Science.gov

Sample records for alcohol tba biodegradation

  1. IS YOUR TBA COMING FROM BIODEGRADATION OF MTBE

    EPA Science Inventory

    MTBE (methyl tertiary butyl ether) is present at high concentrations in ground water at many sites where gasoline has been spilled from underground storage tanks. In addition, TBA (tertiary butyl alcohol) is also present at high concentrations in many of the same ground waters. ...

  2. TBA biodegradation in surface-water sediments under aerobic and anaerobic conditions

    USGS Publications Warehouse

    Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.

    2002-01-01

    The potential for [U-14C] TBA biodegradation was examined in laboratory microcosms under a range of terminal electron accepting conditions. TBA mineralization to CO2 was substantial in surface-water sediments under oxic, denitrifying, or Mn(IV)-reducing conditions and statistically significant but low under SO4-reducing conditions. Thus, anaerobic TBA biodegradation may be a significant natural attenuation mechanism for TBA in the environment, and stimulation of in situ TBA bioremediation by addition of suitable terminal electron acceptors may be feasible. No degradation of [U-14C] TBA was observed under methanogenic or Fe(III)-reducing conditions.

  3. TBA IN GROUND WATER FROM THE NATURAL BIODEGRADATION OF MTBE

    EPA Science Inventory

    At many UST spills, the concentrations of TBA in ground water are much higher than would be expected from the presence of TBA in the gasoline originally spilled. The ratio of concentrations of TBA to concentrations of MTBE in monitoring wells at gasoline spill sites was compared ...

  4. MICROCOSM STUDY OF ANAEROBIC BIODEGRADATION OF MTBE AND TBA

    EPA Science Inventory

    Ground water samples collected in at a gasoline spill sites in Orange County, California, suggested that MTBE was being transformed to TBA. In some of the most heavily contaminated wells, the concentration of TBA was higher than the concentration of MTBE (MTBE 2 µg/L and TBA 40,...

  5. Forensic analysis of tertiary-butyl alcohol (TBA) detections in a hydrocarbon-rich groundwater basin.

    PubMed

    Quast, Konrad W; Levine, Audrey D; Kester, Janet E; Fordham, Carolyn L

    2016-04-01

    Tertiary-butyl alcohol (TBA), a high-production volume (HPV) chemical, was sporadically detected in groundwater and coalbed methane (CBM) wells in southeastern Colorado's hydrocarbon-rich Raton Basin. TBA concentrations in shallow water wells averaged 75.1 μg/L, while detections in deeper CBM wells averaged 14.4 μg/L. The detection of TBA prompted a forensic investigation to try to identify potential sources. Historic and recent data were reviewed to determine if there was a discernable pattern of TBA occurrence. Supplemental samples from domestic water wells, monitor wells, CBM wells, surface waters, and hydraulic fracturing (HF) fluids were analyzed for TBA in conjunction with methyl tertiary-butyl ether (MTBE) and ethyl tertiary-butyl ether (ETBE), proxies for evidence of contamination from reformulated gasoline or associated oxygenates. Exploratory microbiological sampling was conducted to determine if methanotrophic organisms co-occurred with TBA in individual wells. Meaningful comparisons of historic TBA data were limited due to widely varying reporting limits. Mapping of TBA occurrence did not reveal any spatial patterns or physical associations with CBM operations or contamination plumes. Additionally, TBA was not detected in HF fluids or surface water samples. Given the widespread use of TBA in industrial and consumer products, including water well completion materials, it is likely that multiple diffuse sources exist. Exploratory data on stable isotopes, dissolved gases, and microbial profiling provide preliminary evidence that methanotrophic activity may be producing TBA from naturally occurring isobutane. Reported TBA concentrations were significantly below a conservative risk-based drinking water screening level of 8000 μg/L derived from animal toxicity data.

  6. Natural Anaerobic Biodegradation of TBA in Aquifer Sediments at Gasoline Spill Sites

    EPA Science Inventory

    TBA is an important contaminant at spills sites of gasoline that contains MTBE. The impact of TBA is particularly important in Southern California, where the State Action Level for TBA is 12 μg/L and many communities produce ground water for drinking water from an urban landscape...

  7. Role of back diffusion and biodegradation reactions in sustaining an MTBE/TBA plume in alluvial media

    USGS Publications Warehouse

    Rasa, Ehsan; Chapman, Steven W.; Bekins, Barbara A.; Fogg, Graham E.; Scow, Kate M.; Mackay, Douglas M.

    2011-01-01

    A methyl tert-butyl ether (MTBE) / tert-butyl alcohol (TBA) plume originating from a gasoline spill in late 1994 at Vandenberg Air Force Base (VAFB) persisted for over 15 years within 200 feet of the original spill source. The plume persisted until 2010 despite excavation of the tanks and piping within months after the spill and excavations of additional contaminated sediments from the source area in 2007 and 2008. The probable history of MTBE concentrations along the plume centerline at its source was estimated using a wide variety of available information, including published details about the original spill, excavations and monitoring by VAFB consultants, and our own research data. Two-dimensional reactive transport simulations of MTBE along the plume centerline were conducted for a 20-year period following the spill. These analyses suggest that MTBE diffused from the thin anaerobic aquifer into the adjacent anaerobic silts and transformed to TBA in both aquifer and silt layers. The model reproduces the observation that after 2004 TBA was the dominant solute, diffusing back out of the silts into the aquifer and sustaining plume concentrations much longer than would have been the case in the absence of such diffusive exchange. Simulations also suggest that aerobic degradation of MTBE or TBA at the water table in the overlying silt layer significantly affected concentrations of MTBE and TBA by limiting the chemical mass available for back diffusion to the aquifer.

  8. Role of back diffusion and biodegradation reactions in sustaining an MTBE/TBA plume in alluvial media

    PubMed Central

    Rasa, Ehsan; Chapman, Steven W.; Bekins, Barbara A.; Fogg, Graham E.; Scow, Kate M.; Mackay, Douglas M.

    2012-01-01

    A methyl tert-butyl ether (MTBE) / tert-butyl alcohol (TBA) plume originating from a gasoline spill in late 1994 at Vandenberg Air Force Base (VAFB) persisted for over 15 years within 200 feet of the original spill source. The plume persisted until 2010 despite excavation of the tanks and piping within months after the spill and excavations of additional contaminated sediments from the source area in 2007 and 2008. The probable history of MTBE concentrations along the plume centerline at its source was estimated using a wide variety of available information, including published details about the original spill, excavations and monitoring by VAFB consultants, and our own research data. Two-dimensional reactive transport simulations of MTBE along the plume centerline were conducted for a 20-year period following the spill. These analyses suggest that MTBE diffused from the thin anaerobic aquifer into the adjacent anaerobic silts and transformed to TBA in both aquifer and silt layers. The model reproduces the observation that after 2004 TBA was the dominant solute, diffusing back out of the silts into the aquifer and sustaining plume concentrations much longer than would have been the case in the absence of such diffusive exchange. Simulations also suggest that aerobic degradation of MTBE or TBA at the water table in the overlying silt layer significantly affected concentrations of MTBE and TBA by limiting the chemical mass available for back diffusion to the aquifer. PMID:22115089

  9. In Situ Biotreatment of TBA with Recirculation/Oxygenation

    PubMed Central

    North, Katharine P.; Mackay, Douglas M.; Kayne, Julian S.; Petersen, Daniel; Rasa, Ehsan; Rastegarzadeh, Laleh; Holland, Reef B.; Scow, Kate M.

    2012-01-01

    The potential for in situ biodegradation of tert-butyl alcohol (TBA) by creation of aerobic conditions in the subsurface with recirculating well pairs was investigated in two field studies conducted at Vandenberg Air Force Base (VAFB). In the first experiment, a single recirculating well pair with bromide tracer and oxygen amendment successfully delivered oxygen to the subsurface for 42 days. TBA concentrations were reduced from approximately 500 μg/L to below the detection limit within the treatment zone and the treated water was detected in a monitoring transect several meters downgradient. In the second experiment, a site-calibrated model was used to design a double recirculating well pair with oxygen amendment, which successfully delivered oxygen to the subsurface for 291 days and also decreased TBA concentrations to below the detection limit. Methylibium petroleiphilum strain PM1, a known TBA-degrading bacterium, was detectable at the study site but addition of oxygen had little impact on the already low baseline population densities, suggesting that there was not enough carbon within the groundwater plume to support significant new growth in the PM1 population. Given favorable hydrogeologic and geochemical conditions, the use of recirculating well pairs to introduce dissolved oxygen into the subsurface is a viable method to stimulate in situ biodegradation of TBA or other aerobically-degradable aquifer contaminants. PMID:23358537

  10. Misconceptions concerning the behavior, fate and transport of the fuel oxygenates TBA and MTBE

    NASA Astrophysics Data System (ADS)

    Woodward, R.; Sloan, R.

    2003-04-01

    The release of gasoline from underground storage tanks and the subsequent appearance of dissolved constituents in drinking water has focused attention on the use of MTBE in reformulated fuels. Natural biodegradation of MTBE in soil, photo-oxidation in the atmosphere or chemical oxidation during remediation of gasoline releases can produce the intermediate tertiary butyl alcohol (TBA). TBA is also a fuel oxygenate and can be found as a co-product in MTBE synthesized from methanol and TBA. Because the physical properties of ethers and alcohols differ somewhat from the predominant hydrocarbon compounds in gasoline, misconceptions have developed about the behavior of fuel oxygenates in storage and in the subsurface. Critical review of several misconceptions about MTBE and TBA in gasoline reveals the concepts were conceived to rationalize early field observations and/or incomplete data sets. Closer scrutiny, in light of recent laboratory investigations, field data, case studies and world literature, clarifies these misconceptions and assumptions about the behavior of ether oxygenates and their degradation products in the environment. Commonly held misconceptions focus on four general areas of fuel and fuel oxygenate management: storage/dispensing, hydrology, remediation, and health effects. Storage/dispensing misconceptions address materials stability to ethers and alcohols in fuel and the environmental forensics of fuel systems failure. Groundwater and hydrology misconceptions deal with plume dynamics and the impact of fuel on drinking water resources. Remediation misconceptions focus on the performance of traditional hydrocarbon remediation technologies, recent developments in biodegradation and natural attenuation, drivers of remedial design and remediation costs. Health effects misconceptions address both acute and chronic exposure risk evaluations by national and international health agencies. Generally MTBE and TBA are manageable by the same processes and

  11. MTBE, TBA, and TAME attenuation in diverse hyporheic zones

    USGS Publications Warehouse

    Landmeyer, J.E.; Bradley, P.M.; Trego, D.A.; Hale, K.G.; Haas, J.E.

    2010-01-01

    Groundwater contamination by fuel-related compounds such as the fuel oxygenates methyl tert-butyl ether (MTBE), tert-butyl alcohol (TBA), and tert-amyl methyl ether (TAME) presents a significant issue to managers and consumers of groundwater and surface water that receives groundwater discharge. Four sites were investigated on Long Island, New York, characterized by groundwater contaminated with gasoline and fuel oxygenates that ultimately discharge to fresh, brackish, or saline surface water. For each site, contaminated groundwater discharge zones were delineated using pore water geochemistry data from 15 feet (4.5 m) beneath the bottom of the surface water body in the hyporheic zone and seepage-meter tests were conducted to measure discharge rates. These data when combined indicate that MTBE, TBA, and TAME concentrations in groundwater discharge in a 5-foot (1.5-m) thick section of the hyporheic zone were attenuated between 34% and 95%, in contrast to immeasurable attenuation in the shallow aquifer during contaminant transport between 0.1 and 1.5 miles (0.1 to 2.4 km). The attenuation observed in the hyporheic zone occurred primarily by physical processes such as mixing of groundwater and surface water. Biodegradation also occurred as confirmed in laboratory microcosms by the mineralization of U- 14C-MTBE and U- 14C-TBA to 14CO2 and the novel biodegradation of U- 14C-TAME to 14CO2 under oxic and anoxic conditions. The implication of fuel oxygenate attenuation observed in diverse hyporheic zones suggests an assessment of the hyporheic zone attenuation potential (HZAP) merits inclusion as part of site assessment strategies associated with monitored or engineered attenuation. ?? 2009 National Ground Water Association.

  12. Using DNA-Stable Isotope Probing to Identify MTBE- and TBA-Degrading Microorganisms in Contaminated Groundwater

    PubMed Central

    Key, Katherine C.; Sublette, Kerry L.; Duncan, Kathleen; Mackay, Douglas M.; Scow, Kate M.; Ogles, Dora

    2014-01-01

    Although the anaerobic biodegradation of methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) has been documented in the laboratory and the field, knowledge of the microorganisms and mechanisms involved is still lacking. In this study, DNA-stable isotope probing (SIP) was used to identify microorganisms involved in anaerobic fuel oxygenate biodegradation in a sulfate-reducing MTBE and TBA plume. Microorganisms were collected in the field using Bio-Sep® beads amended with 13C5-MTBE, 13C1-MTBE (only methoxy carbon labeled), or13C4-TBA. 13C-DNA and 12C-DNA extracted from the Bio-Sep beads were cloned and 16S rRNA gene sequences were used to identify the indigenous microorganisms involved in degrading the methoxy group of MTBE and the tert-butyl group of MTBE and TBA. Results indicated that microorganisms were actively degrading 13C-labeled MTBE and TBA in situ and the 13C was incorporated into their DNA. Several sequences related to known MTBE- and TBA-degraders in the Burkholderiales and the Sphingomonadales orders were detected in all three13C clone libraries and were likely to be primary degraders at the site. Sequences related to sulfate-reducing bacteria and iron-reducers, such as Geobacter and Geothrix, were only detected in the clone libraries where MTBE and TBA were fully labeled with 13C, suggesting that they were involved in processing carbon from the tert-butyl group. Sequences similar to the Pseudomonas genus predominated in the clone library where only the methoxy carbon of MTBE was labeled with 13C. It is likely that members of this genus were secondary degraders cross-feeding on 13C-labeled metabolites such as acetate. PMID:25525320

  13. In Situ Biodegradation of MTBE and TBA

    EPA Science Inventory

    Ground water at most UST spills sites in Kansas contains both MTBE and benzene, and both contaminants must be effectively treated to close the sites. Soil vacuum extraction, and air sparging are common treatment technologies in Kansas. The technologies supply oxygen to support ...

  14. STABLE ISOTOPE ANALYSIS OF MTBE TO EVALUATE THE SOURCE OF TBA IN GROUND WATER

    EPA Science Inventory

    Although tert-butyl alcohol (TBA) has not been used as a fuel oxygenate in Orange County, California, the concentrations of TBA in ground water at gasoline spill sites are high compared those of the conventional fuel oxygenate methyl tert-butyl ether (MTBE). In the year 2002, th...

  15. HYDROLYSIS OF MTBE TO TBA IN GROUND WATER SAMPLES WITH HYDROCHLORIC ACID

    EPA Science Inventory

    Conventional sampling and analytical protocols have poor sensitivity for fuel oxygenates that are alcohols, such as tert-butyl alcohol (TBA). Because alcohols are miscible or highly soluble in water, alcohols are not efficiently transferred to the gas chromatograph for analysis....

  16. IDENTIFYING THE CAUSE OF HIGH CONCENTRATIONS OF TBA IN GROUNDWATER AT GASOLINE SPIILL SITES IN ORANGE COUNTY, CALIFORNIA

    EPA Science Inventory

    Monitoring at gasoline spills in Orange County, California has revealed that TBA (tertiary butyl alcohol) is often present at high concentrations in ground water. To manage the hazard associated with the presence of TBA, staff of the UST Local Oversight Program (LOP) of the Oran...

  17. ANAEROBIC DEGRADATION OF MTBE TO TBA IN GROUND WATER AT GASOLINE SPILL SITES IN ORANGE COUNTY, CALIFORNIA

    EPA Science Inventory

    Although tert-Butyl Alcohol (TBA) has not been used as a fuel oxygenate in Orange County, California, the concentrations of TBA in ground water at gasoline spill sites are high compared to the concentrations of the conventional fuel oxygenate Methyl tert-Butyl Ether (MTBE). In t...

  18. COMPOUND-SPECIFIC ISOTOPE ANALYSIS OF MTBE AND TBA FOR BIOREMEDIATION STUDIES

    EPA Science Inventory

    The utility of stable isotope ratios to detect biodegradation for a number of chemical compounds including MTBE and TBA has been demonstrated in a number of laboratory or field studies. Chemical reactions tend to favor molecules with the lighter isotopic species (e.g., 12C, 1H), ...

  19. TBA PRODUCTION BY ACID HYDROLYSIS OF MTBE DURING HEATED HEADSPACE ANALYSIS & EVALUATION OF A BASE AS A PRESERVATIVE

    EPA Science Inventory

    At room temperature (20°±3°C), purge and trap samplers provide poor sensitivity for analysis of the fuel oxygenates that are alcohols, such as tertiary butyl alcohol (TBA). Because alcohols are miscible or highly soluble in water, they are not efficiently transferred to a gas chr...

  20. Microbial degradation of methyl tert-butyl ether and tert-butyl alcohol in the subsurface

    NASA Astrophysics Data System (ADS)

    Schmidt, Torsten C.; Schirmer, Mario; Weiß, Holger; Haderlein, Stefan B.

    2004-06-01

    The fate of fuel oxygenates such as methyl tert-butyl ether (MTBE) in the subsurface is governed by their degradability under various redox conditions. The key intermediate in degradation of MTBE and ethyl tert-butyl ether (ETBE) is tert-butyl alcohol (TBA) which was often found as accumulating intermediate or dead-end product in lab studies using microcosms or isolated cell suspensions. This review discusses in detail the thermodynamics of the degradation processes utilizing various terminal electron acceptors, and the aerobic degradation pathways of MTBE and TBA. It summarizes the present knowledge on MTBE and TBA degradation gained from either microcosm or pure culture studies and emphasizes the potential of compound-specific isotope analysis (CSIA) for identification and quantification of degradation processes of slowly biodegradable pollutants such as MTBE and TBA. Microcosm studies demonstrated that MTBE and TBA may be biodegradable under oxic and nearly all anoxic conditions, although results of various studies are often contradictory, which suggests that site-specific conditions are important parameters. So far, TBA degradation has not been shown under methanogenic conditions and it is currently widely accepted that TBA is a recalcitrant dead-end product of MTBE under these conditions. Reliable in situ degradation rates for MTBE and TBA under various geochemical conditions are not yet available. Furthermore, degradation pathways under anoxic conditions have not yet been elucidated. All pure cultures capable of MTBE or TBA degradation isolated so far use oxygen as terminal electron acceptor. In general, compared with hydrocarbons present in gasoline, fuel oxygenates biodegrade much slower, if at all. The presence of MTBE and related compounds in groundwater therefore frequently limits the use of in situ biodegradation as remediation option at gasoline-contaminated sites. Though degradation of MTBE and TBA in field studies has been reported under oxic

  1. Lignin biodegradation and the production of ethyl alcohol from cellulose

    SciTech Connect

    Rosenberg, S.L.; Wilke, C.R.

    1981-02-01

    During the last few years our group has been engaged in developing a biochemical process for the conversion of lignocellulosic materials to ethyl alcohol. Lignin is a barrier to complete cellulose saccharification in this process, but chemical and physical delignification steps are too expensive to be used at the present time. An enzymatic delignification process might be attractive for several reasons: little energy would be expected to be needed, enzymes could be recovered and reused, and useful chemicals might be produced from dissolved lignin. A number of thermophilic and thermotolerant fungi were examined for the ability to rapidly degrade lignocellulose in order to find an organism whcih produced an active lignin-degrading enzyme system. Chryosporium pruinosum and Sporotrichum pulverulentum were found to be active lignocellulose degraders, and C. pruinosum was chosen for further study. Lignin and carbohydrate were degraded when the substrate remained moistened by, but not submerged in, the liquid medium. Attempts were made to demonstrate a cell-free lignin degrading system by both extraction and pressing of cultures grown on moist lignocellulose. Carbohydrate-degrading activity was found but not lignin-degrading activity. This led us to ask whether diffusible lignin-degrading activity could be demonstrated in this organism. The data indicate that the lignin degradation system, or one or more of its components, produced by this organism is either unstable, non-diffusible, or inactive at small distances (about 1 mm) from growing hyphae. At present, studies are being conducted using diffusion cultures to select mutants of C. pruinosum that do produce a diffusible lignin degradation system. We are also examining a number of mesophilic lignin-degrading molds for this ability.

  2. EFFECT OF BTEX ON THE DEGRADATION OF MTBE AND TBA BY MIXED BACTERIAL CONSORTIUM

    EPA Science Inventory

    Methyl tert-butyl ether (MTBE) contamination in groundwater often coexists with benzene, toluene, ethylbenzene, and xylene (BTEX) near the source of the plume. Tertiary butyl alcohol (TBA) is a prevalent intermediate of MTBE degradation. Therefore, there is a significant p...

  3. Metabolites and biodegradation pathways of fatty alcohol ethoxylates in microbial biocenoses of sewage treatment plants.

    PubMed Central

    Steber, J; Wierich, P

    1985-01-01

    The biodegradation of fatty alcohol polyglycol ethers was studied by analyzing the 14C-labeled intermediates isolated from the effluent of a model continuous-flow sewage treatment plant after dosage of either alkyl- or heptaglycol-labeled stearyl alcohol ethoxylate (SA-7EO). In each case, uncharged and carboxylated (mainly dicarboxylated) polyethylene glycols constituted the most prominent metabolites. The results indicate that there is a faster degradation of the alkyl than the polyethylene glycol moiety and that there are two distinct primary degradation mechanisms acting simultaneously in microbial biocenoses: intramolecular scission of the surfactant as well as omega- and beta-oxidation of the alkyl chain. Characterization of the bulk of 14C-labeled metabolites as a homologous series of neutral and acidic polyglycol units and identification of several C2-fragments accounted for the depolymerization of the hydrophilic part of the surfactant by stepwise cleavage of ether-bound EO units; from additional degradation studies employing either neutral or carboxylated 14C-labeled polyethylene glycols as model metabolites, it was concluded that hydrolytic as well as oxidative cleavage of C2-units is involved. Most of the identified low-molecular-weight 14C-labeled acids suggest an ultimate degradation of EO monomers by the oxidative dicarbonic acid cycle or the glycerate pathway or both. In addition, the finding of considerable amounts of oxalic and formic acids allow consideration of an additional mineralization route via glyoxylic, oxalic, and formic acids. The simultaneous action of different degradation mechanisms indicates the involvement of several distinct bacterial groups in the biodegradation of fatty alcohol ethoxylates under environmental conditions. PMID:3994363

  4. AEROBIC BIODEGRADATION OF GASOLINE OXYGENATES MTBE AND TBA

    EPA Science Inventory

    MTBE degradation was investigated using a continuously stirred tank reactor (CSTR) with biomass retention (porous pot reactor) operated under aerobic conditions. MTBE was fed to the reactor at an influent concentration of 150 mg/l (1.70 mmol/l). A second identifical rector was op...

  5. Anaerobic digestion of starch-polyvinyl alcohol biopolymer packaging: biodegradability and environmental impact assessment.

    PubMed

    Guo, M; Trzcinski, A P; Stuckey, D C; Murphy, R J

    2011-12-01

    The digestibility of a starch-polyvinyl alcohol (PVOH) biopolymer insulated cardboard coolbox was investigated under a defined anaerobic digestion (AD) system with key parameters characterized. Laboratory results were combined with industrial operational data to develop a site-specific life cycle assessment (LCA) model. Inoculated with active bacterial trophic groups, the anaerobic biodegradability of three starch-PVOH biopolymers achieved 58-62%. The LCA modeling showed that the environmental burdens of the starch-PVOH biopolymer packaging under AD conditions on acidification, eutrophication, global warming and photochemical oxidation potential were dominated by atmospheric emissions released from substrate degradation and fuel combustion, whereas energy consumption and infrastructure requirements were the causes of abiotic depletion, ozone depletion and toxic impacts. Nevertheless, for this bio-packaging, AD of the starch-PVOH biopolymer combined with recycling of the cardboard emerged as the environmentally superior option and optimization of the energy utilization system could bring further environmental benefits to the AD process.

  6. Structural analysis, and antioxidant and antibacterial properties of chitosan-poly (vinyl alcohol) biodegradable films.

    PubMed

    Hajji, Sawssen; Chaker, Achraf; Jridi, Mourad; Maalej, Hana; Jellouli, Kemel; Boufi, Sami; Nasri, Moncef

    2016-08-01

    The development and characterization of biodegradable blend films based on chitosan and poly (vinyl alcohol) for possible use in a variety of biological activities are reported. Fourier transform infrared spectroscopy (FTIR) spectra of chitosan-poly (vinyl alcohol) (Ch/PVA) films showed characteristics peaks shifting to a lower frequency range due to hydrogen bonding between -OH of PVA and -NH2 of chitosan. The chitosan and PVA polymers presented good compatibility. The morphology study of chitosan and composite films showed a compact and homogenous structure. The tensile strength and elongation at break increased with PVA content. In fact, the highest tensile strength and elongation at break (53.58 MPa and 454 %) occurs with pure PVA film. The results showed that PVA incorporation in the blends contributes to increase the intermolecular interactions, thus improving the mechanical properties. In addition, the prepared films demonstrated high antioxidant activities monitored by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging, reducing power, and β-carotene bleaching activity. Nevertheless, PVA addition reduced antioxidant and antibacterial activities against Gram-positive and Gram-negative bacteria tested.

  7. Anaerobic biodegradability of alkylphenols and fuel oxygenates in the presence of alternative electron acceptors.

    PubMed

    Puig-Grajales, L; Tan, N G; van der Zee, F; Razo-Flores, E; Field, J A

    2000-11-01

    Alkylphenols and fuel oxygenates are important environmental pollutants produced by the petrochemical industry. A batch biodegradability test was conducted with selected ortho-substituted alkylphenols (2-cresol, 2,6-dimethylphenol and 2-ethylphenol), fuel oxygenates (methyl tert-butyl ether, ethyl tert-butyl ether and tert-amylmethyl ether) and tert-butyl alcohol (TBA) as model compounds. The ortho-substituted alkylphenols were not biodegraded after 100 days of incubation under methanogenic, sulfate-, or nitrate-reducing conditions. However, biodegradation of 2-cresol and 2-ethylphenol (150 mg l(-1)) was observed in the presence of Mn (IV) as electron acceptor. The biodegradation of these two compounds took place in less than 15 days and more than 90% removal was observed for both compounds. Mineralization was indicated since no UV-absorbing metabolites accumulated after 23 days of incubation. These alkylphenols were also slowly chemically oxidized by Mn (IV). No biodegradation of fuel oxygenates or TBA (1 g l(-1)) was observed after 80 or more days of incubation under methanogenic, Fe (III)-, or Mn (IV)-reducing conditions, suggesting that these compounds are recalcitrant under anaerobic conditions. The fuel oxygenates caused no toxicity towards acetoclastic methanogens activity in anaerobic granular sludge.

  8. An ex situ evaluation of TBA- and MTBE-baited bio-traps

    PubMed Central

    North, Katharine P.; Mackay, Douglas M.; Annable, Michael D.; Sublette, Kerry L.; Davis, Greg; Holland, Reef B.; Petersen, Daniel; Scow, Kate M.

    2013-01-01

    Aquifer microbial communities can be investigated using Bio-traps® (“bio-traps”), passive samplers containing Bio-Sep® beads (“bio-beads”) that are deployed in monitoring wells to be colonized by bacteria delivered via groundwater flow through the well. When bio-beads are “baited” with organic contaminants enriched in 13C, stable isotope probing allows assessment of the composition and activity of the microbial community. This study used an ex situ system fed by groundwater continuously extracted from an adjacent monitoring well within an experimentally-created aerobic zone treating a tert-butyl alcohol (TBA) plume. The goal was to evaluate aspects of bio-trap performance that cannot be studied quantitatively in situ. The measured groundwater flow through a bio-trap housing suggests that such traps might typically “sample” about 1.8 L per month. The desorption of TBA or methyl tert-butyl ether (MTBE) bait from bio-traps during a typical deployment duration of 6 weeks was approximately 90% and 45%, respectively, of the total initial bait load, with initially high rate of mass loss that decreased markedly after a few days. The concentration of TBA in groundwater flowing by the TBA-baited bio-beads was estimated to be as high as 3400 mg/L during the first few days, which would be expected to inhibit growth of TBA-degrading microbes. Initial inhibition was also implied for the MTBE-baited bio-trap, but at lower concentrations and for a shorter time. After a few days, concentrations in groundwater flowing through the bio-traps dropped below inhibitory concentrations but remained 4–5 orders of magnitude higher than TBA or MTBE concentrations within the aquifer at the experimental site. Desorption from the bio-beads during ex situ deployment occurred at first as predicted by prior sorption analyses of bio-beads but with apparent hysteresis thereafter, possibly due to mass transfer limitations caused by colonizing microbes. These results suggest that

  9. Biodegradation of high concentration of nitrobenzene by Pseudomonas corrugata embedded in peat-phosphate esterified polyvinyl alcohol.

    PubMed

    Liu, Na; Li, Hai-Jun; Shi, Yue-E; Zhu, Bo-Lin; Gao, Song

    2013-10-01

    Efficiency on biodegradation of high concentration of nitrobenzene (NB) by peat-phosphate esterified polyvinyl alcohol-embedded NB-degrading bacteria Pseudomonas corrugata was conducted compared to free bacteria cells. Its biodegradation kinetics, reuse ability, degradation effect in the absence of the essential element needed for the growth of bacteria and degradation efficiency of the raw water from the contaminated site were also invested. Results show that the degradation rate when the concentration of NB was at 600, 750, and 900 mg/L reached 91.02, 83.23, and 55.9 %, which was higher than that observed in free bacteria at the same concentration levels. Biodegradation kinetics of the material could be well described by first- and zero-order kinetics when the concentration of NB was at 300, 450 mg/L and 600, 750, 900 mg/L, respectively. Stable degradation activity (stayed at a level of approximately 70 %) was displayed during the 11th repeat-batch experiment. The affect of absence of phosphorus in the medium can be abated ascribed to the addition of peat, which contributes with organic matter and other elements such as nitrogen and phosphorus necessary to maintain metabolically active the microorganisms. Effective biodegradation of the raw water from the experimental site revealed that the material can be a potential candidate for treating NB-contaminated wastewater in the practical setting.

  10. Determination of Methyl tert-Butyl Ether and tert-Butyl Alcohol in Water by Solid-Phase Microextraction/Head Space Analysis in Comparison to EPA Method 5030/8260B

    SciTech Connect

    Oh, Keun-Chan; Stringfellow, William T.

    2003-10-02

    Methyl tert-butyl ether (MTBE) is now one of the most common groundwater contaminants in the United States. Groundwater contaminated with MTBE is also likely to be contaminated with tert-butyl alcohol (TBA), because TBA is a component of commercial grade MTBE, TBA can also be used as a fuel oxygenate, and TBA is a biodegradation product of MTBE. In California, MTBE is subject to reporting at concentrations greater than 3 {micro}g/L. TBA is classified as a ''contaminant of current interest'' and has a drinking water action level of 12 {micro}g/L. In this paper, we describe the development and optimization of a simple, automated solid phase microextraction (SPME) method for the analysis of MTBE and TBA in water and demonstrate the applicability of this method for monitoring MTBE and TBA contamination in groundwater, drinking water, and surface water. In this method, the headspace (HS) of a water sample is extracted with a carboxen/polydimethylsiloxane SPME fiber, the MTBE and TBA are desorbed into a gas chromatograph (GC), and detected using mass spectrometry (MS). The method is optimized for the routine analysis of MTBE and TBA with a level of quantitation of 0.3 {micro}g/L and 4 {micro}g/L, respectively, in water. MTBE quantitation was linear for over two orders of concentration (0.3 {micro}g/L -80 {micro}g/L). TBA was found to be linear within the range of 4 {micro}g/L-7,900 {micro}g/L. The lower level of detection for MTBE is 0.03 {micro}g/L using this method. This SPME method using headspace extraction was found to be advantageous over SPME methods requiring immersion of the fiber into the water samples, because it prolonged the life of the fiber by up to 400 sample analyses. This is the first time headspace extraction SPME has been shown to be applicable to the measurement of both MTBE and TBA at concentrations below regulatory action levels. This method was compared with the certified EPA Method 5030/8260B (purge-and-trap/GC/MS) using split samples from

  11. Integrals of motion from TBA and lattice-conformal dictionary

    NASA Astrophysics Data System (ADS)

    Feverati, Giovanni; Grinza, Paolo

    2004-12-01

    The integrals of motion of the tricritical Ising model are obtained by thermodynamic Bethe ansatz (TBA) equations derived from the A integrable lattice model. They are compared with those given by the conformal field theory leading to a unique one-to-one lattice-conformal correspondence. They can also be followed along the renormalization group flows generated by the action of the boundary field φ on conformal boundary conditions in close analogy to the usual TBA description of energies.

  12. A sustainable slashing industry using biodegradable sizes from modified soy protein to replace petro-based poly(vinyl alcohol).

    PubMed

    Zhao, Yi; Zhao, Yuzhu; Xu, Helan; Yang, Yiqi

    2015-02-17

    Biodegradable sizing agents from triethanolamine (TEA) modified soy protein could substitute poly(vinyl alcohol)(PVA) sizes for high-speed weaving of polyester and polyester/cotton yarns to substantially decrease environmental pollution and impel sustainability of textile industry. Nonbiodegradable PVA sizes are widely used and mainly contribute to high chemical oxygen demand (COD) in textile effluents. It has not been possible to effectively degrade, reuse or replace PVA sizes so far. Soy protein with good biodegradability showed potential as warp sizes in our previous studies. However, soy protein sizes lacked film flexibility and adhesion for required high-speed weaving. Additives with multiple hydroxyl groups, nonlinear molecule, and electric charge could physically modify secondary structure of soy protein and lead to about 23.6% and 43.3% improvement in size adhesion and ability of hair coverage comparing to unmodified soy protein. Industrial weaving results showed TEA-soy protein had relative weaving efficiency 3% and 10% higher than PVA and chemically modified starch sizes on polyester/cotton fabrics, and had relative weaving efficiency similar to PVA on polyester fabrics, although with 3- 6% lower add-on. In addition, TEA-soy sizes had a BOD5/COD ratio of 0.44, much higher than 0.03 for PVA, indicating that TEA-soy sizes were easily biodegradable in activated sludge.

  13. Remediation of environmental pollution by substituting poly(vinyl alcohol) with biodegradable warp size from wheat gluten.

    PubMed

    Chen, Lihong; Reddy, Narendra; Yang, Yiqi

    2013-05-07

    We report the development of wheat gluten as an environmentally friendly sizing agent that can replace poly(vinyl alcohol) (PVA) and make the textile industry more environmentally friendly. Wheat gluten applied onto polyester/cotton (P/C) and polyester as warp sizing agent provided sizing performance and biodegradability in activated sludge necessary to substitute poly(vinyl alcohol) (PVA). PVA is one of the most widely used sizing agents and provides excellent sizing performance to synthetic fibers and their blends but is expensive and difficult to degrade in textile wastewater treatment plants. Although considerable efforts have been made to replace PVA, it has not been possible to develop a warp sizing chemical that can match the sizing performance of PVA and at the same time be cost-effective and biodegrade in effluent treatment plants. At similar % add-on, wheat gluten provided similar cohesion to P/C but much higher abrasion resistance to polyester fabrics compared to PVA. With a biochemical oxygen demand (BOD) to chemical oxygen demand (COD) ratio of 0.7 compared to 0.01 for PVA, wheat gluten was readily degradable in activated sludge. Wheat gluten has the ability to replace PVA for textile warp sizing applications.

  14. Biodegradable microfluidic scaffolds for tissue engineering from amino alcohol-based poly(ester amide) elastomers.

    PubMed

    Wang, Jane; Bettinger, Christopher J; Langer, Robert S; Borenstein, Jeffrey T

    2010-01-01

    Biodegradable polymers with high mechanical strength, flexibility and optical transparency, optimal degradation properties and biocompatibility are critical to the success of tissue engineered devices and drug delivery systems. Most biodegradable polymers suffer from a short half life due to rapid degradation upon implantation, exceedingly high stiffness, and limited ability to functionalize the surface with chemical moieties. This work describes the fabrication of microfluidic networks from poly(ester amide), poly(1,3-diamino-2-hydroxypropane-co-polyol sebacate) (APS), a recently developed biodegradable elastomeric poly(ester amide). Microfluidic scaffolds constructed from APS exhibit a much lower Young's Modulus and a significantly longer degradation half-life than those of previously reported systems. The device is fabricated using a modified replica-molding technique, which is rapid, inexpensive, reproducible, and scalable, making the approach ideal for both rapid prototyping and manufacturing of tissue engineering scaffolds.

  15. Biodegradable microfluidic scaffolds for tissue engineering from amino alcohol-based poly(ester amide) elastomers

    PubMed Central

    Wang, Jane; Bettinger, Christopher J; Langer, Robert S

    2010-01-01

    Biodegradable polymers with high mechanical strength, flexibility and optical transparency, optimal degradation properties and biocompatibility are critical to the success of tissue engineered devices and drug delivery systems. Most biodegradable polymers suffer from a short half-life due to rapid degradation upon implantation, exceedingly high stiffness, and limited ability to functionalize the surface with chemical moieties. This work describes the fabrication of microfluidic networks from poly(ester amide), poly(1,3-diamino-2-hydroxypropane-co-polyol sebacate) (APS), a recently developed biodegradable elastomeric polymer. Microfluidic scaffolds constructed from APS exhibit a much lower Young's modulus and a significantly longer degradation half-life than those of previously reported systems. The device is fabricated using a modified replica-molding technique, which is rapid, inexpensive, reproducible and scalable, making the approach ideal for both rapid prototyping and manufacturing of tissue engineering scaffolds. PMID:21220957

  16. Fully biodegradable airway stents using amino alcohol-based poly(ester amide) elastomers.

    PubMed

    Wang, Jane; Boutin, Kyle G; Abdulhadi, Omar; Personnat, Lyndia D; Shazly, Tarek; Langer, Robert; Channick, Colleen L; Borenstein, Jeffrey T

    2013-10-01

    Airway stents are often used to maintain patency of the tracheal and bronchial passages in patients suffering from central airway obstruction caused by malignant tumors, scarring, and injury. Like most conventional medical implants, they are designed to perform their functions for a limited period of time, after which surgical removal is often required. Two primary types of airway stents are in general use, metal mesh devices and elastomeric tubes; both are constructed using permanent materials, and must be removed when no longer needed, leading to potential complications. This paper describes the development of process technologies for bioresorbable prototype elastomeric airway stents that would dissolve completely after a predetermined period of time or by an enzymatic triggering mechanism. These airway stents are constructed from biodegradable elastomers with high mechanical strength, flexibility and optical transparency. This work combines microfabrication technology with bioresorbable polymers, with the ultimate goal of a fully biodegradable airway stent ultimately capable of improving patient safety and treatment outcomes.

  17. Effect of a commercial alcohol ethoxylate surfactant (C11-15E7) on biodegradation of phenanthrene in a saline water medium by Neptunomonas naphthovorans.

    PubMed

    Li, Jing-Liang; Bai, Renbi

    2005-02-01

    Biodegradation of poorly soluble polycyclic aromatic hydrocarbons (PAHs) has been a challenge in bioremediation. In recent years, surfactant-enhanced bioremediation of PAH contaminants has attracted great attention in research. In this study, biodegradation of phenanthrene as a model PAHs solubilized in saline micellar solutions of a biodegradable commercial alcohol ethoxylate nonionic surfactant was investigated. The critical micelle concentration (CMC) of the surfactant and its solubilization capacity for phenanthrene were examined in an artificial saline water medium, and a type of marine bacteria, Neptunomonas naphthovorans, was studied for the biodegradation of phenanthrene solubilized in the surfactant micellar solutions of the saline medium. It is found that the solubility of phenanthrene in the surfactant micellar solutions increased linearly with the surfactant concentrations, but, at a fixed phenanthrene concentration, the biodegradability of phenanthrene in the micellar solutions decreased with the increase of the surfactant concentrations. This was attributed to the reduced bioavailability of phenanthrene, due to its increased solubilization extent in the micellar phase and possibly lowered mass transfer rate from the micellar phase into the aqueous phase or into the bacterial cells. In addition, an inhibitory effect of the surfactant on the bacterial growth at high surfactant concentrations may also play a role. It is concluded that the surfactant largely enhanced the solubilization of phenanthrene in the saline water medium, but excess existence of the surfactant in the medium should be minimized or avoided for the biodegradation of phenanthrene by Neptunomonas naphthovorans.

  18. USING STABLE CARBON ISOTOPES TO ESTIMATE THE RATE OF NATURAL BIODEGRADATION OF MTBE AT FIELD SCALE

    EPA Science Inventory

    Natural biodegradation of fuel contaminants in ground water reduces the risk of contamination of drinking water wells. It is very difficult to estimate the natural rate of biodegradation of MTBE in ground water because its primary biodegradation product, TBA, is also a component...

  19. Effect of redox conditions on MTBE biodegradation in surface water Sediments

    USGS Publications Warehouse

    Bradley, P.M.; Chapelle, F.H.; Landmeyer, J.E.

    2001-01-01

    Microbial degradation of methyl tert-butyl ether (MTBE) was observed in surface water-sediment microcosms under anaerobic conditions. The efficiency and products of anaerobic MTBE biodegradation were dependent on the predominant terminal electron-accepting conditions. In the presence of substantial methanogenic activity, MTBE biodegradation was nominal and involved reduction of MTBE to the toxic product, tert-butyl alcohol (TBA). In the absence of significant methanogenic activity, accumulation of [14C]TBA generally decreased, and mineralization of [U-14C]MTBE to 14CO2 generally increased as the oxidative potential of the predominant terminal electron acceptor increased in the order of SO4, Fe(III), Mn(IV) < NO3 < O2. Microbial mineralization of MTBE to CO2 under Mn(IV)or SO4-reducing conditions has not been reported previously. The results of this study indicate that microorganisms inhabiting the sediments of streams and lakes can degrade MTBE effectively under a range of anaerobic terminal electron-accepting conditions. Thus, anaerobic bed sediment microbial processes may provide a significant environmental sink for MTBE in surface water systems throughout the United States.

  20. IS HCI THAT IS USED AS A PRESERVATIVE CREATING FALSE POSITIVES FOR TBA IN GROUND WATER

    EPA Science Inventory

    Will hydrochloric acid produce false positives for TBA? Yes, if you heat the sample to get a lower detection limit for TBA. Conventional purge and trap methods at ambient temperature have a reporting limit for TBA between 50 and 100 g/liter. This is higher than the provisiona...

  1. Microbial biosafety of pilot-scale bioreactor treating MTBE and TBA-contaminated drinking water supply.

    PubMed

    Schmidt, Radomir; Klemme, David A; Scow, Kate; Hristova, Krassimira

    2012-03-30

    A pilot-scale sand-based fluidized bed bioreactor (FBBR) was utilized to treat both methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) from a contaminated aquifer. To evaluate the potential for re-use of the treated water, we tested for a panel of water quality indicator microorganisms and potential waterborne pathogens including total coliforms, Escherichia coli, Salmonella and Shigella spp., Campylobacter jejuni, Aeromonas hydrophila, Legionella pneumophila, Vibrio cholerae, Yersinia enterocolytica and Mycobacterium avium in both influent and treated waters from the bioreactor. Total bacteria decreased during FBBR treatment. E. coli, Salmonella and Shigella spp., C. jejuni, V. cholerae, Y. enterocolytica and M. avium were not detected in aquifer water or bioreactor treated water samples. For those pathogens detected, including total coliforms, L. pneumophila and A. hydrophila, numbers were usually lower in treated water than influent samples, suggesting removal during treatment. The detection of particular bacterial species reflected their presence or absence in the influent waters.

  2. ENRICHMENT OF STABLE CARBON AND HYDROGEN ISOTOPES DURING ANAEROBIC BIODEGRADATION OF MTBE-MICROCOSM AND FIELD EVIDENCE

    EPA Science Inventory

    The conventional approach to evaluate biodegradation of organic contaminants in ground water is to demonstrate an increase in the concentration of transformation products. This approach is problematic for MTBE from gasoline spills because the primary transformation product (TBA) ...

  3. Review of quantitative surveys of the length and stability of MTBE, TBA, and benzene plumes in groundwater at UST sites.

    PubMed

    Connor, John A; Kamath, Roopa; Walker, Kenneth L; McHugh, Thomas E

    2015-01-01

    Quantitative information regarding the length and stability condition of groundwater plumes of benzene, methyl tert-butyl ether (MTBE), and tert-butyl alcohol (TBA) has been compiled from thousands of underground storage tank (UST) sites in the United States where gasoline fuel releases have occurred. This paper presents a review and summary of 13 published scientific surveys, of which 10 address benzene and/or MTBE plumes only, and 3 address benzene, MTBE, and TBA plumes. These data show the observed lengths of benzene and MTBE plumes to be relatively consistent among various regions and hydrogeologic settings, with median lengths at a delineation limit of 10 µg/L falling into relatively narrow ranges from 101 to 185 feet for benzene and 110 to 178 feet for MTBE. The observed statistical distributions of MTBE and benzene plumes show the two plume types to be of comparable lengths, with 90th percentile MTBE plume lengths moderately exceeding benzene plume lengths by 16% at a 10-µg/L delineation limit (400 feet vs. 345 feet) and 25% at a 5-µg/L delineation limit (530 feet vs. 425 feet). Stability analyses for benzene and MTBE plumes found 94 and 93% of these plumes, respectively, to be in a nonexpanding condition, and over 91% of individual monitoring wells to exhibit nonincreasing concentration trends. Three published studies addressing TBA found TBA plumes to be of comparable length to MTBE and benzene plumes, with 86% of wells in one study showing nonincreasing concentration trends.

  4. Synthesis, characterization and application of biodegradable crosslinked carboxymethyl chitosan/poly(vinyl alcohol) clay nanocomposites.

    PubMed

    Sabaa, Magdy W; Abdallah, Heba M; Mohamed, Nadia A; Mohamed, Riham R

    2015-11-01

    Crosslinked poly(vinyl alcohol) (PVA)/carboxymethyl chitosan (CMCh) nanocomposites were synthesized using terephthaloyl diisothiocyanate crosslinker, in the presence of montmorillonite (MMT), in different ratios of the two matrices. Characterization of nanocomposites was performed using different analyses. Swelling behavior was studied in different buffered solutions. It was found that formation of crosslinked CMCh/PVA hydrogels increased the swellability. Metal ion adsorption has also been investigated. The results indicated that crosslinked CMCh adsorbs various metal ions much more than non crosslinked CMCh. Antimicrobial activity was examined against Gram positive bacteria, against Gram negative bacteria, and also against fungi. Results indicated that most of these nanocomposites exhibited good antimicrobial potency. Degradation study was carried out in Simulated Body Fluid (SBF) for different time periods in order to find out degradation index (Di). Results showed that weight loss of most of the nanocomposites increased as a function of incubation time.

  5. Formation of alkenes via degradation of tert-alkyl ethers and alcohols by Aquincola tertiaricarbonis L108 and Methylibium spp.

    PubMed

    Schäfer, Franziska; Muzica, Liudmila; Schuster, Judith; Treuter, Naemi; Rosell, Mònica; Harms, Hauke; Müller, Roland H; Rohwerder, Thore

    2011-09-01

    Bacterial degradation pathways of fuel oxygenates such as methyl tert-butyl and tert-amyl methyl ether (MTBE and TAME, respectively) have already been studied in some detail. However, many of the involved enzymes are still unknown, and possible side reactions have not yet been considered. In Aquincola tertiaricarbonis L108, Methylibium petroleiphilum PM1, and Methylibium sp. strain R8, we have now detected volatile hydrocarbons as by-products of the degradation of the tert-alkyl ether metabolites tert-butyl and tert-amyl alcohol (TBA and TAA, respectively). The alkene isobutene was formed only during TBA catabolism, while the beta and gamma isomers of isoamylene were produced only during TAA conversion. Both tert-alkyl alcohol degradation and alkene production were strictly oxygen dependent. However, the relative contribution of the dehydration reaction to total alcohol conversion increased with decreasing oxygen concentrations. In resting-cell experiments where the headspace oxygen content was adjusted to less than 2%, more than 50% of the TAA was converted to isoamylene. Isobutene formation from TBA was about 20-fold lower, reaching up to 4% alcohol turnover at low oxygen concentrations. It is likely that the putative tert-alkyl alcohol monooxygenase MdpJ, belonging to the Rieske nonheme mononuclear iron enzymes and found in all three strains tested, or an associated enzymatic step catalyzed the unusual elimination reaction. This was also supported by the detection of mdpJK genes in MTBE-degrading and isobutene-emitting enrichment cultures obtained from two treatment ponds operating at Leuna, Germany. The possible use of alkene formation as an easy-to-measure indicator of aerobic fuel oxygenate biodegradation in contaminated aquifers is discussed.

  6. USING δ13C TO PREDICT THE RATE OF BIODEGRADATION OF MTBE

    EPA Science Inventory

    It is difficult to estimate the rate of natural biodegradation of MTBE at field scale. Dispersion in the aquifer or dilution in the well can give a false impression of attenuation along a flow path. The first product of MTBE biodegradation is TBA. Many gasoline spills contain TB...

  7. Alcohol

    MedlinePlus

    ... that's how many accidents occur. continue What Is Alcoholism? What can be confusing about alcohol is that ... develop a problem with it. Sometimes, that's called alcoholism (say: al-kuh-HOL - ism) or being an ...

  8. Alcohol

    MedlinePlus

    If you are like many Americans, you drink alcohol at least occasionally. For many people, moderate drinking ... risky. Heavy drinking can lead to alcoholism and alcohol abuse, as well as injuries, liver disease, heart ...

