to increase fiber-fiber friction resulted in a statistically significantly increase in Young’s modulus over comparable smooth non-woven fiber mats. After annealing, tensile strength, elongation, and toughness of the nylon 6 non-woven fiber mats electrospun from 20 wt % + 10 wt % solutions increased 26%, 28%, and 68% compared to those from 20 wt % solutions. Solvent bonding with formic acid vapor at room temperature for 30 min caused increases of 56%, 67%, and 39% in the Young’s modulus, tensile strength, and toughness of non-woven fiber mats, respectively. The increases attributed to increased individual nanofiber strength and solvent bonding synergistically resulted in the improvement of Young’s modulus of the electrospun nylon 6 non-woven fiber mats.
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Phenotypic variation and characterization of mutant matting in shiitake
International Nuclear Information System (INIS)
Ibrahim Mahmood; Azhar Mohamad
2016-01-01
Shiitake (Lentinula edodes) is an edible mushroom that has many uses such as: pharmaceutical, nutraceutical and cosmeceutical industries. In this study, we will induce Shiitake to create the genetic variation via exposing the spores of shiitake to gamma (γ) ray at different doses (0-700 Gy) then make the matting between two different monokaryon mycelium (MM). potato dextrose agar (PDA), this media will be used for spore germination and monokaryon mycelium subculturing during this study. The compatibility of the matting will be observed macroscopically (observing on the plates of PDA) and microscopically (by observing the clamps test under the microscope (Olympus brand)). The finding of this study, there is no significant changing in the growth performance of irradiated monokaryon mycelium in comparing with non-irradiated mycelium. From 108 matting only 15 were compatibles. This study, the physical mutagen will be used followed by mating as a normal stage of life cycle for creating potential strain of shiitake with alteration in phenotypic characterization of dikaryon mycelium (DM) as a compatible mating for two MM. (author)
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Directory of Open Access Journals (Sweden)
Héctor Rubén Hernández Garcés
1998-10-01
Full Text Available Se realizó una revisión bibliográfica de las hepatitis virales agudas sobre aspectos vinculados a su etiología. Se tuvieron en cuenta además algunos datos epidemiológicos, las formas clínicas más importantes, los exámenes complementarios con especial énfasis en los marcadores virales y el diagnóstico positivoA bibliographical review of acute viral hepatitis was made taking into account those aspects connected with its etiology. Some epidemiological markers, the most important clinical forms, and the complementary examinations with special emphasis on the viral markers and the positive diagnosis were also considered
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Bolton, M.D.; Jonge, de R.; Inderbitzin, P.; Liu, Z.; Birla, K.; Peer, Van de Y.; Subbarao, K.; Thomma, B.P.H.J.; Secor, G.
2014-01-01
Dothideomycetes is one of the most ecologically diverse and economically important classes of fungi. Sexual reproduction in this group is governed by mating type (MAT) genes at the MAT1 locus. Self-sterile (heterothallic) species contain one of two genes at MAT1 (MAT1-1-1 or MAT1-2-1) and only
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Lee, C H; Chang, S C; Wu, C H; Chang, M F
2001-03-16
Hepatitis delta virus (HDV) is a satellite virus of hepatitis B virus, as it requires hepatitis B virus for virion production and transmission. We have previously demonstrated that sequences within the C-terminal 19-amino acid domain flanking the isoprenylation motif of the large hepatitis delta antigen (HDAg-L) are important for virion assembly. In this study, site-directed mutagenesis and immunofluorescence staining demonstrated that in the absence of hepatitis B virus surface antigen (HBsAg), the wild-type HDAg-L was localized in the nuclei of transfected COS7 cells. Nevertheless, in the presence of HBsAg, the HDAg-L became both nuclei- and cytoplasm-distributed in about half of the cells. An HDAg-L mutant with a substitution of Pro-205 to alanine could neither form HDV-like particles nor shift the subcellular localization in the presence of HBsAg. In addition, nuclear trafficking of HDAg-L in heterokaryons indicated that HDAg-L is a nucleocytoplasmic shuttling protein. A proline-rich HDAg peptide spanning amino acid residues 198 to 210, designated NES(HDAg-L), can function as a nuclear export signal (NES) in Xenopus oocytes. Pro-205 is critical for the NES function. Furthermore, assembly of HDV is insensitive to leptomycin B, indicating that the NES(HDAg-L) directs nuclear export of HDAg-L to the cytoplasm via a chromosome region maintenance 1-independent pathway.
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Directory of Open Access Journals (Sweden)
Elsayed A. Elbadry
2012-01-01
Full Text Available Recycled needle punched jute fiber mats as a first natural fiber reinforcement system and these jute mats used as a core needle punched with recycled jute fabric cloths as skin layers as a second natural fiber reinforcement system were used for unsaturated polyester matrix composites via modifying the hand lay-up technique with resin preimpregnation into the jute fiber in vacuum. The effect of skin jute fabric on the tensile and bending properties of jute mat composites was investigated for different fiber weight contents. Moreover, the notch sensitivity of these composites was also compared by using the characteristic distance do calculated by Finite Element Method (FEM. The results showed that the tensile and flexural properties of jute mat composites increased by increasing the fiber weight content and by adding the jute fabric as skin layers. On the other hand, by adding the skins, the characteristic distance decreased and, therefore, the notch sensitivity of the composites increased. The fracture behavior investigated by SEM showed that extensive fiber pull-out mechanism was revealed at the tension side of jute mat composites under the bending load and by adding the jute cloth, the failure mode of jute mat was changed to fiber bridge mechanism.
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Electron microscopy study of microbial mat in the North Fiji basin hydrothermal vent
Park, H.; Kim, J. W.; Lee, J. W.
2017-12-01
Hydrothermal vent systems consisting of hydrothermal vent, hydrothermal sediment and microbial mat are widely spread around the ocean, particularly spreading axis, continental margin and back-arc basin. Scientists have perceived that the hydrothermal systems, which reflect the primeval earth environment, are one of the best places to reveal the origin of life and extensive biogeochemical process of microbe-mineral interaction. In the present study multiline of analytical methods (X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM)) were utilized to investigate the mineralogy/chemistry of microbe-mineral interaction in hydrothermal microbial mat. Microbial mat samples were recovered by Canadian scientific submersible ROPOS on South Pacific North Fiji basin KIOST hydrothermal vent expedition 1602. XRD analysis showed that red-colored microbial mat contains Fe-oxides and Fe-oxyhydroxides. Various morphologies of minerals in the red-colored microbial mat observed by SEM are mainly showed sheath shaped, resembled with Leptothrix microbial structure, stalks shaped, similar with Marioprofundus microbial structure and globule shaped microbial structures. They are also detected with DNA analysis. The cross sectional observation of microbial structures encrusted with Fe-oxide and Fe-oxyhydroxide at a nano scale by Transmission Electron Microscopy (TEM) and Focused Ion Beam (FIB) technique was developed to verify the structural/biogeochemical properties in the microbe-mineral interaction. Systematic nano-scale measurements on the biomineralization in the microbial mat leads the understandings of biogeochemical environments around the hydrothermal vent.
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Ip, Blanche C; Liu, Chun; Lichtenstein, Alice H; von Lintig, Johannes; Wang, Xiang-Dong
2015-01-01
Background: Nonalcoholic fatty liver disease is positively associated with obesity and cardiovascular disease risk. Apo-10′-lycopenoic acid (APO10LA), a potential oxidation product of apo-10′-lycopenal that is generated endogenously by β-carotene-9′,10′-oxygenase (BCO2) cleavage of lycopene, inhibited hepatic steatosis in BCO2-expressing mice. Objective: The present study evaluated lycopene and APO10LA effects on hepatic steatosis in mice without BCO2 expression. Methods: Male and female BCO2-knockout (BCO2-KO) mice were fed a high saturated fat diet (HSFD) with or without APO10LA (10 mg/kg diet) or lycopene (100 mg/kg diet) for 12 wk. Results: Lycopene or APO10LA supplementation reduced hepatic steatosis incidence (78% and 72%, respectively) and severity in BCO2-KO male mice. Female mice did not develop steatosis, had greater hepatic total cholesterol (3.06 vs. 2.31 mg/g tissue) and cholesteryl ester (1.58 vs. 0.86 mg/g tissue), but had lower plasma triglyceride (TG) (229 vs. 282 mg/dL) and cholesterol (97.1 vs. 119 mg/dL) than male mice. APO10LA-mitigated steatosis in males was associated with reduced hepatic total cholesterol (18%) and activated sirtuin 1 signaling, which resulted in reduced fatty acids (FAs) and TG synthesis markers [stearoyl-coenzyme A (CoA) desaturase protein, 71%; acetyl-CoA carboxylase phosphorylation, 79%; AMP-activated protein kinase phosphorylation, 67%], and elevated cholesterol efflux genes (cytochrome P450 family 7A1, 65%; ATP-binding cassette transporter G5/8, 11%). These APO10LA-mediated effects were not mimicked by lycopene supplementation. Intriguingly, steatosis inhibition by lycopene induced peroxisome proliferator–activated receptor (PPAR)α- and PPARγ-related genes in mesenteric adipose tissue (MAT) that increases mitochondrial uncoupling [cell death–inducing DNA fragmentation factor, α subunit-like effector a, 55%; PR domain-containing 16, 47%; uncoupling protein 3 (Ucp3), 55%], FA β-oxidation (PPARα, 53
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The ichthyofauna of drifting macrophyte mats in the Ivinhema River, upper Paraná River basin, Brazil
Bulla, C. K.; Gomes, Luiz Carlos; Miranda, Leandro E.; Agostinho, A. A.
2011-01-01
We describe the fish assemblages associated with drifting macrophyte mats and consider their possible role as dispersal vectors in the Ivinhema River, a major tributary of the upper Paraná River, Brazil. Fish associated with drifting mats were sampled in the main river channel during January and March 2005, when the wind and/or the increased water level were sufficient to transport macrophyte stands. Fish in the drifting mats were sampled with a floating sieve (4 m long x 2 m wide x 0.6 m high, and 2 mm mesh size). In the laboratory, larvae, juvenile, and adult fish were counted and identified to the lowest possible taxonomic level. In four drifting macrophyte mats we captured 218 individuals belonging to at least 28 species, 17 families, and 6 orders. Aphyocharax dentatus, Serrasalmus spp., and Trachelyopterus galeatus were the most abundant taxa associated with the mats, but species richness ranged from 6 to 24 species per mat. In addition, 85% of the total number of individuals caught was larvae and juveniles. Although preliminary and based on limited samples, this study of drifting macrophyte mats was the first one in the last unregulated stretch of the Paraná River remaining inside Brazilian territory, and alerts us to the potential role of macrophytes mats as dispersers of fish species in the region.
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Vulnerability of R-MAT networks with communities
Directory of Open Access Journals (Sweden)
Nikolay Alexandrovich Kinash
2016-06-01
Full Text Available A generator R-MAT for modeling networks with different laws of link constructions within and between communities has been developed. Network attack simulations have been performed and pertinent robustness of diverse network combinations has been concluded.
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Pathogenesis and Prevention of Hepatic Steatosis
Nassir, Fatiha; Rector, R. Scott; Hammoud, Ghassan M.
2015-01-01
Hepatic steatosis is defined as intrahepatic fat of at least 5% of liver weight. Simple accumulation of triacylglycerols in the liver could be hepatoprotective; however, prolonged hepatic lipid storage may lead to liver metabolic dysfunction, inflammation, and advanced forms of nonalcoholic fatty liver disease. Nonalcoholic hepatic steatosis is associated with obesity, type 2 diabetes, and dyslipidemia. Several mechanisms are involved in the accumulation of intrahepatic fat, including increased flux of fatty acids to the liver, increased de novo lipogenesis, and/or reduced clearance through β-oxidation or very-low-density lipoprotein secretion. This article summarizes the mechanisms involved in the accumulation of triacylglycerols in the liver, the clinical implications, and the prevention of hepatic steatosis, with a focus on the role of mitochondrial function and lifestyle modifications. PMID:27099587
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Anti-fatigue mats, low back pain, and electromyography: An interventional study.
Aghazadeh, Javad; Ghaderi, Mahmoud; Azghani, Mahmood-Reza; Khalkhali, Hamid-Reza; Allahyari, Teimour; Mohebbi, Iraj
2015-01-01
Increasing bilateral gluteus medius co-activation has been identified as one of the most important factors in developing low back pain due to prolonged standing in healthy people. This study aims to investigate the impact of an anti-fatigue mat on the bilateral gluteus medius co-activation pattern and to report the low back pain subjectively in 2 different standing positions on the normal rigid surface and on the anti-fatigue mat. While carrying out an easy simulated profession, 16 participants who had no low back pain background were requested to stand for 2 h in each position, with and without using the anti-fatigue floor mat, respectively. At the beginning of standing process and at every 15 min until the time of 120 min lapses, electric activities for the bilateral gluteus medius co-activation and subjective pain level in low back area were collected by the surface electromyogeraphy (EMG) and the visual analogue scale (VAS), respectively in each position. The obtained findings revealed that the anti-fatigue mat significantly decreased subjective pain level in low back area among 15 participants (p 0.05). The findings obtained under this study related to the impact of the anti-fatigue mat upon the low back pain based on the increase of > 10 mm on the VAS threshold, which showed that this intervention had no significant impact upon decreasing the number of patients suffering from the low back pain and also minimizing the bilateral gluteus medius co-activation in both pain developer groups (p > 0.05). However, 73% of the participants preferred to apply it. It seems that the anti-fatigue mat may be useful in reducing the low back pain although it objectively didn't significantly change the gluteus medius co-activation pattern related to the low back pain. This work is available in Open Access model and licensed under a CC BY-NC 3.0 PL license.
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Gong, J.; Edwardson, C.; Mackey, T. J.; Dzaugis, M.; Ibarra, Y.; Course 2012, G.; Frantz, C. M.; Osburn, M. R.; Hirst, M.; Williamson, C.; Hanselmann, K.; Caporaso, J.; Sessions, A. L.; Spear, J. R.
2012-12-01
The microbial diversity of Stinking Springs, a sulfidic, saline, warm spring northeast of the Great Salt Lake was investigated. The measured pH, temperature, salinity, and sulfide concentration along the flow path ranged from 6.64-7.77, 40-28° C, 2.9-2.2%, and 250 μM to negligible, respectively. Five sites were selected along the flow path and within each site microbial mats were dissected into depth profiles based on the color and texture of the mat layers. Genomic DNA was extracted from each layer, and the 16S rRNA gene was amplified and sequenced on the Roche 454 Titanium platform. Fatty acids were also extracted from the mat layers and analyzed by liquid chromatography and mass spectrometry. The mats at Stinking Springs were classified into roughly two morphologies with respect to their spatial distribution: loose, sometimes floating mats proximal to the spring source; and thicker, well-laminated mats distal to the spring source. Loosely-laminated mats were found in turbulent stream flow environments, whereas well-laminated mats were common in less turbulent sheet flows. Phototrophs, sulfur oxidizers, sulfate reducers, methanogens, other bacteria and archaea were identified by 16S rRNA gene sequences. Diatoms, identified by microscopy and lipid analysis were found to increase in abundance with distance from the source. Methanogens were generally more abundant in deeper mat laminae. Photoheterotrophs were found in all mat layers. Microbial diversity increased significantly with depth at most sites. In addition, two distinct microbial streamers were identified and characterized at the two fast flowing sites. These two streamer varieties were dominated by either cyanobacteria or flavobacteria. Overall, our genomic and lipid analysis suggest that the physical and chemical environment is more predictive of the community composition than mat morphology. Site Map
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Jonkers, Henk M; Ludwig, Rebecca; Wit, Rutger; Pringault, Olivier; Muyzer, Gerard; Niemann, Helge; Finke, Niko; Beer, Dirk
2003-05-01
The benthic microbial mat community of the only permanent hypersaline natural inland lake of Western Europe, 'La Salada de Chiprana', northeastern Spain, was structurally and functionally analyzed. The ionic composition of the lake water is characterized by high concentrations of magnesium and sulfate, which were respectively 0.35 and 0.5 M at the time of sampling while the total salinity was 78 g l(-1). Community composition was analyzed by microscopy, high-performance liquid chromatography (HPLC) pigment analyses and by studying culturable bacteria from different functional groups. Therefore, denaturing gradient gel electrophoresis (DGGE) was applied on most probable number (MPN) dilution cultures. Microscopy revealed that a thin layer of Chloroflexus-like bacteria overlaid various cyanobacteria-dominated layers each characterized by different morphotypes. DGGE analysis of MPN dilution cultures from distinct mat layers showed that various phylotypes of anoxygenic phototrophic, aerobic heterotrophic, colorless sulfur-, and sulfate-reducing bacteria were present. The mats were furthermore functionally studied and attention was focussed on the relationship between oxygenic primary production and the flow of carbon through the microbial community. Microsensor techniques, porewater and sediment photopigment analysis were applied in order to estimate oxygenic photosynthetic rates, daily dynamics of (in)organic carbon porewater concentration and migration behavior of phototrophs. Chiprana microbial mats produced dissolved organic carbon (DOC) both during the day and night. It was estimated that 14% of the mats gross photosynthetic production and 49% of the mats net photosynthetic production diffused out of the mat in the form of low molecular mass fatty acids, although these compounds made up only 2% of the total DOC pool. The high flux of dissolved fatty acids from the microbial mat to the water column may explain why in this system Chloroflexus-like bacteria
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Full Text Available ... Disease Type 1 (von Gierke) Hemochromatosis Hepatic Encephalopathy Hepatitis A Hepatitis B Hepatitis C Intrahepatic Cholestasis of Pregnancy ( ... Disease Type 1 (von Gierke) Hemochromatosis Hepatic Encephalopathy Hepatitis A Hepatitis B Hepatitis C Intrahepatic Cholestasis of Pregnancy ( ...
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Groundwater mixing at fracture intersections triggers massive iron-rich microbial mats
Bochet, O.; Le Borgne, T.; Bethencourt, L.; Aquilina, L.; Dufresne, A.; Pédrot, M.; Farasin, J.; Abbott, B. W.; Labasque, T.; Chatton, E.; Lavenant, N.; Petton, C.
2017-12-01
While most freshwater on Earth resides and flows in groundwater systems, these deep subsurface environments are often assumed to have little biogeochemical activity compared to surface environments. Here we report a massive microbial mat of iron-oxidizing bacteria, flourishing 60 meters below the surface, far below the mixing zone where most microbial activity is believed to occur. The abundance of microtubular structures in the mat hinted at the prevalence of of Leptothrix ochracea, but metagenomic analysis revealed a diverse consortium of iron-oxidizing bacteria dominated by unknown members of the Gallionellaceae family. This deep biogeochemical hot spot formed at the intersection of bedrock fractures, which maintain redox gradients by mixing water with different residence times and chemical compositions. Using measured fracture properties and hydrological conditions we developed a quantitative model to simulate the reactive zone where such deep hot spots could occur. While seasonal fluctuations are generally thought to decrease with depth, we found that meter-scale changes in water table level moved the depth of the reactive zone hundreds of meters because the microaerophilic threshold for ironoxidizers is highly sensitive to changes in mixing rates at fracture intersections. These results demonstrate that dynamic microbial communities can be sustained deep below the surface in bedrock fractures. Given the ubiquity of fractures at multiple scales in Earth's subsurface, such deep hot spots may strongly influence global biogeochemical cycles.
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Energy Technology Data Exchange (ETDEWEB)
Zhao, Cunzhen; Chen, Xiaochang; Wu, Wenjing; Wang, Wusu; Pang, Weijun; Yang, Gongshe, E-mail: gsyang999@hotmail.com
2016-05-15
Intramuscular fat (IMF) has been demonstrated as one of the crucial factors of livestock meat quality. The MAT2B protein with MAT2α catalyzes the formation of methyl donor S- adenosylmethionine (SAMe) to mediate cell metabolism including proliferation and apoptosis. However, the regulatory effect of MAT2B on IMF deposition is still unclear. In this study, the effect of MAT2B on adipogenesis and its potential mechanism during porcine intramuscular preadipocyte differentiation was studied. The results showed that overexpression of MAT2B promoted adipogenesis and significantly up-regulated the mRNA and protein levels of adipogenic marker genes including FASN, PPARγ and aP2, consistently, knockdown of MAT2B inhibited lipid accumulation and down-regulated the mRNA and protein levels of the above genes. Furthermore, flow cytometry and EdU-labeling assay indicated that MAT2B regulate adipogenesis was partly due to influence intracellular SAMe levels and further affect cell clonal expansion. Also, increased expression of MAT2B activated the phosphorylations of AKT and ERK1/2, whereas knockdown of MAT2B blocked AKT signaling and repressed the phosphorylation of ERK1/2. Moreover, the inhibitory effect of LY294002 (a specific PI3K inhibitor) on the activities of AKT and ERK1/2 was partially recovered by overexpression of MAT2B in porcine intramuscular adipocytes. Finally, Co-IP experiments showed that MAT2B can directly interact with AKT. Taken together, our findings suggested that MAT2B acted as a positive regulator through modifying SAMe levels as well as activating AKT/ERK signaling pathway to promote porcine intramuscular adipocyte differentiation. - Highlights: • MAT2B up-regulates the expression of adipogenic marker genes and promotes porcine intramuscular preadipocyte differentiation. • MAT2B influences intracellular SAMe levels and further affects cell clonal expansion. • MAT2B interacts with AKT and activates AKT/ERK signaling pathway.
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Bhaskar, V. Vijaya; Srinivas, Kolla
2017-07-01
Polymer reinforced composites have been replacing most of the engineering material and their applications become more and more day by day. Polymer composites have been analyzing from past thirty five years for their betterment for adapting more applications. This paper aims at the mechanical properties of polyester reinforced with glass fiber composites. The glass fiber is reinforced with polyester in two forms viz Woven Rovings (WRG) and Chopped Strand Mat (CSMG) E-glass fibers. The composites are fabricated by hand lay-up technique and the composites are cut as per ASTM Standard sizes for corresponding tests like flexural, compression and impact tests, so that flexural strength, compression strength, impact strength and inter laminar shear stress(ILSS) of polymer matrix composites are analyzed. From the tests and further calculations, the polyester composites reinforced with Chopped Strand Mat glass fiber have shown better performance against flexural load, compression load and impact load than that of Woven Roving glass fiber.
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Keszthelyi, A.; Jeney, A.; Kerenyi, Z.; Mendes, O.; Waalwijk, C.; Hornok, L.
2007-01-01
Mating type in filamentous ascomycetes is controlled by idiomorphic alleles, named MAT1-1 and MAT1-2, which contain 1-3 genes. Of these genes MAT1-1-1 and MAT1-2-1 encode putative transcription factors and are thus considered to be the major regulators of sexual communication and mating. Fungi with
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Modeling the pullout characteristics of welded wire mats embedded in silty sand
International Nuclear Information System (INIS)
Sampaco, C.L.; Anderson, L.R.; Nielson, M.R.
1994-01-01
This paper is an outgrowth of the on-going research on discrete finite element modeling of welded wire mesh reinforced soil structures such as the welded wire and RSE walls. The stiffness characteristics of the wire mesh-soil interfaces are modeled by a nonlinear hyperbolic relationship between the applied pullout stress and the associated mat placement. The relevant parameters are estimated from laboratory pullout tests that were conducted for welded wire mats embedded on silty sand. Since the bulk of the pullout resistance of welded wire mesh reinforcements is derived from the bearing resistance of the transverse wires that constitute the test mats. This feature permits proper evaluation of actual interface parameters for the actual reinforced soil structures in which the actual lengths of the mats are longer (i.e. more transverse members) than the specimen used in the laboratory pullout tests. The resulting pullout stress-displacement formulations are then verified by comparing the predicted pullout resistance to the existing specifications and design methods for estimated the pullout capacities of grid reinforcements. 22 refs., 13 figs
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Chapitre 4. Matériaux de construction et de décoration
Harlé-Sambet, Yvonne; Cabart, Hubert; Charmoillaux, Julie; Girard, Ghislaine
2017-01-01
Si la brique apparaît comme le matériau le plus utilisé lors de la construction du château, on est cependant frappé par la variété des autres matériaux mis en œuvre. Les murs les plus anciens du logis est (XIIe siècle) ainsi que les fondations et le soubassement du château de brique (fin XIIIe siècle) sont constitués de maçonneries de galets liés au mortier. Le galet est en effet le matériau le plus fréquemment utilisé à toutes les époques dans les constructions du bas-Dauphiné. Cependant à B...
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MatMCNP: A Code for Producing Material Cards for MCNP
Energy Technology Data Exchange (ETDEWEB)
DePriest, Kendall Russell [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Saavedra, Karen C. [American Structurepoint, Inc., Indianapolis, IN (United States)
2014-09-01
A code for generating MCNP material cards (MatMCNP) has been written and verified for naturally occurring, stable isotopes. The program allows for material specification as either atomic or weight percent (fractions). MatMCNP also permits the specification of enriched lithium, boron, and/or uranium. In addition to producing the material cards for MCNP, the code calculates the atomic (or number) density in atoms/barn-cm as well as the multiplier that should be used to convert neutron and gamma fluences into dose in the material specified.
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Accuracy of Jump-Mat Systems for Measuring Jump Height.
Pueo, Basilio; Lipinska, Patrycja; Jiménez-Olmedo, José M; Zmijewski, Piotr; Hopkins, Will G
2017-08-01
Vertical-jump tests are commonly used to evaluate lower-limb power of athletes and nonathletes. Several types of equipment are available for this purpose. To compare the error of measurement of 2 jump-mat systems (Chronojump-Boscosystem and Globus Ergo Tester) with that of a motion-capture system as a criterion and to determine the modifying effect of foot length on jump height. Thirty-one young adult men alternated 4 countermovement jumps with 4 squat jumps. Mean jump height and standard deviations representing technical error of measurement arising from each device and variability arising from the subjects themselves were estimated with a novel mixed model and evaluated via standardization and magnitude-based inference. The jump-mat systems produced nearly identical measures of jump height (differences in means and in technical errors of measurement ≤1 mm). Countermovement and squat-jump height were both 13.6 cm higher with motion capture (90% confidence limits ±0.3 cm), but this very large difference was reduced to small unclear differences when adjusted to a foot length of zero. Variability in countermovement and squat-jump height arising from the subjects was small (1.1 and 1.5 cm, respectively, 90% confidence limits ±0.3 cm); technical error of motion capture was similar in magnitude (1.7 and 1.6 cm, ±0.3 and ±0.4 cm), and that of the jump mats was similar or smaller (1.2 and 0.3 cm, ±0.5 and ±0.9 cm). The jump-mat systems provide trustworthy measurements for monitoring changes in jump height. Foot length can explain the substantially higher jump height observed with motion capture.
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Mekh-mat entrance examinations problems
Vardi, I
2000-01-01
This paper provides a complete solution set to 25 ``killer problems'' given to Jewish candidates to the Mekh--mat at Moscow State University during the 1970's and 1980's. Typically, the problems are at the mathematical olympiad level and some feature interesting theorems. However, a number of the problems are flawed, or even completely wrong. The paper therefore includes an evaluation of the problems in the style of a referee report.
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Full-Scale Evaluation of DuraDeck (registered trademark) and MegaDeck (trademark) Matting Systems
2013-07-01
plates studded with threaded bolts were placed ERDC/GSL TR-13-27 10 underneath two pre-drilled corners of the panel. The plates were positioned so...metal plates studded with threaded ERDC/GSL TR-13-27 4 Figure 1. DuraDeck® mat panel, top surface. Figure 2. DuraDeck® mat panel, bottom surface...ERDC/GSL TR-13-27 5 bolts , as shown in Figure 3, underneath the mat corners and then installing special connector nuts from the top surface
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Simulated Carbon Cycling in a Model Microbial Mat.
Decker, K. L.; Potter, C. S.
2006-12-01
We present here the novel addition of detailed organic carbon cycling to our model of a hypersaline microbial mat ecosystem. This ecosystem model, MBGC (Microbial BioGeoChemistry), simulates carbon fixation through oxygenic and anoxygenic photosynthesis, and the release of C and electrons for microbial heterotrophs via cyanobacterial exudates and also via a pool of dead cells. Previously in MBGC, the organic portion of the carbon cycle was simplified into a black-box rate of accumulation of simple and complex organic compounds based on photosynthesis and mortality rates. We will discuss the novel inclusion of fermentation as a source of carbon and electrons for use in methanogenesis and sulfate reduction, and the influence of photorespiration on labile carbon exudation rates in cyanobacteria. We will also discuss the modeling of decomposition of dead cells and the ultimate release of inorganic carbon. The detailed modeling of organic carbon cycling is important to the accurate representation of inorganic carbon flux through the mat, as well as to accurate representation of growth models of the heterotrophs under different environmental conditions. Because the model ecosystem is an analog of ancient microbial mats that had huge impacts on the atmosphere of early earth, this MBGC can be useful as a biological component to either early earth models or models of other planets that potentially harbor life.
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... Workshops Follow Us Home Health Information Liver Disease Hepatitis (Viral) Hepatitis C Related Topics English English Español Section Navigation Hepatitis (Viral) What Is Viral Hepatitis? Hepatitis A Hepatitis B ...
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Energy Technology Data Exchange (ETDEWEB)
Yousefi, Iman, E-mail: iman_yousefi@ut.ac.ir [School of Chemical Engineering, College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of); Medical Biomaterials Research Center (MBRC), Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Pakravan, Mehdi [Department of Chemical Engineering, Ecole Polytechnique de Montreal, Montreal, Quebec (Canada); Rahimi, Hoda [Department of Pharmacognosy, School of Pharmacy, Shahid Beheshti University of Medical Sciences, Tehran (Iran, Islamic Republic of); Bahador, Abbas; Farshadzadeh, Zahra [Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Haririan, Ismael, E-mail: haririan@tums.ac.ir [Medical Biomaterials Research Center (MBRC), Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Pharmaceutical Biomaterial, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of); Department of Pharmaceutics, School of Pharmacy, Tehran University of Medical Sciences, Tehran (Iran, Islamic Republic of)
2017-06-01
Wound healing characteristics of some plant extracts have been well known for many years, and they have been utilized for such applications in traditional way. Recently electrospun nanofibrous mats showed promising properties for tissue engineering and especially for skin repair. It is expected that incorporation of plant extracts into such structures could provide higher performance and synergistic effect for biomedical and wound healing applications. The final purpose of this study is to fabricate chitosan based nanofiber mats loaded with a traditional plant extract of Lawsonia inermis (Henna) leaves to enhance the antibacterial efficacy and wound healing of the precursor nanofibers. The morphology, structure, mechanical properties and swelling and weight loss degree of the electrospun nanofibers have been investigated in this study. Antibacterial activity, cell biocompatibility evaluations and in vivo wound healing activity of the abovementioned mats were also studied. The FESEM images of Henna leaves extract-loaded nanofibers proved that homogeneous, smooth and defect free nanofibers of 64–87 nm in diameter have been prepared. Presence of Henna extract in the electrospun fibers was approved by Fourier Transform Infrared spectroscopy. Incorporation of Henna extract into the nanofiber mats exhibited significant synergistic antibacterial activity against bacterial cells. It was well supported by the results of cell viability and proliferation of human foreskin fibroblast cells on the prepared scaffolds. Therefore, the results of this work showed that Henna leaves extract incorporated chitosan nonwoven mats have a great potential to be used as the biodegradable, biobased and antibacterial wound healing dressings. - Highlights: • Henna leaves extract were successfully loaded into chitosan based nanofiber mats. • These mats demonstrated significant synergistic antibacterial activity. • Combined properties of chitosan nanofibers and Henna promoted cell
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International Nuclear Information System (INIS)
Yousefi, Iman; Pakravan, Mehdi; Rahimi, Hoda; Bahador, Abbas; Farshadzadeh, Zahra; Haririan, Ismael
2017-01-01
Wound healing characteristics of some plant extracts have been well known for many years, and they have been utilized for such applications in traditional way. Recently electrospun nanofibrous mats showed promising properties for tissue engineering and especially for skin repair. It is expected that incorporation of plant extracts into such structures could provide higher performance and synergistic effect for biomedical and wound healing applications. The final purpose of this study is to fabricate chitosan based nanofiber mats loaded with a traditional plant extract of Lawsonia inermis (Henna) leaves to enhance the antibacterial efficacy and wound healing of the precursor nanofibers. The morphology, structure, mechanical properties and swelling and weight loss degree of the electrospun nanofibers have been investigated in this study. Antibacterial activity, cell biocompatibility evaluations and in vivo wound healing activity of the abovementioned mats were also studied. The FESEM images of Henna leaves extract-loaded nanofibers proved that homogeneous, smooth and defect free nanofibers of 64–87 nm in diameter have been prepared. Presence of Henna extract in the electrospun fibers was approved by Fourier Transform Infrared spectroscopy. Incorporation of Henna extract into the nanofiber mats exhibited significant synergistic antibacterial activity against bacterial cells. It was well supported by the results of cell viability and proliferation of human foreskin fibroblast cells on the prepared scaffolds. Therefore, the results of this work showed that Henna leaves extract incorporated chitosan nonwoven mats have a great potential to be used as the biodegradable, biobased and antibacterial wound healing dressings. - Highlights: • Henna leaves extract were successfully loaded into chitosan based nanofiber mats. • These mats demonstrated significant synergistic antibacterial activity. • Combined properties of chitosan nanofibers and Henna promoted cell
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Energy Technology Data Exchange (ETDEWEB)
Wu, Keke; Zhang, Xiazhi; Yang, Wufeng; Liu, Xiaoyan; Jiao, Yanpeng, E-mail: tjiaoyp@jnu.edu.cn; Zhou, Changren
2016-12-30
Highlights: • Layer-by-layer assembled PLLA nanofiber mats were successfully prepared. • The modified PLLA nanofiber mats enhanced the adhesion, proliferation of endothelial cells. • The modified PLLA nanofiber mats had inhibited the inflammatory response to some extent. - Abstract: Electrospun poly(L-lactic acid) (PLLA) nanofiber mats were successfully modified by deposition of multilayers with chitosan (CS), heparin (Hep) and graphene oxide (GO) through electrostatic layer-by-layer (LBL) self-assembly method. In this study, the surface properties of PLLA nanofiber mats before and after modification were investigated via scanning electron microscope (SEM), atomic force microscopy (AFM), attenuated total reflectance fourier transformation infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and water contact angle measurement. In addition, the cytocompatibility of the modified PLLA nanofiber mats were investigated by testing endothelial cells compatibility, including cell attachment, cell proliferation and cell cycle. The results revealed that the surfaces of modified PLLA nanofiber mats become much rougher, stifiness and the hydrophilicity of the LBL modified PLLA nanofiber mats were improved compared to original PLLA one. Moreover, the modified PLLA nanofiber mats had promoted the endothelial cells viability attachment significantly. Besides, we studied the PLLA nanofiber mats on the expression of necrosis factor (TNF-α), interleukine-1β (IL-1β), monocyte chemoattractant protein-1 (MCP-1) and vascular cell adhesion molecule-1 (VCAM-1) in endothelial cells. The results showed that modified PLLA nanofiber mats had inhibited the inflammatory response to some extent.
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Halloysite nanotube-based electrospun ceramic nanofibre mat: a novel support for zeolite membranes
Chen, Zhuwen; Zeng, Jiaying; Lv, Dong; Gao, Jinqiang; Zhang, Jian; Bai, Shan; Li, Ruili; Hong, Mei; Wu, Jingshen
2016-12-01
Some key parameters of supports such as porosity, pore shape and size are of great importance for fabrication and performance of zeolite membranes. In this study, we fabricated millimetre-thick, self-standing electrospun ceramic nanofibre mats and employed them as a novel support for zeolite membranes. The nanofibre mats were prepared by electrospinning a halloysite nanotubes/polyvinyl pyrrolidone composite followed by a programmed sintering process. The interwoven nanofibre mats possess up to 80% porosity, narrow pore size distribution, low pore tortuosity and highly interconnected pore structure. Compared with the commercial α-Al2O3 supports prepared by powder compaction and sintering, the halloysite nanotube-based mats (HNMs) show higher flux, better adsorption of zeolite seeds, adhesion of zeolite membranes and lower Al leaching. Four types of zeolite membranes supported on HNMs have been successfully synthesized with either in situ crystallization or a secondary growth method, demonstrating good universality of HNMs for supporting zeolite membranes.
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Controls on O2 Production in Cyanobacterial Mats and Implications for Earth's Oxygenation
Dick, Gregory J.; Grim, Sharon L.; Klatt, Judith M.
2018-05-01
Cyanobacterial mats are widely assumed to have been globally significant hot spots of biogeochemistry and evolution during the Archean and Proterozoic, but little is known about their quantitative contributions to global primary productivity or Earth's oxygenation. Modern systems show that mat biogeochemistry is the outcome of concerted activities and intimate interactions between various microbial metabolisms. Emerging knowledge of the regulation of oxygenic and sulfide-driven anoxygenic photosynthesis by versatile cyanobacteria, and their interactions with sulfur-oxidizing bacteria and sulfate-reducing bacteria, highlights how ecological and geochemical processes can control O2 production in cyanobacterial mats in unexpected ways. This review explores such biological controls on O2 production. We argue that the intertwined effects of light availability, redox geochemistry, regulation and competition of microbial metabolisms, and biogeochemical feedbacks result in emergent properties of cyanobacterial mat communities that are all critical yet largely overlooked mechanisms to potentially explain the protracted nature of Earth's oxygenation.
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Li, Xu; Yu, Kai; He, Bin
2016-01-01
Magnetoacoustic tomography with magnetic induction (MAT-MI) is a noninvasive imaging method developed to map electrical conductivity of biological tissue with millimeter level spatial resolution. In MAT-MI, a time-varying magnetic stimulation is applied to induce eddy current inside the conductive tissue sample. With the existence of a static magnetic field, the Lorentz force acting on the induced eddy current drives mechanical vibrations producing detectable ultrasound signals. These ultrasound signals can then be acquired to reconstruct a map related to the sample’s electrical conductivity contrast. This work reviews fundamental ideas of MAT-MI and major techniques developed in these years. First, the physical mechanisms underlying MAT-MI imaging are described including the magnetic induction and Lorentz force induced acoustic wave propagation. Second, experimental setups and various imaging strategies for MAT-MI are reviewed and compared together with the corresponding experimental results. In addition, as a recently developed reverse mode of MAT-MI, magneto-acousto-electrical tomography with magnetic induction (MAET-MI) is briefly reviewed in terms of its theory and experimental studies. Finally, we give our opinions on existing challenges and future directions for MAT-MI research. With all the reported and future technical advancement, MAT-MI has the potential to become an important noninvasive modality for electrical conductivity imaging of biological tissue. PMID:27542088
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Energy Technology Data Exchange (ETDEWEB)
Hernandez M, V.; Tavera D, M.L. [Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, 11801 Mexico D.F. (Mexico)
1997-07-01
This work treats over the performance and applications of the Varian Mat-250 mass spectrometer which is in the environmental isotope laboratory. It can be applied over topics such as: ions formation, acceleration and collimation, ions separation, ions detection, data transformation, sampling, {delta} notation. (Author)
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Hepatitis A through E (Viral Hepatitis)
... Treatment Eating, Diet, & Nutrition Clinical Trials Wilson Disease Hepatitis (Viral) View or Print All Sections What is Viral Hepatitis? Viral hepatitis is an infection that causes liver inflammation ...
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Alnajjar, Mohammad Ahmad; Ramette, Alban; Kü hl, Michael; Hamza, Waleed; Klatt, Judith M.; Polerecky, Lubos
2014-01-01
We imaged reflectance and variable fluorescence in 25 cyanobacterial mats from four distant sites around the globe to assess, at different scales of resolution, spatial variabilities in the physiological parameters characterizing their photosynthetic capacity, including the absorptivity by chlorophyll a (Achl), maximum quantum yield of photosynthesis (Ymax), and light acclimation irradiance (Ik). Generally, these parameters significantly varied within individual mats on a sub-millimeter scale, with about 2-fold higher variability in the vertical than in the horizontal direction. The average vertical profiles of Ymax and Ik decreased with depth in the mat, while Achl exhibited a sub-surface maximum. The within-mat variability was comparable to, but often larger than, the between-sites variability, whereas the within-site variabilities (i.e., between samples from the same site) were generally lowest. When compared based on averaged values of their photosynthetic parameters, mats clustered according to their site of origin. Similar clustering was found when the community composition of the mats' cyanobacterial layers were compared by automated ribosomal intergenic spacer analysis (ARISA), indicating a significant link between the microbial community composition and function. Although this link is likely the result of community adaptation to the prevailing site-specific environmental conditions, our present data is insufficient to identify the main factors determining these patterns. Nevertheless, this study demonstrates that the spatial variability in the photosynthetic capacity and light acclimation of benthic phototrophic microbial communities is at least as large on a sub-millimeter scale as it is on a global scale, and suggests that this pattern of variability scaling is similar for the microbial community composition. © 2014 Al-Najjar, Ramette, Kühl, Hamza, Klatt and Polerecky.
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Alnajjar, Mohammad Ahmad
2014-08-06
We imaged reflectance and variable fluorescence in 25 cyanobacterial mats from four distant sites around the globe to assess, at different scales of resolution, spatial variabilities in the physiological parameters characterizing their photosynthetic capacity, including the absorptivity by chlorophyll a (Achl), maximum quantum yield of photosynthesis (Ymax), and light acclimation irradiance (Ik). Generally, these parameters significantly varied within individual mats on a sub-millimeter scale, with about 2-fold higher variability in the vertical than in the horizontal direction. The average vertical profiles of Ymax and Ik decreased with depth in the mat, while Achl exhibited a sub-surface maximum. The within-mat variability was comparable to, but often larger than, the between-sites variability, whereas the within-site variabilities (i.e., between samples from the same site) were generally lowest. When compared based on averaged values of their photosynthetic parameters, mats clustered according to their site of origin. Similar clustering was found when the community composition of the mats\\' cyanobacterial layers were compared by automated ribosomal intergenic spacer analysis (ARISA), indicating a significant link between the microbial community composition and function. Although this link is likely the result of community adaptation to the prevailing site-specific environmental conditions, our present data is insufficient to identify the main factors determining these patterns. Nevertheless, this study demonstrates that the spatial variability in the photosynthetic capacity and light acclimation of benthic phototrophic microbial communities is at least as large on a sub-millimeter scale as it is on a global scale, and suggests that this pattern of variability scaling is similar for the microbial community composition. © 2014 Al-Najjar, Ramette, Kühl, Hamza, Klatt and Polerecky.
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A Process for the Creation of T-MATS Propulsion System Models from NPSS data
Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Jonathan S.; Guo, Ten-Huei
2014-01-01
A modular thermodynamic simulation package called the Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) has been developed for the creation of dynamic simulations. The T-MATS software is designed as a plug-in for Simulink (Math Works, Inc.) and allows a developer to create system simulations of thermodynamic plants (such as gas turbines) and controllers in a single tool. Creation of such simulations can be accomplished by matching data from actual systems, or by matching data from steady state models and inserting appropriate dynamics, such as the rotor and actuator dynamics for an aircraft engine. This paper summarizes the process for creating T-MATS turbo-machinery simulations using data and input files obtained from a steady state model created in the Numerical Propulsion System Simulation (NPSS). The NPSS is a thermodynamic simulation environment that is commonly used for steady state gas turbine performance analysis. Completion of all the steps involved in the process results in a good match between T-MATS and NPSS at several steady state operating points. Additionally, the T-MATS model extended to run dynamically provides the possibility of simulating and evaluating closed loop responses.
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Thermal Protection System Materials (TPSM): 3D MAT
National Aeronautics and Space Administration — The 3D MAT Project seeks to design and develop a game changing Woven Thermal Protection System (TPS) technology tailored to meet the needs of the Orion Multi-Purpose...
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Decker, K. L.; Potter, C.; Hoehler, T.
2005-12-01
The well-documented assumption about methanogens that co-occur in hypersaline mat communities with sulfate-reducing bacteria (SRB) is that they rely entirely on non-competitive substrates for methanogenesis. The reason for this is that during sulfate reduction, sulfur-reducing bacteria efficiently utilize H2, leaving a concentration too low for methanogenesis. Early results from recent work on a hypersaline microbial mat from salt evaporation ponds of Guerrero Negro, Baja, Mexico cast doubt that methanogenesis only occurs via non-competitive substrates, because it shows an excess of H2 in the mat rather than a paucity. We explore the use of our simulation model of the microbial biogeochemistry of a hypersaline mat (named MBGC) to compare methane production rates in a 1 cm thick mat when the methanogens use competitive substrates versus noncompetitive substrates. In the `non-competitive substrate' version of the model, methanogens rely exclusively on methylated amines that are accumulated as compatible solutes in cyanobacteria and released after lysis. In contrast, the `competitive substrate' models examine methanogen use of substrates (such as H2 + acetate) with different SRB population sizes (from absent to low). The comparison of these models of methane and sulfide biogeochemistry of a hypersaline mat has both ecological and geobiological significance, as one hypothesis of Archean microbial mats is that they existed in a low sulfate environment.
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Isolated hepatic actinomycosis: a case report
Directory of Open Access Journals (Sweden)
Shehab Thomas M
2010-02-01
Full Text Available Abstract Introduction Actinomyces are slow growing, non-spore forming, gram-positive, branching bacilli that thrive in anaerobic and microareophilic conditions. Actinomyces are more commonly associated with oral and cervicofacial infections. Hepatic involvement in infections of the abdomen (known as isolated hepatic actinomycosis is rare, accounting for only 5% of all cases of actinomycosis. Case presentation We present the case of a 75-year-old Caucasian woman with a 3-month history of night sweats, fever, chills, abdominal bloating, anorexia, weight-loss, and early satiety. The patient was found to have isolated hepatic actinomycosis infection after undergoing a laparotomy with a biopsy of the liver. The patient has now recovered. Conclusion Isolated hepatic actinomycosis is a rare and often overlooked etiology for a liver mass. Given its subacute presentation and nondescript symptomatology, physicians should be aware of this differential and the potential pitfalls in diagnosis and management.
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Total mercury and methyl-mercury contents and accumulation in polar microbial mats.
Camacho, Antonio; Rochera, Carlos; Hennebelle, Raphaëlle; Ferrari, Christophe; Quesada, Antonio
2015-03-15
Although polar regions are considered isolated and pristine areas, the organisms that inhabit these zones are exposed to global pollution. Heavy metals, such as mercury, are global pollutants and can reach almost any location on Earth. Mercury may come from natural, volcanic or geological sources, or result from anthropogenic sources, in particular industrial or mining activities. In this study, we have investigated one of the most prominent biological non-marine communities in both polar regions, microbial mats, in terms of their Hg and methyl-mercury (MeHg) concentrations and accumulation capacities. The main hypotheses posed argued on the importance of different factors, and to test them, we have measured Hg concentrations in microbial mats that were collected from 6 locations in different ecological situations. For this purpose, the direct anthropogenic impacts, volcanic influences, proximity to the seashore, latitudinal gradients and C contents were investigated. Our results show that, other than the direct anthropogenic influence, none of the other hypotheses alone satisfactorily explains the Hg content in microbial mats. In contrast, the MeHg contents were noticeably different between the investigated locations, with a higher proportion of MeHg on the McMurdo Ice Shelf (Antarctica) and a lower proportion on Ward Hunt Island (High Arctic). Furthermore, our results from in situ experiments indicated that the microbial mats from South Shetland Islands could quickly accumulate (48 h) Hg when Hg dissolved salts were supplied. Over short-term periods, these mats do not transform Hg into MeHg under field conditions. Copyright © 2014 Elsevier B.V. All rights reserved.
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Diatom-driven recolonization of microbial mat-dominated siliciclastic tidal flat sediments.
Pan, Jerónimo; Cuadrado, Diana G; Bournod, Constanza N
2017-10-01
Modern microbial mats and biofilms play a paramount role in sediment biostabilization. When sporadic storms affect tidal flats of Bahía Blanca Estuary, the underlying siliciclastic sediment is exposed by physical disruption of the mat, and in a few weeks' lapse, a microbial community re-establishes. With the objective of studying colonization patterns and the ecological succession of microorganisms at the scale of these erosional structures, these were experimentally made and their biological recolonization followed for 8 weeks, with replication in winter and spring. Motile pennate diatoms led the initial colonization following two distinct patterns: a dominance by Cylindrotheca closterium in winter and by naviculoid and nitzschioid diatoms in spring. During the first 7 days, cell numbers increased 2- to 17-fold. Cell densities further increased exhibiting sigmoidal community growth, reaching 2.9-8.9 × 106 cells cm-3 maxima around day 30; centric diatoms maintained low densities throughout. In 56 days after removal of the original mat, filamentous cyanobacteria that dominate mature mats did not establish a significant biomass, leading to the rejection of the hypothesis that cyanobacteria would drive the colonization. The observed dominance of pennate diatoms is attributed to extrinsic factors determined by tidal flooding, and intrinsic ones, e.g. motility, nutrient affinity and high growth rate. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.
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VISSCHER, PT; VANDENENDE, FP; SCHAUB, BEM; VANGEMERDEN, H
The populations of chemolithoautotrophic (colorless) sulfur bacteria and anoxygenic phototrophic bacteria were enumerated in a marine microbial mat. The highest population densities were found in the 0-5 mm layer of the mat: 2.0 X 10(9) cells CM-3 sediment, and 4.0 X 10(7) cells cm-3 sediment for
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Estimation of axial stiffness of plant fibres from compaction of non-woven mats
DEFF Research Database (Denmark)
Gamstedt, E. K.; Bommier, E.; Madsen, Bo
2014-01-01
-plane randomly oriented fibre mats. The model by Toll is used to relate the load-displacement curve from the test to the Young modulus of the fibre, taking into account the natural variability in fibre cross section. Several tests have been performed on hemp fibre mats and compared with results from single...
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Perfect simulation and moment properties for the Matérn type III process
DEFF Research Database (Denmark)
Møller, Jesper; Huber, Mark L.; Wolpert, Robert L.
In a seminal work, Bertil Matérn introduced several types of processes for modeling repulsive point processes. In this paper an algorithm is presented for the perfect simulation of the Mat´ern III process within a bounded window in Rd fully accounting for edge effects. A simple upper bound...
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Directory of Open Access Journals (Sweden)
S. Richard
2018-02-01
Full Text Available Fungi of the genus Pneumocystis are obligate parasites that colonize mammals’ lungs and are host species specific. Pneumocystis jirovecii and Pneumocystis carinii infect, respectively, humans and rats. They can turn into opportunistic pathogens in immunosuppressed hosts, causing severe pneumonia. Their cell cycle is poorly known, mainly because of the absence of an established method of culture in vitro. It is thought to include both asexual and sexual phases. Comparative genomic analysis suggested that their mode of sexual reproduction is primary homothallism involving a single mating type (MAT locus encompassing plus and minus genes (matMc, matMi, and matPi; Almeida et al., mBio 6:e02250-14, 2015. Thus, each strain would be capable of sexual reproduction alone (self-fertility. However, this is a working hypothesis derived from computational analyses that is, in addition, based on the genome sequences of single isolates. Here, we tested this hypothesis in the wet laboratory. The function of the P. jirovecii and P. carinii matMc genes was ascertained by restoration of sporulation in the corresponding mutant of fission yeast. Using PCR, we found the same single MAT locus in all P. jirovecii isolates and showed that all three MAT genes are often concomitantly expressed during pneumonia. Extensive homology searches did not identify other types of MAT transcription factors in the genomes or cis-acting motifs flanking the MAT locus that could have been involved in MAT switching or silencing. Our observations suggest that Pneumocystis sexuality through primary homothallism is obligate within host lungs to complete the cell cycle, i.e., produce asci necessary for airborne transmission to new hosts.
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Hepatitis isquémica Ischemic hepatitis
Directory of Open Access Journals (Sweden)
Marcos Amuchástegui (h
2006-10-01
Full Text Available La hepatitis isquémica es una complicación sumamente infrecuente de cirugía cardiovascular. Las biopsias muestran necrosis centrolobulillar. El término de "hepatitis" fue propuesto debido al aumento de transaminasas similar a aquellas de origen infeccioso, e "isquémica" por falla en la perfusión hepática. Posteriormente se definió el término de hepatitis isquémica como cuadro de elevación aguda y reversible (dentro de las 72 horas de transaminasas de hasta 20 veces el valor normal, asociado a trastornos en la perfusión hepática, luego de haber excluido otras causas de hepatitis aguda o daño hepatocelular. Se describe el caso de un paciente de 53 años que consulta por dolor epigástrico de 12 h de evolución sin fiebre, náuseas ni vómitos, resistente a la medicación. Tenía antecedentes inmediatos de reemplazo de válvula aórtica, y estaba anticoagulado. Evolucionó con shock y fallo multiorgánico. El examen evidenció marcada ictericia y signos de taponamiento pericárdico, asociado a un aumento considerable de enzimas hepáticas. Un ecocardiograma informó signos de taponamiento cardíaco y ausencia de disección aórtica. Se decidió pericardiocentesis, extrayéndose 970 cc. de líquido sanguinolento, y hemodiálisis, con notable mejoría de su estado hemodinámico. Los valores enzimáticos disminuyeron. Los marcadores virales fueron negativos.Ischemic hepatitis is an uncommon cardiovascular surgery complication. Hepatic biopsies show centrolobulillar necrosis. The term "hepatitis" was proposed because of a raise in hepatic enzymes similar with infectious disease, and "ischemic" because of failure in hepatic perfusion. Ischemic hepatitis was then defined as an acute and reversible elevation of hepatic enzymes (within 72 h, associated with disturbance in hepatic perfusion after excluding other causes of acute hepatitis. A 53 year-old male presented complaining of a 12 h epigastric pain, without nausea or vomiting, resistant
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Directory of Open Access Journals (Sweden)
Lakshminarayanan R
2014-05-01
Full Text Available Rajamani Lakshminarayanan,1,2 Radhakrishnan Sridhar,3,4 Xian Jun Loh,5 Muruganantham Nandhakumar,1 Veluchamy Amutha Barathi,1,6 Madhaiyan Kalaipriya,3,4 Jia Lin Kwan,1 Shou Ping Liu,1,2 Roger Wilmer Beuerman,1,2 Seeram Ramakrishna3,4,7 1Singapore Eye Research Institute, 2Signature Research Program in Neuroscience and Behavioral Disorders, Duke-NUS Graduate Medical School, 3Department of Mechanical Engineering, National University of Singapore, 4Center for Nanofibers and Nanotechnology, National University of Singapore, 5Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research, 3 Research Link, Singapore, 6Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, 7NUS Nanoscience and Nanotechnology Initiative, Singapore Abstract: Topical application of antifungals does not have predictable or well-controlled release characteristics and requires reapplication to achieve therapeutic local concentration in a reasonable time period. In this article, the efficacy of five different US Food and Drug Administration-approved antifungal-loaded (amphotericin B, natamycin, terbinafine, fluconazole, and itraconazole electrospun gelatin fiber mats were compared. Morphological studies show that incorporation of polyenes resulted in a two-fold increase in fiber diameter and the mats inhibit the growth of yeasts and filamentous fungal pathogens. Terbinafine-loaded mats were effective against three filamentous fungal species. Among the two azole antifungals compared, the itraconazole-loaded mat was potent against Aspergillus strains. However, activity loss was observed for fluconazole-loaded mats against all of the test organisms. The polyene-loaded mats displayed rapid candidacidal activities as well. Biophysical and rheological measurements indicate strong interactions between polyene antifungals and gelatin matrix. As a result, the polyenes stabilized the triple helical
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Gro2mat: a package to efficiently read gromacs output in MATLAB.
Dien, Hung; Deane, Charlotte M; Knapp, Bernhard
2014-07-30
Molecular dynamics (MD) simulations are a state-of-the-art computational method used to investigate molecular interactions at atomic scale. Interaction processes out of experimental reach can be monitored using MD software, such as Gromacs. Here, we present the gro2mat package that allows fast and easy access to Gromacs output files from Matlab. Gro2mat enables direct parsing of the most common Gromacs output formats including the binary xtc-format. No openly available Matlab parser currently exists for this format. The xtc reader is orders of magnitudes faster than other available pdb/ascii workarounds. Gro2mat is especially useful for scientists with an interest in quick prototyping of new mathematical and statistical approaches for Gromacs trajectory analyses. © 2014 Wiley Periodicals, Inc. Copyright © 2014 Wiley Periodicals, Inc.
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International Nuclear Information System (INIS)
Wadawale, A.; Chopade, S.; Chaudhury, K.; Pal, M.K.; Kushwah, N.; Shah, A.Y.; Kedarnath, G.; Priyadarsini, K.I.; Jain, V.K.
2017-01-01
MAT Lab of Chemistry Division, BARC (A Class 10000 Clean room laboratory) has been in operation since 2004 for process development of ultra-purification of several strategically important materials (Ga, As, Sb, In, CsI and Ge) and synthesis of their organometallic compounds. Of these, work related to purification of As, Sb, and In, has been discontinued. Due to high toxicity and pyrophoric nature of some of the compounds, stringent safety regulations were formulated and subsequently implemented by the division
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International Nuclear Information System (INIS)
Takayasu, K.; Moriyama, N.; Muramatsu, Y.
1985-01-01
When the inferior vena cava is obstructed, collateral veins enlarge, connecting with the inferior (acessory) right hepatic vein (IRHV) and thence through various hepatic veins to the right atrium. Three such cases are described. In one patient, most contrast material flowed into the IRHV and from there to the left hepatic vein. The second patient had several large collaterals arising from the IRHV and flowing into the right and middle hepatic veins, while the third patient demonstrated anastomoses between the IRHV and the middle hepatic vein. All of these hepatic venous shunts eventually drained into the right atrium. There were no clinical manifestations such as ascites, edema, or dilatation of the abdominal veins. Cavography alone or combined with computed tomography proved to be diagnostic in the assessment of these intrahepatic collaterals
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Sheng, Xiaoyue; Fan, Linpeng; He, Chuanglong; Zhang, Kuihua; Mo, Xiumei; Wang, Hongsheng
2013-05-01
In the present study, we reported fabrication and skin benefit of a novel vitamin E (VE)-loaded silk fibroin (SF) nanofibrous mats. RRR-α-Tocopherol polyethylene glycol 1000 succinate (VE TPGS), a water-soluble derivative of VE, was incorporated into SF nanofiber successfully by aqua solution electrospinning for the first time. Morphology of the composite nanofibers changed with the different amount of VE TPGS: a ribbon-like shape for lower loading dose of VE TPGS, while a round shape for higher loading dose (more than 4% (wt/wt) based on the weight of SF). After treated with 75% (v/v) ethanol vapor, the composite nanofibrous mats showed an excellent water-resistant ability. In vitro study disclosed a sustained release behavior of VE TPGS disassociated from the nanofibrous mats. The mouse skin fibroblasts (L929 cells) cultured on the VE-loaded SF nanofibrous mats spread and proliferated much better than on cover slips. Moreover, the incorporation of VE TPGS was found strengthening the ability of SF nanofibrous mats on protecting the cells against oxidation stress induced by tert-butyl hydroperoxide. Our data presented impressive skin benefits of this VE-loaded SF nanofibrous mats, suggesting a promising applicative potential of this novel product on personal skin care, tissue regeneration and other related area. Copyright © 2013 Elsevier B.V. All rights reserved.
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Directory of Open Access Journals (Sweden)
Kevin W. Hager
2017-08-01
Full Text Available The Mariana region exhibits a rich array of hydrothermal venting conditions in a complex geological setting, which provides a natural laboratory to study the influence of local environmental conditions on microbial community structure as well as large-scale patterns in microbial biogeography. We used high-throughput amplicon sequencing of the bacterial small subunit (SSU rRNA gene from 22 microbial mats collected from four hydrothermally active locations along the Mariana Arc and back-arc to explore the structure of lithotrophically-based microbial mat communities. The vent effluent was classified as iron- or sulfur-rich corresponding with two distinct community types, dominated by either Zetaproteobacteria or Epsilonproteobacteria, respectively. The Zetaproteobacterial-based communities had the highest richness and diversity, which supports the hypothesis that Zetaproteobacteria function as ecosystem engineers creating a physical habitat within a chemical environment promoting enhanced microbial diversity. Gammaproteobacteria were also high in abundance within the iron-dominated mats and some likely contribute to primary production. In addition, we also compare sampling scale, showing that bulk sampling of microbial mats yields higher diversity than micro-scale sampling. We present a comprehensive analysis and offer new insights into the community structure and diversity of lithotrophically-driven microbial mats from a hydrothermal region associated with high microbial biodiversity. Our study indicates an important functional role of for the Zetaproteobacteria altering the mat habitat and enhancing community interactions and complexity.
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Maruthachalam, Karunakaran; Wu, Bo-Ming; Subbarao, Krishna V.
2013-01-01
Sclerotinia sclerotiorum is a fungal plant pathogen and the causal agent of lettuce drop, an economically important disease of California lettuce. The structure of the S. sclerotiorum mating type locus MAT has previously been reported and consists of two idiomorphs that are fused end-to-end as in other homothallics. We investigated the diversity of S. sclerotiorum MAT using a total of 283 isolates from multiple hosts and locations, and identified a novel MAT allele that differed by a 3.6-kb inversion and was designated Inv+, as opposed to the previously known S. sclerotiorum MAT that lacked the inversion and was Inv-. The inversion affected three of the four MAT genes: MAT1-2-1 and MAT1-2-4 were inverted and MAT1-1-1 was truncated at the 3’-end. Expression of MAT genes differed between Inv+ and Inv- isolates. In Inv+ isolates, only one of the three MAT1-2-1 transcript variants of Inv- isolates was detected, and the alpha1 domain of Inv+ MAT1-1-1 transcripts was truncated. Both Inv- and Inv+ isolates were self-fertile, and the inversion segregated in a 1∶1 ratio regardless of whether the parent was Inv- or Inv+. This suggested the involvement of a highly regulated process in maintaining equal proportions of Inv- and Inv+, likely associated with the sexual state. The MAT inversion region, defined as the 3.6-kb MAT inversion in Inv+ isolates and the homologous region of Inv- isolates, was flanked by a 250-bp inverted repeat on either side. The 250-bp inverted repeat was a partial MAT1-1-1 that through mediation of loop formation and crossing over, may be involved in the inversion process. Inv+ isolates were widespread, and in California and Nebraska constituted half of the isolates examined. We speculate that a similar inversion region may be involved in mating type switching in the filamentous ascomycetes Chromocrea spinulosa, Sclerotinia trifoliorum and in certain Ceratocystis species. PMID:23457637
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Jung, Mi-Hee
2017-11-01
ZnO has had little consideration as an anode material in lithium-ion batteries compared with other transition-metal oxides due to its inherent poor electrical conductivity and large volume expansion upon cycling and pulverization of ZnO-based electrodes. A logical design and facile synthesis of ZnO with well-controlled particle sizes and a specific morphology is essential to improving the performance of ZnO in lithium-ion batteries. In this paper, a simple approach is reported that uses a cation surfactant and a chelating agent to synthesize three-dimensional hierarchical nanostructured carbon-coated ZnO mats, in which the ZnO mats are composed of stacked individual ZnO nanowires and form well-defined nanoporous structures with high surface areas. In order to improve the performance of lithium-ion batteries, HfO 2 is deposited on the carbon-coated ZnO mat electrode via atomic layer deposition. Lithium-ion battery devices based on the carbon-coated ZnO mat passivation by atomic layer deposited HfO 2 exhibit an excellent initial discharge and charge capacities of 2684.01 and 963.21mAhg -1 , respectively, at a current density of 100mAg -1 in the voltage range of 0.01-3V. They also exhibit cycle stability after 125 cycles with a capacity of 740mAhg -1 and a remarkable rate capability. Copyright © 2017 Elsevier Inc. All rights reserved.
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Full Text Available ... Related Liver Disease Alpha-1 Antitrypsin Deficiency Autoimmune Hepatitis Benign Liver Tumors Biliary Atresia Cirrhosis of the ... Disease Type 1 (von Gierke) Hemochromatosis Hepatic Encephalopathy Hepatitis A Hepatitis B Hepatitis C Intrahepatic Cholestasis of ...
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Full Text Available ... Hemochromatosis Hepatic Encephalopathy Hepatitis A Hepatitis B Hepatitis C Intrahepatic Cholestasis of Pregnancy (ICP) Jaundice In Newborns ... are the common causes of cirrhosis? Hepatitis B & C Alcohol-related Liver Disease Non-alcoholic Fatty Liver ...
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Bandyopadhyay, S.; Cahay, M.
2006-01-01
In a recent e-print [cond-mat/0603260] Hall and Flatte claim that a particular spin based field effect transistor (SPINFET), which they have analyzed, will have a lower threshold voltage, lower switching energy and lower leakage current than a comparable metal oxide semiconductor field effect transistor (MOSFET). Here, we show that all three claims of HF are invalid.
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Directory of Open Access Journals (Sweden)
Arjun eChennu
2015-12-01
Full Text Available Desiccated cyanobacterial mats are the dominant biological feature in the Earth's arid zones. While the response of desiccated cyanobacteria to rehydration is well documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 minutes after rehydration chlorophyll a concentrations increased 2-5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min – 48 h involved migration of the reactivated cyanobacteria towards the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and aquatic origin. However the response of upward migration and its triggering factor appears to be mat-specific and likely linked to other factors.
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Chennu, Arjun
2015-12-24
Desiccated cyanobacterial mats are the dominant biological feature in the Earth’s arid zones. While the response of desiccated cyanobacteria to rehydration is well-documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors, and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 min after rehydration chlorophyll a concentrations increased 2–5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min–48 h) involved migration of the reactivated cyanobacteria toward the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and marine origin. However, the response of upward migration and its triggering factor appear to be mat-specific and likely linked to other factors.
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Chennu, Arjun; Grinham, Alistair; Polerecky, Lubos; de Beer, Dirk; Alnajjar, Mohammad Ahmad
2015-01-01
Desiccated cyanobacterial mats are the dominant biological feature in the Earth’s arid zones. While the response of desiccated cyanobacteria to rehydration is well-documented for terrestrial systems, information about the response in marine systems is lacking. We used high temporal resolution hyperspectral imaging, liquid chromatography, pulse-amplitude fluorometry, oxygen microsensors, and confocal laser microscopy to study this response in a desiccated microbial mat from Exmouth Gulf, Australia. During the initial 15 min after rehydration chlorophyll a concentrations increased 2–5 fold and cyanobacterial photosynthesis was re-established. Although the mechanism behind this rapid increase of chlorophyll a remains unknown, we hypothesize that it involves resynthesis from a precursor stored in desiccated cyanobacteria. The subsequent phase (15 min–48 h) involved migration of the reactivated cyanobacteria toward the mat surface, which led, together with a gradual increase in chlorophyll a, to a further increase in photosynthesis. We conclude that the response involving an increase in chlorophyll a and recovery of photosynthetic activity within minutes after rehydration is common for cyanobacteria from desiccated mats of both terrestrial and marine origin. However, the response of upward migration and its triggering factor appear to be mat-specific and likely linked to other factors.
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Full Text Available ... 1 (von Gierke) Hemochromatosis Hepatic Encephalopathy Hepatitis A Hepatitis B Hepatitis C Intrahepatic Cholestasis of Pregnancy (ICP) Jaundice ... diseases. What are the common causes of cirrhosis? Hepatitis B & C Alcohol-related Liver Disease Non-alcoholic Fatty ...
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Directory of Open Access Journals (Sweden)
Valerie Bríd O’Leary
2015-04-01
Full Text Available Exposure to low-dose irradiation causes transiently elevated expression of the long ncRNA PARTICLE (gene PARTICLE, promoter of MAT2A-antisense radiation-induced circulating lncRNA. PARTICLE affords both a cytosolic scaffold for the tumor suppressor methionine adenosyltransferase (MAT2A and a nuclear genetic platform for transcriptional repression. In situ hybridization discloses that PARTICLE and MAT2A associate together following irradiation. Bromouridine tracing and presence in exosomes indicate intercellular transport, and this is supported by ex vivo data from radiotherapy-treated patients. Surface plasmon resonance indicates that PARTICLE forms a DNA-lncRNA triplex upstream of a MAT2A promoter CpG island. We show that PARTICLE represses MAT2A via methylation and demonstrate that the radiation-induced PARTICLE interacts with the transcription-repressive complex proteins G9a and SUZ12 (subunit of PRC2. The interplay of PARTICLE with MAT2A implicates this lncRNA in intercellular communication and as a recruitment platform for gene-silencing machineries through triplex formation in response to irradiation.
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Counting viruses and bacteria in photosynthetic microbial mats
Carreira, C; Staal, M.; Middelboe, M.; Brussaard, C.P.D.
2015-01-01
Viral abundances in benthic environments are the highest found in aquatic systems. Photosynthetic microbial mats represent benthic environments with high microbial activity and possibly high viral densities, yet viral abundances have not been examined in such systems. Existing extraction procedures
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Otaki, Hiroyo; Everroad, R. Craig; Matsuura, Katsumi; Haruta, Shin
2012-01-01
Microbial mats containing the filamentous anoxygenic photosynthetic bacterium Chloroflexus aggregans develop at Nakabusa hot spring in Japan. Under anaerobic conditions in these mats, interspecies interaction between sulfate-reducing bacteria as sulfide producers and C. aggregans as a sulfide consumer has been proposed to constitute a sulfur cycle; however, the electron donor utilized for microbial sulfide production at Nakabusa remains to be identified. In order to determine this electron donor and its source, ex situ experimental incubation of mats was explored. In the presence of molybdate, which inhibits biological sulfate reduction, hydrogen gas was released from mat samples, indicating that this hydrogen is normally consumed as an electron donor by sulfate-reducing bacteria. Hydrogen production decreased under illumination, indicating that C. aggregans also functions as a hydrogen consumer. Small amounts of hydrogen may have also been consumed for sulfur reduction. Clone library analysis of 16S rRNA genes amplified from the mats indicated the existence of several species of hydrogen-producing fermentative bacteria. Among them, the most dominant fermenter, Fervidobacterium sp., was successfully isolated. This isolate produced hydrogen through the fermentation of organic carbon. Dispersion of microbial cells in the mats resulted in hydrogen production without the addition of molybdate, suggesting that simultaneous production and consumption of hydrogen in the mats requires dense packing of cells. We propose a cyclic electron flow within the microbial mats, i.e., electron flow occurs through three elements: S (elemental sulfur, sulfide, sulfate), C (carbon dioxide, organic carbon) and H (di-hydrogen, protons). PMID:22446313
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Smart monitoring of fluid intake and bladder voiding using pressure sensitive mats.
Cohen-McFarlane, Madison; Green, James R; Knoefel, Frank; Goubran, Rafik
2016-08-01
Pressure sensitive mats have been used in noninvasive smart monitoring for a variety of problems including breathing rate monitoring, sleep monitoring, mobility, and weight. This paper describes a proof of concept application of pressure mats to monitor fluid intake/output (fluid cycle) events during the night. The ability to more accurately track such events has potential implications for monitoring those individuals who have nocturia, a condition where a person wakes at night to urinate. Data were collected from a healthy young female subject instructed to drink as much water as was comfortable (700mL) and lie in a supine position on a mattress located directly on three pressure mats. This was compared to an initial data set collected immediately after voiding but before drinking, 30 minutes after drinking, 60 minutes after drinking and a final data set after again voiding the bladder. The additional pressure from the 700mL of water was detectible and tracked over the course of the hour-long testing session under idealized conditions. This provides a proof-of-concept that nocturnal fluid intake and bladder voiding events can be tracked using non-invasive pressure-sensitive mats, however additional testing and development is required to achieve a deployable monitoring system.
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Han, Chao
The threat of oil pollution increases with the expansion of oil exploration and production activities, as well as the industrial growth around the world. Use of sorbents is a common method to deal with the oil spills. In this work, an advanced sorbent technology is described. A series of non-woven Cellulose Acetate (CA) nanofibrous mats with a 3D fibrous structure were synthesized by a novel high-throughput electrospinning technique. The precursor was solutions of CA/ acetic acid-acetone in various concentrations. Among them, 15.0% CA exhibits a superhydrophobic surface property, with a water contact angle of 128.95°. Its oil sorption capacity is many times higher the oil sorption capacity of the best commercial sorbent available in the market. Also, it showed good buoyancy properties on the water both as dry-mat and oil-saturated mat. In addition, it is biodegradable, easily available, easily manufactured, so the CA nanofibrous mat is an excellent candidate as oil sorbent for oil spill in water treatment.
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Millimeter Wavelength Observations of Galactic Sources with the Mobile Anisotropy Telescope (MAT)
Cruz, K. L.; Caldwell, R.; Devlin, M. J.; Dorwart, W. B.; Herbig, T.; Miller, A. D.; Nolta, M. R.; Page, L. A.; Puchalla, J. L.; Torbet, E.; Tran, H. T.
1999-12-01
The Mobile Anisotropy Telescope (MAT) has completed two observing seasons (1997 and 1998) in Chile from the Cerro Toco site. Although the primary goal of MAT was to measure anisotropy in the Cosmic Microwave Background (CMB) radiation, the chosen observation scheme also allowed daily viewing of the Galactic Plane. We present filtered maps at 30, 40 and 144 GHz of a region of the Galactic Plane which contains several millimeter-bright regions including the Carinae nebula and IRAS 11097-6102. We report the best fit brightness temperatures as well as the total flux densities in the MAT beams (0.9, 0.6 and 0.2 degrees FWHM) . The data are calibrated with respect to Jupiter whose flux is known to better than 8% in all frequency bands. This work was funded by the National Science Foundation and the Packard Foundation.
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Jain, P; Prakash, S; Gupta, S; Singh, K P; Shrivastava, S; Singh, D D; Singh, J; Jain, A
2013-01-01
Acute viral hepatitis (AVH) is a major public health problem and is an important cause of morbidity and mortality. The aim of the present study is to determine the prevalence of hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and hepatitis E virus (HEV) as causes of AVH in a tertiary care hospital of North India. Blood samples and clinical information was collected from cases of AVH referred to the Grade I viral diagnostic laboratory over a 1-year period. Samples were tested for hepatitis B surface antigen, anti-HCV total antibodies, anti-HAV immunoglobulin M (IgM) and anti-HEV IgM by the enzyme-linked immunosorbent assay. PCR for nucleic acid detection of HBV and HCV was also carried out. Those positive for HBV infection were tested for anti-HDV antibodies. Fisher's exact test was used and a P hepatitis cases, 62 (23.22%) patients presented as acute hepatic failure. HAV (26.96%) was identified as the most common cause of acute hepatitis followed by HEV (17.97%), HBV (16.10%) and HCV (11.98%). Co-infections with more than one virus were present in 34 cases; HAV-HEV co-infection being the most common. HEV was the most important cause of acute hepatic failure followed by co-infection with HAV and HEV. An indication towards epidemiological shift of HAV infection from children to adults with a rise in HAV prevalence was seen. To the best of our knowledge, this is the first report indicating epidemiological shift of HAV in Uttar Pradesh.
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Mats and LaSpec: High-precision experiments using ion traps and lasers at Fair
Energy Technology Data Exchange (ETDEWEB)
Rodriguez, D.; Lallena, A.M.; Blaum, K.; Bohm, C.; Cakirli, R.B.; Crespo Lopez-Urrutia, J.R.; Eliseev, S.; Ketelaer, J.; Kreim, M.S.; Kowalska, M.; Litvinov, Y.A.; Nagy, S.; Neidherr, D.; Repp, J.; Roux, C.; Schabinger, B.; Ullrich, J.; Nortershauser, W.; Eberhardt, K.; Geppert, C.; Kramer, J.; Krieger, A.; Sanchez, R.; Ahammed, M.; Das, P.; Ray, A.; Algora, A.; Rubio, B.; Tain, J.L.; Audi, G.; Lunney, D.; Naimi, S.; Aysto, J.; Jokinen, A.; Kolhinen, V.; Moore, I.; Beck, D.; Block, M.; Geissel, H.; Heinz, S.; Herfurth, F.; Litvinov, Y.A.; Minaya-Ramirez, E.; Plab, W.R.; Quint, W.; Scheidenberger, C.; Winkler, M.; Bender, M.; Billowes, J.; Campbell, P.; Flanagan, K.T.; Schwarz, S.; Bollen, G.; Ferrer, R.; George, S.; Kester, O.; Brodeur, M.; Brunner, T.; Delheij, P.; Dilling, J.; Ettenauer, S.; Lapierre, A.; Bushaw, B.A.; Cano-Ott, D.; Martinez, T.; Cortes, G.; Gomez-Hornillos, M.B.; Dax, A.; Herlert, A.; Yordanov, D.; De, A.; Dickel, T.; Geissel, H.; Jesch, C.; Kuhl, T.; Petrick, M.; PlaB, W.R.; Scheidenberger, C.; Garcia-Ramos, J.E.; Gartzke, E.; Habs, D.; Szerypo, J.; Thirolf, P.G.; Weber, C.; Gusev, Y.; Nesterenko, D.; Novikov, Y.N.; Popov, A.; Seliverstov, M.; Vasiliev, A.; Vorobjev, G.; Heenen, P.H.; Marx, G.; Schweikhard, L.; Ziegler, F.; Hobein, M.; Schuch, R.; Solders, A.; Suhonen, M.; Huber, G.; Wendt, K.; Huyse, M.; Koudriavtsev, I.; Neyens, G.; Van Duppen, P.; Le Blanc, F.; Matos, M.; Reinhard, P.G.; Schneider, D.