  9. Formation of Alkenes via Degradation of tert-Alkyl Ethers and Alcohols by Aquincola tertiaricarbonis L108 and Methylibium spp. ▿†

    PubMed Central

    Schäfer, Franziska; Muzica, Liudmila; Schuster, Judith; Treuter, Naemi; Rosell, Mònica; Harms, Hauke; Müller, Roland H.; Rohwerder, Thore

    2011-01-01

    Bacterial degradation pathways of fuel oxygenates such as methyl tert-butyl and tert-amyl methyl ether (MTBE and TAME, respectively) have already been studied in some detail. However, many of the involved enzymes are still unknown, and possible side reactions have not yet been considered. In Aquincola tertiaricarbonis L108, Methylibium petroleiphilum PM1, and Methylibium sp. strain R8, we have now detected volatile hydrocarbons as by-products of the degradation of the tert-alkyl ether metabolites tert-butyl and tert-amyl alcohol (TBA and TAA, respectively). The alkene isobutene was formed only during TBA catabolism, while the beta and gamma isomers of isoamylene were produced only during TAA conversion. Both tert-alkyl alcohol degradation and alkene production were strictly oxygen dependent. However, the relative contribution of the dehydration reaction to total alcohol conversion increased with decreasing oxygen concentrations. In resting-cell experiments where the headspace oxygen content was adjusted to less than 2%, more than 50% of the TAA was converted to isoamylene. Isobutene formation from TBA was about 20-fold lower, reaching up to 4% alcohol turnover at low oxygen concentrations. It is likely that the putative tert-alkyl alcohol monooxygenase MdpJ, belonging to the Rieske nonheme mononuclear iron enzymes and found in all three strains tested, or an associated enzymatic step catalyzed the unusual elimination reaction. This was also supported by the detection of mdpJK genes in MTBE-degrading and isobutene-emitting enrichment cultures obtained from two treatment ponds operating at Leuna, Germany. The possible use of alkene formation as an easy-to-measure indicator of aerobic fuel oxygenate biodegradation in contaminated aquifers is discussed. PMID:21742915

  10. Alcohol

    MedlinePlus

    ... de los dientes Video: Getting an X-ray Alcohol KidsHealth > For Kids > Alcohol Print A A A What's in this article? ... What Is Alcoholism? Say No en español El alcohol Getting the Right Message "Hey, who wants a ...

  11. Microbial biosafety of pilot-scale bioreactor treating MTBE and TBA-contaminated drinking water supply

    PubMed Central

    Schmidt, Radomir; Klemme, David A.; Scow, Kate; Hristova, Krassimira

    2012-01-01

    A pilot-scale sand-based fluidized bed bioreactor (FBBR) was utilized to treat both methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA) from a contaminated aquifer. To evaluate the potential for re-use of the treated water, we tested for a panel of water quality indicator microorganisms and potential waterborne pathogens including total coliforms, E. coli, Salmonella and Shigella spp., Campylobacter jejuni, Aeromonas hydrophila, Legionella pneumophila, Vibrio cholerae, Yersinia enterocolytica and Mycobacterium avium in both influent and treated waters from the bioreactor. Total bacteria decreased during FBBR treatment. E. coli, Salmonella and Shigella spp., C. jejuni, V. cholerae, Y. enterocolytica and M. avium were not detected in aquifer water or bioreactor treated water samples. For those pathogens detected, including total coliforms, L. pneumophila and A. hydrophila, numbers were usually lower in treated water than influent samples, suggesting removal during treatment. The detection of particular bacterial species reflected their presence or absence in the influent waters. PMID:22321859

  12. Alcohol

    MedlinePlus

    ... parents and other adults use alcohol socially — having beer or wine with dinner, for example — alcohol seems ... besides just hanging out in someone's basement drinking beer all night. Plan a trip to the movies, ...

  13. Alcoholism.

    ERIC Educational Resources Information Center

    Caliguri, Joseph P., Ed.

    This extensive annotated bibliography provides a compilation of documents retreived from a computerized search of the ERIC, Social Science Citation Index, and Med-Line databases on the topic of alcoholism. The materials address the following areas of concern: (1) attitudes toward alcohol users and abusers; (2) characteristics of alcoholics and…

  14. Development of highly porous biodegradable γ-Fe2O3/polyvinyl alcohol nanofiber mats using electrospinning process for biomedical application.

    PubMed

    Ngadiman, Nor Hasrul Akhmal; Yusof, Noordin Mohd; Idris, Ani; Misran, Effaliza; Kurniawan, Denni

    2017-01-01

    The use of electrospinning process in fabricating tissue engineering scaffolds has received great attention in recent years due to its simplicity. The nanofibers produced via electrospinning possessed morphological characteristics similar to extracellular matrix of most tissue components. Porosity plays a vital role in developing tissue engineering scaffolds because it influences the biocompatibility performance of the scaffolds. In this study, maghemite (γ-Fe2O3) was mixed with polyvinyl alcohol (PVA) and subsequently electrospun to produce nanofibers. Five factors; nanoparticles content, voltage, flow rate, spinning distance, and rotating speed were varied to produce the electrospun nanofibrous mats with high porosity value. Empirical model was developed using response surface methodology to analyze the effect of these factors to the porosity. The results revealed that the optimum porosity (90.85%) was obtained using 5% w/v nanoparticle content, 35kV of voltage, 1.1ml/h volume flow rate of solution, 8cm spinning distance and 2455rpm of rotating speed. The empirical model was verified successfully by performing confirmation experiments. The properties of optimum PVA/γ-Fe2O3 nanofiber mats such as fiber diameter, mechanical properties, and contact angle were investigated. In addition, cytocompatibility test, in vitro degradation rate, and MTT assay were also performed. Results revealed that high porosity biodegradable γ-Fe2O3/polyvinyl alcohol nanofiber mats have low mechanical properties but good degradation rates and cytocompatibility properties. Thus, they are suitable for low load bearing biomedical application or soft tissue engineering scaffold.

  15. Alcohol

    MedlinePlus

    ... created when grains, fruits, or vegetables are fermented . Fermentation is a process that uses yeast or bacteria ... change the sugars in the food into alcohol. Fermentation is used to produce many necessary items — everything ...

  16. Alcohol.

    ERIC Educational Resources Information Center

    Schibeci, Renato

    1996-01-01

    Describes the manufacturing of ethanol, the effects of ethanol on the body, the composition of alcoholic drinks, and some properties of ethanol. Presents some classroom experiments using ethanol. (JRH)

  17. Effect of electron beam radiation processing on mechanical and thermal properties of fully biodegradable crops straw/poly (vinyl alcohol) biocomposites

    NASA Astrophysics Data System (ADS)

    Guo, Dan

    2017-01-01

    Fully biodegradable biocomposites based on crops straw and poly(vinyl alcohol) was prepared through thermal processing, and the effect of electron beam radiation processing with N,N-methylene double acrylamide as radiation sensitizer on mechanical and thermal properties of the biocomposites were investigated. The results showed that, when the radiation dose were in the range of 0-50 kGy, the mechanical and thermal properties of the biocomposites could be improved significantly through the electron beam radiation processing, and the interface compatibility was also improved because of the formation of stable cross-linked network structure, when the radiation dose were above the optimal value (50 kGy), the comprehensive properties of the biocomposites were gradually destroyed. EB radiation processing could be used as an effective technology to improve the comprehensive performance of the biocomposites, and as a green and efficient processing technology, radiation processing takes place at room temperature, and no contamination and by-product are possible.

  18. MONITORED NATURAL ATTENUATION OF TERTIARY BUTYL ALCOHOL (TBA) IN GROUND WATER AT GASOLINE SPILL SITES

    EPA Science Inventory

    The state agencies that implement the Underground Storage Tank program rely heavily on Monitored Natural Attenuation (MNA) to clean up contaminants such as benzene and methyl tertiary butyl ether (MTBE) at gasoline spill sites. This is possible because the contaminants are biolo...

  19. MONITORED NATURAL ATTENUATION AND RISK MANAGEMENT OF MTBE AND TBA IN GROUND WATER

    EPA Science Inventory

    Monitored natural attenuation (as U.S. EPA defines the term) is a remedy, where natural processes bring the concentration of MTBE or TBA to an acceptable level in a reasonable period of time. The longevity of the plume is its critical property. The rate of attenuation is typica...

  20. The standing wave FEL/TBA: Realistic cavity geometry and energy extraction

    SciTech Connect

    Kim, Jin-Soo, Henke, H.; Sessler, A.M.; Sharp, W.M.

    1993-05-01

    A set of parameters for standing wave free electron laser two beam accelerators (SWFEL/TBA) is evaluated for realistic cavity geometry taking into account beam-break-up and the sensitivity of output power to imperfections. Also given is a power extraction system using cavity coupled wave guides.

  1. Biodegradation behaviors and water adsorption of poly(vinyl alcohol)/starch/carboxymethyl cellulose/clay nanocomposites

    NASA Astrophysics Data System (ADS)

    Taghizadeh, Mohammad Taghi; Sabouri, Narges

    2013-09-01

    The focus of this work is to study the effect of sodium montmorillonite (MMT-Na) clay content on the rate and extent of enzymatic hydrolysis polyvinyl alcohol (PVA)/starch (S)/carboxymethyl cellulose (CMC) blends using enzyme cellulase. The rate of glucose production from each nanocomposite substrates was most rapid for the substrate without MMT-Na and decreased with the addition of MMT-Na for PVA/S/CMC blend (51.5 μg/ml h), PVA/S/CMC/1% MMT (45.4 μg/ml h), PVA/S/CMC/3% MMT (42.8 μg/ml h), and PVA/S/CMC/5% MMT (39.2 μg/ml h). The results of this study have revealed that films with MMT-Na content at 5 wt.% exhibited a significantly reduced rate and extent of hydrolysis. Enzymatic degradation behavior of MMT-Na containing nanocomposites of PVA/S/CMC was based on the determinations of weight loss and the reducing sugars. The degraded residues have been characterized by various analytical techniques, such as Fourier transform infrared spectroscopy, scanning electronic microscopy, and UV-vis spectroscopy.

  2. Biodegradable plastics from renewable sources.

    PubMed

    Flieger, M; Kantorová, M; Prell, A; Rezanka, T; Votruba, J

    2003-01-01

    Plastic waste disposal is a huge ecotechnological problem and one of the approaches to solving this problem is the development of biodegradable plastics. This review summarizes data on their use, biodegradability, commercial reliability and production from renewable resources. Some commercially successful biodegradable plastics are based on chemical synthesis (i.e. polyglycolic acid, polylactic acid, polycaprolactone, and polyvinyl alcohol). Others are products of microbial fermentations (i.e. polyesters and neutral polysaccharides) or are prepared from chemically modified natural products (e.g., starch, cellulose, chitin or soy protein).

  3. Biodegradation of methyl tert-butyl ether and other fuel oxygenates by a new strain, Mycobacterium austroafricanum IFP 2012.

    PubMed

    François, Alan; Mathis, Hugues; Godefroy, Davy; Piveteau, Pascal; Fayolle, Françoise; Monot, Frédéric

    2002-06-01

    A strain that efficiently degraded methyl tert-butyl ether (MTBE) was obtained by initial selection on the recalcitrant compound tert-butyl alcohol (TBA). This strain, a gram-positive methylotrophic bacterium identified as Mycobacterium austroafricanum IFP 2012, was also able to degrade tert-amyl methyl ether and tert-amyl alcohol. Ethyl tert-butyl ether was weakly degraded. tert-Butyl formate and 2-hydroxy isobutyrate (HIBA), two intermediates in the MTBE catabolism pathway, were detected during growth on MTBE. A positive effect of Co2+ during growth of M. austroafricanum IFP 2012 on HIBA was demonstrated. The specific rate of MTBE degradation was 0.6 mmol/h/g (dry weight) of cells, and the biomass yield on MTBE was 0.44 g (dry weight) per g of MTBE. MTBE, TBA, and HIBA degradation activities were induced by MTBE and TBA, and TBA was a good inducer. Involvement of at least one monooxygenase during degradation of MTBE and TBA was shown by (i) the requirement for oxygen, (ii) the production of propylene epoxide from propylene by MTBE- or TBA- grown cells, and (iii) the inhibition of MTBE or TBA degradation and of propylene epoxide production by acetylene. No cytochrome P-450 was detected in MTBE- or TBA-grown cells. Similar protein profiles were obtained after sodium dodecyl sulfate-polyacrylamide gel electrophoresis of crude extracts from MTBE- and TBA-grown cells. Among the polypeptides induced by these substrates, two polypeptides (66 and 27 kDa) exhibited strong similarities with known oxidoreductases.

  4. Computer experiments on aqueous solutions. VI. Potential energy function for tert-butyl alcohol dimer and molecular dynamics calculation of 3 mol % aqueous solution of tert-butyl alcohol

    NASA Astrophysics Data System (ADS)

    Tanaka, Hideki; Nakanishi, Koichiro; Touhara, Hidekazu

    1984-11-01

    Molecular dynamics (MD) calculation has been carried out for a dilute aqueous solution of tert-butyl alcohol (TBA) at 298.15 K and with experimental density value by the use of constant temperature technique developed previously. The total number of molecule is 216, seven of which are TBA. The mole fraction of TBA is thus 0.032. For water-water and TBA-water interactions, the MCY (Matsuoka-Clementi-Yoshimine) potential and previously reported potential determined by MO calculation are used. A new potential for TBA-TBA is determined by ab initio LCAO SCF calculations for more than 500 different configurations with an STO-3G basis set and subsequent multiparameter fitting of the MO data to a 12-6-3-1 type potential energy function. The MD calculation is extended up to 84 000 time steps (26 ps) and final 60 000 time steps are used to calculate both static and dynamic properties of the system. Both hydrophobic hydration and interaction due to TBA molecules are proved to be stronger than those of methanol studied previously. Structural promotion of water is clearly observed in radial distribution functions and trajectories of each molecule. The configuration and trajectory of all the molecules in solution indicate clearly the association of TBA molecules. It is also found from pair interaction distribution functions that no hydrogen bonding interaction occurs between two TBA molecules. The self-diffusion coefficient of water in the solution is appreciably smaller than that in pure water.

  5. Modeling the microscopic electrical properties of thrombin binding aptamer (TBA) for label-free biosensors

    NASA Astrophysics Data System (ADS)

    Alfinito, Eleonora; Reggiani, Lino; Cataldo, Rosella; De Nunzio, Giorgio; Giotta, Livia; Guascito, Maria Rachele

    2017-02-01

    Aptamers are chemically produced oligonucleotides, able to bind a variety of targets such as drugs, proteins and pathogens with high sensitivity and selectivity. Therefore, aptamers are largely employed for producing label-free biosensors (aptasensors), with significant applications in diagnostics and drug delivery. In particular, the anti-thrombin aptamers are biomolecules of high interest for clinical use, because of their ability to recognize and bind the thrombin enzyme. Among them, the DNA 15-mer aptamer (TBA), has been widely explored around the possibility of using it in aptasensors. This paper proposes a microscopic model of the electrical properties of TBA and of the aptamer-thrombin complex, combining information from both structure and function, following the issues addressed in an emerging branch of electronics known as proteotronics. The theoretical results are compared and validated with measurements reported in the literature. Finally, the model suggests resistance measurements as a novel tool for testing aptamer-target affinity.

  6. Modeling the microscopic electrical properties of thrombin binding aptamer (TBA) for label-free biosensors.

    PubMed

    Alfinito, Eleonora; Reggiani, Lino; Cataldo, Rosella; De Nunzio, Giorgio; Giotta, Livia; Guascito, Maria Rachele

    2017-02-10

    Aptamers are chemically produced oligonucleotides, able to bind a variety of targets such as drugs, proteins and pathogens with high sensitivity and selectivity. Therefore, aptamers are largely employed for producing label-free biosensors (aptasensors), with significant applications in diagnostics and drug delivery. In particular, the anti-thrombin aptamers are biomolecules of high interest for clinical use, because of their ability to recognize and bind the thrombin enzyme. Among them, the DNA 15-mer aptamer (TBA), has been widely explored around the possibility of using it in aptasensors. This paper proposes a microscopic model of the electrical properties of TBA and of the aptamer-thrombin complex, combining information from both structure and function, following the issues addressed in an emerging branch of electronics known as proteotronics. The theoretical results are compared and validated with measurements reported in the literature. Finally, the model suggests resistance measurements as a novel tool for testing aptamer-target affinity.

  7. Site specific replacements of a single loop nucleoside with a dibenzyl linker may switch the activity of TBA from anticoagulant to antiproliferative

    PubMed Central

    Scuotto, Maria; Rivieccio, Elisa; Varone, Alessia; Corda, Daniela; Bucci, Mariarosaria; Vellecco, Valentina; Cirino, Giuseppe; Virgilio, Antonella; Esposito, Veronica; Galeone, Aldo; Borbone, Nicola; Varra, Michela; Mayol, Luciano

    2015-01-01

    Many antiproliferative G-quadruplexes (G4s) arise from the folding of GT-rich strands. Among these, the Thrombin Binding Aptamer (TBA), as a rare example, adopts a monomolecular well-defined G4 structure. Nevertheless, the potential anticancer properties of TBA are severely hampered by its anticoagulant action and, consequently, no related studies have appeared so far in the literature. We wish to report here that suitable chemical modifications in the TBA sequence can preserve its antiproliferative over anticoagulant activity. Particularly, we replaced one residue of the TT or TGT loops with a dibenzyl linker to develop seven new quadruplex-forming TBA based sequences (TBA-bs), which were studied for their structural (CD, CD melting, 1D NMR) and biological (fibrinogen, PT and MTT assays) properties. The three-dimensional structures of the TBA-bs modified at T13 (TBA-bs13) or T12 (TBA-bs12), the former endowed with selective antiproliferative activity, and the latter acting as potently as TBA in both coagulation and MTT assays, were further studied by 2D NMR restrained molecular mechanics. The comparative structural analyses indicated that neither the stability, nor the topology of the G4s, but the different localization of the two benzene rings of the linker was responsible for the loss of the antithrombin activity for TBA-bs13. PMID:26250112

  8. Methyl tert-butyl ether and tert-butyl alcohol degradation by Fusarium solani.

    PubMed

    Magaña-Reyes, Miguel; Morales, Marcia; Revah, Sergio

    2005-11-01

    Fusarium solani degraded methyl tert-butyl ether (MTBE) and other oxygenated compounds from gasoline including tert-butyl alcohol (TBA). The maximum degradation rate of MTBE was 16 mg protein h and 46 mg/g protein h for TBA. The culture transformed 77% of the total carbon to 14CO2. The estimated yield for MTBE was 0.18 g dry wt/g MTBE.

  9. Biodegradation of methyl tert-butyl ether by cometabolism with hexane in biofilters inoculated with Pseudomonas aeruginosa.

    PubMed

    Salazar, Margarita; Morales, Marcia; Revah, Sergio

    2012-01-01

    Biodegradation of methyl tert-butyl ether (MTBE) vapors by cometabolism with gaseous hexane (n-hexane > 95%) was investigated using Pseudomonas aeruginosa utilizing short chain aliphatic hydrocarbon (C(5)-C(8)). Kinetic batch experiments showed that MTBE was degraded even when hexane was completely exhausted with a cometabolic coefficient of 1.06 ± 0.16 mg MTBE mg hexane(-1). Intermediate tert-butyl alcohol (TBA) accumulation was observed followed by its gradual consumption. A maximum MTBE elimination capacity (EC(MAX)) of 35 g m(-3) h(-1) and removal efficiency (RE) of 70% were attained in mineral medium amended biofilters having an empty bed residence time (EBRT) of 1 min. For these experimental conditions, a maximum hexane EC of approximately 60 g m(-3) h(-1) was obtained at a load of 75 g m(-3) h(-1). Experiments under transient conditions revealed a competitive substrate interaction between MTBE and hexane. Biomass densities between 5.8 and 12.6 g L(biofilter) (-1) were obtained. Nevertheless, production of biopolymers caused non-uniform distribution flow rates that reduced the performance. Residence time distribution profiles showed an intermediate dispersion flow rate with a dispersion coefficient of 0.8 cm(2) s(-1).

  10. Longitudinal impedance measurement of an RK-TBA induction accelerating gap

    SciTech Connect

    Eylon, S.; Henestroza, E.; Kim, J.-S.; Houck, T.L.; Westenskow, G.A.; Yu, S.S.

    1997-05-01

    Induction accelerating gap designs are being studied for Relativistic Klystron Two-Beam Accelerator (RK-TBA) applications. The accelerating gap has to satisfy the following major requirements: hold-off of the applied accelerating voltage pulse, low transverse impedance to limit beam breakup, low longitudinal impedance at the beam-modulation frequency to minimize power loss. Various gap geometries, materials and novel insulating techniques were explored to optimize the gap design. We report on the experimental effort to evaluate the rf properties of the accelerating gaps in a simple pillbox cavity structure. The experimental cavity setup was designed using the AMOS, MAFIA and URMEL numerical codes. Longitudinal impedance measurements above beam-tube cut-off frequency using a single-wire measuring system are presented.

  11. Biodegradation of Methyl Tertiary Butyl Ether (MTBE) by a Microbial Consortium in a Continuous Up-Flow Packed-Bed Biofilm Reactor: Kinetic Study, Metabolite Identification and Toxicity Bioassays

    PubMed Central

    Alfonso-Gordillo, Guadalupe; Flores-Ortiz, César Mateo; Morales-Barrera, Liliana

    2016-01-01

    This study investigated the aerobic biodegradation of methyl tertiary-butyl ether (MTBE) by a microbial consortium in a continuous up-flow packed-bed biofilm reactor using tezontle stone particles as a supporting material for the biofilm. Although MTBE is toxic for microbial communities, the microbial consortium used here was able to resist MTBE loading rates up to 128.3 mg L-1 h-1, with removal efficiencies of MTBE and chemical oxygen demand (COD) higher than 90%. A linear relationship was observed between the MTBE loading rate and the MTBE removal rate, as well as between the COD loading rate and the COD removal rate, within the interval of MTBE loading rates from 11.98 to 183.71 mg L-1 h-1. The metabolic intermediate tertiary butyl alcohol (TBA) was not detected in the effluent during all reactor runs, and the intermediate 2-hydroxy butyric acid (2-HIBA) was only detected at MTBE loading rates higher than 128.3 mg L-1 h-1. The results of toxicity bioassays with organisms from two different trophic levels revealed that the toxicity of the influent was significantly reduced after treatment in the packed-bed reactor. The packed-bed reactor system used in this study was highly effective for the continuous biodegradation of MTBE and is therefore a promising alternative for detoxifying MTBE-laden wastewater and groundwater. PMID:27907122

  12. Behavior of DNAPL mixture of organometallic and chlorinated solvent in the presence of surfactants and alcohols as density modifying agents.

    PubMed

    Talawat, Jaruwan; Sabatini, David A; Tongcumpou, Chantra

    2013-01-01

    This work evaluates the behavior of surfactant and alcohols in combination with a mixture of tributyltinchloride (TBT) and tetrachloroethylene (PCE) with the goal of modifying the mixed oil from being a dense non-aqueous phase liquid (DNAPL) to a light non-aqueous phase liquid (LNAPL). Phase behavior of the mixed oil was studied under various combinations of surfactant, alcohol, and salinity. Phase density conversion was examined using pseudo-ternary phase diagrams constructed between the mixed oil, surfactant solution (4 wt%), and two types of alcohols (n-butyl alcohol (BuOH) and tert-butyl alcohol (TBA)). Aqueous phase solubilization and oil phase density modification were studied at varying alcohol to surfactant (A/S) ratios. The results showed that the optimum surfactant system was sodium dihexylsulfosuccinate (SDHS) and hexadecyl diphenyloxidedisulfonate (C16DPDS) (3.6 wt% and 0.4 wt%, respectively) with salt (NaCl) of 3 wt%. From pseudo-ternary phase diagrams, BuOH was found to produce a larger LNAPL region than TBA. From solubilization studies, the surfactant system plus either TBA or BuOH caused PCE preferential solubilization and this preference was more pronounced at higher total surfactant concentration in the system with TBA addition. In terms of density modification, BuOH produced lower oil density than TBA at high A/S ratio. This phase behavior knowledge can be used to optimize site remediation of organometallic DNAPLs.

  13. Aerobic mineralization of MTBE and tert-butyl alcohol by stream-bed sediment microorganisms

    USGS Publications Warehouse

    Bradley, P.M.; Landmeyer, J.E.; Chapelle, F.H.

    1999-01-01

    Microorganisms indigenous to the stream-bed sediments at two gasoline- contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.Microorganisms indigenous to the stream-bed sediments at two gasoline-contaminated groundwater sites demonstrated significant mineralization of the fuel oxygenates, methyl tert-butyl ether (MTBE) and tert-butyl alcohol (TBA). Up to 73% of [U-14C]-MTBE and 84% of [U-14C]-TBA were degraded to 14CO2 under mixed aerobic/anaerobic conditions. No significant mineralization was observed under strictly anaerobic conditions. The results indicate that, under the mixed aerobic/anaerobic conditions characteristic of stream-bed sediments, microbial processes may provide a significant environmental sink for MTBE and TBA delivered to surface water bodies by contaminated groundwater or by other sources.

  14. Design and Control of Glycerol-tert-Butyl Alcohol Etherification Process

    PubMed Central

    Vlad, Elena; Bozga, Grigore

    2012-01-01

    Design, economics, and plantwide control of a glycerol-tert-butyl alcohol (TBA) etherification plant are presented. The reaction takes place in liquid phase, in a plug flow reactor, using Amberlyst 15 as a catalyst. The products' separation is achieved by two distillation columns where high-purity ethers are obtained and a section involving extractive distillation with 1,4-butanediol as solvent, which separates TBA from the TBA/water azeotrope. Details of design performed in AspenPlus and an economic evaluation of the process are given. Three plantwide control structures are examined using a mass balance model of the plant. The preferred control structure fixes the fresh glycerol flow rate and the ratio glycerol + monoether : TBA at reactor-inlet. The stability and robustness in the operation are checked by rigorous dynamic simulation in AspenDynamics. PMID:23365512

  15. Design and control of glycerol-tert-butyl alcohol etherification process.

    PubMed

    Vlad, Elena; Bildea, Costin Sorin; Bozga, Grigore

    2012-01-01

    Design, economics, and plantwide control of a glycerol-tert-butyl alcohol (TBA) etherification plant are presented. The reaction takes place in liquid phase, in a plug flow reactor, using Amberlyst 15 as a catalyst. The products' separation is achieved by two distillation columns where high-purity ethers are obtained and a section involving extractive distillation with 1,4-butanediol as solvent, which separates TBA from the TBA/water azeotrope. Details of design performed in AspenPlus and an economic evaluation of the process are given. Three plantwide control structures are examined using a mass balance model of the plant. The preferred control structure fixes the fresh glycerol flow rate and the ratio glycerol + monoether : TBA at reactor-inlet. The stability and robustness in the operation are checked by rigorous dynamic simulation in AspenDynamics.

  16. Extruded/injection-molded composites containing unripe plantain flour, ethylene vinyl-alcohol and glycerol: Evaluation of color, mechanical property and biodegradability

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Extruded/injection-molded composites were produced from plantain flour blended with ethylene vinyl-alcohol (EVA) and glycerol. Scanning electron microscopy showed composites had a smooth surface and excellent compatibility between plantain flour, EVA and glycerol. The impact of increased plantain fl...

  17. Alcoholism and Alcohol Abuse

    MedlinePlus

    ... their drinking causes distress and harm. It includes alcoholism and alcohol abuse. Alcoholism, or alcohol dependence, is a disease that causes ... groups. NIH: National Institute on Alcohol Abuse and Alcoholism

  18. Biodegradable polydepsipeptides.

    PubMed

    Feng, Yakai; Guo, Jintang

    2009-02-01

    This paper reviews the synthesis, characterization, biodegradation and usage of bioresorbable polymers based on polydepsipeptides. The ring-opening polymerization of morpholine-2,5-dione derivatives using organic Sn and enzyme lipase is discussed. The dependence of the macroscopic properties of the block copolymers on their structure is also presented. Bioresorbable polymers based on polydepsipeptides could be used as biomaterials in drug controlled release, tissue engineering scaffolding and shape-memory materials.

  19. Effect of gamma ray on poly(lactic acid)/poly(vinyl acetate-co-vinyl alcohol) blends as biodegradable food packaging films

    NASA Astrophysics Data System (ADS)

    Razavi, Seyed Mohammad; Dadbin, Susan; Frounchi, Masoud

    2014-03-01

    Poly(lactic acid) (PLA)/poly(vinyl acetate-co-vinyl alcohol) [P(VAc-co-VA)] blends as new transparent film packaging materials were prepared at various blend compositions and different vinyl alcohol contents. The blends and pure PLA were irradiated by gamma rays to investigate the extent of changes in the packaging material during gamma ray sterilization process. The miscibility of the blends was dependent on the blend composition and vinyl alcohol content; gamma irradiation had little effect on the extent of miscibility. The glass transition temperature of pure PLA and PLA/P(VAc-co-VA) miscible blends reduced after irradiation. On the other hand in PLA/P(VAc-co-VA) immiscible blends, while the glass transition temperature of the PLA phase decreased; that of the copolymer phase slightly increased. The reduction in the glass transition was about 10 percent for samples irradiated with 50 kGy indicating dominance of chain scission of PLA molecules at high irradiation dose. The latter was verified by drop in mechanical properties of pure PLA after exposing to gamma irradiation at 50 kGy. Blending of PLA with the copolymer P(VAc-co-VA) compensated greatly the adverse effects of irradiation on PLA. The oxygen-barrier property of the blend was superior to the neat PLA and remained almost intact with irradiation. The un-irradiated and irradiated blends had excellent transparency. Gamma ray doses used for sterilization purposes are usually less than 20 kGy. It was shown that gamma irradiation at 20 kGy had no or little adverse effects on PLA/P(VAc-co-VA) blends mechanical and gas barrier properties.

  20. Aerobic biodegradation of selected monoterpenes.

    PubMed

    Misra, G; Pavlostathis, S G; Perdue, E M; Araujo, R

    1996-07-01

    Batch experiments were conducted to assess the biotransformation potential of four hydrocarbon monoterpenes (d-limonene, alpha-pinene, gamma-terpinene, and terpinolene) and four alcohols (arbanol, linalool, plinol, and alpha-terpineol) under aerobic conditions at 23 degrees C. Both forest-soil extract and enriched cultures were used as inocula for the biodegradation experiments conducted first without, then with prior microbial acclimation to the monoterpenes tested. All four hydrocarbons and two alcohols were readily degraded. The increase in biomass and headspace CO2 concentrations paralleled the depletion of monoterpenes, thus confirming that terpene disappearance was the result of biodegradation accompanied by microbial growth and mineralization. Plinol resisted degradation in assays using inocula from diverse sources, while arbanol degraded very slowly. A significant fraction of d-limonene-derived carbon was accounted for as non-extractable, dissolved organic carbon, whereas terpineol exhibited a much higher degree of utilization. The rate and extent of monoterpene biodegradation were not significantly affected by the presence of dissolved natural organic matter.

  1. Biodegradable thermogels.

    PubMed

    Park, Min Hee; Joo, Min Kyung; Choi, Bo Gyu; Jeong, Byeongmoon

    2012-03-20

    All living creatures respond to external stimuli. Similarly, some polymers undergo conformational changes in response to changes in temperature, pH, magnetic field, electrical field, or the wavelength of light. In one type of stimuli-responsive polymer, thermogel polymers, the polymer aqueous solution undergoes sol-to-gel transition as the temperature increases. Drugs or cells can be mixed into the polymer aqueous solution when it is in its lower viscosity solution state. After injection of the solution into a target site, heating prompts the formation of a hydrogel depot in situ, which can then act as a drug releasing system or a cell growing matrix. In this Account, we describe key materials developed in our laboratory for the construction of biodegradable thermogels. We particularly emphasize recently developed polypeptide-based materials where the secondary structure and nanoassembly play an important role in the determining the material properties. This Account will provide insights for controlling parameters, such as the sol-gel transition temperature, gel modulus, critical gel concentration, and degradability of the polymer, when designing a new thermogel system for a specific biomedical application. By varying the stereochemistry of amino acids in polypeptides, the molecular weight of hydrophobic/hydrophilic blocks, the composition of the polypeptides, the hydrophobic end-capping of the polypeptides, and the microsequences of a block copolymer, we have controlled the thermosensitivity and nanoassembly patterns of the polymers. We have investigated a series of thermogel biodegradable polymers. Polymers such as poly(lactic acid-co-glycolic acid), polycaprolactone, poly(trimethylene carbonate), polycyanoacrylate, sebacic ester, polypeptide were used as hydrophobic blocks, and poly(ethylene glycol) and poly(vinyl pyrrolidone) were used as hydrophilic blocks. To prepare a polymer sensitive to pH and temperature, carboxylic acid or amine groups were introduced

  2. Preparation and crystallization kinetics of new structurally well-defined star-shaped biodegradable poly(L-lactide)s initiated with diverse natural sugar alcohols.

    PubMed

    Hao, Qinghui; Li, Faxue; Li, Qiaobo; Li, Yang; Jia, Lin; Yang, Jing; Fang, Qiang; Cao, Amin

    2005-01-01

    This study presents syntheses, structural characterization, and crystallization kinetic investigation of new structurally well-defined star-shaped poly(l-lactide)s (PLLAs). First, a series of new 3- to 6-arm star-shaped PLLAs were synthesized through SnOct(2) catalyzed ring-opening polymerization of (l)-lactide with natural sugar alcohols of glycerol, erythritol, xylitol, and sorbitol as the favorable initiators. Subsequently, their chemical structures were characterized by means of GPC, NMR, and viscometer with respect to the star-shaped structures, demonstrating the well-defined arm structures as evidenced on the g(1/2)/g' values, where g and g' denote the ratios of mean-square radius of gyration and intrinsic viscosity of a star-shaped polymer to those of a linear structural reference with similar absolute molecular weight. Furthermore, spherulite morphologies and growth rates were studied by a polarized microscopy (POM) for the synthesized star-shaped PLLAs with different molecular weights, and it was found that the more arms of a star-shaped PLLA finally resulted in a lower spherulite growth rate. With regard to the crystallization kinetics of these star-shaped PLLAs, isothermal and nonisothermal crystallization were examined by differential scanning calorimeter (DSC). It was found that Avrami exponent n values of isothermal crystallization were almost independent of the isothermal crystallization temperature T(c) for different series of star-shaped PLLAs. In contrast, the values of Avrami exponent n were observed to strongly depend on the star-shaped structures with different arms, implying their distinct nucleation mechanisms, and the more arms of a star-shaped PLLA led to a slower isothermal crystallization rate. On the basis of a modified Avrami equation, new light was shed on the nonisothermal crystallization kinetics for the star-shaped PLLAs, and the activation energies were found to vary from 146.86 kJ/mol for the linear PLLA EG-3 to 221.23 kJ/mol of

  3. Cool excimer laser-assisted angioplasty (CELA) and tibial balloon angioplasty (TBA) in management of infragenicular arterial occlusion in critical lower limb ischemia (CLI).

    PubMed

    Sultan, Sherif; Tawfick, Wael; Hynes, Niamh

    2013-04-01

    We aim to compare cool excimer laser-assisted angioplasty (CELA) versus tibial balloon angioplasty (TBA) in patients with critical limb ischemia (CLI) with tibial artery occlusive disease. The primary end point is sustained clinical improvement (SCI) and amputation-free survival (AFS). The secondary end points are binary restenosis, target extremity revascularization (TER), and cost-effectiveness. From June 2005 to October 2010, 1506 patients were referred with peripheral vascular disease and 572 with CLI. A total of 80 patients underwent 89 endovascular revascularizations (EVRs) for tibial occlusions, 47 using TBA and 42 using CELA. All patients were Rutherford category 4 to 6. Three-year SCI was enhanced with CELA (81%) compared to TBA (63.8%; P = .013). Three-year AFS significantly improved with CELA (95.2%) versus TBA (89.4%; P = .0165). Three-year freedom from TER was significantly improved with CELA (92.9%) versus 78.7% TBA (P = .026). Three-year freedom from MACE was comparable in both the groups (P = .455). Patients with CELA had significantly improved quality time without symptoms of disease or toxicity of treatment (Q-TWiST) at 3 years (10.5 months; P = .048) with incremental cost of €2073.19 per quality-adjusted life year gained. Tibial EVR provides exceptional outcome in CLI. The CELA has superior SCI, AFS, and freedom from TER, with improved Q-TWiST and cost-effectiveness.

  4. Biodegradable synthetic bone composites

    SciTech Connect

    Liu, Gao; Zhao, Dacheng; Saiz, Eduardo; Tomsia, Antoni P.

    2013-01-01

    The invention provides for a biodegradable synthetic bone composition comprising a biodegradable hydrogel polymer scaffold comprising a plurality of hydrolytically unstable linkages, and an inorganic component; such as a biodegradable poly(hydroxyethylmethacrylate)/hydroxyapatite (pHEMA/HA) hydrogel composite possessing mineral content approximately that of human bone.

  5. Fate of free and linear alcohol-ethoxylate-derived fatty alcohols in activated sludge.

    PubMed

    Federle, Thomas W; Itrich, Nina R

    2006-05-01

    Pure homologues of [1-14C] C12, C14, and C16 alcohols and the linear alcohol ethoxylates, AE [1-14C alkyl] C13E9 and C16E9 were tested in a batch-activated sludge die-away system to assess their biodegradation kinetics and to predict levels of free alcohol derived from AE biodegradation in treated effluent. First-order rates for primary biodegradation were similar for all alcohols (86-113 h(-1)) and were used to predict removal under typical treatment conditions. Predicted removals of fatty alcohols ranged from 99.76% to 99.85%, consistent with published field data. During the biodegradation of the AE homologues, lower than expected levels of fatty alcohol based upon the assumption that biodegradation occurs through central fission were observed. Rather than fatty alcohols, the major metabolites were polar materials resulting from omega oxidation of the alkyl chain prior to or concurrent with central cleavage. The amounts of free fatty alcohols that were formed from AEs in influent and escape into effluent were negligible due both to their rapid degradation and to the finding that formation of free alcohol through central cleavage is only a minor degradation pathway in activated sludge.

  6. Nonmonotonic Hydration Behavior of Bovine Serum Albumin in Alcohol/Water Binary Mixtures: A Terahertz Spectroscopic Investigation.

    PubMed

    Das, Dipak Kumar; Das Mahanta, Debasish; Mitra, Rajib Kumar

    2017-03-01

    We report the experimental observation of nonmonotonic changes in the collective hydration of bovine serum albumin (BSA) in the presence of alcohols of varying carbon-chain lengths, that is, ethanol, 2-propanol, and tert-butyl alcohol (TBA), by using terahertz (THz) time domain spectroscopy. We measured the THz absorption coefficient (α) of the protein solutions, and it was observed that α fluctuated periodically as a function of alcohol concentration at a fixed protein concentration. For a fixed alcohol concentration, an increase in the protein concentration resulted in nonmonotonic changes in α; thus, it first decreased rapidly and then increased, which was followed by a shallow decrease. An alcohol-induced α helix to random coil transition of the protein secondary structure was revealed by circular dichroism spectroscopy measurements, and the effect was most prominent in TBA. The anomalous change in the hydration was found to be a delicate balance between the various interactions present in the three-component system.

  7. Biobased and biodegradable polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Qiu, Kaiyan

    In this dissertation, various noncrosslinked and crosslinked biobased and biodegradable polymer nanocomposites were fabricated and characterized. The properties of these polymer nanocomposites, and their relating mechanisms and corresponding applications were studied and discussed in depth. Chapter 1 introduces the research background and objectives of the current research. Chapter 2 presents the development of a novel low cost carbon source for bacterial cellulose (BC) production and fabrication and characterization of biobased polymer nanocomposites using produced BC and soy protein based resins. The carbon source, soy flour extract (SFE), was obtained from defatted soy flour (SF) and BC yield achieved using SFE medium was high. The results of this study showed that SFE consists of five sugars and Acetobacter xylinum metabolized sugars in a specific order. Chapter 3 discusses the fabrication and characterization of biodegradable polymer nanocomposites using BC and polyvinyl alcohol (PVA). These polymer nanocomposites had excellent tensile and thermal properties. Crosslinking of PVA using glutaraldehyde (GA) not only increased the mechanical and thermal properties but the water-resistance. Chapter 4 describes the development and characterization of microfibrillated cellulose (MFC) based biodegradable polymer nanocomposites by blending MFC suspension with PVA. Chemical crosslinking of the polymer nanocomposites was carried out using glyoxal to increase the mechanical and thermal properties as well as to make the PVA partially water-insoluble. Chapter 5 reports the development and characterization of halloysite nanotube (HNT) reinforced biodegradable polymer nanocomposites utilizing HNT dispersion and PVA. Several separation techniques were used to obtain individualized HNT dispersion. The results indicated uniform dispersion of HNTs in both PVA and malonic acid (MA) crosslinked PVA resulted in excellent mechanical and thermal properties of the materials, especially

  8. Towards biodegradable wireless implants.

    PubMed

    Boutry, Clémentine M; Chandrahalim, Hengky; Streit, Patrick; Schinhammer, Michael; Hänzi, Anja C; Hierold, Christofer

    2012-05-28

    A new generation of partially or even fully biodegradable implants is emerging. The idea of using temporary devices is to avoid a second surgery to remove the implant after its period of use, thereby improving considerably the patient's comfort and safety. This paper provides a state-of-the-art overview and an experimental section that describes the key technological challenges for making biodegradable devices. The general considerations for the design and synthesis of biodegradable components are illustrated with radiofrequency-driven resistor-inductor-capacitor (RLC) resonators made of biodegradable metals (Mg, Mg alloy, Fe, Fe alloys) and biodegradable conductive polymer composites (polycaprolactone-polypyrrole, polylactide-polypyrrole). Two concepts for partially/fully biodegradable wireless implants are discussed, the ultimate goal being to obtain a fully biodegradable sensor for in vivo sensing.

  9. [Biodegradation of polyethylene].

    PubMed

    Yang, Jun; Song, Yi-ling; Qin, Xiao-yan

    2007-05-01

    Plastic material is one of the most serious solid wastes pollution. More than 40 million tons of plastics produced each year are discarded into environment. Plastics accumulated in the environment is highly resistant to biodegradation and not be able to take part in substance recycle. To increase the biodegradation efficiency of plastics by different means is the main research direction. This article reviewed the recent research works of polyethylene biodegradation that included the modification and pretreatment of polyethylene, biodegradation pathway, the relevant microbes and enzymes and the changes of physical, chemical and biological properties after biodegradation. The study directions of exploiting the kinds of life-forms of biodegradation polyethylene except the microorganisms, isolating and cloning the key enzymes and gene that could produce active groups, and enhancing the study on polyethylene biodegradation without additive were proposed.

  10. Hydrophobic Hydration in Water-tert-Butyl Alcohol Solutions by Extended Depolarized Light Scattering.

    PubMed

    Comez, L; Paolantoni, M; Lupi, L; Sassi, P; Corezzi, S; Morresi, A; Fioretto, D

    2015-07-23

    Molecular dynamics and structural properties of water-tert-butyl alcohol (TBA) mixtures are studied as a function of concentration by extended depolarized light scattering (EDLS) experiments. The wide frequency range, going from fraction to several thousand GHz, explored by EDLS allows distinguishing TBA rotational dynamics from structural relaxation of water and intermolecular vibrational and librational modes of the solution. Contributions to the water relaxation originating from two distinct populations, i.e. hydration and bulk water, are clearly identified. The dynamic retardation factor of hydration water with respect to the bulk, ξ ≈ 4, almost concentration independent, is one of the smallest found by EDLS among a variety of systems of different nature and complexity. This result, together with the small number of water molecules perturbed by the presence of TBA, supports the idea that hydrophobic simple molecules are less effective than hydrophilic and more complex molecules in perturbing the H-bond network of liquid water. At increasing TBA concentrations the average number of perturbed water molecules shows a pronounced decrease and the characteristic frequency of librational motions reduces significantly, both of which are results consistent with the occurrence of self-aggregation of TBA molecules.

  11. Physiologically based pharmacokinetic model for ethyl tertiary-butyl ether and tertiary-butyl alcohol in rats: Contribution of binding to α2u-globulin in male rats and high-exposure nonlinear kinetics to toxicity and cancer outcomes.

    PubMed

    Borghoff, Susan J; Ring, Caroline; Banton, Marcy I; Leavens, Teresa L

    2017-05-01

    In cancer bioassays, inhalation, but not drinking water exposure to ethyl tertiary-butyl ether (ETBE), caused liver tumors in male rats, while tertiary-butyl alcohol (TBA), an ETBE metabolite, caused kidney tumors in male rats following exposure via drinking water. To understand the contribution of ETBE and TBA kinetics under varying exposure scenarios to these tumor responses, a physiologically based pharmacokinetic model was developed based on a previously published model for methyl tertiary-butyl ether, a structurally similar chemical, and verified against the literature and study report data. The model included ETBE and TBA binding to the male rat-specific protein α2u-globulin, which plays a role in the ETBE and TBA kidney response observed in male rats. Metabolism of ETBE and TBA was described as a single, saturable pathway in the liver. The model predicted similar kidney AUC0-∞ for TBA for various exposure scenarios from ETBE and TBA cancer bioassays, supporting a male-rat-specific mode of action for TBA-induced kidney tumors. The model also predicted nonlinear kinetics at ETBE inhalation exposure concentrations above ~2000 ppm, based on blood AUC0-∞ for ETBE and TBA. The shift from linear to nonlinear kinetics at exposure concentrations below the concentration associated with liver tumors in rats (5000 ppm) suggests the mode of action for liver tumors operates under nonlinear kinetics following chronic exposure and is not relevant for assessing human risk. Copyright © 2016 The Authors Journal of Applied Toxicology Published by John Wiley & Sons Ltd.

  12. Characterization of biodegraded coals

    SciTech Connect

    Bean, R.M.; Franz, J.A.; Campbell, J.C.; Linehan, J.C.; Stewart, D.L.; Thomas, B.L.

    1988-04-01

    We have been able to accomplish the biodegradation of bituminous Illinois No. 6 coal after a pretreatment consisting of air oxidation, using a culture of the fungus Penicillium sp. We report in this paper results of chemical and spectrometric analyses of the starting materials and products from Illinois No. 6 coal biodegradation, and compare the results with those previously reported from the biodegradation of leonardite. 13 refs., 1 fig., 5 tabs.

  13. Biodegradability of Plastics

    PubMed Central

    Tokiwa, Yutaka; Calabia, Buenaventurada P.; Ugwu, Charles U.; Aiba, Seiichi

    2009-01-01

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed. PMID:19865515

  14. Biodegradability of plastics.

    PubMed

    Tokiwa, Yutaka; Calabia, Buenaventurada P; Ugwu, Charles U; Aiba, Seiichi

    2009-08-26

    Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.). In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  15. Biodegradation of plastics.

    PubMed

    Shimao, M

    2001-06-01

    Widespread studies on the biodegradation of plastics have been carried out in order to overcome the environmental problems associated with synthetic plastic waste. Recent work has included studies of the distribution of synthetic polymer-degrading microorganisms in the environment, the isolation of new microorganisms for biodegradation, the discovery of new degradation enzymes, and the cloning of genes for synthetic polymer-degrading enzymes.

  16. Alcoholism, Alcohol, and Drugs

    ERIC Educational Resources Information Center

    Rubin, Emanuel; Lieber, Charles S.

    1971-01-01

    Describes research on synergistic effects of alcohol and other drugs, particularly barbiturates. Proposes biochemical mechanisms to explain alcoholics' tolerance of other drugs when sober, and increased sensitivity when drunk. (AL)

  17. Aerobic Biodegradation of Fuel Oxygenates

    DTIC Science & Technology

    2007-06-01

    microbial attack. MTBE is a colorless flammable liquid with a distinct taste and odor (ATSDR, 1997). MTBE’s very low taste and odor threshold, at...based oxygenates chemical structure is characterized by the addition of a hydroxyl (O-H) group bonded to an alkyl group. This removal of a hydrogen and...OSHA, 1996). Once TBA reaches its melting point of 25.6o C (78.1o F) it forms a flammable, volatile, clear liquid . The presence of TBA in many

  18. HIGH LEVELS OF MONOAROMATIC COMPOUNDS LIMIT THE USE OF SOLID-PHASE MICROEXTRACTION OF METHYL TERTIARY BUTYL ETHER AND TERTIARY BUTYL ALCOHOL

    EPA Science Inventory

    Recently, two papers reported the use of solid-phase microextraction (SPME) with polydimethylsiloxane(PDMS)/Carboxen fibers to determine trace levels of methyl tertiary butyl ether (MTBE) and tertiary butyl alcohol (tBA) in water. Attempts were made to apply this technique to th...

  19. Grey water biodegradability.

    PubMed

    Ghunmi, Lina Abu; Zeeman, Grietje; Fayyad, Manar; van Lier, Jules B

    2011-02-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different conditions in the biodegradation test. The maximum aerobic and anaerobic biodegradability and conversion rate for the different COD fractions is determined. The results show that, on average, dormitory grey water COD fractions are 28% suspended, 32% colloidal and 40% dissolved. The studied factors incubation time, inoculum addition and temperature are influencing the determined biodegradability. The maximum biodegradability and biodegradation rate differ between different COD fractions, viz. COD(ss), COD(col) and COD(diss). The dissolved COD fraction is characterised by the lowest degradation rate, both for anaerobic and aerobic conditions. The maximum biodegradability for aerobic and anaerobic conditions is 86 and 70% respectively, whereas the first order conversion rate constant, k₂₀, is 0.119 and 0.005 day⁻¹, respectively. The anaerobic and aerobic conversion rates in relation to temperature can be described by the Arrhenius relation, with temperature coefficients of 1.069 and 1.099, respectively.

  20. Biodegradation of the gasoline oxygenates methyl tert-butyl ether, ethyl tert-butyl ether, and tert-amyl methyl ether by propane-oxidizing bacteria.