2010-05-15
Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. With MATS (Precision Measurements of very short-lived nuclei using an Advanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10{sup -9} can be reached by employing highly-charged ions and a non-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. Decay studies in ion traps will become possible with MATS. Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The accuracy of laser-spectroscopic-determined nuclear properties is very high while requirements concerning production rates are moderate. This Technical Design Report describes a new Penning trap mass spectrometry setup as well as a number of complementary experimental devices for laser spectroscopy. Since MATS and LaSpec require high-quality low
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Mats and LaSpec: High-precision experiments using ion traps and lasers at Fair
International Nuclear Information System (INIS)
Rodriguez, D.; Lallena, A.M.; Blaum, K.; Bohm, C.; Cakirli, R.B.; Crespo Lopez-Urrutia, J.R.; Eliseev, S.; Ketelaer, J.; Kreim, M.S.; Kowalska, M.; Litvinov, Y.A.; Nagy, S.; Neidherr, D.; Repp, J.; Roux, C.; Schabinger, B.; Ullrich, J.; Nortershauser, W.; Eberhardt, K.; Geppert, C.; Kramer, J.; Krieger, A.; Sanchez, R.; Ahammed, M.; Das, P.; Ray, A.; Algora, A.; Rubio, B.; Tain, J.L.; Audi, G.; Lunney, D.; Naimi, S.; Aysto, J.; Jokinen, A.; Kolhinen, V.; Moore, I.; Beck, D.; Block, M.; Geissel, H.; Heinz, S.; Herfurth, F.; Litvinov, Y.A.; Minaya-Ramirez, E.; Plab, W.R.; Quint, W.; Scheidenberger, C.; Winkler, M.; Bender, M.; Billowes, J.; Campbell, P.; Flanagan, K.T.; Schwarz, S.; Bollen, G.; Ferrer, R.; George, S.; Kester, O.; Brodeur, M.; Brunner, T.; Delheij, P.; Dilling, J.; Ettenauer, S.; Lapierre, A.; Bushaw, B.A.; Cano-Ott, D.; Martinez, T.; Cortes, G.; Gomez-Hornillos, M.B.; Dax, A.; Herlert, A.; Yordanov, D.; De, A.; Dickel, T.; Geissel, H.; Jesch, C.; Kuhl, T.; Petrick, M.; PlaB, W.R.; Scheidenberger, C.; Garcia-Ramos, J.E.; Gartzke, E.; Habs, D.; Szerypo, J.; Thirolf, P.G.; Weber, C.; Gusev, Y.; Nesterenko, D.; Novikov, Y.N.; Popov, A.; Seliverstov, M.; Vasiliev, A.; Vorobjev, G.; Heenen, P.H.; Marx, G.; Schweikhard, L.; Ziegler, F.; Hobein, M.; Schuch, R.; Solders, A.; Suhonen, M.; Huber, G.; Wendt, K.; Huyse, M.; Koudriavtsev, I.; Neyens, G.; Van Duppen, P.; Le Blanc, F.; Matos, M.; Reinhard, P.G.; Schneider, D.
2010-01-01
Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. With MATS (Precision Measurements of very short-lived nuclei using an Advanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10 -9 can be reached by employing highly-charged ions and a non-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. Decay studies in ion traps will become possible with MATS. Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The accuracy of laser-spectroscopic-determined nuclear properties is very high while requirements concerning production rates are moderate. This Technical Design Report describes a new Penning trap mass spectrometry setup as well as a number of complementary experimental devices for laser spectroscopy. Since MATS and LaSpec require high-quality low-energy beams
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International Nuclear Information System (INIS)
Lin, H.J.; Chung, H.T.; Lai, C.L.; Leong, S.; Tam, O.S.
1989-01-01
A novel assay for supercoiled and other fully double-stranded forms of hepatitis B virus (HBV) DNA in blood is presented that utilizes molecular hybridisation to a radiophosphorous-labeled oligonucleotide probe. The probe [5'-d(ACGTGCAGAGGTGAAGCGA)] is complementary to the S(+)-strand sequence furthest downstream, at the end of the gap. We examined blood specimens from 137 healthy HBsAg-positive individuals, applying the probe to dots representing 2-3.5 ml serum or plasma. We found that supercoiled HBV is present in many HBV DNA-positive blood specimens albeit in small quantities. Of the 104 specimens that were positive for HBV DNA of any form, 53 annealed to the probe. Serial specimens from the same subject taken over a period of months showed that the proportion of supercoil to other HBV DNA forms was variable. The presence of supercoil HBV DNA was not closely correlated with the level of serum HBV DNA polymerase. The supercoil is an HBV DNA form that can persist in the liver in the presence or absence of other replicative intermediates. This assay may enable further characterization of the status of HBV infection
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Hepatitis delta in HIV-infected individuals in Europe
DEFF Research Database (Denmark)
Soriano, Vincent; Grint, Daniel; Monforte, Antonellad'arminio
2011-01-01
BACKGROUND:: Hepatitis delta virus (HDV) infection results in the most aggressive form of chronic viral hepatitis. There is scarce information about the prevalence, epidemiology, virological profile and natural historyof hepatitis delta in HIV patients. METHODS:: From 16,597 HIV patients enrolled......-RNA was quantified using a real-time PCR method. RESULTS:: A total of 61/422 HBsAg+ carriers were anti-HDV+ (prevalence: 14.5%). Hepatitis delta predominated in intravenous drug users and for this reason in South and/or East Europe. Serum HDV-RNA was detectable in 87% of tested anti-HDV+ patients, with a median...... titer of 1.76x10¿copies/ml. Overall, delta hepatitis patients showed lower serum HBV-DNA than the rest of HBsAg+ carriers, although the inhibitory effect of HDV on HBV replication was not recognized in HBV genotype D patients.Whereas HDV was not associated with progression to AIDS, it significantly...
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Directory of Open Access Journals (Sweden)
Narendiran Vitchuli, Quan Shi, Joshua Nowak, Kathryn Kay, Jane M Caldwell, Frederick Breidt, Mohamed Bourham, Marian McCord and Xiangwu Zhang
2011-01-01
Full Text Available ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning–electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99% against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95% against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning–electrospraying hybrid process are promising material candidates for protective applications.
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Energy Technology Data Exchange (ETDEWEB)
Vitchuli, Narendiran; Shi Quan; McCord, Marian; Zhang Xiangwu [Fiber and Polymer Science Program, Department of Textile Engineering, Chemistry and Science, North Carolina State University, Raleigh, NC 27695-8301 (United States); Nowak, Joshua; Bourham, Mohamed [Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695-7909 (United States); Kay, Kathryn [Department of Microbiology, North Carolina State University, Raleigh, NC 27695-7610 (United States); Caldwell, Jane M; Breidt, Frederick, E-mail: bourham@ncsu.edu, E-mail: mmccord@ncsu.edu, E-mail: xiangwu_zhang@ncsu.edu [Department of Food Science, North Carolina Agricultural Research Service, North Carolina State University, Raleigh, NC 27695-7624 (United States)
2011-10-15
ZnO/Nylon 6 nanofiber mats were prepared by an electrospinning-electrospraying hybrid process in which ZnO nanoparticles were dispersed on the surface of Nylon 6 nanofibers without becoming completely embedded. The prepared ZnO/Nylon 6 nanofiber mats were evaluated for their abilities to kill bacteria or inhibit their growth and to catalytically detoxify chemicals. Results showed that these ZnO/Nylon 6 nanofiber mats had excellent antibacterial efficiency (99.99%) against both the Gram-negative Escherichia coli and Gram-positive Bacillus cereus bacteria. In addition, they exhibited good detoxifying efficiency (95%) against paraoxon, a simulant of highly toxic chemicals. ZnO/Nylon 6 nanofiber mats were also deposited onto nylon/cotton woven fabrics and the nanofiber mats did not significantly affect the moisture vapor transmission rates and air permeability values of the fabrics. Therefore, ZnO/Nylon 6 nanofiber mats prepared by the electrospinning-electrospraying hybrid process are promising material candidates for protective applications.
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Sewage, green algal mats anchored by lugworms, and the effects on Turbellaria and small Polychaeta
Reise, Karsten
1983-06-01
On sandy tidal flats at the Island of Sylt (North Sea) ephemeral mats of green algae covered wide areas in the vicinity of sewage outflows. Algae became anchored in the feeding funnels of lugworms ( Arenicola marina) and thus were able to resist displacement by tidal currents. Below the algal mats anoxic conditions extend to the sediment surface. After about one month a rough sea removed all algae. Polychaetes endured this short-term environmental deterioration, while the more sensitive Turbellaria decreased in abundance and species richness. Diatom-feeders were affected most, predators to a medium extent, and bacteria-feeders the least affected. Rare and very abundant species were more affected than moderately abundant ones. None of the turbellarian species increased in abundance and none colonized the algal mats above the sediment. In a semicontrolled experiment with daily hand-removal of drift algae from a 100-m2 plot within an extensive field of algal mats, this cleaned "island" served as a refuge to Turbellaria escaping from their algal covered habitat. Here abundance doubled relative to initial conditions and was 5-times higher than below algal mats.
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Vargas, Hugo E; Laskus, Tomasz; Radkowski, Marek; Wilkinson, Jeff; Balan, Vijay; Douglas, David D; Harrison, M Edwyn; Mulligan, David C; Olden, Kevin; Adair, Debra; Rakela, Jorge
2002-11-01
Patients with chronic hepatitis C frequently report tiredness, easy fatigability, and depression. The aim of this study is to determine whether hepatitis C virus (HCV) replication could be found in brain tissue in patients with hepatitis C and depression. We report two patients with recurrent hepatitis C after liver transplantation who also developed severe depression. One patient died of multiorgan failure and the other, septicemia caused by Staphylococcus aureussis. Both patients had evidence of severe hepatitis C recurrence with features of cholestatic fibrosing hepatitis. We were able to study samples of their central nervous system obtained at autopsy for evidence of HCV replication. The presence of HCV RNA-negative strand, which is the viral replicative form, was determined by strand-specific Tth-based reverse-transcriptase polymerase chain reaction. Viral sequences were compared by means of single-strand conformation polymorphism and direct sequencing. HCV RNA-negative strands were found in subcortical white matter from one patient and cerebral cortex from the other patient. HCV RNA-negative strands amplified from brain tissue differed by several nucleotide substitutions from serum consensus sequences in the 5' untranslated region. These findings support the concept of HCV neuroinvasion, and we speculate that it may provide a biological substrate to neuropsychiatric disorders observed in patients with chronic hepatitis C. The exact lineage of cells permissive for HCV replication and the possible interaction between viral replication and cerebral function that may lead to depression remain to be elucidated.
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Directory of Open Access Journals (Sweden)
Salles José Maria
2003-01-01
Full Text Available Amebiasis can be considered the most aggressive disease of the human intestine, responsible in its invasive form for clinical syndromes, ranging from the classic dysentery of acute colitis to extra-intestinal disease, with emphasis on hepatic amebiasis, unsuitably named amebic liver abscess. Found worldwide, with a high incidence in India, tropical regions of Africa, Mexico and other areas of Central America, it has been frequently reported in Amazonia. The trophozoite reaches the liver through the portal system, provoking enzymatic focal necrosis of hepatocytes and multiple micro-abscesses that coalesce to develop a single lesion whose central cavity contains a homogeneous thick liquid, with typically reddish brown and yellow color similar to "anchovy paste". Right upper quadrant pain, fever and hepatomegaly are the predominant symptoms of hepatic amebiasis. Jaundice is reported in cases with multiple lesions or a very large abscess, and it affects the prognosis adversely. Besides chest radiography, ultrasonography and computerized tomography have brought remarkable contributions to the diagnosis of hepatic abscesses. The conclusive diagnosis is made however by the finding of Entamoeba histolytica trophozoites in the pus and by the detection of serum antibodies to the amoeba. During the evolution of hepatic amebiasis, in spite of the availability of highly effective drugs, some important complications may occur with regularity and are a result of local perforation with extension into the pleural and pericardium cavities, causing pulmonary abscesses and purulent pericarditis, respectively The ruptures into the abdominal cavity may lead to subphrenic abscesses and peritonitis. The treatment of hepatic amebiasis is made by medical therapy, with metronidazole as the initial drug, followed by a luminal amebicide. In patients with large abscesses, showing signs of imminent rupture, and especially those who do not respond to medical treatment, a
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Directory of Open Access Journals (Sweden)
José Maria Salles
Full Text Available Amebiasis can be considered the most aggressive disease of the human intestine, responsible in its invasive form for clinical syndromes, ranging from the classic dysentery of acute colitis to extra-intestinal disease, with emphasis on hepatic amebiasis, unsuitably named amebic liver abscess. Found worldwide, with a high incidence in India, tropical regions of Africa, Mexico and other areas of Central America, it has been frequently reported in Amazonia. The trophozoite reaches the liver through the portal system, provoking enzymatic focal necrosis of hepatocytes and multiple micro-abscesses that coalesce to develop a single lesion whose central cavity contains a homogeneous thick liquid, with typically reddish brown and yellow color similar to "anchovy paste". Right upper quadrant pain, fever and hepatomegaly are the predominant symptoms of hepatic amebiasis. Jaundice is reported in cases with multiple lesions or a very large abscess, and it affects the prognosis adversely. Besides chest radiography, ultrasonography and computerized tomography have brought remarkable contributions to the diagnosis of hepatic abscesses. The conclusive diagnosis is made however by the finding of Entamoeba histolytica trophozoites in the pus and by the detection of serum antibodies to the amoeba. During the evolution of hepatic amebiasis, in spite of the availability of highly effective drugs, some important complications may occur with regularity and are a result of local perforation with extension into the pleural and pericardium cavities, causing pulmonary abscesses and purulent pericarditis, respectively The ruptures into the abdominal cavity may lead to subphrenic abscesses and peritonitis. The treatment of hepatic amebiasis is made by medical therapy, with metronidazole as the initial drug, followed by a luminal amebicide. In patients with large abscesses, showing signs of imminent rupture, and especially those who do not respond to medical treatment, a
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Oki, T.; Pokhrel, Y. N.; Yeh, P. J.; Koirala, S.; Kanae, S.; Hanasaki, N.
2011-12-01
The real hydrological cycles on the Earth are not natural anymore. Global hydrological model simulations of the water cycle and available water resources should have an ability to consider the effects of human interventions on hydrological cycles. Anthropogenic activity modules (Hanasaki et al., 2008), such as reservoir operation, crop growth and water demand in crop lands, and environmental flows, were incorporated into a land surface model called MATSIRO (Takata et al., 2003), to form a new model, MAT-HI (Pokhrel et al., 2011). Total terrestrial water storages (TWS) in large river basins were estimated using the new model by off-line simulation, and compared with the TWS observed by GRACE for 2002-2007. The results showed MAT-HI has an advantage estimating TWS particularly in arid river basins compared with H08 (Hanasaki et al., 2008). MAT-HI was further coupled with a module representing the ground water level fluctuations (Yeh et al., 2005), and consists a new land surface scheme HiGW-MAT (Human Intervention and Ground Water coupled MATSIRO). HiGW-MAT is also associated with a scheme tracing the origin and flow path with the consideration on the sources of water withdrawal from stream flow, medium-size reservoirs and nonrenewable groundwater in addition to precipitation to croplands enabled the assessment of the origin of water producing major crops as Hanasaki et al. (2010). Areas highly dependent on nonrenewable groundwater are detected in the Pakistan, Bangladesh, western part of India, north and western parts of China, some regions in the Arabian Peninsula and the western part of the United States through Mexico. Cumulative nonrenewable groundwater withdrawals estimated by the model are corresponding fairly well with the country statistics of total groundwater withdrawals. Ground water table depletions in large aquifers in US estimated by HiGW-MAT were compared with in-situ observational data, and the correspondences are very good. Mean global exploitation
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Mutimer, D; Shaw, J; Neuberger, J; Skidmore, S; Martin, B; Hubscher, S; McMaster, P; Elias, E
1995-01-01
Sporadic non-A, non-B hepatitis is the most common indication for liver transplantation in patients presenting with fulminant and subacute liver failure. This study used serological, histological, and molecular biological techniques to examine specimens from 23 consecutive patients transplanted for sporadic non-A, non-B hepatitis. No evidence was found of hepatitis C virus, hepatitis E virus, or 'cryptic' hepatitis B virus infection.
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Wu, Keke; Zhang, Xiazhi; Yang, Wufeng; Liu, Xiaoyan; Jiao, Yanpeng; Zhou, Changren
2016-12-01
Electrospun poly(L-lactic acid) (PLLA) nanofiber mats were successfully modified by deposition of multilayers with chitosan (CS), heparin (Hep) and graphene oxide (GO) through electrostatic layer-by-layer (LBL) self-assembly method. In this study, the surface properties of PLLA nanofiber mats before and after modification were investigated via scanning electron microscope (SEM), atomic force microscopy (AFM), attenuated total reflectance fourier transformation infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and water contact angle measurement. In addition, the cytocompatibility of the modified PLLA nanofiber mats were investigated by testing endothelial cells compatibility, including cell attachment, cell proliferation and cell cycle. The results revealed that the surfaces of modified PLLA nanofiber mats become much rougher, stifiness and the hydrophilicity of the LBL modified PLLA nanofiber mats were improved compared to original PLLA one. Moreover, the modified PLLA nanofiber mats had promoted the endothelial cells viability attachment significantly. Besides, we studied the PLLA nanofiber mats on the expression of necrosis factor (TNF-α), interleukine-1β (IL-1β), monocyte chemoattractant protein-1 (MCP-1) and vascular cell adhesion molecule-1 (VCAM-1) in endothelial cells. The results showed that modified PLLA nanofiber mats had inhibited the inflammatory response to some extent.
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The Management of Chronic Viral Hepatitis: A Canadian Consensus Conference 2004
Directory of Open Access Journals (Sweden)
Morris Sherman
2004-01-01
Full Text Available Several government and nongovernment organizations held a consensus conference on the management of acute and chronic viral hepatitis to update previous management recommendations. The conference became necessary because of the introduction of new forms of therapy for both hepatitis B and hepatitis C. The conference issued recommendations on the investigation and management of chronic hepatitis B, including the use of lamivudine, adefovir and interferon. The treatment of hepatitis B in several special situations was also discussed. There were also recommendations on the investigation and treatment of chronic hepatitis C and hepatitis C-HIV coinfection. In addition, the document makes some recommendations about the provision of services by provincial governments to facilitate the delivery of care to patients with hepatitis virus infection. The present document is meant to be used by practitioners and other health care providers, including public health staff and others not directly involved in patient care.
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... most common types of viral hepatitis. What Is Hepatitis A? For kids, hep A is the most common ... they recover, it does not come back. Can Hepatitis A Be Prevented? The following will help keep people ...
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Sagnelli, Evangelista; Coppola, Nicola; Pisaturo, Mariantonietta; Pisapia, Raffaella; Onofrio, Mirella; Sagnelli, Caterina; Catuogno, Antonio; Scolastico, Carlo; Piccinino, Felice; Filippini, Pietro
2006-06-01
We evaluated the clinical and virological characteristics of hepatitis A virus infection in persons concomitantly infected with hepatitis B virus (HBV) or hepatitis C virus (HCV). We enrolled 21 patients with acute hepatitis A and chronic hepatitis with no sign of liver cirrhosis, 13 patients who were positive for hepatitis B surface antigen (case B group), 8 patients who were anti-HCV positive (case C group), and 21 patients with acute hepatitis A without a preexisting liver disease (control A group). Two control groups of patients with chronic hepatitis B (control B group) or C (control C group) were also chosen. All control groups were pair-matched by age and sex with the corresponding case group. Fulminant hepatitis A was never observed, and hepatitis A had a severe course in 1 patient in the case B group and in 1 patient in the control A group. Both patients recovered. On admission, HBV DNA was detected in 1 patient in the case B group (7.7%) and in 13 patients (50%) in the control B group; HCV RNA was found in no patient in the case C group and in 16 patients (81.2%) in the control C group. Of 9 patients in the case B group who were followed up for 6 months, 3 became negative for hepatitis B surface antigen and positive for hepatitis B surface antibody, 2 remained positive for hepatitis B surface antigen and negative for HBV DNA, and 4 became positive for HBV DNA with a low viral load [corrected] Of 6 patients in the case C group who were followed up for 6 months, 3 remained negative for HCV RNA, and 3 had persistently low viral loads. Concomitant hepatitis A was always self-limited, associated with a marked inhibition of HBV and HCV genomes, and possibly had a good prognosis for the underlying chronic hepatitis.
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Tu, Hu; Huang, Mengtian; Yi, Yang; Li, Zhenshun; Zhan, Yingfei; Chen, Jiajia; Wu, Yang; Shi, Xiaowen; Deng, Hongbing; Du, Yumin
2017-12-01
Chitosan (CS), as a kind of well characterized biopolymer, has been used for heavy metal adsorption due to its low cost and high efficacy. However, when used directly, chitosan particles had small surface area and weak mechanical strength which is unfavorable to metal adsorption and reused. Besides, it cannot be easily recycled that may cause a secondary pollution. In this paper, CS and layered silicate rectorite (REC) were fully mixed and the mixtures were subsequently electrosprayed nano-sized spheres, which were immobilized on the surface of electrospun polystyrene (PS) mats for metal adsorption. The morphology analysis taken from SEM confirmed that CS-REC nanospheres were loaded on the surface of PS fibrous mats. Small Angle X-ray diffraction patterns showed that the interlayer distance of REC in composite mats was enlarged by the intercalation of CS chains; such structure meant bigger surface area which was helpful for metal adsorption. The data of contact angle implied that PS mats coated with CS-REC nanospheres exhibited better hydrophilicity than PS mats, which was conductive to adsorption rate. Besides, the copper ions adsorption of composite mats was tested at different conditions including the adsorption time, the initial pH and the initial concentration of copper ion. The results demonstrated that PS mats coated with CS-REC nanospheres had the adsorption capacity up to 134 mg/g. In addition, the addition of REC containing Ca2+ could also improve the metal adsorption because of cation exchange. The desorption assay indicated that PS mats immobilized with CS and CS-REC still kept high adsorption ability which retained 74% and 78% after three adsorption-desorption cycles.
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Nanofiber mat spinal cord dressing-released glutamate impairs blood-spinal cord barrier
Directory of Open Access Journals (Sweden)
Dorota Sulejczak
2016-12-01
Full Text Available An excessive glutamate level can result in excitotoxic damage and death of central nervous system (CNS cells, and is involved in the pathogenesis of many CNS diseases. It may also be related to a failure of the blood-spinal cord barrier (BSCB. This study was aimed at examining the effects of extended administration of monosodium glutamate on the BSCB and spinal cord cells in adult male Wistar rats. The glutamate was delivered by subarachnoidal application of glutamate-carrying electrospun nanofiber mat dressing at the lumbar enlargement level. Half of the rats with the glutamate-loaded mat application were treated systemically with the histone deacetylase inhibitor valproic acid. A group of intact rats and a rat group with subarachnoidal application of an ‘empty’ (i.e., carrying no glutamate nanofiber mat dressing served as controls. All the rats were euthanized three weeks later and lumbar fragments of their spinal cords were harvested for histological, immunohistochemical and ultrastructural studies. The samples from controls revealed normal parenchyma and BSCB morphology, whereas those from rats with the glutamate-loaded nanofiber mat dressing showed many intraparenchymal microhemorrhages of variable sizes. The capillaries in the vicinity of the glutamate-carrying dressing (in the meninges and white matter alike were edematous and leaky, and their endothelial cells showed degenerative changes: extensive swelling, enhanced vacuolization and the presence of vascular intraluminal projections. However, endothelial tight junctions were generally well preserved. Some endothelial cells were dying by necrosis or apoptosis. The adjacent parenchyma showed astrogliosis with astrocytic hypertrophy and swelling of perivascular astrocytic feet. Neurons in the parenchyma revealed multiple symptoms of degeneration, including, inter alia, perikaryal, dendritic and axonal swelling, and destruction of organelles. All the damage symptoms were slightly less
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Ogholikhan, Sina; Schwarz, Kathleen B.
2016-01-01
Viral hepatitis is a serious health problem all over the world. However, the reduction of the morbidity and mortality due to vaccinations against hepatitis A and hepatitis B has been a major component in the overall reduction in vaccine preventable diseases. We will discuss the epidemiology, vaccine development, and post-vaccination effects of the hepatitis A and B virus. In addition, we discuss attempts to provide hepatitis D vaccine for the 350 million individuals infected with hepatitis B ...
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Directory of Open Access Journals (Sweden)
Sina Ogholikhan
2016-03-01
Full Text Available Viral hepatitis is a serious health problem all over the world. However, the reduction of the morbidity and mortality due to vaccinations against hepatitis A and hepatitis B has been a major component in the overall reduction in vaccine preventable diseases. We will discuss the epidemiology, vaccine development, and post-vaccination effects of the hepatitis A and B virus. In addition, we discuss attempts to provide hepatitis D vaccine for the 350 million individuals infected with hepatitis B globally. Given the lack of a hepatitis C vaccine, the many challenges facing the production of a hepatitis C vaccine will be shown, along with current and former vaccination trials. As there is no current FDA-approved hepatitis E vaccine, we will present vaccination data that is available in the rest of the world. Finally, we will discuss the existing challenges and questions facing future endeavors for each of the hepatitis viruses, with efforts continuing to focus on dramatically reducing the morbidity and mortality associated with these serious infections of the liver.
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Ogholikhan, Sina; Schwarz, Kathleen B.
2016-01-01
Viral hepatitis is a serious health problem all over the world. However, the reduction of the morbidity and mortality due to vaccinations against hepatitis A and hepatitis B has been a major component in the overall reduction in vaccine preventable diseases. We will discuss the epidemiology, vaccine development, and post-vaccination effects of the hepatitis A and B virus. In addition, we discuss attempts to provide hepatitis D vaccine for the 350 million individuals infected with hepatitis B globally. Given the lack of a hepatitis C vaccine, the many challenges facing the production of a hepatitis C vaccine will be shown, along with current and former vaccination trials. As there is no current FDA-approved hepatitis E vaccine, we will present vaccination data that is available in the rest of the world. Finally, we will discuss the existing challenges and questions facing future endeavors for each of the hepatitis viruses, with efforts continuing to focus on dramatically reducing the morbidity and mortality associated with these serious infections of the liver. PMID:26978406
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Primary hepatic artery embolization in pediatric blunt hepatic trauma.
Ong, Caroline C P; Toh, Luke; Lo, Richard H G; Yap, Te-Lu; Narasimhan, Kannan
2012-12-01
Non-operative management of isolated blunt hepatic trauma is recommended except when hemodynamic instability requires immediate laparotomy. Hepatic artery angioembolization is increasingly used for hepatic injuries with ongoing bleeding as demonstrated by contrast extravasation on the CT scan. It is used primarily or after laparotomy to control ongoing hemorrhage. Hepatic angioembolization as part of multimodality management of hepatic trauma is reported mainly in adults, with few pediatric case reports. We describe our institution experience with primary pediatric hepatic angioembolization and review the literature with regard to indications and complications. Two cases (3 and 8 years old), with high-grade blunt hepatic injuries with contrast extravasation on the CT scan were successfully managed by emergency primary hepatic angioembolization with minimal morbidity and avoided laparotomy. To date, the only reports of pediatric hepatic angioembolization for trauma are 5 cases for acute bleeding and 15 delayed cases for pseudoaneurysm. The role of hepatic angioembolization in the presence of an arterial blush on CT in adults is accepted, but contested in a pediatric series, despite higher transfusion rate and mortality rate. We propose that hepatic angioembolization should be considered adjunct treatment, in lieu of, or in addition to emergency laparotomy for hemostasis in pediatric blunt hepatic injury. Copyright © 2012 Elsevier Inc. All rights reserved.
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Feature Hepatitis: Hepatitis Symptoms, Diagnosis, Treatment & Prevention
... Navigation Bar Home Current Issue Past Issues Feature Hepatitis Hepatitis: Symptoms, Diagnosis, Treatment & Prevention Past Issues / Spring 2009 ... No appetite Fever Headaches Diagnosis To check for hepatitis viruses, your doctor will test your blood. You ...
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Mackey, T. J.; Leidman, S. Z.; Allen, B.; Hawes, I.; Lawrence, J.; Jungblut, A. D.; Krusor, M.; Coleman, L.; Sumner, D. Y.
2015-12-01
Structure from Motion (SFM) techniques can provide quantitative morphological documentation of otherwise inaccessible benthic ecosystems such as microbial mats in Lake Joyce, a perennially ice-covered lake of the Antarctic McMurdo Dry Valleys (MDV). Microbial mats are a key ecosystem of MDV lakes, and diverse mat morphologies like pinnacles emerge from interactions among microbial behavior, mineralization, and environmental conditions. Environmental gradients can be isolated to test mat growth models, but assessment of mat morphology along these gradients is complicated by their inaccessibility: the Lake Joyce ice cover is 4-5 m thick, water depths containing diverse pinnacle morphologies are 9-14 m, and relevant mat features are cm-scale. In order to map mat pinnacle morphology in different sedimentary settings, we deployed drop cameras (SeaViewer and GoPro) through 29 GPS referenced drill holes clustered into six stations along a transect spanning 880 m. Once under the ice cover, a boom containing a second GoPro camera was unfurled and rotated to collect oblique images of the benthic mats within dm of the mat-water interface. This setup allowed imaging from all sides over a ~1.5 m diameter area of the lake bottom. Underwater lens parameters were determined for each camera in Agisoft Lens; images were reconstructed and oriented in space with the SFM software Agisoft Photoscan, using the drop camera axis of rotation as up. The reconstructions were compared to downward facing images to assess accuracy, and similar images of an object with known geometry provided a test for expected error in reconstructions. Downward facing images identify decreasing pinnacle abundance in higher sedimentation settings, and quantitative measurements of 3D reconstructions in KeckCAVES LidarViewer supplement these mat morphological facies with measurements of pinnacle height and orientation. Reconstructions also help isolate confounding variables for mat facies trends with measurements
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... Home A-Z Health Topics Viral hepatitis Viral hepatitis > A-Z Health Topics Viral hepatitis (PDF, 90 ... liver. Source: National Cancer Institute Learn more about hepatitis Watch a video. Learn who is at risk ...
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[Chronic active hepatitis: clinical, biochemical, and histopathologic correlation].
Subauste, M C
1989-01-01
A retrospective study over 26 female patients with chronic active hepatitis was made. The mean age was 39 years old, the mean length of illness of 8 months; 5 patients had positive markers for hepatitis B. Patients were selected with the grade of histological activity: 8 patients had a mild form from disease (2A) and 16 with a severe one (2B). The predominant group was 2B. Severe inflammatory infiltration was the hallmark and multiobulillar necrosis, bridging, eosinophils and hiperplasia of kuppfer cells were found only in this group. Clinical features range from hepatic manifestations to systemic ones. Chronic active hepatitis may present with cholestasis, but the latter is not always related with the grade of activity. Group 2B had elevated aminotransferases and a low concentration for protrobine.
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Meric, Dogus; Barbuto, Sara; Sheahan, Thomas C; Shine, James P; Alshawabkeh, Akram N
2014-01-01
This paper describes the results of a benchscale testing program to assess the efficacy of a reactive core mat (RCM) for short term isolation and partial remediation of contaminated, subaqueous sediments. The 1.25 cm thick RCM (with a core reactive material such as organoclay with filtering layers on top and bottom) is placed on the sediment, and approximately 7.5 - 10 cm of overlying soil is placed on the RCM for stability and protection. A set of experiments were conducted to measure the sorption characteristics of the mat core (organoclay) and sediment used in the experiments, and to determine the fate of semi-volatile organic contaminants and non-reactive tracers through the sediment and reactive mat. The experimental study was conducted on naphthalene-spiked Neponset River (Milton, MA) sediment. The results show nonlinear sorption behavior for organoclay, with sorption capacity increasing with increasing naphthalene concentration. Neponset River sediment showed a notably high sorption capacity, likely due to the relatively high organic carbon fraction (14%). The fate and transport experiments demonstrated the short term efficiency of the reactive mat to capture the contamination that is associated with the post-capping period during which the highest consolidation-induced advective flux occurs, driving solid particles, pore fluid and soluble contaminants toward the reactive mat. The goal of the mat placement is to provide a physical filtering and chemically reactive layer to isolate contamination from the overlying water column. An important finding is that because of the high sorption capacity of the Neponset River sediment, the physical filtering capability of the mat is as critical as its chemical reactive capacity.
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Original Article Studies on Prevalence and Risk Factors for Hepatitis ...
African Journals Online (AJOL)
2011-12-20
Dec 20, 2011 ... Risk factors such as blood transfusion was 32.0% among male ... females. Unfortunately, the prevalence of HBV appears high among the studied ... form of both acute and chronic viral hepatitis ... of expression for this disease, at this phase the .... Alcohol consumption .... Hepatitis B virus Infection in China.
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Thermodynamics and phase transformations: the selected works of Mats Hillert
International Nuclear Information System (INIS)
Agren, J.; Brechet, Y.; Hutchinson, Ch.; Purdy, G.
2006-01-01
For over half a century, Mats Hillert has contributed greatly to the science of materials. He is widely known and respected as an innovator and an educator, a scientist with an enormous breadth of interest and depth of insight. In acknowledgment of his many contributions, a conference was held in Stockholm in December 2004 to mark his eightieth birthday. This volume was conceived prior to, and publicly announced during the conference. The difficult choice of twenty-four papers from a publication list of more than three hundred was carried out in consultation with Mats. He also suggested or approved the scientists who would be invited to write a brief introduction to each paper. A brief reading of the topics of the selected papers and their introductions reveals something of their range and depth. Several early selections (for example, those on 'The Role of Interfacial Energy during Solid State Phase Transformations', and 'A Solid-Solution Model for Inhomogeneous Systems') contained seminal material that established Mats as a leading figure in the study of phase transformations in solids. Others established his presence in the areas of solidification and computational thermodynamics. A review of his full publication list shows that he has consistently built upon those early foundational papers, and maintained a dominant position in those fields. Although many of his contributions have been of a theoretical nature, he has always maintained a close contact with experiment, and indeed, he has designed numerous critical experiments. This volume represents a judicious sampling of Mats Hillert's extensive body of work; it is necessarily incomplete, but it is hoped and expected that it will prove useful to students of materials science and engineering at all levels, and that it will inspire the further study and appreciation of his many contributions. (authors)
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Microbial mat-induced sedimentary structures in siliciclastic sediments
Indian Academy of Sciences (India)
This paper addresses macroscopic signatures of microbial mat-related structures within the. 1.6Ga-old Chorhat Sandstone ... Sandstone differentiated in facies superposed one over the other and their respective structural assemblages (b). may be ..... within the classification of primary sedimentary struc- tures; J. Sed. Res.
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... B Entire Lesson Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For Veterans and the Public Veterans ... in their blood (sometimes referred to as the hepatitis B viral load) and an unusually high level of a ...
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Full Text Available ... A Hepatitis B Hepatitis C Intrahepatic Cholestasis of Pregnancy (ICP) Jaundice In Newborns Diseases of the Liver ... A Hepatitis B Hepatitis C Intrahepatic Cholestasis of Pregnancy (ICP) Jaundice In Newborns Diseases of the Liver ...
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... Home » Living with Hepatitis » Daily Living: Alcohol Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For ... heavy drinking, most heavy drinkers have developed cirrhosis. Hepatitis C and cirrhosis In general, someone with hepatitis ...
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... Public Home » Hepatitis C » Hepatitis C Treatment Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For ... Enter ZIP code here Enter ZIP code here Hepatitis C Treatment for Veterans and the Public Treatment ...
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Directory of Open Access Journals (Sweden)
Steven R. Ahrendt
2014-03-01
Full Text Available Atmospheric levels of carbon dioxide (CO2 are rising at an accelerated rate resulting in changes in the pH and carbonate chemistry of the world’s oceans. However, there is uncertainty regarding the impact these changing environmental conditions have on carbonate-depositing microbial communities. Here, we examine the effects of elevated CO2, three times that of current atmospheric levels, on the microbial diversity associated with lithifying microbial mats. Lithifying microbial mats are complex ecosystems that facilitate the trapping and binding of sediments, and/or the precipitation of calcium carbonate into organosedimentary structures known as microbialites. To examine the impact of rising CO2 and resulting shifts in pH on lithifying microbial mats, we constructed growth chambers that could continually manipulate and monitor the mat environment. The microbial diversity of the various treatments was compared using 16S rRNA gene pyrosequencing. The results indicated that elevated CO2 levels during the six month exposure did not profoundly alter the microbial diversity, community structure, or carbonate precipitation in the microbial mats; however some key taxa, such as the sulfate-reducing bacteria Deltasulfobacterales, were enriched. These results suggest that some carbonate depositing ecosystems, such as the microbialites, may be more resilient to anthropogenic-induced environmental change than previously thought.
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The effect Mat Pilates practice on muscle mass in elderly women
Directory of Open Access Journals (Sweden)
Leliz Cristina Sampaio Queiroz
2016-01-01
Full Text Available Objective: to verify that the Mat Pilates practice increases muscle mass in elderly women. Methods: quasi-experimental study with primary data collection and with a convenience sample. The muscle mass of 43 elderly was evaluated for 11 weeks, by calculating the arm muscle area, before and after the intervention. Results:statistically significant difference was observed (p<0.002 between the average value of the arm muscle area, before (35.56cm2 and after the exercises (42.72cm2. Conclusion: mat Pilates program generates positive effect on increasing the muscle mass of elderly.
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Contradicción, coherencia y compromiso: Matías Usero Torrente
Directory of Open Access Journals (Sweden)
Tezanos Gandarillas, Marisa
2001-06-01
Full Text Available The current article studies the figure of Matías Usero Torrente. His thought is considered by the author as a preceding of the principals ideas that emphasized about the relations between State and Society during the sixties in Spain.