    PubMed

    Steffan, R J; McClay, K; Vainberg, S; Condee, C W; Zhang, D

    1997-11-01

    Several propane-oxidizing bacteria were tested for their ability to degrade gasoline oxygenates, including methyl tert-butyl ether (MTBE), ethyl tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). Both a laboratory strain and natural isolates were able to degrade each compound after growth on propane. When propane-grown strain ENV425 was incubated with 20 mg of uniformly labeled [14C]MTBE per liter, the strain converted > 60% of the added MTBE to 14CO2 in < 30 h. The initial oxidation of MTBE and ETBE resulted in the production of nearly stoichiometric amounts of tert-butyl alcohol (TBA), while the initial oxidation of TAME resulted in the production of tert-amyl alcohol. The methoxy methyl group of MTBE was oxidized to formaldehyde and ultimately to CO2. TBA was further oxidized to 2-methyl-2-hydroxy-1-propanol and then 2-hydroxy isobutyric acid; however, neither of these degradation products was an effective growth substrate for the propane oxidizers. Analysis of cell extracts of ENV425 and experiments with enzyme inhibitors implicated a soluble P-450 enzyme in the oxidation of both MTBE and TBA. MTBE was oxidized to TBA by camphor-grown Pseudomonas putida CAM, which produces the well-characterized P-450cam, but not by Rhodococcus rhodochrous 116, which produces two P-450 enzymes. Rates of MTBE degradation by propane-oxidizing strains ranged from 3.9 to 9.2 nmol/min/mg of cell protein at 28 degrees C, whereas TBA was oxidized at a rate of only 1.8 to 2.4 nmol/min/mg of cell protein at the same temperature.

  1. Characterization of biodegraded coals

    SciTech Connect

    Bean, R.M.; Franz, J.A.; Campbell, J.A.; Linehan, J.C.; Stewart, D.L.; Thomas, B.L.

    1988-01-01

    Microbial degradation of coals to materials that are soluble in water has been a topic of intensive research for the last few years. The potential for economical recovery of low-grade coals, coupled with possibilities for further upgrading by microbial desulfurization or methanation has spurred intensive research at a number of laboratories. Until very recently, coal biodegradation has been accomplished using low-grade, naturally oxidized coals such as leonardiate, or coals subjected to pretreatment with oxidizing chemicals. The authors have been able to accomplish the biodegradation of bituminous Illinois 6 coal after a pretreatment consisting of air oxidation, using a culture of the fungus Penicillium sp. They report in this paper results of chemical and spectrometric analyses of the starting materials and products from Illinois 6 coal biodegradation, and compare the results with those previously reported from the biodegradation of leonardite.

  2. Alcohol Alert

    MedlinePlus

    ... Us You are here Home » Alcohol Alert Alcohol Alert The NIAAA Alcohol Alert is a quarterly bulletin that disseminates important research ... text. To order single copies of select Alcohol Alerts, see ordering Information . To view publications in PDF ...

  3. Alcoholic neuropathy

    MedlinePlus

    Neuropathy - alcoholic; Alcoholic polyneuropathy ... The exact cause of alcoholic neuropathy is unknown. It likely includes both a direct poisoning of the nerve by the alcohol and the effect of poor nutrition ...

  4. Alcoholism - resources

    MedlinePlus

    Resources - alcoholism ... The following organizations are good resources for information on alcoholism : Alcoholics Anonymous -- www.aa.org Al-Anon Family Groups www.al-anon.org National Institute on Alcohol ...

  5. Alcohol Alert: Genetics of Alcoholism

    MedlinePlus

    ... 84 Alcohol Alert Number 84 Print Version The Genetics of Alcoholism Why can some people have a ... to an increased risk of alcoholism. Cutting-Edge Genetic Research in Alcoholism Although researchers already have made ...

  6. Molecularly Imprinted Biodegradable Nanoparticles

    PubMed Central

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-01

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization. PMID:28071745

  7. Molecularly Imprinted Biodegradable Nanoparticles

    NASA Astrophysics Data System (ADS)

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-01

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization.

  8. Molecularly Imprinted Biodegradable Nanoparticles.

    PubMed

    Gagliardi, Mariacristina; Bertero, Alice; Bifone, Angelo

    2017-01-10

    Biodegradable polymer nanoparticles are promising carriers for targeted drug delivery in nanomedicine applications. Molecu- lar imprinting is a potential strategy to target polymer nanoparticles through binding of endogenous ligands that may promote recognition and active transport into specific cells and tissues. However, the lock-and-key mechanism of molecular imprinting requires relatively rigid cross-linked structures, unlike those of many biodegradable polymers. To date, no fully biodegradable molecularly imprinted particles have been reported in the literature. This paper reports the synthesis of a novel molecularly- imprinted nanocarrier, based on poly(lactide-co-glycolide) (PLGA) and acrylic acid, that combines biodegradability and molec- ular recognition properties. A novel three-arm biodegradable cross-linker was synthesized by ring-opening polymerization of glycolide and lactide initiated by glycerol. The resulting macromer was functionalized by introduction of end-functions through reaction with acryloyl chloride. Macromer and acrylic acid were used for the synthesis of narrowly-dispersed nanoparticles by radical polymerization in diluted conditions in the presence of biotin as template molecule. The binding capacity of the imprinted nanoparticles towards biotin and biotinylated bovine serum albumin was twentyfold that of non-imprinted nanoparti- cles. Degradation rates and functional performances were assessed in in vitro tests and cell cultures, demonstrating effective biotin-mediated cell internalization.

  9. The influence of structural components of alkyl esters on their anaerobic biodegradation in marine sediment.

    PubMed

    Herman, David; Roberts, Deborah

    2006-10-01

    Ester-based organic compounds are one type of synthetic base fluid added to drilling mud used during off-shore oil-drilling operations in the Gulf of Mexico. Concern over the environmental impact of synthetic base fluid (SBF) contaminated rock cuttings discharged into the Gulf of Mexico has prompted the promulgation of EPA regulations requiring that all SBF be tested for biodegradability in marine sediment prior to their use in the Gulf. In order to allow the design or selection of suitably biodegradable esters, the anaerobic biodegradability of a variety of ester compounds was tested using a marine sediment inoculum to reveal the effect of: (a) increasing the chain length of the acid moiety, (b) increasing the chain length of the alcohol moiety; (c) alternating the relative size of the alcohol and acid moieties, (d) branching in the alcohol moiety, and (e) the presence of an unsaturated bond in the acidic moiety. The chemical structure of esters was found to affect the completeness and rate of anaerobic biodegradation, and would affect their ability to be certified for use as an SBF in the Gulf of Mexico. Recommendations for ester usage include using esters that have a total carbon number of between 12 and 18 and avoiding the use of branched alcohols (or acids by inference). The presence of an unsaturated bond in the acid (or alcohol by inference) increased biodegradability of the ester.

  10. Directions for environmentally biodegradable polymer research

    SciTech Connect

    Swift, G. )

    1993-03-01

    A major factor promoting interest in biodegradable polymers is the growing concern raised by the recalcitrance and unknown environmental fate of many of the currently used synthetic polymers. These polymers include both water-soluble and water-insoluble types. The former are generally specialty polymers with functional groups that effect water solubility such as carboxyl, hydroxyl, amido, etc.; the latter are usually nonfunctional polymers commonly referred to as commodity plastics. Both types of polymers are widely used in many applications. Water-soluble polymers are used, for example, in cosmetics, water treatment, dispersants, thickeners, detergents, and superabsorbents, and they include poly(acrylic acid), polyacrylamide, poly(vinyl alcohol), and poly(ethylene glycol). Plastics are used in packaging, disposable diaper backing, fishing nets, and agricultural film; they include polymers such as polyethylene, polypropylene, polystyrene, poly(vinyl chloride), poly(ethylene terephthalate), and Nylon 6.6. In this Account, the author presents a personal perspective on definitions and test protocols for biodegradable polymers as well as how they will influence the future direction and developments in the field. However, before doing so he digresses briefly to present a commentary on the role of biodegradable polymers in environmental waste management. This should be useful for those readers unfamiliar with the subject, and it will set the stage for the rest of the discussion. 36 refs., 3 figs.

  11. Editorial: Biodegradable Materials

    PubMed Central

    Schaschke, Carl; Audic, Jean-Luc

    2014-01-01

    This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment. PMID:25421242

  12. Characterization and aerobic biodegradation of selected monoterpenes

    SciTech Connect

    Misra, G.; Pavlostathis, S.G.; Li, J.; Purdue, E.M.

    1996-12-31

    Monoterpenes are biogenic chemicals and occur in abundance in nature. Large-scale industrial use of these chemicals has recently been initiated in an attempt to replace halogenated solvents and chlorofluorocarbons which have been implicated in the stratospheric depletion of ozone. This study examined four hydrocarbon monoterpenes (d-limonene, {alpha}-pinene, {gamma}-terpinene, and terpinolene) and four alcohols (arbanol, linalool, plinol, and {alpha}-terpineol). Water solubility, vapor pressure, and octanol/water partition coefficients were estimated. Aerobic biodegradability tests were conducted in batch reactors by utilizing forest soil extract and enriched cultures as inoculum. The hydrophobic nature and high volatility of the hydrocarbons restricted the investigation to relatively low aqueous concentrations. Each monoterpene was analyzed with a gas chromatograph equipped with a flame ionization detector after extraction from the aqueous phase with isooctane. Terpene mineralization was tested by monitoring liquid-phase carbon, CO{sub 2} production and biomass growth. All four hydrocarbons and two alcohols readily degraded under aerobic conditions. Plinol resisted degradation in assays using inocula from diverse sources, while arbanol degraded very slowly. The intrinsic biokinetics coefficients for the degradation of d-limonene and {alpha}-terpineol were estimated by using cultures enriched with the respective monoterpenes. Monoterpene biodegradation followed Monod kinetics.

  13. Systemic approaches to biodegradation.

    PubMed

    Trigo, Almudena; Valencia, Alfonso; Cases, Ildefonso

    2009-01-01

    Biodegradation, the ability of microorganisms to remove complex chemicals from the environment, is a multifaceted process in which many biotic and abiotic factors are implicated. The recent accumulation of knowledge about the biochemistry and genetics of the biodegradation process, and its categorization and formalization in structured databases, has recently opened the door to systems biology approaches, where the interactions of the involved parts are the main subject of study, and the system is analysed as a whole. The global analysis of the biodegradation metabolic network is beginning to produce knowledge about its structure, behaviour and evolution, such as its free-scale structure or its intrinsic robustness. Moreover, these approaches are also developing into useful tools such as predictors for compounds' degradability or the assisted design of artificial pathways. However, it is the environmental application of high-throughput technologies from the genomics, metagenomics, proteomics and metabolomics that harbours the most promising opportunities to understand the biodegradation process, and at the same time poses tremendous challenges from the data management and data mining point of view.

  14. Compared in vivo toxicity in mice of lung delivered biodegradable and non-biodegradable nanoparticles.

    PubMed

    Aragao-Santiago, Letícia; Hillaireau, Hervé; Grabowski, Nadège; Mura, Simona; Nascimento, Thais L; Dufort, Sandrine; Coll, Jean-Luc; Tsapis, Nicolas; Fattal, Elias

    2016-01-01

    To design nanoparticle (NP)-based drug delivery systems for pulmonary administration, biodegradable materials are considered safe, but their potential toxicity is poorly explored. We here explore the lung toxicity in mice of biodegradable nanoparticles (NPs) and compare it to the toxicity of non-biodegradable ones. NP formulations of poly(d,l-lactide-co-glycolide) (PLGA) coated with chitosan (CS), poloxamer 188 (PF68) or poly(vinyl alcohol) (PVA), which renders 200 nm NPs of positive, negative or neutral surface charge respectively, were analyzed for their biodistribution by in vivo fluorescence imaging and their inflammatory potential after single lung nebulization in mice. After exposure, analysis of bronchoalveolar lavage (BAL) cell population, protein secretion and cytokine release as well as lung histology were carried out. The inflammatory response was compared to the one induced by non-biodegradable counterparts, namely, TiO2 of rutile and anatase crystal form and polystyrene (PS). PLGA NPs were mostly present in mice lungs, with little passage to other organs. An increase in neutrophil recruitment was observed in mice exposed to PS NPs 24 h after nebulization, which declined at 48 h. This result was supported by an increase in interleukin (IL)-6 and tumor necrosis factor α (TNFα) in BAL supernatant at 24 h. TiO2 anatase NPs were still present in lung cells 48 h after nebulization and induced the expression of pro-inflammatory cytokines and the recruitment of polymorphonuclear cells to BAL. In contrast, regardless of their surface charge, PLGA NPs did not induce significant changes in the inflammation markers analyzed. In conclusion, these results point out to a safe use of PLGA NPs regardless of their surface coating compared to non-biodegradable ones.

  15. Biodegradability of poly(3-hydroxybutyrate) film grafted with vinyl acetate: Effect of grafting and saponification

    NASA Astrophysics Data System (ADS)

    Wada, Yuki; Seko, Noriaki; Nagasawa, Naotsugu; Tamada, Masao; Kasuya, Ken-ichi; Mitomo, Hiroshi

    2007-06-01

    Radiation-induced graft polymerization of vinyl acetate (VAc) onto poly(3-hydroxybutyrate) (PHB) film was carried out. At a degree of grafting higher than 5%, the grafted films (PHB-g-VAc) completely lost the enzymatic degradability that is characteristic of PHB due to the grafted VAc covering the surface of the PHB film. However, the biodegradability of the PHB-g-VAc films was recovered when the films were saponified in alkali solution under optimum conditions. Graft chains of the PHB-g-VAc film reacted selectively to become biodegradable polyvinyl alcohol (PVA). The biodegradability of the saponified PHB-g-VAc film increased rapidly with time.

  16. Biodegradation of Cyanuric Acid

    PubMed Central

    Saldick, Jerome

    1974-01-01

    Cyanuric acid biodegrades readily under a wide variety of natural conditions, and particularly well in systems of either low or zero dissolved-oxygen level, such as anaerobic activated sludge and sewage, soils, muds, and muddy streams and river waters, as well as ordinary aerated activated sludge systems with typically low (1 to 3 ppm) dissolved-oxygen levels. Degradation also proceeds in 3.5% sodium chloride solution. Consequently, there are degradation pathways widely available for breaking down cyanuric acid discharged in domestic effluents. The overall degradation reaction is merely a hydrolysis; CO2 and ammonia are the initial hydrolytic breakdown products. Since no net oxidation occurs during this breakdown, biodegradation of cyanuric acid exerts no primary biological oxygen demand. However, eventual nitrification of the ammonia released will exert its usual biological oxygen demand. PMID:4451360

  17. Safe biodegradable fluorescent particles

    DOEpatents

    Martin, Sue I.; Fergenson, David P.; Srivastava, Abneesh; Bogan, Michael J.; Riot, Vincent J.; Frank, Matthias

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  18. Evaluation of the effects of nanoscale zero-valent iron (nZVI) dispersants on intrinsic biodegradation of trichloroethylene (TCE).

    PubMed

    Chang, Y C; Huang, S C; Chen, K F

    2014-01-01

    In this study, the biodegradability of nanoscale zero-valent iron (nZVI) dispersants and their effects on the intrinsic biodegradation of trichloroethylene (TCE) were evaluated. Results of a microcosm study show that the biodegradability of three dispersants followed the sequence of: polyvinyl alcohol-co-vinyl acetate-co-itaconic acid (PV3A) > polyoxyethylene (20) sorbitan monolaurate (Tween 20) > polyacrylic acid (PAA) under aerobic conditions, and PV3A > Tween 20 > PAA under anaerobic conditions. Natural biodegradation of TCE was observed under both aerobic and anaerobic conditions. No significant effects were observed on the intrinsic biodegradation of TCE under aerobic conditions with the presence of the dispersants. The addition of PAA seemed to have a slightly adverse impact on anaerobic TCE biodegradation. Higher accumulation of the byproducts of anaerobic TCE biodegradation was detected with the addition of PV3A and Tween 20. The diversity of the microbial community was enhanced under aerobic conditions with the presence of more biodegradable PV3A and Tween 20. The results of this study indicate that it is necessary to select an appropriate dispersant for nZVI to prevent a residual of the dispersant in the subsurface. Additionally, the effects of the dispersant on TCE biodegradation and the accumulation of TCE biodegrading byproducts should also be considered.

  19. Biodegradable Polymers for the Environment

    NASA Astrophysics Data System (ADS)

    Gross, Richard A.; Kalra, Bhanu

    2002-08-01

    Biodegradable polymers are designed to degrade upon disposal by the action of living organisms. Extraordinary progress has been made in the development of practical processes and products from polymers such as starch, cellulose, and lactic acid. The need to create alternative biodegradable water-soluble polymers for down-the-drain products such as detergents and cosmetics has taken on increasing importance. Consumers have, however, thus far attached little or no added value to the property of biodegradability, forcing industry to compete head-to-head on a cost-performance basis with existing familiar products. In addition, no suitable infrastructure for the disposal of biodegradable materials exists as yet.

  20. Production of mono- and di-carboxylated polyethylene glycols as a factor obstacle to the successful ozonation-assisted biodegradation of ethoxylated compounds.

    PubMed

    Nakai, Satoshi; Okuda, Tetsuji; Nishijima, Wataru; Okada, Mitsumasa

    2015-10-01

    Ozonation is believed to improve the biodegradability of organic compounds. In the present study, degradation of nonylphenol ethoxylates (NPEOs) was monitored in hybrid treatment systems consisting of ozonation and microbial degradation processes. We found that ozonation of NPEOs decreased, rather than increased, the biodegradability under certain conditions. The timing of ozonation was a definitive factor in determining whether ozonation increased or decreased the biodegradation rates of NPEOs. Initial ozonation of NPEOs prior to biodegradation reduced the rate of dissolved organic carbon (DOC) removal during the subsequent 14 d of biodegradation, whereas intermediate ozonation at the 9th day of biodegradation improved subsequent DOC removal during 14 d of NPEO biodegradation. Furthermore, reduction of DOC removal was also observed, when initial ozonation prior to biodegradation was subjected to cetyl alcohol ethoxylates. The production of less biodegradable intermediates, such as mono- and dicarboxylated polyethylene glycols (MCPEGs and DCPEGs), was responsible for the negative effect of ozonation on biodegradability of NPEOs. DCPEGs and MCPEGs were produced by biodegradation of polyethylene glycols (PEGs) that were ozonolysis products of the NPEOs, and the biodegradability of DCPEGs and MCPEGs was less than that of the precursor PEGs. The results indicate that, if the target chemicals contain ethoxy chains, production of PEGs may be one of the important factors when ozonation is considered.

  1. Alcohol Calorie Calculator

    MedlinePlus

    ... Alcohol Calorie Calculator Weekly Total 0 Calories Alcohol Calorie Calculator Find out the number of beer and ... Calories College Alcohol Policies Interactive Body Calculators Alcohol Calorie Calculator Alcohol Cost Calculator Alcohol BAC Calculator Alcohol ...

  2. A model for simultaneous crystallisation and biodegradation of biodegradable polymers.

    PubMed

    Han, Xiaoxiao; Pan, Jingzhe

    2009-01-01

    This paper completes the model of biodegradation for biodegradable polymers that was previously developed by Wang et al. (Wang Y, Pan J, Han X, Sinka, Ding L. A phenomenological model for the degradation of biodegradable polymers. Biomaterials 2008;29:3393-401). Crystallisation during biodegradation was not considered in the previous work which is the topic of the current paper. For many commonly used biodegradable polymers, there is a strong interplay between crystallisation and hydrolysis reaction during biodegradation - the chain cleavage caused by the hydrolysis reaction provides an extra mobility for the polymer chains to crystallise and the resulting crystalline phase becomes more resistant to further hydrolysis reaction. This paper presents a complete theory to describe this interplay. The fundamental equations in the Avrami's theory for crystallisation are modified and coupled to the diffusion-reaction equations that were developed in our previous work. The mathematical equations are then applied to three biodegradable polymers for which long term degradation data are available in the literature. It is shown that the model can capture the behavior of the major biodegradable polymers very well.

  3. Preparation of hydrophilic polyhydroxyalkyl glutamine crosslinked films and its biodegradability.

    PubMed

    Pan, Shi-Rong; Wang, Qin-Mei; Yi, Wu

    2007-09-01

    Polybenzyl glutamate (PBLG) or polymethyl glutamate (PMLG) films have been aminolyzed with amino alcohol and crosslinked with aliphatic diamine at 60 degrees C for 48 h simultaneously which led to the formation of crosslinked films of polyhydroxyalkyl glutamine (PHAG). ATR-IR indicates that for the aminolysis of PBLG with 2-amino-1-ethanol or 3-amino-1-propanol, benzyl glutamate almost completely turned to hydroxyalkyl glutamine, however for the aminolysis of PMLG with 5-amino-1-pentanol, methyl glutamate partially turned to hydroxypentanyl glutamine. The water-swelling test shows that water-swelling ratio Q of PHAG films from amino alcohol with longer carbon chain was smaller, the PHAG films crosslinked by 1,2-diamino ethane have the higher water-swelling ratio Q, but the PHAG films crosslinked by 1,8-diamino octane have the lower water swelling ratio Q; and PHAG films with a greater amount of crosslinking agents have high crosslinking density or the low water swelling-ratio Q for same amino alcohol and diamine. It is obvious from in vitro enzymatic hydrolysis test that specimens with smaller swelling ratio Q displayed larger T(1/2), time for half weight digestion of PHAG film, that is, less biodegradability. Therefore, biodegradability of the crosslinked PHAG films can be controlled by changing amino alcohol and diamine.

  4. Biodegradation of cresol isomers in anoxic aquifers.

    PubMed Central

    Smolenski, W J; Suflita, J M

    1987-01-01

    The biodegradation of o-, m-, and p-cresol was examined in material obtained from a shallow anaerobic alluvial sand aquifer. The cresol isomers were preferentially metabolized, with p-cresol being the most easily degraded. m-Cresol was more persistent than the para-isomer, and o-cresol persisted for over 90 days. Biodegradation of cresol isomers was favored under sulfate-reducing conditions (SRC) compared with that under methanogenic conditions (MC). Slurries that were acclimated to p-cresol metabolism transformed this substrate at 18 and 330 nmol/h per g (dry weight) for MC and SRC, respectively. Inhibition of electron flow to sulfate reduction with 2.0 mM molybdate reduced p-cresol metabolism in incubations containing sulfate. When methanogenesis was blocked with 5 mM bromoethanesulfonic acid in incubations lacking sulfate, p-cresol catabolism was retarded. Under SRC 3.4 mol of sulfate was consumed per mol of p-cresol metabolized. The addition of sulfate to methanogenic incubations stimulated p-cresol degradation. Simultaneous adaptation studies in combination with spectrophotometric and chromatographic analysis of metabolites indicated that p-cresol was oxidized under SRC to p-hydroxybenzoate via the corresponding alcohol and aldehyde. This series of reactions was inhibited under sulfate-limited or aerobic conditions. Therefore, the primary catabolic event for p-cresol decomposition under SRC appears to involve the hydroxylation of the aryl methyl group. PMID:3579279

  5. Biodegradation of Methyl tert-Butyl Ether by Co-Metabolism with a Pseudomonas sp. Strain

    PubMed Central

    Li, Shanshan; Wang, Shan; Yan, Wei

    2016-01-01

    Co-metabolic bioremediation is supposed to be an impressive and promising approach in the elimination technology of methyl tert-butyl ether (MTBE), which was found to be a common pollutant worldwide in the ground or underground water in recent years. In this paper, bacterial strain DZ13 (which can co-metabolically degrade MTBE) was isolated and named as Pseudomonas sp. DZ13 based on the result of 16S rRNA gene sequencing analysis. Strain DZ13 could grow on n-alkanes (C5-C8), accompanied with the co-metabolic degradation of MTBE. Diverse n-alkanes with different carbon number showed a significant influence on the degradation rate of MTBE and accumulation of tert-butyl alcohol (TBA). When Pseudomonas sp. DZ13 co-metabolically degraded MTBE with n-pentane as the growth substrate, a higher MTBE-degrading rate (Vmax = 38.1 nmol/min/mgprotein, Ks = 6.8 mmol/L) and lower TBA-accumulation was observed. In the continuous degradation experiment, the removal efficiency of MTBE by Pseudomonas sp. Strain DZ13 did not show an obvious decrease after five times of continuous addition. PMID:27608032

  6. National Institute on Alcohol Abuse and Alcoholism

    MedlinePlus

    ... Alcohol Awareness Month April is Alcohol Awareness Month Biosensor Challenge Learn more College Drinking Learn More Alcohol Dependence Get the facts Alcohol Awareness Month Biosensor Challenge College Drinking Alcohol Dependence Latest News New & ...

  7. Biodegradation of crude oils.

    PubMed

    Bosecker, K; Teschner, M; Wehner, H

    1989-01-01

    Petroleum from well sites in the Gifhorn Trough (Lower Saxony, NW-Germany) and the Maracaibo Basin (Venezuela) contained various types of microorganisms capable of degrading crude oils. Genetically related oils were inoculated with the isolated microorganisms and the degradation of the oils was followed by chromatographic techniques. Parameters important for the reactions (pH, supply of oxygen, nitrogen and phosphorus, reaction medium) were monitored and optimized. The degradation of n-alkanes was followed closely. Microorganisms active in degradation (yeast, bacteria) easily survived a period of inactivity due to missing nutrients and were reactivated within hours to degrade newly added crude oil. Under substrate-limiting conditions selectivity of degradation was found, destroying medium-chain n-alkanes (C20, C21) at a faster rate than long-chain n-alkanes (C30, C31). During degradation the physical parameters of the crude oils (e.g. density, viscosity, average molecular weight) were altered and shifted into the direction of heavy oil. In vitro degraded oil is very similar to oil degraded in nature. Aromatic hydrocarbons and biomarker molecules (steranes and triterpanes) were not degraded under the conditions used. Pyrolysis-GC analysis of asphaltenes revealed no significant changes in the composition of pyrolyzates during biodegradation. There is sufficient evidence that heavy oils - besides some other effects - are generated by the in situ-biodegradation of conventional oils.

  8. Marine Oil Biodegradation

    SciTech Connect

    Hazen, Terry C.; Prince, Roger; Mahmoudi, Nagissa

    2015-12-23

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to ‘bloom’ in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine waters with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.

  9. Marine Oil Biodegradation

    DOE PAGES

    Hazen, Terry C.; Prince, Roger; Mahmoudi, Nagissa

    2015-12-23

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to ‘bloom’ in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine watersmore » with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.« less

  10. Marine Oil Biodegradation.

    PubMed

    Hazen, Terry C; Prince, Roger C; Mahmoudi, Nagissa

    2016-03-01

    Crude oil has been part of the marine environment for millions of years, and microbes that use its rich source of energy and carbon are found in seawater, sediments, and shorelines from the tropics to the polar regions. Catastrophic oil spills stimulate these organisms to "bloom" in a reproducible fashion, and although oil does not provide bioavailable nitrogen, phosphorus or iron, there are enough of these nutrients in the sea that when dispersed oil droplets dilute to low concentrations these low levels are adequate for microbial growth. Most of the hydrocarbons in dispersed oil are degraded in aerobic marine waters with a half-life of days to months. In contrast, oil that reaches shorelines is likely to be too concentrated, have lower levels of nutrients, and have a far longer residence time in the environment. Oil that becomes entrained in anaerobic sediments is also likely to have a long residence time, although it too will eventually be biodegraded. Thus, data that encompass everything from the ecosystem to the molecular level are needed for understanding the complicated process of petroleum biodegradation in marine environments.

  11. Microbial biosurfactants and biodegradation.

    PubMed

    Ward, Owen P

    2010-01-01

    Microbial biosurfactants are amphipathic molecules having typical molecular weights of 500-1500 Da, made up of peptides, saccharides or lipids or their combinations. In biodegradation processes they mediate solubilisation, mobilization and/or accession of hydrophobic substrates to microbes. They may be located on the cell surface or be secreted into the extracellular medium and they facilitate uptake of hydrophobic molecules through direct cellular contact with hydrophobic solids or droplets or through micellarisation. They are also involved in cell physiological processes such as biofilm formation and detachment, and in diverse biofilm associated processes such as wastewater treatment and microbial pathogenesis. The protection of contaminants in biosurfactants micelles may also inhibit uptake of contaminants by microbes. In bioremediation processes biosurfactants may facilitate release of contaminants from soil, but soils also tend to bind surfactants strongly which makes their role in contaminant desorption more complex. A greater understanding of the underlying roles played by biosurfactants in microbial physiology and in biodegradative processes is developing through advances in cell and molecular biology.

  12. Biodegradable Composites Based on Starch/EVOH/Glycerol Blends and Coconut Fibers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Unripe coconut fibers were used as fillers in a biodegradable polymer matrix of starch/Ethylene vinyl alcohol (EVOH)/glycerol. The effects of fiber content on the mechanical, thermal and structural properties were evaluated. The addition of coconut fiber into starch/EVOH/glycerol blends reduced the ...

  13. Ring-Opening Polymerization of Lactide to Form a Biodegradable Polymer

    ERIC Educational Resources Information Center

    Robert, Jennifer L.; Aubrecht, Katherine B.

    2008-01-01

    In this laboratory activity for introductory organic chemistry, students carry out the tin(II) bis(2-ethylhexanoate)/benzyl alcohol mediated ring-opening polymerization of lactide to form the biodegradable polymer polylactide (PLA). As the mechanism of the polymerization is analogous to that of a transesterification reaction, the experiment can be…

  14. Alcohols toxicology

    SciTech Connect

    Wimer, W.W.; Russell, J.A.; Kaplan, H.L.

    1984-01-01

    A comprehensive reference volume which summarizes literature reports of the known consequences of human and animal contact with alcohols and alcohol-derived substances is presented. Following a discussion of alcohol nomenclature and a brief history of alcohols, the authors have provided detailed chapters on the toxicology of methanol, ethanol, normal and isopropanol, and the butanols. Properties of these alcohols are compared; industrial hygiene and exposure limits are discussed. Additional sections are included covering processing and production technology and exhaust emissions studies. Of particular interest are the section containing abstracts and synopses of principal works and the extensive bibliography of studies dating from the 1800s. 331 references, 26 figures, 56 tables

  15. IRIS Toxicological Review of tert-Butyl Alcohol (tert-Butanol) ...

    EPA Pesticide Factsheets

    In August 2013, EPA released the draft literature searches and associated search strategies, evidence tables, and exposure response arrays for TBA to obtain input from stakeholders and the public prior to developing the draft IRIS assessment. Specifically, EPA was interested in comments on the following: Draft literature search strategies The approach for identifying studies The screening process for selecting pertinent studies The resulting list of pertinent studies Preliminary evidence tables The process for selecting studies to include in evidence tables The quality of the studies in the evidence tables The literature search strategy, which describes the processes for identifying scientific literature, contains the studies that EPA considered and selected to include in the evidence tables. The preliminary evidence tables and exposure-response arrays present the key study data in a standardized format. The evidence tables summarize the available critical scientific literature. The exposure-response figures provide a graphical representation of the responses at different levels of exposure for each study in the evidence table. EPA is undertaking a new health assessment for t-butyl alcohol (TBA) for the Integrated Risk Information System (IRIS). The outcome of this project will be a Toxicological Review and IRIS and IRIS Summary of TBA that will be entered on the IRIS database. IRIS is an EPA da

  16. Alcohol Use Disorders

    MedlinePlus

    ... Search Alcohol & Your Health Overview of Alcohol Consumption Alcohol's Effects on the Body Alcohol Use Disorder Fetal Alcohol ... less effect than before? Found that when the effects of alcohol were wearing off, you had withdrawal symptoms, such ...

  17. Biodegradation of propellant ingredients

    SciTech Connect

    Zhang, Y.Z.; Sundaram, S.T.; Sharma, A.

    1995-12-31

    This paper summarizes efforts to degrade nitrocellulose (NC) and nitroglycerin (NG) with fungi. Screening experiments were performed to determine the ability of mycelial fungi to biodegrade NC. The greatest amount of NC degradation was obtained with Sclerotium rolfsii ATCC 24459 and Fusarium solani IFO 31093. These fungi were then tested for NG degradation. It was found that the combined culture aerobically degraded 100% of the NG to form a mixture of 55% dinitroglycerin (DNG) and 5% of mononitroglycerin (MNG) in two days, with no further change observed afterward. In the presence of 1.2% glucose and 0.05% ammonium nitrate, NG was completely degraded in two days and a mixture of 20% DNG and 16% MNG was formed after 11 days. Based on these results, it appears that the combination of the fungi in a one to one ratio can be used to degrade both of these energetic compounds.

  18. Evaluation of biodegradable plastics for rubber seedling applications

    NASA Astrophysics Data System (ADS)

    Mansor, Mohd Khairulniza; Dayang Habibah A. I., H.; Kamal, Mazlina Mustafa

    2015-08-01

    The main negative consequence of conventional plastics in agriculture is related to handling the wastes plasticand the associated environmental impact. Hence, a study of different types of potentially biodegradable plastics used for nursery applications have been evaluated on its mechanical,water absorption propertiesand Fourier transform infra-red (FTIR) spectroscopy. Supplied samples from different companies were designated as SF, CF and CO. Most of the polybags exhibited mechanical properties quite similar to the conventional plastics (polybag LDPE). CO polybag which is based on PVA however had extensively higher tensile strength and water absorption properties. FTIR study revealed a characteristics absorbance of conventional plastic, SF, CF and CO biodegradable polybag are associated with polyethylene, poly(butylene adipate-co-terephthalate) (PBAT), polyethylene and polyvinyl alcohol (PVA) structures respectively.

  19. Biodegradation of biodiesel fuels

    SciTech Connect

    Zhang, X.; Haws, R.; Wright, B.; Reese, D.; Moeller, G.; Peterson, C.

    1995-12-31

    Biodiesel fuel test substances Rape Ethyl Ester (REE), Rape Methyl Ester (RME), Neat Rape Oil (NR), Say Methyl Ester (SME), Soy Ethyl Ester (SEE), Neat Soy Oil (NS), and proportionate combinations of RME/diesel and REE/diesel were studied to test the biodegradability of the test substances in an aerobic aquatic environment using the EPA 560/6-82-003 Shake Flask Test Method. A concurrent analysis of Phillips D-2 Reference Diesel was also performed for comparison with a conventional fuel. The highest rates of percent CO{sub 2} evolution were seen in the esterified fuels, although no significant difference was noted between them. Ranges of percent CO{sub 2} evolution for esterified fuels were from 77% to 91%. The neat rape and neat soy oils exhibited 70% to 78% CO{sub 2} evolution. These rates were all significantly higher than those of the Phillips D-2 reference fuel which evolved from 7% to 26% of the organic carbon to CO{sub 2}. The test substances were examined for BOD{sub 5} and COD values as a relative measure of biodegradability. Water Accommodated Fraction (WAF) was experimentally derived and BOD{sub 5} and COD analyses were carried out with a diluted concentration at or below the WAF. The results of analysis at WAF were then converted to pure substance values. The pure substance BOD{sub 5} and COD values for test substances were then compared to a control substance, Phillips D-2 Reference fuel. No significant difference was noted for COD values between test substances and the control fuel. (p > 0.20). The D-2 control substance was significantly lower than all test substances for BCD, values at p << 0.01. RME was also significantly lower than REE (p < 0.05) and MS (p < 0.01) for BOD{sub 5} value.

  20. Taking advantage of natural biodegradation

    SciTech Connect

    Butler, W.A.; Bartlett, C.L.

    1995-12-31

    A chemical manufacturing facility in central New Jersey evaluated alternatives to address low levels of volatile organic compounds (VOCs) in groundwater. Significant natural attenuation of VOCs was observed in groundwater, and is believed to be the result of natural biodegradation, commonly referred to as intrinsic bioremediation. A study consisting of groundwater sampling and analysis, field monitoring, and transport modeling was conducted to evaluate and confirm this phenomenon. The primary conclusion that can be drawn from the study is that observed natural attenuation of VOCs in groundwater is due to natural biodegradation. Based on the concept that natural biodegradation will minimize contaminant migration, bioventing has been implemented to remove the vadose-zone source of VOCs to groundwater. Taking advantage of natural biodegradation has resulted in significant cost savings compared to implementing a conventional groundwater pump-and-treat system, while still protecting human health and the environment.

  1. Biodegradable Peptide-Silica Nanodonuts.

    PubMed

    Maggini, Laura; Travaglini, Leana; Cabrera, Ingrid; Castro-Hartmann, Pablo; De Cola, Luisa

    2016-03-07

    We report hybrid organosilica toroidal particles containing a short peptide sequence as the organic component of the hybrid systems. Once internalised in cancer cells, the presence of the peptide allows for interaction with peptidase enzymes, which attack the nanocarrier effectively triggering its structural breakdown. Moreover, these biodegradable nanovectors are characterised by high cellular uptake and exocytosis, showing great potential as biodegradable drug carriers. To demonstrate this feature, doxorubicin was employed and its delivery in HeLa cells investigated.

  2. Chiral separation of phenylalanine and tryptophan by capillary electrophoresis using a mixture of β-CD and chiral ionic liquid ([TBA] [L-ASP]) as selectors.

    PubMed

    Yujiao, Wu; Guoyan, Wang; Wenyan, Zhao; Hongfen, Zhang; Huanwang, Jing; Anjia, Chen

    2014-05-01

    In this paper, a simple, effective and green capillary electrophoresis separation and detection method was developed for the quantification of underivatized amino acids (dl-phenylalanine; dl-tryptophan) using β-Cyclodextrin and chiral ionic liquid ([TBA] [l-ASP]) as selectors. Separation parameters such as buffer concentrations, pH, β-CD and chiral ionic liquid concentrations and separation voltage were investigated for the enantioseparation in order to achieve the maximum possible resolution. A good separation was achieved in a background electrolyte composed of 15 mm sodium tetraborate, 5 mm β-CD and 4 mm chiral ionic liquid at pH 9.5, and an applied voltage of 10 kV. Under optimum conditions, linearity was achieved within concentration ranges from 0.08 to 10 µg/mL for the analytes with correlation coefficients from 0.9956 to 0.9998, and the analytes were separated in less than 6 min with efficiencies up to 970,000 plates/m. The proposed method was successfully applied to the determination of amino acid enantiomers in compound amino acids injections, such as 18AA-I, 18AA-II and 3AA.

  3. Biodegradation of nitroaromatic compounds.

    PubMed

    Spain, J C

    1995-01-01

    Nitroaromatic compounds are released into the biosphere almost exclusively from anthropogenic sources. Some compounds are produced by incomplete combustion of fossil fuels; others are used as synthetic intermediates, dyes, pesticides, and explosives. Recent research revealed a number of microbial systems capable of transforming or biodegrading nitroaromatic compounds. Anaerobic bacteria can reduce the nitro group via nitroso and hydroxylamino intermediates to the corresponding amines. Isolates of Desulfovibrio spp. can use nitroaromatic compounds as their source of nitrogen. They can also reduce 2,4,6-trinitrotoluene to 2,4,6-triaminotoluene. Several strains of Clostridium can catalyze a similar reduction and also seem to be able to degrade the molecule to small aliphatic acids. Anaerobic systems have been demonstrated to destroy munitions and pesticides in soil. Fungi can extensively degrade or mineralize a variety of nitroaromatic compounds. For example, Phanerochaete chrysosporium mineralizes 2,4-dinitrotoluene and 2,4,6-trinitrotoluene and shows promise as the basis for bioremediation strategies. The anaerobic bacteria and the fungi mentioned above mostly transform nitroaromatic compounds via fortuitous reactions. In contrast, a number of nitroaromatic compounds can serve as growth substrates for aerobic bacteria. Removal or productive metabolism of nitro groups can be accomplished by four different strategies. (a) Some bacteria can reduce the aromatic ring of dinitro and trinitro compounds by the addition of a hydride ion to form a hydride-Meisenheimer complex, which subsequently rearomatizes with the elimination of nitrite. (b) Monooxygenase enzymes can add a single oxygen atom and eliminate the nitro group from nitrophenols. (c) Dioxygenase enzymes can insert two hydroxyl groups into the aromatic ring and precipitate the spontaneous elimination of the nitro group from a variety of nitroaromatic compounds. (d) Reduction of the nitro group to the corresponding

  4. Pressure and temperature effects on 2H spin-lattice relaxation times and 1H chemical shifts in tert-butyl alcohol- and urea-D2O solutions

    NASA Astrophysics Data System (ADS)

    Yoshida, Koji; Ibuki, Kazuyasu; Ueno, Masakatsu

    1998-01-01

    The pressure and temperature effects of hydrophobic hydration were studied by NMR spectroscopy. The 1H chemical shifts (δ) were measured at 7.7, 29.9, and 48.4 °C under high pressure up to 294 MPa for HDO contained as impurity in neat D2O, 1 mol kg-1 tert-butyl alcohol (TBA)-D2O, and 1 mol kg-1 urea-D2O solutions, for the methyl group of TBA in the TBA-D2O solution, and for the amino group of urea in the urea-D2O solution. The 2H spin-lattice relaxation times (T1) were measured under the same conditions as the chemical shift measurements for D2O in neat D2O, TBA-D2O and urea-D2O solutions with organic contents up to 8 mol%. The following features are observed for the pressure effect on δ (HDO) and 2H-T1 in TBA-D2O solutions: (1) The δ (HDO) exhibits a downfield shift relative to that in neat D2O, and the difference of δ (HDO) between TBA solution and neat D2O becomes larger with increasing pressure at lower temperature. (2) The decrement of the rotational correlation time of water in the hydration shell of TBA (τcs) relative to the value at atmospheric pressure is smaller than that in the bulk (τc0). (3) The pressure coefficients of T1 are positive in dilute solutions but are negative in more than 4 to 5 mol% solutions. These results suggest that the hydrophobic hydration shell of TBA is different than the open structure of water present in bulk, and resists pressure more strongly than the open structure of water in the bulk. In solutions of 4 to 5 mol%, the hydration shell collapses. On the other hand, the τcs in the hydration shell of urea is slightly larger than that in bulk water at lower pressure, but is obviously larger at higher pressure. In view of the rotational motion of water molecules, urea seems to strengthen the water structure slightly rather than weaken it, although δ (HDO) approaches that in the bulk with pressure. It is difficult to classify urea into a structure maker or a breaker.

  5. Alcohol project

    SciTech Connect

    Not Available

    1980-12-01

    It is reported that Savannah Foods and Industries, in a joint venture with United States Sugar Corporation have applied for a loan guarantee for the production of alcohol from agricultural commodities. The two phase program calls for research and development, before a prototype plant will be built for the conversion of cellulosic compounds found in bagasse into alcohol for use as a fuel.

  6. Alcohol Facts

    MedlinePlus

    ... Families? Why Is It So Hard to Quit Drugs? Effects of Drugs Drug Use Hurts Other People Drug Use Hurts ... This Section Signs of Alcohol Abuse and Addiction Effects of Alcohol on Brains and Bodies Previous ... Treatment Work? Treatment and Rehab Resources About the ...

  7. Alcoholism & depression.

    PubMed

    Hall, Mellisa

    2012-10-01

    One out of 2 Americans report drinking on a routine basis, making the excessive consumption of alcohol the third leading cause of preventable death in America (). Alcoholism and depression are common comorbidities that home healthcare professionals frequently encounter. To achieve the best patient outcomes, alcoholism should be addressed initially. Although all age groups are at risk, alcoholism and depression occur in more than 8 percent of older adults. Prevention through identifying alcohol use early in adolescence is vital to reduce the likelihood of alcohol dependence. This article provides an overview of the long-term effects of alcohol abuse, including alcoholic cirrhosis and hepatic encephalopathy. The diagnostic criteria for substance dependence and ideas for nonthreatening screening questions to use with patients who are adolescent or older are discussed. While providing patient care, home healthcare nurses share the patient's intimate home environment. This environment is perceived as a safe haven by the patient and home care nurses can take advantage of counseling and treatment opportunities in this nonthreatening environment.

  8. Biodegradation of Polyethoxylated Nonylphenols

    PubMed Central

    Ruiz, Yassellis; Medina, Luis; Borusiak, Margarita; Ramos, Nairalith; Pinto, Gilberto; Valbuena, Oscar

    2013-01-01

    Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEOx), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEOx and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO15, as unique carbon source, is described. The most efficient NPEO15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO15 medium. The NPEO15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h−1 and 96.3 h, respectively. PMID:23936727

  9. Biodegradation of sorbed chemicals in soil

    SciTech Connect

    Scow, K.M.; Fan, S.; Johnson, C.; Ma, G.M.

    1995-06-01

    Rates of biodegradation of sorbed chemicals are usually lower in soil than in aqueous systems, in part because sorption reduces the availability of the chemical to microorganisms. Biodegradation, sorption, and diffusion occur simultaneously and are tightly coupled. In soil, the rate of biodegradation is a function of a chemical`s diffusion coefficient, sorption partition coefficient, the distance it must diffuse from the site of sorption to microbial populations that can degrade it, and its biodegradation rate constant. A model (DSB model) was developed that describes biodegradation of chemicals limited in the availability by sorption and diffusion. Different kinetics expressions describe biodegradation depending on whether the reaction is controlled by mass transfer (diffusion and sorption) or the intrinsic biodegradation rate, and whether biodegradation begins during or after the majority of sorption has occurred. We tested the hypothesis that there is a direct relationship between how strongly a chemical is sorbed and the chemical`s biodegradation rate. In six soils with different organic carbon contents, there was no relationship between the extent or rate of biodegradation and the sorption partition coefficient for phenanthrene. Aging of phenanthrene residues in soil led to a substantial reduction in the rate of biodegradation compared to biodegradation rates of recently added phenanthrene. Considerable research has focused on identification and development of techniques for enhancing in situ biodegradation of sorbed chemicals. Development of such techniques, especially those involving inoculation with microbial strains, should consider physical mass transfer limitations and potential decreases in bioavailability over time. 4 refs., 3 figs., 1 tab.

  10. Alcohol Energy Drinks

    MedlinePlus

    ... Home / About Addiction / Alcohol / Alcohol Energy Drinks Alcohol Energy Drinks Read 24059 times font size decrease font size increase font size Print Email Alcohol energy drinks (AEDs) or Caffeinated alcoholic beverages (CABs) are ...

  11. Alcohol during Pregnancy

    MedlinePlus

    ... Home > Pregnancy > Is it safe? > Alcohol during pregnancy Alcohol during pregnancy E-mail to a friend Please ... and fetal alcohol spectrum disorders. How does drinking alcohol during pregnancy affect your baby's health? Drinking alcohol ...

  12. Effects of the Biodegradation on Biodegradable Polymer Blends and Polypropylene

    NASA Astrophysics Data System (ADS)

    Pereira, R. C. T.; Franchetti, S. M. M.; Agnelli, J. A. M.; Mattoso, L. H. C.

    2008-08-01

    The large use of plastics in the world generates a large amount of waste which persists around 200 years in the environment. To minimize this effect is important to search some new polymer materials: the blends of biodegradable polymers with synthetic polymers. It is a large area that needs an intensive research to investigate the blends properties and its behavior face to the different treatments to aim at the biodegradation. The blends used in this work are: some biodegradable polymers such as: poly(hydroxybutyrate) (PHB) and poly(ɛ-polycaprolactone) (PCL) with a synthetic polymer, polypropylene (PP), in lower concentration. These blends were prepared using an internal mixer (Torque Rheometer), and pressed. These films were submitted to fungus biotreatment. The films analyses will be carried out by Fourier Transform Infrared (FTIR), UV-Vis absorption (UV-Vis), Scanning Electronic Microscopy (SEM), DSC and TGA.

  13. Alcohol conversion

    DOEpatents

    Wachs, Israel E.; Cai, Yeping

    2002-01-01

    Preparing an aldehyde from an alcohol by contacting the alcohol in the presence of oxygen with a catalyst prepared by contacting an intimate mixture containing metal oxide support particles and particles of a catalytically active metal oxide from Groups VA, VIA, or VIIA, with a gaseous stream containing an alcohol to cause metal oxide from the discrete catalytically active metal oxide particles to migrate to the metal oxide support particles and to form a monolayer of catalytically active metal oxide on said metal oxide support particles.

  14. Developments in metallic biodegradable stents.

    PubMed

    Hermawan, H; Dubé, D; Mantovani, D

    2010-05-01

    Interest in metallic degradable biomaterials research has been growing in the last decade. Both scientific journals and patent databases record a high increase in publications in this area. Biomedical implants with temporary function, such as coronary stents, are the targeted applications for this novel class of biomaterials. It is expected that stents made of degradable biomaterials, named biodegradable stents, will provide a temporary opening into a narrowed arterial vessel until the vessel remodels and will progressively disappear thereafter. Biodegradable stents made of metal have recently been progressed into preclinical tests in humans after their first introduction in early 2000s. By referring to patents and journal publications, this paper reviews the developments in biodegradable stents, with emphasis on those made of metals, starting from the first design ideas to validation testing.

  15. On the origin of mesoscale structures in aqueous solutions of tertiary butyl alcohol: the mystery resolved.

    PubMed

    Sedlák, Marián; Rak, Dmytro

    2014-03-13

    We have performed a detailed experimental study on aqueous solutions of tertiary butyl alcohol which were a subject of long-standing controversies regarding the puzzling presence of virtually infinitely stable large-scale structures in such solutions occurring at length scales exceeding appreciably dimensions of individual molecules, referred to also as mesoscale structures. A combination of static and dynamic light scattering yielding information on solution structure and dynamics and gas chromatography coupled with mass spectrometry yielding information on chemical composition was used. We show that tertiary butyl alcohol clearly exhibiting such structures upon mixing with water does not contain any propylene oxide, which was previously considered as a source of these structures (an impurity expected to be present in all commercial samples of TBA). More importantly, we show that no mesoscale structures are generated upon addition of propylene oxide to aqueous solutions of TBA. The ternary system TBA/water/propylene oxide exhibits homogeneous mixing of the components on mesoscales. We show that the source of the mesoscale structures is a mesophase separation of appreciably more hydrophobic compounds than propylene oxide. These substances are explicitly analytically identified as well as their disappearance upon filtering out the mesoscale structures by nanopore filtration. We clearly show which substances are disappearing upon filtration and which are not. This enables us to estimate with rather high probability the chemical composition of the mesoscale structures. Visualization of large-scale structures via nanoparticle tracking analysis is also presented. Video capturing the mesoscale particles as well as their Brownian motion can be found in the Supporting Information .

  16. Petroleum biodegradation in marine environments.

    PubMed

    Harayama, S; Kishira, H; Kasai, Y; Shutsubo, K

    1999-08-01

    Petroleum-based products are the major source of energy for industry and daily life. Petroleum is also the raw material for many chemical products such as plastics, paints, and cosmetics. The transport of petroleum across the world is frequent, and the amounts of petroleum stocks in developed countries are enormous. Consequently, the potential for oil spills is significant, and research on the fate of petroleum in a marine environment is important to evaluate the environmental threat of oil spills, and to develop biotechnology to cope with them. Crude oil is constituted from thousands of components which are separated into saturates, aromatics, resins and asphaltenes. Upon discharge into the sea, crude oil is subjected to weathering, the process caused by the combined effects of physical, chemical and biological modification. Saturates, especially those of smaller molecular weight, are readily biodegraded in marine environments. Aromatics with one, two or three aromatic rings are also efficiently biodegraded; however, those with four or more aromatic ring are quite resistant to biodegradation. The asphaltene and resin fractions contain higher molecular weight compounds whose chemical structures have not yet been resolved. The biodegradability of these compounds is not yet known. It is known that the concentrations of available nitrogen and phosphorus in seawater limit the growth and activities of hydrocarbon-degrading microorganisms in a marine environment. In other words, the addition of nitrogen and phosphorus fertilizers to an oil-contaminated marine environment can stimulate the biodegradation of spilled oil. This notion was confirmed in the large-scale operation for bioremediation after the oil spill from the Exxon Valdez in Alaska. Many microorganisms capable of degrading petroleum components have been isolated. However, few of them seem to be important for petroleum biodegradation in natural environments. One group of bacteria belonging to the genus

  17. Alcoholics Anonymous

    MedlinePlus

    ... Help What's New Read Daily Reflections Make a Contribution Go to Online Bookstore Welcome to Alcoholics Anonymous ® ... and Twelve & Twelve | 75th Anniversary Edition | Make a contribution | Self-Support Press/Media | Archives & History | A.A. ...

  18. Alcohol Intolerance

    MedlinePlus

    ... or other preservatives Chemicals, grains or other ingredients Histamine, a byproduct of fermentation or brewing In some ... in some people, possibly as a result of histamines contained in some alcoholic beverages. Your immune system ...

  19. Alcoholic ketoacidosis

    MedlinePlus

    Tests may include: Arterial blood gases (measure the acid/base balance and oxygen level in blood) Blood alcohol ... PA: Elsevier Saunders; 2013:chap 161. Seifter JL. Acid-Base disorders. In: Goldman L, Schafer AI, eds. Goldman's ...

  20. Alcohol withdrawal

    MedlinePlus

    ... Seeing or feeling things that aren't there (hallucinations) Seizures Severe confusion ... alcohol withdrawal. You will be watched closely for hallucinations and other signs of delirium tremens. Treatment may ...

  1. Biodegradation of ethyl t-butyl ether (ETBE), methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) by Gordonia terrae.

    PubMed

    Hernandez-Perez, G; Fayolle, F; Vandecasteele, J P

    2001-01-01

    Gordonia terrae strain IFP 2001 was selected from activated sludge for its capacity to grow on ethyl t-butyl ether (ETBE) as sole carbon and energy source. ETBE was stoichiometrically degraded to t-butyl alcohol (TBA) and the activity was inducible. A constitutive strain, G. terrae IFP 2007, derived from strain IFP 2001, was also selected. Methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) were not used as carbon and energy sources by the two strains, but cometabolic degradation of MTBE and TAME was demonstrated, to TBA and t-amyl alcohol (TAA) respectively, in the presence of a carbon source such as ethanol. No two-carbon compound was detected during growth on ETBE, but formate was produced during cometabolic degradation of MTBE or TAME. A monooxygenase was involved in the degradation of ethers, because no degradation of ETBE was observed under anaerobic conditions and the presence of a cytochrome P-450 was demonstrated in G. terrae IFP 2001 after induction by cultivation on ETBE.

  2. Comparative evaluation of anaerobic biodegradability of hydrocarbons and fatty derivatives currently used as drilling fluids.

    PubMed

    Steber, J; Herold, C P; limia, J M

    1995-08-01

    The examination of a number of potential and currently used carrier fluids for invert emulsion drilling fluids in the ECETOC screening test revealed clear differences with respect to their easy anaerobic biodegradability. Fatty acid- and alcohol-based ester oils exhibited excellent anaerobic degradation to the gaseous final end products of the methanogenic degradation pathway, methane and carbon dioxide. Mineral oils, dialkyl ethers, alpha-olefins, polyalphaolefins, linear alkylbenzenes and an acetal-derivative were not or only slowly degraded. Although the poor degradation results obtained in the stringent ECETOC screening test may not be regarded as final proof of anaerobic recalcitrance, nevertheless, these results were found to be in line with the present understanding of the structural requirements for anaerobic biodegradability of chemicals. The validity of the conclusions drawn is corroborated by published results on the anaerobic biodegradation behaviour of ester oils, mineral oils and alkylbenzenes in marine sediments.

  3. Preferential biodegradation of structurally dissimilar dyes from a mixture by Brevibacillus laterosporus.

    PubMed

    Kurade, Mayur B; Waghmode, Tatoba R; Govindwar, Sanjay P

    2011-09-15

    Biodegradation of a mixture containing seven commercial textile dyes with different structures and color properties has been investigated by an ecofriendly strain--Brevibacillus laterosporus MTCC 2298. It showed 87% decolorization in terms of ADMI removal (American Dye Manufacturing Institute) within 24h. The effective decolorization of dye mixture was attained in the presence of metal salt--CaCl(2) and nitrogen sources. The induction of oxido-reductive enzymes such as veratryl alcohol oxidase, tyrosinase, NADH-DCIP reductase and azo reductase was found to be responsible for biotransformation of dyes. High performance thin layer chromatography exposed the mechanism of preferential biodegradation of dyes at different time periods. Significant change in the high pressure liquid chromatography and Fourier transform infrared spectroscopy of sample before and after treatment confirmed the biodegradation of dye mixture. Phytotoxicity study revealed the much less toxic nature of the metabolites produced after the degradation of dyes mixture.

  4. Biodegradable Pectin/clay Aerogels

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. Addition of multivalent cations (Ca2+ and Al3+) resulted in apparent crosslinking of the polymer, and enhancement of aerogel p...

  5. Concomitant aerobic biodegradation of benzene and thiophene

    SciTech Connect

    Dyreborg, S.; Arvin, E.; Broholm, K.

    1998-05-01

    The concomitant aerobic biodegradation of benzene and thiophene was investigated in microcosm experiments using a groundwater enrichment culture. Benzene was biodegraded within 1 d, whereas thiophene could not be biodegraded as the sole source of carbon and energy. Some interesting phenomena were observed when both benzene and thiophene were present. In most cases, removal of thiophene was observed, and the removal occurred concomitantly with the biodegradation of benzene, suggesting that benzene was used as a primary substrate in the cometabolic biodegradation of thiophene. No biodegradation of the two compounds was observed for some combinations of concentrations, suggesting that thiophene could act as an inhibitor to benzene biodegradation. However, this effect could be overcome if more benzene was added to the microcosm. Residual concentrations of benzene and thiophene were observed in some microcosms and the data indicated that the biodegradation of the two compounds stopped when a critical threshold ratio between the concentrations of thiophene and benzene was reached. This ratio varied between 10 and 20. Results from modeling the biodegradation data suggested that thiophene was cometabolized concomitantly with the biodegradation of benzene and that the biodegradation may be described by a modified model based on a traditional model with an inhibition term incorporated.

  6. Deciding to quit drinking alcohol

    MedlinePlus

    ... Alcohol abuse - quitting drinking; Quitting drinking; Quitting alcohol; Alcoholism - deciding to quit ... pubmed/23698791 . National Institute on Alcohol Abuse and Alcoholism. Alcohol and health. www.niaaa.nih.gov/alcohol- ...

  7. Identification of Biomarker Genes To Predict Biodegradation of 1,4-Dioxane

    PubMed Central

    Gedalanga, Phillip B.; Pornwongthong, Peerapong; Mora, Rebecca; Chiang, Sheau-Yun Dora; Baldwin, Brett; Ogles, Dora

    2014-01-01

    Bacterial multicomponent monooxygenase gene targets in Pseudonocardia dioxanivorans CB1190 were evaluated for their use as biomarkers to identify the potential for 1,4-dioxane biodegradation in pure cultures and environmental samples. Our studies using laboratory pure cultures and industrial activated sludge samples suggest that the presence of genes associated with dioxane monooxygenase, propane monooxygenase, alcohol dehydrogenase, and aldehyde dehydrogenase are promising indicators of 1,4-dioxane biotransformation; however, gene abundance was insufficient to predict actual biodegradation. A time course gene expression analysis of dioxane and propane monooxygenases in Pseudonocardia dioxanivorans CB1190 and mixed communities in wastewater samples revealed important associations with the rates of 1,4-dioxane removal. In addition, transcripts of alcohol dehydrogenase and aldehyde dehydrogenase genes were upregulated during biodegradation, although only the aldehyde dehydrogenase was significantly correlated with 1,4-dioxane concentrations. Expression of the propane monooxygenase demonstrated a time-dependent relationship with 1,4-dioxane biodegradation in P. dioxanivorans CB1190, with increased expression occurring after over 50% of the 1,4-dioxane had been removed. While the fraction of P. dioxanivorans CB1190-like bacteria among the total bacterial population significantly increased with decrease in 1,4-dioxane concentrations in wastewater treatment samples undergoing active biodegradation, the abundance and expression of monooxygenase-based biomarkers were better predictors of 1,4-dioxane degradation than taxonomic 16S rRNA genes. This study illustrates that specific bacterial monooxygenase and dehydrogenase gene targets together can serve as effective biomarkers for 1,4-dioxane biodegradation in the environment. PMID:24632253

  8. Alcoholic sialosis.

    PubMed

    Kastin, B; Mandel, L

    2000-01-01

    Sialosis (sialadenosis) is a term used to describe a disorder that involves both secretory and parenchymal changes of the major salivary glands, most commonly the parotid. Seen often in a dental office, it is recognized as an indolent, bilateral, non-inflammatory, non-neoplastic, soft, symmetrical, painless and persistent enlargement of the parotid glands. Four major entities have commonly been associated with this disorder. They are alcoholism, endocrinopathy (particularly diabetes mellitus), maLnutrition and idiopathic. We are reporting a case of alcoholic sialosis with its clinical and diagnostic aspects. It is important for the dental practitioner to recognize sialosis, because it often indicates the existence of an unsuspected systemic disease.

  9. Alcohol and pregnancy

    MedlinePlus

    Drinking alcohol during pregnancy; Fetal alcohol syndrome - pregnancy; FAS - fetal alcohol syndrome ... group of defects in the baby known as fetal alcohol syndrome. Symptoms can include: Behavior and attention problems Heart ...

  10. Alcohol and Hepatitis

    MedlinePlus

    ... Home » Living with Hepatitis » Daily Living: Alcohol Viral Hepatitis Menu Menu Viral Hepatitis Viral Hepatitis Home For ... Alcohol for Veterans and the Public Alcohol and Hepatitis: Entire Lesson Overview Alcohol is one of the ...

  11. Alcohol and Hepatitis

    MedlinePlus

    ... code here Enter ZIP code here Daily Living: Alcohol for Veterans and the Public Alcohol and Hepatitis: Entire Lesson Overview Alcohol is one ... related to choices you make about your lifestyle . Alcohol and fibrosis Fibrosis is the medical term for ...

  12. Alcoholism and Minority Populations.

    ERIC Educational Resources Information Center

    Watts, Thomas D.; Wright, Roosevelt, Jr.

    1991-01-01

    Briefly discusses some aspects of the role of the state and the position of minorities in respect to alcoholism policies and services. Includes case study of a Black alcoholic. Refers readers to studies on Black alcoholism, Native American alcoholism, Hispanic alcoholism, and Asian-American alcoholism. (Author/NB)

  13. Propargyl alcohol

    Integrated Risk Information System (IRIS)

    Propargyl alcohol ; CASRN 107 - 19 - 7 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  14. Allyl alcohol

    Integrated Risk Information System (IRIS)

    Allyl alcohol ; CASRN 107 - 18 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  15. Isobutyl alcohol

    Integrated Risk Information System (IRIS)

    Isobutyl alcohol ; CASRN 78 - 83 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  16. Recent advances in biodegradable nanocomposites.

    PubMed

    Pandey, Jitendra K; Kumar, A Pratheep; Misra, Manjusri; Mohanty, Amar K; Drzal, Lawrence T; Singh, Raj Pal

    2005-04-01

    There is growing interest in developing bio-based products and innovative process technologies that can reduce the dependence on fossil fuel and move to a sustainable materials basis. Biodegradable bio-based nanocomposites are the next generation of materials for the future. Renewable resource-based biodegradable polymers including cellulosic plastic (plastic made from wood), corn-derived plastics, and polyhydroxyalkanoates (plastics made from bacterial sources) are some of the potential biopolymers which, in combination with nanoclay reinforcement, can produce nanocomposites for a variety of applications. Nanocomposites of this category are expected to possess improved strength and stiffness with little sacrifice of toughness, reduced gas/water vapor permeability, a lower coefficient of thermal expansion, and an increased heat deflection temperature, opening an opportunity for the use of new, high performance, lightweight green nanocomposite materials to replace conventional petroleum-based composites. The present review addresses this green material, including its technical difficulties and their solutions.

  17. Engineering Flame Retardant Biodegradable Nanocomposites

    NASA Astrophysics Data System (ADS)

    He, Shan; Yang, Kai; Guo, Yichen; Zhang, Linxi; Pack, Seongchan; Davis, Rachel; Lewin, Menahem; Ade, Harald; Korach, Chad; Kashiwagi, Takashi; Rafailovich, Miriam

    2013-03-01

    Cellulose-based PLA/PBAT polymer blends can potentially be a promising class of biodegradable nanocomposites. Adding cellulose fiber reinforcement can improve mechanical properties of biodegradable plastics, but homogeneously dispersing hydrophilic cellulose in the hydrophobic polymer matrix poses a significant challenge. We here show that resorcinol diphenyl phosphates (RDP) can be used to modify the surface energy, not only reducing phase separation between two polymer kinds but also allowing the cellulose particles and the Halloysite clay to be easily dispersed within polymer matrices to achieve synergy effect using melt blending. Here in this study we describe the use of cellulose fiber and Halloysite clay, coated with RDP surfactant, in producing the flame retardant polymer blends of PBAT(Ecoflex) and PLA which can pass the stringent UL-94 V0 test. We also utilized FTIR, SEM and AFM nanoindentation to elucidate the role RDP plays in improving the compatibility of biodegradable polymers, and to determine structure property of chars that resulted in composites that could have optimized mechanical and thermal properties. Supported by Garcia Polymer Center and NSF Foundation.

  18. Effect of short-term exposure to methyl-tert-butyl ether and tert-butyl alcohol on the hatch rate and development of the African catfish, Clarias gariepinus.

    PubMed

    Moreels, David; Lodewijks, Pieter; Zegers, Hans; Rurangwa, Eugène; Vromant, Nico; Bastiaens, Leen; Diels, Ludo; Springael, Dirk; Merckx, Roel; Ollevier, Frans

    2006-02-01

    Methyl tert-butyl ether (MTBE), a synthetic chemical used as a fuel additive, has been detected more frequently in the environment than previously. In this study, we examine the effects of MTBE (up to 100 mg/L) and its primary metabolite tertbutyl alcohol (TBA) (up to 1,400 mg/L) on the hatch rate and larval development of the African catfish Clarias gariepinus. Exposure to higher MTBE concentrations resulted in deformed eyes, mouthparts, and spinal cord and in increased larval mortality. Methyl tert-butyl ether exposure had no significant impact on egg viability, whereas TBA induced a decline of hatch rate. The MTBE can be regarded as a pollutant with toxicological effects on catfish larvae at concentrations above 50 mg/L. Although such concentrations greatly surpass present-day concentrations found in surface water (0.088 mg/L), concentrations up to 200 mg/L have been detected in groundwater.

  19. Phenanthrene biodegradation kinetics in unsaturated soils

    SciTech Connect

    Johnson, C.R.; Scow, K.M.

    1995-12-31

    Organic compounds when sorbed to soil solids are thought to be unavailable to soil microorganisms. The biodegradation kinetics of sorbed chemicals should thus be influenced by sorption/desorption processes as well as by the metabolic capacities of soil microbes. In the research, phenanthrene, a hydrophobic polyaromatic hydrocarbon, was used as a model compound to investigate the biodegradation kinetics of strongly sorbing organic compounds in soil. Biodegradation kinetics for phenanthrene in seven soils with moisture contents near field capacity were measured during a six and one half month experiment. Phenanthrene biodegradation rates initially increased in all soils and then declined. The declining portion of the biodegradation rate versus time plots exhibited either first order or biphasic kinetics. Both first order and biphasic kinetics are consistent with models which link microbial degradation to substrate sorption/desorption from equilibrium and kinetically controlled sorption sites. No single rate constant or analytical expression adequately captured the complexity of the observed biodegradation rates. This result is again consonant with a process derived from coupled biological and physical systems. Biodegradation kinetics were quantified using a combination of fitted and descriptive parameters. Significant correlations exist between several of the descriptive parameters. The correlations observed between descriptive biodegradation parameters mirror correlations expected from the hypothesized underlying biological process and help evince the influence this underlying process exerts on observed biodegradation kinetics.

  20. A review of plastic waste biodegradation.

    PubMed

    Zheng, Ying; Yanful, Ernest K; Bassi, Amarjeet S

    2005-01-01

    With more and more plastics being employed in human lives and increasing pressure being placed on capacities available for plastic waste disposal, the need for biodegradable plastics and biodegradation of plastic wastes has assumed increasing importance in the last few years. This review looks at the technological advancement made in the development of more easily biodegradable plastics and the biodegradation of conventional plastics by microorganisms. Additives, such as pro-oxidants and starch, are applied in synthetic materials to modify and make plastics biodegradable. Recent research has shown that thermoplastics derived from polyolefins, traditionally considered resistant to biodegradation in ambient environment, are biodegraded following photo-degradation and chemical degradation. Thermoset plastics, such as aliphatic polyester and polyester polyurethane, are easily attacked by microorganisms directly because of the potential hydrolytic cleavage of ester or urethane bonds in their structures. Some microorganisms have been isolated to utilize polyurethane as a sole source of carbon and nitrogen source. Aliphatic-aromatic copolyesters have active commercial applications because of their good mechanical properties and biodegradability. Reviewing published and ongoing studies on plastic biodegradation, this paper attempts to make conclusions on potentially viable methods to reduce impacts of plastic waste on the environment.

  1. Biodegradation of high molecular weight polylactic acid

    NASA Astrophysics Data System (ADS)

    Stloukal, Petr; Koutny, Marek; Sedlarik, Vladimir; Kucharczyk, Pavel

    2012-07-01

    Polylactid acid seems to be an appropriate replacement of conventional non-biodegradable synthetic polymer primarily due to comparable mechanical, thermal and processing properties in its high molecular weight form. Biodegradation of high molecular PLA was studied in compost for various forms differing in their specific surface area. The material proved its good biodegradability under composting conditions and all investigated forms showed to be acceptable for industrial composting. Despite expectations, no significant differences in resulting mineralizations were observed for fiber, film and powder sample forms with different specific surface areas. The clearly faster biodegradation was detected only for the thin coating on porous material with high specific surface area.

  2. Alcohol use and safe drinking

    MedlinePlus

    ... to alcohol use Get into trouble with the law, family members, friends, school, or dates because of alcohol THE EFFECTS OF ALCOHOL Alcoholic drinks have different amounts of alcohol in them. Beer is about 5% alcohol, although some beers can ...

  3. Interstellar Alcohols

    NASA Technical Reports Server (NTRS)

    Charnley, S. B.; Kress, M. E.; Tielens, A. G. G. M.; Millar, T. J.

    1995-01-01

    We have investigated the gas-phase chemistry in dense cores where ice mantles containing ethanol and other alcohols have been evaporated. Model calculations show that methanol, ethanol, propanol, and butanol drive a chemistry leading to the formation of several large ethers and esters. Of these molecules, methyl ethyl ether (CH3OC2H5) and diethyl ether (C2H5)2O attain the highest abundances and should be present in detectable quantities within cores rich in ethanol and methanol. Gas-phase reactions act to destroy evaporated ethanol and a low observed abundance of gas-phase C,H,OH does not rule out a high solid-phase abundance. Grain surface formation mechanisms and other possible gas-phase reactions driven by alcohols are discussed, as are observing strategies for the detection of these large interstellar molecules.

  4. Biodegradable sizing agents from soy protein via controlled hydrolysis and dis-entanglement for remediation of textile effluents.

    PubMed

    Yang, Maiping; Xu, Helan; Hou, Xiuliang; Zhang, Jie; Yang, Yiqi

    2017-03-01

    Fully biodegradable textile sizes with satisfactory performance properties were developed from soy protein with controlled hydrolysis and dis-entanglement to tackle the intractable environmental issues associated with the non-biodegradable polyvinyl alcohol (PVA) in textile effluents. PVA derived from petroleum is the primary sizing agent due to its excellent sizing performance on polyester-containing yarns, especially in increasingly prevailing high-speed weaving. However, due to the poor biodegradability, PVA causes serious environmental pollution, and thus, should be substituted with more environmentally friendly polymers. Soy protein treated with high amount of triethanolamine was found with acceptable sizing properties. However, triethanolamine is also non-biodegradable and originated from petroleum, therefore, is not an ideal additive. In this research, soy sizes were developed from soy protein treated with glycerol, the biodegradable triol that could also be obtained from soy. The soy sizes had good film properties, adhesion to polyester and abrasion resistance close to PVA, rendering them qualified for sizing applications. Regarding desizing, consumption of water and energy for removal of soy size could be remarkably decreased, comparing to removal of PVA. Moreover, with satisfactory degradability, the wastewater containing soy sizes was readily dischargeable after treated in activated sludge for two days. In summary, the fully biodegradable soy sizes had potential to substitute PVA for sustainable textile processing.

  5. Bacterial Degradation of tert-Amyl Alcohol Proceeds via Hemiterpene 2-Methyl-3-Buten-2-ol by Employing the Tertiary Alcohol Desaturase Function of the Rieske Nonheme Mononuclear Iron Oxygenase MdpJ

    PubMed Central

    Schuster, Judith; Schäfer, Franziska; Hübler, Nora; Brandt, Anne; Rosell, Mònica; Härtig, Claus; Harms, Hauke; Müller, Roland H.

    2012-01-01

    Tertiary alcohols, such as tert-butyl alcohol (TBA) and tert-amyl alcohol (TAA) and higher homologues, are only slowly degraded microbially. The conversion of TBA seems to proceed via hydroxylation to 2-methylpropan-1,2-diol, which is further oxidized to 2-hydroxyisobutyric acid. By analogy, a branched pathway is expected for the degradation of TAA, as this molecule possesses several potential hydroxylation sites. In Aquincola tertiaricarbonis L108 and Methylibium petroleiphilum PM1, a likely candidate catalyst for hydroxylations is the putative tertiary alcohol monooxygenase MdpJ. However, by comparing metabolite accumulations in wild-type strains of L108 and PM1 and in two mdpJ knockout mutants of strain L108, we could clearly show that MdpJ is not hydroxylating TAA to diols but functions as a desaturase, resulting in the formation of the hemiterpene 2-methyl-3-buten-2-ol. The latter is further processed via the hemiterpenes prenol, prenal, and 3-methylcrotonic acid. Likewise, 3-methyl-3-pentanol is degraded via 3-methyl-1-penten-3-ol. Wild-type strain L108 and mdpJ knockout mutants formed isoamylene and isoprene from TAA and 2-methyl-3-buten-2-ol, respectively. It is likely that this dehydratase activity is catalyzed by a not-yet-characterized enzyme postulated for the isomerization of 2-methyl-3-buten-2-ol and prenol. The vitamin requirements of strain L108 growing on TAA and the occurrence of 3-methylcrotonic acid as a metabolite indicate that TAA and hemiterpene degradation are linked with the catabolic route of the amino acid leucine, including an involvement of the biotin-dependent 3-methylcrotonyl coenzyme A (3-methylcrotonyl-CoA) carboxylase LiuBD. Evolutionary aspects of favored desaturase versus hydroxylation pathways for TAA conversion and the possible role of MdpJ in the degradation of higher tertiary alcohols are discussed. PMID:22194447

  6. Structure-biodegradability study and computer-automated prediction of aerobic biodegradation of chemicals

    SciTech Connect

    Klopman, G.; Tu, M.

    1997-09-01

    It is shown that a combination of two programs, MultiCASE and META, can help assess the biodegradability of industrial organic materials in the ecosystem. MultiCASE is an artificial intelligence computer program that had been trained to identify molecular substructures believed to cause or inhibit biodegradation and META is an expert system trained to predict the aerobic biodegradation products of organic molecules. These two programs can be used to help evaluate the fate of disposed chemicals by estimating their biodegradability and the nature of their biodegradation products under conditions that may model the environment.

  7. [Out of addictions: Alcohol, or alcohol to alcohol].

    PubMed

    Simmat-Durand, L; Vellut, N; Lejeune, C; Jauffret-Roustide, M; Mougel, S; Michel, L; Planche, M

    2016-06-29

    Pathways from alcoholism to recovery are documented; less often are those from drug addiction to alcoholism. Biographical approaches allow analyzing how people change their uses and talk about their trajectories of recovery.

  8. Constitutive framework for biodegradable polymers with applications to biodegradable stents.

    PubMed

    Soares, João S; Moore, James E; Rajagopal, Kumbakonan R

    2008-01-01

    Biodegradable polymeric stents must provide mechanical support of the stenotic artery wall up to several months while being subjected to cyclic loading that affects the degradation process. To understand the applicability and efficacy of biodegradable polymers, a two-pronged approach involving experiments and theory is necessary. This article addresses the second aspect, the development of a theoretical framework within which the behavior of such materials can be studied. We present a constitutive model for polymers that undergo deformation induced-degradation. For our purpose, degradation is the scission of chemical bonds of the backbone chain, results in molecular weight reduction, and consequently in the commonly observed softening. A model of a solid capable of degradation, which in its absence responds like an elastic solid, is developed. We assume the existence of a scalar field that reflects the local state of degradation and changes the properties of the material. A rate equation for the measure of degradation that depends on strain is coupled with the balance of linear momentum. Uniaxial extension of a body, which in the absence of degradation behaves as a neo-Hookean elastic solid, exhibits stress relaxation, creep, and hysteresis, due to degradation.

  9. Here today, gone tomorrow: biodegradable soft robots

    NASA Astrophysics Data System (ADS)

    Rossiter, Jonathan; Winfield, Jonathan; Ieropoulos, Ioannis

    2016-04-01

    One of the greatest challenges to modern technologies is what to do with them when they go irreparably wrong or come to the end of their productive lives. The convention, since the development of modern civilisation, is to discard a broken item and then procure a new one. In the 20th century enlightened environmentalists campaigned for recycling and reuse (R and R). R and R has continued to be an important part of new technology development, but there is still a huge problem of non-recyclable materials being dumped into landfill and being discarded in the environment. The challenge is even greater for robotics, a field which will impact on all aspects of our lives, where discards include motors, rigid elements and toxic power supplies and batteries. One novel solution is the biodegradable robot, an active physical machine that is composed of biodegradable materials and which degrades to nothing when released into the environment. In this paper we examine the potential and realities of biodegradable robotics, consider novel solutions to core components such as sensors, actuators and energy scavenging, and give examples of biodegradable robotics fabricated from everyday, and not so common, biodegradable electroactive materials. The realisation of truly biodegradable robots also brings entirely new deployment, exploration and bio-remediation capabilities: why track and recover a few large non-biodegradable robots when you could speculatively release millions of biodegradable robots instead? We will consider some of these exciting developments and explore the future of this new field.

  10. Current trends in biodegradable polyhydroxyalkanoates.

    PubMed

    Chanprateep, Suchada

    2010-12-01

    The microbial polyesters known as polyhydroxyalkanoates (PHAs) positively impact global climate change scenarios by reducing the amount of non-degradable plastic used. A wide variety of different monomer compositions of PHAs has been described, as well as their future prospects for applications where high biodegradability or biocompatibility is required. PHAs can be produced from renewable raw materials and are degraded naturally by microorganisms that enable carbon dioxide and organic compound recycling in the ecosystem, providing a buffer to climate change. This review summarizes recent research on PHAs and addresses the opportunities as well as challenges for their place in the global market.

  11. Investigation of the proinflammatory potential of biodegradable nanoparticle drug delivery systems in the lung

    SciTech Connect

    Dailey, L.A. . E-mail: lea_ann.dailey@kcl.ac.uk; Jekel, N.; Fink, L.; Gessler, T.; Schmehl, T.; Wittmar, M.; Kissel, T.; Seeger, W.

    2006-08-15

    Particulate nanocarriers have been praised for their advantageous drug delivery properties in the lung, such as avoidance of macrophage clearance mechanisms and long residence times. However, instilled non-biodegradable polystyrene nanospheres with small diameters and thus large surface areas have been shown to induce pulmonary inflammation. This study examines the potential of biodegradable polymeric nanoparticles composed of poly(lactic-co-glycolic acid) (PLGA) and the novel PLGA derivative, diethylaminopropylamine polyvinyl alcohol-grafted-poly(lactic-co-glycolic acid) (DEAPA-PVAL-g-PLGA), to provoke inflammatory responses in the murine lung after intratracheal instillation. Lactate dehydrogenase (LDH) release, protein concentration, MIP-2 mRNA induction, and polymorphonucleocyte (PMN) recruitment in the bronchial alveolar lavage fluid (BALF) were used to evaluate an inflammatory response in Balb-C mice. Two sizes of polystyrene (PS) nanospheres (diameters: 75 nm and 220 nm) were included in the study for comparison. All nanoparticle suspensions were instilled at concentrations of 1 {mu}g/{mu}l and 2.5 {mu}g/{mu}l, representative of an estimated 'therapeutic dose' and a concentrated 'dose' of particles. In all experiments, the 75 nm PS particles exhibited elevated responses for the inflammatory markers investigated. In contrast, biodegradable particles of comparable hydrodynamic diameter showed a significantly lower inflammatory response. The most marked differences were observed in the extent of PMN recruitment. While the 75 nm and 220 nm PS nanospheres exhibited 41 and 74% PMN within the total BALF cell population after 24 h, respectively, PMN recruiting in lungs instilled with both types of biodegradable particles did not exceed values of the negative isotonic glucose control. In conclusion, evidence suggests that biodegradable polymeric nanoparticles designed for pulmonary drug delivery may not induce the same inflammatory response as non-biodegradable

  12. Biodegradable polymers for microencapsulation of drugs.

    PubMed

    Park, Jae Hyung; Ye, Mingli; Park, Kinam

    2005-01-31

    Drug delivery has become increasingly important mainly due to the awareness of the difficulties associated with a variety of old and new drugs. Of the many polymeric drug delivery systems, biodegradable polymers have been used widely as drug delivery systems because of their biocompatibility and biodegradability. The majority of biodegradable polymers have been used in the form of microparticles, from which the incorporated drug is released to the environment in a controlled manner. The factors responsible for controlling the drug release rate are physicochemical properties of drugs, degradation rate of polymers, and the morphology and size of microparticles. This review discusses the conventional and recent technologies for microencapsulation of the drugs using biodegradable polymers. In addition, this review presents characteristics and degradation behaviors of biodegradable polymers which are currently used in drug delivery.

  13. Biodegradable polymers for electrospinning: towards biomedical applications.

    PubMed

    Kai, Dan; Liow, Sing Shy; Loh, Xian Jun

    2014-12-01

    Electrospinning has received much attention recently due to the growing interest in nano-technologies and the unique material properties. This review focuses on recent progress in applying electrospinning technique in production of biodegradable nanofibers to the emerging field of biomedical. It first introduces the basic theory and parameters of nanofibers fabrication, with focus on factors affecting the morphology and fiber diameter of biodegradable nanofibers. Next, commonly electrospun biodegradable nanofibers are discussed, and the comparison of the degradation rate of nanoscale materials with macroscale materials are highlighted. The article also assesses the recent advancement of biodegradable nanofibers in different biomedical applications, including tissue engineering, drug delivery, biosensor and immunoassay. Future perspectives of biodegradable nanofibers are discussed in the last section, which emphasizes on the innovation and development in electrospinning of hydrogels nanofibers, pore size control and scale-up productions.

  14. Older Adults and Alcohol

    MedlinePlus

    ... Alcohol Exposure Support & Treatment Alcohol Policy Special Populations & Co-occurring Disorders Publications & Multimedia Brochures & Fact Sheets NIAAA ... are here Home » Alcohol & Your Health » Special Populations & Co-occurring Disorders » Older Adults In this Section Underage ...

  15. Fetal Alcohol Syndrome

    MedlinePlus

    ... The diagnosis of fetal alcohol syndrome. Deutsches Arztebaltt International. 2013;110:703. Ungerer M, et al. In utero alcohol exposure, epigenetic changes and their consequences. Alcohol Research: Current Reviews. 2013;35:37. Coriale G, et al. ...

  16. Fetal Alcohol Syndrome

    MedlinePlus

    ... Conditions Frequently Asked Questions Español Condiciones Chinese Conditions Fetal Alcohol Syndrome Read in Chinese What is Fetal Alcohol Syndrome (FAS)? Fetal Alcohol Syndrome (FAS) describes changes in ...

  17. Alcoholic liver disease

    MedlinePlus

    Liver disease due to alcohol; Cirrhosis or hepatitis - alcoholic; Laennec's cirrhosis ... Alcoholic liver disease occurs after years of heavy drinking. Over time, scarring and cirrhosis can occur. Cirrhosis is the ...

  18. Simultaneous copper, cobalt and phenol removal from aqueous solutions by alternating biosorption and biodegradation.

    PubMed

    Tsekova, K; Ganeva, S; Hristov, A; Todorova, D; Beschkov, V

    2011-01-01

    A strategy for removal of heavy metals and phenol from wastewaters is proposed. It involves consecutive cation biosorption by fungi, phenol biodegradation by the yeast association Candida sp. 2326 + Candida sp. 2327 and regeneration. Copper and cobalt removal from aqueous solutions containing 80-120 mg/L phenol by biosorption, using Rhizopus archizus cells immobilized onto poly (vinyl alcohol), was investigated by conducting a series of batch experiments. The removal efficiencies were 81% for Cu and 5% for Co. The residual concentrations of Cu (1.9 mg/L) and of Co (9.5 mg/L) did not change the biodegradation dynamics of phenol. A quantitative biodegradation of 120 mg/L phenol proceeded within 22 h. After biodegradation of phenol, the removal efficiencies achieved by biosorption after regeneration were 90% for Cu and 44% for Co. It was found that copper and cobalt form positively charged complexes with phenol. This complex formation hinders the retention of Cu and Co by the biosorbent and reduces the uptake of their cations.

  19. Promoting Diabetic Wound Therapy Using Biodegradable rhPDGF-Loaded Nanofibrous Membranes

    PubMed Central

    Lee, Cheng-Hung; Liu, Kuo-Sheng; Chang, Shang-Hung; Chen, Wei-Jan; Hung, Kuo-Chun; Liu, Shih-Jung; Pang, Jong-Hwei S.; Juang, Jyuhn-Huarng; Chou, Chung-Chuan; Chang, Po-Cheng; Chen, Yi-Ting; Wang, Fu-Shing

    2015-01-01

    Abstract The nanofibrous biodegradable drug-loaded membranes that sustainably released recombinant human platelet-derived growth factor (rhPDGF-BB) to repair diabetic wounds were developed in this work. rhPDGF-BB and poly(lactic-co-glycolic acid) (PLGA) were mixed in hexafluoroisopropyl alcohol, followed by the electrospinning of the solutions into biodegradable membranes to equip the nanofibrous membranes. An elution technique and an enzyme-linked immunosorbent assay kit were used to determine the rhPDGF-BB release rates in vitro and in vivo from this membrane. Eighteen Sprague-Dawley streptozotocin-induced diabetic rats were randomized into 3 groups: rhPDGF-BB-loaded nanofibrous membrane group, PLGA only membrane group, and conventional gauze sponge group for the wound associated with diabetes of rat in each group. The nanofibrous biodegradable membranes released effective concentrations of rhPDGF-BB for over 21 days. The nanofibrous rhPDGF-BB-loaded PLGA membranes contained more water and were further hydrophilic than PLGA only fibers. The rhPDGF-BB-loaded PLGA membranes considerably helped the diabetic wounds repairing. Furthermore, the proliferative cells and angiogenesis of rats associated with diabetes by rhPDGF-BB-loaded nanofibrous membranes were greater than those of other groups, owing to the increased matrix metalloproteinase 9. These biodegradable rhPDGF-BB-loaded membranes were effective in treating diabetic wounds as very advanced accelerators during the initial phases of wound-healing process. PMID:26632682

  20. Formulation of microbial cocktails for BTEX biodegradation.

    PubMed

    Nagarajan, Karthiga; Loh, Kai-Chee

    2015-02-01

    BTEX biodegradation by a mixed community of micro-organisms offers a promising approach in terms of cost-effectiveness and elimination of secondary pollution. Two bacterial strains, Pseudomonas putida F1 and Pseudomonas stutzeri OX1 were chosen to formulate synthetic consortia based on their ability to biodegrade the mono-aromatic compounds. Benzene and toluene supported the growth of both the strains; while ethyl benzene and o-xylene were only utilized as growth substrates by P. putida F1 and P. stutzeri OX1, respectively. In a mixed substrate system, P. putida F1 exhibited incomplete removal of o-xylene while P. stutzeri OX1 displayed cometabolic removal of ethyl benzene with dark coloration of the growth medium. The biodegradation potential of the two Pseudomonas species complemented each other and offered opportunities to explore their performance as a co-culture for enhanced BTEX biodegradation. Several microbial formulations were concocted and their BTEX biodegradation characteristics were evaluated. Mixed culture biodegradation ascertained the advantages of the co-culture over the individual Pseudomonas species. This study also emphasized the significance of inoculum density and species proportion while concocting preselected micro-organisms for enhanced BTEX biodegradation.

  1. Design Strategies for Fluorescent Biodegradable Polymeric Biomaterials

    PubMed Central

    Zhang, Yi; Yang, Jian

    2013-01-01

    The marriage of biodegradable polymer and fluorescent imaging has resulted in an important area of polymeric biomaterials: biodegradable fluorescent polymers. Researchers have put significant efforts on developing versatile fluorescent biomaterials due to their promising in biological/biomedical labeling, tracking, monitoring, imaging, and diagnostic applications, especially in drug delivery, tissue engineering, and cancer imaging applications. Biodegradable fluorescent polymers can function not only as implant biomaterials but also as imaging probes. Currently, there are two major classes of biodegradable polymers used as fluorescent materials. The first class is the combination of non-fluorescent biodegradable polymers and fluorescent agents such as organic dyes and quantum dots. Another class of polymers shows intrinsic photoluminescence as polymers by themselves carrying integral fluorescent chemical structures in or pendent to their polymer backbone, such as Green Fluorescent protein (GFP), and the recently developed biodegradable photoluminescent polymer (BPLP). Thus there is no need to conjugate or encapsulate additional fluorescent materials for the latter. In the present review, we will review the fluorescent biodegradable polymers with emphases on material fluorescence mechanism, design criteria for fluorescence, and their cutting-edge applications in biomedical engineering. We expect that this review will provide insightful discussion on the fluorescent biomaterial design and lead to innovations for the development of the next generation of fluorescent biomaterials and fluorescence-based biomedical technology. PMID:23710326

  2. Aged refinery hydrocarbon biodegradation in soil

    SciTech Connect

    Drake, E.N.; Stokley, K.E.; Calcavecchio, P.

    1995-12-31

    Aged hydrocarbon biodegradation was investigated as a potential cleanup technology for refinery soil. Well-mixed field soil was amended with water and nutrients and tilled weekly for one year in laboratory mesocosms to stimulate biodegradation. Freon infrared analysis of total petroleum hydrocarbons (TPH), and gas chromatography/mass spectrometry (GC/MS) analysis of polynuclear aromatic hydrocarbons (PAHs) and triterpane biomarkers were used to determine the extent of biodegradation. Significant reductions in TPH (up to 68%) and methylene chloride extractable material (up to 55%) were observed. The combined trimethylated phenanthrene/anthracenes (C3P/A) were even more highly depleted than TPH. Nutrient amendment increased TPH, methylene chloride, and C3P/A removal, but not biomarker concentrations. Significant reduction of two to five ring PAHs occurred. Expected depletion patterns for PAHs were observed except in the case of naphthalene and derivatives, phenanthrene/anthracene and derivatives, and chrysene. A possible explanation is that the more readily degradable PAHs were already highly biodegraded before the study and the remaining portions were less available for biodegradation. These results are consistent with reports on the effects of aging on PAH biodegradation in soil. Biodegradation was influenced by PAH structure and molecular weight.

  3. Biodegradable and compostable alternatives to conventional plastics

    PubMed Central

    Song, J. H.; Murphy, R. J.; Narayan, R.; Davies, G. B. H.

    2009-01-01

    Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all ‘good’ or petrochemical-based products are all ‘bad’. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated ‘home’ composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted. PMID:19528060

  4. Biodegradable and compostable alternatives to conventional plastics.

    PubMed

    Song, J H; Murphy, R J; Narayan, R; Davies, G B H

    2009-07-27

    Packaging waste forms a significant part of municipal solid waste and has caused increasing environmental concerns, resulting in a strengthening of various regulations aimed at reducing the amounts generated. Among other materials, a wide range of oil-based polymers is currently used in packaging applications. These are virtually all non-biodegradable, and some are difficult to recycle or reuse due to being complex composites having varying levels of contamination. Recently, significant progress has been made in the development of biodegradable plastics, largely from renewable natural resources, to produce biodegradable materials with similar functionality to that of oil-based polymers. The expansion in these bio-based materials has several potential benefits for greenhouse gas balances and other environmental impacts over whole life cycles and in the use of renewable, rather than finite resources. It is intended that use of biodegradable materials will contribute to sustainability and reduction in the environmental impact associated with disposal of oil-based polymers. The diversity of biodegradable materials and their varying properties makes it difficult to make simple, generic assessments such as biodegradable products are all 'good' or petrochemical-based products are all 'bad'. This paper discusses the potential impacts of biodegradable packaging materials and their waste management, particularly via composting. It presents the key issues that inform judgements of the benefits these materials have in relation to conventional, petrochemical-based counterparts. Specific examples are given from new research on biodegradability in simulated 'home' composting systems. It is the view of the authors that biodegradable packaging materials are most suitable for single-use disposable applications where the post-consumer waste can be locally composted.

  5. Role of microbial adhesion in phenanthrene biodegradation by Pseudomonas fluorescens LP6a

    NASA Astrophysics Data System (ADS)

    Abbasnezhad, Hassan

    Biodegradation of poorly water soluble hydrocarbons, such as n-alkanes and polycyclic aromatic hydrocarbons (PAHs) is often limited by the low availability of the pollutant to microbes. Adhesion of microorganisms to the oil-water interface can influence this availability. Our approach was to study a range of compounds and mechanisms to promote the adhesion of a hydrophilic PAH degrading bacterium, Pseudomonas fluorescens LP6a, to an oil-water interface and examine the effect on biodegradation of phenanthrene by the bacteria. The cationic surfactants cetylpyridinium chloride (CPC), poly-L-lysine and chlorhexidine gluconate (CHX) and the long chain alcohols 1-dodecanol, 2-dodecanol and farnesol increased the adhesion of P. fluorescens LP6a to n-hexadecane from ca. 30% to ca. 90% of suspended cells adhering. The alcohols also caused a dramatic change in the oil-water contact angle of the cell surface, increasing it from 24° to 104°, whereas the cationic compounds had little effect. In contrast, cationic compounds changed the electrophoretic mobility of the bacteria, reducing the mean zeta potential from --23 to --7 mV in 0.01M potassium phosphate buffer, but the alcohols had no effect on zeta potential. This results illustrate that alcohols acted through altering the cell surface hydrophobicity, whereas cationic surfactants changed the surface charge density. Phenanthrene was dissolved in heptamethylnonane and introduced to the aqueous growth medium, hence forming a two phase system. Introducing 1-dodecanol at concentrations of 217, 820 or 4100 mg/L resulted in comparable increases in phenanthrene biodegradation of about 30% after 120 h incubation with non-induced cultures. After 100 h of incubation with LP6a cultures induced with 2-aminobenzoate, 4.5% of the phenanthrene was mineralized by cultures versus more than 10% by the cultures containing initial 1-dodecanol or 2-dodecanol concentrations of 120 or 160 mg/L. The production and accumulation of metabolites in

  6. Antibiotic releasing biodegradable scaffolds for osteomyelitis.

    PubMed

    Nair, Manitha; Krishnan, Amit

    2014-01-01

    Osteomyelitis is characterized by progressive inflammatory bone degeneration. In the management of chronic osteomyelitis, it is necessary to remove the infected bone tissue followed by implantation of an antibiotic releasing biomaterial that can release antibiotic locally for long periods of time. The main carrier used in clinics for this application is polymethylmethacrylate (PMMA) (Eg. Septopal beads). However, major drawback is the need of an additional surgery to remove the beads after therapy, as PMMA is not biodegradable. This necessitates the requirement of biodegradable carrier systems that can release antibiotics and simultaneously support debrided bone formation. This review summarizes biodegradable carrier systems that have been reported for the localised treatment and prophylaxis of osteomyelitis.

  7. CONTROLLED METHYL TERTIARY BUTYL ETHER (MTBE) EXPOSURE TO HUMANS THROUGH DERMAL, INGESTION, AND INHALATION ROUTES AND THE RESULTANT BIOMARKER TERTIARY BUTYL ALCOHOL (TBA) AS MEASURED IN EXHALED BREATH AND VENOUS BLOOD

    EPA Science Inventory

    Radiocarbon (14C) measurements provide an estimate of the fraction of carbon in a sample that is biogenic. In September 1997 during SCOS97 a series of 3-h canister samples of ambient air were collected at the Azusa air monitoring station during morning and afternoon periods. ...

  8. New perspectives in plastic biodegradation.

    PubMed

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution.

  9. Engineered biosynthesis of biodegradable polymers.

    PubMed

    Jambunathan, Pooja; Zhang, Kechun

    2016-08-01

    Advances in science and technology have resulted in the rapid development of biobased plastics and the major drivers for this expansion are rising environmental concerns of plastic pollution and the depletion of fossil-fuels. This paper presents a broad view on the recent developments of three promising biobased plastics, polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene succinate (PBS), well known for their biodegradability. The article discusses the natural and recombinant host organisms used for fermentative production of monomers, alternative carbon feedstocks that have been used to lower production cost, different metabolic engineering strategies used to improve product titers, various fermentation technologies employed to increase productivities and finally, the different downstream processes used for recovery and purification of the monomers and polymers.

  10. Biodegradable polyesters from renewable resources.

    PubMed

    Tsui, Amy; Wright, Zachary C; Frank, Curtis W

    2013-01-01

    Environmental concerns have led to the development of biorenewable polymers with the ambition to utilize them at an industrial scale. Poly(lactic acid) and poly(hydroxyalkanoates) are semicrystalline, biorenewable polymers that have been identified as the most promising alternatives to conventional plastics. However, both are inherently susceptible to brittleness and degradation during thermal processing; we discuss several approaches to overcome these problems to create a balance between durability and biodegradability. For example, copolymers and blends can increase ductility and the thermal-processing window. Furthermore, chain modifications (e.g., branching/crosslinking), processing techniques (fiber drawing/annealing), or additives (plasticizers/nucleating agents) can improve mechanical properties and prevent thermal degradation during processing. Finally, we examine the impacts of morphology on end-of-life degradation to complete the picture for the most common renewable polymers.

  11. Biodegradation of halogenated organic compounds.

    PubMed Central

    Chaudhry, G R; Chapalamadugu, S

    1991-01-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  12. Development of a biochemical process for production of alcohol fuel from peat. Final technical report, June 1, 1981-June 30, 1983

    SciTech Connect

    Levy, P.F.; de Riel, S.R.; Heneghan, E.P.; Cheng, L.K.; Sanderson, J.E.

    1983-07-29

    This report relates progress in the development of a process for production of mixed alcohol fuel from peat. The process has four steps - pretreatment of peat to promote biodegradability, anaerobic fermentation to produce organic acids, electrolytic oxidation of organic acids to olefins, and hydration of the olefins to alcohols. Since production of alcohols by hydration of olefins is an acknowledged technology, the development program focuses on demonstrating technical feasibility of the other three steps. 70 references, 70 figures, 61 tables.

  13. Alcoholic metabolic emergencies.

    PubMed

    Allison, Michael G; McCurdy, Michael T

    2014-05-01

    Ethanol intoxication and ethanol use are associated with a variety of metabolic derangements encountered in the Emergency Department. In this article, the authors discuss alcohol intoxication and its treatment, dispel the myth that alcohol intoxication is associated with hypoglycemia, comment on electrolyte derangements and their management, review alcoholic ketoacidosis, and end with a section on alcoholic encephalopathy.

  14. Fetal Alcohol Exposure

    MedlinePlus

    ... of the National Academies (IOM) diagnostic categories: 4 » Fetal Alcohol Syndrome (FAS) » Partial FAS (pFAS) » Alcohol-Related Neurodevelopmental Disorder ( ... 301.443.3860 Relevant Clinical Diagnoses IOM Diagnoses Fetal Alcohol Syndrome (FAS) Fetal Alcohol Syndrome (FAS) was the first ...

  15. Nurses' Attitudes towards Alcoholics.

    ERIC Educational Resources Information Center

    Speer, Rita D.

    Nurses' attitudes toward the alcoholic can have a profound impact on the person suffering from alcoholism. These attitudes can affect the alcoholic's care and even whether the alcoholic chooses to recover. This study investigated attitudes of approximately 68 nurses employed in hospitals, 49 nurses in treatment facilities, 58 nursing students, and…

  16. Children of Alcoholics.

    ERIC Educational Resources Information Center

    Krois, Deborah Helen

    Although alcoholism has long been considered a serious problem, the impact of parental alcoholism on children has only recently begun to receive attention from researchers and clinicians. A review of the empirical literature on children of alcoholics was conducted and it was concluded that children raised in an alcoholic family are at increased…

  17. Overview of Alcohol Consumption

    MedlinePlus

    ... Work Our Funding Our Staff Jobs & Training Our Location Contact Us You are here Home » Alcohol & Your Health » Overview of Alcohol Consumption In this Section Alcohol Facts & Statistics What Is A Standard Drink? Drinking Levels Defined Overview of Alcohol Consumption ...