En el presente artículo se analiza la figura de Matías Usero Torrente. Su pensamiento es considerado por la autora del estudio como antecesor de las principales ideas que sobre las relaciones de la Iglesia con el Estado y la Sociedad cristalizaron en la década de los 60 en España. -
Radha Krishna, Yellapu; Saraswat, Vivek Anand; Das, Khaunish; Himanshu, Goel; Yachha, Surender Kumar; Aggarwal, Rakesh; Choudhuri, Gour
2009-03-01
Acute hepatitis A and E are recognized triggers of hepatic decompensation in patients with cirrhosis, particularly from the Indian subcontinent. However, the resulting acute-on-chronic liver failure (ACLF) has not been well characterized and no large studies are available. Our study aimed to evaluate the clinical profile and predictors of 3-month mortality in patients with this distinctive form of liver failure. ACLF was diagnosed in patients with acute hepatitis A or E [abrupt rise in serum bilirubin and/or alanine aminotransferase with positive immunoglobulin M anti-hepatitis A virus (HAV)/anti-hepatitis E virus (HEV)] presenting with clinical evidence of liver failure (significant ascites and/or hepatic encephalopathy) and clinical, biochemical, endoscopic (oesophageal varices at least grade II in size), ultrasonographical (presence of nodular irregular liver with porto-systemic collaterals) or histological evidence of cirrhosis. Clinical and laboratory profile were evaluated, predictors of 3-month mortality were determined using univariate and multivariate logistic regression and a prognostic model was constructed. Receiver-operating curves were plotted to measure performance of the present prognostic model, model for end-stage liver disease (MELD) score and Child-Turcotte-Pugh (CTP) score. ACLF occurred in 121 (3.75%) of 3220 patients (mean age 36.3+/-18.0 years; M:F 85:36) with liver cirrhosis admitted from January 2000 to June 2006. It was due to HEV in 80 (61.1%), HAV in 33 (27.2%) and both in 8 (6.1%). The underlying liver cirrhosis was due to HBV (37), alcohol (17), Wilson's disease (8), HCV (5), autoimmune (6), Budd-Chiari syndrome (2), haemochromatosis (2) and was cryptogenic in the rest (42). Common presentations were jaundice (100%), ascites (78%) and hepatic encephalopathy (55%). Mean (SD) CTP score was 11.4+/-1.6 and mean MELD score was 28.6+/-9.06. Three-month mortality was 54 (44.6%). Complications seen were sepsis in 42 (31.8%), renal failure in
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Pagaling, Eulyn; Grant, William D; Cowan, Don A; Jones, Brian E; Ma, Yanhe; Ventosa, Antonio; Heaphy, Shaun
2012-07-01
We investigated the bacterial and archaeal diversity in two hot spring microbial mats from the geothermal region of Tengchong in the Yunnan Province, China, using direct molecular analyses. The Langpu (LP) laminated mat was found by the side of a boiling pool with temperature of 60-65 °C and a pH of 8.5, while the Tengchong (TC) streamer mat consisted of white streamers in a slightly acidic (pH 6.5) hot pool outflow with a temperature of 72 °C. Four 16S rRNA gene clone libraries were constructed and restriction enzyme analysis of the inserts was used to identify unique sequences and clone frequencies. From almost 200 clones screened, 55 unique sequences were retrieved. Phylogenetic analysis showed that the LP mat consisted of a diverse bacterial population [Cyanobacteria, Chloroflexi, Chlorobia, Nitrospirae, 'Deinococcus-Thermus', Proteobacteria (alpha, beta and delta subdivisions), Firmicutes, Bacteroidetes and Actinobacteria], while the archaeal population was dominated by methanogenic Euryarchaeota and Crenarchaeota. In contrast, the TC streamer mat consisted of a bacterial population dominated by Aquificae, while the archaeal population also contained Korarchaeota as well as Crenarchaeota and methanogenic Euryarchaeota. These mats harboured clone sequences affiliated to unidentified lineages, suggesting that they are a potential source for discovering novel bacteria and archaea.
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Occult hepatitis B among Iranian hepatitis C patients
Directory of Open Access Journals (Sweden)
Ahmad shavakhi
2009-02-01
Full Text Available
- BACKGROUND: Occult hepatitis B is defined as presence of HBV DNA in tissue or serum without hepatitis B surface antigen. The aim of this study is to determine frequency of occult hepatitis B among hepatitis C patients in Tehran and compare the route of transmission and liver enzymes between positive and negative HBV DNA patients.
- METHODS: In a cross sectional study, serum of 103 hepatitis C cases (79.6% men and 20.4% women were analyzed for s, x and core genes via a nested polymerase chain reaction technique.
- RESULTS: HBV DNA was detectable in serum of 20 patients (19.4%. No significant difference in age, sex and route of transmission were seen in HBV DNA positive and negative patients. In HBV DNA positive and negative groups, mean of AST was 73, 47 (p < 0.05 and mean of ALT was 76 and 36 respectively (p < 0.05.
- CONCLUSION: Occult hepatitis B was observed in a considerable number of hepatitis C patients in Tehran. It was associated with elevation in liver enzyme but was not related to route of transmission.
- KEY WORD: Occult hepatitis B, hepatitis C, cirrhosis.
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Donselaar, van R.; Chen, W.
2011-01-01
In this paper, we present a design of a smart textile pressure mat to study the pressure distribution with multiple foam material configurations for neonatal monitoring at Neonatal Intensive Care Units (NICU). A smart textile mat with 64 pressure sensors has been developed including software at the
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Matting of Hair Due to Halo-egg Shampoo
Directory of Open Access Journals (Sweden)
Z M Mani
1983-01-01
Full Text Available A case of hair matting in an 18 year old female is reported. The hair got densely entangled immediately after washing the hair with ′Halo Egg′ shampoo. The hair was disentangled completely after prolonged dipping of the hair in arachis oil frr 5 days.
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Diversity of nitrogen-fixing bacteria in cyanobacterial mats
Severin, I.; Acinas, S.G.; Stal, L.J.
2010-01-01
The structure of the microbial community and the diversity of the functional gene for dinitrogenase reductase and its transcripts were investigated by analyzing >1400 16S rRNA gene and nifH sequences from two microbial mats situated in the intertidal zone of the Dutch barrier island Schiermonnikoog.
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The Use of Maltodextrin Matrices to Control the Release of Minerals from Fortified Maté
Directory of Open Access Journals (Sweden)
Miguel E. Schmalko
2012-04-01
Full Text Available Normal 0 false false false EN-US X-NONE X-NONE The aim of this research was to study the sensorial acceptance of a fortified food containing different minerals (calcium, magnesium and iron and to determine the actual quantities present (bioaccessibility when extracted in maté. A sensorial analysis was performed to compare sensorial quality of fortified and non-fortified maté. Although panelists identified differences between the fortified and non-fortified maté, only 3% of them commented on an unpleasant flavor. Sequential extraction assays were performed simulating maté consumption under laboratory conditions. Profile concentration diminished sharply after the second extraction. Magnesium was found to be completely extracted in the first 500 mL. Calcium and Iron were extracted in a very low percentage (29% and 25%, respectively. The outlet rate of the minerals was fitted to two models, and a good fitness (p < 0:001 in all cases was obtained.
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Marine Microbial Mats and the Search for Evidence of Life in Deep Time and Space
Des Marais, David J.
2011-01-01
Cyanobacterial mats in extensive seawater evaporation ponds at Guerrero Negro, Baja California, Mexico, have been excellent subjects for microbial ecology research. The studies reviewed here have documented the steep and rapidly changing environmental gradients experienced by mat microorganisms and the very high rates of biogeochemical processes that they maintained. Recent genetic studies have revealed an enormous diversity of bacteria as well as the spatial distribution of Bacteria, Archaea and Eukarya. These findings, together with emerging insights into the intimate interactions between these diverse populations, have contributed substantially to our understanding of the origins, environmental impacts, and biosignatures of photosynthetic microbial mats. The biosignatures (preservable cells, sedimentary fabrics, organic compounds, minerals, stable isotope patterns, etc.) potentially can serve as indicators of past life on early Earth. They also can inform our search for evidence of any life on Mars. Mars exploration has revealed evidence of evaporite deposits and thermal spring deposits; similar deposits on Earth once hosted ancient microbial mat ecosystems.
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International Nuclear Information System (INIS)
Merrick, H.W.; Dobelbower, R.R.; Ringleint, J.F.; Skeel, R.T.
1986-01-01
Renewed interest in hepatic artery infusion has been stimulated by the development of a totally implantable pump which eliminates many of the problems encountered by the external pumps and catheters. As the potential benefit of hepatic artery infusion would be greater if either all gross disease were removed by prior resection, or alternatively, if non-resectable disease were irradiated in conjunction with hepatic artery infusion, the authors initiated a phase I-II trial to evaluate combined modality therapy
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Kozubal, Mark A; Romine, Margaret; Jennings, Ryan deM; Jay, Zack J; Tringe, Susannah G; Rusch, Doug B; Beam, Jacob P; McCue, Lee Ann; Inskeep, William P
2013-03-01
Geothermal systems in Yellowstone National Park (YNP) provide an outstanding opportunity to understand the origin and evolution of metabolic processes necessary for life in extreme environments including low pH, high temperature, low oxygen and elevated concentrations of reduced iron. Previous phylogenetic studies of acidic ferric iron mats from YNP have revealed considerable diversity of uncultivated and undescribed archaea. The goal of this study was to obtain replicate de novo genome assemblies for a dominant archaeal population inhabiting acidic iron-oxide mats in YNP. Detailed analysis of conserved ribosomal and informational processing genes indicates that the replicate assemblies represent a new candidate phylum within the domain Archaea referred to here as 'Geoarchaeota' or 'novel archaeal group 1 (NAG1)'. The NAG1 organisms contain pathways necessary for the catabolism of peptides and complex carbohydrates as well as a bacterial-like Form I carbon monoxide dehydrogenase complex likely used for energy conservation. Moreover, this novel population contains genes involved in the metabolism of oxygen including a Type A heme copper oxidase, a bd-type terminal oxidase and a putative oxygen-sensing protoglobin. NAG1 has a variety of unique bacterial-like cofactor biosynthesis and transport genes and a Type3-like CRISPR system. Discovery of NAG1 is critical to our understanding of microbial community structure and function in extant thermophilic iron-oxide mats of YNP, and will provide insight regarding the evolution of Archaea in early Earth environments that may have important analogs active in YNP today.
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Energy Technology Data Exchange (ETDEWEB)
Kozubal, Mark; Romine, Margaret F.; Jennings, Ryan; Jay, Z.; Tringe, Susannah G.; Rusch, Douglas B.; Beam, Jake; McCue, Lee Ann; Inskeep, William P.
2013-03-01
Geothermal systems in Yellowstone National Park (YNP) provide an outstanding opportunity to understand the origin and evolution of metabolic processes necessary for life in extreme environments including low pH, high temperature, low oxygen and elevated concentrations of reduced iron. Previous phylogenetic studies of acidic ferric iron mats from YNP have revealed considerable diversity of uncultivated and undescribed archaea. The goal of this study was to obtain replicate de novo genome assemblies for a dominant archaeal population inhabiting acidic iron oxide mats in YNP. Detailed analysis of conserved ribosomal and informational processing genes indicate that the replicate assemblies represent a new phylum-level lineage referred to here as 'novel archaeal group 1 (NAG1)'. The NAG1 organisms contain pathways necessary for the catabolism of peptides and complex carbohydrates as well as a bacterial-like Form I CO dehydrogenase complex likely used for energy conservation. Moreover, this novel population contains genes involved in metabolism of oxygen including a Type A heme copper oxidase, a bd-type terminal oxidase and a putative oxygen sensing protoglobin. NAG1 has a variety of unique bacterial-like cofactor biosynthesis and transport genes and a Type3-like CRISPR system. Discovery of NAG1 is critical to our understanding of microbial community structure and function in extant thermophilic iron mats of YNP, and will provide insight regarding the evolution of Archaea in early Earth environments that may have important analogues active in YNP today.
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Perdhana, S. A. P.; Susilo, R. S. B.; Arifin; Redhono, D.; Sumandjar, T.
2018-03-01
Leptospirosis is a potentially fatal zoonosis that is endemic in many tropical regions and causes large epidemics after heavy rainfall and flooding. Severe disease is estimated 5–15% of all human infections. Its mortality rate is 5-40%. MAT, isolation of the organism, or leptospiral DNA in PCR are used to confirm Leptospirosis. This cross-sectional analytic study recruited 26 hospitalized leptospirosis patients admitted to Dr. Moewardi Hospital Surakarta. The diagnosis was based on clinical, laboratory and epidemiological findings. The onset of the disease was the date when the first symptom started, and the end of the analysis was the date when the patient died or discharged. Modified Faine’s score ≥ 25 tend to die (45.5%) while modified Faine’s score 20 – 24 tend to heal (60%) (OR 1.250; CI 0.259-6.029; p=1.0). Seropositive IgM predicts mortality 7.8 times higher than seronegative IgM (OR 7.800; CI 1.162-52.353; p=0.038). MAT positive predict mortality 10.667 times higher than MAT negative (OR 10.667; CI 1.705-66.720; p=0.015). Clinical manifestation, MAT, and serologic marker are all correlated with mortality in Leptospirosis. However, statistically, clinical manifestation has an insignificant correlation.
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Impacts of Canada's minimum age for tobacco sales (MATS) laws on youth smoking behaviour, 2000-2014.
Callaghan, Russell Clarence; Sanches, Marcos; Gatley, Jodi; Cunningham, James K; Chaiton, Michael Oliver; Schwartz, Robert; Bondy, Susan; Benny, Claire
2018-01-13
Recently, the US Institute of Medicine has proposed that raising the minimum age for tobacco purchasing/sales to 21 years would likely lead to reductions in smoking behavior among young people. Surprisingly few studies, however, have assessed the potential impacts of minimum-age tobacco restrictions on youth smoking. To estimate the impacts of Canadian minimum age for tobacco sales (MATS) laws on youth smoking behaviour. A regression-discontinuity design, using seven merged cycles of the Canadian Community Health Survey, 2000-2014. Survey respondents aged 14-22 years (n=98 320). Current Canadian MATS laws are 18 years in Alberta, Saskatchewan, Manitoba, Quebec, the Yukon and Northwest Territories, and 19 years of age in the rest of the country. Current, occasional and daily smoking status; smoking frequency and intensity; and average monthly cigarette consumption. In comparison to age groups slightly younger than the MATS, those just older had significant and abrupt increases immediately after the MATS in the prevalence of current smokers (absolute increase: 2.71%; 95% CI 0.70% to 4.80%; P=0.009) and daily smokers (absolute increase: 2.43%; 95% CI 0.74% to 4.12%; P=0.005). Average past-month cigarette consumption within age groups increased immediately following the MATS by 18% (95% CI 3% to 39%; P=0.02). There was no evidence of significant increases in smoking intensity for daily or occasional smokers after release from MATS restrictions. The study provides relevant evidence supporting the effectiveness of Canadian MATS laws for limiting smoking among tobacco-restricted youth. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
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Hepatitis B, interferon, and acne fulminans in a young girl
Directory of Open Access Journals (Sweden)
Sandeep Arora
2016-01-01
Full Text Available Acne fulminans (AF is a very rare severe form of acne seen in young males, characterized by a sudden and explosive onset of hemorrhagic pustules and ulceration on the trunk, systemic features in the form of fever, polyarthropathy, malaise, erythema nodosum and painful osteolytic bone involvement with leukocytosis, and an elevated erythrocyte sedimentation rate. Conventional treatment of AF includes corticosteroids or immunosuppressive agents for the initial phase followed by isotretinoin. Active hepatitis B infection with a high viral load precludes the administration of any immunosuppressive drugs. We present the case of an 18-year-old girl with a history of occasional acne who presented with AF of sudden onset following administration of interferon-alpha-2a for her recently detected hepatitis B infection. Management of hepatitis B was withheld in view of her general condition. The patient was managed with low dose isotretinoin with subsidence of lesions. AF in a young female precipitated by interferon and its management with isotretinoin in the presence of active hepatitis B infection make the case unique.
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HIV, hepatitis B, and hepatitis C in Zambia
Directory of Open Access Journals (Sweden)
Kenneth C Kapembwa
2011-01-01
Full Text Available Objectives : Epidemiologic data of HIV and viral hepatitis coinfection are needed in sub-Saharan Africa to guide health policy for hepatitis screening and optimized antiretroviral therapy (ART. Materials and Methods: We screened 323 HIV-infected, ART-eligible adults for hepatitis B surface antigen (HBsAg and hepatitis C antibody (HCV Ab at a tertiary hospital in Lusaka, Zambia. We collected basic demographic, medical, and laboratory data to determine predictors for coinfection. Results: Of 323 enrolled patients, 32 (9.9%; 95% CI=6.7-13.2% were HBsAg positive, while 4 (1.2%; 95% CI=0.03-2.4% were HCV Ab positive. Patients with hepatitis B coinfection were more likely to be 200 IU/L was uncommon and did not differ between the two groups (3.4% vs. 2.3%; P=0.5. We were unable to determine predictors of hepatitis C infection due to the low prevalence of disease. Conclusions: HIV and hepatitis B coinfection was common among patients initiating ART at this tertiary care facility. Routine screening for hepatitis B should be considered for HIV-infected persons in southern Africa.
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... Staying Safe Videos for Educators Search English Español Hepatitis KidsHealth / For Parents / Hepatitis Print en español Hepatitis What Is Hepatitis? Hepatitis is an inflammation of the liver. The ...
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International Nuclear Information System (INIS)
Chuangchote, Surawut; Sirivat, Anuvat; Supaphol, Pitt
2007-01-01
The present contribution reports, for the first time, the mechanical and electro-rheological properties of electrospun poly(vinyl alcohol) (PVA) nanofibre mats with or without the incorporation of carbon black (CB) nanoparticles. The effects of sonication and the addition of CB on morphological appearance, average diameter of the as-spun fibre mats, and that of the individual fibres, were thoroughly investigated. Incorporation of CB (1-10% based on the weight of PVA) in 10% w/v PVA solution did not affect the morphology and average diameter of the obtained fibres (∼160 nm), but it affected both the mechanical and the electro-rheological properties of the as-spun PVA/CB fibre mats, in which the mats became more rigid with the addition and increasing amount of CB
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Bulguroglu, I; Guclu-Gunduz, A; Yazici, G; Ozkul, C; Irkec, C; Nazliel, B; Batur-Caglayan, H Z
2017-01-01
Pilates is an exercise method which increases strength and endurance of core muscles and improves flexibility, dynamic postural control and balance. To analyze and compare the effects of Mat and Reformer Pilates methods in Patients with Multiple Sclerosis (MS). Thirty-eight patients with MS were included in the study. Participants were randomly divided into 3 groups as Mat Pilates, Reformer Pilates and control groups. The subjects in the Pilates groups did Mat or Reformer Pilates for 8 weeks, 2 days a week. The control group did breathing and relaxation exercises at home. Balance, functional mobility, core stability, fatigue severity and quality of life were evaluated. Balance, functional mobility, core stability, fatigue severity and quality of life improved after Pilates in Mat and Reformer Pilates groups (p 0.05). When the gain obtained in the Pilates groups is compared, it has been observed that progress has been more in trunk flexor muscle strength in the Reformer Pilates group (p 0.05). As a result, patients with MS have seen similar benefits in Reformer Pilates and Mat Pilates methods.
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DEVELOPMENT OF A MOLECULAR METHOD TO IDENTIFY HEPATITIS E VIRUS IN WATER
Hepatitis E virus (HEV) causes an infectious form of hepatitis associated with contaminated water. By analyzing the sequence of several HEV isolates, a reverse transciption-polymerase chain reaction method was developed and optimized that should be able to identify all of the kn...
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Bagging system, soil stabilization mat, and tent frame for a lunar base
1990-01-01
Georgia Tech's School of Textile and Fiber Engineering and School of Mechanical Engineering participated in four cooperative design efforts this year. Each of two interdisciplinary teams designed a system consisting of a lunar regolith bag and an apparatus for filling this bag. The third group designed a mat for stabilization of lunar soil during takeoff and landing, and a method for packaging and deploying this mat. Finally, the fourth group designed a sunlight diffusing tent to be used as a lunar worksite. Summaries of these projects are given.
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Directory of Open Access Journals (Sweden)
Makbule EREN
2009-11-01
Full Text Available Despite of extensive blood product screening and national immunization programs, chronic hepatitis B and C infections continues to be a global problem with high mortality, morbidity and economic impact. Even though acquisition of these infections mostly occurs in childhood, major problems appear in adulthood. Cirrhosis and HCC are two major expected late events related to chronic hepatitis B and C infections. Rarely, children may also face these complications. To avoid these complications and increase the life expectancy in adults treatment of these two type infections should be started in childhood with appropriate patient selection. In contrast to children, adults are luckier in terms of treatment alternatives. They have the chance to use more potent antivirals with higher genetic barrier and pegylated form of interferons. Recently, the use of pegylated interferon and ribavirin combinations has been approved in children in Chronic HCV infection. However, chronic hepatitis B treatment in children is still dependent on the use of one type antiviral drug and conventional interferon. Treatment in early ages with an antiviral agent that has limited genetic barrier may block the chance of treatment or reduce the response rate in adulthood in chronic hepatitis B infection. This burden indicates the necessity of new therapeutic modalities in children. In this term pegylated interferons may be one of the optiones. In this article we aimed to reviewe the efficacy and safety of conventional and pegylated interferons, for the treatment of Hepatitis C and B infections in children.
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Directory of Open Access Journals (Sweden)
Markus A. Hoffmann
2013-10-01
Full Text Available The use of jute matting in managing the invasive aquatic macrophyte species Elodea nuttallii (Planch. H. St. John and Najas marina ssp. intermedia (Wolfg. ex Gorski Casper (Najas intermedia was studied in laboratory experiments and field trials. Four German lakes with predominant population of Najas intermedia or Elodea nuttalli were chosen for the experiment and areas between 150 and 300 m² were covered with jute textile. The effect of the matting on the growth of invasive and non-invasive macrophytes was determined through comparison with control transects. Biodegradable jute matting successfully suppressed the invasive macrophyte Najas intermedia and significantly reduced the growth of Elodea nuttalli in lakes. The results indicate that the capability of the matting to inhibit the growth of Elodea nuttallii and Najas intermedia depends on the mesh size of the jute weaving and that environmental conditions can affect its efficiency. Various indigenous species like Charales or Potamogeton pusillus L. were able to grow through the jute fabric and populate the treated areas. Until the end of the vegetation period, none of the invasive species were able to penetrate the covering and establish a stable population; in fact, in the subsequent year the jute matting affected only the spread of Najas intermedia. Jute matting proved to be an easy-to-use and cheap method to control the growth of Elodea nuttallii and Najas intermedia.
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Out-of-plane ultimate shear strength of RC mat-slab foundations
International Nuclear Information System (INIS)
Kumagai, Hitoshi; Nukui, Yasushi; Imamura, Akira; Terayama, Takeshi; Hagiwara, Tetsuya; Kojima, Isao
2011-01-01
There have been few studies on the out-of-plane shear in RC mat-slab foundations, and the reasonable method has been demanded to estimate ultimate shear strength of RC mat-slab foundations in the nuclear facilities. In the previous study, the out-of-plane loading tests on the 20 square slab specimens had been performed to collect the fundamental data. In this study, the test results were successfully predicted by 3D non-linear Finite Element Analysis. It has been confirmed that the ultimate shear stress in the slab specimen can be estimated by the Arakawa's formula, which is commonly used to estimate the shear strength of RC beams. (author)
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... Staying Safe Videos for Educators Search English Español Hepatitis B KidsHealth / For Teens / Hepatitis B What's in ... Prevented? Print en español Hepatitis B What Is Hepatitis B? Hepatitis B is an infection of the ...
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Twinrix® (as a combination product containing Hepatitis A Vaccine, Hepatitis B Vaccine) ... Why get vaccinated against hepatitis A?Hepatitis A is a serious liver disease. It is caused by the hepatitis A virus (HAV). HAV is spread from ...
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Clinical evaluation of the Byk LIA-mat CA125 II assay: discussion of a reference value.
Bonfrer, J M; Korse, C M; Verstraeten, R A; van Kamp, G J; Hart, G A; Kenemans, P
1997-03-01
The Byk LIA-mat CA125 II assay was compared with the Centocor IRMA CA125 II. Serum samples studied (n = 1012) were obtained from 652 apparently healthy females, 61 pregnant women, and 299 patients with benign and malignant gynecological tumors. The CA125 II assay value at the 95th percentile of the total healthy group was 29 kU/L for the LIA-mat and 32 kU/L for the Centocor assay. For the LIA-mat assay the 95th percentile was 31 kU/L (Centocor 36 kU/L) for the group 55 years of age. By using ROC curves we found the optimal pretreatment Byk LIA-mat CA125 II value differentiating between benign and malignant ovarian tumors to be 95 kU/L. Pretreatment CA125 values > 1000 kU/L were detected in serum samples of patients with advanced epithelial ovarian cancer.
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Physicochemical characterization of different trademarks of compound Yerba Maté and their herbs
Scipioni,Griselda Patricia; Ferreyra,Darío Jorge; Schmalko,Miguel Eduardo
2007-01-01
The objectives of this study were to evaluate the physicochemical characteristics of the main herbs used in the mixture of yerba maté with other aromatic herbs and the characterization of the trademarks of compound yerba maté. Moisture, water extract, total ash, acid-insoluble ash and caffeine concentration were determined. Results showed higher values of moisture content, total and aci-insoluble ash and lower water extracts in the herbs. Determinations were carried out in nine trademarks of ...
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... Pain: Entire Lesson Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For Veterans and the Public Veterans and the Public Home Hepatitis A Hepatitis B Hepatitis C Hepatitis C Home Getting ...
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Testing the utility of matK and ITS DNA regions for discrimination of Allium species
Molecular phylogenetic analysis of the genus Allium L. has been mainly based on the nucleotide sequences of ITS region. In 2009 matK and rbcL were accepted as a two-locus DNA barcode to classify plant species by the Consortium for the Barcode of Life (CBOL) Plant Working Group. MatK region has been ...
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DEFF Research Database (Denmark)
Amadid, Hanan; Schiødt, Frank Vinholt
2014-01-01
Hypoxic hepatitis (HH), also known as ischaemic hepatitis or shock liver, is an acute liver injury caused by hepatic hypoxia. Cardiac failure, respiratory failure and septic shock are the main underlying conditions. In each of these conditions, several haemodynamic mechanisms lead to hepatic...... hypoxia. A shock state is observed in only 50% of cases. Thus, shock liver and ischaemic hepatitis are misnomers. HH can be a diagnostic pitfall but the diagnosis can be established when three criteria are met. Prognosis is poor and prompt identification and treatment of the underlying conditions...
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International Nuclear Information System (INIS)
Zhou, Rui; Pramoda, Kumari Pallathadka; Liu, Wanshuang; Zhou, Dan; Ding, Guoqiang; He, Chaobin; Leong, Yew Wei; Lu, Xuehong
2014-01-01
Highlights: • The well dispersed POSS-OH promotes the dissociation of both LiClO 4 and BMIM + BF 4 − . • POSS-OH significantly increases the ionic conductivity and lithium transference number. • POSS-OH containing electrolyte improves the optical contrast of electrochromic device. - Abstract: Electrospun polymer nanofibrous mats loaded with ionic liquids (ILs) and lithium salts are promising non-volatile electrolytes owing to their high ionic conductivities. However, the large cations of ILs are difficult to diffuse into solid electrodes, whereas the lithium ions in ILs tend to form anionic complexes with the IL anions, reducing the number of free lithium ions. To address these issues, octa(3-hydroxy-3-methylbutyldimethylsiloxy) polyhedral oligomeric silsesquioxane (POSS-OH), which has large specific surface area and functionality number, is incorporated into electrospun poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-co-HFP) nanofibrous mats, and the mats are used to host LiClO 4 /1-butyl-3-methylimidazolium tetrafluoroborate (BMIM + BF 4 − ). It is found that POSS-OH can significantly increase both ionic conductivity and lithium transference number of the electrolytes owing to the Lewis acid-base interactions of POSS-OH with ClO 4 − and BF 4 − . The electrochromic device using the hybrid mat (with 5 wt% POSS-OH) loaded with LiClO 4 /BMIM + BF 4 − as the electrolyte shows significantly improved transmittance contrast and switching time, as a result of increased number of free lithium ions
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Hepaticocystic duct and a rare extra-hepatic "cruciate" arterial anastomosis: a case report
Directory of Open Access Journals (Sweden)
Abeysuriya Vasitha
2008-02-01
Full Text Available Abstract Introduction The variations in the morphological characteristics of the extra-hepatic biliary system are interesting. Case presentation During the dissection of cadavers to study the morphological characteristics of the extra-hepatic biliary system, a 46-year-old male cadaver was found to have drainage of the common hepatic duct drains directly into the gall bladder neck. The right and left hepatic ducts were not seen extra-hepatically. Further drainage of the bile away from the gallbladder and into the duodenum was provided by the cystic duct. Formation of the common bile duct by the union of the common hepatic duct and cystic duct was absent. Further more the right hepatic artery was found to be communicating with the left hepatic artery by a "bridging artery" after giving rise to the cystic artery. An accessory hepatic artery originated from the "bridging artery" forming a "cruciate" hepatic arterial anastomosis. Conclusion Combination of a Hepaticocystic duct and an aberrant variation in the extra-hepatic arterial system is extremely rare.
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A Matérn model of the spatial covariance structure of point rain rates
Sun, Ying; Bowman, Kenneth P.; Genton, Marc G.; Tokay, Ali
2014-01-01
It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.
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A Matérn model of the spatial covariance structure of point rain rates
Sun, Ying
2014-07-15
It is challenging to model a precipitation field due to its intermittent and highly scale-dependent nature. Many models of point rain rates or areal rainfall observations have been proposed and studied for different time scales. Among them, the spectral model based on a stochastic dynamical equation for the instantaneous point rain rate field is attractive, since it naturally leads to a consistent space–time model. In this paper, we note that the spatial covariance structure of the spectral model is equivalent to the well-known Matérn covariance model. Using high-quality rain gauge data, we estimate the parameters of the Matérn model for different time scales and demonstrate that the Matérn model is superior to an exponential model, particularly at short time scales.
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Evaluating carbon stores at the earth-atmosphere interface: moss and lichen mats of subarctic Alaska
Robert J. Smith; Sarah Jovan; Bruce. McCune
2015-01-01
A fundamental goal of the forest inventory in interior Alaska is to accurately estimate carbon pools in a way that sheds light on the feedbacks between forests and climate. In boreal forests, moss and lichen mats often serve as the interface between soils and the atmosphere, therefore characterizing the biomass and composition of mats is essential for understanding how...
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The Varian MAT-250 mass spectrometer. Steady isotopes laboratory
International Nuclear Information System (INIS)
Hernandez M, V.; Tavera D, M.L.
1997-01-01
This work treats over the performance and applications of the Varian Mat-250 mass spectrometer which is in the environmental isotope laboratory. It can be applied over topics such as: ions formation, acceleration and collimation, ions separation, ions detection, data transformation, sampling, δ notation. (Author)
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Genipin cross-linked electrospun chitosan-based nanofibrous mat as tissue engineering scaffold
Directory of Open Access Journals (Sweden)
Esmaeil Mirzaei
2014-04-01
Full Text Available Objective(s: To improve water stability of electrospun chitosan/ Polyethylene oxide (PEO nanofibers, genipin, a biocompatible and nontoxic agent, was used to crosslink chitosan based nanofibers. Materials and Methods: Different amounts of genipin were added to the chitosan/PEO solutions, chitosan/PEO weight ratio 90/10 in 80 % acetic acid, and the solutions were then electrospun to form nanofibers. The spun nanofibers were exposed to water vapor to complete crosslinking. The nanofibrous membranes were subjected to detailed analysis by scanning electron microscopy (SEM, Fourier transform infrared-attenuated total reflection (FTIR-ATR spectroscopy, swelling test, MTT cytotoxicity, and cell attachment. Results: SEM images of electrospun mats showed that genipin-crosslinked nanofibers retained their fibrous structure after immerging in PBS (pH=7.4 for 24 hours, while the uncrosslinked samples lost their fibrous structure, indicating the water stability of genipin-crosslinked nanofibers. The genipin-crosslinked mats also showed no significant change in swelling ratio in comparison with uncrosslinked ones. FTIR-ATR spectrum of uncrosslinked and genipin-crosslinked chitosan nanofibers revealed the reaction between genipin and amino groups of chitosan. Cytotoxicity of genipin-crosslinked nanofibers was examined by MTT assay on human fibroblast cells in the presence of nanofibers extraction media. The genipin-crosslinked nanofibers did not show any toxic effects on fibroblast cells at the lowest and moderate amount of genipin. The fibroblast cells also showed a good adhesion on genipin-crosslinked nanofibers. Conclusion: This electrospun matrix would be used for biomedical applications such as wound dressing and scaffold for tissue engineering without the concern of toxicity.
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Functional polyaniline nanofibre mats for human adipose-derived stem cell proliferation and adhesion
International Nuclear Information System (INIS)
Abdul Rahman, Norizah; Feisst, Vaughan; Dickinson, Michelle E.; Malmström, Jenny; Dunbar, P. Rod; Travas-Sejdic, Jadranka
2013-01-01
Conductive polymer poly(aniline-co-m-aminobenzoic acid) (P(ANI-co-m-ABA)) and polyaniline (PANI) were blended with a biodegradable, biocompatible polymer, poly(L-lactic acid) and were electrospun into nanofibres to investigate their potential application as a scaffold for human adipose-derived stem cells (hASCs). These polymers, in both conductive and non-conductive form, were electrospun with average fibre diameters of less than 400 nm. Novel nanoindentation results obtained on the individual nanofibres revealed that the elastic moduli of the nanofibres are much higher at the surface (4–10 GPa, h max max >75 nm). The composite nanofibres showed great promise as a scaffold for hASCs as they supported the cell adhesion and proliferation. After 1 week of cell culture hASCs were well spread on the substrates with abundant focal adhesions. The electrospun mats provide the cells with comparably stiff, sub-micron sized fibres as anchoring points on a substrate of high porosity. The conductive nature of these composite nanofibres offers exciting opportunities for electrical stimulation of the cells. - Highlights: ► Polyaniline and its copolymer's nanofibres were prepared by electrospinning. ► The elastic modulus of a single polyaniline composite nanofibres were determined. ► Elastic moduli of the nanofibres are much higher at the surface than the inner core. ► The electrospun mats supported the cell adhesion and proliferation. ► The nanofibres show great promise as a scaffold for adipose derived stem cells
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Taepaiboon, Pattama; Rungsardthong, Uracha; Supaphol, Pitt
2006-05-01
Mats of PVA nanofibres were successfully prepared by the electrospinning process and were developed as carriers of drugs for a transdermal drug delivery system. Four types of non-steroidal anti-inflammatory drug with varying water solubility property, i.e. sodium salicylate (freely soluble in water), diclofenac sodium (sparingly soluble in water), naproxen (NAP), and indomethacin (IND) (both insoluble in water), were selected as model drugs. The morphological appearance of the drug-loaded electrospun PVA mats depended on the nature of the model drugs. The 1H-nuclear magnetic resonance results confirmed that the electrospinning process did not affect the chemical integrity of the drugs. Thermal properties of the drug-loaded electrospun PVA mats were analysed by differential scanning calorimetry and thermogravimetric analysis. The molecular weight of the model drugs played a major role on both the rate and the total amount of drugs released from the as-prepared drug-loaded electrospun PVA mats, with the rate and the total amount of the drugs released decreasing with increasing molecular weight of the drugs. Lastly, the drug-loaded electrospun PVA mats exhibited much better release characteristics of the model drugs than drug-loaded as-cast films.
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Estimation of axial stiffness of plant fibres from compaction of non-woven mats
International Nuclear Information System (INIS)
Gamstedt, E K; Bommier, E; Madsen, B
2014-01-01
Plant fibres are known to show a large variability in stiffness, which makes it time-consuming to experimentally characterize this property by conventional tensile testing. In this work, an alternative method is used, where the average fibre stiffness is back-calculated from compaction tests of in-plane randomly oriented fibre mats. The model by Toll is used to relate the load–displacement curve from the test to the Young modulus of the fibre, taking into account the natural variability in fibre cross section. Several tests have been performed on hemp fibre mats and compared with results from single-fibre tensile testing. The average back-calculated Young's modulus of the fibres was 45 GPa, whereas the average value from tensile testing ranged from 30 to 60 GPa. The straightforward compaction test can be useful in ranking of fibre stiffness, provided that the mat is composed of well-separated fibres and not of twisted yarns. (paper)
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Hepatic encephalopathy associated with hepatic lipidosis in llamas (Lama glama).
Pillitteri, C A; Craig, L E
2013-01-01
Hepatic encephalopathy has been listed as a differential for llamas displaying neurologic signs, but it has not been histopathologically described. This report details the neurologic histopathologic findings associated with 3 cases of hepatic lipidosis with concurrent neurologic signs and compares them to 3 cases of hepatic lipidosis in the absence of neurologic signs and 3 cases without hepatic lipidosis. Brain from all 3 llamas displaying neurologic signs contained Alzheimer type II cells, which were not detected in either subset of llamas without neurologic signs. Astrocytic immunohistochemical staining intensity for glial fibrillary acid protein was decreased in llamas with neurologic signs as compared to 2 of 3 llamas with hepatic lipidosis and without neurologic signs and to 2 of 3 llamas without hepatic lipidosis. Immunohistochemical staining for S100 did not vary between groups. These findings suggest that hepatic encephalopathy may be associated with hepatic lipidosis in llamas.