  18. Influence of Concentration and Salinity on the Biodegradability of Organic Additives in Hydraulic Fracturing Fluid

    NASA Astrophysics Data System (ADS)

    Mouser, P. J.; Kekacs, D.

    2014-12-01

    One of the risks associated with the use of hydraulic fracturing technologies for energy development is the potential release of hydraulic fracturing-related fluids into surface waters or shallow aquifers. Many of the organic additives used in hydraulic fracturing fluids are individually biodegradable, but little is know on how they will attenuate within a complex organic fluid in the natural environment. We developed a synthetic hydraulic fracturing fluid based on disclosed recipes used by Marcellus shale operators to evaluate the biodegradation potential of organic additives across a concentration (25 to 200 mg/L DOC) and salinity gradient (0 to 60 g/L) similar to Marcellus shale injected fluids. In aerobic aqueous solutions, microorganisms removed 91% of bulk DOC from low SFF solutions and 57% DOC in solutions having field-used SFF concentrations within 7 days. Under high SFF concentrations, salinity in excess of 20 g/L inhibited organic compound biodegradation for several weeks, after which time the majority (57% to 75%) of DOC remained in solution. After SFF amendment, the initially biodiverse lake or sludge microbial communities were quickly dominated (>79%) by Pseudomonas spp. Approximately 20% of added carbon was converted to biomass while the remainder was respired to CO2 or other metabolites. Two alcohols, isopropanol and octanol, together accounted for 2-4% of the initial DOC, with both compounds decreasing to below detection limits within 7 days. Alcohol degradation was associated with an increase in acetone at mg/L concentrations. These data help to constrain the biodegradation potential of organic additives in hydraulic fracturing fluids and guide our understanding of the microbial communities that may contribute to attenuation in surface waters.

  19. Internet Alcohol Marketing and Underage Alcohol Use

    PubMed Central

    McClure, Auden C.; Tanski, Susanne E.; Li, Zhigang; Jackson, Kristina; Morgenstern, Matthis; Li, Zhongze; Sargent, James D.

    2016-01-01

    BACKGROUND AND OBJECTIVE Internet alcohol marketing is not well studied despite its prevalence and potential accessibility and attractiveness to youth. The objective was to examine longitudinal associations between self-reported engagement with Internet alcohol marketing and alcohol use transitions in youth. METHODS A US sample of 2012 youths aged 15 to 20 was surveyed in 2011. An Internet alcohol marketing receptivity score was developed, based on number of positive responses to seeing alcohol advertising on the Internet, visiting alcohol brand Web sites, being an online alcohol brand fan, and cued recall of alcohol brand home page images. We assessed the association between baseline marketing receptivity and both ever drinking and binge drinking (≥6 drinks per occasion) at 1-year follow-up with multiple logistic regression, controlling for baseline drinking status, Internet use, sociodemographics, personality characteristics, and peer or parent drinking. RESULTS At baseline, ever-drinking and binge-drinking prevalence was 55% and 27%, respectively. Many (59%) reported seeing Internet alcohol advertising, but few reported going to an alcohol Web site (6%) or being an online fan (3%). Higher Internet use, sensation seeking, having family or peers who drank, and past alcohol use were associated with Internet alcohol marketing receptivity, and a score of 1 or 2 was independently associated with greater adjusted odds of initiating binge drinking (odds ratio 1.77; 95% confidence interval, 1.13–2.78 and odds ratio 2.15; 95% confidence interval, 1.06–4.37 respectively) but not with initiation of ever drinking. CONCLUSIONS Although high levels of engagement with Internet alcohol marketing were uncommon, most underage youths reported seeing it, and we found a prospective association between receptivity to this type of alcohol marketing and future problem drinking, making additional research and ongoing surveillance important. PMID:26738886

  20. Biodegradation of rocket propellent waste, ammonium perchlorate

    NASA Technical Reports Server (NTRS)

    Naqui, S. M. Z.

    1975-01-01

    The impact of the biodegradation rate of ammonium perchlorate on the environment was studied in terms of growth, metabolic rate, and total biomass of selected animal and plant species. Brief methodology and detailed results are presented.

  1. MOLECULAR BASIS OF BIODEGRADATION OF CHLOROAROMATIC COMPOUNDS

    EPA Science Inventory

    Chlorinated aromatic hydrocarbons are widely used in industry and agriculture, and comprise the bulk of environmental pollutants. Although simple aromatic compounds are biodegradable by a variety of degradative pathways, their halogenated counterparts are more resistant to bacter...

  2. Polyaspartate scale inhibitors -- Biodegradable alternatives to polyacrylates

    SciTech Connect

    Ross, R.J.; Low, K.C.; Shannon, J.E.

    1996-12-01

    Polyaspartates are highly biodegradable alternatives to polyacrylate based scale inhibitors. This paper presents laboratory testing data on polyaspartate inhibitors of calcium and barium mineral scales. The optimum molecular weight for polyaspartate inhibitors of calcium carbonate, calcium sulfate and barium sulfate mineral scales was determined to be between 1,000 and 4,000 Mw (weight average molecular weight as calculated by Size Exclusion Chromatography). For inhibition of calcium carbonate and barium sulfate, polyaspartates in the range of 3,000-4,000 Mw were most effective. For calcium sulfate inhibition, the optimum molecular weight lies in the 1,000 to 2,000 Mw range. Biodegradability data (OECD 301B Ready Biodegradability) on polyaspartates of a variety of molecular weights is also presented which demonstrates the high biodegradability of this class of mineral scale inhibitors.

  3. Biodegradation of the anionic surfactant dialkyl sulphosuccinate

    SciTech Connect

    Hales, S.G. . Port Sunlight Lab.)

    1993-10-01

    A range of Organization for Economic Cooperation and Development (OECD) guideline test systems was used to determine the extent and possible mechanisms of biodegradation of dialkyl sulphosuccinate (DASS, C[sub 6]/C[sub 8]). Primary biodegradation of DASS was virtually complete in OECD guideline tests and in simulations of activated sludge sewage treatment systems under both optimal and adverse conditions, and of an anaerobic digester. Ultimate biodegradation increased form about 50% in ready tests to 94% in more powerful inherent tests. [[sup 14]C]DASS was used to determine the fate of the surfactant in activated sludge and in surface waters. Mechanistic studies were performed to ascertain the biodegradative pathway of [[sup 14]C]DASS. A putative degradation pathway for DASS is proposed.

  4. Phyllosphere yeasts rapidly break down biodegradable plastics.

    PubMed

    Kitamoto, Hiroko K; Shinozaki, Yukiko; Cao, Xiao-Hong; Morita, Tomotake; Konishi, Masaaki; Tago, Kanako; Kajiwara, Hideyuki; Koitabashi, Motoo; Yoshida, Shigenobu; Watanabe, Takashi; Sameshima-Yamashita, Yuka; Nakajima-Kambe, Toshiaki; Tsushima, Seiya

    2011-11-29

    The use of biodegradable plastics can reduce the accumulation of environmentally persistent plastic wastes. The rate of degradation of biodegradable plastics depends on environmental conditions and is highly variable. Techniques for achieving more consistent degradation are needed. However, only a few microorganisms involved in the degradation process have been isolated so far from the environment. Here, we show that Pseudozyma spp. yeasts, which are common in the phyllosphere and are easily isolated from plant surfaces, displayed strong degradation activity on films made from poly-butylene succinate or poly-butylene succinate-co-adipate. Strains of P. antarctica isolated from leaves and husks of paddy rice displayed strong degradation activity on these films at 30°C. The type strain, P. antarctica JCM 10317, and Pseudozyma spp. strains from phyllosphere secreted a biodegradable plastic-degrading enzyme with a molecular mass of about 22 kDa. Reliable source of biodegradable plastic-degrading microorganisms are now in our hands.

  5. OPTIMIZING BTEX BIODEGRADATION UNDER DENITRIFYING CONDITIONS

    EPA Science Inventory

    Laboratory tests were conducted to determine optimum conditions for benzene, toluene, ethylbenzene, and xylene (collectively known as BTEX) biodegradation by aquifer microorganisms under denitrifying conditions. Microcosms, constructed with aquifer samples from Traverse City, Mic...

  6. Alcohol and bone.

    PubMed

    Mikosch, Peter

    2014-01-01

    Alcohol is widely consumed across the world in different cultural and social settings. Types of alcohol consumption differ between (a) light, only occasional consumption, (b) heavy chronic alcohol consumption, and (c) binge drinking as seen as a new pattern of alcohol consumption among teenagers and young adults. Heavy alcohol consumption is detrimental to many organs and tissues, including bones. Osteoporosis is regularly mentioned as a secondary consequence of alcoholism, and chronic alcohol abuse is established as an independent risk factor for osteoporosis. The review will present the different mechanisms and effects of alcohol intake on bone mass, bone metabolism, and bone strength, including alcoholism-related "life-style factors" such as malnutrition, lack of exercise, and hormonal changes as additional causative factors, which also contribute to the development of osteoporosis due to alcohol abuse.

  7. In situ surface biodegradation of restorative materials.

    PubMed

    Padovani, Gc; Fúcio, Sbp; Ambrosano, Gmb; Sinhoreti, Mac; Puppin-Rontani, Rm

    2014-01-01

    SUMMARY This study aimed to evaluate the surface characteristics of restorative materials (roughness, hardness, chemical changes by energy-dispersive spectroscopy [EDX], and scanning electron microscopy [SEM]) submitted to in situ biodegradation. Fifteen discs of each material (IPS e.max [EM], Filtek Supreme [FS], Vitremer [VI], Ketac Molar Easymix [KM], and Amalgam GS-80 [AM]) were fabricated in a metallic mold (4.0 mm × 1.5 mm). Roughness, hardness, SEM, and EDX were then evaluated. Fifteen healthy volunteers used a palatal device containing one disc of each restorative material for seven days. After the biodegradation, the roughness, hardness, SEM, and EDX were once again evaluated. Data obtained from the roughness and hardness evaluations were submitted to Kolmogorov-Smirnov and Tukey-Kramer tests (p<0.05). All esthetic restorative materials showed a significant increase in the roughness after biodegradation. Before biodegradation, significant differences in the hardness among the materials were seen: EM>AM>FS>KM>VI. After biodegradation, the hardness was significantly altered among the materials studied: EM>AM>FS=KM>VI, along with a significant increase in the hardness for AM, KM, and VI. SEM images indicated degradation on the surface of all materials, showing porosities, cracks, and roughness. Furthermore, after biodegradation, FS showed the presence of Cl, K, and Ca on the surface, while F was not present on the VI and KM surfaces. EM and AM did not have alterations in their chemical composition after biodegradation. It was concluded that the dental biofilm accumulation in situ on different restorative materials is a material-dependent parameter. Overall, all materials changed after biodegradation: esthetic restorative materials showed increased roughness, confirmed by SEM, and the ionomer materials and silver amalgam showed a significantly higher hardness. Finally, the initial chemical composition of the composite resin and ionomer materials evaluated was

  8. Alcohol fuels

    SciTech Connect

    Not Available

    1990-07-01

    Ethanol is an alcohol made from grain that can be blended with gasoline to extend petroleum supplies and to increase gasoline octane levels. Congressional proposals to encourage greater use of alternative fuels could increase the demand for ethanol. This report evaluates the growth potential of the ethanol industry to meet future demand increases and the impacts increased production would have on American agriculture and the federal budget. It is found that ethanol production could double or triple in the next eight years, and that American farmers could provide the corn for this production increase. While corn growers would benefit, other agricultural segments would not; soybean producers, for example could suffer for increased corn oil production (an ethanol byproduct) and cattle ranchers would be faced with higher feed costs because of higher corn prices. Poultry farmers might benefit from lower priced feed. Overall, net farm cash income should increase, and consumers would see slightly higher food prices. Federal budget impacts would include a reduction in federal farm program outlays by an annual average of between $930 million (for double current production of ethanol) to $1.421 billion (for triple production) during the eight-year growth period. However, due to an partial tax exemption for ethanol blended fuels, federal fuel tax revenues could decrease by between $442 million and $813 million.

  9. Anaerobic biodegradation of hexazinone in four sediments.

    PubMed

    Wang, Huili; Xu, Shuxia; Tan, Chengxia; Wang, Xuedong

    2009-05-30

    Anaerobic biodegradation of hexazinone was investigated in four sediments (L1, L2, Y1 and Y2). Results showed that the L2 sediment had the highest biodegradation potential among four sediments. However, the Y1 and Y2 sediments had no capacity to biodegrade hexazinone. Sediments with rich total organic carbon, long-term contamination history by hexazinone and neutral pH may have a high biodegradation potential because the former two factors can induce the growth of microorganisms responsible for biodegradation and the third factor can offer suitable conditions for biodegradation. The addition of sulfate or nitrate as electron acceptors enhanced hexazinone degradation. As expected, the addition of electron donors (lactate, acetate or pyruvate) substantially inhibited the degradation. In natural environmental conditions, the effect of intermediate A [3-(4-hydroxycyclohexyl)-6-(dimethylamino)-1-methyl-1,3,5-triazine-2,4(1H, 3H)dione] on anaerobic hexazinone degradation was negligible because of its low level.

  10. Substrate inhibition kinetics of phenol biodegradation

    SciTech Connect

    Goudar, C.T.; Ganji, S.H.; Pujar, B.G.; Strevett, K.A.

    2000-02-01

    Phenol biodegradation was studied in batch experiments using an acclimated inoculum and initial phenol concentrations ranging from 0.1 to 1.3 g/L. Phenol depletion an associated microbial growth were monitored over time to provide information that was used to estimate the kinetics of phenol biodegradation. Phenol inhibited biodegradation at high concentrations, and a generalized substrate inhibition model based on statistical thermodynamics was used to describe the dynamics of microbial growth in phenol. For experimental data obtained in this study, the generalized substrate inhibition model reduced to a form that is analogous to the Andrews equation, and the biokinetic parameters {micro}{sub max}, maximum specific growth; K{sub s}, saturation constant; and K{sub i}, inhibition constant were estimated as 0.251 h{sup {minus}1}, 0.011 g/L, and 0.348 g/L, respectively, using a nonlinear least squares technique. Given the wide variability in substrate inhibition models used to describe phenol biodegradation, an attempt was made to justify selection of particular model based on theoretical considerations. Phenol biodegradation data from nine previously published studies were used in the generalized substrate inhibition model to determine the appropriate form of the substrate inhibition model. In all nine cases, the generalized substrate inhibition model reduced to a form analogous to the Andrews equation suggesting the suitability of the Andrews equation to describe phenol biodegradation data.

  11. Biodegradability of commercial and weathered diesel oils

    PubMed Central

    Mariano, Adriano Pinto; Bonotto, Daniel Marcos; de Franceschi de Angelis, Dejanira; Pirôllo, Maria Paula Santos; Contiero, Jonas

    2008-01-01

    This work aimed to evaluate the capability of different microorganisms to degrade commercial diesel oil in comparison to a weathered diesel oil collected from the groundwater at a petrol station. Two microbiological methods were used for the biodegradability assessment: the technique based on the redox indicator 2,6 -dichlorophenol indophenol (DCPIP) and soil respirometric experiments using biometer flasks. In the former we tested the bacterial cultures Staphylococcus hominis, Kocuria palustris, Pseudomonas aeruginosa LBI, Ochrobactrum anthropi and Bacillus cereus, a commercial inoculum, consortia obtained from soil and groundwater contaminated with hydrocarbons and a consortium from an uncontaminated area. In the respirometric experiments it was evaluated the capability of the native microorganisms present in the soil from a petrol station to biodegrade the diesel oils. The redox indicator experiments showed that only the consortia, even that from an uncontaminated area, were able to biodegrade the weathered diesel. In 48 days, the removal of the total petroleum hydrocarbons (TPH) in the respirometric experiments was approximately 2.5 times greater when the commercial diesel oil was used. This difference was caused by the consumption of labile hydrocarbons, present in greater quantities in the commercial diesel oil, as demonstrated by gas chromatographic analyses. Thus, results indicate that biodegradability studies that do not consider the weathering effect of the pollutants may over estimate biodegradation rates and when the bioaugmentation is necessary, the best strategy would be that one based on injection of consortia, because even cultures with recognised capability of biodegrading hydrocarbons may fail when applied isolated. PMID:24031193

  12. Physicochemical properties and biodegradability of crude oil

    SciTech Connect

    Sugiura, Keiji; Ishihara, Masami; Shimauchi, Toshitsugu; Harayama, Shigeaki

    1997-01-01

    The biodegradation of four different crude oil samples, namely, Arabian light, Dubai, Maya, and Shengli, by acinetobacter sp. T4 and by a microbial consortium called SM8 was examined. SM8 exhibited higher activity than Acinetobacter for the biodegradation of all four crude oil samples. The degree of biodegradation of crude oil components differed according to the crude oil, the saturated fraction being more susceptible to biodegradation than the aromatic fraction in all the crude oil samples. The extent of biodegradation by acinetobacter and SM8 was found to be in the order of Arabian light > Dubai > Maya = Shengli; the crude oil samples with higher APl gravity being more susceptible to biodegradation. Saturated compounds of smaller molecular weight were preferentially degraded by both cultures. Acinetobacter could not degrade polycyclic aromatic compounds in the crude oil samples such as (alkyl)naphthalenes, (alky)phenanthrenes, (alkyl)fluorenes, and (alkyl)dibenzothiophenes. However, this strain was capable of degrading more than 10% of the molecules in the aromatic fraction of Arabian light crude oil. An NMR analysis demonstrated that the alkyl side chain of some aromatic molecules was degraded by this organism. In contrast, SM8 degraded the polycyclic aromatic compounds in the crude oil samples, the extent of degradation being in the order of Maya > Shengli > Arabian light > Dubai. 17 refs., 4 figs., 4 tabs.

  13. Immersed multilayer biodegradable ureteral stent with reformed biodegradation: An in vitro experiment.

    PubMed

    Yang, Ganggang; Xie, Hua; Huang, Yichen; Lv, Yiqing; Zhang, Mingqing; Shang, Yafeng; Zhou, Junmei; Wang, Liping; Wang, Jin-Ye; Chen, Fang

    2017-03-01

    Objective The aim of this study was to develop a novel immersed multilayer biodegradable ureteral stent with reformed biodegradation and evaluate it in vitro. Methods Poly(glycolic-co-lactic acid) (PGLA), microsphere zein and BaSO4 were employed to produce a multilayer biodegradable stent using immersion technology. Tests of the biodegradable stents and conventional control stents were conducted in human urine in vitro to evaluate the biodegradable properties. The biocompatibility was assessed by the morphology and proliferation of urine-derived cells cultured with extracted media from the biodegradable stent and a latex material positive control. Results An immersed multilayer biodegradable stent was successfully produced. It began to degrade in week 2 and was fully degraded by week 4. The mass loss ratio in the first 2 weeks was low (approximately 10.0% at 1 week, 20.0% at 2 weeks) and increased after 3 weeks (approximately 70%) to the end of testing. During the first 2 weeks, the radial compression load performances of the biodegradable stents were better than those of the control stents with statistically significant differences ( p = 0.00, p = 0.01) and the tensile strengths were lower in the biodegradable stents than those in the control stents throughout the experiment. SEM showed that the stents degraded layer by layer from the outer to the inner wall. The influences on the cells of extracted medium from the biodegradable stents were morphologically slight and lower than 10% in relative growth rates. Conclusions This preliminary study demonstrates that the immersed multilayer biodegradable ureteral stent has good radial compression and biocompatible performance and can be degraded in vitro within 4 weeks in a moderate manner.

  14. Biodegradation of the Pyrethroid Pesticide Esfenvalerate by Marine-Derived Fungi.

    PubMed

    Birolli, Willian G; Alvarenga, Natália; Seleghim, Mirna H R; Porto, André L M

    2016-08-01

    Esfenvalerate biodegradation by marine-derived fungi is reported here. Esfenvalerate (S,S-fenvalerate) and its main metabolites [3-phenoxybenzaldehyde (PBAld), 3-phenoxybenzoic acid (PBAc), 3-phenoxybenzyl alcohol (PBAlc), and 2-(4-chlorophenyl)-3-methylbutyric acid (CLAc)] were quantitatively analyzed by a validated method in triplicate experiments. All the strains (Penicillium raistrickii CBMAI 931, Aspergillus sydowii CBMAI 935, Cladosporium sp. CBMAI 1237, Microsphaeropsis sp. CBMAI 1675, Acremonium sp. CBMAI 1676, Westerdykella sp. CBMAI 1679, and Cladosporium sp. CBMAI 1678) were able to degrade esfenvalerate, however, with different efficiencies. Initially, 100 mg L(-1) esfenvalerate (Sumidan 150SC) was added to each culture in 3 % malt liquid medium. Residual esfenvalerate (64.8-95.2 mg L(-1)) and the concentrations of PBAc (0.5-7.4 mg L(-1)), ClAc (0.1-7.5 mg L(-1)), and PBAlc (0.2 mg L(-1)) were determined after 14 days. In experiments after 7, 14, 21, and 28 days of biodegradation with the three most efficient strains, increasing concentrations of the toxic compounds PBAc (2.7-16.6 mg L(-1), after 28 days) and CLAc (6.6-13.4 mg L(-1), after 28 days) were observed. A biodegradation pathway was proposed, based on HPLC-ToF results. The biodegradation pathway includes PBAld, PBAc, PBAlc, ClAc, 2-hydroxy-2-(3-phenoxyphenyl)acetonitrile, 3-(hydroxyphenoxy)benzoic acid, and methyl 3-phenoxy benzoate. Marine-derived fungi were able to biodegrade esfenvalerate in a commercial formulation and showed their potential for future bioremediation studies in contaminated soils and water bodies.

  15. Evaluation of biodegradation-promoting additives for plastics.

    PubMed

    Selke, Susan; Auras, Rafael; Nguyen, Tuan Anh; Castro Aguirre, Edgar; Cheruvathur, Rijosh; Liu, Yan

    2015-03-17

    Biodegradation-promoting additives for polymers are increasingly being used around the world with the claim that they effectively render commercial polymers biodegradable. However, there is a lot of uncertainty about their effectiveness in degrading polymers in different environments. In this study, we evaluated the effect of biodegradation-promoting additives on the biodegradation of polyethylene (PE) and polyethylene terephthalate (PET). Biodegradation was evaluated in compost, anaerobic digestion, and soil burial environments. None of the five different additives tested significantly increased biodegradation in any of these environments. Thus, no evidence was found that these additives promote and/or enhance biodegradation of PE or PET polymers. So, anaerobic and aerobic biodegradation are not recommended as feasible disposal routes for nonbiodegradable plastics containing any of the five tested biodegradation-promoting additives.

  16. Alcoholism and alcohol drinking habits predicted from alcohol dehydrogenase genes.

    PubMed

    Tolstrup, Janne Schurmann; Nordestgaard, Børge Grønne; Rasmussen, Søren; Tybjaerg-Hansen, Anne; Grønbaek, Morten

    2008-06-01

    Alcohol drinking habits and alcoholism are partly genetically determined. Alcohol is degraded primarily by alcohol dehydrogenase (ADH) wherein genetic variation that affects the rate of alcohol degradation is found in ADH1B and ADH1C. It is biologically plausible that these variations may be associated with alcohol drinking habits and alcoholism. By genotyping 9080 white men and women from the general population, we found that men and women with ADH1B slow vs fast alcohol degradation drank more alcohol and had a higher risk of everyday drinking, heavy drinking, excessive drinking and of alcoholism. For example, the weekly alcohol intake was 9.8 drinks (95% confidence interval (CI): 9.1-11) among men with the ADH1B.1/1 genotype compared to 7.5 drinks (95% CI: 6.4-8.7) among men with the ADH1B.1/2 genotype, and the odds ratio (OR) for heavy drinking was 3.1 (95% CI: 1.7-5.7) among men with the ADH1B.1/1 genotype compared to men with the ADH1B.1/2 genotype. Furthermore, individuals with ADH1C slow vs fast alcohol degradation had a higher risk of heavy and excessive drinking. For example, the OR for heavy drinking was 1.4 (95% CI: 1.1-1.8) among men with the ADH1C.1/2 genotype and 1.4 (95% CI: 1.0-1.9) among men with the ADH1B.2/2 genotype, compared with men with the ADH1C.1/1 genotype. Results for ADH1B and ADH1C genotypes among men and women were similar. Finally, because slow ADH1B alcohol degradation is found in more than 90% of the white population compared to less than 10% of East Asians, the population attributable risk of heavy drinking and alcoholism by ADH1B.1/1 genotype was 67 and 62% among the white population compared with 9 and 24% among the East Asian population.

  17. Aerobic biodegradation of organic compounds in hydraulic fracturing fluids.

    PubMed

    Kekacs, Daniel; Drollette, Brian D; Brooker, Michael; Plata, Desiree L; Mouser, Paula J

    2015-07-01

    Little is known of the attenuation of chemical mixtures created for hydraulic fracturing within the natural environment. A synthetic hydraulic fracturing fluid was developed from disclosed industry formulas and produced for laboratory experiments using commercial additives in use by Marcellus shale field crews. The experiments employed an internationally accepted standard method (OECD 301A) to evaluate aerobic biodegradation potential of the fluid mixture by monitoring the removal of dissolved organic carbon (DOC) from an aqueous solution by activated sludge and lake water microbial consortia for two substrate concentrations and four salinities. Microbial degradation removed from 57 % to more than 90 % of added DOC within 6.5 days, with higher removal efficiency at more dilute concentrations and little difference in overall removal extent between sludge and lake microbe treatments. The alcohols isopropanol and octanol were degraded to levels below detection limits while the solvent acetone accumulated in biological treatments through time. Salinity concentrations of 40 g/L or more completely inhibited degradation during the first 6.5 days of incubation with the synthetic hydraulic fracturing fluid even though communities were pre-acclimated to salt. Initially diverse microbial communities became dominated by 16S rRNA sequences affiliated with Pseudomonas and other Pseudomonadaceae after incubation with the synthetic fracturing fluid, taxa which may be involved in acetone production. These data expand our understanding of constraints on the biodegradation potential of organic compounds in hydraulic fracturing fluids under aerobic conditions in the event that they are accidentally released to surface waters and shallow soils.

  18. Hydrocarbon Biodegradation in Hypersaline Environments

    PubMed Central

    Ward, David M.; Brock, T. D.

    1978-01-01

    When mineral oil, hexadecane, and glutamate were added to natural samples of varying salinity (3.3 to 28.4%) from salt evaporation ponds and Great Salt Lake, Utah, rates of metabolism of these compounds decreased as salinity increased. Rate limitations did not appear to relate to low oxygen levels or to the availability of organic nutrients. Some oxidation of l-[U-14C]glutamic acid occurred even at extreme salinities, whereas oxidation of [1-14C]hexadecane was too low to be detected. Gas chromatographic examination of hexane-soluble components of tar samples from natural seeps at Rozel Point in Great Salt Lake demonstrated no evidence of biological oxidation of isoprenoid alkanes subject to degradation in normal environments. Some hexane-soluble components of the same tar were altered by incubation in a low-salinity enrichment culture inoculated with garden soil. Attempts to enrich for microorganisms in saline waters able to use mineral oil as a sole source of carbon and energy were successful below, but not above, about 20% salinity. This study strongly suggests a general reduction of metabolic rate at extreme salinities and raises doubt about the biodegradation of hydrocarbons in hypersaline environments. PMID:16345276

  19. Biomechanical Challenges to Polymeric Biodegradable Stents.

    PubMed

    Soares, Joao S; Moore, James E

    2016-02-01

    Biodegradable implants have demonstrated clinical success in simple applications (e.g., absorbable sutures) and have shown great potential in many other areas of interventional medicine, such as localized drug delivery, engineered tissue scaffolding, and structural implants. For endovascular stenting and musculoskeletal applications, they can serve as temporary mechanical support that provides a smooth stress-transfer from the degradable implant to the healing tissue. However, for more complex device geometries, in vivo environments, and evolving load-bearing functions, such as required for vascular stents, there are considerable challenges associated with the use of biodegradable materials. A biodegradable stent must restore blood flow and provide support for a predictable appropriate period to facilitate artery healing, and subsequently, fail safely and be absorbed in a controllable manner. Biodegradable polymers are typically weaker than metals currently employed to construct stents, so it is difficult to ensure sufficient strength to keep the artery open and alleviate symptoms acutely while keeping other design parameters within clinically acceptable ranges. These design challenges are serious, given the general lack of understanding of biodegradable polymer behavior and evolution in intimal operating conditions. The modus operandi is mainly empirical and relies heavily on trial-and-error methodologies burdened by difficult, resource-expensive, and time-consuming experiments. We are striving for theoretical advancements systematizing the empirical knowledge into rational frameworks that could be cast into in silico tools for simulation and product development optimization. These challenges are evident when one considers that there are no biodegradable stents on the US market despite more than 30 years of development efforts (and currently only a couple with CE mark). This review summarizes previous efforts at implementing biodegradable stents, discusses the

  20. Prediction of biodegradability from chemical structure: Modeling or ready biodegradation test data

    SciTech Connect

    Loonen, H.; Lindgren, F.; Hansen, B.

    1999-08-01

    Biodegradation data were collected and evaluated for 894 substances with widely varying chemical structures. All data were determined according to the Japanese Ministry of International Trade and Industry (MITI) I test protocol. The MITI I test is a screening test for ready biodegradability and has been described by Organization for Economic Cooperation and Development (OECD) test guideline 301 C and European Union (EU) test guideline C4F. The chemicals were characterized by a set of 127 predefined structural fragments. This data set was used to develop a model for the prediction of the biodegradability of chemicals under standardized OECD and EU ready biodegradation test conditions. Partial least squares (PLS) discriminant analysis was used for the model development. The model was evaluated by means of internal cross-validation and repeated external validation. The importance of various structural fragments and fragment interactions was investigated. The most important fragments include the presence of a long alkyl chain; hydroxy, ester, and acid groups (enhancing biodegradation); and the presence of one or more aromatic rings and halogen substituents (regarding biodegradation). More than 85% of the model predictions were correct for using the complete data set. The not readily biodegradable predictions were slightly better than the readily biodegradable predictions (86 vs 84%). The average percentage of correct predictions from four external validation studies was 83%. Model optimization by including fragment interactions improve the model predicting capabilities to 89%. It can be concluded that the PLS model provides predictions of high reliability for a diverse range of chemical structures. The predictions conform to the concept of readily biodegradable (or not readily biodegradable) as defined by OECD and EU test guidelines.

  1. Alcoholism and reproduction.

    PubMed

    Heine, M W

    1981-01-01

    A brief overview of the reproductive capacities of both men and women in alcoholism is presented. A historical evaluation indicates a resurgence of interest in this area. The effect of chronic alcohol consumption on both male fertility and potency is reported in conjunction with alcohol-mediated effects on the female subject. Emphasis is placed on pharmacokinetics, metabolism and drinking behavior of the alcoholic female. The adverse actions of some therapeutic drugs and chronic alcohol consumption is discussed in relationship to fetal alcohol syndrome and the accompanied mental and somatic abnormalities.

  2. Alcohol and fuel production

    SciTech Connect

    Roth, E.R.

    1984-01-10

    Alcohol/water mixtures, such as those produced by fermentation of biomass material, are separated by extraction of alcohol with a solvent, comprising a higher aliphatic alcohol in major amount and an aliphatic hydrocarbon in minor amount, especially suited to such extraction and to subsequent removal. The solvent alcohol desirably has a branched chain, or the hydrocarbon an unsaturated bond, or both. Conventional distillation steps to concentrate alcohol and eliminate water are rendered unnecessary at a considerable reduction in heat energy requirement (usually met with fossil fuel). Optional addition of gasoline between the solvent extraction and solvent recovery steps not only aids the latter separation but produces alcohol already denatured for fuel use.

  3. Neurologic effects of alcoholism.

    PubMed Central

    Diamond, I; Messing, R O

    1994-01-01

    Alcoholism, a worldwide disorder, is the cause of a variety of neurologic disorders. In this article we discuss the cellular pathophysiology of ethanol addition and abuse as well as evidence supporting and refuting the role of inheritance in alcoholism. A genetic marker for alcoholism has not been identified, but neurophysiologic studies may be promising. Some neurologic disorders related to longterm alcoholism are due predominantly to inadequate nutrition (the thiamine deficiency that causes Wernicke's encephalopathy), but others appear to involve the neurotoxicity of ethanol on brain (alcohol withdrawal syndrome and dementia) and peripheral nerves (alcoholic neuropathy and myopathy). Images PMID:7975567

  4. Fetal Alcohol Spectrum Disorders (FASDs): Alcohol Use Quiz

    MedlinePlus

    ... this page: About CDC.gov . FASD Homepage Facts Secondary Conditions Videos Alcohol Use in Pregnancy Questions & Answers Quiz Alcohol Screening & Brief Intervention Diagnosis Treatments Data & Statistics Alcohol Consumption Rates Research & Tracking Monitoring Alcohol ...

  5. Fetal Alcohol Spectrum Disorders.

    PubMed

    Williams, Janet F; Smith, Vincent C

    2015-11-01

    Prenatal exposure to alcohol can damage the developing fetus and is the leading preventable cause of birth defects and intellectual and neurodevelopmental disabilities. In 1973, fetal alcohol syndrome was first described as a specific cluster of birth defects resulting from alcohol exposure in utero. Subsequently, research unequivocally revealed that prenatal alcohol exposure causes a broad range of adverse developmental effects. Fetal alcohol spectrum disorder (FASD) is the general term that encompasses the range of adverse effects associated with prenatal alcohol exposure. The diagnostic criteria for fetal alcohol syndrome are specific, and comprehensive efforts are ongoing to establish definitive criteria for diagnosing the other FASDs. A large and growing body of research has led to evidence-based FASD education of professionals and the public, broader prevention initiatives, and recommended treatment approaches based on the following premises:▪ Alcohol-related birth defects and developmental disabilities are completely preventable when pregnant women abstain from alcohol use.▪ Neurocognitive and behavioral problems resulting from prenatal alcohol exposure are lifelong.▪ Early recognition, diagnosis, and therapy for any condition along the FASD continuum can result in improved outcomes.▪ During pregnancy:◦no amount of alcohol intake should be considered safe;◦there is no safe trimester to drink alcohol;◦all forms of alcohol, such as beer, wine, and liquor, pose similar risk; and◦binge drinking poses dose-related risk to the developing fetus.

  6. Biodegradable lignin/polyolefin composite films

    SciTech Connect

    Kosikova, B.; Demjanova, V.; Mikulasova, M.; Lora, J.H.

    1993-12-31

    From the view point of environmental protection, the plastic wastes, especially from packing materials, represent a potential waste problem. Various approaches were examined to develop partially or completely biodegradable plastics. New type of partially biodegradable polyolefins was prepared by blending of polypropylene with lignin, which was recovered in the ALCELL process, an organosolv pulping process that uses ethanol-water as the delignifying agent. Films of blends with up to 10% wt ALCELL lignin, prepared in absence of commercial stabilizers, had acceptable mechanical strengths. The effect of lignin on biodegradability of the composite films was examined by comparison of behaviour of both pure and lignin containing films during treatment with fungus Phanerochaete chrysosporium. It was found that this fungus is able to grow and to produce lignolytic enzymes in the presence of the films containing lignin. Biodegradation of lignin in the composite film was confirmed by the releasing of lignin fragments into the extracellular fluid. Because of measurement of mechanical properties offers a mean of direct estimation of polymer degradation, the degree of biodegradation of the films tested was followed by monitoring of elongation at break. The changes of break at elongation in the course of enzymatic treatment revealed that the lignin/PP composite films are potentially environmentally nonpersisting. The micrographs of the lignin containing films obtained by scanning electron microscopy show the significant changes of the film surface upon degradation with Phanerochaete chrysosporium in contrast to unchanged lignin free film.

  7. Biodegradable compounds: Rheological, mechanical and thermal properties

    NASA Astrophysics Data System (ADS)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  8. Alcohol Use and Older Adults

    MedlinePlus

    ... version of this page please turn Javascript on. Alcohol Use and Older Adults Alcohol and Aging Adults of any age can have ... Escape (Esc) button on your keyboard.) What Is Alcohol? Alcohol, also known as ethanol, is a chemical ...

  9. Fetal Alcohol Spectrum Disorders

    MedlinePlus

    ... Daily life skills, such as feeding and bathing Fetal alcohol syndrome is the most serious type of FASD. People with fetal alcohol syndrome have facial abnormalities, including wide-set and narrow ...

  10. Children of Alcoholics.

    ERIC Educational Resources Information Center

    Chafetz, Morris E.

    1979-01-01

    It is estimated that 29 million American children have alcoholic parents. The author documents the unstable environment and psychological consequences suffered by these children, who are at great risk to become alcoholics themselves. (Editor)

  11. Fetal alcohol syndrome

    MedlinePlus

    ... resources for information on alcoholism: Alcoholics Anonymous -- www.aa.org Al-Anon Family Groups -- www.al-anon. ... exposures to the fetus. In: Martin RJ, Fanaroff AA, Walsh MC, eds. Fanaroff and Martin's Neonatal-Perinatal ...

  12. Alcohol Use Screening

    MedlinePlus

    ... Centers Mental Health Medical Library Alcohol Use Screening (AUDIT-C) - Instructions The following questions are a screening ... is also text-only version . Alcohol Use Screening (AUDIT-C) - Manual Instructions The following questions are a ...

  13. Epidemiology of Alcoholism.

    ERIC Educational Resources Information Center

    Helzer, John E.

    1987-01-01

    Reviews the application of epidemiology to alcoholism. Discusses measurement and diagnostic issues and reviews studies of the prevalence of alcoholism, its risk factors, and the contributions of epidemiology to our knowledge of treatment and prevention. (Author/KS)

  14. Women and Alcohol

    MedlinePlus

    ... turn JavaScript on. Feature: Rethinking Drinking Women and Alcohol Past Issues / Spring 2014 Table of Contents Women react differently than men to alcohol and face higher risks from it. Pound for ...

  15. Myths about drinking alcohol

    MedlinePlus

    ... gov/ency/patientinstructions/000856.htm Myths about drinking alcohol To use the sharing features on this page, ... We know much more about the effects of alcohol today than in the past. Yet, myths remain ...

  16. Benzyl Alcohol Topical

    MedlinePlus

    Benzyl alcohol lotion is used to treat head lice (small insects that attach themselves to the skin) in adults ... children less than 6 months of age. Benzyl alcohol is in a class of medications called pediculicides. ...

  17. Translational Studies of Alcoholism

    PubMed Central

    Zahr, Natalie M.; Sullivan, Edith V.

    2008-01-01

    Human studies are necessary to identify and classify the brain systems predisposing individuals to develop alcohol use disorders and those modified by alcohol, while animal models of alcoholism are essential for a mechanistic understanding of how chronic voluntary alcohol consumption becomes compulsive, how brain systems become damaged, and how damage resolves. Our current knowledge of the neuroscience of alcohol dependence has evolved from the interchange of information gathered from both human alcoholics and animal models of alcoholism. Together, studies in humans and animal models have provided support for the involvement of specific brain structures over the course of alcohol addiction, including the prefrontal cortex, basal ganglia, cerebellum, amygdala, hippocampus, and the hypothalamic–pituitary–adrenal axis. PMID:20041042

  18. Evaluating the primary and ready biodegradability of dianilinodithiophosphoric acid.

    PubMed

    Lin, Weixiong; Sun, Shuiyu; Xu, Pingting; Dai, Yongkang; Ren, Jie

    2016-04-01

    Dianilinodithiophosphoric acid (DDA) is widely used as sulfide mineral flotation collector in China. It is necessary to investigate the biodegradability of DDA to provide the fundamental knowledge to assess the environmental fate in the risk assessment of DDA and to design and operate the DDA flotation wastewater biological treatment plant. In the present study, the primary and ready aerobic biodegradations of DDA were studied and the primary biodegradation kinetic model of DDA was developed. The results show that DDA displays a good primary biodegradability and its biodegradation ratio reaches 99.8 % in 7 days. In contrast, DDA is not easily ready biodegradable; hence, it is a partially biodegradable organic compound. The primary aerobic biodegradation kinetics can be described using the first-order reaction kinetics equation: C = 19.72191e(-0.01513t).

  19. Biodegradability of organic nanoparticles in the aqueous environment.

    PubMed

    Kümmerer, Klaus; Menz, Jakob; Schubert, Thomas; Thielemans, Wim

    2011-03-01

    Synthetic nanoparticles have already been detected in the aquatic environment. Therefore, knowledge on their biodegradability is of utmost importance for risk assessment but such information is currently not available. Therefore, the biodegradability of fullerenes, single, double, multi-walled as well as COOH functionalized carbon nanotubes and cellulose and starch nanocrystals in aqueous environment has been investigated according to OECD standards. The biodegradability of starch and cellulose nanoparticles was also compared with the biodegradability of their macroscopic counterparts. Fullerenes and all carbon nanotubes did not biodegrade at all, while starch and cellulose nanoparticles biodegrade to similar levels as their macroscopic counterparts. However, neither comfortably met the criterion for ready biodegradability (60% after 28 days). The cellulose and starch nanoparticles were also found to degrade faster than their macroscopic counterparts due to their higher surface area. These findings are the first report of biodegradability of organic nanoparticles in the aquatic environment, an important accumulation environment for manmade compounds.

  20. Alcohol advertising and alcohol consumption by adolescents.

    PubMed

    Saffer, Henry; Dave, Dhaval

    2006-06-01

    This study investigates the effects of alcohol advertising on adolescent alcohol consumption. The theory of an industry response function and evidence from prior studies indicate the importance of maximizing the variance in advertising measures. Monitoring the Future (MTF) and National Longitudinal Survey of Youth 1997 (NLSY97) data are augmented with alcohol advertising, originating on the market level, for five media. The large sample of the MTF allows estimation of race and gender-specific models. The longitudinal nature of the NLSY97 allows controls for unobserved heterogeneity with state-level and individual fixed effects. Price and advertising effects are generally larger for females relative to males. Controls for individual heterogeneity yield larger advertising effects, implying that the MTF results may understate the effects of alcohol advertising. Results from the NLSY97 suggest that a 28% reduction in alcohol advertising would reduce adolescent monthly alcohol participation from 25% to between 24 and 21%. For binge participation, the reduction would be from 12% to between 11 and 8%. The past month price-participation elasticity is estimated at -0.26, consistent with prior studies. The results show that reduction of alcohol advertising can produce a modest decline in adolescent alcohol consumption, though effects may vary by race and gender.

  1. Introduction of Environmentally Degradable Parameters to Evaluate the Biodegradability of Biodegradable Polymers

    PubMed Central

    Yang, Chao; Song, Cunjiang; Geng, Weitao; Li, Qiang; Wang, Yuanyuan; Kong, Meimei; Wang, Shufang

    2012-01-01

    Environmentally Degradable Parameter (EdK) is of importance in the describing of biodegradability of environmentally biodegradable polymers (BDPs). In this study, a concept EdK was introduced. A test procedure of using the ISO 14852 method and detecting the evolved carbon dioxide as an analytical parameter was developed, and the calculated EdK was used as an indicator for the ultimate biodegradability of materials. Starch and polyethylene used as reference materials were defined as the EdK values of 100 and 0, respectively. Natural soil samples were inoculated into bioreactors, followed by determining the rates of biodegradation of the reference materials and 15 commercial BDPs over a 2-week test period. Finally, a formula was deduced to calculate the value of EdK for each material. The EdK values of the tested materials have a positive correlation to their biodegradation rates in the simulated soil environment, and they indicated the relative biodegradation rate of each material among all the tested materials. Therefore, the EdK was shown to be a reliable indicator for quantitatively evaluating the potential biodegradability of BDPs in the natural environment. PMID:22675455

  2. Distillation for alcohol

    SciTech Connect

    Kawase, T.; Sawai, K.

    1983-02-22

    A new distillation equipment for alcohol which consists mainly of a brief concentrating column a, a concentrating column b, a compressor C to compress alcohol vapor generated in column B and water evaporator D heated by the compressed alcohol vapor is developed and this especially fits for a distillation source of a glue like solution obtained by alcohol fermentation because steam generated in the water evaporator D is directly blown into the solution in the concentrating column A.

  3. Alcohol and fuel production

    SciTech Connect

    Roth, E.R.

    1981-12-22

    Alcohol/water mixtures, such as those produced by fermentation of biomass material, are separated by extraction of alcohol with a solvent especially suited to such extraction and to subsequent removal. Conventional distillation steps to concentrate alcohol and eliminate water are rendered unnecessary at a considerable reduction in heat energy requirement (Usually met with fossil fuel). Addition of gasoline between the solvent extraction and solvent recovery steps not only aids the latter separation but produces alcohol already denatured for fuel use.

  4. Television: Alcohol's Vast Adland.

    ERIC Educational Resources Information Center

    2002

    Concern about how much television alcohol advertising reaches underage youth and how the advertising influences their attitudes and decisions about alcohol use has been widespread for many years. Lacking in the policy debate has been solid, reliable information about the extent of youth exposure to television alcohol advertising. To address this…

  5. Alcohol and the law.

    PubMed

    Karasov, Ariela O; Ostacher, Michael J

    2014-01-01

    Society has had an interest in controlling the production, distribution, and use of alcohol for millennia. The use of alcohol has always had consequences, be they positive or negative, and the role of government in the regulation of alcohol is now universal. This is accomplished at several levels, first through controls on production, importation, distribution, and use of alcoholic beverages, and second, through criminal laws, the aim of which is to address the behavior of users themselves. A number of interventions and policies reduce alcohol-related consequences to society by regulating alcohol pricing, targeting alcohol-impaired driving, and limiting alcohol availability. The legal system defines criminal responsibility in the context of alcohol use, as an enormous percentage of violent crime and motor death is associated with alcohol intoxication. In recent years, recovery-oriented policies have aimed to expand social supports for recovery and to improve access to treatment for substance use disorders within the criminal justice system. The Affordable Care Act, also know as "ObamaCare," made substantial changes to access to substance abuse treatment by mandating that health insurance include services for substance use disorders comparable to coverage for medical and surgical treatments. Rather than a simplified "war on drugs" approach, there appears to be an increasing emphasis on evidence-based policy development that approaches alcohol use disorders with hope for treatment and prevention. This chapter focuses on alcohol and the law in the United States.

  6. Alcohol and Family Violence.

    ERIC Educational Resources Information Center

    Covington, Stephanie S.

    There is growing acknowledgement of the association between family violence and alcohol use. A study was conducted to examine the role that abuse plays in the lives of women and to investigate the relationship between alcohol and violence. Data were collected from 35 recovering female alcoholics and 35 nonalcoholic women on their sexual experience…

  7. Alcoholism's Hidden Curriculum.

    ERIC Educational Resources Information Center

    Gress, James R.

    1988-01-01

    Discusses children of alcoholics as victims of fetal alcohol syndrome, family violence, retarded social development, and severe emotional scars. These children bring family roles to school that allow survival in the alcoholic home but are dysfunctional outside it. Educators can take certain steps to address these students' problems. Includes six…

  8. Biological Vulnerability to Alcoholism.

    ERIC Educational Resources Information Center

    Schuckit, Marc A.

    1987-01-01

    Reviews the role of biological factors in the risk for alcoholism. Notes the importance of the definition of primary alcoholism and highlights data indicating that this disorder is genetically influenced. In studies of men at high risk for the future development of alcoholism, vulnerability shows up in reactions to ethanol brain wave amplitude and…

  9. Drugs, Alcohol and HIV

    MedlinePlus

    ... and drugs can do to your overall health. Drugs and Alcohol: Effects on your immune system Drinking too much alcohol ... getting help and finding the treatment you need. Drugs and Alcohol: ... on short- and long-term effects of drinking, with specific information on people who ...

  10. Alcohol and Aggression.

    ERIC Educational Resources Information Center

    Gustafson, Roland

    1994-01-01

    Reviews the acute effects of alcohol on aggressive responding. From experimental studies that use human subjects, it is concluded that a moderate dose of alcohol does not increase aggression if subjects are unprovoked. Under provocative situations, aggression is increased as a function of alcohol intoxication, provided that subjects are restricted…

  11. Alcoholism and Lesbians

    ERIC Educational Resources Information Center

    Gedro, Julie

    2014-01-01

    This chapter explores the issues involved in the relationship between lesbianism and alcoholism. It examines the constellation of health and related problems created by alcoholism, and it critically interrogates the societal factors that contribute to the disproportionately high rates of alcoholism among lesbians by exploring the antecedents and…

  12. Biodegradable Hybrid Stomatocyte Nanomotors for Drug Delivery

    PubMed Central

    2017-01-01

    We report the self-assembly of a biodegradable platinum nanoparticle-loaded stomatocyte nanomotor containing both PEG-b-PCL and PEG-b-PS as a potential candidate for anticancer drug delivery. Well-defined stomatocyte structures could be formed even after incorporation of 50% PEG-b-PCL polymer. Demixing of the two polymers was expected at high percentage of semicrystalline poly(ε-caprolactone) (PCL), resulting in PCL domain formation onto the membrane due to different properties of two polymers. The biodegradable motor system was further shown to move directionally with speeds up to 39 μm/s by converting chemical fuel, hydrogen peroxide, into mechanical motion as well as rapidly delivering the drug to the targeted cancer cell. Uptake by cancer cells and fast doxorubicin drug release was demonstrated during the degradation of the motor system. Such biodegradable nanomotors provide a convenient and efficient platform for the delivery and controlled release of therapeutic drugs. PMID:28187254

  13. Biodegradable nanoparticles for gene therapy technology

    NASA Astrophysics Data System (ADS)

    Hosseinkhani, Hossein; He, Wen-Jie; Chiang, Chiao-Hsi; Hong, Po-Da; Yu, Dah-Shyong; Domb, Abraham J.; Ou, Keng-Liang

    2013-07-01

    Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes.

  14. Novel biodegradable nanocarriers for enhanced drug delivery.

    PubMed

    Gagliardi, Mariacristina

    2016-12-01

    With the refinement of functional properties, the interest around biodegradable materials, in biorelated applications and, in particular, in their use as controlled drug-delivery systems, increased in the last decades. Biodegradable materials are an ideal platform to obtain nanoparticles for spatiotemporal controlled drug delivery for the in vivo administration, thanks to their biocompatibility, functionalizability, the control exerted on delivery rates and the complete degradation. Their application in systems for cancer treatment, brain and cardiovascular diseases is already a consolidated practice in research, while the bench-to-bedside translation is still late. This review aims at summarizing reported applications of biodegradable materials to obtain drug-delivery nanoparticles in the last few years, giving a complete overview of pros and cons related to degradable nanomedicaments.

  15. Biodegradable Hybrid Stomatocyte Nanomotors for Drug Delivery.

    PubMed

    Tu, Yingfeng; Peng, Fei; André, Alain A M; Men, Yongjun; Srinivas, Mangala; Wilson, Daniela A

    2017-02-28

    We report the self-assembly of a biodegradable platinum nanoparticle-loaded stomatocyte nanomotor containing both PEG-b-PCL and PEG-b-PS as a potential candidate for anticancer drug delivery. Well-defined stomatocyte structures could be formed even after incorporation of 50% PEG-b-PCL polymer. Demixing of the two polymers was expected at high percentage of semicrystalline poly(ε-caprolactone) (PCL), resulting in PCL domain formation onto the membrane due to different properties of two polymers. The biodegradable motor system was further shown to move directionally with speeds up to 39 μm/s by converting chemical fuel, hydrogen peroxide, into mechanical motion as well as rapidly delivering the drug to the targeted cancer cell. Uptake by cancer cells and fast doxorubicin drug release was demonstrated during the degradation of the motor system. Such biodegradable nanomotors provide a convenient and efficient platform for the delivery and controlled release of therapeutic drugs.

  16. Experimental studies on waste paper pulp biodegradation.

    PubMed

    Sharma, R; Sharma, D; Rao, K S; Jain, R C

    2002-07-01

    In continuation of their studies on Biodegradation of cellulosic waste materials, the authors have presented their experimental data on biodegradation on waste paper pulp. Greater efficiency in the cow dung and M3 culture experimental setups have been pointed out and discussed. Necessity of detailed data evaluation of temperature, pH, dry weight, cellulose, protein, carbohydrate, Nitrate, Phosphate & Potassium levels is suggested. Derivation of %, absolute and increase/decrease % of BOO, COD and VS have been pointed out for the first time in solid waste Biodegradation. Further data evaluation and derivation of critical reaction rate kinetics have been recommended for further studies in solid waste-degradation to achieve quicker Bioconversion of cellulosic wastes into compost.

  17. Biodegradable Polymers and Stem Cells for Bioprinting.

    PubMed

    Lei, Meijuan; Wang, Xiaohong

    2016-04-29

    It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

  18. Amino alcohol-based degradable poly(ester amide) elastomers

    PubMed Central

    Bettinger, Christopher J.; Bruggeman, Joost P.; Borenstein, Jeffrey T.; Langer, Robert S.

    2009-01-01

    Currently available synthetic biodegradable elastomers are primarily composed of crosslinked aliphatic polyesters, which suffer from deficiencies including (1) high crosslink densities, which results in exceedingly high stiffness, (2) rapid degradation upon implantation, or (3) limited chemical moieties for chemical modification. Herein, we have developed poly(1,3-diamino-2-hydroxypropane-co-polyol sebacate)s, a new class of synthetic, biodegradable elastomeric poly(ester amide)s composed of crosslinked networks based on an amino alcohol. These crosslinked networks feature tensile Young’s modulus on the order of 1 MPa and reversable elongations up to 92%. These polymers exhibit in vitro and in vivo biocompatibility. These polymers have projected degradation half-lives up to 20 months in vivo. PMID:18295329

  19. A Biodegradable and Proteolipid Bone Repair Composite,

    DTIC Science & Technology

    1983-11-10

    hydroxy acids known as polygloclic acid (PGA) and polylactic acid (PLA) were initially formulated and described as biodegradable suture materials.8𔄃 ,10...DE, Hunsuck EE, "Tissue Reaction to the Biodegradable Polylactic Acid Suture," Oral Surg, 31:134-139, 1971. 9. Frazza E, Schmitt E, "The Value of...Absorbable Suture," J Biomed Mater Res, 1:43-58, 1971. 10. Kulkarni RK, Paul KC, Neuman C, and Leonard F, " Polylactic Acid for Surgical Implants," Arch

  20. Biodegradable containers from green waste materials

    NASA Astrophysics Data System (ADS)

    Sartore, Luciana; Schettini, Evelia; Pandini, Stefano; Bignotti, Fabio; Vox, Giuliano; D'Amore, Alberto

    2016-05-01

    Novel biodegradable polymeric materials based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene glycol) diglycidyl ether (PEG) or epoxidized soybean oil (ESO) were obtained and their physico-chemical properties and mechanical behaviour were evaluated. Different processing conditions and the introduction of fillers of natural origin, as saw dust and wood flour, were used to tailor the mechanical properties and the environmental durability of the product. The biodegradable products, which are almost completely manufactured from renewable-based raw materials, look promising for several applications, particularly in agriculture for the additional fertilizing action of PH or in packaging.

  1. Injectable biodegradable materials for orthopedic tissue engineering.

    PubMed

    Temenoff, J S; Mikos, A G

    2000-12-01

    The large number of orthopedic procedures performed each year, including many performed arthroscopically, have led to great interest in injectable biodegradable materials for regeneration of bone and cartilage. A variety of materials have been developed for these applications, including ceramics, naturally derived substances and synthetic polymers. These materials demonstrate overall biocompatibility and appropriate mechanical properties, as well as promote tissue formation, thus providing an important step towards minimally invasive orthopedic procedures. This review provides a comparison of these materials based on mechanical properties, biocompatibility and regeneration efficacy. Advantages and disadvantages of each material are explained and design criteria for injectable biodegradable systems are provided.

  2. Comparative study on the biodegradation and biocompatibility of silicate bioceramic coatings on biodegradable magnesium alloy as biodegradable biomaterial

    NASA Astrophysics Data System (ADS)

    Razavi, M.; Fathi, M. H.; Savabi, O.; Razavi, S. M.; Hashemibeni, B.; Yazdimamaghani, M.; Vashaee, D.; Tayebi, L.

    2014-03-01

    Many clinical cases as well as in vivo and in vitro assessments have demonstrated that magnesium alloys possess good biocompatibility. Unfortunately, magnesium and its alloys degrade too quickly in physiological media. In order to improve the biodegradation resistance and biocompatibility of a biodegradable magnesium alloy, we have prepared three types of coating include diopside (CaMgSi2O6), akermanite (Ca2MgSi2O6) and bredigite (Ca7MgSi4O16) coating on AZ91 magnesium alloy through a micro-arc oxidation (MAO) and electrophoretic deposition (EPD) method. In this research, the biodegradation and biocompatibility behavior of samples were evaluated in vitro and in vivo. The in vitro analysis was performed by cytocompatibility and MTT-assay and the in vivo test was conducted on the implantation of samples in the greater trochanter of adult rabbits. The results showed that diopside coating has the best bone regeneration and bredigite has the best biodegradation resistance compared to others.

  3. Migration of BTEX and Biodegradation in Shallow Underground Water through Fuel Leak Simulation.

    PubMed

    Cheng, Yaping; Chen, Yudao; Jiang, Yaping; Jiang, Lingzhi; Sun, Liqun; Li, Liuyue; Huang, Junyu

    2016-01-01

    To provide more reasonable references for remedying underground water, fuel leak was simulated by establishing an experimental model of a porous-aquifer sand tank with the same size as that of the actual tank and by monitoring the underground water. In the tank, traditional gasoline and ethyl alcohol gasoline were poured. This study was conducted to achieve better understanding of the migration and distribution of benzene, toluene, ethyl benzene, and xylene (BTEX), which are major pollutants in the underground water. Experimental results showed that, compared with conventional gasoline, the content peak of BTEX in the mixture of ethyl alcohol gasoline appeared later; BTEX migrated along the water flow direction horizontally and presented different pollution halos; BTEX also exhibited the highest content level at 45 cm depth; however, its content declined at the 30 and 15 cm depths vertically because of the vertical dispersion effect; the rise of underground water level increased the BTEX content, and the attenuation of BTEX content in underground water was related to the biodegradation in the sand tank, which mainly included biodegradation with oxygen, nitrate, and sulfate.

  4. Migration of BTEX and Biodegradation in Shallow Underground Water through Fuel Leak Simulation

    PubMed Central

    2016-01-01

    To provide more reasonable references for remedying underground water, fuel leak was simulated by establishing an experimental model of a porous-aquifer sand tank with the same size as that of the actual tank and by monitoring the underground water. In the tank, traditional gasoline and ethyl alcohol gasoline were poured. This study was conducted to achieve better understanding of the migration and distribution of benzene, toluene, ethyl benzene, and xylene (BTEX), which are major pollutants in the underground water. Experimental results showed that, compared with conventional gasoline, the content peak of BTEX in the mixture of ethyl alcohol gasoline appeared later; BTEX migrated along the water flow direction horizontally and presented different pollution halos; BTEX also exhibited the highest content level at 45 cm depth; however, its content declined at the 30 and 15 cm depths vertically because of the vertical dispersion effect; the rise of underground water level increased the BTEX content, and the attenuation of BTEX content in underground water was related to the biodegradation in the sand tank, which mainly included biodegradation with oxygen, nitrate, and sulfate. PMID:27882327

  5. Biodegradation of atrazine by three transgenic grasses and alfalfa expressing a modified bacterial atrazine chlorohydrolase gene.

    PubMed

    Vail, Andrew W; Wang, Ping; Uefuji, Hirotaka; Samac, Deborah A; Vance, Carroll P; Wackett, Lawrence P; Sadowsky, Michael J

    2015-06-01

    The widespread use of atrazine and other s-triazine herbicides to control weeds in agricultural production fields has impacted surface and groundwater in the United States and elsewhere. We previously reported the cloning, sequencing, and expression of six genes involved in the atrazine biodegradation pathway of Pseudomonas sp. strain ADP, which is initiated by atzA, encoding atrazine chlorohydrolase. Here we explored the use of enhanced expression of a modified bacterial atrazine chlorohydrolase, p-AtzA, in transgenic grasses (tall fescue, perennial ryegrass, and switchgrass) and the legume alfalfa for the biodegradation of atrazine. Enhanced expression of p-AtzA was obtained by using combinations of the badnavirus promoter, the maize alcohol dehydrogenase first intron, and the maize ubiquitin promoter. For alfalfa, we used the first intron of the 5'-untranslated region tobacco alcohol dehydrogenase gene and the cassava vein mosaic virus promoter. Resistance of plants to atrazine in agar-based and hydroponic growth assays was correlated with in vivo levels of gene expression and atrazine degradation. The in planta expression of p-atzA enabled transgenic tall fescue to transform atrazine into hydroxyatrazine and other metabolites. Results of our studies highlight the potential use of transgenic plants for bioremediating atrazine in the environment.

  6. Genetics and alcoholism.

    PubMed

    Edenberg, Howard J; Foroud, Tatiana

    2013-08-01

    Alcohol is widely consumed; however, excessive use creates serious physical, psychological and social problems and contributes to the pathogenesis of many diseases. Alcohol use disorders (that is, alcohol dependence and alcohol abuse) are maladaptive patterns of excessive drinking that lead to serious problems. Abundant evidence indicates that alcohol dependence (alcoholism) is a complex genetic disease, with variations in a large number of genes affecting a person's risk of alcoholism. Some of these genes have been identified, including two genes involved in the metabolism of alcohol (ADH1B and ALDH2) that have the strongest known affects on the risk of alcoholism. Studies continue to reveal other genes in which variants affect the risk of alcoholism or related traits, including GABRA2, CHRM2, KCNJ6 and AUTS2. As more variants are analysed and studies are combined for meta-analysis to achieve increased sample sizes, an improved picture of the many genes and pathways that affect the risk of alcoholism will be possible.

  7. Alcohol and the Intestine

    PubMed Central

    Patel, Sheena; Behara, Rama; Swanson, Garth R.; Forsyth, Christopher B.; Voigt, Robin M.; Keshavarzian, Ali

    2015-01-01

    Alcohol abuse is a significant contributor to the global burden of disease and can lead to tissue damage and organ dysfunction in a subset of alcoholics. However, a subset of alcoholics without any of these predisposing factors can develop alcohol-mediated organ injury. The gastrointestinal tract (GI) could be an important source of inflammation in alcohol-mediated organ damage. The purpose of review was to evaluate mechanisms of alcohol-induced endotoxemia (including dysbiosis and gut leakiness), and highlight the predisposing factors for alcohol-induced dysbiosis and gut leakiness to endotoxins. Barriers, including immunologic, physical, and biochemical can regulate the passage of toxins into the portal and systemic circulation. In addition, a host of environmental interactions including those influenced by circadian rhythms can impact alcohol-induced organ pathology. There appears to be a role for therapeutic measures to mitigate alcohol-induced organ damage by normalizing intestinal dysbiosis and/or improving intestinal barrier integrity. Ultimately, the inflammatory process that drives progression into organ damage from alcohol appears to be multifactorial. Understanding the role of the intestine in the pathogenesis of alcoholic liver disease can pose further avenues for pathogenic and treatment approaches. PMID:26501334

  8. Alcoholic and non-alcoholic steatohepatitis

    PubMed Central

    Neuman, Manuela G.; French, Samuel W.; French, Barbara A.; Seitz, Helmut K.; Cohen, Lawrence B.; Mueller, Sebastian; Osna, Natalia A.; Kharbanda, Kusum K.; Seth, Devanshi; Bautista, Abraham; Thompson, Kyle J.; McKillop, Iain H.; Kirpich, Irina A.; McClain, Craig J.; Bataller, Ramon; Nanau, Radu M.; Voiculescu, Mihai; Opris, Mihai; Shen, Hong; Tillman, Brittany; Li, Jun; Liu, Hui; Thomas, Paul G.; Ganesan, Murali; Malnick, Steve

    2015-01-01

    This paper is based upon the “Charles Lieber Satellite Symposia” organized by Manuela G. Neuman at the Research Society on Alcoholism (RSA) Annual Meetings, 2013 and 2014. The present review includes pre-clinical, translational and clinical research that characterize alcoholic liver disease (ALD) and non-alcoholic steatohepatitis (NASH). In addition, a literature search in the discussed area was performed. Strong clinical and experimental evidence lead to recognition of the key toxic role of alcohol in the pathogenesis of ALD. The liver biopsy can confirm the etiology of NASH or alcoholic steatohepatitis (ASH) and assess structural alterations of cells, their organelles, as well as inflammatory activity. Three histological stages of ALD are simple steatosis, ASH, and chronic hepatitis with hepatic fibrosis or cirrhosis. These latter stages may also be associated with a number of cellular and histological changes, including the presence of Mallory's hyaline, megamitochondria, or perivenular and perisinusoidal fibrosis. Genetic polymorphisms of ethanol metabolizing enzymes such as cytochrome p450 (CYP) 2E1 activation may change the severity of ASH and NASH. Alcohol mediated hepatocarcinogenesis, immune response to alcohol in ASH, as well as the role of other risk factors such as its comorbidities with chronic viral hepatitis in the presence or absence of human deficiency virus are discussed. Dysregulation of hepatic methylation, as result of ethanol exposure, in hepatocytes transfected with hepatitis C virus (HCV), illustrates an impaired interferon signaling. The hepatotoxic effects of ethanol undermine the contribution of malnutrition to the liver injury. Dietary interventions such as micro and macronutrients, as well as changes to the microbiota are suggested. The clinical aspects of NASH, as part of metabolic syndrome in the aging population, are offered. The integrative symposia investigate different aspects of alcohol-induced liver damage and possible

  9. Alcoholic and non-alcoholic steatohepatitis.

    PubMed

    Neuman, Manuela G; French, Samuel W; French, Barbara A; Seitz, Helmut K; Cohen, Lawrence B; Mueller, Sebastian; Osna, Natalia A; Kharbanda, Kusum K; Seth, Devanshi; Bautista, Abraham; Thompson, Kyle J; McKillop, Iain H; Kirpich, Irina A; McClain, Craig J; Bataller, Ramon; Nanau, Radu M; Voiculescu, Mihai; Opris, Mihai; Shen, Hong; Tillman, Brittany; Li, Jun; Liu, Hui; Thomes, Paul G; Ganesan, Murali; Malnick, Steve

    2014-12-01

    This paper is based upon the "Charles Lieber Satellite Symposia" organized by Manuela G. Neuman at the Research Society on Alcoholism (RSA) Annual Meetings, 2013 and 2014. The present review includes pre-clinical, translational and clinical research that characterize alcoholic liver disease (ALD) and non-alcoholic steatohepatitis (NASH). In addition, a literature search in the discussed area was performed. Strong clinical and experimental evidence lead to recognition of the key toxic role of alcohol in the pathogenesis of ALD. The liver biopsy can confirm the etiology of NASH or alcoholic steatohepatitis (ASH) and assess structural alterations of cells, their organelles, as well as inflammatory activity. Three histological stages of ALD are simple steatosis, ASH, and chronic hepatitis with hepatic fibrosis or cirrhosis. These latter stages may also be associated with a number of cellular and histological changes, including the presence of Mallory's hyaline, megamitochondria, or perivenular and perisinusoidal fibrosis. Genetic polymorphisms of ethanol metabolizing enzymes such as cytochrome p450 (CYP) 2E1 activation may change the severity of ASH and NASH. Alcohol mediated hepatocarcinogenesis, immune response to alcohol in ASH, as well as the role of other risk factors such as its co-morbidities with chronic viral hepatitis in the presence or absence of human immunodeficiency virus are discussed. Dysregulation of hepatic methylation, as result of ethanol exposure, in hepatocytes transfected with hepatitis C virus (HCV), illustrates an impaired interferon signaling. The hepatotoxic effects of ethanol undermine the contribution of malnutrition to the liver injury. Dietary interventions such as micro and macronutrients, as well as changes to the microbiota are suggested. The clinical aspects of NASH, as part of metabolic syndrome in the aging population, are offered. The integrative symposia investigate different aspects of alcohol-induced liver damage and possible

  10. Alcohol disrupts sleep homeostasis.

    PubMed

    Thakkar, Mahesh M; Sharma, Rishi; Sahota, Pradeep

    2015-06-01

    Alcohol is a potent somnogen and one of the most commonly used "over the counter" sleep aids. In healthy non-alcoholics, acute alcohol decreases sleep latency, consolidates and increases the quality (delta power) and quantity of NREM sleep during the first half of the night. However, sleep is disrupted during the second half. Alcoholics, both during drinking periods and during abstinences, suffer from a multitude of sleep disruptions manifested by profound insomnia, excessive daytime sleepiness, and altered sleep architecture. Furthermore, subjective and objective indicators of sleep disturbances are predictors of relapse. Finally, within the USA, it is estimated that societal costs of alcohol-related sleep disorders exceeds $18 billion. Thus, although alcohol-associated sleep problems have significant economic and clinical consequences, very little is known about how and where alcohol acts to affect sleep. In this review, we have described our attempts to unravel the mechanism of alcohol-induced sleep disruptions. We have conducted a series of experiments using two different species, rats and mice, as animal models. We performed microdialysis, immunohistochemical, pharmacological, sleep deprivation and lesion studies which suggest that the sleep-promoting effects of alcohol may be mediated via alcohol's action on the mediators of sleep homeostasis: adenosine (AD) and the wake-promoting cholinergic neurons of the basal forebrain (BF). Alcohol, via its action on AD uptake, increases extracellular AD resulting in the inhibition of BF wake-promoting neurons. Since binge alcohol consumption is a highly prevalent pattern of alcohol consumption and disrupts sleep, we examined the effects of binge drinking on sleep-wakefulness. Our results suggest that disrupted sleep homeostasis may be the primary cause of sleep disruption observed following binge drinking. Finally, we have also shown that sleep disruptions observed during acute withdrawal, are caused due to impaired

  11. Assessing the aquatic hazard of some branched and linear nonionic surfactants by biodegradation and toxicity

    SciTech Connect

    Dorn, P.B.; Salanitro, J.P.; Evans, S.H.; Kravetz, L. . Westhollow Research Center)

    1993-10-01

    An aquatic hazard assessment was conducted for branched and linear nonionic surfactants using toxicity and biodegradation measurements. Four nonionic alcohol ethoxylate surfactants with different degrees of branching were evaluated for neat surfactant toxicity, degradation in laboratory sewage treatment units, and aquatic toxicity of treated effluents. Acute testing with neat surfactants showed ranges for EC50s of 1.3 to 11.6 mg/L for Daphnia, 1.6 to 6.1 mg/L for Pimephales promelas (fathead minnow), and 1.5 to 11.4 mg/L for Microtox[reg sign]. Chronic testing of algae showed NOECs of 1 to 10 mg/L and maximum acceptable toxicant concentrations (MATCs) of 0.8 to 14.2 mg/L. Seven-day chronic estimation tests showed MATCs of 0.6 to 41.4 mg/L for Pimephales promelas and 1 to 14 mg/L for Daphnia. Effluents collected from treatment units receiving a 50-mg/L surfactant feed at 25 C showed no acute toxicity to either Daphnia or fathead minnows, with the exception of a unit containing nonylphenol ethoxylate. Chronic effluent toxicity was greatest in effluent from the nonylphenol ethoxylate unit and least in the effluent from the linear alcohol ethoxylate unit. Chronic toxicity of the highly branched C[sub 13] alcohol ethoxylate effluent was greater than that for the linear alcohol ethoxylate unit effluent.

  12. Biodegradation and detoxification of textile dye Disperse Red 54 by Brevibacillus laterosporus and determination of its metabolic fate.

    PubMed

    Kurade, Mayur B; Waghmode, Tatoba R; Khandare, Rahul V; Jeon, Byong-Hun; Govindwar, Sanjay P

    2016-04-01

    Bioremediation is one of the milestones achieved by the biotechnological innovations. It is generating superior results in waste management such as removal of textile dyes, which are considered xenobiotic compounds and recalcitrant to biodegradation. In the present bioremedial approach, Brevibacillus laterosporus was used as an effective microbial tool to decolorize disperse dye Disperse Red 54 (DR54). Under optimized conditions (pH 7, 40°C), B. laterosporus led to 100% decolorization of DR54 (at 50 mg L(-1)) within 48 h. Yeast extract and peptone, supplemented in medium enhanced the decolorization efficiency of the bacterium. During the decolorization process, activities of enzymes responsible for decolorization, such as tyrosinase, veratryl alcohol oxidase and NADH--DCIP reductase were induced by 1.32-, 1.51- and 4.37-fold, respectively. The completely different chromatographic/spectroscopic spectrum of metabolites obtained after decolorization confirmed the biodegradation of DR54 as showed by High pressure liquid chromatography, High pressure thin layer chromatography and Fourier transform infrared spectroscopy. Gas chromatography-Mass spectroscopy studies suggested the parent dye was biodegraded into simple final product, N-(1λ(3)-chlorinin-2-yl)acetamide. Phytotoxicity study suggested that the metabolites obtained after biodegradation of DR54 were non-toxic as compared to the untreated dye signifying the detoxification of the DR54 by B. laterosporus.

  13. Synthesis and characterization of sugar-bearing chitosan derivatives: aqueous solubility and biodegradability.

    PubMed

    Park, Jae Hyung; Cho, Yong Woo; Chung, Hesson; Kwon, Ick Chan; Jeong, Seo Young

    2003-01-01

    The extended use of chitosan in biomedical fields has been limited by its insoluble nature in a biological solution. To endow the water solubility in a broad range of pH, chitosan derivatives were prepared by the covalent attachment of a hydrophilic sugar moiety, gluconic acid, through the formation of an amide bond. These sugar-bearing chitosans (SBCs) were further modified by the N-acetylation in an alcoholic aqueous solution. Thereafter, the effect of the gluconyl group and the degree of N-acetylation (DA) on the water solubility at different pHs and on the biodegradability of chitosan were investigated. The SBCs showed the water solubility in a broader range of pH than chitosan, whereas they were still insoluble at neutral and alkali pH. The N-acetylation of SBCs significantly affected the water solubility, for example, the SBCs with the DA, ranging from 29% to 63%, were soluble in the whole range of pH. This might result from the improved hydrophilicity by the gluconyl group, accompanied by the role of the N-acetyl group that disturbed the hydrogen bonding between amino groups of chitosan. From the biodegradation tests, determined by the decrease in the viscosity of a polymer solution exposed to lysozyme, it was evident that the gluconyl group attached to chitosan improved the biodegradability. Thus, it was possible to control the biodegradability of chitosan by adjusting the amounts of gluconyl and N-acetyl groups in the chitosan backbone. The N-acetylated SBCs, soluble in the broad range of pH, might be useful for various biomedical applications.

  14. Evaluating UV/H2O2 processes for methyl tert-butyl ether and tertiary butyl alcohol removal: effect of pretreatment options and light sources.

    PubMed

    Li, Ke; Hokanson, David R; Crittenden, John C; Trussell, Rhodes R; Minakata, Daisuke

    2008-12-01

    In this paper, we evaluate the efficiency of UV/H2O2 process to remove methyl tert-butyl ether (MtBE) and tertiary butyl alcohol (tBA) from a drinking water source. Kinetic models were used to evaluate the removal efficiency of the UV/H2O2 technologies with different pretreatment options and light sources. Two commercial UV light sources, i.e. low pressure, high intensity lamps and medium pressure, high intensity lamps, were evaluated. The following pretreatment alternatives were evaluated: (1) ion exchange softening with seawater regeneration (NaIX); (2) Pellet Softening; (3) weak acid ion exchange (WAIX); and (4) high pH lime softening followed by reverse osmosis (RO). The presence or absence of a dealkalization step prior to the UV/H2O2 Advanced Oxidation Process (AOP) was also evaluated for each pretreatment possibility. Pretreatment has a significant impact on the performance of UV/H2O2 process. The NaIX with dealkalization was shown to be the most cost effective. The electrical energy per order (EEO) values for MtBE and tBA using low pressure high output UV lamps (LPUV) and 10mg/LH2O2 are 0.77 and 3.0 kWh/kgal-order, or 0.20 and 0.79 kWh/m3-order, respectively. For medium pressure UV high output lamps (MPUV), EEO values for MtBE and tBA are 4.6 and 15 kWh/kgal-order, or 1.2 and 4.0 kWh/m3-order, for the same H2O2 dosage.

  15. Biodegradation Of thermoplastic polyurethanes from vegetable oils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermoplastic urethanes based on polyricinoleic acid soft segments and MDI/BD hard segments with varied soft segment concentration were prepared. Soft segment concentration was varied fro, 40 to 70 wt %. Biodegradation was studied by respirometry. Segmented polyurethanes with soft segments based ...

  16. Anaerobic biodegradation of surrogate naphthenic acids.

    PubMed

    Clothier, Lindsay N; Gieg, Lisa M

    2016-03-01

    Surface bitumen extraction from the Alberta's oil sands region generates large settling basins known as tailings ponds. The oil sands process-affected water (OSPW) stored in these ponds contain solid and residual bitumen-associated compounds including naphthenic acids (NAs) that can potentially be biodedgraded by indigenous tailings microorganisms. While the biodegradation of some NAs is known to occur under aerobic conditions, little is understood about anaerobic NA biodegradation even though tailings ponds are mainly anoxic. Here, we investigated the potential for anaerobic NA biodegradation by indigenous tailings microorganisms. Enrichment cultures were established from anoxic tailings that were amended with 5 single-ringed surrogate NAs or acid-extractable organics (AEO) from OSPW and incubated under nitrate-, sulfate-, iron-reducing, and methanogenic conditions. Surrogate NA depletion was observed under all anaerobic conditions tested to varying extents, correlating to losses in the respective electron acceptor (sulfate or nitrate) or the production of predicted products (Fe(II) or methane). Tailings-containing cultures incubated under the different electron-accepting conditions resulted in the enrichment and putative identification of microbial community members that may function in metabolizing surrogate NAs under the various anoxic conditions. In addition, more complex NAs (in the form of AEO) was observed to drive sulfate and iron reduction relative to controls. Overall, this study has shown that simple surrogate NAs can be biodegraded under a variety of anoxic conditions, a key first step in understanding the potential anaerobic metabolism of NAs in oil sands tailings ponds and other industrial wastewaters.

  17. BIODEGRADATION OF ATRAZINE IN SUBSURFACE ENVIRONMENTS

    EPA Science Inventory

    The pesticide atrazine is frequently detected in ground water, including ground water used as drinking water. Little information is available on the fate of atrazine in the subsurface, including its biodegradability. The objectives of this study were to evaluate the biodegradabil...

  18. Neuronal growth and differentiation on biodegradable membranes.

    PubMed

    Morelli, Sabrina; Piscioneri, Antonella; Messina, Antonietta; Salerno, Simona; Al-Fageeh, Mohamed B; Drioli, Enrico; De Bartolo, Loredana

    2015-02-01

    Semipermeable polymeric membranes with appropriate morphological, physicochemical and transport properties are relevant to inducing neural regeneration. We developed novel biodegradable membranes to support neuronal differentiation. In particular, we developed chitosan, polycaprolactone and polyurethane flat membranes and a biosynthetic blend between polycaprolactone and polyurethane by phase-inversion techniques. The biodegradable membranes were characterized in order to evaluate their morphological, physicochemical, mechanical and degradation properties. We investigated the efficacy of these different membranes to promote the adhesion and differentiation of neuronal cells. We employed as model cell system the human neuroblastoma cell line SHSY5Y, which is a well-established system for studying neuronal differentiation. The investigation of viability and specific neuronal marker expression allowed assessment that the correct neuronal differentiation and the formation of neuronal network had taken place in vitro in the cells seeded on different biodegradable membranes. Overall, this study provides evidence that neural cell responses depend on the nature of the biodegradable polymer used to form the membranes, as well as on the dissolution, hydrophilic and, above all, mechanical membrane properties. PCL-PU membranes exhibit mechanical properties that improve neurite outgrowth and the expression of specific neuronal markers.

  19. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    EPA Science Inventory

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. Although this technology has been used to degrade a limited number of inorganics, specifically cyanide and nitr...

  20. Biodegradable polymers derived from amino acids.

    PubMed

    Khan, Wahid; Muthupandian, Saravanan; Farah, Shady; Kumar, Neeraj; Domb, Abraham J

    2011-12-08

    In the past three decades, the use of polymeric materials has increased dramatically for biomedical applications. Many α-amino acids derived biodegradable polymers have also been intensely developed with the main goal to obtain bio-mimicking functional biomaterials. Polymers derived from α-amino acids may offer many advantages, as these polymers: (a) can be modified further to introduce new functions such as imaging, molecular targeting and drugs can be conjugated chemically to these polymers, (b) can improve on better biological properties like cell migration, adhesion and biodegradability, (c) can improve on mechanical and thermal properties and (d) their degradation products are expected to be non-toxic and readily metabolized/excreted from the body. This manuscript focuses on biodegradable polymers derived from natural amino acids, their synthesis, biocompatibility and biomedical applications. It is observed that polymers derived from α-amino acids constitute a promising family of biodegradable materials. These provide innovative multifunctional polymers possessing amino acid side groups with biological activity and with innumerous potential applications.

  1. In vitro biodegradation behavior, mechanical properties, and cytotoxicity of biodegradable Zn-Mg alloy.

    PubMed

    Gong, Haibo; Wang, Kun; Strich, Randy; Zhou, Jack G

    2015-11-01

    Zinc-Magnesium (Zn-Mg) alloy as a novel biodegradable metal holds great potential in biodegradable implant applications as it is more corrosion resistant than Magnesium (Mg). However, the mechanical properties, biodegradation uniformity, and cytotoxicity of Zn-Mg alloy remained as concerns. In this study, hot extrusion process was applied to Zn-1 wt % Mg (Zn-1Mg) to refine its microstructure. Effects of hot extrusion on biodegradation behavior and mechanical properties of Zn-1Mg were investigated in comparison with Mg rare earth element alloy WE43. Metallurgical analysis revealed significant grain size reduction, and immersion test found that corrosion rates of WE43 and Zn-1Mg were reduced by 35% and 57%, respectively after extrusion. Moreover, hot extrusion resulted in a much more uniform biodegradation in extruded Zn-1Mg alloy and WE43. In vitro cytotoxicity test results indicated that Zn-1Mg alloy was biocompatible. Therefore, hot extruded Zn-1Mg with homogenous microstructure, uniform as well as slow degradation, improved mechanical properties, and good biocompatibility was believed to be an excellent candidate material for load-bearing biodegradable implant application.

  2. Does Bioavailability Limit Biodegradability? A Comparison of Hydrocarbon Biodegradation and Desorption Rates in Aged Soils

    SciTech Connect

    Huesemann, Michael H.; Hausmann, Tom S.; Fortman, Timothy J.

    2004-08-01

    In order to determine whether bioavailability limits the biodegradability of petroleum hydrocarbons in aged soils, both the biodegradation and abiotic desorption rates of PAHs and n-alkanes were measured at various time points in six different aged soils undergoing slurry bioremediation treatment. Alkane biodegradation rates were always much greater than the respective desorption rates, indicating that these saturated hydrocarbons do not need to be transferred into the aqueous phase prior to metabolism by soil microorganisms. The biodegradation of PAHs was generally not mass-transfer rate limited during the initial phase, while it often became so at the end of the treatment period when biodegradation rates equaled abiotic desorption rates. However, in all cases where PAH biodegradation was not observed or PAH removal temporarily stalled, bioavailability limitations were not deemed responsible for this recalcitrance since these PAHs desorbed rapidly from the soil into the aqueous phase. Consequently, aged PAHs that are often thought to be recalcitrant due to bioavailability limitations may not be so and therefore may pose a greater risk to environmental receptors than previously thought.

  3. Does bioavailability limit biodegradation? A comparison of hydrocarbon biodegradation and desorption rates in aged soils.

    PubMed

    Huesemann, Michael H; Hausmann, Tom S; Fortman, Tim J

    2004-08-01

    In order to determine whether bioavailability limits the biodegradability of petroleum hydrocarbons in aged soils, both the biodegradation and abiotic desorption rates of PAHs and n-alkanes were measured at various time points in six different aged soils undergoing slurry bioremediation treatment. Alkane biodegradation rates were always much greater than the respective desorption rates, indicating that these saturated hydrocarbons apparently do not need to be dissolved into the aqueous phase prior to metabolism by soil microorganisms. The biodegradation of PAHs was generally not mass-transfer rate limited during the initial phase, while it often became so at the end of the treatment period when biodegradation rates equaled abiotic desorption rates. However, in all cases where PAH biodegradation was not observed or PAH removal temporarily stalled, bioavailability limitations were not deemed responsible for this recalcitrance since these PAHs desorbed rapidly from the soil into the aqueous phase. Consequently, aged PAHs that are often thought to be recalcitrant due to bioavailability limitations may not be so and therefore may pose a greater risk to environmental receptors than previously thought.

  4. Carbon and Hydrogen Isotopic Fractionation during Anaerobic Biodegradation of Benzene

    PubMed Central

    Mancini, Silvia A.; Ulrich, Ania C.; Lacrampe-Couloume, Georges; Sleep, Brent; Edwards, Elizabeth A.; Sherwood Lollar, Barbara

    2003-01-01

    Compound-specific isotope analysis has the potential to distinguish physical from biological attenuation processes in the subsurface. In this study, carbon and hydrogen isotopic fractionation effects during biodegradation of benzene under anaerobic conditions with different terminal-electron-accepting processes are reported for the first time. Different enrichment factors (ɛ) for carbon (range of −1.9 to −3.6‰) and hydrogen (range of −29 to −79‰) fractionation were observed during biodegradation of benzene under nitrate-reducing, sulfate-reducing, and methanogenic conditions. These differences are not related to differences in initial biomass or in rates of biodegradation. Carbon isotopic enrichment factors for anaerobic benzene biodegradation in this study are comparable to those previously published for aerobic benzene biodegradation. In contrast, hydrogen enrichment factors determined for anaerobic benzene biodegradation are significantly larger than those previously published for benzene biodegradation under aerobic conditions. A fundamental difference in the previously proposed initial step of aerobic versus proposed anaerobic biodegradation pathways may account for these differences in hydrogen isotopic fractionation. Potentially, C-H bond breakage in the initial step of the anaerobic benzene biodegradation pathway may account for the large fractionation observed compared to that in aerobic benzene biodegradation. Despite some differences in reported enrichment factors between cultures with different terminal-electron-accepting processes, carbon and hydrogen isotope analysis has the potential to provide direct evidence of anaerobic biodegradation of benzene in the field. PMID:12513995

  5. Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

    PubMed

    Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

    2002-10-01

    The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor.

  6. Study of fuel oxygenates solubility in aqueous media as a function of temperature and tert-butyl alcohol concentration.

    PubMed

    Gonzalez-Olmos, R; Iglesias, M

    2008-05-01

    Methyl tert-butyl ether (MTBE) is the most widely used oxygenate in gasoline blending and has become one of the world's most widespread groundwater and surface water pollutants. Alternative oxygenates to MTBE, namely ethyl tert-butyl ether (ETBE), tert-amyl ether (TAME) and diisopropyl ether (DIPE) have been hardly studied yet. The solubility of these chemicals is a key thermodynamic information for the assessment of the fate and transport of these pollutants. This work reports experimental data of water solubility at the range from 278.15 to 313.15K and atmospheric pressure of ethers used in fuels (MTBE, ETBE, TAME and DIPE) due to the strong influence of temperature on its trend. From the experimental data, temperature dependent polynomials were fitted, thermodynamic parameters were calculated and theoretical models were used for prediction. Finally, the tert-butyl alcohol (TBA) influence in the solubility of MTBE and ETBE in aqueous media was studied.

  7. Synergic effect of acetal-based resin by blending with poly[4-hydroxy styrene-co-tert-butyl acrylate-co-4-(3-cyano-1,5-di-tert-butyl carbonyl pentyl styrene)] (P(HS-TBA-CBPS)) on the profiles of 248 nm chemically amplified resist

    NASA Astrophysics Data System (ADS)

    Kim, Hyun-Jin; Chung, Yoon-Sik; Lee, Dong H.; Cho, Sook H.; Im, Kwang H.; Yim, Yun-Gill; Kim, Deog-Bae; Kim, Jae-Hyun

    2002-07-01

    We prepared ter-polymer of hydroxystyrene, tert-butyl acrylate and 4-(3-cyano-1,5-di-tert-butyl carbonyl pentyl styrene) (P(HS-TBA-CBPS)) and discussed a characteristic of prepared polymer. As TBA, newly introduced monomer increases, contrast of resist is improved. And the prepared polymer was blended with poly(4-hydroxystyrene-co-4-(1-ethylethoxystyrene)) (EE-PHS). The synergic effect on a resist performance in KrF lithography by the combination of high and low activation energy system was shown. A resist using blending polymer was shown a good performance on resolution and LER(Line Edge Roughness) than resist using polymer separately. Based on the results, it was found that high performance KrF resist could be obtained by optimization of polymer blending.

  8. [Alcohol and crime].

    PubMed

    Lévay, Boglárka

    2006-01-01

    The role alcohol abuse plays in criminality has been a matter of primary concern for scholars for decades, as indicated by numerous studies and research projects. Most of these studies focus on determining the presence of a relationship between criminal behaviour and alcohol use, and whether criminal inclinations increase with the consumption of alcohol. Research shows that alcohol use indeed increases the risk of criminal behaviour, and that there is an especially strong and consistent correlation between alcohol abuse and violent crimes. However, researchers still disagree on the exact extent to which alcohol use effects criminality, and on the mechanisms causing alcohol to induce violent behaviour. A significant proportion of studies have focused in recent years on aggressive behaviour as a result of drinking alcohol. One of the most important means of measurement is the study of violent behaviour in places where alcohol is on sale. Studying the forms and frequency of violence in pubs and near off-licence stores greatly enables experts to understand the general context of the problem. This is the reason for the increasing interest in the topic throughout the past few decades. The present study focuses mainly on the literature published in English and German in leading journals of criminology since 1980, as well as on the most recent and fundamental publications on the topic, with special regard to results concerning drinking habits, and the relationship between drinking alcohol and violent or criminal behaviour, respectively.

  9. Alcohol and suicidal behavior.

    PubMed

    Hufford, M R

    2001-07-01

    Alcohol dependence and alcohol intoxication are important risk factors for suicidal behavior. However, the mechanism for the relationship remains unclear. This review presents a conceptual framework relating alcohol to suicidal behavior. Distal risk factors create a statistical potential for suicide. Alcohol dependence, as well as associated comorbid psychopathology and negative life events, act as distal risk factors for suicidal behavior. Proximal risk factors determine the timing of suicidal behavior by translating the statistical potential of distal risk factors into action. The acute effects of alcohol intoxication act as important proximal risk factors for suicidal behavior among the alcoholic and nonalcoholic alike. Mechanisms responsible for alcohol's ability to increase the proximal risk for suicidal behavior include alcohol's ability to: (1) increase psychological distress, (2) increase aggressiveness, (3) propel suicidal ideation into action through suicide-specific alcohol expectancies, and (4) constrict cognition which impairs the generation and implementation of alternative coping strategies. Moreover, the proximal risk factors associated with acute intoxication are consistent with Baumeister's (1990) escape theory of suicide. Suggestions for additional research are discussed, including the possibility that a nonlinear cusp catastrophe model characterizes the relationship between alcohol intoxication and suicidal behavior.

  10. Genetics of alcoholism.

    PubMed

    Schuckit, M A; Li, T K; Cloninger, C R; Deitrich, R A

    1985-12-01

    Great progress has been made by research on the contribution genetic factors make to a vulnerability toward alcoholism. Animal studies have demonstrated the importance of genetics in ethanol preference and levels of consumption, and human family, twin, and adoption research have revealed a 4-fold higher risk for offspring of alcoholics, even if they were adopted out at birth. The work presented in this symposium reviews the ongoing search for genetic trait markers of a vulnerability toward alcoholism. Dr. Li has used both animal and human research to demonstrate the possible importance of the genetic control of enzymes involved in ethanol metabolism and has worked to help develop an animal model of alcoholism. The possible importance of subgroups with different levels of predisposition toward alcoholism is emphasized by Dr. Cloninger. An overview of the studies of sons of alcoholics, given by Dr. Schuckit, reveals the potential importance of a decreased intensity of reaction to ethanol as part of a predisposition toward alcoholism and discusses the possible impact of some brain waves and ethanol metabolites to an alcoholism vulnerability. Dr. Deitrich reviews interrelationships between studies of animals and humans in the search for factors involved in a genetic vulnerability toward alcoholism. Taken together, these presentations underscore the importance of genetic factors in alcoholism, review animal and human research attempting to identify markers of a vulnerability, and reveal the high level of interaction between human and animal research.

  11. Improving the biodegradative capacity of subsurface bacteria

    SciTech Connect

    Romine, M.F.; Brockman, F.J.

    1993-04-01

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates.

  12. Exposure to Televised Alcohol Ads and Subsequent Adolescent Alcohol Use

    ERIC Educational Resources Information Center

    Stacy, Alan W.; Zogg, Jennifer B.; Unger, Jennifer B.; Dent, Clyde W.

    2004-01-01

    Objective : To assess the impact of televised alcohol commercials on adolescents' alcohol use. Methods : Adolescents completed questionnaires about alcohol commercials and alcohol use in a prospective study. Results : A one standard deviation increase in viewing television programs containing alcohol commercials in seventh grade was associated…

  13. Alcohol Expectancies in Young Adult Sons of Alcoholics and Controls.

    ERIC Educational Resources Information Center

    Brown, Sandra A.; And Others

    Adolescent offspring of alcoholics have been found to have higher alcohol reinforcement expectancies than do teenagers from nonalcoholic families. In particular, those with a positive family history of alcoholism expect more cognitive and motor enhancement with alcohol consumption. This study examined the alcohol expectancies of 58 matched pairs…

  14. Update on Alcoholic Hepatitis.

    PubMed

    Torok, Natalie J

    2015-11-02

    Alcoholic liver disease is one of the most prevalent liver diseases worldwide, and a major cause of morbidity and mortality. Alcoholic hepatitis is a severe form of liver injury in patients with alcohol abuse, can present as an acute on chronic liver failure associated with a rapid decline in liver synthetic function, and consequent increase in mortality. Despite therapy, about 30%-50% of patients with severe alcoholic hepatitis eventually die. The pathogenic pathways that lead to the development of alcoholic hepatitis are complex and involve oxidative stress, gut dysbiosis, and dysregulation of the innate and adaptive immune system with injury to the parenchymal cells and activation of hepatic stellate cells. As accepted treatment approaches are currently limited, a better understanding of the pathophysiology would be required to generate new approaches that improve outcomes. This review focuses on recent advances in the diagnosis, pathogenesis of alcoholic hepatitis and novel treatment strategies.

  15. Alcohol in human history.

    PubMed

    Vallee, B L

    1994-01-01

    The role of ethanol in the history of human development is here summarized under seven topics: I. Alcohol: the substitute for water as the major human beverage; II. Alcohol as a component of the diet and source of calories; III. Alcohol, concentration by distillation; IV. The Reformation, Temperance and Prohibition; V. Potable nonalcoholic beverages: Boiled water (coffee, tea); VI. Purification and sanitation of water; VII. The present and future.

  16. Alcohol use and menopause.

    PubMed

    Wilsnack, Richard W; Wilsnack, Sharon C

    2016-04-01

    Clinicians should periodically assess their menopausal patients' alcohol use. Specific health hazards from excessive alcohol consumption, as well as potential benefits of low-level consumption (for cardiovascular disease, bone health, and type 2 diabetes), should be discussed with their patients who drink. The information in this Practice Pearl can help clinicians provide evidence-based guidance about alcohol consumption and its relationship to common health concerns.

  17. [Biological markers of alcoholism].

    PubMed

    Marcos Martín, M; Pastor Encinas, I; Laso Guzmán, F J

    2005-09-01

    Diagnosis of alcoholism is very important, given its high prevalence and possibility of influencing the disease course. For this reason, the so-called biological markers of alcoholism are useful. These are analytic parameters that alter in the presence of excessive alcohol consumption. The two most relevant markers are the gamma-glutamyltranspeptidase and carbohydrate deficient transferrin. With this clinical comment, we aim to contribute to the knowledge of these tests and promote its use in the clinical practice.

  18. Fetal Alcohol Syndrome "Chemical Genocide."

    ERIC Educational Resources Information Center

    Asetoyer, Charon

    In the Northern Plains of the United States, 100% of Indian reservations are affected by alcohol related problems. Approximately 90% of Native American adults are currently alcohol users or abusers or are recovering from alcohol abuse. Alcohol consumption has a devastating effect on the unborn. Fetal Alcohol Syndrome (FAS) is an irreversible birth…

  19. Tobacco, Alcohol, Drugs, and Pregnancy

    MedlinePlus

    ... What are fetal alcohol spectrum disorders? • What is fetal alcohol syndrome? • What amounts of alcohol can cause FAS? • Is ... disabilities that can last a lifetime. What is fetal alcohol syndrome? Fetal alcohol syndrome (FAS) is the most severe ...

  20. Alcoholic liver disease

    PubMed Central

    Walsh, K.; Alexander, G.

    2000-01-01

    Alcohol is a major cause of liver cirrhosis in the Western world and accounts for the majority of cases of liver cirrhosis seen in district general hospitals in the UK. The three most widely recognised forms of alcoholic liver disease are alcoholic fatty liver (steatosis), acute alcoholic hepatitis, and alcoholic cirrhosis. The exact pathogenesis of alcoholic liver injury is still not clear but immune mediated and free radical hepatic injury are thought to be important. There is increasing interest in genetic factors predisposing to hepatic injury in susceptible individuals. Diagnosis is based on accurate history, raised serum markers such as γ-glutamyltransferase, mean corpuscular volume, and IgA and liver histology when obtainable. Abstinence is the most important aspect of treatment. Newer drugs such as acamprosate and naltrexone are used to reduce alcohol craving. Vitamin supplements and nutrition are vital while corticosteroids have a role in acute alcoholic hepatitis where there is no evidence of gastrointestinal haemorrhage or sepsis. Liver transplantation has excellent results in abstinent patients with end stage liver disease but there are concerns about recidivism after transplant.


Keywords: cirrhosis; liver disease; alcohol PMID:10775280

  1. [Biodegradable catheters and urinary stents. When?

    PubMed

    Soria, F; Morcillo, E; López de Alda, A; Pastor, T; Sánchez-Margallo, F M

    2016-10-01

    One of the main wishes in the field of urinary catheters and stents is to arm them with biodegradable characteristics because we consider a failure of these devices the need for retrieval, the forgotten catheter syndrome as well as the adverse effects permanent devices cause after fulfilling their aim. The efforts focused in new designs, coatings and biomaterials aim to increase the biocompatibility of theses internal devices. Lately, there have been correct advances to answer the main challenges regarding biodegradable ureteral devices. Thus, modulation of the rate of degradation has been achieved thanks to new biomaterials and the use of copolymers that enable to choose the time of permanence as it is programmed with conventional double J catheters. Biocompatibility has improved with the use of new polymers that adapt better to the urine. Finally, one of the main problems is elimination of degraded fragments and experimentally it has be demonstrated that new designs elicit controlled degradation, from distal to proximal; using stranding and combination of copolymers degradation may be caused by dilution, reducing fragmentation to the last stages of life of the prosthesis. Moreover, it has been demonstrated that biodegradable catheters potentially may cause less urinary tract infection, less encrustation and predictably they will diminish catheter morbidity, since their degradation process reduces adverse effects. Regarding the development of biodegradable urethral stents, it is necessary to find biomaterials that enable maintaining their biomechanical properties in the long term, keeping open the urethral lumen both in patients with BPH and urethral stenosis. Modulation of the time of degradation of the prosthesis has been achieved, but the appearance of urothelial hyperplasia is still a constant in the initial phases after implantation. The development of drug eluting stents, anti-proliferative or anti-inflammatory, as well as biodegradable stents biocoated is a

  2. Prenatal alcohol consumption and knowledge about alcohol consumption and fetal alcohol syndrome in Korean women.

    PubMed

    Kim, Oksoo; Park, Kyungil

    2011-09-01

    The study investigated prenatal alcohol consumption and knowledge of alcohol risks and fetal alcohol syndrome among Korean women. The participants were 221 Korean women who attended the post-partum care centers in Seoul, Korea. The data included the participants' background characteristics, quantity-frequency typology, Student Alcohol Questionnaire, and a scale on the participants' knowledge of fetal alcohol syndrome. Alcohol was consumed during pregnancy by 12.7% of the participants. Of these, 60.7% drank alcohol with their spouse. A few participants reported that nurses identified their drinking habits and gave them information on alcohol consumption and fetal alcohol syndrome. Most of the participants did not have the opportunity for prenatal counseling about fetal alcohol syndrome. The knowledge level regarding alcohol risks and fetal alcohol syndrome among the participants was poor. Alcohol consumption before pregnancy was significantly related to prenatal alcohol consumption. Prenatal alcohol consumption was not related to knowledge about alcohol consumption and fetal alcohol syndrome. The assessment of alcohol consumption and counseling about alcohol are needed for pregnant women in order to prevent fetal alcohol syndrome.