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International Nuclear Information System (INIS)
Chang, Sam Uel; Choi, Don Gil; Lim, Jae Hoon
2004-01-01
To evaluate the usefulness of screening liver ultrasonography (US) for hepatocellular carcinoma (HCC) detection in patients with chronic hepatitis or hepatic cirrhosis caused by hepatitis B virus (HBV). A retrospective study was performed with 1,189 patients with clinical hepatopathy caused by HBV who underwent screening liver US for HCC detection at least twice. All patients were followed up with liver US examinations (mean, 8.3 times), CT, or MR for at least 3 months (range, 3-102 months; mean, 47 months) for the detection of HCC. The study population was divided into two groups: chronic hepatitis (n=492) and hepatic cirrhosis (n=697), which was further divided into two groups with (n=156) or without (n=541) evident shrinkage. The radiologic examinations that had detected HCC for the first time were analyzed and compared between the groups. Among 20 (4.1%) patients with chronic hepatitis and 132 (18.9%) patients with hepatic cirrhosis diagnosed as HCC, screening US was the modality of detection in 17 (85.0%) of 20 patients with chronic hepatitis and 76 (57.6%) of 132 patients with hepatic cirrhosis (p=0.038, Chi-square test). The detection rate of HCC on screening US between the chronic hepatitis and hepatic cirrhosis with evident shrinkage (51.4%, 19/37) showed a significant difference (p=0.027, Chi-square test). For chronic liver disease caused by HBV, screening US for HCC detection is more useful in patients with chronic hepatitis than with hepatic cirrhosis with evident shrinkage
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Perinatal hepatitis B virus detection by hepatitis B virus-DNA analysis.
De Virgiliis, S; Frau, F; Sanna, G; Turco, M P; Figus, A L; Cornacchia, G; Cao, A
1985-01-01
Maternal transmission of hepatitis B virus infection in relation to the hepatitis B e antigen/antibody system and serum hepatitis B virus-DNA were evaluated. Results indicate that hepatitis B virus-DNA analysis can identify hepatitis B serum antigen positive mothers who may transmit infection to their offspring.
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Effects of filamentous macroalgae mats on growth and survival of eelgrass, Zostera marina, seedlings
DEFF Research Database (Denmark)
Rasmussen, Jonas; Olesen, Birgit; Krause-Jensen, Dorte
2012-01-01
A laboratory experiment was conducted to assess the effect of filamentous algae mats on the performance of seedlings of the eelgrass, Zostera marina. The seedlings were covered by three levels (3, 6 and 9 cm) of natural (Chaetomorpha linum) and imitation algae mats and it was hypothesized that th...
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Directory of Open Access Journals (Sweden)
Cheng-Chang (Sam Pan
2012-02-01
Full Text Available This study is intended to explore a complementary relationship between instructional systems design (ISD and project management in an attempt to build a plausible case for integrating project management as a distinct course in the core of the graduate instructional systems design programs. It is argued that ISD and project management should form a symbiosis from a curriculum perspective, in a hope for the prepared instructional designers to create values for customers. An integrated view of ISD and project management is proposed, using three concepts of project management as a reasonable bridge for the integration. Challenges for the proposed view in this position paper are also stated. Cette étude explore la complémentarité de la conception de matériel pédagogique et de la gestion de projets en vue de justifier l’intégration de la gestion de projets à titre de cours distinct au cœur des programmes des cycles supérieurs en conception de matériel pédagogique. L’étude fait valoir l’intérêt d’une symbiose de la conception de matériel pédagogique et de la gestion de projets du point de vue du programme d’études, afin de préparer les concepteurs pédagogiques formés à créer une plus-value pour les clients. Elle propose une vision intégrée de la conception de matériel pédagogique et de la gestion de projets fondée sur trois concepts de la gestion de projets favorisant une telle intégration. Les défis de la vision proposée dans cet exposé de position sont également énoncés.
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Early serological diagnosis of viral hepatitis A using radiosaturation analysis
Energy Technology Data Exchange (ETDEWEB)
Zichova, M; Vodak, M; Pultar, J; Truksova, B; Stepanek, F
1985-08-21
The possibility was verified of utilizing the determination of specific IgM class antibodies to hepatitis A virus using the method of radiosaturation analysis, for early ethiological diagnosis of hepatitis A. The determination was made using the HAVAB-M kit by Abbott. A high and verifiable presence was found of these antibodies in the first to third weeks of the duration of the disease, positivity was observed up to day 125 from the onset of the diseases. Reliability of the determination of specific IgM antibodies to hepatitis A virus is high. Specific IgM antibodies to hepatitis A, determined using the radiosaturation analysis are a sensitive and specific indicator of the disease. The determination will mainly be used to advantage for identifying patients suffering from the anicteric form of the disease without any clinical manifestations, will substantially improve the ethiological diagnosis of acute hepatitis.
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Early serological diagnosis of viral hepatitis A using radiosaturation analysis
International Nuclear Information System (INIS)
Zichova, M.; Vodak, M.; Pultar, J.; Truksova, B.; Stepanek, F.
1985-01-01
The possibility was verified of utilizing the determination of specific IgM class antibodies to hepatitis A virus using the method of radiosaturation analysis, for early ethiological diagnosis of hepatitis A. The determination was made using the HAVAB-M kit by Abbott. A high and verifiable presence was found of these antibodies in the first to third weeks of the duration of the disease, positivity was observed up to day 125 from the onset of the diseases. Reliability of the determination of specific IgM antibodies to hepatitis A virus is high. Specific IgM antibodies to hepatitis A, determined using the radiosaturation analysis are a sensitive and specific indicator of the disease. The determination will mainly be used to advantage for identifying patients suffering from the anicteric form of the disease without any clinical manifestations, will substantially improve the ethiological diagnosis of acute hepatitis. (author)
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International Nuclear Information System (INIS)
Wang, Jianqiang; Luo, Chao; Qi, Genggeng; Pan, Kai; Cao, Bing
2014-01-01
Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr 2 O 7 2− and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl − and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl − , NO 3 − , and SO 4 2− ) except for PO 4 3− for the pH change
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Noninvasive diagnosis of hepatic fibrosis in chronic hepatitis C
Stauber, Rudolf E; Lackner, Carolin
2007-01-01
Assessment of hepatic fibrosis is important for determining prognosis, guiding management decisions, and monitoring disease. Histological evaluation of liver biopsy specimens is currently considered the reference test for staging hepatic fibrosis. Since liver biopsy carries a small but significant risk, noninvasive tests to assess hepatic fibrosis are desirable. This editorial gives an overview on noninvasive methods currently available to determine hepatic fibrosis and their diagnostic accur...
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The Harris and Beath footprinting mat: diagnostic validity and clinical use.
Silvino, N; Evanski, P M; Waugh, T R
1980-09-01
Pain on the plantar aspect of the forefoot is a common malady whose specific cause is often difficult to diagnose. Using the Berkemann Laboratory version of the original mat of Harris and Beath, and a calibration curve, the patterns on a footprint can be translated into their actual pressure values withhin the range of 0.27 kg/cm2 to 4.80 kg/cm2. Using the procedure presented here, inexperienced subjects were able to estimate the pressure values of random prints of unknown pressure within a standard deviation of 0.28 kg/cm2 from their actual values. The mat is valuable for diagnosis of pressure metatarsalgia and other disorders of the foot. The specificity was 0.77, sensitivity was 0.57, with the sum being equal to 1.34. These results indicate that there is a relatively large population of normal people wit excessive localized pressure under their metatarsal heads who do not complain of pain. The apparently low sensitivty of the mat in this study does not seem to be a limitation, but is an indication of the haziness involved in the differential diagnosis of forefoot pain. Pressure metatarsalgia can be quantitated by analysis of the Harris footprint.
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Zirconium Hydroxide-coated Nanofiber Mats for Nerve Agent Decontamination.
Kim, Sohee; Ying, Wu Bin; Jung, Hyunsook; Ryu, Sam Gon; Lee, Bumjae; Lee, Kyung Jin
2017-03-16
Diverse innovative fabrics with specific functionalities have been developed for requirements such as self-decontamination of chemical/biological pollutants and toxic nerve agents. In this work, Zr(OH) 4 -coated nylon-6,6 nanofiber mats were fabricated for the decontamination of nerve agents. Nylon-6,6 fabric was prepared via the electrospinning process, followed by coating with Zr(OH) 4 , which was obtained by the hydrolysis of Zr(OBu) 4 by a sol-gel reaction on nanofiber surfaces. The reaction conditions were optimized by varying the amounts of Zr(OBu) 4 ,the reaction time, and the temperature of the sol-gel reaction. The composite nanofibers show high decontamination efficiency against diisopropylfluorophosphate, which is a nerve agent analogue, due to its high nucleophilicity that aids in the catalysis of the hydrolysis of the phosphonate ester bonds. Composite nanofiber mats have a large potential and can be applied in specific fields such as military and medical markets. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
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... worldwide 2 Billion People have been infected with Hepatitis B Worldwide The Hepatitis B Foundation is working ... of people living with hepatitis B. Learn About Hepatitis B in 11 Other Languages . Resource Video See ...
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... Navigation Alt+1 Content Alt+2 What is hepatitis? Online Q&A Reviewed July 2016 Q: What ... Question and answer archives Submit a question World Hepatitis Day Posters: Eliminate hepatitis World Hepatitis Day 2017 ...
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Energy Technology Data Exchange (ETDEWEB)
Unalan, Irem [Biomedical Technologies Department, Graduate School of Natural and Applied Sciences, Dokuz Eylul University, Izmir (Turkey); Colpankan, Oylum [Metallurgical and Materials Engineering Department, Faculty of Engineering, Dokuz Eylul University, Izmir (Turkey); Albayrak, Aylin Ziylan, E-mail: aylin.albayrak@deu.edu.tr [Metallurgical and Materials Engineering Department, Faculty of Engineering, Dokuz Eylul University, Izmir (Turkey); Gorgun, Cansu [Biomedical Technologies Department, Graduate School of Natural and Applied Sciences, Ege University, Izmir (Turkey); Urkmez, Aylin Sendemir [Biomedical Technologies Department, Graduate School of Natural and Applied Sciences, Ege University, Izmir (Turkey); Bioengineering Department, Faculty of Engineering, Ege University, Izmir (Turkey)
2016-11-01
The objective of this study was to produce biocompatible plasma-treated and silk-fibroin (SF) modified poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) nanofiber mats. The mats were plasma-treated using O{sub 2} or N{sub 2} gas to increase their hydrophilicity followed by SF immobilization for the improvement of biocompatibility. Contact angle measurements and SEM showed increased hydrophilicity and no disturbed morphology, respectively. Cell proliferation assay revealed that SF modification together with N{sub 2} plasma (PS/N{sub 2}) promoted higher osteoblastic (SaOs-2) cell viability. Although, O{sub 2} plasma triggered more mineral formation on the mats, it showed poor cell viability. Consequently, the PS/N{sub 2} nanofiber mats would be a potential candidate for bone tissue engineering applications. - Highlights: • N{sub 2}-plasma treated and silk fibroin modified mats do not show hydrophobic recovery. • Biomineralization is better on O{sub 2}-plasma treated and silk fibroin modified mats. • SaOS-2 cells like to proliferate on N{sub 2}-plasma treated surfaces.
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Aleksandrovich Yuriev, Denis; Viktorovna Zaitseva, Svetlana; Olegovna Zhdanova, Galina; Yurievich Tolstoy, Mikhail; Dondokovna Barkhutova, Darima; Feodorovna Vyatchina, Olga; Yuryevna Konovalova, Elena; Iosifovich Stom, Devard
2018-02-01
Electrogenic, molecular and some other properties of a microbial mat isolated from the Kuchiger hot spring (Kurumkansky District, Republic of Buryatia) were studied. Molecular analysis showed that representatives of Proteobacteria (85.5 % of the number of classified bacterial sequences) prevailed in the microbial mat of the Kuchiger springs, among which sulfur bacteria of the genus Thiothrix were the most numerous. In the microbial mat there were bacteria from the families Rhodocyclaceae, Comamonadaceae and Flavobacteriaceae. Phylum Bacteroidetes, Cyanobacteria/Chloroplast, Fusobacteria, Fibrobacteres, Acidobacteria, Chlorobi, Spirochaetes, Verrucomicrobia, Firmicutes, Deinococcus-Thermus, Chloroflexi and Actinobacteria are also noted in the composition of the microbial mat. Under the experimental conditions using Kuchiger-mat 16 as bioagents, glucose and peptone as substrates, the power of BFC was 240 and 221 mW / m2, respectively. When replacing the substrate with sodium acetate, the efficiency of the BFC was reduced by a factor of 10 (20 mW / m2). The prospects of using a microbial mat “Kuchiger-16” as an electrogen in BFC when utilizing alkaline waste water components to generate electricity are discussed.
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Engel, Annette Summers; Meisinger, Daniela B; Porter, Megan L; Payn, Robert A; Schmid, Michael; Stern, Libby A; Schleifer, K H; Lee, Natuschka M
2010-01-01
Microbial mats in sulfidic cave streams offer unique opportunities to study redox-based biogeochemical nutrient cycles. Previous work from Lower Kane Cave, Wyoming, USA, focused on the aerobic portion of microbial mats, dominated by putative chemolithoautotrophic, sulfur-oxidizing groups within the Epsilonproteobacteria and Gammaproteobacteria. To evaluate nutrient cycling and turnover within the whole mat system, a multidisciplinary strategy was used to characterize the anaerobic portion of the mats, including application of the full-cycle rRNA approach, the most probable number method, and geochemical and isotopic analyses. Seventeen major taxonomic bacterial groups and one archaeal group were retrieved from the anaerobic portions of the mats, dominated by Deltaproteobacteria and uncultured members of the Chloroflexi phylum. A nutrient spiraling model was applied to evaluate upstream to downstream changes in microbial diversity based on carbon and sulfur nutrient concentrations. Variability in dissolved sulfide concentrations was attributed to changes in the abundance of sulfide-oxidizing microbial groups and shifts in the occurrence and abundance of sulfate-reducing microbes. Gradients in carbon and sulfur isotopic composition indicated that released and recycled byproduct compounds from upstream microbial activities were incorporated by downstream communities. On the basis of the type of available chemical energy, the variability of nutrient species in a spiraling model may explain observed differences in microbial taxonomic affiliations and metabolic functions, thereby spatially linking microbial diversity to nutrient spiraling in the cave stream ecosystem.
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Effect of the flexibility of the base mat on seismic response of a PWR-reactor building
International Nuclear Information System (INIS)
Waas, G.; Riggs, H.R.
1983-01-01
The flexibility of the base mat influences the stiffness and the radiation damping of foundations, In this paper its effect on the seismic response of an axisymmetric PWR-reactor building is investigated. The base mat of the building is stiffened by cylindrical concrete walls and by a rigid block in the center. Soft and stiff soil conditions are considered. The structure and its foundation are modelled by axisymmetric shell and volume elements with Fourier expansions in the circumferential direction. The soil is treated as a horizontally layered viscoelastic medium. Soil and structure are coupled along nodal rings. The stiffness matrix of the soil is computed using an explicit semi-analytic solution for displacements caused by ring loads acting on the surface or within a layered medium. The analysis is performed in the frequency domain, and the response in the time domain is computed by the fast Fourier transformation. The earthquake response is computed with and without including the flexibility of the relatively stiff base mat. The comparison shows that including the flexibility of the mat has hardly any effect on the resonant frequencies and the damping of the fundamental rocking and vertical modes. This is the case for soft and stiff soil conditions. However, the flexibility of the mat strongly affects the first structural deformation mode, in which the external and internal structures deflect in opposite directions. (orig./HP)
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Viral hepatitis as an occupational disease in Poland.
Bilski, Bartosz
2011-07-01
In medical terms, occupational diseases are defined as health disorders specifically associated with the working environment of people and their occupational activity. From the medical and legal perspectives, the vast majority of European countries consider particular diseases to be of occupational origin if they are mentioned in the current list of occupational diseases and caused by exposure to factors in the working environment that are harmful to health. The aim of this study was to analyze the occurrence of cases of viral hepatitis certified as an occupational disease in Poland during 1979-2009. This article presents the medical, economic, and legal aspects of the epidemiology of hepatitis as an occupational disease in Poland. Publically available statistical data on certified occupational diseases in Poland and data contained in individual "occupational disease diagnosis cards" (based on data used in Poland statistical form), regarding certified cases of hepatitis among health care professionals, which were collected by the Department of Occupational Hygiene of the Polish Public Health Service, were analyzed in this study. In Poland, the highest number of cases of hepatitis certified as an occupational disease was observed in 1987. A gradual reduction in the number of cases of hepatitis as an occupational disease has been noted since then. Currently, hepatitis C as an occupational disease is certified more frequently than hepatitis B. In Poland, the number of women with hepatitis certified as an occupational disease is higher than that of men. However, among health care professionals, particularly nurses, this difference is insignificant because women outnumber the men. The existence of such a situation is due to the significant quantitative predominance of women over men among medical personnel, especially among nurses. Immunization of health care professionals against the hepatitis B virus (HBV), introduced in Poland in 1988, was an important factor
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Diagnostic value of liver scintigraphy in fulminant hepatitis and severe acute hepatitis
International Nuclear Information System (INIS)
Shiomi, Susumu; Ikeoka, Naoko; Minowa, Takami; Kuroki, Tetsuo; Harihara, Shigeyoshi; Yamamoto, Sukeo; Ochi, Hironobu; Monna, Takeyuki
1985-01-01
Liver scintigraphy was performed in 12 cases with fulminant hepatitis, in 8 cases with severe acute hepatitis and in 44 cases with acute hepatitis. Scintiphotoes of severe hepatitis showed reduction of liver size, marked visualization of the bone marrow and the spleen, so this pattern was useful to differentiate from acute hepatitis. Relative size of the liver calculated by A.L.I. (anterior liver index) showed significant reduction in severe hepatitis compared with that of acute hepatitis. Three of five patients with died of severe hepatitis showed high uptake in the lung and ribs, but none of fifteen patients with severe hepatitis who recovered showed the abnormal accumulation in the lung and in the ribs. (author)
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... an inflammation of the liver. One type, hepatitis C, is caused by the hepatitis C virus (HCV). It usually spreads through contact with ... childbirth. Most people who are infected with hepatitis C don't have any symptoms for years. If ...
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Serum Hepatitis C virus and hepatitis B surface antigenaemia in ...
African Journals Online (AJOL)
Acute hepatitis is common in Nigeria and hepatitis B virus (HBV) infection has been a major aetiological factor. However, the role of Hepatitis C virus (HCV) infection is yet undetermined. Forty-five consecutive Nigerian patients with acute Icteric hepatitis (AIH) attending the Medical Clinic of the University College Hospital, ...
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Severin, I.; Confurius-Guns, V.; Stal, L.J.
2012-01-01
Microbial mats are often found in intertidal areas experiencing a large range of salinities. This study investigated the effect of changing salinities on nitrogenase activity and on the composition of the active diazotrophic community ( transcript libraries) of three types of microbial mats situated
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[Hepatic alterations in patients with dengue].
Larreal, Yraima; Valero, Nereida; Estévez, Jesús; Reyes, Ivette; Maldonado, Mery; Espina, Luz Marina; Arias, Julia; Meleán, Eddy; Añez, German; Atencio, Ricardo
2005-06-01
Clinical features of Dengue are very variable due to multiple alterations induced by the virus in the organism. Increased levels of transaminases similar to those produced by the Hepatitis virus have been reported in patients with Dengue from hiperendemic zones in Asia. The objectives of this study were to determine alterations in the liver tests in patients with Dengue and to relate them to the disease, clinically and serologically. Clinical history, hemathological tests serum transaminases (ALT y AST) and bilirubin assays were performed in 62 patients with clinical and serological diagnosis of Dengue. According to clinical features 38.7% of the patients with classical (CD) and hemorrhagic (DHF) forms of Dengue reffered abdominal pain and 2 patients with DHF had ictericia and hepatomegaly. Laboratory test findings showed leucopenia in 72.5% in both forms of Dengue and of patients with DHF severe thrombocytopenia (< 50.000 platelets x mm3), long PT and PPT in 70.9%, 23.0% and 42.3%, respectively. Transaminase values five fold higher than the normal values (p < 0.005) were observed in 36.8% and 74.4% of patients with CD and DHF respectively; AST was predominant in both groups. Our results suggest liver damage during the course of Dengue. A differential diagnosis has to be done between the hepatic involvement of Dengue cases and others viral diseases with hepatic disfunctions.
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Thongpin, C.; Srimuk, J.; hipkam, N.; Wachirapong, P.
2015-07-01
In this study, 3 types of natural fibres, i.e. jute, sisal and abaca, were plain weaved to fibre mat. Before weaving, the fibres were treated with 5% NaOH to remove hemi cellulose and lignin. The weaving was performed by hand using square wooden block fit with nails for weaving using one and two types of natural fibres as weft and warp fibre to produce natural fibre mat. The fibre mat was also impregnated in sodium silicate solution extracted from rich husk ash. The pH of the solution was adjusted to pH 7 using H2SO4 before impregnation. After predetermined time, sodium silicate was gelled and deposited on the mat. The fabric mat and sodium silicate coated mat were then impregnated with PLA solution to produce prepreg. Dried pepreg was laminated with PLA sheet using compressing moulding machine to obtain natural fibre mat/PLA composite. The composite containing abaca aligned in longitudinal direction with respect to tension force enhanced Young's modulus more than 300%. Fibre mat composites with abaca aligned in longitudinal direction also showed tensile strength enhancement nearly 400% higher than neat PLA. After coating with sodium silicate, the tensile modulus of the composites was found slightly increased. The silicate coating was disadvantage on tensile strength of the composite due to the effect of sodium hydroxide solution that was used as solvent for silicate extraction from rice husk ash. However, sodium silicate could retard rate of fire propagation about 50%compare to neat PLA and about 10% reduction compared to fibre mat composites without sodium silicate coated fibre mat.
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International Nuclear Information System (INIS)
Thongpin, C; Srimuk, J; Hipkam, N; Wachirapong, P
2015-01-01
In this study, 3 types of natural fibres, i.e. jute, sisal and abaca, were plain weaved to fibre mat. Before weaving, the fibres were treated with 5% NaOH to remove hemi cellulose and lignin. The weaving was performed by hand using square wooden block fit with nails for weaving using one and two types of natural fibres as weft and warp fibre to produce natural fibre mat. The fibre mat was also impregnated in sodium silicate solution extracted from rich husk ash. The pH of the solution was adjusted to pH 7 using H 2 SO 4 before impregnation. After predetermined time, sodium silicate was gelled and deposited on the mat. The fabric mat and sodium silicate coated mat were then impregnated with PLA solution to produce prepreg. Dried pepreg was laminated with PLA sheet using compressing moulding machine to obtain natural fibre mat/PLA composite. The composite containing abaca aligned in longitudinal direction with respect to tension force enhanced Young's modulus more than 300%. Fibre mat composites with abaca aligned in longitudinal direction also showed tensile strength enhancement nearly 400% higher than neat PLA. After coating with sodium silicate, the tensile modulus of the composites was found slightly increased. The silicate coating was disadvantage on tensile strength of the composite due to the effect of sodium hydroxide solution that was used as solvent for silicate extraction from rice husk ash. However, sodium silicate could retard rate of fire propagation about 50%compare to neat PLA and about 10% reduction compared to fibre mat composites without sodium silicate coated fibre mat. (paper)
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... is an inflammation of the liver. One type, hepatitis A, is caused by the hepatitis A virus (HAV). The disease spreads through contact with ... suggest medicines to help relieve your symptoms. The hepatitis A vaccine can prevent HAV. Good hygiene can also ...
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Pierson, B. K.; Parenteau, M. N.; Griffin, B. M.
1999-01-01
At Chocolate Pots Hot Springs in Yellowstone National Park the source waters have a pH near neutral, contain high concentrations of reduced iron, and lack sulfide. An iron formation that is associated with cyanobacterial mats is actively deposited. The uptake of [(14)C]bicarbonate was used to assess the impact of ferrous iron on photosynthesis in this environment. Photoautotrophy in some of the mats was stimulated by ferrous iron (1.0 mM). Microelectrodes were used to determine the impact of photosynthetic activity on the oxygen content and the pH in the mat and sediment microenvironments. Photosynthesis increased the oxygen concentration to 200% of air saturation levels in the top millimeter of the mats. The oxygen concentration decreased with depth and in the dark. Light-dependent increases in pH were observed. The penetration of light in the mats and in the sediments was determined. Visible radiation was rapidly attenuated in the top 2 mm of the iron-rich mats. Near-infrared radiation penetrated deeper. Iron was totally oxidized in the top few millimeters, but reduced iron was detected at greater depths. By increasing the pH and the oxygen concentration in the surface sediments, the cyanobacteria could potentially increase the rate of iron oxidation in situ. This high-iron-content hot spring provides a suitable model for studying the interactions of microbial photosynthesis and iron deposition and the role of photosynthesis in microbial iron cycling. This model may help clarify the potential role of photosynthesis in the deposition of Precambrian banded iron formations.
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The functional hepatic volume assessed by 99mTc-GSA hepatic scintigraphy
International Nuclear Information System (INIS)
Wu, Jin; Ishikawa, Nobuyoshi; Takeda, Tohoru; Pan, Xiao-Qing; Sato, Motohiro; Todoroki, Takeshi; Itai, Yuji; Tanaka, Yumiko; Hatakeyama, Rokurou.
1995-01-01
The accuracy of measurement of the functional hepatic volume by single photon emission computed tomography (SPECT) with 99m Tc-galactosyl serum albumin ( 99m Tc-GSA) was evaluated. 99m Tc-GSA planar scintigraphic images were obtained dynamically and the hepatic SPECT imaging was then performed in 25 patients with hepatobiliary tumors. The patients were divided into 4 groups with normal hepatic function, mild, moderate and severe hepatic dysfunction. The functional hepatic volume determined by SPECT was compared with the morphological hepatic volume determined by computed tomography. The ratio of the hepatic volumes obtained by the two methods was calculated. The mean hepatic volume ratio was 96.6±2.3% in the normal hepatic function group and 95.9±2.2% in the mild dysfunction group (n.s.). In both the moderate and severe hepatic dysfunction groups, the hepatic volume ratio was smaller than that in the normal group (87.9±5.2%, p 15 (r=0.83, p 15 (r=0.74, p 15 (r=0.75, p 99m Tc-GSA faithfully reflects the functioning hepatocyte mass. 99m Tc-GSA scintigraphy and hepatic SPECT therefore provide information regarding global and regional reserve hepatic function. (author)
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Zinnecker, Alicia M.; Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Johathan S.
2014-01-01
The Toolbox for Modeling and Analysis of Thermodynamic Systems (T-MATS) is a tool that has been developed to allow a user to build custom models of systems governed by thermodynamic principles using a template to model each basic process. Validation of this tool in an engine model application was performed through reconstruction of the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) (v2) using the building blocks from the T-MATS (v1) library. In order to match the two engine models, it was necessary to address differences in several assumptions made in the two modeling approaches. After these modifications were made, validation of the engine model continued by integrating both a steady-state and dynamic iterative solver with the engine plant and comparing results from steady-state and transient simulation of the T-MATS and C-MAPSS models. The results show that the T-MATS engine model was accurate within 3 of the C-MAPSS model, with inaccuracy attributed to the increased dimension of the iterative solver solution space required by the engine model constructed using the T-MATS library. This demonstrates that, given an understanding of the modeling assumptions made in T-MATS and a baseline model, the T-MATS tool provides a viable option for constructing a computational model of a twin-spool turbofan engine that may be used in simulation studies.
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Frosi, Giacomo; Biolchi, Alessia; Lo Sapio, Morena; Rigat, Fabio; Gilchrist, Stefanie; Lucidarme, Jay; Findlow, Jamie; Borrow, Ray; Pizza, Mariagrazia; Giuliani, Marzia Monica; Medini, Duccio
2013-10-09
4CMenB (Bexsero), a vaccine developed against invasive meningococcal disease caused by capsular group B strains (MenB), was recently licensed for use by the European Medicines Agency. Assessment of 4CMenB strain coverage in specific epidemiologic settings is of primary importance to predict vaccination impact on the burden of disease. The Meningococcal Antigen Typing System (MATS) was developed to predict 4CMenB strain coverage, using serum bactericidal antibody assay with human complement (hSBA) data from a diverse panel of strains not representative of any specific epidemiology. To experimentally validate the accuracy of MATS-based predictions against strains representative of a specific epidemiologic setting. We used a stratified sampling method to identify a representative sample from all MenB disease isolates collected from England and Wales in 2007-2008, tested the strains in the hSBA assay with pooled sera from infant and adolescent vaccinees, and compared these results with MATS. MATS predictions and hSBA results were significantly associated (P=0.022). MATS predicted coverage of 70% (95% CI, 55-85%) was largely confirmed by 88% killing in the hSBA (95% CI, 72-95%). MATS had 78% accuracy and 96% positive predictive value against hSBA. MATS is a conservative predictor of strain coverage by the 4CMenB vaccine in infants and adolescents. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.
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DEFF Research Database (Denmark)
Klatt, Christian G.; Inskeep, William P.; Herrgard, Markus
2013-01-01
Six phototrophic microbial mat communities from different geothermal springs (YNP) were studied using metagenome sequencing and geochemical analyses. The primary goals of this work were to determine differences in community composition of high-temperature phototrophic mats distributed across...... the Yellowstone geothermal ecosystem, and to identify metabolic attributes of predominant organisms present in these communities that may correlate with environmental attributes important in niche differentiation. Random shotgun metagenome sequences from six phototrophic communities (average 53Mbp/site) were...
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Cost-effectiveness of hepatitis A vaccination for individuals with chronic hepatitis C.
Chapko, Michael K; Yee, Helen S; Monto, Alexander; Dominitz, Jason A
2010-02-17
The incidence of hepatitis A infection in the United States has decreased dramatically in recent years because of childhood immunization programs. A decision analysis of the cost-effectiveness of hepatitis A vaccination for adults with hepatitis C was conducted. No vaccination strategy is cost-effective for adults with hepatitis C using the recent lower anticipated hepatitis A incidence, private sector costs, and a cost-effectiveness criterion of $100,000/QALY. Vaccination is cost-effective only for individuals who have cleared the hepatitis C virus when Department of Veterans Affairs costs are used. The recommendation to vaccinate adults with hepatitis C against hepatitis A should be reconsidered. Published by Elsevier Ltd.
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Directory of Open Access Journals (Sweden)
Guo-Bo Wang
2017-01-01
Full Text Available The foundation might be separated from the supporting soil if the earthquake is big enough, which is known as base mat uplift. This paper proposed a simplified calculation model in which spring element is adopted to simulate the interaction between soil and structure. The load-deformation curve (F-D curve of the spring element can be designated to represent the base mat uplift, in which the pressure can be applied while tensile forces are not allowed. Key factors, such as seismic wave types, seismic wave excitation directions, seismic wave amplitudes, soil shear velocities, structure stiffness, and the ratio of structure height to width (H/B, were considered in the analysis. It is shown that (1 seismic wave type has significant influence on structure response due to different frequency components it contained; (2 the vertical input of seismic wave greatly affected structure response in vertical direction, while it has little impacts in horizontal direction; (3 base mat uplift is easier to take place in soil with higher shear velocity; (4 structure H/B value has complicated influence on base mat uplift. The outcome of this research is assumed to provide some references for the seismic design of the structure due to base mat uplift.
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International Nuclear Information System (INIS)
Pant, Hem Raj; Pandeya, Dipendra Raj; Nam, Ki Taek; Baek, Woo-il; Hong, Seong Tshool; Kim, Hak Yong
2011-01-01
Silver-impregnated TiO 2 /nylon-6 nanocomposite mats exhibit excellent characteristics as a filter media with good photocatalytic and antibacterial properties and durability for repeated use. Silver nanoparticles (NPs) were successfully embedded in electrospun TiO 2 /nylon-6 composite nanofibers through the photocatalytic reduction of silver nitrate solution under UV-light irradiation. TiO 2 NPs present in nylon-6 solution were able to cause the formation of a high aspect ratio spider-wave-like structure during electrospinning and facilitated the UV photoreduction of AgNO 3 to Ag. TEM images, UV-visible and XRD spectra confirmed that monodisperse Ag NPs (approximately 4 nm in size) were deposited selectively upon the TiO 2 NPs of the prepared nanocomposite mat. The antibacterial property of a TiO 2 /nylon-6 composite mat loaded with Ag NPs was tested against Escherichia coli, and the photoactive property was tested against methylene blue. All of the results showed that TiO 2 /nylon-6 nanocomposite mats loaded with Ag NPs are more effective than composite mats without Ag NPs. The prepared material has potential as an economically friendly photocatalyst and water filter media because it allows the NPs to be reused.
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Chemical engineering and thermodynamics using Mat lab
International Nuclear Information System (INIS)
Kim Heon; Kim, Moon Gap; Lee, Hak Yeong; Yeo, Yeong Gu; Ham, Seong Won
2002-02-01
This book consists of twelve chapters and four appendixes about chemical engineering and thermodynamics using Mat lab, which deals with introduction, energy budget, entropy, thermodynamics process, generalization on any fluid, engineering equation of state for PVT properties, deviation of the function, phase equilibrium of pure fluid, basic of multicomponent, phase equilibrium of compound by state equation, activity model and reaction system. The appendixes is about summary of computer program, related mathematical formula and material property of pure component.
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Matted-fiber divertor tagets for sputter resistance
International Nuclear Information System (INIS)
Gierszewski, P.J.; Todreas, N.E.; Mikic, B.; Yang, T.F.
1981-06-01
Reductions in net sputtering yields can be obtained by altering the surface topography to maximize redeposition of sputtered atoms. A simple analysis is used to indicate a potential reduction by a factor of 2 to 5 for matted fiber divertor targets, relatively independent of incident, reflected and sputtered atom distributions. The fiber temperature is also shown to be acceptable, even up to 10 MW/m 2 , for reasonably combinations of materials, fiber diameter and fiber spacing
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Coastal Microbial Mat Diversity along a Natural Salinity Gradient
Bolhuis, H.; Fillinger, L.; Stal, L.J.
2013-01-01
The North Sea coast of the Dutch barrier island of Schiermonnikoog is covered by microbial mats that initiate a succession of plant communities that eventually results in the development of a densely vegetated salt marsh. The North Sea beach has a natural elevation running from the low water mark to
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Flavours – det smakar doft : Upplevelsen av mat och vin i kombination
Hult, Jonas; Lagnetoft, David; Nygren, Nadia
2011-01-01
Inledning: Den vetenskapliga förankringen om mat och vin i kombination är låg. Upplevelsenav en måltid involverar alla de mänskliga sinnena, vilket således har gjort den svår att mäta.Hur stor roll spelar egentligen grundsmakerna och krävs det ytterligare element för att lyfta enkombination av mat och vin till högre höjder?Bakgrund: Förutom smaklökarna på tungan som bildar den grundläggande uppfattningen avdet vi stoppar i munnen, är det främst munkänsla och flavours som bidrar till helheten ...
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Hepatitis E virus and fulminant hepatitis--a virus or host-specific pathology?
Smith, Donald B; Simmonds, Peter
2015-04-01
Fulminant hepatitis is a rare outcome of infection with hepatitis E virus. Several recent reports suggest that virus variation is an important determinant of disease progression. To critically examine the evidence that virus-specific factors underlie the development of fulminant hepatitis following hepatitis E virus infection. Published sequence information of hepatitis E virus isolates from patients with and without fulminant hepatitis was collected and analysed using statistical tests to identify associations between virus polymorphisms and disease outcome. Fulminant hepatitis has been reported following infection with all four hepatitis E virus genotypes that infect humans comprising multiple phylogenetic lineages within genotypes 1, 3 and 4. Analysis of virus sequences from individuals infected by a common source did not detect any common substitutions associated with progression to fulminant hepatitis. Re-analysis of previously reported associations between virus substitutions and fulminant hepatitis suggests that these were probably the result of sampling biases. Host-specific factors rather than virus genotype, variants or specific substitutions appear to be responsible for the development of fulminant hepatitis. © 2014 The Authors. Liver International Published by John Wiley & Sons Ltd.
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Blood lipids analysis in patients with hepatitis and hepatic fibrosis
International Nuclear Information System (INIS)
Si Jianhong
2007-01-01
Objective: To investigate the correlationship between blood hepatic fibrosis markers and blood lipids levels. Methods: Serum hepatic fibrosis markers (HA, PC III, IV-C, LN) levels were determined with RIA and serum lipids (TG, TCh HDL; LDL, apoA1, apoB) were measured with biochemical methods in 98 patients with hepatitis in various stages and 50 controls. Liver biopsy was done in all the hepatitis patients. Results: Hepatic fibrosis was classified into 5 grades (S0-S4) according to the pathology shown in the biopsy specimen. The serum lipid levels decreased along with the increase of severity of fibrosis from S0 to S4. Levels in S4 patients were significantly lower than those in controls (P 0.05). Conclusion: The serum hepatic fibrosis markers levels increased and lipids levels decreased along with the progress of hepatitis from acute to cirrhosis. (authors)
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... Caregiver Support Caregiver Stories Home › What is Hepatic Encephalopathy? Why Your Liver is Important The Connection Between HE and Liver ... Why it’s Important to Treat HE Symptoms of Liver Failure Glossary of terms ... is Hepatic Encephalopathy? Hepatic Encephalopathy, sometimes referred to as portosystemic encephalopathy ...
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Ali, Nidaa; Dashti, Narjes; Salamah, Samar; Sorkhoh, Naser; Al-Awadhi, Husain; Radwan, Samir
2016-03-01
This study describes a bench-scale attempt to bioremediate Kuwaiti, oily water and soil samples through bioaugmentation with coastal microbial mats rich in hydrocarbonoclastic bacterioflora. Seawater and desert soil samples were artificially polluted with 1% weathered oil, and bioaugmented with microbial mat suspensions. Oil removal and microbial community dynamics were monitored. In batch cultures, oil removal was more effective in soil than in seawater. Hydrocarbonoclastic bacteria associated with mat samples colonized soil more readily than seawater. The predominant oil degrading bacterium in seawater batches was the autochthonous seawater species Marinobacter hydrocarbonoclasticus. The main oil degraders in the inoculated soil samples, on the other hand, were a mixture of the autochthonous mat and desert soil bacteria; Xanthobacter tagetidis, Pseudomonas geniculata, Olivibacter ginsengisoli and others. More bacterial diversity prevailed in seawater during continuous than batch bioremediation. Out of seven hydrocarbonoclastic bacterial species isolated from those cultures, only one, Mycobacterium chlorophenolicum, was of mat origin. This result too confirms that most of the autochthonous mat bacteria failed to colonize seawater. Also culture-independent analysis of seawater from continuous cultures revealed high-bacterial diversity. Many of the bacteria belonged to the Alphaproteobacteria, Flavobacteria and Gammaproteobacteria, and were hydrocarbonoclastic. Optimal biostimulation practices for continuous culture bioremediation of seawater via mat bioaugmentation were adding the highest possible oil concentration as one lot in the beginning of bioremediation, addition of vitamins, and slowing down the seawater flow rate. © 2016 The Author. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.
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Hepatitis B immunisation for newborn infants of hepatitis B surface antigen-positive mothers
DEFF Research Database (Denmark)
Lee, C; Gong, Yanzhang; Brok, J
2006-01-01
Hepatitis B vaccine and hepatitis B immunoglobulin are considered for newborn infants of HBsAg-positive mothers to prevent hepatitis B infection.......Hepatitis B vaccine and hepatitis B immunoglobulin are considered for newborn infants of HBsAg-positive mothers to prevent hepatitis B infection....
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Directory of Open Access Journals (Sweden)
Karen G Lloyd
Full Text Available BACKGROUND: Subsurface fluids from deep-sea hydrocarbon seeps undergo methane- and sulfur-cycling microbial transformations near the sediment surface. Hydrocarbon seep habitats are naturally patchy, with a mosaic of active seep sediments and non-seep sediments. Microbial community shifts and changing activity patterns on small spatial scales from seep to non-seep sediment remain to be examined in a comprehensive habitat study. METHODOLOGY/PRINCIPAL FINDINGS: We conducted a transect of biogeochemical measurements and gene expression related to methane- and sulfur-cycling at different sediment depths across a broad Beggiatoa spp. mat at Mississippi Canyon 118 (MC118 in the Gulf of Mexico. High process rates within the mat ( approximately 400 cm and approximately 10 cm from the mat's edge contrasted with sharply diminished activity at approximately 50 cm outside the mat, as shown by sulfate and methane concentration profiles, radiotracer rates of sulfate reduction and methane oxidation, and stable carbon isotopes. Likewise, 16S ribosomal rRNA, dsrAB (dissimilatory sulfite reductase and mcrA (methyl coenzyme M reductase mRNA transcripts of sulfate-reducing bacteria (Desulfobacteraceae and Desulfobulbaceae and methane-cycling archaea (ANME-1 and ANME-2 were prevalent at the sediment surface under the mat and at its edge. Outside the mat at the surface, 16S rRNA sequences indicated mostly aerobes commonly found in seawater. The seep-related communities persisted at 12-20 cm depth inside and outside the mat. 16S rRNA transcripts and V6-tags reveal that bacterial and archaeal diversity underneath the mat are similar to each other, in contrast to oxic or microoxic habitats that have higher bacterial diversity. CONCLUSIONS/SIGNIFICANCE: The visual patchiness of microbial mats reflects sharp discontinuities in microbial community structure and activity over sub-meter spatial scales; these discontinuities have to be taken into account in geochemical and
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How hepatitis D virus can hinder the control of hepatitis B virus.
Directory of Open Access Journals (Sweden)
Maria Xiridou
Full Text Available BACKGROUND: Hepatitis D (or hepatitis delta virus is a defective virus that relies on hepatitis B virus (HBV for transmission; infection with hepatitis D can occur only as coinfection with HBV or superinfection of an existing HBV infection. Because of the bond between the two viruses, control measures for HBV may have also affected the spread of hepatitis D, as evidenced by the decline of hepatitis D in recent years. Since the presence of hepatitis D is associated with suppressed HBV replication and possibly infectivity, it is reasonable to speculate that hepatitis D may facilitate the control of HBV. METHODOLOGY AND PRINCIPAL FINDINGS: We introduced a mathematical model for the transmission of HBV and hepatitis D, where individuals with dual HBV and hepatitis D infection transmit both viruses. We calculated the reproduction numbers of single HBV infections and dual HBV and hepatitis D infections and examined the endemic prevalences of the two viruses. The results show that hepatitis D virus modulates not only the severity of the HBV epidemic, but also the impact of interventions for HBV. Surprisingly we find that the presence of hepatitis D virus may hamper the eradication of HBV. Interventions that aim to reduce the basic reproduction number of HBV below one may not be sufficient to eradicate the virus, as control of HBV depends also on the reproduction numbers of dual infections. CONCLUSIONS AND SIGNIFICANCE: For populations where hepatitis D is endemic, plans for control programs ignoring the presence of hepatitis D may underestimate the HBV epidemic and produce overoptimistic results. The current HBV surveillance should be augmented with monitoring of hepatitis D, in order to improve accuracy of the monitoring and the efficacy of control measures.
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Kim, Young Won; Lee, Han Bit; Yeon, Si Mo; Park, Jeanho; Lee, Hye Jin; Yoon, Jonghun; Park, Suk Hee
2018-02-14
Here, we present a simple yet highly efficient method to enhance the output performance of a piezoelectric device containing electrospun nanofiber mats. Multiple nanofiber mats were assembled together to harness larger piezoelectric sources in the as-spun fibers, thereby providing enhanced voltage and current outputs compared to those of a single-mat device. In addition to the multilayer assembly, microbead-based electrodes were integrated with the nanofiber mats to deliver a complexed compression and tension force excitation to the piezoelectric layers. A vacuum-packing process was performed to attain a tight and well-organized assembly of the device components even though the total thickness was several millimeters. The integrated piezoelectric device exhibited a maximum voltage and current of 10.4 V and 2.3 μA, respectively. Furthermore, the robust integrity of the device components could provide high-precision sensitivity to perceive small pressures down to approximately 100 Pa while retaining a linear input-output relationship.
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Energy Technology Data Exchange (ETDEWEB)
Wang, Jianqiang; Luo, Chao [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Qi, Genggeng [Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Pan, Kai, E-mail: pankai@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China); Department of Materials Science and Engineering, Cornell University, Ithaca, NY (United States); Cao, Bing, E-mail: bcao@mail.buct.edu.cn [Key Laboratory of Carbon Fiber and Functional Polymers, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029 (China)
2014-10-15
Graphical abstract: - Highlights: • PAN/PPy core/shell nanofiber used for Cr(VI) removal. • Adsorption mechanisms were investigated. • Selective adsorption performances were investigated. - Abstract: Polyacrylonitrile/polypyrrole (PAN/PPy) core/shell nanofiber mat was prepared through electrospinning followed by a simple chemical oxidation method. The polypyrrole-functionalized nanofiber mats showed selective adsorption performance for anions. The interaction between heavy metal anions and polypyrrole (especially the interaction between Cr{sub 2}O{sub 7}{sup 2−} and polypyrrole) during the adsorption process was studied. The results showed that the adsorption process included two steps: one was the anion exchange process between the Cl{sup −} and Cr(VI), and the other was the redox process for the Cr(VI) ions. The adsorption amount was related to the protonation time of the PAN/PPy nanofiber mat and increased as protonation time increased. Meanwhile, the Cr(VI) ions were reduced to Cr(III) through the reaction with amino groups of polypyrrole (from secondary amines to tertiary amines). PAN/PPy nanofiber mat showed high selectivity for Cr(VI), and the adsorption performance was nearly unaffected by other co-existing anions (Cl{sup −}, NO{sub 3}{sup −}, and SO{sub 4}{sup 2−}) except for PO{sub 4}{sup 3−} for the pH change.
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Travelers' Health: Hepatitis C
... Chapter 3 - Hepatitis B Chapter 3 - Hepatitis E Hepatitis C Deborah Holtzman INFECTIOUS AGENT Hepatitis C virus ( ... mother to child. Map 3-05. Prevalence of hepatitis C virus infection 1 PDF Version (printable) 1 ...
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Travelers' Health: Hepatitis A
... 3 - Helminths, Soil-Transmitted Chapter 3 - Hepatitis B Hepatitis A Noele P. Nelson INFECTIOUS AGENT Hepatitis A ... hepatitis/HAV Table 3-02. Vaccines to prevent hepatitis A VACCINE TRADE NAME (MANUFACTURER) AGE (Y) DOSE ...
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Travelers' Health: Hepatitis B
... Chapter 3 - Hepatitis A Chapter 3 - Hepatitis C Hepatitis B Francisco Averhoff INFECTIOUS AGENT Hepatitis B virus ( ... progression of disease. Map 3-04. Prevalence of hepatitis B virus infection 1 PDF Version (printable) 1 ...
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International Nuclear Information System (INIS)
Rath, Goutam; Hussain, Taqadus; Chauhan, Gaurav; Garg, Tarun; Goyal, Amit Kumar
2016-01-01
Systemic antibiotic therapy in post-operative wound care remain controversial leading to escalation in levels of multi-resistant bacteria with unwanted morbidity and mortality. Recently zinc (Zn) because of multiple biophysiological functions, gain considerable interest for wound care. Based on our current understanding, the present study was designed with an intent to produce improve therapeutic approaches for post-operative wound management using composite multi-functional antibiotic carrier. The study involved the fabrication, characterization and pre-clinical evaluation of cefazolin nanofiber mats loaded with zinc oxide (ZnO) and comparing co-formulated mats with individual component, enable a side by side comparison of the benefits of our intervention. Minimum inhibitory concentration (MIC) of the drug, ZnO nanoparticles (ZnONPs) and drug-ZnONP mixture against Staphylococcus aureus was determined using micro dilution assay. The fabricated nanofibers were then evaluated for in-vitro antimicrobial activity and the mechanism of inhibition was predicted by scanning electron microscopy (SEM). Further these nanofiber mats were evaluated in-vivo for wound healing efficacy in Wistar rats. Study revealed that the average diameter of the nanofibers is around 200–900 nm with high entrapment efficiency and display sustained drug release behavior. The combination of ZnO and cefazolin in 1:1 weight ratio showed higher anti-bacterial activity of 1.9 ± 0.2 μg/ml. Transmission electron microscopy of bacterial cells taken from the zone of inhibition revealed the phenomenon of cell lysis in tested combination related to cell wall disruption. Further composite medicated nanofiber mats showed an accelerated wound healing as compared to plain cefazolin and ZnONP loaded mats. Macroscopical and histological evaluations demonstrated that ZnONP hybrid cefazolin nanofiber showed enhanced cell adhesion, epithelial migration, leading to faster and more efficient collagen synthesis
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Changing Epidemiology of Hepatitis A and Hepatitis E Viruses in China, 1990-2014.
Ren, Xiang; Wu, Peng; Wang, Liping; Geng, Mengjie; Zeng, Lingjia; Zhang, Jun; Xia, Ningshao; Lai, Shengjie; Dalton, Harry R; Cowling, Benjamin J; Yu, Hongjie
2017-02-01
We compared the epidemiology of hepatitis A and hepatitis E cases in China from 1990-2014 to better inform policy and prevention efforts. The incidence of hepatitis A cases declined dramatically, while hepatitis E incidence increased. During 2004-2014, hepatitis E mortality rates surpassed those of hepatitis A.
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... and Public Home » Hepatitis C » Treatment Decisions Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For ... can I find out about participating in a hepatitis C clinical trial? Many trials are being conducted ...
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... the Public Home Hepatitis A Hepatitis B Hepatitis C Hepatitis C Home Getting Tested Just Diagnosed Treatment Choice Program ... Pain Mental Health Sex and Sexuality (for Hepatitis C) Success Stories FAQs For Health Care Providers Provider ...
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Full Text Available ... Caregiver Support Caregiver Stories Home › What is Hepatic Encephalopathy? Why Your Liver is Important The Connection Between HE and Liver ... Why it’s Important to Treat HE Symptoms of Liver Failure Glossary of terms ... is Hepatic Encephalopathy? Hepatic Encephalopathy, sometimes referred to as portosystemic encephalopathy ...
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[Immunological status of patients with amebic hepatic abscess].
Canto Solís, A; Miranda Feria, A J; Medina Martinez, J; Teran Ortíz, L A; Suárez Sánchez, F
1975-01-01
The authors studied 10 cases of amoebic hepatic abscess documented by clinical evidence and confirmed by laboratory tests, liver scan and a good response to treatment. The immunological state of the patients was determined by protein electrophoresis, immunoelectrophoresis, counter-immunoelectrophoresis, radial immunodiffusion and roset formation for T and B lymphocytes. It is concluded that the alterations of cellular and humoral immunity is evident in cases of amoebic hepatic abscess; this alterations are more clear in the acute form of the illness and the immunological deficiency is more significant in the celular immunity.
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Directory of Open Access Journals (Sweden)
Susanna A. Wood
2017-10-01
Full Text Available The prevalence of benthic proliferations of the anatoxin-producing cyanobacterium Phormidium are increasing in cobble-bed rivers worldwide. Studies to date have shown high spatial and temporal variability in anatoxin concentrations among mats. In this study we determined anatoxin quotas (toxins per cell in field samples and compared these results to the conventionally-used concentrations (assessed per dry weight of mat. Three mats were selected at sites in two rivers and were sampled every 2–3 h for 24–26 h. The samples were lyophilized and ground to a fine homogenous powder. Two aliquots of known weights were analyzed for anatoxin congeners using liquid chromatography-mass spectrometry, or digital droplet PCR with Phormidium-specific anaC primers to measure absolute quantities of gene copies. Anatoxin concentrations in the mats varied 59- and 303-fold in the two rivers over the study periods. A similar pattern was observed among gene copies (53- and 2828-fold. When converted to anatoxin quotas there was markedly less variability (42- and 16-fold, but significantly higher anatoxin quotas were observed in mats from the second river (p < 0.001, Student’s t-test. There were no obvious temporal patterns with high and low anatoxin concentrations or quotas measured at each sampling time and across the study period. These results demonstrate that variability in anatoxin concentrations among mats is primarily due to the abundance of toxic genotypes. No consistent modulation in anatoxin production was observed during the study, although significant differences in anatoxin quotas among rivers suggest that site-specific physiochemical or biological factors may influence anatoxin production.
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Effect of salinity on carbon and sulfur cycles in Umm Alhool sabkha microbial mat ecosystem in Qatar
Alnajjar, Mohammad Ahmad
2012-10-19
Microbial mats are only present under extreme conditions, where grazing by higher organisms is limited. Therefore, microbial mats may provide insight into extraterrestrial life, due to their adaptations to extreme temperatures, desiccation or salinity. They are faced with a diurnal cycle with variable length based on their location, which exposes them to extreme salinity conditions (i.e., water withdrawal and high evaporation). Cyanobacteria in the photic zone of a mat ecosystem supply the other microorganism with the required organic material to produce energy and grow. Subsequently, this will reproduce the nutrients needed by the phototrophs through elemental re-mineralization. In this work, we investigated the effect of water salinity that covers the microbial mat ecosystem of Umm Alhool sabkha, Qatar, regarding the most important processes within microbial mats: photosynthesis and sulfate reduction (SR). Our results showed that both photosynthetic and sulfate reduction rates decreased with increasing the salinity. The microbial community structure, assessed by 454 pyro-sequencing, revealed that the cyanobacterial community structure changed in response to the change in salinity. This was not the case for the sulfate reducer community structure, which stayed as it is in the mats incubated at different salinities. Therefore, we speculate that salinity affects the photosynthetic community structure, and consequently affects the photosynthetic activity of the whole ecosystem. However, sulfate reduction rates decreased due to less organic material supply from the upper layers and not due to change in microbial community structure of SR. Other factors such as the activity of the enzymes could also have an effect on SRR, but it was not investigated in this study.
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VocMat projekt - uudsed e-õppe võimalused turismiasjalistele / Heli Tooman
Tooman, Heli, 1949-
2008-01-01
Turismivaldkonna spetsialistidele mõeldud koolitusprojektist VocMat (Vocational Management Training for the Tourism Industry). Projekti partneriteks Eestis on Ettevõtluse Arendamise Sihtasutuse Turismiarenduskeskus ja Tartu Ülikooli Pärnu kolledzh. Lisa: Kokkuvõte
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Fulminant Hepatic Failure Secondary to Primary Hepatic Angiosarcoma
Directory of Open Access Journals (Sweden)
Ayokunle T. Abegunde
2015-01-01
Full Text Available Background. Hepatic angiosarcoma is a rare and aggressive tumor that often presents at an advanced stage with nonspecific symptoms. Objective. To report a case of primary hepatic angiosarcoma in an otherwise healthy man with normal liver function tests two months prior to presenting with a short period of jaundice that progressed to fulminant hepatic failure. Methods. Case report and review of literature. Conclusion. This case illustrates the rapidity of progression to death after the onset of symptoms in a patient with hepatic angiosarcoma. Research on early diagnostic strategies and newer therapies are needed to improve prognosis in this rare and poorly understood malignancy with limited treatment options.
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Functional polyaniline nanofibre mats for human adipose-derived stem cell proliferation and adhesion
Energy Technology Data Exchange (ETDEWEB)
Abdul Rahman, Norizah, E-mail: norizah@science.putra.edu.my [Polymer Electronics Research Centre, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland (New Zealand); Department of Chemistry, University of Putra Malaysia, 43400 UPM Serdang, Selangor Darul Ehsan (Malaysia); Feisst, Vaughan [School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland (New Zealand); Dickinson, Michelle E. [Department of Chemical and Materials Engineering, The University of Auckland, Private Bag 92019, Auckland (New Zealand); Malmström, Jenny [Polymer Electronics Research Centre, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland (New Zealand); Dunbar, P. Rod [School of Biological Sciences, The University of Auckland, Private Bag 92019, Auckland (New Zealand); Maurice Wilkins Centre, Private Bag 92019, Auckland (New Zealand); Travas-Sejdic, Jadranka, E-mail: j.travas-sejdic@auckland.ac.nz [Polymer Electronics Research Centre, School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland (New Zealand); MacDiarmid Institute for Advanced Materials and Nanotechnology, P.O. Box 600, Wellington 6140 (New Zealand)
2013-02-15
Conductive polymer poly(aniline-co-m-aminobenzoic acid) (P(ANI-co-m-ABA)) and polyaniline (PANI) were blended with a biodegradable, biocompatible polymer, poly(L-lactic acid) and were electrospun into nanofibres to investigate their potential application as a scaffold for human adipose-derived stem cells (hASCs). These polymers, in both conductive and non-conductive form, were electrospun with average fibre diameters of less than 400 nm. Novel nanoindentation results obtained on the individual nanofibres revealed that the elastic moduli of the nanofibres are much higher at the surface (4–10 GPa, h{sub max} <75 nm) than in the inner fibre core (2–4 GPa, h{sub max} >75 nm). The composite nanofibres showed great promise as a scaffold for hASCs as they supported the cell adhesion and proliferation. After 1 week of cell culture hASCs were well spread on the substrates with abundant focal adhesions. The electrospun mats provide the cells with comparably stiff, sub-micron sized fibres as anchoring points on a substrate of high porosity. The conductive nature of these composite nanofibres offers exciting opportunities for electrical stimulation of the cells. - Highlights: ► Polyaniline and its copolymer's nanofibres were prepared by electrospinning. ► The elastic modulus of a single polyaniline composite nanofibres were determined. ► Elastic moduli of the nanofibres are much higher at the surface than the inner core. ► The electrospun mats supported the cell adhesion and proliferation. ► The nanofibres show great promise as a scaffold for adipose derived stem cells.
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Transfusion-associated hepatitis before the screening of blood for hepatitis risk factors
DEFF Research Database (Denmark)
Engle, Ronald E; Bukh, Jens; Alter, Harvey J
2014-01-01
%) with HBV alone, and one (3%) with both viruses. Overall, 100% of patients with hepatitis and 39% of those without hepatitis were infected with HBV and/or HCV; one patient was also infected with hepatitis E virus. The donor carrier rate for HBV and/or HCV was estimated to be more than 6%; contemporaneously......%) developed biochemical evidence of hepatitis; of these, 20 (67%) were infected with hepatitis C virus (HCV) alone, four (13%) with hepatitis B virus (HBV) alone, and six (20%) with both viruses. Among the 36 patients who did not develop hepatitis, four (11%) were newly infected with HCV alone, nine (25...... prepared pooled normal human plasma was also contaminated with multiple hepatitis viruses. CONCLUSION: TAH virus infections were a larger problem than perceived 50 years ago and HCV was the predominant agent transmitted. All hepatitis cases could be attributed to HCV and/or HBV and hence...
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Schiffman, Jessica D.
2011-11-01
The incorporation of silver nanoparticles (AgNPs) into polymeric nanofibers has attracted a great deal of attention due to the strong antimicrobial activity that the resulting fibers exhibit. However, bactericidal efficacy of AgNP-coated electrospun fibrous mats has not yet been demonstrated. In this study, polysulfone (PSf) fibers were electrospun and surface-modified using an oxygen plasma treatment, which allowed for facile irreversible deposition of cationically charged polyethyleneimine (PEI)-AgNPs via electrostatic interactions. The PSf-AgNP mats were characterized for relative silver concentration as a function of plasma treatment time using ICP-MS and changes in contact angle. Plasma treatment of 60 s was the shortest time required for maximum loss of bacteria (Escherichia coli) viability. Time-dependent bacterial cytotoxicity studies indicate that the optimized PSf-AgNP mats exhibit a high level of inactivation against both Gram negative bacteria, Escherichia coli, and Gram positive bacteria, Bacillus anthracis and Staphylococcus aureus. © 2011 American Chemical Society.
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[Viral hepatitis in travellers].
Abreu, Cândida
2007-01-01
Considering the geographical asymmetric distribution of viral hepatitis A, B and E, having a much higher prevalence in the less developed world, travellers from developed countries are exposed to a considerable and often underestimated risk of hepatitis infection. In fact a significant percentage of viral hepatitis occurring in developed countries is travel related. This results from globalization and increased mobility from tourism, international work, humanitarian and religious missions or other travel related activities. Several studies published in Europe and North America shown that more than 50% of reported cases of hepatitis A are travel related. On the other hand frequent outbreaks of hepatitis A and E in specific geographic areas raise the risk of infection in these restricted zones and that should be clearly identified. Selected aspects related with the distribution of hepatitis A, B and E are reviewed, particularly the situation in Portugal according to the published studies, as well as relevant clinical manifestations and differential diagnosis of viral hepatitis. Basic prevention rules considering enteric transmitted hepatitis (hepatitis A and hepatitis E) and parenteral transmitted (hepatitis B) are reviewed as well as hepatitis A and B immunoprophylaxis. Common clinical situations and daily practice "pre travel" advice issues are discussed according to WHO/CDC recommendations and the Portuguese National Vaccination Program. Implications from near future availability of a hepatitis E vaccine, a currently in phase 2 trial, are highlighted. Potential indications for travellers to endemic countries like India, Nepal and some regions of China, where up to 30% of sporadic cases of acute viral hepatitis are caused by hepatitis E virus, are considered. Continued epidemiological surveillance for viral hepatitis is essential to recognize and control possible outbreaks, but also to identify new viral hepatitis agents that may emerge as important global health
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Electrospun silk-elastin-like fibre mats for tissue engineering applications
International Nuclear Information System (INIS)
Machado, Raul; Da Costa, André; Padrão, Jorge; Gomes, Andreia; Casal, Margarida; Sencadas, Vitor; Costa, Carlos M; Lanceros-Méndez, Senentxu; Garcia-Arévalo, Carmen; Rodríguez-Cabello, José Carlos
2013-01-01
Protein-based polymers are present in a wide variety of organisms fulfilling structural and mechanical roles. Advances in protein engineering and recombinant DNA technology allow the design and production of recombinant protein-based polymers (rPBPs) with an absolute control of its composition. Although the application of recombinant proteins as biomaterials is still an emerging technology, the possibilities are limitless and far superior to natural or synthetic materials, as the complexity of the structural design can be fully customized. In this work, we report the electrospinning of two new genetically engineered silk-elastin-like proteins (SELPs) consisting of alternate silk- and elastin-like blocks. Electrospinning was performed with formic acid and aqueous solutions at different concentrations without addition of further agents. The size and morphology of the electrospun structures was characterized by scanning electron microscopy showing its dependence on the concentration and solvent used. Treatment with methanol-saturated air was employed to stabilize the structure and promote water insolubility through a time-dependent conversion of random coils into β-sheets (FTIR). The resultant methanol-treated electrospun mats were characterized for swelling degree (570–720%), water vapour transmission rate (1083 g/m 2 /day) and mechanical properties (modulus of elasticity ∼126 MPa). Furthermore, the methanol-treated SELP fibre mats showed no cytotoxicity and were able to support adhesion and proliferation of normal human skin fibroblasts. Adhesion was characterized by a filopodia-mediated mechanism. These results demonstrate that SELP fibre mats can provide promising solutions for the development of novel biomaterials suitable for tissue engineering applications. (paper)
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Response of cyanobacterial mats to nutrient and salinity changes
Czech Academy of Sciences Publication Activity Database
Rejmánková, E.; Komárková, Jaroslava
2005-01-01
Roč. 83, č. 2 (2005), s. 87-107 ISSN 0304-3770. [INTECOL International Wetlands Conference /7./. Utrecht, 25.07.2004-30.7.2004] Grant - others:NSF(US) 0089211 Institutional research plan: CEZ:AV0Z60170517 Keywords : cyanobacterial mats * Belize * P-N impact Subject RIV: EH - Ecology, Behaviour Impact factor: 1.344, year: 2005
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Evaluation of the WavTrac Expeditionary Mobility Matting System
2017-04-01
Dr. Timothy W. Rushing was Chief, APB; Dr. Gordon W. McMahon was Chief, ESMD; and Nicholas Boone was the Technical Director for Force Projection...were tan in color and had a nonskid material applied to the wearing surface. Typical mat dimensions were 12 ft, 2 in. wide by 48 ft, 6 in. long
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Advanced HVAC modeling with FemLab/Simulink/MatLab
Schijndel, van A.W.M.
2003-01-01
The combined MatLab toolboxes FemLab and Simulink are evaluated as solvers for HVAC problems based on partial differential equations (PDEs). The FemLab software is designed to simulate systems of coupled PDEs, 1-D, 2-D or 3-D, nonlinear and time dependent. In order to show how the program works, a
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Attitudes and Awareness Regarding Hepatitis B and Hepatitis C ...
African Journals Online (AJOL)
in many cases hepatitis B and C can lead to permanent liver ... Department of Public Health Dentistry, Gian Sagar Dental College and Hospital, 1Department of Oral Surgery, Gian ... training among HCWs to prevent the spread of hepatitis B virus and hepatitis C virus. ..... primary care physicians following the Department of.
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[Comparison of clinical and laboratory characteristics of viral hepatitis A and E in Montenegro].
Terzić, Dragica; Mijović, Gordana; Dupanović, Brankica; Drasković, Nenad; Svirtlih, Neda
2010-01-01
Hepatitis E has many similarities in with hepatitis A concerning clinical picture, route of transmission and nonexistence of chronicity. Comparison of clinical and laboratory parameters of patients with hepatitis A and E to estimate characteristics of these diseases. Total of 54 patients divided into two groups was investigated: 27 had hepatitis A, others had hepatitis E. Detailed history past, clinical examination, liver function tests and ultrasonography of the upper abdomen, were done in all patients. Aetiology of viral hepatitis was investigated serologically by enzyme immunoassay (ELISA) using commercial kits for following viruses: Hepatitis A-E viruses, cytomegalovirus, and Epstein-Barr virus. Asymptomatic infections (29.6%) and clinical forms without jaundice (59.3%) were more frequent in patients with hepatitis E. Splenomegaly was found more frequent in patients with hepatitis A than in hepatitis E (66.7% vs. 33.3%). Patients with hepatitis E had significantly lower activity of aminotransferases than patients with hepatitis A. A significant increase of gamma-glutamyltranspeptidase was found in patients with hepatitis E (mean value: 120 IU/L). Our results are in concordance with other reports that hepatitis E virus infection is more common asymptomatic disease than hepatitis A. In addition, hepatocyte necrosis in hepatitis E is less extensive than in hepatitis A measured by the activity of aminotransferases. Contrary to that the value of gamma-glutamyltranspeptidase is more increased in hepatitis E than in hepatitis A without exact explanation so far: Viral hepatitis E and A have differences in some clinical features and laboratory parameters although both diseases principally have resolved without consequences after 6-8 weeks.
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International Nuclear Information System (INIS)
Taepaiboon, Pattama; Rungsardthong, Uracha; Supaphol, Pitt
2007-01-01
Cross-linking of electrospun (e-spun) fibre mats (beaded fibre morphology with the average diameter of the fibre segments between beads being ∼108 nm) of poly(vinyl alcohol) (PVA) containing sodium salicylate (SS), used as the model drug, was achieved by exposing the fibre mats to the vapour from 5.6 M aqueous solution of either glutaraldehyde or glyoxal for various exposure time intervals, followed by a heat treatment in a vacuum oven. With increasing the exposure time in the cross-linking chamber, the morphology of the e-spun fibre mats gradually changed from a porous to dense structure. Both the degree of swelling and the percentage of weight loss of the cross-linked fibre mats (i.e. ∼200-530% and ∼15-57%, respectively) were lower than those of the untreated ones (i.e. ∼610% and ∼67%, respectively). Cross-linking was also responsible for the monotonic increase in the storage moduli of the cross-linked SS-loaded e-spun PVA fibre mats with increasing exposure time in the cross-linking chamber. The release characteristic of the model drug from the SS-loaded e-spun PVA fibre mats both before and after cross-linking was assessed by the transdermal diffusion through a pig skin method. The cumulative release of the drug from these matrices could be divided into two stages: 0-4 and 4-72 h, in which the amount of SS released in the first stage increased very rapidly, while it was much slower in the second stage. Cross-linking slowed down the release of SS from the drug-loaded fibre mats appreciably and both the rate of release and the total amount of the drug released were decreasing functions of the exposure time interval in the cross-linking chamber. Lastly, the cross-linked SS-loaded e-spun PVA fibre mats were non-toxic to normal human dermal fibroblasts
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Application of Serum Hepatic Fibrosis Indices in the Diagnosis of Hepatic Disease
International Nuclear Information System (INIS)
Lu Yanting; Wang Taisong; Gu Xin
2010-01-01
To investigate the significance of combined detection of laminin (LN), collagen type IV (CIV), hyaluronic acid (HA) and precollagen type III (PCIII) in the diagnosis of hepatic fibrosis. The serum levels of LN, CIV, HA and PCIII in 143 patients with hepatic disease and 41 healthy controls were measured by radioimmunoassay (RIA). The results showed that the serum levels of LN, CIV, HA and PCIII in patients with hepatic disease were significantly higher than those of the control group (P<0.01), and the serum levels of those markers were related to the severity of the chronic hepatic disease. The highest serum levels were found in serious chronic hepatitis group and hepatic fibrosis group,and the increase of serum HA and PCIII was most remarkable. Combined detection of LN, CIV, HA and PCIII is a sensitive and reliable method in the diagnosis of hepatic fibrosis, but the four serum indices can not be used in differentiating serious chronic hepatitis and hepatic fibrosis. (authors)
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Zinnecker, Alicia M.; Chapman, Jeffryes W.; Lavelle, Thomas M.; Litt, Jonathan S.
2014-01-01
The Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS) is a tool that has been developed to allow a user to build custom models of systems governed by thermodynamic principles using a template to model each basic process. Validation of this tool in an engine model application was performed through reconstruction of the Commercial Modular Aero-Propulsion System Simulation (C-MAPSS) (v2) using the building blocks from the T-MATS (v1) library. In order to match the two engine models, it was necessary to address differences in several assumptions made in the two modeling approaches. After these modifications were made, validation of the engine model continued by integrating both a steady-state and dynamic iterative solver with the engine plant and comparing results from steady-state and transient simulation of the T-MATS and C-MAPSS models. The results show that the T-MATS engine model was accurate within 3% of the C-MAPSS model, with inaccuracy attributed to the increased dimension of the iterative solver solution space required by the engine model constructed using the T-MATS library. This demonstrates that, given an understanding of the modeling assumptions made in T-MATS and a baseline model, the T-MATS tool provides a viable option for constructing a computational model of a twin-spool turbofan engine that may be used in simulation studies.
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2010-10-01
... load restraining value of a friction mat, determined? 393.108 Section 393.108 Transportation Other... load restraining value of a friction mat, determined? (a) The working load limit (WLL) of a tiedown... load limits. (g) Friction mats which are not marked or rated by the manufacturer shall be considered to...
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Cisneros, Lígia de Loiola; Fonseca, Tiago H S; Abreu, Vivianni C
2010-01-01
High plantar pressure is a proven risk factor for ulceration among individuals with diabetes mellitus. The Harris and Beath footprinting mat is one of the tools used in screening for foot ulceration risk among these subjects. There are no reports in the literature on the reliability of footprint analysis using print pattern criteria. The aim of this study was to evaluate the inter- and intra-examiner reliability of the analysis of footprint patterns obtained using the Harris and Beath footprinting mat. Footprints were taken from 41 subjects using the footprinting mat. The images were subjected to analysis by three independent examiners. To investigate the intra-examiner reliability, the analysis was repeated by one of the examiners one week later. The weighted kappa coefficient was excellent (K(w) > 0.80) for the inter- and intra-examiner analyses for most of the points studied on both feet. The criteria for analyzing footprint patterns obtained using the Harris and Beath footprinting mat presented good reliability and high to excellent inter- and intra-examiner agreement. This method is reliable for analyses involving one or more examiners. Article registered in the Australian New Zealand Clinical Trials Registry (ANZCTR) under the number ACTRN12609000693224.
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Williamson, Rebecca; Carbo, Jorge; Luna, Bernadette; Webbon, Bruce W.
1998-01-01
Wearing impermeable garments for hazardous materials clean up can often present a health and safety problem for the wearer. Even short duration clean up activities can produce heat stress injuries in hazardous materials workers. It was hypothesized that an internal cooling system might increase worker productivity and decrease likelihood of heat stress injuries in typical HazMat operations. Two HazMat protective ensembles were compared during treadmill exercise. The different ensembles were created using two different suits: a Trelleborg VPS suit representative of current HazMat suits and a prototype suit developed by NASA engineers. The two life support systems used were a current technology Interspiro Spirolite breathing apparatus and a liquid air breathing system that also provided convective cooling. Twelve local members of a HazMat team served as test subjects. They were fully instrumented to allow a complete physiological comparison of their thermal responses to the different ensembles. Results showed that cooling from the liquid air system significantly decreased thermal stress. The results of the subjective evaluations of new design features in the prototype suit were also highly favorable. Incorporation of these new design features could lead to significant operational advantages in the future.
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Hepatitis A seroprevalence in patients with chronic viral hepatitis in Konya, Turkey.
Özden, Hale T
2016-03-01
Hepatitis A is among the diseases that can be prevented with vaccination in our time. Acute hepatitis A progresses more severely in individuals with a liver disease. Therefore, patients with a chronic liver disease (because of hepatitis B or hepatitis C) are advised vaccination with the hepatitis A vaccine. This study is aimed to determine the seroprevalence of hepatitis A virus (HAV) antibodies in patients infected with hepatitis C virus or hepatitis B virus in Konya province of Turkey. A total of 537 patients who had chronic viral hepatitis between January 2011 and December 2014 were included in the study. Serum samples were collected from each patient and tested for anti-HAV using the chemiluminescent microparticle immunoassay. The overall seroprevalence of total anti-HAV IgG was 94.2%. The overall prevalence of anti-HAV IgG in patients with chronic hepatitis B virus and hepatitis C virus infection was 97.5 and 93.6%, respectively. Anti-HAV IgG positivity was 97.4% in cirrhotic patients and 93.9% in noncirrhotic individuals. At the end of the study, being older than 40 years and living in a rural area were found to be independent risk factors for anti-HAV IgG seropositivity. In conclusion, we recommend that patients younger than 40 years and/or those living in cities and having a chronic liver disease should be vaccinated with the hepatitis A vaccine.
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Hepatitis A seroprevalence in patients with chronic viral hepatitis in Konya, Turkey
2016-01-01
Aim Hepatitis A is among the diseases that can be prevented with vaccination in our time. Acute hepatitis A progresses more severely in individuals with a liver disease. Therefore, patients with a chronic liver disease (because of hepatitis B or hepatitis C) are advised vaccination with the hepatitis A vaccine. This study is aimed to determine the seroprevalence of hepatitis A virus (HAV) antibodies in patients infected with hepatitis C virus or hepatitis B virus in Konya province of Turkey. Methods A total of 537 patients who had chronic viral hepatitis between January 2011 and December 2014 were included in the study. Serum samples were collected from each patient and tested for anti-HAV using the chemiluminescent microparticle immunoassay. Results The overall seroprevalence of total anti-HAV IgG was 94.2%. The overall prevalence of anti-HAV IgG in patients with chronic hepatitis B virus and hepatitis C virus infection was 97.5 and 93.6%, respectively. Anti-HAV IgG positivity was 97.4% in cirrhotic patients and 93.9% in noncirrhotic individuals. Conclusion At the end of the study, being older than 40 years and living in a rural area were found to be independent risk factors for anti-HAV IgG seropositivity. In conclusion, we recommend that patients younger than 40 years and/or those living in cities and having a chronic liver disease should be vaccinated with the hepatitis A vaccine. PMID:26703930
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Directory of Open Access Journals (Sweden)
Djoko Yuwono
2012-10-01
Full Text Available Virus Hepatitis C dan Hepatitis B merupakan penyebab hepatitis kronik aktif yang dapat berkembang menjadi hepatoselular karsinoma. Untuk mengetahui peranan kedua jenis virus tersebut sebagai penyebab hepatoselular karsinoma, telah dilakukan pemeriksaan HbsAg, anti-VHC dan RNA-VHC pada 17 penderita hepatitis kronis. 19 Pasien hemodialisis dan 198 donor darah PMI. Pemeriksaan HbsAg dilakukan dengan RPHA Cell: pemeriksaan anti-VHC dengan dipstik anti-VHC kit diagnotik produksi NTB Mataram, Lombok. Deteksi RNA-VHC dilakukan dengan teknik RT-PCR, menggunakan primer spesifik untuk daerah 5'NCR. Hasil pemeriksaan menunjukkan bahwa pada penderita hepatitis kronis ditemukan 5 orang (23,5% positif HbsAg dan 1 orang (5,8% anti-VHC. Pada penderita hemodialisis ditemukan 14 orang (73,6% positif anti-VHC, persentase anti-VHC meningkat sesuai dengan meningkatnya frekuensi hemodialisis. Pada donor darah PMI ditemukan 5 orang (2,2% positif HbsAg dan tidak satupun ditemukan anti-VHC positif.