  3. Defining maximum levels of higher alcohols in alcoholic beverages and surrogate alcohol products.

    PubMed

    Lachenmeier, Dirk W; Haupt, Simone; Schulz, Katja

    2008-04-01

    Higher alcohols occur naturally in alcoholic beverages as by-products of alcoholic fermentation. Recently, concerns have been raised about the levels of higher alcohols in surrogate alcohol (i.e., illicit or home-produced alcoholic beverages) that might lead to an increased incidence of liver diseases in regions where there is a high consumption of such beverages. In contrast, higher alcohols are generally regarded as important flavour compounds, so that European legislation even demands minimum contents in certain spirits. In the current study we review the scientific literature on the toxicity of higher alcohols and estimate tolerable concentrations in alcoholic beverages. On the assumption that an adult consumes 4 x 25 ml of a drink containing 40% vol alcohol, the maximum tolerable concentrations of 1-propanol, 1-butanol, 2-butanol, isobutanol, isoamyl alcohol and 1-hexanol in such a drink would range between 228 and 3325 g/hl of pure alcohol. A reasonable preliminary guideline level would be 1000 g/hl of pure alcohol for the sum of all higher alcohols. This level is higher than the concentrations usually found in both legal alcoholic beverages and surrogate alcohols, so that we conclude that scientific data are lacking so far to consider higher alcohols as a likely cause for the adverse effects of surrogate alcohol. The limitations of our study include the inadequate toxicological data base leading to uncertainties during the extrapolation of toxicological data between the different alcohols, as well as unknown interactions between the different higher alcohols and ethanol.

  4. Biodegradability of biodegradable/degradable plastic materials under aerobic and anaerobic conditions.

    PubMed

    Mohee, R; Unmar, G D; Mudhoo, A; Khadoo, P

    2008-01-01

    A study was conducted on two types of plastic materials, Mater-Bi Novamont (MB) and Environmental Product Inc. (EPI), to assess their biodegradability under aerobic and anaerobic conditions. For aerobic conditions, organic fractions of municipal solid wastes were composted. For the anaerobic process, anaerobic inoculum from a wastewater treatment plant was used. Cellulose filter papers (CFP) were used as a positive control for both mediums. The composting process was monitored in terms of temperature, moisture and volatile solids and the biodegradation of the samples were monitored in terms of mass loss. Monitoring results showed a biodegradation of 27.1% on a dry basis for MB plastic within a period of 72 days of composting. Biodegradability under an anaerobic environment was monitored in terms of biogas production. A cumulative methane gas production of 245 ml was obtained for MB, which showed good degradation as compared to CFP (246.8 ml). However, EPI plastic showed a cumulative methane value of 7.6 ml for a period of 32 days, which was close to the blank (4.0 ml). The EPI plastic did not biodegrade under either condition. The cumulative carbon dioxide evolution after 32 days was as follows: CFP 4.406 cm3, MB 2.198 cm3 and EPI 1.328 cm3. The cumulative level of CO2 varying with time fitted sigmoid type curves with R2 values of 0.996, 0.996 and 0.995 for CFP, MB and EPI, respectively.

  5. Alcohol-Related Liver Disease

    MedlinePlus

    ... events. Please support us. Donate | Volunteer Alcohol-Related Liver Disease Discussion on Inspire Support Community Join the ... Disease Information > Alcohol-Related Liver Disease Alcohol-Related Liver Disease Explore this section to learn more about ...

  6. Biodegradation of superabsorbent polymers in soil.

    PubMed

    Stahl, J D; Cameron, M D; Haselbach, J; Aust, S D

    2000-01-01

    Biodegradation of two superabsorbent polymers, a crosslinked, insoluble polyacrylate and an insoluble polyacrylate/ polyacrylamide copolymer, in soil by the white-rot fungus, Phanerochaete chrysosporium was investigated. The polymers were both solubilized and mineralized by the fungus but solubilization and mineralization of the copolymer was much more rapid than of the polyacrylate. Soil microbes poorly solublized the polymers and were unable to mineralize either intact polymer. However, soil microbes cooperated with the fungus during polymer degradation in soil, with the fungus solubilizing the polymers and the soil microbes stimulating mineralization. Further, soil microbes were able to significantly mineralize both polymers after solubilization by P. chrysosporium grown under conditions that produced fungal peroxidases or cellobiose dehydrogenase, or after solubilization by photochemically generated Fenton reagent. The results suggest that biodegradation of these polymers in soil is best under conditions that maximize solubilization.

  7. Modeling ready biodegradability of fragrance materials.

    PubMed

    Ceriani, Lidia; Papa, Ester; Kovarich, Simona; Boethling, Robert; Gramatica, Paola

    2015-06-01

    In the present study, quantitative structure activity relationships were developed for predicting ready biodegradability of approximately 200 heterogeneous fragrance materials. Two classification methods, classification and regression tree (CART) and k-nearest neighbors (kNN), were applied to perform the modeling. The models were validated with multiple external prediction sets, and the structural applicability domain was verified by the leverage approach. The best models had good sensitivity (internal ≥80%; external ≥68%), specificity (internal ≥80%; external 73%), and overall accuracy (≥75%). Results from the comparison with BIOWIN global models, based on group contribution method, show that specific models developed in the present study perform better in prediction than BIOWIN6, in particular for the correct classification of not readily biodegradable fragrance materials.

  8. Enhanced biodegradation resistance of biomodified jute fibers.

    PubMed

    Manna, Suvendu; Saha, Prosenjit; Roy, Debasis; Sen, Ramkrishna; Adhikari, Basudam; Das, Sancharini

    2013-04-02

    A bio-catalyzed process has been developed for treating jute fibers to enhance their tensile strength and resistance against biodegradation. Lipolytic bacteria were used in the process to transesterify jute fibers by replacing hydrophilic hydroxyl groups within cellulose chains with hydrophobic fatty acyl chains. Transesterification of some of the hydroxyl groups within the fiber was confirmed with FTIR, UV-vis spectroscopy, (13)C solid state NMR, gas chromatography and analytical determination of ester content. Biomodified fibers exhibited remarkably smaller affinity to water and moisture and retained 62% of their initial tensile strengths after being exposed to a composting environment over 21 days. The corresponding figure for untreated fibers was only 30%. Efficacy of the process reported herein in terms of tensile strength and biodegradation resistance enhancement of fibers achieved after treatment appears to be comparable with similar chemical processes and better than the enzyme-catalyzed alternatives.

  9. Biodegradable, hydrophobic coatings based on crosslinked polycaprolactone

    SciTech Connect

    Koenig, M.F.

    1993-12-31

    Crosslinked poly(caprolactone) (PCL) has been explored as a hydrophobic and biodegradable coating for hydrophilic substrates. Crosslinking of PCL is known to retard its degradation rate, but does not affect its biodegradability. The cross-linking efficiencies of several organic peroxides have been determined for PCL. This has been accomplished by calculating the crosslink density (M{sub c} from dynamic mechanical data) for a given molar concentration of organic peroxide. Various thicknesses of crosslinked PCL have been coated on several different hydrophilic substrates, including paper, MaterBi (regsign), and PCL/starch composites. The hydrophobicity of the coating has been measured by following the weight gain of the coated samples upon exposure to water and a high relative humidity for various lengths of time. Results show that a coating as thin as 10 {mu}m reduces water absorption of paper by a factor of five, and thicker coatings (0.25 mm) by more than two orders of magnitude.

  10. [Development of biodegradable magnesium-based biomaterials].

    PubMed

    Zhu, Shengfa; Xu, Li; Huang, Nan

    2009-04-01

    Magnesium is a macroelement which is indispensable to human bodies. As a lightweight metal with high specific strength and favorable biocompatibility, magnesium and its alloys have been introduced in the field of biomedical materials research and have a broad application prospect. It is possible to develop new type of biodegradable medical magnesium alloys by use of the poor corrosion resistance of magnesium. Bioabsorbable magnesium stents implanted in vivo could mechanically support the vessel in a short term, effectly prevent the acute coronary occlusion and in-stent restenosis, and then be gradully biodegraded and completely absorbed in a long term. Osteoconductive bioactivity in magnesium-based alloys could promote the apposition growth of bone tissue. This paper reviews the progress of magnesium and its alloys applied in bone tissue and cardiovascular stents, and the prospect of the future research of magnesium-based biomaterials is discussed.

  11. Biodegradable foam plastics based on castor oil.

    PubMed

    Wang, Hong Juan; Rong, Min Zhi; Zhang, Ming Qiu; Hu, Jing; Chen, Hui Wen; Czigány, Tibor

    2008-02-01

    In this work, a simple but effective approach was proposed for preparing biodegradable plastic foams with a high content of castor oil. First of all, castor oil reacted with maleic anhydride to produce maleated castor oil (MACO) without the aid of any catalyst. Then plastic foams were synthesized through free radical initiated copolymerization between MACO and diluent monomer styrene. With changes in MACO/St ratio and species of curing initiator, mechanical properties of MACO foams can be easily adjusted. In this way, biofoams with comparable compressive stress at 25% strain as commercial polyurethane (PU) foams were prepared, while the content of castor oil can be as high as 61 wt %. The soil burial tests further proved that the castor oil based foams kept the biodegradability of renewable resources despite the fact that some petrol-based components were introduced.

  12. Biodegradable inflatable balloons for tissue separation.

    PubMed

    Basu, Arijit; Haim-Zada, Moran; Domb, Abraham J

    2016-10-01

    Confining radiation to a specific region (during radiation therapy) minimizes damage to surrounding tissues. Biodegradable inflatable balloons (bio-balloons) were developed. The device protects the normal tissues by increasing the gap between radiation source and critical structures. The radiation fades away while passing through the inflated balloon preventing the surrounding tissues from harmful radiation. These bio-balloons have also found clinical use to treat massive rotator cuff tear. This review summarizes the chemistry, engineering, and clinical development of these biomedical devices. These balloons are made of biodegradable polymers folded into the edge of a trocar and inserted between the tissues to be separated, and inflated by normal saline in the site of the application. The inserted balloon protects the tissues from radiation or mechanical stress. They remain inflated on site for two months and are finally eliminated within 12 months.

  13. Neutralization and Biodegradation of Sulfur Mustard.

    DTIC Science & Technology

    1997-02-01

    obtained from activated sludge (Back River Wastewater Treatment Plant, Baltimore, MD). Initial mixed liquor suspended solids (MLSS) levels were...BIODEGRADATION OF SULFUR MUSTARD Steven P. Harvey Linda L. Szafraniec William T. Beaudry RESEARCH AND TECHNOLOGY DIRECTORATE James T. Earley SBR TECHNOLOGIES, INC... SBR Technologies, Inc.); and Irvine, Robert L. (University of Notre Dame) 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION

  14. Natural biodegradation of organic contaminants in groundwater

    SciTech Connect

    McNab, W W; Rice, D W

    1998-09-23

    There has recently been a growing awareness that natural processes are degrading contaminants of concern, and that the contribution these natural processes make to achieving cleanup goals needs to be formally considered during site-specific cleanup. Historical case data from a large number of releases has been used to evaluate the expectation for natural attenuation to contribute to the cleanup of petroleum hydrocarbons and chlorinated solvents. The use of historical case data has several advantages, among them: 1) sites can reduce characterization costs by sharing information on key hydrogeologic parameters controlling contaminant fate and transport, and 2) standard reference frameworks can be developed that individual sites can use as a basis of comparison regarding plume behavior. Definition of cleanup times must take into account basic constraints imposed by natural laws governing the transport and natural degradation process of petroleum hydrocarbons. The actual time to reach groundwater cleanup goals is determined by these laws and the limitations on residual subsurface contamination attenuation rates, through either active or natural biological processes. These limitations will practically constrain the time to achieve low concentration cleanup goals. Recognition is needed that sites will need to be transitioned to remediation by natural processes at some point following implementation of active remediation options. The results of an analysis of approximately 1800 California and 600 Texas fuel hydrocarbon (FHC) releases and 2.50 chlorinated volatile organic compound (CVOC) plumes will be summarized. Plume lengths and natural biodegradation potential were evaluated. For FHC releases, 90% of benzene groundwater plumes were less than 280 feet in length and evidence of natural biodegradation was found to be present at all sites studied in detail. For CVOC releases, source strength and groundwater flow velocity are dominant factors controlling groundwater plume

  15. Coatings and Biodegradable and Bioasorbable Films

    DTIC Science & Technology

    2006-12-28

    or organic modifier, and the content of organo - clay affect the morphological, mechanical and thermal properties of the nanocomposites. The in-situ...Pages 35-37 Highly Exfoliated Poly(E-caprolactone)/ Organo -montmorillonite Nanocomposites by in-Situ Polymerization Mathias Pages 38-58 Environmentally...Wicks Biodegradation of polymeric materials in the environment is a complex process involving concurrent actions of chemical, photochemical and

  16. Polymer blends with biodegradable components and reinforcements

    NASA Astrophysics Data System (ADS)

    Sartore, Luciana; Di Landro, Luca

    2014-05-01

    Polymeric blends based on ethylene vinyl acetate rubbers filled with high mol. wt. carboxymethyl cellulose were investigated in view of possible employment as biodegradable materials. The effect of vinyl acetate content and of addition of transesterification agent to increase interaction between EVA and cellulosic components was considered. Blends reinforced with cellulose microfibers in different amounts were also characterized in their mechanical, rheological and thermal behavior.

  17. Behaviour of biodegradable plastics in composting facilities.

    PubMed

    Körner, I; Redemann, K; Stegmann, R

    2005-01-01

    Composting is a preferred treatment strategy for biodegradable plastics (BDPs). In this sense, the collection of BDPs together with organic household wastes is a highly discussed possibility. Under the aspect of the behaviour of BDPs in composting facilities, a telephone survey was carried out with selected composting facility operators. They were interviewed with respect to treated wastes, content of impurities, processes for impurity separation, experiences with biodegradable plastics and assumptions to the behaviour of biodegradable plastics in their facility. Forty percent of the facilities had some experiences with BDPs due to test runs, and also since the occurrence of BDPs in their waste was known. The majority of the operators expressed apprehension regarding an increase of impurities resulting from a combined collection of biowaste and BDPs. In the facilities, measures for the impurity separation from the biowaste were used in common practice - in 33% of the cases, separation of disturbing plastics was done before composting, in 33% after composting, and in 13% before and after composting. The most important separation processes for conventional plastics were sieving and manual sorting. In two cases air classification was also used. When asked about the separation possibility of the conventional but not of the biodegradable plastics in their facilities, the majority of operators were not in a position to comment or they replied that it was not an option. No problems were seen in most cases if the impurity separation follows composting. If impurity separation takes place before composting it was often assumed that the BDPs are mainly separated by sieving. In conclusion, in more than half of the cases, BDPs would not be composted if delivered to a composting facility. Under the actual conditions regarding the collection and the treatment/disposal possibilities, an application of BDPs seems to only be reasonable for clean (i.e., source separated on their own

  18. Polymers from plants to develop biodegradable plastics.

    PubMed

    Conrad, Udo

    2005-11-01

    Katrin Neumann et al. have recently shown that transgenic tobacco and potato plants can accumulate high levels of cyanophycin, a possible source for poly-aspartate. This work opens the way to the future production of biodegradable plastics using a plant-based production system. Several problems need to be overcome first, such as growth retardation as a result of cyanophycin accumulating in the cytosol, and a co-production system needs to be developed for economical reasons.

  19. Synthetic biodegradable polymers for orthopaedic applications.

    PubMed

    Behravesh, E; Yasko, A W; Engel, P S; Mikos, A G

    1999-10-01

    Synthetic biodegradable polymers offer an alternative to the use of autografts, allografts, and nondegradable materials for bone replacement. They can be synthesized with tailored mechanical and degradative properties. They also can be processed to porous scaffolds with desired pore morphologic features conducive to tissue ingrowth. Moreover, functionalized polymers can modulate cellular function and induce tissue ingrowth. This review focuses on four classes of polymers that hold promise for orthopaedic applications: poly alpha-hydroxy esters, polyphosphazenes, polyanhydrides, and polypropylene fumarate crosslinked networks.

  20. Biodegradation of hexachlorocyclohexane (HCH) by microorganisms.

    PubMed

    Phillips, Theresa M; Seech, Alan G; Lee, Hung; Trevors, Jack T

    2005-08-01

    The organochlorine pesticide Lindane is the gamma-isomer of hexachlorocyclohexane (HCH). Technical grade Lindane contains a mixture of HCH isomers which include not only gamma-HCH, but also large amounts of predominantly alpha-, beta- and delta-HCH. The physical properties and persistence of each isomer differ because of the different chlorine atom orientations on each molecule (axial or equatorial). However, all four isomers are considered toxic and recalcitrant worldwide pollutants. Biodegradation of HCH has been studied in soil, slurry and culture media but very little information exists on in situ bioremediation of the different isomers including Lindane itself, at full scale. Several soil microorganisms capable of degrading, and utilizing HCH as a carbon source, have been reported. In selected bacterial strains, the genes encoding the enzymes involved in the initial degradation of Lindane have been cloned, sequenced, expressed and the gene products characterized. HCH is biodegradable under both oxic and anoxic conditions, although mineralization is generally observed only in oxic systems. As is found for most organic compounds, HCH degradation in soil occurs at moderate temperatures and at near neutral pH. HCH biodegradation in soil has been reported at both low and high (saturated) moisture contents. Soil texture and organic matter appear to influence degradation presumably by sorption mechanisms and impact on moisture retention, bacterial growth and pH. Most studies report on the biodegradation of relatively low (< 500 mg/kg) concentrations of HCH in soil. Information on the effects of inorganic nutrients, organic carbon sources or other soil amendments is scattered and inconclusive. More in-depth assessments of amendment effects and evaluation of bioremediation protocols, on a large scale, using soil with high HCH concentrations, are needed.

  1. Molecular basis of alcoholism.

    PubMed

    Most, Dana; Ferguson, Laura; Harris, R Adron

    2014-01-01

    Acute alcohol intoxication causes cellular changes in the brain that last for hours, while chronic alcohol use induces widespread neuroadaptations in the nervous system that can last a lifetime. Chronic alcohol use and the progression into dependence involve the remodeling of synapses caused by changes in gene expression produced by alcohol. The progression of alcohol use, abuse, and dependence can be divided into stages, which include intoxication, withdrawal, and craving. Each stage is associated with specific changes in gene expression, cellular function, brain circuits, and ultimately behavior. What are the molecular mechanisms underlying the transition from recreational use (acute) to dependence (chronic)? What cellular adaptations result in drug memory retention, leading to the persistence of addictive behaviors, even after prolonged drug abstinence? Research into the neurobiology of alcoholism aims to answer these questions. This chapter will describe the molecular adaptations caused by alcohol use and dependence, and will outline key neurochemical participants in alcoholism at the molecular level, which are also potential targets for therapy.

  2. Alcoholism: A Developmental Disorder.

    ERIC Educational Resources Information Center

    Tarter, Ralph E.; Vanyukov, Michael

    1994-01-01

    Alcoholism etiology is discussed from developmental behavior genetic perspective. Temperament features that appear to be associated with heightened risk for alcoholism are examined. Their interactions with the environment during course of development are considered within epigenetic framework and, as discussed, have ramifications for improving…

  3. The Fetal Alcohol Syndrome.

    ERIC Educational Resources Information Center

    Umbreit, John; Ostrow, Lisa S.

    1980-01-01

    Fetal alcohol syndrome is a pattern of altered growth and morphogenesis found in about half the offspring of severely and chronically alcoholic women who continue drinking throughout their pregnancy. Of children studied, mild to moderate mental retardation was the most common disorder, occurring in 44 percent of the cases. (PHR)

  4. Fetal Alcohol Spectrum Disorder

    ERIC Educational Resources Information Center

    Caley, Linda M.; Kramer, Charlotte; Robinson, Luther K.

    2005-01-01

    Fetal alcohol spectrum disorder (FASD) is a serious and widespread problem in this country. Positioned within the community with links to children, families, and healthcare systems, school nurses are a critical element in the prevention and treatment of those affected by fetal alcohol spectrum disorder. Although most school nurses are familiar…

  5. Fetal Alcohol Syndrome.

    ERIC Educational Resources Information Center

    Zerrer, Peggy

    The paper reviews Fetal Alcohol Syndrome (FAS), a series of effects seen in children whose mothers drink alcohol to excess during pregnancy. The identification of FAS and its recognition as a major health problem in need of prevention are traced. Characteristics of children with FAS are described and resultant growth retardation, abnormal physical…

  6. Alcoholism in Women.

    ERIC Educational Resources Information Center

    Mutzell, Sture

    1994-01-01

    Compared characteristics of female alcoholics receiving treatment with those of male alcoholics. Found male subjects had more psychosocial problems and had more contact with the child welfare authorities during their childhood than did the females. However, the females' offspring had had more such contact than the males' offspring. Socioeconomic…

  7. Women and Alcohol

    MedlinePlus

    ... with 5 percent alcohol content »» 5 ounces of wine with 12 percent alcohol content »» 1.5 ounces ... large cup of beer, an overpoured glass of wine, or a single mixed drink could contain much ...

  8. Cardiovascular effects of alcohol.

    PubMed Central

    Davidson, D M

    1989-01-01

    The effects of alcohol on the heart include modification of the risk of coronary artery disease, the development of alcoholic cardiomyopathy, exacerbation of conduction disorders, atrial and ventricular dysrhythmias, and an increased risk of hypertension, hemorrhagic stroke, infectious endocarditis, and fetal heart abnormalities. PMID:2686174

  9. Non-biodegradable biopolymers from renewable resources: perspectives and impacts.

    PubMed

    Steinbüchel, Alexander

    2005-12-01

    In recent years the biotechnological production of bulk biopolymers has focused on the synthesis of biodegradable polymers to replace their non-biodegradable counterparts derived from fossil resources. Examples include polyhydroxyalkanoates and polylactic acid, which act as substitutes for polyolefins. By contrast, the biotechnological production of non-biodegradable polymers from renewable resources has so far been scarcely considered, probably because this idea contradicts the paradigm that all natural compounds are biodegradable. Polythioesters, which were recently described as new biopolymers, do not follow this paradigm because although they are produced by bacteria, they are persistent to microbial degradation. Mankind has a need for both non-biodegradable and biodegradable polymers and methods to produce them from renewable resources will be of great value.

  10. Biodegradability of nitrogenous compounds under anaerobic conditions and its estimation.

    PubMed

    Hongwei, Yang; Zhanpeng, Jiang; Shaoqi, Shi

    2006-02-01

    The anaerobic biodegradability of 23 nitrogenous compounds, including nitrogenous heterocyclic compounds and aliphatic amines, was tested and assessed in integration. These nitrogenous compounds were classified into readily, partially, and poorly biodegradable compounds after calculation of their integrated assessment indices (IAIs), Rules for anaerobic biodegradation of these compounds were also drawn. Stepwise regression and backpropagation artificial neural network (BP-ANN) methods were applied to establish quantitative structure-biodegradability relationships (QSBRs) based on the assessment results. In QSBR models, three molecular structure descriptors-second-order molecular connectivity index (2chi(V3)chi(v)p), and energy of the highest occupied molecular orbital (EHOMO)--were included. After analysis of the sensitivity of variables in QSBR models, it was found that the key molecular structure descriptor affecting anaerobic biodegradability of nitrogenous compounds is EHOMO, which is directly proportional to the anaerobic biodegradability of nitrogenous compounds.

  11. Water-curable and biodegradable prepolymers.

    PubMed

    Kobayashi, H; Hyon, S H; Ikada, Y

    1991-12-01

    In an attempt to develop biodegradable polymers which can be shaped in situ and adhere to living tissues, we synthesized esterurethane prepolymers which can be cured upon contact with water in living tissues. First, D,L-lactide polymerization or D,L-lactide-epsilon-caprolactone (50:50) copolymerization was carried out using ethylene glycol or poly(ethylene glycol) as initiator to obtain hydroxyl-terminated biodegradable polyesters. They were then reacted with an excess of diisocyanate such as hexamethylene diisocyanate, toluylene diisocyanate, and diphenylmethane diisocyanate to introduce a reactive isocyanate group to both of the end groups of the polyesters. The isocyanate-terminated prepolymers could be cured in the presence of water and the cured polymers were degraded by hydrolysis both in vitro and in vivo. It was found that the presence of appropriate amounts of hydrophilic units in the main chain was essential for giving a high curing rate and a high degradation rate for the biodegradable urethane prepolymers. The tissue responses to the cured polymers were not severe.

  12. Bacterial production of the biodegradable plastics polyhydroxyalkanoates.

    PubMed

    Urtuvia, Viviana; Villegas, Pamela; González, Myriam; Seeger, Michael

    2014-09-01

    Petroleum-based plastics constitute a major environmental problem due to their low biodegradability and accumulation in various environments. Therefore, searching for novel biodegradable plastics is of increasing interest. Microbial polyesters known as polyhydroxyalkanoates (PHAs) are biodegradable plastics. Life cycle assessment indicates that PHB is more beneficial than petroleum-based plastics. In this report, bacterial production of PHAs and their industrial applications are reviewed and the synthesis of PHAs in Burkholderia xenovorans LB400 is described. PHAs are synthesized by a large number of microorganisms during unbalanced nutritional conditions. These polymers are accumulated as carbon and energy reserve in discrete granules in the bacterial cytoplasm. 3-hydroxybutyrate and 3-hydroxyvalerate are two main PHA units among 150 monomers that have been reported. B. xenovorans LB400 is a model bacterium for the degradation of polychlorobiphenyls and a wide range of aromatic compounds. A bioinformatic analysis of LB400 genome indicated the presence of pha genes encoding enzymes of pathways for PHA synthesis. This study showed that B. xenovorans LB400 synthesize PHAs under nutrient limitation. Staining with Sudan Black B indicated the production of PHAs by B. xenovorans LB400 colonies. The PHAs produced were characterized by GC-MS. Diverse substrates for the production of PHAs in strain LB400 were analyzed.

  13. Systematic approach for modeling tetrachloroethene biodegradation

    SciTech Connect

    Bagley, D.M.

    1998-11-01

    The anaerobic biodegradation of tetrachloroethene (PCE) is a reasonably well understood process. Specific organisms capable of using PCE as an electron acceptor for growth require the addition of an electron donor to remove PCE from contaminated ground waters. However, competition from other anaerobic microorganisms for added electron donor will influence the rate and completeness of PCE degradation. The approach developed here allows for the explicit modeling of PCE and byproduct biodegradation as a function of electron donor and byproduct concentrations, and the microbiological ecology of the system. The approach is general and can be easily modified for ready use with in situ ground-water models or ex situ reactor models. Simulations conducted with models developed from this approach show the sensitivity of PCE biodegradation to input parameter values, in particular initial biomass concentrations. Additionally, the dechlorination rate will be strongly influenced by the microbial ecology of the system. Finally, comparison with experimental acclimation results indicates that existing kinetic constants may not be generally applicable. Better techniques for measuring the biomass of specific organisms groups in mixed systems are required.

  14. IRIS Toxicological Review of Tert-Butyl Alcohol (Tert-Butanol) ...

    EPA Pesticide Factsheets

    On April 29, 2016, the Toxicological Review of tert-Butyl Alcohol (tert-Butanol) (Public Comment Draft) was released for public comment. The draft Toxicological Review and charge were reviewed internally by EPA and by other federal agencies and the Executive Office of the President during Step 3 (Interagency Science Consultation) before public release. As part of the IRIS process, all written interagency comments on IRIS assessments will be made publicly available. Accordingly, interagency comments with EPA's response and the interagency science consultation drafts of the IRIS Toxicological Review of tert-Butanol and charge to external peer reviewers are posted on this site. EPA is undertaking a new health assessment for t-butyl alcohol (tert-butanol) for the Integrated Risk Information System (IRIS). The outcome of this project will be a Toxicological Review and IRIS and IRIS Summary of TBA that will be entered on the IRIS database. IRIS is an EPA database containing Agency scientific positions on potential adverse human health effects that may result from chronic (or lifetime) exposure to chemicals in the environment. IRIS contains chemical-specific summaries of qualitative and quantitative health information to evaluate potential public health risks associated with environmental contaminants. The IRIS database is relied on for the development of risk assessments, site-specific environmental decisions, and rule making.

  15. Homocysteine and alcoholism.

    PubMed

    Bleich, S; Degner, D; Javaheripour, K; Kurth, C; Kornhuber, J

    2000-01-01

    Chronic alcohol consumption can induce alterations in the function and morphology of most if not all brain systems and structures. However, the exact mechanism of brain damage in alcoholics remains unknown. Partial recovery of brain function with abstinence suggests that a proportion of the deficits must be functional in origin (i.e. plastic changes of nerve cells) while neuronal loss from selected brain regions indicates permanent and irreversible damage. There is growing evidence that chronic alcoholism is associated with a derangement in the sulfur amino acid metabolism. Recently, it has been shown that excitatory amino acid (EAA) neurotransmitters and homocysteine levels are elevated in patients who underwent withdrawal from alcohol. Furthermore, it has been found that homocysteine induces neuronal cell damage by stimulating NMDA receptors as well as by producing free radicals. Homocysteine neurotoxicity via overstimulation of N-methyl-D-aspartate receptors may contribute to the pathogenesis of both brain shrinkage and withdrawal seizures linked to alcoholism.

  16. Alcoholic hepatitis: current management.

    PubMed

    Spengler, Erin K J; Dunkelberg, Jeffrey; Schey, Ron

    2014-10-01

    Alcoholic hepatitis is an acute manifestation of alcoholic liver disease with mortality as high as 40-50% in severe cases. Patients usually have a history of prolonged alcohol abuse with or without a known history of liver disease. Although there is significant range in severity at presentation, patients with severe alcoholic hepatitis typically present with anorexia, fatigue, fever, jaundice, and ascites. The use of either pentoxifylline or corticosteroids in those with severe disease (Maddrey's discriminate function >32) has significant mortality benefit. The addition of N-acetylcysteine to corticosteroids decreases the incidences of hepatorenal syndrome, infection, and short-term mortality, but does not appear to significantly affect 6-month mortality. Nutritional support with high-calorie, high-protein diet is recommended in all patients screening positive for malnutrition. Liver transplantation for a highly selected group of patients with severe alcoholic hepatitis may be an option in the future, but is not currently recommended or available at most transplant institutions.

  17. "Rational" management of dichlorophenols biodegradation by the microalga Scenedesmus obliquus.

    PubMed

    Papazi, Aikaterini; Kotzabasis, Kiriakos

    2013-01-01

    The microalga Scenedesmus obliquus exhibited the ability to biodegrade dichlorophenols (dcps) under specific autotrophic and mixotrophic conditions. According to their biodegradability, the dichlorophenols used can be separated into three distinct groups. Group I (2,4-dcp and 2,6 dcp - no meta-substitution) consisted of quite easily degraded dichlorophenols, since both chloride substituents are in less energetically demanding positions. Group II (2,3-dcp, 2,5-dcp and 3,4-dcp - one meta-chloride) was less susceptible to biodegradation, since one of the two substituents, the meta one, required higher energy for C-Cl-bond cleavage. Group III (3,5-dcp - two meta-chlorides) could not be biodegraded, since both chlorides possessed the most energy demanding positions. In general, when the dcp-toxicity exceeded a certain threshold, the microalga increased the energy offered for biodegradation and decreased the energy invested for biomass production. As a result, the biodegradation per cell volume of group II (higher toxicity) was higher, than group I (lower toxicity) and the biodegradation of dichlorophenols (higher toxicity) was higher than the corresponding monochlorophenols (lower toxicity). The participation of the photosynthetic apparatus and the respiratory mechanism of microalga to biodegrade the group I and the group II, highlighted different bioenergetic strategies for optimal management of the balance between dcp-toxicity, dcp-biodegradability and culture growth. Additionally, we took into consideration the possibility that the intermediates of each dcp-biodegradation pathway could influence differently the whole biodegradation procedures. For this reason, we tested all possible combinations of phenolic intermediates to check cometabolic interactions. The present contribution bring out the possibility of microalgae to operate as "smart" bioenergetic "machines", that have the ability to continuously "calculate" the energy reserves and "use" the most energetically

  18. Biodegradable Grease Technology for Future Army Combat Systems

    DTIC Science & Technology

    2004-12-01

    CHNS-932 Elemental Tester [LECO, 1992]. The sewage inoculum (i.e., bacteria, yeast , fungi) was carefully prepared from the mixed liquor...rapeseed oil) which bacteria like to eat due to its natural ester flavor may substantially improve the biodegradation process of a lubricant. Also...The BLG (2) with 20% rapeseed oil provides a similar biodegradation profile to rapeseed- BLG, while the biodegradation behavior of BLG (1) with 10

  19. Biodegradation of Alpha TNT and Its Production Isomers

    DTIC Science & Technology

    1974-07-01

    1 ^*"* **».-._ BIODEGRADATION OF ALPHA TNT ANT) ITS PRODUCTION ISOMERS Annual Report-U by: Richard W. Traxler University of Rhode Island...associated with the burning process. If these nitrobodies are found to be biodegradable , they could be rendered ecologically safe by biological...molecules are biodegradable by some microbial form whereas the truly recalcitrant molecules are found in broad classes of the synthetic organic compounds

  20. Development and validation of a scale of attitudes towards alcohol, alcoholism and alcoholics.

    PubMed

    Vargas, Divane de; Luis, Margarita Antonia Villar

    2008-01-01

    The objective of this study was the construction and validation of a scale that would measure the attitudes towards alcohol, alcoholism and the alcoholic, called the Scale of Attitudes Towards Alcohol, Alcoholism and the Alcoholic. The face and content validations, as well as the factor analysis of the data obtained in a preliminary test with 144 nursing students resulted in a scale consisting of 96 items, divided into 5 factors: Attitudes towards the alcoholic person: care and interpersonal relations; Etiology; Disease; Repercussions deriving from alcohol use/abuse; Alcoholic beverages. The general scale presented a consistency level of 0.90. The resulting instrument is concluded to be a reliable tool to evaluate attitudes towards alcohol, alcoholism and alcohol addicts.

  1. Accelerating Quinoline Biodegradation and Oxidation with Endogenous Electron Donors.

    PubMed

    Bai, Qi; Yang, Lihui; Li, Rongjie; Chen, Bin; Zhang, Lili; Zhang, Yongming; Rittmann, Bruce E

    2015-10-06

    Quinoline, a recalcitrant heterocyclic compound, is biodegraded by a series of reactions that begin with mono-oxygenations, which require an intracellular electron donor. Photolysis of quinoline can generate readily biodegradable products, such as oxalate, whose bio-oxidation can generate endogenous electron donors that ought to accelerate quinoline biodegradation and, ultimately, mineralization. To test this hypothesis, we compared three protocols for the biodegradation of quinoline: direct biodegradation (B), biodegradation after photolysis of 1 h (P1h+B) or 2 h (P2h+B), and biodegradation by adding oxalate commensurate to the amount generated from photolysis of 1 h (O1+B) or 2 h (O2+B). The experimental results show that P1h+B and P2h+B accelerated quinoline biodegradation by 19% and 50%, respectively, compared to B. Protocols O1+B and O2+B also gave 19% and 50% increases, respectively. During quinoline biodegradation, its first intermediate, 2-hydroxyquinoline, accumulated gradually in parallel to quinoline loss but declined once quinoline was depleted. Mono-oxygenation of 2-hydroxyquinoline competed with mono-oxygenation of quinoline, but the inhibition was relieved when extra electrons donors were added from oxalate, whether formed by UV photolysis or added exogenously. Rapid oxalate oxidation stimulated both mono-oxygenations, which accelerated the overall quinoline oxidation that provided the bulk of the electron donor.

  2. Critical evaluation of biodegradable polymers used in nanodrugs

    PubMed Central

    Marin, Edgar; Briceño, Maria Isabel; Caballero-George, Catherina

    2013-01-01

    Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed. PMID:23990720

  3. Functionalized synthetic biodegradable polymer scaffolds for tissue engineering.

    PubMed

    Liu, Xiaohua; Holzwarth, Jeremy M; Ma, Peter X

    2012-07-01

    Scaffolds (artificial ECMs) play a pivotal role in the process of regenerating tissues in 3D. Biodegradable synthetic polymers are the most widely used scaffolding materials. However, synthetic polymers usually lack the biological cues found in the natural extracellular matrix. Significant efforts have been made to synthesize biodegradable polymers with functional groups that are used to couple bioactive agents. Presenting bioactive agents on scaffolding surfaces is the most efficient way to elicit desired cell/material interactions. This paper reviews recent advancements in the development of functionalized biodegradable polymer scaffolds for tissue engineering, emphasizing the syntheses of functional biodegradable polymers, and surface modification of polymeric scaffolds.

  4. 78 FR 42529 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-16

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial Review....D., Scientific Review Administrator, National Institutes on Alcohol Abuse & Alcoholism,...

  5. 75 FR 38533 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-02

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Special Emphasis... Alcohol Abuse and Alcoholism, Office of Extramural Activities, Extramural Project Officer, 5635...

  6. 78 FR 42530 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-16

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial Review..., Ph.D., Scientific Review Officer, National Institute on Alcohol Abuse & Alcoholism,...

  7. 76 FR 77841 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-14

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial Review..., Ph.D., Scientific Review Officer, National Institute on Alcohol Abuse & Alcoholism,...

  8. 76 FR 78014 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-15

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial Review...., Scientific Review Administrator, National Institutes on Alcohol Abuse & Alcoholism, National Institutes...

  9. 75 FR 10808 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-03-09

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Special Emphasis... Officer, National Institute on Alcohol Abuse & Alcoholism, National Institutes of Health, 5635...

  10. 77 FR 22794 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial Review..., Ph.D., Scientific Review Administrator, National Institutes on Alcohol Abuse & Alcoholism...

  11. 77 FR 70171 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-23

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial Review... Review Officer, National Institute ] on Alcohol Abuse & Alcoholism, National Institutes of Health,...

  12. 76 FR 26308 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-06

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial Review..., Scientific Review Administrator, National Institutes On Alcohol Abuse & Alcoholism National, Institutes...

  13. 77 FR 22794 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-17

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism, Initial Review..., Ph.D., Scientific Review Officer, National Institute on Alcohol Abuse & Alcoholism,...

  14. 75 FR 57473 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-21

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Special Emphasis... Officer, National Institute on Alcohol Abuse and Alcoholism, Office of Extramural Activities,...

  15. Alcohol Alert: Link Between Stress and Alcohol

    MedlinePlus

    ... relate to alcohol use. 1 Racial and Ethnic Minority Stress Stress also can arise as a result of a person’s minority status, especially as it pertains to prejudice and discrimination. Such stress may range from mild (e.g., hassles such ...

  16. Supported metal catalysts for alcohol/sugar alcohol steam reforming

    SciTech Connect

    Davidson, Stephen; Zhang, He; Sun, Junming; Wang, Yong

    2014-08-21

    Despite extensive studies on hydrogen production via steam reforming of alcohols and sugar alcohols, catalysts typically suffer a variety of issues from poor hydrogen selectivity to rapid deactivation. Here, we summarize recent advances in fundamental understanding of functionality and structure of catalysts for alcohol/sugar alcohol steam reforming, and provide perspectives on further development required to design highly efficient steam reforming catalysts.

  17. Clinical pathology of alcohol.

    PubMed Central

    Marks, V

    1983-01-01

    There is good though not conclusive evidence that a small to modest average daily intake of alcohol--that is, 20-30 g/day is associated with increased longevity due mainly to a reduction in death from cardiovascular disease. Larger average daily alcohol intakes--especially those in excess of 60 g/day for men and 40 g/day for women--are associated with gradually increasing morbidity and mortality rates from a variety of diseases. Alcohol may be unrecognised as the cause of somatic disease, which can occur without overt psychosocial evidence of alcohol abuse, unless the index of suspicion is high and a thorough drink history obtained. Laboratory tests for the detection and/or confirmation of alcohol abuse are useful but subject to serious limitations being neither as sensitive nor specific as sometimes believed. The value of random blood and/or breath alcohol measurements, in outpatients, as an aid to diagnosis of alcohol-induced organic disease is probably not sufficiently appreciated and, though relatively insensitive, is highly specific. PMID:6339563

  18. Alcoholism: genes and mechanisms.

    PubMed

    Oroszi, Gabor; Goldman, David

    2004-12-01

    Alcoholism is a chronic relapsing/remitting disease that is frequently unrecognized and untreated, in part because of the partial efficacy of treatment. Only approximately one-third of patients remain abstinent and one-third have fully relapsed 1 year after withdrawal from alcohol, with treated patients doing substantially better than untreated [1]. The partial effectiveness of strategies for prevention and treatment, and variation in clinical course and side effects, represent a challenge and an opportunity to better understand the neurobiology of addiction. The strong heritability of alcoholism suggests the existence of inherited functional variants of genes that alter the metabolism of alcohol and variants of other genes that alter the neurobiologies of reward, executive cognitive function, anxiety/dysphoria, and neuronal plasticity. Each of these neurobiologies has been identified as a critical domain in the addictions. Functional alleles that alter alcoholism-related intermediate phenotypes include common alcohol dehydrogenase 1B and aldehyde dehydrogenase 2 variants that cause the aversive flushing reaction; catechol-O-methyltransferase (COMT) Val158Met leading to differences in three aspects of neurobiology: executive cognitive function, stress/anxiety response, and opioid function; opioid receptor micro1 (OPRM1) Asn40Asp, which may serve as a gatekeeper molecule in the action of naltrexone, a drug used in alcoholism treatment; and HTTLPR, which alters serotonin transporter function and appears to affect stress response and anxiety/dysphoria, which are factors relevant to initial vulnerability, the process of addiction, and relapse.

  19. Alcohol-related symptoms in heterogeneous families of hospitalized alcoholics.

    PubMed

    Gilligan, S B; Reich, T; Cloninger, C R

    1988-10-01

    Heterogeneity in the clinical symptoms of alcohol abuse was examined in 243 men and 305 women from families of hospitalized alcoholics, who had demonstrated different patterns of inheritance of susceptibility to alcoholism. Discriminant analysis was utilized to identify nine alcoholic symptoms that distinguished male relatives of alcoholic men from those of alcoholic women. Inability to abstain from alcohol, fighting and reckless driving while intoxicated, and alcohol treatment other than Alcoholics Anonymous were more prevalent in families of male probands. Male relatives of female probands experienced later onset of loss of control over drinking associated with benders, and cirrhosis and feelings of guilt. Female relatives of alcoholic men and women showed a marked predominance of the latter (Type 1) features, whereas male relatives had different clinical features, depending on the associated mode of inheritance.

  20. Magnetic biodegradable Fe3O4/CS/PVA nanofibrous membranes for bone regeneration.

    PubMed

    Wei, Yan; Zhang, Xuehui; Song, Yu; Han, Bing; Hu, Xiaoyang; Wang, Xinzhi; Lin, Yuanhua; Deng, Xuliang

    2011-10-01

    In recent years, interest in magnetic biomimetic scaffolds for tissue engineering has increased considerably. The aim of this study is to develop magnetic biodegradable fibrous materials with potential use in bone regeneration. Magnetic biodegradable Fe(3)O(4)/chitosan (CS)/poly vinyl alcohol (PVA) nanofibrous membranes were achieved by electrospinning with average fiber diameters ranging from 230 to 380 nm and porosity of 83.9-85.1%. The influences of polymer concentration, applied voltage and Fe(3)O(4) nanoparticles loading on the fabrication of nanofibers were investigated. The polymer concentration of 4.5 wt%, applied voltage of 20 kV and Fe(3)O(4) nanoparticles loading of lower than 5 wt% could produce homogeneous, smooth and continuous Fe(3)O(4)/CS/PVA nanofibrous membranes. X-ray diffraction (XRD) data confirmed that the crystalline structure of the Fe(3)O(4), CS and PVA were maintained during electrospinning process. Fourier transform infrared spectroscopy (FT-IR) demonstrated that the Fe(3)O(4) loading up to 5 wt% did not change the functional groups of CS/PVA greatly. Transmission electron microscopy (TEM) showed islets of Fe(3)O(4) nanoparticles evenly distributed in the fibers. Weak ferrimagnetic behaviors of membranes were revealed by vibrating sample magnetometer (VSM) test. Tensile test exhibited Young's modulus of membranes that were gradually enhanced with the increase of Fe(3)O(4) nanoparticles loading, while ultimate tensile stress and ultimate strain were slightly reduced by Fe(3)O(4) nanoparticles loading of 5%. Additionally, MG63 human osteoblast-like cells were seeded on the magnetic nanofibrous membranes to evaluate their bone biocompatibility. Cell growth dynamics according to MTT assay and scanning electron microscopy (SEM) observation exhibited good cell adhesion and proliferation, suggesting that this magnetic biodegradable Fe(3)O(4)/CS/PVA nanofibrous membranes can be one of promising biomaterials for facilitation of osteogenesis.

  1. Alcohol Policies on College Campuses.

    ERIC Educational Resources Information Center

    Mitchell, Rebecca J.; Toomey, Traci L.; Erickson, Darin

    2005-01-01

    State and local alcohol policies can minimize opportunities for people to use alcohol, thereby reducing consumption and alcohol-related problems. Little is known, however, about the prevalence of campus policies aimed at reducing college students' alcohol use and related problems. The authors surveyed school administrators in Minnesota and…

  2. An entropy spring model for the Young's modulus change of biodegradable polymers during biodegradation.

    PubMed

    Wang, Ying; Han, Xiaoxiao; Pan, Jingzhe; Sinka, Csaba

    2010-01-01

    This paper presents a model for the change in Young's modulus of biodegradable polymers due to hydrolysis cleavage of the polymer chains. The model is based on the entropy spring theory for amorphous polymers. It is assumed that isolated polymer chain cleavage and very short polymer chains do not affect the entropy change in a linear biodegradable polymer during its deformation. It is then possible to relate the Young's modulus to the average molecular weight in a computer simulated hydrolysis process of polymer chain sessions. The experimental data obtained by Tsuji [Tsuji, H., 2002. Autocatalytic hydrolysis of amorphous-made polylactides: Effects of L-lactide content, tacticity, and enantiomeric polymer blending. Polymers 43, 1789-1796] for poly(L-lactic acid) and poly(D-lactic acid) are examined using the model. It is shown that the model can provide a common thread through Tsuji's experimental data. A further numerical case study demonstrates that the Young's modulus obtained using very thin samples, such as those obtained by Tsuji, cannot be directly used to calculate the load carried by a device made of the same polymer but of various thicknesses. This is because the Young's modulus varies significantly in a biodegradable device due to the heterogeneous nature of the hydrolysis reaction. The governing equations for biodegradation and the relation between the Young's modulus and average molecular weight can be combined to calculate the load transfer from a degrading device to a healing bone.

  3. Isomer-specific biodegradation of nonylphenol in an activated sludge bioreactor and structure-biodegradability relationship.

    PubMed

    Lu, Zhijiang; Reif, Rubén; Gan, Jay

    2015-01-01

    Nonylphenol (NP), one of the priority hazardous substances, is in fact a mixture of numerous isomers. It is inconclusive whether or not biodegradation during wastewater treatment process is isomer-specific, leading to the environmental release of NP in different isomer profiles. In this study, we evaluated the isomer selectivity of 19 NP isomers in a laboratory-scale continuous flow conventional activated sludge bioreactor under various operational conditions. The removal efficiency of NP isomers ranged from 90 to 99%, depending on the operational conditions and isomer structures. Isomer selective biodegradation resulted in the increase of composition of recalcitrant isomers, such as, NP₁₉₃a/b, NP₁₁₀a and NP₁₉₄ in the effluent. Moreover, biodegradability was related to the bulkiness of α-substituents and followed α-dimethyl > α-ethyl-α-methyl > α-methyl-α-n-propyl > α-iso-propyl-α-methyl. Steric effect index, a quantitative descriptor of steric hindrance, was linearly correlated with residues of NP isomers in the effluent (R² = 0.76). Decrease of temperature to 10 °C decreased the overall biodegradability and also enhanced the relative enrichment of recalcitrant isomers. These findings suggest that isomer compositions of NP entering the environment may be different from those in technical mixtures and that isomeric selectivity should be taken into account to better understand the occurrence, fate, and ecological risks of NP.

  4. Biodegradable and bioactive CGP/PVA film for fungal growth inhibition.

    PubMed

    Silva, Bárbara Dumas S; Ulhoa, Cirano J; Batista, Karla A; Di Medeiros, Maria Carolina; Da Silva Filho, Rômulo Roosevelt; Yamashita, Fabio; Fernandes, Kátia F

    2012-07-01

    In this study, chitinolytic enzymes produced by Trichoderma asperellum were immobilized on a biodegradable film manufactured with a blend of cashew gum polysaccharide (CGP) and polyvinyl alcohol (PVA), and tested as a fungal growth inhibitor. The film was produced by casting a blend of CGP and PVA solution on glass molds. The CGP/PVA film showed 68% water solubility, tensile strength of 23.7 MPa, 187.2% elongation and 52% of mass loss after 90 days in soil. The presence of T-CWD enzymes immobilized by adsorption or covalent attachment resulted in effective inhibition of fungal growth. Sclerotinia sclerotiorum was the most sensitive organism, followed by Aspergillus niger and Penicillium sp. SEM micrograph showed that the presence of immobilized T-CWD enzymes on CGP/PVA film produced morphological modifications on vegetative and germinative structures of the microorganisms, particularly hyphae disruption and changes of spores shape.