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Experimental study of CT perfusion in hepatitis, hepatic fibrosis and early stage of cirrhosis
International Nuclear Information System (INIS)
Guan Sheng; Zhao Weidong; Zhou Kangrong; Peng Weijun; Mao Jian; Tang Feng; Wang Yong; Cao Guang; Sun Fei
2005-01-01
Objective: To investigate the value of CT perfusion in the early diagnosis of hepatic diffuse disease. Methods: Fourteen male Wistar rats of control group and 14 of test group at stages of hepatitis, hepatic fibrosis, hepatic cirrhosis which were induced with diethylnitrosamine (DEN), were studied with CT perfusion respectively. CT perfusion data of different stages were compared and pathologic analysis were performed. Results: Density-time curves of CT perfusion were satisfactory and all perfusion data could be obtained. During the period of hepatitis developing into early stage of hepatic cirrhosis, hepatic artery flow (HAF) trended to increase in test group, mean transmit time (MTT) prolonged obviously, blood flow (BF) and volume (BV) declined. While in control group, HAF declined slightly, MTT, BV and BF increased. Statistic analysis showed the differences of HAF and MTT at different stages between control and test groups were significant (P<0.05 ); the differences of BV and BF between hepatitis and hepatic cirrhosis, hepatic fibrosis and early stage of hepatic cirrhosis in test group were significant (P<0.05), but no significant difference between hepatitis and hepatic fibrosis. The corresponding pathologic changes at stage of hepatitis was swelling of hepatic cells; sinusoids cap illarization and deposition of collagen in the extravascular Disse's spaces were the main changes relating to hepatic blood perfusion at stage of fibrosis and early stage of cirrhosis. Conclusion: The method of CT scan can reflect some changes of hepatic blood perfusion in rats with hepatitis, hepatic fibrosis and early stage of cirrhosis. The data of CT perfusion, especially the changes should be valuable for clinical early diagnosis, treatment and follow-up. (authors)
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Oliveira, Sabrina A N; Hacker, Mariana A; Oliveira, M Lourdes A; Yoshida, Clara F T; Telles, Paulo R; Bastos, Francisco I
2005-01-01
To measure hepatitis B virus (HBV) infection rates among injection drug users in Rio de Janeiro, Brazil, and to report their knowledge of and attitudes toward hepatitis and HBV vaccination. 609 injection drug users recruited in Rio de Janeiro between 1999 and 2001 answered a questionnaire and were tested for hepatitis B and other blood-borne infections. Questions covered sociodemographic information, alcohol and illicit drug consumption, drug injection and sexual practices, medical history, and knowledge about HIV, AIDS and viral hepatitis. The prevalence of HBV infection was 27.1%, with 3.4% of the sample positive for HbsAg (active infection) and 0.8% positive for anti-HBs (indicating previous HBV vaccination). Most interviewees (81.3%) were aware of at least one form of viral hepatitis and received information from many different sources. In agreement with laboratory findings, 96.7% of the interviewees stated they had never been vaccinated against hepatitis B, but almost all unvaccinated interviewees (97.8%) said they would volunteer to be vaccinated if HBV vaccination were available. Few of the injection drug users surveyed had ever been vaccinated against HBV. Although most were aware of the risks posed by viral hepatitis, this awareness seldom translated into consistent behavioral change. The participants' willingness to be vaccinated against HBV suggests that the implementation of vaccination for this population may help decrease rates of hepatitis B infection.
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... please visit this page: About CDC.gov . Hepatitis Risk Assessment Recommend on Facebook Tweet Share Compartir Viral Hepatitis. Are you at risk? Take this 5 minute Hepatitis Risk Assessment developed ...
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International Nuclear Information System (INIS)
Stevens, C.E.; Taylor, P.E.; Tong, M.J.; Toy, P.T.; Vyas, G.N.; Nair, P.V.; Weissman, J.Y.; Krugman, S.
1987-01-01
A yeast-recombinant hepatitis B vaccine was licensed recently by the Food and Drug administration and is now available. To assess the efficacy of the yeast-recombinant vaccine, the authors administered the vaccine in combination with hepatitis B immune globulin to high-risk newborns. If infants whose mothers were positive for both hepatitis B surface antigen and the e antigen receive no immunoprophylaxis, 70% to 90% become infected with the virus, and almost all become chronic carriers. Among infants in this study who received hepatitis B immune globulin at birth and three 5- + g doses of yeast-recombinant hepatitis B vaccine, only 4.8% became chronic carriers, a better than 90% level of protection and a rate that is comparable with that seen with immune globulin and plasma-derived hepatitis B vaccine. Hepatitis surface antigen and antibodies were detected by radioimmunoassay. These data suggest that, in this high-risk setting, the yeast-recombinant vaccine is as effective as the plasma-derived vaccine in preventing hepatitis B virus infection and the chronic carrier state
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Directory of Open Access Journals (Sweden)
Priscilla J Miranda
2016-07-01
Full Text Available The shallow-sea hydrothermal vents at White Point (WP in Palos Verdes (PV on the southern California coast support microbial mats and provide easily accessed settings in which to study chemolithoautotrophic sulfur cycling. Previous studies have cultured sulfur-oxidizing bacteria from the WP mats; however, almost nothing is known about the in situ diversity and activity of the microorganisms in these habitats. We studied the diversity, micron-scale spatial associations and metabolic activity of the mat community via sequence analysis of 16S rRNA and aprA genes, Fluorescence in situ Hybridization (FISH microscopy and sulfate-reduction rate (SRR measurements. Sequence analysis revealed a diverse group of bacteria, dominated by sulfur cycling gamma-, epsilon- and deltaproteobacterial lineages such as Marithrix, Sulfurovum and Desulfuromusa. FISH microscopy suggests a close physical association between sulfur-oxidizing and sulfur-reducing genotypes, while radiotracer studies showed low, but detectable, SRR. Comparative 16S rRNA gene sequence analyses indicate the WP sulfur vent microbial mat community is similar, but distinct from other hydrothermal vent communities representing a range of biotopes and lithologic settings. These findings suggest a complete biological sulfur cycle is operating in the WP mat ecosystem mediated by diverse bacterial lineages, with some similarity with deep-sea hydrothermal vent communities.
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Energy Technology Data Exchange (ETDEWEB)
Pant, Hem Raj [Department of Bionanosystem Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Department of Engineering Science and Humanities, Institute of Engineering, Pulchowk Campus, Tribhuvan University, Kathmandu (Nepal); Pandeya, Dipendra Raj [Department of Microbiology and Immunology, Institute for Medical Science, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Nam, Ki Taek; Baek, Woo-il [Department of Textile Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Hong, Seong Tshool [Department of Microbiology and Immunology, Institute for Medical Science, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Kim, Hak Yong, E-mail: khy@jbnu.ac.kr [Department of Textile Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of)
2011-05-15
Silver-impregnated TiO{sub 2}/nylon-6 nanocomposite mats exhibit excellent characteristics as a filter media with good photocatalytic and antibacterial properties and durability for repeated use. Silver nanoparticles (NPs) were successfully embedded in electrospun TiO{sub 2}/nylon-6 composite nanofibers through the photocatalytic reduction of silver nitrate solution under UV-light irradiation. TiO{sub 2} NPs present in nylon-6 solution were able to cause the formation of a high aspect ratio spider-wave-like structure during electrospinning and facilitated the UV photoreduction of AgNO{sub 3} to Ag. TEM images, UV-visible and XRD spectra confirmed that monodisperse Ag NPs (approximately 4 nm in size) were deposited selectively upon the TiO{sub 2} NPs of the prepared nanocomposite mat. The antibacterial property of a TiO{sub 2}/nylon-6 composite mat loaded with Ag NPs was tested against Escherichia coli, and the photoactive property was tested against methylene blue. All of the results showed that TiO{sub 2}/nylon-6 nanocomposite mats loaded with Ag NPs are more effective than composite mats without Ag NPs. The prepared material has potential as an economically friendly photocatalyst and water filter media because it allows the NPs to be reused.
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Directory of Open Access Journals (Sweden)
Muhammad Navis Rofii
2014-07-01
Full Text Available Particleboard achieves its overall performance characteristics during hot pressing process. As this process is influenced by several factors, particularly temperature and pressure, it is very important to understand the behavior of both. This study investigates the effects of furnish materials on temperature and vapor pressure behavior inside particleboard mat panels during hot pressing. Strand type particles from hinoki and ring-flaker recycled wood particles were used as furnish for laboratory-scale particleboard panels with a target density of 0.76 g/cm³. Mat panels with a moisture content of about 10% were hot pressed at a platen temperature of 180°C and an initial pressure of 3 MPa until the mat center reached the same temperature as the platen. A press monitoring device (PressMAN Lite was used for detecting the temperature and vapor pressure change in the center of the mat panels. The study showed that the furnish type affected the temperature and vapor behavior inside the mat panels. Particleboard made of hinoki strand resulted in a longer plateau time, a higher plateau temperature and a higher gas pressure generated during hot pressing than those of ring-flaker recycled wood particles. Mixed board resulted in values between those of the two other furnish materials.
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Gangwar, Amit Kumar; Gupta, Ashish; Kedawat, Garima; Kumar, Pawan; Singh, Bhanu Pratap; Singh, Nidhi; Srivastava, Avanish K; Dhakate, Sanjay R; Gupta, Bipin Kumar
2018-05-23
Increasing counterfeiting of important data, currency, stamp papers, branded products etc., has become a major security threat which could lead to serious damage to the global economy. Consequences of such damage are compelling for researchers to develop new high-end security features to address full-proof solutions. Herein, we report a dual mode flexible highly luminescent white security paper and nanotaggants composed of nanophosphors incorporated in polymer matrix to form a nanofiber-based mat for anti-counterfeiting applications. The dual mode nanofibers are fabricated by electrospinning technique by admixing the composite of NaYF 4 :Eu 3+ @NaYF 4 :Yb 3+ , Er 3+ nanophosphors in the polyvinyl alcohol solution. This flexible polymer mat derived from nanofibers appears white in daylight, while emitting strong red (NaYF 4 :Eu 3+ ) and green (NaYF 4 :Yb 3+ , Er 3+ ) colors at excitation wavelengths of 254 nm and 980 nm, respectively. These luminescent nanofibers can also be encrypted as a new class of nanotaggants to protect confidential documents. These obtained results suggest that highly luminescent dual mode polymeric nanofiber-based flexible white security paper and nanotaggants could offer next-generation high-end unique security features against counterfeiting. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.
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Haga, Yuki; Kanda, Tatsuo; Sasaki, Reina; Nakamura, Masato; Nakamoto, Shingo; Yokosuka, Osamu
2015-12-14
Nonalcoholic fatty liver disease (NAFLD) including nonalcoholic steatohepatitis (NASH) is globally increasing and has become a world-wide health problem. Chronic infection with hepatitis B virus or hepatitis C virus (HCV) is associated with hepatic steatosis. Viral hepatitis-associated hepatic steatosis is often caused by metabolic syndrome including obesity, type 2 diabetes mellitus and/or dyslipidemia. It has been reported that HCV genotype 3 exerts direct metabolic effects that lead to hepatic steatosis. In this review, the differences between NAFLD/NASH and viral hepatitis-associated steatosis are discussed.
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Social yoga mats: reinforcing synergy between physical and social activity
DEFF Research Database (Denmark)
Nagargoje, Arun; Sokoler, Tomas; Maybach, Karl
2011-01-01
This paper discusses our early research into the design space for digital technologies that extend the existing synergistic relationship between physical and social activity from fitness centers to the home. We focus on yoga activity for senior citizens and explore the concept of social yoga mats...
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CT diagnosis of hepatic alveolar echinococcosis and evaluation after albendazole chemotherapy
International Nuclear Information System (INIS)
Wu Jingquan; Liu Yuehan; Wang Xiaogen
1998-01-01
Purpose: To analyze the CT features and evaluate albendazole chemotherapy of hepatic alveolar echinococcosis with computed tomography (CT). Methods: Twenty-one patients of hepatic alveolar echincoccosis were diagnosed by epidemiological, clinical, serological tests, and studied with US and CT. Twenty patients were followed up by CT scanning from 1 to 9 years (mean 3.9 years) after albendazole chemotherapy. Results: CT scanning of liver before treatment displayed heterogeneous hypodense lesions, with irregular, obscure contour and calcifications According to CT features, the hepatic lesions were divided into 3 forms: solid mass in 7 cases, pseudocyst in 6 cases and mixed in 8 cases. Three patients had contrast study. The hepatic lesions were not markedly enhanced, but the lesions were seen more clearly and appeared more extensive. In follow-up examination of 20 cases, 4 were apparently cured, 5 improved, 5 stabilized, and 6 cases remained pseudocyst. Conclusion: CT scanning was of value not only for diagnosis of hepatic alveolar echinococcosis, but also useful in evaluation of chemotherapeutic efficacy
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... Clinical Trials Physician Directory HBV Meeting What Is Hepatitis B? What Is Hepatitis B? The ABCs of Viral Hepatitis Liver Cancer and Hepatitis B Hepatitis Delta Coinfection Hepatitis C Coinfection HIV/AIDS ...
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Normal variation of hepatic artery
International Nuclear Information System (INIS)
Kim, Inn; Nam, Myung Hyun; Rhim, Hyun Chul; Koh, Byung Hee; Seo, Heung Suk; Kim, Soon Yong
1987-01-01
This study was an analyses of blood supply of the liver in 125 patients who received hepatic arteriography and abdominal aortography from Jan. 1984 to Dec. 1986 at the Department of Radiology of Hanyang University Hospital. A. Variations in extrahepatic arteries: 1. The normal extrahepatic artery pattern occurred in 106 of 125 cases (84.8%) ; Right hepatic and left hepatic arteries arising from the hepatic artery proper and hepatic artery proper arising from the common hepatic artery. 2. The most common type of variation of extrahepatic artery was replaced right hepatic artery from superior mesenteric artery: 6 of 125 cases (4.8%). B. Variations in intrahepatic arteries: 1. The normal intrahepatic artery pattern occurred in 83 of 125 cases (66.4%). Right hepatic and left hepatic arteries arising from the hepatic artery proper and middle hepatic artery arising from lower portion of the umbilical point of left hepatic artery. 2. The most common variation of intrahepatic arteries was middle hepatic artery. 3. Among the variation of middle hepatic artery; Right, middle and left hepatic arteries arising from the same location at the hepatic artery proper was the most common type; 17 of 125 cases (13.6%)
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Mechanisms of Mindfulness Training: Monitor and Acceptance Theory (MAT)1
Lindsay, Emily K.; Creswell, J. David
2016-01-01
Despite evidence linking trait mindfulness and mindfulness training with a broad range of effects, still little is known about its underlying active mechanisms. Mindfulness is commonly defined as (1) the ongoing monitoring of present-moment experience (2) with an orientation of acceptance. Building on conceptual, clinical, and empirical work, we describe a testable theoretical account to help explain mindfulness effects on cognition, affect, stress, and health outcomes. Specifically, Monitor and Acceptance Theory (MAT) posits that (1), by enhancing awareness of one’s experiences, the skill of attention monitoring explains how mindfulness improves cognitive functioning outcomes, yet this same skill can increase affective reactivity. Second (2), by modifying one’s relation to monitored experience, acceptance is necessary for reducing affective reactivity, such that attention monitoring and acceptance skills together explain how mindfulness improves negative affectivity, stress, and stress-related health outcomes. We discuss how MAT contributes to mindfulness science, suggest plausible alternatives to the account, and offer specific predictions for future research. PMID:27835764
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International Nuclear Information System (INIS)
Wainrib, J.
1978-06-01
The feasibility of developing a modular system approach for the construction of containment mats has been established. The investigative results obtained from a plant used for the modular study has determined that (1) modularization results in a 10-week reduction in the construction schedule critical path over that for the conventional approach, and (2) modularization is cost effective and could result in a savings of approximately $10,700,000. Accordingly, it is recommended that the modular system approach be adopted as standard practice for the construction of containment mats
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... Find Services HIV SERVICES LOCATOR Locator Search Search Hepatitis B & C Topics Hepatitis B Hepatitis C Hepatitis ... Infections Sexually Transmitted Diseases Smoking Women's Health Issues Hepatitis B Virus and Hepatitis C Virus Infection People ...
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Al-Thani, Roda
2014-03-21
The Um Alhool area in Qatar is a dynamic evaporative ecosystem that receives seawater from below as it is surrounded by sand dunes. We investigated the chemical composition, the microbial activity and biodiversity of the four main layers (L1–L4) in the photosynthetic mats. Chlorophyll a (Chl a) concentration and distribution (measured by HPLC and hyperspectral imaging, respectively), the phycocyanin distribution (scanned with hyperspectral imaging), oxygenic photosynthesis (determined by microsensor), and the abundance of photosynthetic microorganisms (from 16S and 18S rRNA sequencing) decreased with depth in the euphotic layer (L1). Incident irradiance exponentially attenuated in the same zone reaching 1% at 1.7-mm depth. Proteobacteria dominated all layers of the mat (24%–42% of the identified bacteria). Anoxygenic photosynthetic bacteria (dominated by Chloroflexus) were most abundant in the third red layer of the mat (L3), evidenced by the spectral signature of Bacteriochlorophyll as well as by sequencing. The deep, black layer (L4) was dominated by sulfate reducing bacteria belonging to the Deltaproteobacteria, which were responsible for high sulfate reduction rates (measured using 35S tracer). Members of Halobacteria were the dominant Archaea in all layers of the mat (92%–97%), whereas Nematodes were the main Eukaryotes (up to 87%). Primary productivity rates of Um Alhool mat were similar to those of other hypersaline microbial mats. However, sulfate reduction rates were relatively low, indicating that oxygenic respiration contributes more to organic material degradation than sulfate reduction, because of bioturbation. Although Um Alhool hypersaline mat is a nutrient-limited ecosystem, it is interestingly dynamic and phylogenetically highly diverse. All its components work in a highly efficient and synchronized way to compensate for the lack of nutrient supply provided during regular inundation periods.
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Hepatitis C: Sex and Sexuality
... with Hepatitis » Sex and Sexuality: Entire Lesson Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For ... hepatitis C virus through sex. Can you pass hepatitis C to a sex partner? Yes, but it ...
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Hepatitis C: Diet and Nutrition
... with Hepatitis » Daily Living: Diet and Nutrition Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For ... have high cholesterol and have fatty liver. How hepatitis C affects diet If you have hepatitis, you ...
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Moyer, C. L.; Fullerton, H.
2013-12-01
Iron is the fourth most abundant element in the Earth's crust and is potentially one of the most abundant energy sources on the earth as an electron donor for chemolithoautotrophic growth coupled to Fe(II) oxidation. Despite the rapid abiotic oxidation rate of iron, many microbes have adapted to feeding off this fleeting energy source. One such bacterial class is the Zetaproteobacteria. Iron-dominated microbial mat material was collected with a small-scale syringe sampler from Loihi Seamount, Hawaii. From this sample, gDNA was extracted and prepared for paired-end Illumina sequencing. Reconstruction of SSU rDNA genes using EMERGE allowed for comparison to previous SSU rDNA surveys. Clone libraries and qPCR show these microbial mats to be dominated by Zetaproteobacteria. Results from our in silico reconstruction confirm these initial findings. RDP classification of the EMERGE reconstructed sequences resulted in 44% of the community being identified as Zetaproteobacteria. The most abundant SSU rDNA has 99% similarity to Zeta OTU-2, and only a 94% similarity to M. ferrooxidans PV-1. Zeta OTU-2 has been shown to be the most cosmopolitan population in iron-dominated hydrothermal systems from across Pacific Ocean. Metagenomic assembly has resulted in many contigs with high identity to M. ferrooxidans as identified, by BLAST. However, with large differences in SSU rRNA similarity, M. ferrooxidans PV-1 is not an adequate reference. Current work is focusing on reconstruction of the dominant microbial mat member, without the use of a reference genome through an iterative assembly approach. The resulting 'pan-genome' will be compared to other Zetaproteobacteria (at the class level) and the functional ecology of this cosmopolitan microbial mat community member will be extrapolated. Thus far, we have detected multiple housekeeping genes involved in DNA replication, transcription and translation. The most abundant metabolic gene we have found is Aconitase, a key enzyme in the
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Directory of Open Access Journals (Sweden)
Raymundo Paraná
2002-06-01
Full Text Available O vírus da hepatite E (VHE é o segundo vírus de transmissão fecal-oral com hepatotropismo confirmado, após o vírus da hepatite A. As grandes epidemias de hepatite das décadas de 50 e 60 na Índia foram causadas pelo VHE. Observaram-se surtos da infecção na África Central, América Latina, Oriente Médio e Repúblicas independentes da ex-União Soviética. O quadro clínico da doença assemelha-se ao de outras hepatites virais. Não há casos descritos de hepatite E crônicas. Cerca de 20% das mulheres que adquirem a doença durante a gravidez desenvolvem formas graves, com insuficiência hepática fulminante. Confirma-se o diagnóstico quando se encontra no soro anticorpos (método de ELISA das classes IgM (fase aguda e/ou IgG (curados. O imunoblot e o PCR-RNA podem ser usados quando necessário. Não há tratamento específico. O uso de imunoglobulina hiperimune tem sido aconselhado por alguns autores. A prevenção se faz pelos cuidados higiênicos e dietéticos habituais. Não há vacina eficaz contra a doença.Hepatitis E virus (HEV is the second most frequent hepatotropic virus transmitted via fecal-oral route, following closely behind hepatitis A virus. The great epidemics of hepatitis described during the 50s and 60s, in India, were caused by this virus. Epidemic bursts have also been described in Central Africa, Latin America, Middle East and in the independent Republics of the ex-Soviet Union. The clinical features of the disease do not differ from those reported for other viral hepatitides. There have been no cases of chronic hepatitis E reported. Around 20% of women infected during pregnancy develop a severe form of hepatitis which courses to liver failure. Diagnosis of hepatitis is confirmed when antibodies (using ELISA of the IgM class (acute phase and/or IgG (infected and cured are found in the serum. Immunoblot and PCR-RNA may be used as necessary. There is no specific treatment for hepatitis E. Hyperimmune serum has
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Does chronic hepatitis B infection affect the clinical course of acute hepatitis A?
Shin, Su Rin; Moh, In Ho; Jung, Sung Won; Kim, Jin Bae; Park, Sang Hoon; Kim, Hyoung Su; Jang, Myung Kuk; Lee, Myung Seok
2013-01-01
The impact of chronic hepatitis B on the clinical outcome of acute hepatitis A remains controversial. The aim of present study was to evaluate the clinical characteristics of acute hepatitis A in cases with underlying chronic hepatitis B compared to cases of acute hepatitis A alone. Data on 758 patients with acute hepatitis A admitted at two university-affiliated hospitals were reviewed. Patients were classified into three groups: group A, patients with both acute hepatitis A and underlying chronic hepatitis B (n = 27); group B, patients infected by acute hepatitis A alone whose sexes and ages were matched with patients in group A (n = 54); and group C, patients with acute hepatitis A alone (n = 731). None of the demographic features of group A were significantly different from those of group B or C, except for the proportion of males and body weight, which differed from group C. When comparing to group B, clinical symptoms were more frequent, and higher total bilirubin and lower albumin levels were observed in group A. When comparing to group C, the albumin levels were lower in group A. There were no differences in the duration of hospital stay, occurrence of acute kidney injury, acute liver failure, prolonged cholestasis, or relapsing hepatitis. This study revealed that clinical symptoms and laboratory findings were less favorable for patients with acute hepatitis A and chronic hepatitis B compared to those with acute hepatitis A alone. However, there were no differences in fatal outcomes or serious complications. Copyright © 2012 Wiley Periodicals, Inc.
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Burges Watson, Duika; Adams, Jean; Azevedo, Liane B; Haighton, Catherine
2016-07-20
Physical activity is critical to improving health and well-being in children. Quantitative studies have found a decline in activity in the transition from primary to secondary education. Exergames (active video games) might increase physical activity in adolescents. In January 2011 exergame dance mat systems were introduced in to all secondary schools across two local authority districts in the UK. We performed a quasi-experimental evaluation of a natural experiment using a mixed methods design. The quantitative findings from this work have been previously published. The aim of this linked qualitative study was to explore the implementation of the dance mat scheme and offer insights into its uptake as a physical activity intervention. Embedded qualitative interviews at baseline and 12 month follow-up with purposively selected physical education teachers (n = 20) and 25 focus groups with a convenience sample of pupils (n = 120) from five intervention schools were conducted. Analysis was informed by sociology of translation approach. At baseline, participants (both teachers and pupils) reported different expectations about the dance mats and how they could be employed. Variation in use was seen at follow-up. In some settings they were frequently used to engage hard to reach groups of pupils. Overall, the dance mats were not used routinely to increase physical activity. However there were other unanticipated benefits to pupils such as improved reaction time, co-ordination and mathematic skills. The use of dance mats was limited in routine physical education classes because of contextual issues (school/government policy) technological failures (batteries/updates) and because of expectations about how and where they could be used. Our linked quantitative study (previously published) suggested that the dance mats were not particularly effective in increasing physical activity, but the qualitative results (reported here) show that the dance mats were not used
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Directory of Open Access Journals (Sweden)
Duika Burges Watson
2016-07-01
Full Text Available Abstract Background Physical activity is critical to improving health and well-being in children. Quantitative studies have found a decline in activity in the transition from primary to secondary education. Exergames (active video games might increase physical activity in adolescents. In January 2011 exergame dance mat systems were introduced in to all secondary schools across two local authority districts in the UK. We performed a quasi-experimental evaluation of a natural experiment using a mixed methods design. The quantitative findings from this work have been previously published. The aim of this linked qualitative study was to explore the implementation of the dance mat scheme and offer insights into its uptake as a physical activity intervention. Methods Embedded qualitative interviews at baseline and 12 month follow-up with purposively selected physical education teachers (n = 20 and 25 focus groups with a convenience sample of pupils (n = 120 from five intervention schools were conducted. Analysis was informed by sociology of translation approach. Results At baseline, participants (both teachers and pupils reported different expectations about the dance mats and how they could be employed. Variation in use was seen at follow-up. In some settings they were frequently used to engage hard to reach groups of pupils. Overall, the dance mats were not used routinely to increase physical activity. However there were other unanticipated benefits to pupils such as improved reaction time, co-ordination and mathematic skills. The use of dance mats was limited in routine physical education classes because of contextual issues (school/government policy technological failures (batteries/updates and because of expectations about how and where they could be used. Conclusions Our linked quantitative study (previously published suggested that the dance mats were not particularly effective in increasing physical activity, but the qualitative
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Inorganic Nanoparticle as a Carrier for Hepatitis B Viral Capsids
Dekhtyar, Yu.; Romanova, M.; Kachanovska, A.; Skrastiņa, D.; Reinhofa, R.; Pumpens, P.; Patmalnieks, A.
Virus like particles (VLP) are used to transport immune response-modulating agents to target cells to treat them. In order to deliver a high concentration of VLP to the cell, a number of VLP can be attached to a nanoparticle to be used as a nanolorry. In this study, SiO2 nanoparticles were attached to Hepatitis B VLP. Spectrophotometry measurements, electron, and fluorescent microscopy evidence showed that the SiO2 - Hepatitis B VLP complexes were formed.
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Energy Technology Data Exchange (ETDEWEB)
Spasova, M.; Manolova, N. [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 103A, BG-1113 Sofia (Bulgaria); Markova, N. [Institute of Microbiology, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 26, BG-1113 Sofia (Bulgaria); Rashkov, I., E-mail: rashkov@polymer.bas.bg [Laboratory of Bioactive Polymers, Institute of Polymers, Bulgarian Academy of Sciences, Acad. G. Bonchev St, bl. 103A, BG-1113 Sofia (Bulgaria)
2016-02-15
Graphical abstract: - Highlights: • New PVDF and PVDF-HFP nanofibers decorated with ZnO nanoparticles and a model drug. • The nanofibrous materials were fabricated by one-pot electrospinning. • The obtained materials are superhybrophobic and possess antibacterial properties. - Abstract: Superhydrophobic nanofibrous materials of poly(vinylidene fluoride) (PVDF) and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) were prepared by one-pot electrospinning technique. The mats were decorated with ZnO nanoparticles with silanized surface and a model drug – 5-chloro-8-hydroxyquinolinol (5Cl8HQ). The obtained hybrid nanofibrous materials were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), contact angle measurements, mechanical and microbiological tests. The results showed that the incorporation of ZnO nanoparticles into PVDF and PVDF-HFP nanofibers increased the hydrophobicity (contact angle 152°), improved the thermal stability and imparted to the nanofibrous materials anti-adhesive and antimicrobial properties. The mats containing the model drug possessed antibacterial activity against Escherichia coli and Staphylococcus aureus. The results suggested that the obtained hybrid mats could find potential biomedical applications requiring antibacterial and anti-biofouling properties.
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Flygande mat - kabinpersonals måltidssituation
Johansson, Johanna; Hugosson, Ellen
2015-01-01
Inledning Yrket som kabinanställd inom flyget präglas av serviceanda och ansvar för passagerares säkerhet. Arbetsmiljön innebär fysiska påfrestningar vad gäller till exempel kabintryck och låg syrenivå. Mat och måltider intas under olika tider på dygnet och infaller sällan på normala måltidstider. Kabinpersonalens måltider regleras av regler, avtal och policyer rörande arbetstidens längd. Syfte Syftet var att undersöka kabinpersonalens måltider under arbetstid, med fokus på riktlinjer och pol...
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Sequence analysis of Maturase K (matK): A chloroplast-encoding ...
African Journals Online (AJOL)
The application and utilization of sequence data has been found very informative in the characterization and phylogenetic relationship of different crops species. This study aimed to use bioinformatics tools to characterize the matK gene in some selected legumes with special reference to pigeon pea [cajanus cajan ...
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How Hepatitis D Virus Can Hinder the Control of Hepatitis B Virus
Xiridiou, M.; Borkent-Raven, B.; Hulshof, J.; Wallinga, J.
2009-01-01
Background: Hepatitis D (or hepatitis delta) virus is a defective virus that relies on hepatitis B virus (HBV) for transmission; infection with hepatitis D can occur only as coinfection with HBV or superinfection of an existing HBV infection. Because of the bond between the two viruses, control
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Microbiological diagnostics of viral hepatitis
HASDEMİR, Ufuk
2016-01-01
Viral hepatitis is an infection that primarily affects the liverbut may also have systemic clinical manifestations. The vastmajority of viral hepatitis are caused by one of five hepatotropicviruses: hepatitis A virus (HAV), hepatitis B virus (HBV),hepatitis C virus (HCV), hepatitis D (delta) virus (HDV), andhepatitis E virus (HEV) (Table I) [1]. HBV, HCV, and HDValso cause chronic hepatitis, whereas HAV does not. HEVcauses acute hepatitis in normal hosts but can cause protractedand chronic he...
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Liu, Yaowen; Lu, Jinfu; Li, Huinan; Wei, Jiaojun; Li, Xiaohong
2015-01-01
Although engineered blood vessels have seen important advances during recent years, proper mechanical strength and vasoactivity remain unsolved problems. In the current study, micropatterned fibrous mats were created to load smooth muscle cells (SMC), and a co-culture with endothelial cells (EC) was established through overlaying on an EC-loaded flat fibrous mat to mimic the layered structure of a blood vessel. A preferential distribution of SMC was determined in the patterned regions throughout the fibrous scaffolds, and aligned fibers in the patterned regions provided topological cues to guide the orientation of SMC with intense actin filaments and extracellular matrix (ECM) production in a circumferential direction. Plasmid DNA encoding basic fibroblast growth factors and vascular endothelial growth factor were integrated into electrospun fibers as biological cues to promote SMC infiltration into fibrous mats, and the viability and ECM production of both EC and SMC. The layered fibrous mats with loaded EC and SMC were wrapped into a cylinder, and engineered vessels were obtained with compact EC and SMC layers after co-culture for 3 months. Randomly oriented ECM productions of EC formed a continuous endothelium covering the entire lumenal surface, and a high alignment of ECM was shown in the circumferential direction of SMC layers. The tensile strength, strain at failure and suture retention strength were higher than those of the human femoral artery, and the burst pressure and radial compliance were in the same range as the human saphenous vein, indicating potential as blood vessel substitutes for transplantation in vivo. Thus, the establishment of topographical cues and biochemical signals in fibrous scaffolds demonstrates advantages in modulating cellular behavior and organization found in complex multicellular tissues. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
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Investigation of VEGGIE Root Mat
Subbiah, Arun M.
2013-01-01
VEGGIE is a plant growth facility that utilizes the phenomenon of capillary action as its primary watering system. A cloth made of Meta Aramid fiber, known as Nomex is used to wick water up from a reservoir to the bottom of the plants roots. This root mat system is intended to be low maintenance with no moving parts and requires minimal crew interface time. Unfortunately, the water wicking rates are inconsistent throughout the plant life cycle, thus causing plants to die. Over-wicking of water occurs toward the beginning of the cycle, while under-wicking occurs toward the middle. This inconsistency of wicking has become a major issue, drastically inhibiting plant growth. The primary objective is to determine the root cause of the inconsistent wicking through experimental testing. Suspect causes for the capillary water column to break include: a vacuum effect due to a negative pressure gradient in the water reservoir, contamination of material due to minerals in water and back wash from plant fertilizer, induced air bubbles while using syringe refill method, and material limitations of Nomex's ability to absorb and retain water. Experimental testing will be conducted to systematically determine the cause of under and over-wicking. Pressure gages will be used to determine pressure drop during the course of the plant life cycle and during the water refill process. A debubbler device will be connected to a root mat in order to equalize pressure inside the reservoir. Moisture and evaporation tests will simultaneously be implemented to observe moisture content and wicking rates over the course of a plant cycle. Water retention tests will be performed using strips of Nomex to determine materials wicking rates, porosity, and absorptivity. Through these experimental tests, we will have a better understanding of material properties of Nomex, as well as determine the root cause of water column breakage. With consistent test results, a forward plan can be achieved to resolve
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[Autoimmune hepatitis: Immunological diagnosis].
Brahim, Imane; Brahim, Ikram; Hazime, Raja; Admou, Brahim
2017-11-01
Autoimmune hepatopathies (AIHT) including autoimmune hepatitis (AIH), primary biliary cirrhosis (PBC), primary sclerosing cholangitis (PSC) and autoimmune cholangitis (AIC), represent an impressive entities in clinical practice. Their pathogenesis is not perfectly elucidated. Several factors are involved in the initiation of hepatic autoimmune and inflammatory phenomena such as genetic predisposition, molecular mimicry and/or abnormalities of T-regulatory lymphocytes. AIHT have a wide spectrum of presentation, ranging from asymptomatic forms to severe acute liver failure. The diagnosis of AIHT is based on the presence of hyperglobulinemia, cytolysis, cholestasis, typical even specific circulating auto-antibodies, distinctive of AIH or PBC, and histological abnormalities as well as necrosis and inflammation. Anti-F actin, anti-LKM1, anti-LC1 antibodies permit to distinguish between AIH type 1 and AIH type 2. Anti-SLA/LP antibodies are rather associated to more severe hepatitis, and particularly useful for the diagnosis of seronegative AIH for other the antibodies. Due to the relevant diagnostic value of anti-M2, anti-Sp100, and anti-gp210 antibodies, the diagnosis of PBC is more affordable than that of PSC and AIC. Based on clinical data, the immunological diagnosis of AIHT takes advantage of the various specialized laboratory techniques including immunofluorescence, immunodot or blot, and the Elisa systems, provided of a closer collaboration between the biologist and the physician. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
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production and cost of cold patch road mats with bitumen extracted
African Journals Online (AJOL)
Jamiu
This paper reports the production of bituminous road mats with bitumen sourced from the Nigerian Tar sand, recycled .... scrap tires are produced every year, which makes the disposal of ..... particles will be round or nearly round and will pass.
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Enan, M R; Ahamed, A
2014-02-14
The cultivated date palm is the most agriculturally important species of the Arecaceae family. The standard chloroplast DNA barcode for land plants recommended by the Consortium for the Barcode of Life plant working group needs to be evaluated for a wide range of plant species. Therefore, we assessed the potential of the matK and rpoC1 markers for the authentication of date cultivars. There is not one universal method to authenticate date cultivars. In this study, 11 different date cultivars were sequenced and analyzed for matK and rpoC1 genes by using bioinformatic tools to establish a cultivar-specific molecular monogram. The chloroplast matK marker was more informative than the rpoC1 chloroplast DNA markers. Phylogenetic trees were constructed on the basis of the matK and rpoC1 sequences, and the results suggested that matK alone or in combination with rpoC1 can be used for determining the levels of genetic variation and for barcoding.
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Charpy V, an application in Mat lab
International Nuclear Information System (INIS)
Castillo M, J.A.; Torres V, M.
2003-01-01
The obtained results with the system Charpy V V 1 designed in Mat lab for the estimate of parameters of three mathematical models are shown. The adjustment of data is used to determine the fracture energy, the lateral expansion and the percentage of ductility of steels coming from the reactor vessels of Laguna Verde, Veracruz. The data come from test tubes type Charpy V of irradiated material and not irradiated. To verify our results they were compared with those obtained by General Electric of data coming from the Laguna Verde nuclear power plant. (Author)
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How compressible is recombinant battery separator mat?
Energy Technology Data Exchange (ETDEWEB)
Pendry, C. [Hollingsworth and Vose, Postlip Mills Winchcombe (United Kingdom)
1999-03-01
In the past few years, the recombinant battery separator mat (RBSM) for valve-regulated lead/acid (VRLA) batteries has become the focus of much attention. Compression, and the ability of microglass separators to maintain a level of `springiness` have helped reduce premature capacity loss. As higher compressions are reached, we need to determine what, if any, damage can be caused during the assembly process. This paper reviews the findings when RBSM materials, with different surface areas, are compressed under forces up to 500 kPa in the dry state. (orig.)
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Feature Hepatitis: The Dangers of Hepatitis: What you should know from A to E
... Navigation Bar Home Current Issue Past Issues Feature Hepatitis The Dangers of Hepatitis: What you should know from A to E ... drugs. In some cases, hepatitis lasts a lifetime. Hepatitis: Acute or Chronic? Acute hepatitis is the initial ...
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Hepatitis C virus core protein induces hepatic steatosis via Sirt1-dependent pathway.
Zhang, Chuanhai; Wang, Jingjing; Zhang, Hanlin; Liu, Shunai; Lee, Hyuek Jong; Jin, Wanzhu; Cheng, Jun
2018-05-01
Hepatic steatosis is a common feature of patients with chronic hepatitis C. Previous reports have shown that the overexpression of hepatitis C virus core-encoding sequences (hepatitis C virus genotypes 3a and 1b) significantly induces intracellular triglyceride accumulation. However, the underlying mechanism has not yet been revealed. To investigate whether Sirt1 is involved in hepatitis C virus-mediated hepatic steatosis, the overexpression of hepatitis C virus core 1b protein and Sirt1 and the knockdown of Sirt1 in HepG2 cells were performed. To confirm the results of the cellular experiment liver-specific Sirt1 KO mice with lentivirus-mediated hepatitis C virus core 1b overexpression were studied. Our results show that hepatitis C virus core 1b protein overexpression led to the accumulation of triglycerides in HepG2 cells. Notably the expression of PPARγ2 was dramatically increased at both the mRNA and protein levels by hepatitis C virus core 1b overexpression. The protein expression of Sirt1 is an upstream regulator of PPARγ2 and was also significantly increased after core 1b overexpression. In addition, the overexpression or knockdown of Sirt1 expression alone was sufficient to modulate p300-mediated PPARγ2 deacetylation. In vivo studies showed that hepatitis C virus core protein 1b-induced hepatic steatosis was attenuated in liver-specific Sirt1 KO mice by downregulation of PPARγ2 expression. Sirt1 mediates hepatitis C virus core protein 1b-induced hepatic steatosis by regulation of PPARγ2 expression. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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... Links Patient Resources For Health Professionals Subscribe Search Hepatitis B Testing Send Us Your Feedback Choose Topic At ... Known As HBV Tests Hep B anti-HBs Hepatitis B Surface Antibody HBsAg Hepatitis B Surface Antigen HBeAg ...
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Sulfate Reduction and Thiosulfate Transformations in a Cyanobacterial Mat during a Diel Oxygen Cycle
DEFF Research Database (Denmark)
JØRGENSEN, BB
1994-01-01
Bacterial sulfate reduction and transformations of thiosulfate were studied with radiotracers in a Microcoleus chthono-plastes-dominated microbial mat growing in a hypersaline pond at the Red Sea. The study showed how a diel cycle of oxygen evolution affected respiration by sulfate-reducing bacte......Bacterial sulfate reduction and transformations of thiosulfate were studied with radiotracers in a Microcoleus chthono-plastes-dominated microbial mat growing in a hypersaline pond at the Red Sea. The study showed how a diel cycle of oxygen evolution affected respiration by sulfate......-reducing bacteria and the metabolism of thiosulfate through oxidative and reductive pathways. Sulfate reduction occurred in both oxic and anoxic layers of the mat and varied diurnally, apparently according to temperature rather than to oxygen. Time course experiments showed that the radiotracer method...... underestimated sulfate reduction in the oxic zone due to rapid reoxidation of the produced sulfide. Extremely high reduction rates of up to 10 mu mol cm(-3) d(-1) were measured just below the euphotic zone. Although thiosulfate was simultaneously oxidized, reduced and disproportionated by bacteria in all layers...
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International Nuclear Information System (INIS)
Al-Thukair, A.
1993-01-01
Remote sensing techniques and ground truth verification were used to provide information on algal mat locations and damage intensity caused by the oil spill. Pre and post oil spill satellite images, ground truth assessment were compared for damage evaluation. Locations and sites status (heavily oiled, recovering, and no algal mats) were conveyed in maps. Recovered sites are found in Abu Ali and Tanajib areas. However, recovery seems to be slower in Abu Ali area as compared to Tanajib. Different types and formations of algal mats were found in both areas. This differentiation is more likely to be attributable to coastal topography and tide regimes
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International Nuclear Information System (INIS)
Konstam, M.A.; Novelline, R.A.; Athanasoulis, C.A.
1979-01-01
In a patient undergoing selective hepatic arteriography for suspected liver trauma, a nonopacified area of the liver, initially thought to represent a hepatic hematoma, was later discovered to be due to the presence of an accessory right hepatic artery arising from the superior mesenteric artery. This case illustrates the need for a search for aberrant vasculature whenever a liver hematoma is suspected on the basis of a selective hepatic arteriogram. (orig.) [de
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Abed, Raeid M M; Kohls, Katharina; de Beer, Dirk
2007-06-01
The effects of salinity fluctuation on bacterial diversity, rates of gross photosynthesis (GP) and oxygen consumption in the light (OCL) and in the dark (OCD) were investigated in three submerged cyanobacterial mats from a transect on an intertidal flat. The transect ran 1 km inland from the low water mark along an increasingly extreme habitat with respect to salinity. The response of GP, OCL and OCD in each sample to various salinities (65 per thousand, 100 per thousand, 150 per thousand and 200 per thousand) were compared. The obtained sequences and the number of unique operational taxonomic units showed clear differences in the mats' bacterial composition. While cyanobacteria decreased from the lower to the upper tidal mat, other bacterial groups such as Chloroflexus and Cytophaga/Flavobacteria/Bacteriodetes showed an opposite pattern with the highest dominance in the middle and upper tidal mats respectively. Gross photosynthesis and OCL at the ambient salinities of the mats decreased from the lower to the upper tidal zone. All mats, regardless of their tidal location, exhibited a decrease in areal GP, OCL and OCD rates at salinities > 100 per thousand. The extent of inhibition of these processes at higher salinities suggests an increase in salt adaptation of the mats microorganisms with distance from the low water line. We conclude that the resilience of microbial mats towards different salinity regimes on intertidal flats is accompanied by adjustment of the diversity and function of their microbial communities.
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The Ububele Baby Mat Service – A primary preventative mental ...
African Journals Online (AJOL)
The Ububele Baby Mat Service is a community-based, parent–infant mental health intervention offered at five primary health care clinics in Alexandra Township, in Johannesburg. The aim of the intervention is to promote healthy caregiver-infant attachments. There has been a steady increase in the number of mother-baby ...
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MATS--Management Accounting Tutorial System. Version 1.0. Project Documentation.
Wardle, Andrew; O'Connor, Rodric
The Management Accounting Tutorial System (MATS) is a management accounting database for a carpet manufacturing company. The system allows the display and output of monthly activities, and is intended to provide a means of illustrating the main topics of the second year management accounting course at Manchester University. The system itself…
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MATS--Management Accounting Tutorial System. Version 1.0. User Guide.
Wardle, Andrew; O'Connor, Rodric
The Management Accounting Tutorial System (MATS) is a management accounting database for a carpet manufacturing company. The system allows the display and output of monthly activities, and is intended to provide a means of illustrating the main topics of the second year management accounting course at Manchester University. The system itself…
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Seroprevalence and risk factors of Hepatitis B and Hepatitis C ...
African Journals Online (AJOL)
Undertaking blood transfusion, tattooing and sharing of needles were associated with hepatitis C infection (P=0.001). HBV was not associated with any of the risk factors (P>0.05). Conclusion: Our findings suggest a high prevalence of hepatitis B and hepatitis C among pregnant women; blood transfusion, tattooing and ...
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Detection of defects in formed sheet metal using medial axis transformation
Murmu, Naresh C.; Velgan, Roman
2003-05-01
In the metal forming processes, the sheet metals are often prone to various defects such as thinning, dents, wrinkles etc. In the present manufacturing environments with ever increasing demand of higher quality, detecting the defects of formed sheet metal using an effective and objective inspection system is the foremost norm to remain competitive in market. The defect detection using optical techniques aspire to satisfy its needs to be non-contact and fast. However, the main difficulties to achieve this goal remain essentially on the development of efficient evaluation technique and accurate interpretation of extracted data. The defect like thinning is detected by evaluating the deviations of the thickness in the formed sheet metal against its nominal value. The present evaluation procedure for determination of thickness applied on the measurements data is not without deficiency. To improve this procedure, a new evaluation approach based on medial axis transformation is proposed here. The formed sheet metals are digitized using fringe projection systems in different orientations, and afterwards registered into one coordinate frame. The medial axis transformation (MAT) is applied on the point clouds, generating the point clouds of MAT. This data is further processed and medial surface is determined. The thinning defect is detected by evaluating local wall thickness and other defects like wrinkles are determined using the shape recognition on the medial surface. The applied algorithm is simple, fast and robust.
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Lower doses venlafaxine-associated toxic hepatitis in a patient with chronic hepatitis
International Nuclear Information System (INIS)
Sencan, I.; Sahin, I.; Ozcetin, A.
2003-01-01
Toxic hepatitis is observed with high doses of Venlafaxine. But toxic hepatitis has not been yet reported at lower doses of Venlafaxine such as 37.5 mg per day. In this case report, a case of Venlafaxine associated toxic hepatitis with lower doses in patient with history of chronic hepatitis is presented. We suggest that liver function should be regularly monitored in patients with history of chronic hepatitis receiving Venlafaxine even at lower doses and even when their liver enzymes are normal. (author)
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Energy Technology Data Exchange (ETDEWEB)
Sinis Fernandez, F.; Rubio guzman, B.; Gonzalez Abadias, A. I.
2011-07-01
This article describes the content of the DIRECT-MAT (Dismantling and Recycling for road Materials) project. the DIRECT MAT project objectives consist of sharing and disseminating, at the European scale, national knowledge and field practices regarding the dismantling and recycling of road and road related materials, for the benefit of all European countries. Road material recycling processes have previously been studied in national research projects in the last years; unfortunately, the results of those projects almost never benefit other European countries. This is especially true for the newer Member States. The DIRECT-MAT project, within 7{sup t}h Framework Programme, is a three year project starting in 2009, and is comparised of 20 partners from 15 participating countries. to reach the aims of the project, a WEB database will be created to compile and display the extensive and already validated research and job site data and a set of Best Practices Guides on dismantling and recycling of different types of materials will be issued. Finally, guidelines will be proposed to ensure database updating, including the results of future researches. (Author) 6 refs.
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Hepatic p38α regulates gluconeogenesis by suppressing AMPK.
Jing, Yanyan; Liu, Wei; Cao, Hongchao; Zhang, Duo; Yao, Xuan; Zhang, Shengjie; Xia, Hongfeng; Li, Dan; Wang, Yu-cheng; Yan, Jun; Hui, Lijian; Ying, Hao
2015-06-01
It is proposed that p38 is involved in gluconeogenesis, however, the genetic evidence is lacking and precise mechanisms remain poorly understood. We sought to delineate the role of hepatic p38α in gluconeogenesis during fasting by applying a loss-of-function genetic approach. We examined fasting glucose levels, performed pyruvate tolerance test, imaged G6Pase promoter activity, as well as determined the expression of gluconeogenic genes in mice with a targeted deletion of p38α in liver. Results were confirmed both in vivo and in vitro by using an adenoviral dominant-negative form of p38α (p38α-AF) and the constitutively active mitogen-activated protein kinase 6, respectively. Adenoviral dominant-negative form of AMP-activated protein kinase α (DN-AMPKα) was employed to test our proposed model. Mice lacking hepatic p38α exhibited reduced fasting glucose level and impaired gluconeogenesis. Interestingly, hepatic deficiency of p38α did not result in an alteration in CREB phosphorylation, but led to an increase in AMPKα phosphorylation. Adenoviral DN-AMPKα could abolish the effect of p38α-AF on gluconeogenesis. Knockdown of up-steam transforming growth factor β-activated kinase 1 decreased the AMPKα phosphorylation induced by p38α-AF, suggesting a negative feedback loop. Consistently, inverse correlations between p38 and AMPKα phosphorylation were observed during fasting and in diabetic mouse models. Importantly, adenoviral p38α-AF treatment ameliorated hyperglycemia in diabetic mice. Our study provides evidence that hepatic p38α functions as a negative regulator of AMPK signaling in maintaining gluconeogenesis, dysregulation of this regulatory network contributes to unrestrained gluconeogenesis in diabetes, and hepatic p38α could be a drug target for hyperglycemia. Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
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Estrella Alcamán, María; Fernandez, Camila; Delgado, Antonio; Bergman, Birgitta; Díez, Beatriz
2015-10-01
Cyanobacteria from Subsection V (Stigonematales) are important components of microbial mats in non-acidic terrestrial hot springs. Despite their diazotrophic nature (N2 fixers), their impact on the nitrogen cycle in such extreme ecosystems remains unknown. Here, we surveyed the identity and activity of diazotrophic cyanobacteria in the neutral hot spring of Porcelana (Northern Patagonia, Chile) during 2009 and 2011-2013. We used 16S rRNA and the nifH gene to analyze the distribution and diversity of diazotrophic cyanobacteria. Our results demonstrate the dominance of the heterocystous genus Mastigocladus (Stigonematales) along the entire temperature gradient of the hot spring (69-38 °C). In situ nitrogenase activity (acetylene reduction), nitrogen fixation rates (cellular uptake of (15)N2) and nifH transcription levels in the microbial mats showed that nitrogen fixation and nifH mRNA expression were light-dependent. Nitrogen fixation activities were detected at temperatures ranging from 58 °C to 46 °C, with maximum daily rates of 600 nmol C2H4 cm(-2) per day and 94.1 nmol N cm(-2) per day. These activity patterns strongly suggest a heterocystous cyanobacterial origin and reveal a correlation between nitrogenase activity and nifH gene expression during diurnal cycles in thermal microbial mats. N and C fixation in the mats contributed ~3 g N m(-2) per year and 27 g C m(-2) per year, suggesting that these vital demands are fully met by the diazotrophic and photoautotrophic capacities of the cyanobacteria in the Porcelana hot spring.
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Boks, Marije N; Tiebosch, Anton T; van der Waaij, Laurens A
2017-11-01
The use of anabolic steroids is prevalent in recreational athletes. This case report describes a young amateur bodybuilder who was referred to our outpatient clinic with jaundice and loss of appetite due to cholestatic hepatitis. Additional tests including a liver biopsy made it likely that the hepatitis was caused by the injectable anabolic steroid trenbolone enanthate. Cholestatic hepatitis may not be limited to the use of oral anabolic-androgenic steroids, as is widely assumed. Therefore, and because of other side effects, the recreational use of all forms of anabolic steroids should be discouraged.
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Reconstruction of hyperspectral image using matting model for classification
Xie, Weiying; Li, Yunsong; Ge, Chiru
2016-05-01
Although hyperspectral images (HSIs) captured by satellites provide much information in spectral regions, some bands are redundant or have large amounts of noise, which are not suitable for image analysis. To address this problem, we introduce a method for reconstructing the HSI with noise reduction and contrast enhancement using a matting model for the first time. The matting model refers to each spectral band of an HSI that can be decomposed into three components, i.e., alpha channel, spectral foreground, and spectral background. First, one spectral band of an HSI with more refined information than most other bands is selected, and is referred to as an alpha channel of the HSI to estimate the hyperspectral foreground and hyperspectral background. Finally, a combination operation is applied to reconstruct the HSI. In addition, the support vector machine (SVM) classifier and three sparsity-based classifiers, i.e., orthogonal matching pursuit (OMP), simultaneous OMP, and OMP based on first-order neighborhood system weighted classifiers, are utilized on the reconstructed HSI and the original HSI to verify the effectiveness of the proposed method. Specifically, using the reconstructed HSI, the average accuracy of the SVM classifier can be improved by as much as 19%.
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Free-living spirochetes from Cape Cod microbial mats detected by electron microscopy
Teal, T. H.; Chapman, M.; Guillemette, T.; Margulis, L.
1996-01-01
Spirochetes from microbial mats and anaerobic mud samples collected in salt marshes were studied by light microscopy, whole mount and thin section transmission electron microscopy. Enriched in cellobiose-rifampin medium, selective for Spirochaeta bajacaliforniensis, seven distinguishable spirochete morphotypes were observed. Their diameters ranged from 0.17 micron to > 0.45 micron. Six of these morphotypes came from southwest Cape Cod, Massachusetts: five from Microcoleus-dominated mat samples collected at Sippewissett salt marsh and one from anoxic mud collected at School Street salt marsh (on the east side of Eel Pond). The seventh morphotype was enriched from anoxic mud sampled from the north central Cape Cod, at the Sandy Neck salt marsh. Five of these morphotypes are similar or identical to previously described spirochetes (Leptospira, Spirochaeta halophila, Spirochaeta bajacaliforniensis, Spirosymplokos deltaeiberi and Treponema), whereas the other two have unique features that suggest they have not been previously described. One of the morphotypes resembles Spirosymplokos deltaeiberi (the largest free-living spirochete described), in its large variable diameter (0.4-3.0 microns), cytoplasmic granules, and spherical (round) bodies with composite structure. This resemblance permits its tentative identification as a Sippewissett strain of Spirosymplokos deltaeiberi. Microbial mats samples collected in sterile Petri dishes and stored dry for more than four years yielded many organisms upon rewetting, including small unidentified spirochetes in at least 4 out of 100 enrichments.
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Rodriguez Colon, B. J.; Rivera-Lopez, E. O.; Ramirez-Martinez, W. R.; Rios-Velazquez, C.; Perez-Valentin, K. A.
2017-12-01
Microbial mats are organosedimentary structures which house complex guilds of microbial communities, held together by a gelatinous exopolymeric substance (EPS). This biofilm contributes to the formation of laminations by binding and trapping sediments, as well as in-situ organomineralization. Microbial mats commonly thrive in extreme habitats, such as the hypersaline environments, which have been studied throughout several coastal regions in the Caribbean. This project aims to study the morphology, sedimentology, and mineralogy of five different modern hypersaline microbial mats from Puerto Rico and Anegada that have not yet been studied, to assess their differences/similarities. At the same time, we intent to isolate and characterize purple non-sulfur bacteria (PNSB), which is an anoxyphototrophic microorganism that contributes to the pink pigmentation observed in the second layer of a typical microbial mat. Different layers within each mat were separated, dissected and dissolved to remove all organic material. The resulting sediment was then analyzed mineralogically using X-ray diffraction, and used to make petrographic thin sections. To isolate PNSB candidates, serial dilutions followed by filtration were performed to extracted sections from the pink layer of each mat. The samples were planted in Petri dishes with marine media and placed in Anaerobic Jars. Colonies Descriptions, Gram stain and molecular analysis using 16S rDNA gene was performed. Preliminary results show a diversity of mat morphologies throughout the ponds, similar to what has been observed in other hypersaline ponds and marshes in the Caribbean. Sedimentary analysis shows that the mats from Puerto Rico have similar allochthonous material (e.g. Halimeda sp. fragments). Microcodium fabrics, conoform structures, and hemispheroidal morphologies were observed as well. In Anegada, lithified microbialites were observed in the Red Pond location. Mineralogically, all samples were similar except for the
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Full Text Available ... Donate Today Enroll in 123 What is Hepatic Encephalopathy? Hepatic Encephalopathy, sometimes referred to as portosystemic encephalopathy or PSE, is a condition that causes temporary ...
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ENDOTHELIUM LESION MARKERS AND THROMBOCYTE AGGREGATION IN CHRONIC HEPATITIS AND HEPATIC CIRRHOSIS
Directory of Open Access Journals (Sweden)
A. P. Shchekotova
2012-01-01
Full Text Available Aim — to estimate endothelium lesion, quantity and thrombocyte aggregation function correlation in viral chronic hepatitis C (CHC and hepatic cirrhosis (HC.Materials and methods. 50 CHC patients and 28 HC patients were examined. Using IFA method the total nitric oxide, endothelin‑1, vasculoendothelial growth factor levels, Willebrand factor (vWF activity were investigated, blood plasma desquamated endotheliocyte (DEC number was calculated with Hladovec method, 1978, thrombocyte aggregation (TA with ADP, collagen, ristocetine was determined.Results. DEC and vWF demonstrated correlation in CHC (p = 0.014 and HC (p = 0.000004. In HC patients reliable correlation of all the investigated indices of endothelium lesion with the thrombocyte number and TA was detected, but in CHC patients no correlations were revealed. Thus, significant elevation of TA with ristocetine was noted only in CHC. Decrease in thrombocyte amount among CHC patients and,especially in HC, and heightened vWF activity could change true TA indices. The corrected TA, whose indices in hepatic diseases significantlyincreased, was calculated taking into account the correction factor vWF / thrombocytes that in CHC did not differ from that of healthy patients and in HC was essentially higher.Conclusion. Endothelium dysfunction markers in CH and HC demonstrate correlation with thrombocyte reduction and TA elevation. Determinationof corrected TA permits to reveal disturbances of thrombocyte hemostasis in the form of elevated aggregation in all CHC and HC patients.
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Lemon, Stanley M; Walker, Christopher M
2018-05-07
Over the past two decades, progress in understanding human infections with hepatitis A virus (HAV) and hepatitis E virus (HEV) has been eclipsed by the priority of combating persistent hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. During that time, the global burden of liver disease caused by enteric hepatitis viruses has not abated. Because of vaccines, hepatitis A has become increasingly a disease of adults instead of early childhood in many regions of the world, resulting in an age-related shift toward more severe disease. HEV has remained endemic in many developing countries, and in well-developed, economically advanced countries it is now recognized as a cause of chronic, progressive liver disease in individuals with compromised immunity. The goal of this collection of articles is to review recent progress and to shine a bright light on gaps in our understanding of how these viruses replicate, cause disease, interact with the liver and host immune system, and are transmitted, along with prospects for improved control in human populations. Renewed efforts to study and compare HAV and HEV biology in humans and animal models have high potential to enhance our understanding of host-pathogen balance in the liver, and may contribute ultimately to the control of other infectious diseases of the liver. Copyright © 2018 Cold Spring Harbor Laboratory Press; all rights reserved.
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Energy Technology Data Exchange (ETDEWEB)
Saatci, I. [Dept. of Radiology, Hacettepe Univ. Hospital, Ankara (Turkey); Cila, A. [Dept. of Radiology, Hacettepe Univ. Hospital, Ankara (Turkey); Dincer, F.F. [Dept. of Radiology, Hacettepe Univ. Hospital, Ankara (Turkey)
1995-12-31
Cranial MRI findings in four patients who had hepatic dysfunction, including one with sole hepatic form of Wilson`s disease, were reported. The MR examinations revealed bilateral, symmetric hyperintensity in the globus pallidus, subthalamic nuclei and mesencephalon on T1-weighted images with no corresponding abnormality on T2-weighted sequences. The basal ganglia were normal on CT examinations in all patients. None of the patients had the clinical findings of hepatic encephalopathy. The MR findings in our patients did not correlate with the degree or duration of hepatic dysfunction. (orig.)
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Northup, D E; Melim, L A; Spilde, M N; Hathaway, J J M; Garcia, M G; Moya, M; Stone, F D; Boston, P J; Dapkevicius, M L N E; Riquelme, C
2011-09-01
Lava caves contain a wealth of yellow, white, pink, tan, and gold-colored microbial mats; but in addition to these clearly biological mats, there are many secondary mineral deposits that are nonbiological in appearance. Secondary mineral deposits examined include an amorphous copper-silicate deposit (Hawai'i) that is blue-green in color and contains reticulated and fuzzy filament morphologies. In the Azores, lava tubes contain iron-oxide formations, a soft ooze-like coating, and pink hexagons on basaltic glass, while gold-colored deposits are found in lava caves in New Mexico and Hawai'i. A combination of scanning electron microscopy (SEM) and molecular techniques was used to analyze these communities. Molecular analyses of the microbial mats and secondary mineral deposits revealed a community that contains 14 phyla of bacteria across three locations: the Azores, New Mexico, and Hawai'i. Similarities exist between bacterial phyla found in microbial mats and secondary minerals, but marked differences also occur, such as the lack of Actinobacteria in two-thirds of the secondary mineral deposits. The discovery that such deposits contain abundant life can help guide our detection of life on extraterrestrial bodies.
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Accessory hepatic vein: MR imaging
International Nuclear Information System (INIS)
Lee, Chang Hee; Rho, Tack Soo; Cha, Sang Hoon; Park, Cheol Min; Cha, In Ho
1995-01-01
To evaluate the MR appearance of the accessory hepatic veins. The study included 87 consecutive patients for whom abdominal MR images were obtained. The subjects who had liver lesion or hepatic vascular abnormalities were excluded. Couinaud classified accessory hepatic veins into inferior and middle right hepatic veins. Our major interests were evaluation of the incidence, morphology, and location of the accessory hepatic vein. Inferior right hepatic vein was demonstrated in 43 out of 87 patients (49%). The morphology was linear in 35 patients (80.5%), and V-shaped in 8 patients (19.5%). In 40 patients (93%), the inferior right hepatic vein was located in the posteroinferior aspect of the right lobe. Middle right hepatic vein was demonstrated in 7 out of 87 patients (8%). All were single linear in morphology, combined with the inferior right hepatic vein, and located between the right hepatic vein and inferior right hepatic vein. The accessory hepatic vein was demonstrated in 49% among the Korean adult population, and was located in posteroinferior portion of the liver, in 93%
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Features of Hepatitis in Hepatitis-associated Aplastic Anemia: Clinical and Histopathologic Study.
Patel, Kalyani R; Bertuch, Alison; Sasa, Ghadir S; Himes, Ryan W; Wu, Hao
2017-01-01
Hepatitis-associated aplastic anemia (HAA) is a rare variant of aplastic anemia in which patients present with severe pancytopenia after an episode of acute hepatitis. The marrow failure is often rapid, severe, and usually fatal if untreated. The preceding hepatitis is largely under-studied. Retrospective study of the clinical and histopathologic features of hepatitis in pediatric patients who subsequently developed aplastic anemia and comparison with consecutive cases of acute liver failure and random cases of autoimmune hepatitis during the same time frame. All 7 patients of HAA had significant elevations in aminotransferases and conjugated hyperbilirubinemia at initial presentation. Echoing liver function indices, cholestatic hepatitis with sinusoidal obstruction-type endothelial injury was seen histomorphologically. Autoimmune hepatitis serology such as anti-F-actin, anti-liver/kidney microsome, and hypergammaglobulinemia was negative in all patients. Five of 7 patients (71.4%) had, however, elevated antinuclear antibody, all with a speckled pattern. Hepatitis virus serology was negative in all patients. By immunohistochemical staining, the lobular CD8/CD4 lymphocyte ratio was markedly elevated in all of the initial samples with significant reduction in this ratio (P = 0.03) in 3 patients post treatment (ursodiol, antibiotics, and/or immunosuppressive therapy). Hepatitis preceding HAA is characterized by marked elevation of aminotransferases, conjugated hyperbilirubinemia, elevated antinuclear antibody with a speckled pattern, cholestatic hepatitis with sinusoidal obstruction morphology, and CD8 dominant lobular infiltrates. The present study suggests HAA may result from cytotoxic T-cell-mediated sinusoidal endothelial and hepatocytic injury.
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International Nuclear Information System (INIS)
Faiq, S.M.; Jesrani, A.; Jamal, M.; Lalwani, A.
2017-01-01
Objective: The purpose of this research is to evaluate common and uncommon variant of hepatic arterial anatomy that usually come across during Hepatic Angiographies. Study Design: Cross sectional study. Methods: This study included 50 patients having history of Hepatocellular Carcinoma from May to October 2015. Hepatic Angiography (Transarterial chemoembolization for management of Hepatoma and identification of classical and variant anatomy of hepatic artery) was evaluated in angiography unit. All procedures were performed on Digital Subtraction Angiography (DSA) machine (Toshiba KXO100 G). Selective DSA of the superior mesenteric artery and celiac trunk is performed initially to evaluate the frequency of normal and variant arterial anatomy and secondly to determine origin and course of tumor-feeding vessels. Evaluation of common and uncommon variants of hepatic arteries was done by using Michel’s classification as reference standard. Results: Age of the patient range from 40 – 80 years, 35 of whom were males. Fifty patients underwent angiographic procedure of viscera. Normal anatomy of hepatic artery was found in twenty eight (56%) cases. In six (12%) cases we found the replaced form of right hepatic artery (RHA) originating from visceral superior mesenteric artery. In five (10%) cases we found the replaced form of left hepatic artery (LHA) originating from left gastric artery (LGA), the combination of both these anomalies in one (2%) patient. Four (8%) cases had the left gastric artery giving rise to accessory left hepatic artery in conjunction with the common hepatic artery of celiac axis giving rise to typical right or left hepatic artery. In another four (8%) cases anatomic variation was noted in form of a dual arterial supply noted as common hepatic artery of celiac axis giving rise to typical left or right hepatic artery in conjunction with superior mesenteric artery giving rise to accessory right hepatic artery. In two (4%) cases superior mesenteric
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Potter, Elyn G; Bebout, Brad M; Kelley, Cheryl A
2009-05-01
The importance of hypersaline environments over geological time, the discovery of similar habitats on Mars, and the importance of methane as a biosignature gas combine to compel an understanding of the factors important in controlling methane released from hypersaline microbial mat environments. To further this understanding, changes in stable carbon isotopes of methane and possible methanogenic substrates in microbial mat communities were investigated as a function of salinity here on Earth. Microbial mats were sampled from four different field sites located within salterns in Baja California Sur, Mexico. Salinities ranged from 50 to 106 parts per thousand (ppt). Pore water and microbial mat samples were analyzed for the carbon isotopic composition of dissolved methane, dissolved inorganic carbon (DIC), and mat material (particulate organic carbon or POC). The POC delta(13)C values ranged from -6.7 to -13.5 per thousand, and DIC delta(13)C values ranged from -1.4 to -9.6 per thousand. These values were similar to previously reported values. The delta(13)C values of methane ranged from -49.6 to -74.1 per thousand; the methane most enriched in (13)C was obtained from the highest salinity area. The apparent fractionation factors between methane and DIC, and between methane and POC, within the mats were also determined and were found to change with salinity. The apparent fractionation factors ranged from 1.042 to 1.077 when calculated using DIC and from 1.038 to 1.068 when calculated using POC. The highest-salinity area showed the least fractionation, the moderate-salinity area showed the highest fractionation, and the lower-salinity sites showed fractionations that were intermediate. These differences in fractionation are most likely due to changes in the dominant methanogenic pathways and substrates used at the different sites because of salinity differences.
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Guo, Jun
Geosynthetics have been used to improve the performance of geomaterials, especially when weak soil exists in roadway applications. In this study, two types of geosynthetic materials, geocell and a mat system, were studied for their applications for unpaved roads and shoulders. The study of geocell was focused on its application for unpaved shoulders. The ability of geocell to improve different geomaterials over intermediate strength subgrade and its possible effect on vegetation were investigated. The study of the mat system was focused on investigating the performance of the mat system over soft and intermediate subgrade with different strengths under cyclic loading to simulate temporary roadway conditions. In the study of geocell for the application for unpaved shoulders, six large scale plate loading tests were conducted on a single type of geocell on target 5% CBR subgrade to investigate the benefits of geocell reinforcement on different base course and topsoil combinations. Different base course and topsoil combinations were investigated including: 200-mm thick unreinforced aggregate, 200-mm thick soil-aggregate mixture (50% aggregate and 50% top soil) with and without geocell reinforcement, 200-mm thick geocell-reinforced topsoil, 50-mm thick aggregate over 150-mm soil-aggregate mixture (50% aggregate and 50% top soil), and 50-mm thick top soil over 150-mm thick geocell-reinforced soil-aggregate mixture (50% aggregate and 50% top soil). Earth pressure cells were install at the interface between subgrade and base course to monitor the load distribution. The cyclic plate loading tests showed that geocell effectively reduced the permanent deformation and the geocell-reinforced soil-aggregate mixture slightly outperformed the unreinforced aggregate at the same thickness. The plate loading tests also suggested the topsoil cover resulted in large permanent deformations. A one-year long outdoor field vegetation test was conducted on base courses with different
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Directory of Open Access Journals (Sweden)
2007-05-01
Full Text Available A new treating method using sodium hydroxide (NaOH and Maleic anhydride-grafted polypropylene (MPP emulsion was introduced to treat jute fiber mat in order to enhance the performance of jute/polypropylene (PP composite prepared by film stacking method. The surface modifications of jute fiber mat have been found to be very effective in improving the fiber-matrix adhesion. It was shown that treatments changed not only the surface topography but also the distribution of diameter and strength for the jute fibers, which was analyzed by using a two-parameter Weibull distribution model. Consequently, the interfacial shear strength, flexural and tensile strength of the composites all increased, but the impact strength decreased slightly. These results have demonstrated a new approach to use natural materials to enhance the mechanical performances of composites.
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Han, Y-N
2009-01-01
This study aimed to identify acute self-limited hepatitis B (ASL-HB) among patients presenting with hepatitis B virus (HBV)-related acute hepatitis. Data were available for 220 patients diagnosed with HBV-related acute hepatitis, of whom 164 had acute hepatitis B (AHB). Of these, 160 were confirmed as ASL-HB: three (1.9%) evolved to chronic hepatitis B and one (0.6%) developed fulminant hepatitis and died. Comparisons were also made between AHB and acute infections with hepatitis A (HA) and hepatitis E (HE) viruses. During the study period, the number of patients with AHB exceeded the sum of those with acute HA and acute HE infections. There was no distinct seasonal peak for AHB infection, whereas both acute HA and acute HE infections occurred more frequently in the spring. Clinical symptoms and physical signs were similar for all three types of hepatitis, but significant differences were seen in some biochemical parameters. In conclusion, this study suggests that symptomatic AHB is not rare in China but it seldom evolves to chronic hepatitis B.
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Evaluation of tularemia cases focusing on the oculoglandular form.
Eren Gok, Sebnem; Kocagul Celikbas, Aysel; Baykam, Nurcan; Atay Buyukdemirci, Ayse; Eroglu, Mustafa Necati; Evren Kemer, Ozlem; Dokuzoguz, Basak
2014-10-15
Tularemia is a zoonotic disease caused by Francisella tularensis. The oculoglandular form is one of the rarest forms. In this study, evaluated tularemia patients, focusing on the ocular form and the efficacy of early antibiotic therapy. During a tularemia outbreak, the epidemiological and clinical findings, laboratory assays, and drugs used for the treatment of 48 patients were recorded prospectively. The diagnosis of tularemia was confirmed with microagglutination test (MAT) as well as clinical findings. The mean age of the subject was 48.6 years; 23 (47.9%) of them were female. Thirty-six (81.25%) patients had clinical presentation compatible with oropharyngeal tularemia, seven (14.58%) with oculoglandular tularemia, and two (4.1%) with ulceroglandular tularemia. The most common symptoms were fever (91.6%) and sore throat (81.2%), and the most common findings were lymphadenopathy (91.6%) and tonsillopharyngitis (81.2%). In the oculoglandular form, fever, lymphadenopathy, periorbital edema, conjunctival injection, and chemosis were found. The most distinctive ophthalmic feature was follicular conjunctivitis and conjunctival epithelial defects. Forty-five cases had positive serological results with MAT. All the patients were treated with antibiotics considered effective against F. tularensis, and topical antimicrobial treatment was given to the patients with oculoglandular tularemia. Twenty-six (54.16%) patients, who were admitted within three weeks of the onset of symptoms, recovered without sequel. During tularemia outbreaks, ocular involvement should be considered carefully. The early administration of appropriate treatment will be more effective in resolving the infection and preventing complications. Along with systemic antibiotic therapy, topical treatment will help recovery.
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... common causes of viral hepatitis are hepatitis A virus (HAV), hepatitis B virus (HBV), and hepatitis C virus (HCV). HBV and HCV are common ... gov/ mmwr/ preview/ mmwrhtml/ rr5516a1. htm? s_ cid= rr5516a1_ e. The Numbers • • Of people with HIV in the ...
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Recurrent paratyphoid fever A co-infected with hepatitis A reactivated chronic hepatitis B.
Liu, Yanling; Xiong, Yujiao; Huang, Wenxiang; Jia, Bei
2014-05-12
We report here a case of recurrent paratyphoid fever A with hepatitis A co-infection in a patient with chronic hepatitis B. A 26-year-old male patient, who was a hepatitis B virus carrier, was co-infected with Salmonella enterica serovar Paratyphi A and hepatitis A virus. The recurrence of the paratyphoid fever may be ascribed to the coexistence of hepatitis B, a course of ceftriaxone plus levofloxacin that was too short and the insensitivity of paratyphoid fever A to levofloxacin. We find that an adequate course and dose of ceftriaxone is a better strategy for treating paratyphoid fever. Furthermore, the co-infection of paratyphoid fever with hepatitis A may stimulate cellular immunity and break immunotolerance. Thus, the administration of the anti-viral agent entecavir may greatly improve the prognosis of this patient with chronic hepatitis B, and the episodes of paratyphoid fever and hepatitis A infection prompt the use of timely antiviral therapy.
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Intestinal volvulus with coagulative hepatic necrosis in a chicken.
Haridy, Mohie; Goryo, Masanobu; Sasaki, Jun; Okada, Kosuke
2010-04-01
A 7-week-old SPF chicken inoculated at 4 weeks of age with chicken anemia virus was puffed up depressed and had ruffled feathers and a good body condition. Intestinal volvulus involving the jejunum and part of the duodenum forming two loops with one knob was observed. Microscopically, venous infarction of the obstructed loops, periportal and sublobular multifocal coagulative hepatic necrosis and granulomatous inflammation of the cecal tonsils were observed. Gram staining revealed no bacteria in hepatic tissue; however, gram-positive bacilli were detected in the necrotic debris in the intestinal lumen. Immunosuppression might have predisposed the chicken to intestinal and cecal tonsil infection that then progressed to volvulus. Loss of the mucosal barrier in infarction might allow bacterial toxins and vasoactive factors to escape into the systemic circulation (toxemia) and be responsible for the hepatic necrosis.
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Directory of Open Access Journals (Sweden)
Kazim Sahin
2018-01-01
Full Text Available Mucuna pruriens, Ashwagandha, and Tribulus terrestris are known as the enhancers for sexual health, functional activities, vitality, and longevity. These herbs had been widely used in the Ayurveda medicine as aphrodisiacs through the ages, and their efficacy was also verified separately in our previous publication. Therefore, the aim of this study was to determine the effects of Mucuna, Ashwagandha, and Tribulus complexes on sexual function in rats. Twenty-eight male rats allocated to four groups as follows: (i negative control (C; (ii positive control or sildenafil citrate treated group (5 mg/kg (S; (iii MAT1 (combination of 10 mg Mucuna (M + 10 mg Ashwagandha (A + 10 mg Tribulus (T/kg BW; (iv MAT 2 (20 mg Mucuna + 20 mg Ashwagandha + 20 mg Tribulus/kg BW. There was no significant difference found between the MAT1 and MAT2 groups while they showed significantly increased testosterone, follicle-stimulating hormone (FSH, and luteinizing hormone (LH levels when compared to the negative control. Significant increases in Nrf2/HO1 levels and decreases in NF-κB were detected in MAT groups similar to the decrease in serum and testis malondialdehyde (MDA levels as compared to both controls. The sperm motility, count, and rate also significantly improved in both MAT groups, while ALT, AST, creatinine, ALP, and urea levels did not change in any of the groups. Oral consumption of MATs combination in male rats resulted in inhibition of NF-κB and MDA and also increased sex hormones with Nrf2-mediated HO-1 induction. MAT combinations may improve sexual functions by increasing levels of sexual hormones and regulation of NF-κB and Nrf2/HO-1 signaling pathways.