  5. Lipase entrapment in PVA/Chitosan biodegradable film for reactor coatings.

    PubMed

    Batista, Karla A; Lopes, Flavio Marques; Yamashita, Fabio; Fernandes, Kátia Flávia

    2013-04-01

    This study reports the development and characterization of novel biodegradable film, based on chitosan and polyvinyl alcohol containing lipase entrapped. The films showed a thickness of 70.4 and 79 μm to PVA/Chitosan and PVA/Chitosan/Lipase, respectively. The entrapment of lipase in PVA/Chitosan film resulted in increasing of 69.4% tensile strength (TS), and 52.4% of elongation. SEM images showed the formation of a continuous film, without pores or cracks. The lipase entrapment efficiency was estimated in 92% and the films were repeatedly used for 25 hydrolytic cycles, maintaining 62% of initial activity. The PVA/Chitosan/Lipase film was used for olive oil hydrolysis of high performance. These results indicate that PVA/Chitosan/Lipase is a promising material for biotechnology applications such as triacylglycerol hydrolysis and biodiesel production.

  6. Aerobic biodegradation of two fluorotelomer sulfonamide-based aqueous film forming foam components produces perfluoroalkyl carboxylates.

    PubMed

    D'Agostino, Lisa A; Mabury, Scott A

    2017-02-01

    The biodegradation of 2 common fluorotelomer surfactants used in aqueous film forming foams (AFFFs), 6:2 fluorotelomer sulfonamide alkylamine (FTAA) and 6:2 fluorotelomer sulfonamide alkylbetaine (FTAB), was investigated over 109 d with aerobic wastewater treatment plant (WWTP) sludge. Results show that biodegradation of 6:2 FTAA and 6:2 FTAB produces 6:2 fluorotelomer alcohol (FTOH), 6:2 fluorotelomer carboxylic acid (FTCA), 6:2 fluorotelomer unsaturated carboxylic acid (FTUCA), 5:3 FTCA, and short chain perfluoroalkyl carboxylates (PFCAs). Additional degradation products included 6:2 fluorotelomer sulfonamide (FTSAm), which was a major degradation product in the presence of either active or sterilized sludge, while 6:2 fluorotelomer sulfonate (FTSA) production was measured with sterilized sludge only. Six additional degradation products were tentatively identified by quadrupole time-of-flight mass spectrometry (qTOF-MS) and were attributed to N-dealkylation and oxidation of 6:2 FTAA. This article is protected by copyright. All rights reserved.

  7. Synthesis and characterization of highly-magnetic biodegradable poly(D,L-lactide-co-glycolide) nanospheres.

    SciTech Connect

    Liu, X.; Kaminski, M. D.; Chen, H.; Torno, M.; Taylor, L.; Rosengart, A. J.; Univ. of Chicago

    2007-05-14

    The objective of this study was to develop high magnetization, biodegradable/biocompatible polymer-coated magnetic nanospheres for biomedical applications. Magnetic spheres were prepared by a modified single oil-in-water emulsion-solvent evaporation method utilizing highly-concentrated hydrophobic magnetite and poly(d,l lactide-co-glycolide) (PLGA). Hydrophobic magnetite prepared using oleic acid exhibited high magnetite concentrations (84 wt.%) and good miscibility with biopolymer solvents to form a stable oily suspension. The oily suspension was then emulsified within an aqueous solution containing poly(vinyl alcohol). After rapid evaporation of the organic solvent, we obtained solid magnetic nanospheres. We characterized these spheres in terms of external morphology, microstructure, size and zeta potential, magnetite content and distribution within the nanospheres, and magnetic properties. The results showed good encapsulation where the magnetite distorted the smooth surface morphology only at the highest magnetite concentrations. The mean diameter was 360-370 nm with polydispersity indices of 0.12-0.20. We obtained high magnetite content (40-60%) and high magnetization (26-40 emu/g). The high magnetization properties were obtained while leaving sufficient polymer to retain drugs making these biodegradable spheres suitable as a potential platform for the design of magnetically-guided drug delivery and other in vivo biomagnetic applications.

  8. Scalable method to produce biodegradable nanoparticles that rapidly penetrate human mucus.

    PubMed

    Xu, Qingguo; Boylan, Nicholas J; Cai, Shutian; Miao, Bolong; Patel, Himatkumar; Hanes, Justin

    2013-09-10

    Mucus typically traps and rapidly removes foreign particles from the airways, gastrointestinal tract, nasopharynx, female reproductive tract and the surface of the eye. Nanoparticles capable of rapid penetration through mucus can potentially avoid rapid clearance, and open significant opportunities for controlled drug delivery at mucosal surfaces. Here, we report an industrially scalable emulsification method to produce biodegradable mucus-penetrating particles (MPP). The emulsification of diblock copolymers of poly(lactic-co-glycolic acid) and polyethylene glycol (PLGA-PEG) using low molecular weight (MW) emulsifiers forms dense brush PEG coatings on nanoparticles that allow rapid nanoparticle penetration through fresh undiluted human mucus. In comparison, conventional high MW emulsifiers, such as polyvinyl alcohol (PVA), interrupts the PEG coating on nanoparticles, resulting in their immobilization in mucus owing to adhesive interactions with mucus mesh elements. PLGA-PEG nanoparticles with a wide range of PEG MW (1, 2, 5, and 10 kDa), prepared by the emulsification method using low MW emulsifiers, all rapidly penetrated mucus. A range of drugs, from hydrophobic small molecules to hydrophilic large biologics, can be efficiently loaded into biodegradable MPP using the method described. This readily scalable method should facilitate the production of MPP products for mucosal drug delivery, as well as potentially longer-circulating particles following intravenous administration.

  9. [Prevention of alcohol dependence].

    PubMed

    Trova, A C; Paparrigopoulos, Th; Liappas, I; Ginieri-Coccossis, M

    2015-01-01

    With the exception of cardiovascular diseases, no other medical condition causes more serious dysfunction or premature deaths than alcohol-related problems. Research results indicate that alcohol dependent individuals present an exceptionally poor level of quality of life. This is an outcome that highlights the necessity of planning and implementing preventive interventions on biological, psychological or social level, to be provided to individuals who make alcohol abuse, as well as to their families. Preventive interventions can be considered on three levels of prevention: (a) primary prevention, which is focused on the protection of healthy individuals from alcohol abuse and dependence, and may be provided on a universal, selective or indicated level, (b) secondary prevention, which aims at the prevention of deterioration regarding alcoholic dependence and relapse, in the cases of individuals already diagnosed with the condition and (c) tertiary prevention, which is focused at minimizing deterioration of functioning in chronically sufferers from alcoholic dependence. The term "quaternary prevention" can be used for the prevention of relapse. As for primary prevention, interventions focus on assessing the risk of falling into problematic use, enhancing protective factors and providing information and health education in general. These interventions can be delivered in schools or in places of work and recreation for young people. In this context, various programs have been applied in different countries, including Greece with positive results (Preventure, Alcolocks, LST, SFP, Alcohol Ignition Interlock Device). Secondary prevention includes counseling and structured help with the delivery of programs in schools and in high risk groups for alcohol dependence (SAP, LST). These programs aim at the development of alcohol refusal skills and behaviors, the adoption of models of behaviors resisting alcohol use, as well as reinforcement of general social skills. In the

  10. Alcohol and Cancer Risk

    MedlinePlus

    ... oral cavity (excluding the lips), pharynx (throat), and larynx (voice box) ( 4 ). People who consume 50 or ... developing cancers of the oral cavity , pharynx (throat), larynx , and esophagus than people who use either alcohol ...

  11. Alcohol advertising and youth.

    PubMed

    Martin, Susan E; Snyder, Leslie B; Hamilton, Mark; Fleming-Milici, Fran; Slater, Michael D; Stacy, Alan; Chen, Meng-Jinn; Grube, Joel W

    2002-06-01

    This article presents the proceedings of a symposium at the 2001 Research Society on Alcoholism meeting in Montreal, Canada. The symposium was organized and chaired by Joel W. Grube. The presentations and presenters were (1) Introduction and background, by Susan E. Martin; (2) The effect of alcohol ads on youth 15-26 years old, by Leslie Snyder, Mark Hamilton, Fran Fleming-Milici, and Michael D. Slater; (3) A comparison of exposure to alcohol advertising and drinking behavior in elementary versus middle school children, by Phyllis L. Ellickson and Rebecca L. Collins; (4) USC health and advertising project: assessment study on alcohol advertisement memory and exposure, by Alan Stacy; and (5) TV beer and soft drink advertising: what young people like and what effects? by Meng-Jinn Chen and Joel W. Grube.

  12. Weight loss and alcohol

    MedlinePlus

    ... eye on how drinking affects your eating habits. Calories and Portions Count So, how much can you ... dieting. Keep in mind that alcohol has empty calories. This means it has a lot of calories ( ...

  13. Alcoholic cardiomyopathy: Pathophysiologic insights

    PubMed Central

    Piano, Mariann R.; Phillips, Shane A.

    2014-01-01

    Alcoholic cardiomyopathy is a specific heart muscle disease found in individuals with a history of long-term heavy alcohol consumption. Alcoholic cardiomyopathy is associated with a number of adverse histological, cellular, and structural changes within the myocardium. Several mechanisms are implicated in mediating the adverse effects of ethanol, including the generation of oxidative stress, apoptotic cell death, impaired mitochondrial bioenergetics/stress, derangements in fatty acid metabolism and transport, and accelerated protein catabolism. In this review, we discuss the evidence for such mechanisms and present the potential importance of drinking patterns, genetic susceptibility, nutritional factors, race, and sex. The purpose of this review is to provide a mechanistic paradigm for future research in the area of alcoholic cardiomyopathy. PMID:24671642

  14. Alcohol Facts and Statistics

    MedlinePlus

    ... http://www.ncbi.nlm.nih.gov/pubmed/15201626 . Definitions Alcohol Use Disorder (AUD): AUD is a medical ... or more days in the past month. NIAAA’s Definition of Drinking at Low Risk for Developing AUD: ...

  15. Analysis of Alcohols.

    ERIC Educational Resources Information Center

    McCullough, Brother Thomas

    1984-01-01

    Presents a novel approach to identification of unknown alcohols using experimental measurements of boiling point and viscosity which are easily obtained without expensive equipment of instrumentation. Provides instructions for preparing capillary viscometer, listing special hints for obtaining good results. (JM)

  16. Alcohol use disorder

    MedlinePlus

    ... be a combination of a person's: Genes Environment Psychology, such as being impulsive or having low self- ... using alcohol. This is called abstinence. Having strong social and family support can help make it easier ...

  17. Alcohol Use Disorder

    MedlinePlus

    ... as irreversible dementia, if not promptly treated. Birth defects. Alcohol use during pregnancy may cause miscarriage. It ... as depression or anxiety? Do you use recreational drugs? You're likely to start by seeing your ...

  18. Inpatient alcohol withdrawal syndrome.

    PubMed

    Monte-Secades, R; Rabuñal-Rey, R; Guerrero-Sande, H

    2015-03-01

    A 55-year-old man was admitted for a femur fracture; an alcohol fetor was noted on admission. The following day, the patient began to experience tremors and nervousness. Intravenous haloperidol was administered. Shortly afterwards, the patient experienced two generalized seizures and then began to experience delirium and uncontrollable agitation. The patient was diagnosed with alcohol withdrawal syndrome; high doses of intravenous midazolam were prescribed and infused. A few hours later, the patient presented signs of respiratory depression, requiring a transfer to the intensive care unit. After a review of the medical history, it was determined that the patient had been admitted on 3 previous occasions due to alcohol withdrawal and had progressed to delirium tremens after experiencing seizures. Can the risk of alcohol withdrawal syndrome and the need for prophylactic treatment be assessed on admission? Were appropriate monitoring and treatment measures employed? Would it have been possible to change his outcome?

  19. Biodegradation of polyester polyurethane by Aspergillus tubingensis.

    PubMed

    Khan, Sehroon; Nadir, Sadia; Shah, Zia Ullah; Shah, Aamer Ali; Karunarathna, Samantha C; Xu, Jianchu; Khan, Afsar; Munir, Shahzad; Hasan, Fariha

    2017-03-15

    The xenobiotic nature and lack of degradability of polymeric materials has resulted in vast levels of environmental pollution and numerous health hazards. Different strategies have been developed and still more research is being in progress to reduce the impact of these polymeric materials. This work aimed to isolate and characterize polyester polyurethane (PU) degrading fungi from the soil of a general city waste disposal site in Islamabad, Pakistan. A novel PU degrading fungus was isolated from soil and identified as Aspergillus tubingensis on the basis of colony morphology, macro- and micro-morphology, molecular and phylogenetic analyses. The PU degrading ability of the fungus was tested in three different ways in the presence of 2% glucose: (a) on SDA agar plate, (b) in liquid MSM, and (c) after burial in soil. Our results indicated that this strain of A. tubingensis was capable of degrading PU. Using scanning electron microscopy (SEM), we were able to visually confirm that the mycelium of A. tubingensis colonized the PU material, causing surface degradation and scarring. The formation or breakage of chemical bonds during the biodegradation process of PU was confirmed using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy. The biodegradation of PU was higher when plate culture method was employed, followed by the liquid culture method and soil burial technique. Notably, after two months in liquid medium, the PU film was totally degraded into smaller pieces. Based on a comprehensive literature search, it can be stated that this is the first report showing A. tubingensis capable of degrading PU. This work provides insight into the role of A. tubingensis towards solving the dilemma of PU wastes through biodegradation.

  20. Enhanced biodegradation of creosote-contaminated soil

    SciTech Connect

    Carriere, P.P.E.; Mesania, F.A.

    1995-12-31

    Bioremediation, a viable option for treatment of creosote-contaminated soil, can be enhanced by the use of surfactant. A study was conducted to investigate the effect of a non-ionic surfactant, Triton X-100, on biodegradation of creosote-contaminated soil. Abiotic soil desorption experiments were performed to determine the kinetics of release of selected polynuclear aromatic hydrocarbon (PAH) compounds. Respirometric experiments were also conducted to evaluate the effect of nonionic surfactant on biodegradation. The N-Con system respirometer was used to monitor the oxygen uptake by the microorganisms. The abiotic experiments results indicated that the addition of surfactant to soil/water systems increased the desorption of PAH compounds. It was also observed that the desorption rate of PAH compounds depended on their molecular weight. The 3- and 4-ring PAH compounds showed higher and faster desorption rates than the 5- and 6-ring PAHs. The respirometric experiments indicated that an increase in soil contamination level from 112.5 to 771.8 mg/kg showed an increase in oxygen uptake. But for a soil contamination level of 1,102.5 mg/kg, the oxygen uptake was similar to the contamination level of 771.8 mg/kg. This might be due to toxicity by the surfactant or the solubilized PAHs at high concentration or interference with contaminant transport into the cell or to reversible physical-chemical interferences with the activity of enzymes involved in the PAH degradation. The increase in PAH availability to the microorganisms in the aqueous phase produced an increase in oxygen consumption that is proportional to the biodegradation of organic compounds.

  1. SCREENING OF BACTERIAL PRODUCTS FOR THEIR CRUDE OIL BIODEGRADATION EFFECTIVENESS

    EPA Science Inventory

    Although petroleum hydrocarbons have been known to be biodegradable for decades (1-5), use of microbial cultures to enhance natural biodegradation (bioaugmentation) has met with limited success (6-10). Despite the paucity of controlled field studies demonstrating the effectivene...

  2. Wet air oxidation induced enhanced biodegradability of distillery effluent.

    PubMed

    Malik, S N; Saratchandra, T; Tembhekar, P D; Padoley, K V; Mudliar, S L; Mudliar, S N

    2014-04-01

    The present study reports the feasibility of Wet Air Oxidation (WAO) as a pretreatment option for enhanced biodegradation of complex distillery effluent. Initially, the distillery effluent was pretreated by WAO at different process conditions (pressure, temperature and time) to facilitate enhancement in the biodegradability index (BI = BOD5: COD ratio). The biodegradability of WAO pretreated effluent was evaluated by subjecting it to aerobic biodegradation and anaerobic followed by aerobic biodegradation. Aerobic biodegradation of pretreated effluent with enhanced biodegradability index (BI = 0.4-0.8) showed enhanced COD reduction of up to 67.7%, whereas the untreated effluent (BI = 0.17) indicated poor COD reduction of only 22.5%. Anaerobic followed by aerobic biodegradation of pretreated effluent has shown up to 87.9% COD reduction, while the untreated effluent has shown only 43.1% COD reduction. Bio-kinetic parameters also confirmed the increased rate of bio-oxidation at enhanced BIs. The results indicate that the WAO pretreatment facilitates enhanced bio-oxidation/bio-degradation of complex effluents like the distillery spent wash.

  3. Biodegradation of Petroleum Hydrocarbon in the Vadose Zone

    EPA Science Inventory

    There are two major impediments to a better understanding of the influence of biodegradation on the risk of intrusion of petroleum vapors. We describe the contribution of biodegradation as an attenuation factor between the source and the receptor. The use of attenuation factors...

  4. KINETICS OF ETHANOL BIODEGRADATION UNDER METHANOGENIC CONDITIONS IN GASOLINE SPILLS

    EPA Science Inventory

    Ethanol is commonly used as a fuel oxygenate. A concern has been raised that biodegradation of ethanol from a spill of gasoline may inhibit the natural biodegradation of fuel hydrocarbons, including benzene. Ethanol is miscible in water, and ethanol is readily metabolized by mi...

  5. Electrophysiological studies in alcoholism

    PubMed Central

    Blackstock, Eileen; Rushworth, Geoffrey; Gath, Dennis

    1972-01-01

    Using a range of electrophysiological techniques, it has been possible to demonstrate impaired function in smaller calibre motor fibres and in distal large cutaneous sensory nerve fibres in both alcoholic patients without neuropathy and in those alcoholics with clinical manifestations of peripheral nerve disease. Evidence of more proximal involvement of Ia sensory fibres was obtained, but in the majority of our patients, large motor fibres functioned normally. The nature of the underlying pathological process is discussed. Images PMID:4338445

  6. Alcoholism: Current Marker Research

    DTIC Science & Technology

    1984-03-01

    genetically determined characteristics such as color blindness and blood type . GENETIC MARKER STUDIES In 1966 Dr. Cruz-Coke and Dr. Varela reported that...and recovery from severe alcoholism symptoms. ■󈧒:584-587) Blood - typing marker studies have produced similar mixed results. One study published in...1959 showed a high correlation among 939 alcoholics and blood type A. (20:4 60-4 61) A similar study in 1973 reported no blood type distribution

  7. Biodegradable and Renal Clearable Inorganic Nanoparticles

    PubMed Central

    Ehlerding, Emily B.

    2015-01-01

    Personalized treatment plans for cancer therapy have been at the forefront of oncology research for many years. With the advent of many novel nanoplatforms, this goal is closer to realization today than ever before. Inorganic nanoparticles hold immense potential in the field of nano‐oncology, but have considerable toxicity concerns that have limited their translation to date. In this review, an overview of emerging biologically safe inorganic nanoplatforms is provided, along with considerations of the challenges that need to be overcome for cancer theranostics with inorganic nanoparticles to become a reality. The clinical and preclinical studies of both biodegradable and renal clearable inorganic nanoparticles are discussed, along with their implications. PMID:27429897

  8. Molecular basis of biodegradation of chloroaromatic compounds

    SciTech Connect

    Sangodkar, U.M.X.; Aldrich, T.L.; Haugland, T.L.; Johnson, R.A.; Rothmel, R.K.

    1989-01-01

    Chlorinated aromatic hydrocarbons are widely used in industry and agriculture and comprise the bulk of environmental pollutants. Although simple aromatic compounds are biodegradable by a variety of degradative pathways, their halogenated counterparts are more resistant to bacterial attack and often necessitate evolution of novel pathways. An understanding of such evolutionary processes is essential for developing genetically improved strains capable of mineralizing highly chlorinated compounds. The article provides an overview of the genetic aspects of dissimilation of chloroaromatic compounds and discusses the potential of gene manipulation to promote enhanced evolution of the degradative pathways.

  9. Biosynthesis and biodegradation of wood components

    SciTech Connect

    Higuchi, T.

    1985-01-01

    A textbook containing 22 chapters by various authors covers the structure of wood, the localization of polysaccharides and lignins in wood cell walls, metabolism and synthetic function of cambial tissue, cell organelles and their function in the biosynthesis of cell wall components, biosynthesis of plant cell wall polysaccharides, lignin, cutin, suberin and associated waxes, phenolic acids and monolignols, quinones, flavonoids, tannins, stilbenes and terpenoid wood extractives, the occurrence of extractives, the metabolism of phenolic acids, wood degradation by micro-organisms and fungi, and biodegradation of cellulose, hemicelluloses, lignin, and aromatic extractives of wood. An index is included.

  10. Biodegradation of petroleum hydrocarbons in hypersaline environments

    PubMed Central

    Martins, Luiz Fernando; Peixoto, Raquel Silva

    2012-01-01

    Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review. PMID:24031900

  11. Biodegradation of petroleum hydrocarbons in hypersaline environments.

    PubMed

    Martins, Luiz Fernando; Peixoto, Raquel Silva

    2012-07-01

    Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  12. Effect of surfactants at low concentrations on the desorption and biodegradation of sorbed aromatic compounds in soil

    SciTech Connect

    Aronstein, B.N.; Calvillo, Y.M.; Alexander, M. )

    1991-10-01

    A study was conducted to determine the effect of low concentrations of surfactants on the biodegradation of sorbed aromatic compounds in soil. The nonionic alcohol ethoxylate surfactants Alfonic 810-60 and Novel II 1412-56 increased the extent of desorption of phenanthrene from a mineral soil. Alfonic 810-60 enhanced desorption of biphenyl from this soil at one concentration tested, but Novel II 1412-56 did not. Less than 0.01{per thousand} of the added phenanthrene and biphenyl was present in solution after their introduction into an organic soil, and the surfactants did not promote desorption. The two surfactants at 10 {mu}g/g of soil markedly increased the extent of biodegradation of phenanthrene in both the mineral and the organic soil; the stimulation was greater in the organic soil. Biphenyl mineralization in the mineral soil was not affected by either surfactant, but biodegradation in the organic soil was enhanced by Alfonic 810-60 at 100 {mu}g/g. The authors suggest that surfactants at low concentrations may promote the mineralization of sorbed aromatic compounds in polluted soils, even when surfactant-induced desorption is not appreciable.

  13. Stress and Alcohol

    PubMed Central

    Keyes, KM.; Hatzenbuehler, ML.; Grant, Bridget F.; Hasin, Deborah S.

    2012-01-01

    Exposure to stress often is psychologically distressing. The impact of stress on alcohol use and the risk of alcohol use disorders (AUDs) depends on the type, timing during the life course, duration, and severity of the stress experienced. Four important categories of stressors that can influence alcohol consumption are general life stress, catastrophic/fateful stress, childhood maltreatment, and minority stress. General life stressors, including divorce and job loss, increase the risk for AUDs. Exposure to terrorism or other disasters causes population-level increases in overall alcohol consumption but little increase in the incidence of AUDs. However, individuals with a history of AUDs are more likely to drink to cope with the traumatic event. Early onset of drinking in adolescence, as well as adult AUDs, are more common among people who experience childhood maltreatment. Finally, both perceptions and objective indicators of discrimination are associated with alcohol use and AUDs among racial/ethnic and sexual minorities. These observations demonstrate that exposure to stress in many forms is related to subsequent alcohol consumption and AUDs. However, many areas of this research remain to be studied, including greater attention to the role of various stressors in the course of AUDs and potential risk moderators when individuals are exposed to stressors. PMID:23584105

  14. Neuropathology of alcoholism.

    PubMed

    Sutherland, Greg T; Sheedy, Donna; Kril, Jillian J

    2014-01-01

    Chronic alcohol consumption results in structural changes to the brain. In alcoholics without coexisting thiamine deficiency or liver disease this is largely restricted to a loss of white-matter volume. When it occurs, neuronal loss is limited in anatomic distribution and only detected with quantitative techniques. This relative paucity of neurodegeneration is reflected in studies of gene and protein expression in postmortem brain where findings are subtle and discordant between studies. In alcoholics with coexisting pathologies, neuronal loss is more marked and affects a wider range of anatomic regions, especially subcortical nuclei. Although this more widespread damage may reflect a more severe drinking history, there is evidence linking thiamine deficiency and the consequences of liver disease to the pathogenesis of alcohol-related brain damage. Furthermore, a range of other factors, such as cigarette smoking and mood disorders, that are common in alcoholics, have the potential to influence studies of brain pathology and should be considered in further studies of the neuropathology of alcoholism.

  15. Monitoring aromatic hydrocarbon biodegradation by functional marker genes.

    PubMed

    Nyyssönen, Mari; Piskonen, Reetta; Itävaara, Merja

    2008-07-01

    The development of biological treatment technologies for contaminated environments requires tools for obtaining direct information about the biodegradation of specific contaminants. The potential of functional gene array analysis to monitor changes in the amount of functional marker genes as indicators of contaminant biodegradation was investigated. A prototype functional gene array was developed for targeting key functions in the biodegradation of naphthalene, toluene and xylenes. Internal standard probe based normalization was introduced to facilitate comparison across multiple samples. Coupled with one-colour hybridization, the signal normalization improved the consistency among replicate hybridizations resulting in better discrimination for the differences in the amount of target DNA. During the naphthalene biodegradation in a PAH-contaminated soil slurry microcosm, the normalized hybridization signals in naphthalene catabolic gene probes were in good agreement with the amount of naphthalene-degradation genes and the production of 14CO2. Gene arrays provide efficient means for monitoring of contaminant biodegradation in the environment.

  16. Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

    SciTech Connect

    McCarty, Perry L.; Spormann, Alfred M.; Criddle, Craig S.

    2001-06-01

    The anaerobic biodegradation of chlorinated solvents is of great interest both for natural attenuation and for engineered remediation of these hazardous contaminants in groundwater. Compounds to be studied are carbon tetrachloride (CT) and the chlorinated ethenes, tetrachloroethene (PCE), trichloroethene (TCE) cis-1,2-dichloroethene (cDCE), and vinyl chloride (VC). The chlorinated solvents often are present as dense non-aqueous-phase liquids (DNAPLs), which are difficult to remove. Biodegradation of DNAPLs was previously thought not possible because of toxicity, but recent evidence indicates that under the right conditions, biodegradation is possible. Anaerobic biodegradation of DNAPLs is the major subject of this research. The specific objectives of this multi-investigator effort are: (1) Evaluate the potential for chlorinated solvent biodegradation near DNAPLs, (2) Provide a molecular understanding of the biological mechanisms involved, (3) Determine cellular components involved in carbon tetrachloride transformation by Pseudomonas stutzeri strain KC without chloroform formation.

  17. Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

    SciTech Connect

    McCarty, Perry L.; Spormann, Alfred M.; Criddle, Craig S.

    2002-06-01

    The anaerobic biodegradation of chlorinated solvents is of great interest both for natural attenuation and for engineered remediation of these hazardous contaminants in groundwater. Compounds to be studied are carbon tetrachloride (CT) and the chlorinated ethenes, tetrachloroethene (PCE), trichloroethene (TCE) cis-1,2-dichloroethene (cDCE), and vinyl chloride (VC). The chlorinated solvents often are present as dense non-aqueous-phase liquids (DNAPLs), which are difficult to remove. Biodegradation of DNAPLs was previously thought not possible because of toxicity, but recent evidence indicates that under the right conditions, biodegradation is possible. Anaerobic biodegradation of DNAPLs is the major subject of this research. The specific objectives of this multi-investigator effort are: (1) Evaluate the potential for chlorinated solvent biodegradation near DNAPLs, (2) Provide a molecular understanding of the biological mechanisms involved, (3) Determine cellular components involved in carbon tetrachloride transformation by Pseudomonas stutzeri strain KC without chloroform formation.

  18. Biodegradation of Chlorinated Solvents: Reactions near DNAPL and Enzyme Function

    SciTech Connect

    McCarty, Perry L.; Spormann, Alfred M.; Criddle, Craig S.

    2003-06-01

    The anaerobic biodegradation of chlorinated solvents is of great interest both for natural attenuation and for engineered remediation of these hazardous contaminants in groundwater. Compounds to be studied are carbon tetrachloride (CT) and the chlorinated ethenes, tetrachloroethene (PCE), trichloroethene (TCE) cis-1,2-dichloroethene (cDCE), and vinyl chloride (VC). The chlorinated solvents often are present as dense non-aqueous-phase liquids (DNAPLs), which are difficult to remove. Biodegradation of DNAPLs was previously thought not possible because of toxicity, but recent evidence indicates that under the right conditions, biodegradation is possible. Anaerobic biodegradation of DNAPLs is the major subject of this research. The specific objectives of this multi-investigator effort are: (1) Evaluate the potential for chlorinated solvent biodegradation near DNAPLs, (2) Provide a molecular understanding of the biological mechanisms involved, (3) Determine cellular components involved in carbon tetrachloride transformation by Pseudomonas stutzeri strain KC without chloroform formation.

  19. Porous Biodegradable Metals for Hard Tissue Scaffolds: A Review

    PubMed Central

    Yusop, A. H.; Bakir, A. A.; Shaharom, N. A.; Abdul Kadir, M. R.; Hermawan, H.

    2012-01-01

    Scaffolds have been utilized in tissue regeneration to facilitate the formation and maturation of new tissues or organs where a balance between temporary mechanical support and mass transport (degradation and cell growth) is ideally achieved. Polymers have been widely chosen as tissue scaffolding material having a good combination of biodegradability, biocompatibility, and porous structure. Metals that can degrade in physiological environment, namely, biodegradable metals, are proposed as potential materials for hard tissue scaffolding where biodegradable polymers are often considered as having poor mechanical properties. Biodegradable metal scaffolds have showed interesting mechanical property that was close to that of human bone with tailored degradation behaviour. The current promising fabrication technique for making scaffolds, such as computation-aided solid free-form method, can be easily applied to metals. With further optimization in topologically ordered porosity design exploiting material property and fabrication technique, porous biodegradable metals could be the potential materials for making hard tissue scaffolds. PMID:22919393

  20. [Progress on biodegradation of polylactic acid--a review].

    PubMed

    Li, Fan; Wang, Sha; Liu, Weifeng; Chen, Guanjun

    2008-02-01

    Polylactic acid is a high molecular-weight polyester made from renewable resources such as corn or starch. It is a promising biodegradable plastic due to its mechanical properties, biocompatibility and biodegradability. To achieve natural recycling of polylactic acid, relative microorganisms and the underlying mechanisms in the biodegradation has become an important issue in biodegradable materials. Up to date, most isolated microbes capable of degrading polylactic acid belong to actinomycetes. Proteases secreted by these microorganisms are responsible for the degradation. However, subtle differences exist between these polylactic acid degrading enzymes and typical proteases with respect to substrate binding and catalysis. Amino acids relative to catalysis are postulated to be highly plastic allowing their catalytic hydrolysis of polylactic acid. In this paper we reviewed current studies on biodegradation of polylactic acid concerning its microbial, enzymatic reactions and the possible mechanisms. We also discussed the probability of biologically recycling PLA by applying highly efficient strains and enzymes.

  1. Thermal stability of biodegradable plasmonic nanoclusters in photoacoustic imaging.

    PubMed

    Yoon, Soon Joon; Murthy, Avinash; Johnston, Keith P; Sokolov, Konstantin V; Emelianov, Stanislav Y

    2012-12-31

    The photothermal stability of plasmonic nanoparticles is critically important to perform reliable photoacoustic imaging and photothermal therapy. Recently, biodegradable nanoclusters composed of sub-5 nm primary gold particles and a biodegradable polymer have been reported as clinically-translatable contrast agents for photoacoustic imaging. After cellular internalization, the nanoclusters degrade into 5 nm primary particles for efficient excretion from the body. In this paper, three different sizes of biodegradable nanoclusters were synthesized and the optical properties and photothermal stability of the nanoclusters were investigated and compared to that of gold nanorods. The results of our study indicate that 40 nm and 80 nm biodegradable nanoclusters demonstrate higher photothermal stability compared to gold nanorods. Furthermore, 40 nm nanoclusters produce higher photoacoustic signal than gold nanorods at a given concentration of gold. Therefore, the biodegradable plasmonic nanoclusters can be effectively used for photoacoustic imaging and photothermal therapy.

  2. Biodegradation of PuEDTA and Impacts on Pu Mobility

    SciTech Connect

    Xun, Luying; Bolton, Jr., Harvey

    2001-06-01

    Ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA) are synthetic chelating agents, which can form strong water-soluble complexes with radionuclides and metals and has been used to decontaminate and process nuclear materials. Synthetic chelating agents were co-disposed with radionuclides (e.g., 60Co, Pu) and heavy metals enhancing their transport in the subsurface. An understanding of EDTA biodegradation is essential to help mitigate enhanced radionuclide transport by EDTA. The objective of this research is to develop fundamental data on factors that govern the biodegradation of radionuclide-EDTA. These factors include the dominant EDTA aqueous species, the biodegradation of various metal-EDTA complexes, the uptake of various metal-EDTA complexes into the cell, the distribution and mobility of the radionuclide during and after EDTA biodegradation, and the enzymology and genetics of EDTA biodegradation.

  3. Biodegradable plastic agricultural mulches and key features of microbial degradation.

    PubMed

    Brodhagen, Marion; Peyron, Mark; Miles, Carol; Inglis, Debra Ann

    2015-02-01

    The development of biodegradable plastic mulch films for use in agriculture has been ongoing for decades. These films consist of mixtures of polymers with various additives. As a result, their physical and chemical properties differ from those of the pure polymers often used for in vitro enzymatic and microbial degradation studies, raising questions about the biodegradation capability of mulch films. Currently, standards exist for the biodegradation of plastics in composting conditions but not in soil. Biodegradation in soil or compost depends on a complex synergy of biological and abiotic degradative processes. This review discusses the physicochemical and structural properties of biodegradable plastic mulches, examines their potential for on-site decomposition in light of site-to-site variance due to environmental and biological conditions, and considers the potential for long-term effects on agroecosystem sustainability and functionality.

  4. Thermal stability of biodegradable plasmonic nanoclusters in photoacoustic imaging

    PubMed Central

    Yoon, Soon Joon; Murthy, Avinash; Johnston, Keith P.; Sokolov, Konstantin V.; Emelianov, Stanislav Y.

    2012-01-01

    The photothermal stability of plasmonic nanoparticles is critically important to perform reliable photoacoustic imaging and photothermal therapy. Recently, biodegradable nanoclusters composed of sub-5 nm primary gold particles and a biodegradable polymer have been reported as clinically-translatable contrast agents for photoacoustic imaging. After cellular internalization, the nanoclusters degrade into 5 nm primary particles for efficient excretion from the body. In this paper, three different sizes of biodegradable nanoclusters were synthesized and the optical properties and photothermal stability of the nanoclusters were investigated and compared to that of gold nanorods. The results of our study indicate that 40 nm and 80 nm biodegradable nanoclusters demonstrate higher photothermal stability compared to gold nanorods. Furthermore, 40 nm nanoclusters produce higher photoacoustic signal than gold nanorods at a given concentration of gold. Therefore, the biodegradable plasmonic nanoclusters can be effectively used for photoacoustic imaging and photothermal therapy. PMID:23388774

  5. Evaluation of artificial intelligence based models for chemical biodegradability prediction.

    PubMed

    Baker, James R; Gamberger, Dragan; Mihelcic, James R; Sabljić, Aleksandar

    2004-12-31

    This study presents a review of biodegradability modeling efforts including a detailed assessment of two models developed using an artificial intelligence based methodology. Validation results for these models using an independent, quality reviewed database, demonstrate that the models perform well when compared to another commonly used biodegradability model, against the same data. The ability of models induced by an artificial intelligence methodology to accommodate complex interactions in detailed systems, and the demonstrated reliability of the approach evaluated by this study, indicate that the methodology may have application in broadening the scope of biodegradability models. Given adequate data for biodegradability of chemicals under environmental conditions, this may allow for the development of future models that include such things as surface interface impacts on biodegradability for example.

  6. Enhanced biodegradation of hydrocarbons in soil by microbial biosurfactant, sophorolipid.

    PubMed

    Kang, Seok-Whan; Kim, Young-Bum; Shin, Jae-Dong; Kim, Eun-Ki

    2010-03-01

    Effectiveness of a microbial biosurfactant, sophorolipid, was evaluated in washing and biodegradation of model hydrocarbons and crude oil in soil. Thirty percent of 2-methylnaphthalene was effectively washed and solubilized with 10 g/L of sophorolipid with similar or higher efficiency than that of commercial surfactants. Addition of sophorolipid in soil increased biodegradation of model compounds: 2-methylnaphthalene (95% degradation in 2 days), hexadecane (97%, 6 days), and pristane (85%, 6 days). Also, effective biodegradation method of crude oil in soil was observed by the addition of sophorolipid, resulting in 80% biodegradation of saturates and 72% aromatics in 8 weeks. These results showed the potentials of the microbial biosurfactant, sophorolipid, as an effective surfactant for soil washing and as an in situ biodegradation enhancer.

  7. Comparing the effects of various fuel alcohols on the natural attenuation of Benzene Plumes using a general substrate interaction model

    NASA Astrophysics Data System (ADS)

    Gomez, Diego E.; Alvarez, Pedro J. J.

    2010-04-01

    The effects of five fuel alcohols (methanol, ethanol, 1-propanol, iso-butanol and n-butanol) on the natural attenuation of benzene were compared using a previously developed numerical model (General Substrate Interaction Module — GSIM) and a probabilistic sensitivity analysis. Simulations with a 30 gal dissolving LNAPL (light non-aqueous phase liquid) source consisting of a range of gasoline blends (10% and 85% v:v alcohol content) suggest that all fuel alcohols can hinder the natural attenuation of benzene, due mainly to accelerated depletion of dissolved oxygen and a decrease in the specific degradation rate for benzene (due to catabolite repression and metabolic flux dilution). Simulations for blends with 10% alcohol, assuming a homogeneous sandy aquifer, inferred maximum benzene plume elongations (relative to a regular gasoline release) of 26% for ethanol, 47% for iso-butanol, 147% for methanol, 188% for 1-propanol, and 265% for n-butanol. The corresponding elongation percentages for blends with 85% alcohol were generally smaller (i.e., 25%, 54%, 135%, 163%, and 181%, respectively), reflecting a lower content of benzene in the simulated release. Benzene plume elongation and longevity were more pronounced in the presence of alcohols that biodegrade slower (e.g., propanol and n-butanol), forming longer and more persistent alcohol plumes. Conversely, ethanol and iso-butanol exhibited the lowest potential to hinder the natural attenuation of benzene, illustrating the significant effect that a small difference in chemical structure (e.g., isomers) can have on biodegradation. Overall, simulations were highly sensitive to site-specific biokinetic coefficients for alcohol degradation, which forewarns against generalizations about the level of impact of specific fuel alcohols on benzene plume dynamics.

  8. Perspectives on the neuroscience of alcohol from the National Institute on Alcohol Abuse and Alcoholism.

    PubMed

    Reilly, Matthew T; Noronha, Antonio; Warren, Kenneth

    2014-01-01

    Mounting evidence over the last 40 years clearly indicates that alcoholism (alcohol dependence) is a disorder of the brain. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) has taken significant steps to advance research into the neuroscience of alcohol. The Division of Neuroscience and Behavior (DNB) was formed within NIAAA in 2002 to oversee, fund, and direct all research areas that examine the effects of alcohol on the brain, the genetic underpinnings of alcohol dependence, the neuroadaptations resulting from excessive alcohol consumption, advanced behavioral models of the various stages of the addiction cycle, and preclinical medications development. This research portfolio has produced important discoveries in the etiology, treatment, and prevention of alcohol abuse and dependence. Several of these salient discoveries are highlighted and future areas of neuroscience research on alcohol are presented.

  9. 27 CFR 4.36 - Alcoholic content.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Alcoholic content. 4.36 Section 4.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL LABELING AND ADVERTISING OF WINE Labeling Requirements for Wine § 4.36 Alcoholic content. (a) Alcoholic content shall...

  10. 27 CFR 4.36 - Alcoholic content.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Alcoholic content. 4.36 Section 4.36 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL LABELING AND ADVERTISING OF WINE Labeling Requirements for Wine § 4.36 Alcoholic content. (a) Alcoholic content shall...

  11. 27 CFR 7.71 - Alcoholic content.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Alcoholic content. 7.71 Section 7.71 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL LABELING AND ADVERTISING OF MALT BEVERAGES Interim Regulations for Alcoholic Content Statements § 7.71 Alcoholic content....

  12. 27 CFR 7.71 - Alcoholic content.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Alcoholic content. 7.71 Section 7.71 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY ALCOHOL LABELING AND ADVERTISING OF MALT BEVERAGES Interim Regulations for Alcoholic Content Statements § 7.71 Alcoholic content....

  13. An 'inherent' biodegradability test for oil products: description and results of an international ring test. CONCAWE Biodegradation Task Force.

    PubMed

    Battersby, N S; Ciccognani, D; Evans, M R; King, D; Painter, H A; Peterson, D R; Starkey, M

    1999-06-01

    Current test guidelines for assessing 'inherent' (potential) biodegradability were designed for water-soluble, organic compounds of low volatility and are unsuitable for most oil products. It was against this background, that CONCAWE (the oil companies' European organisation for environment, health and safety) formed a task force to develop a standard test protocol for assessing the 'inherent' biodegradability of oil products.

  14. Oxidation and biodegradation of polyethylene films containing pro-oxidantadditives: Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation on the oxidation and biodegradation of linear low density poly (ethylene) PE-LLD films containing pro-oxidant were examined. To achieve oxidation and degradation, films were first exposed to the sunlight for 93 days du...

  15. Etiologic heterogeneity in alcoholism.

    PubMed

    Gilligan, S B; Reich, T; Cloninger, C R

    1987-01-01

    Etiologic heterogeneity in alcohol abuse was evaluated in 195 extended pedigrees, comprising 288 nuclear families of 140 male and 55 female Caucasian American hospitalized alcoholics. Previous adoption studies in Sweden demonstrated differential heritability of two patterns of alcohol abuse in men: type-2 alcoholism exhibited early onset of abuse associated with criminal behavior, while type-1 abuse began at a later age, uncomplicated by antisocial traits. Alcohol abuse in female Swedish adoptees was relatively homogeneous and similar to the late-onset, type-1 abuse. The notion of etiologic heterogeneity, as suggested by the Stockholm Adoption Studies, was examined in the American pedigrees by contrasting the models of familial transmission of susceptibility to alcoholism obtained via segregation analyses of families of male versus female probands. Families of male probands demonstrated significant familial resemblance, accounted for by a multifactorial-polygenic background in addition to a major (gene) effect. In contrast, familial resemblance in the pedigrees of female probands was attributed solely to a multifactorial-polygenic effect. We considered whether some families of male alcoholics were similar to families of female probands, who expressed type-1 abuse predominantly. Pedigrees of male probands were separated in two groups: (1) "female-like" families had a better likelihood for the model obtained for families of female probands than the one for families of all male probands, (2) "male-like" families had a better likelihood for the model of familial transmission describing families of all male probands. A statistically significant difference in the pattern of familial transmission was observed between the "male-like" and "female-like" groups. Discriminant function analysis of alcohol-related symptoms showed that the familial subtypes differed in clinical features as well. Alcohol abuse by male relatives in "male-like" families was characterized by the

  16. Immunological Response to Biodegradable Magnesium Implants

    NASA Astrophysics Data System (ADS)

    Pichler, Karin; Fischerauer, Stefan; Ferlic, Peter; Martinelli, Elisabeth; Brezinsek, Hans-Peter; Uggowitzer, Peter J.; Löffler, Jörg F.; Weinberg, Annelie-Martina

    2014-04-01

    The use of biodegradable magnesium implants in pediatric trauma surgery would render surgical interventions for implant removal after tissue healing unnecessary, thereby preventing stress to the children and reducing therapy costs. In this study, we report on the immunological response to biodegradable magnesium implants—as an important aspect in evaluating biocompatibility—tested in a growing rat model. The focus of this study was to investigate the response of the innate immune system to either fast or slow degrading magnesium pins, which were implanted into the femoral bones of 5-week-old rats. The main alloying element of the fast-degrading alloy (ZX50) was Zn, while it was Y in the slow-degrading implant (WZ21). Our results demonstrate that degrading magnesium implants beneficially influence the immune system, especially in the first postoperative weeks but also during tissue healing and early bone remodeling. However, rodents with WZ21 pins showed a slightly decreased phagocytic ability during bone remodeling when the degradation rate reached its maximum. This may be due to the high release rate of the rare earth-element yttrium, which is potentially toxic. From our results we conclude that magnesium implants have a beneficial effect on the innate immune system but that there are some concerns regarding the use of yttrium-alloyed magnesium implants, especially in pediatric patients.

  17. Nitroaromatic compounds, from synthesis to biodegradation.

    PubMed

    Ju, Kou-San; Parales, Rebecca E

    2010-06-01

    Nitroaromatic compounds are relatively rare in nature and have been introduced into the environment mainly by human activities. This important class of industrial chemicals is widely used in the synthesis of many diverse products, including dyes, polymers, pesticides, and explosives. Unfortunately, their extensive use has led to environmental contamination of soil and groundwater. The nitro group, which provides chemical and functional diversity in these molecules, also contributes to the recalcitrance of these compounds to biodegradation. The electron-withdrawing nature of the nitro group, in concert with the stability of the benzene ring, makes nitroaromatic compounds resistant to oxidative degradation. Recalcitrance is further compounded by their acute toxicity, mutagenicity, and easy reduction into carcinogenic aromatic amines. Nitroaromatic compounds are hazardous to human health and are registered on the U.S. Environmental Protection Agency's list of priority pollutants for environmental remediation. Although the majority of these compounds are synthetic in nature, microorganisms in contaminated environments have rapidly adapted to their presence by evolving new biodegradation pathways that take advantage of them as sources of carbon, nitrogen, and energy. This review provides an overview of the synthesis of both man-made and biogenic nitroaromatic compounds, the bacteria that have been identified to grow on and completely mineralize nitroaromatic compounds, and the pathways that are present in these strains. The possible evolutionary origins of the newly evolved pathways are also discussed.

  18. Optimization of low ring polycylic aromatic biodegradation

    NASA Astrophysics Data System (ADS)

    Othman, N.; Abdul-Talib, S.; Tay, C. C.

    2016-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are recalcitrance and persistence that finally turn into problematic environmental contaminants. Microbial degradation is considered to be the primary mechanism of PAHs removal from the environment due to its organic criteria. This study is carried out to optimize degradation process of low ring PAHs. Bacteria used in this study was isolated from sludge collected from Kolej Mawar, Universiti Teknologi MARA, Shah Alam, Selangor. Working condition namely, substrate concentration, bacteria concentration, pH and temperature were optimized. PAHs in the liquid sample was extracted by using solid phase microextractio equipped with a 7 µm polydimethylsiloxane (PDMS) SPME fibr. Removal of PAHs were assessed by measuring PAHs concentration using GC-FID. Results from the optimization study of biodegradation indicated that maximum rate of PAHs removal occurred at 100 mgL-1 of PAHs, 10% bacteria concentration, pH 7.0 and 30°C. These working condition had proved the effectiveness of using bacteria in biodegradation process of PAHs.

  19. Nitroaromatic Compounds, from Synthesis to Biodegradation

    PubMed Central

    Ju, Kou-San; Parales, Rebecca E.

    2010-01-01

    Summary: Nitroaromatic compounds are relatively rare in nature and have been introduced into the environment mainly by human activities. This important class of industrial chemicals is widely used in the synthesis of many diverse products, including dyes, polymers, pesticides, and explosives. Unfortunately, their extensive use has led to environmental contamination of soil and groundwater. The nitro group, which provides chemical and functional diversity in these molecules, also contributes to the recalcitrance of these compounds to biodegradation. The electron-withdrawing nature of the nitro group, in concert with the stability of the benzene ring, makes nitroaromatic compounds resistant to oxidative degradation. Recalcitrance is further compounded by their acute toxicity, mutagenicity, and easy reduction into carcinogenic aromatic amines. Nitroaromatic compounds are hazardous to human health and are registered on the U.S. Environmental Protection Agency's list of priority pollutants for environmental remediation. Although the majority of these compounds are synthetic in nature, microorganisms in contaminated environments have rapidly adapted to their presence by evolving new biodegradation pathways that take advantage of them as sources of carbon, nitrogen, and energy. This review provides an overview of the synthesis of both man-made and biogenic nitroaromatic compounds, the bacteria that have been identified to grow on and completely mineralize nitroaromatic compounds, and the pathways that are present in these strains. The possible evolutionary origins of the newly evolved pathways are also discussed. PMID:20508249

  20. Improving alachlor biodegradability by ferrate oxidation.

    PubMed

    Zhu, Jian-Hang; Yan, Xi-Luan; Liu, Ye; Zhang, Bao

    2006-07-31

    Alachlor can be recalcitrant when present at high concentrations in wastewater. Ferrate oxidation was used as a pretreatment to improve its biodegradability and was evaluated by monitoring alachlor elimination and removal of COD(Cr) (chemical oxygen demand determined by potassium dichromate) during the oxidation process up to a value compatible with biological treatment. Ferrate oxidation resulted in elimination of alachlor followed by degradation of its intermediates. High pH suppressed alachlor removal and COD(Cr) removal due to the low redox potential of ferrate ions. Although alachlor can be totally eliminated within 10 min under optimized conditions (alachlor, 40 mg l(-1); ferrate:alachlor molar ratio, 2; and pH 7.0), its complete mineralization cannot be achieved by ferrate oxidation alone. Alachlor solution treated by ferrate for 10 min inhibited an up-flow biotreatment with activated sludge. The biodegradability of ferrate-pretreated solution improved when the treatment was increased to 20 min, at the point of which BOD(5)/COD(Cr) ratio of the treated solution was increased to 0.87 from 0.35 after 10 min treatment. Under optimized conditions, ferrate oxidation for 20 min resulted in total elimination of alachlor, partial removal of COD(Cr) and the ferrate-treated solution could be effectively treated by the up-flow activated sludge process.

  1. Endothelial Cellular Responses to Biodegradable Metal Zinc.

    PubMed

    Ma, Jun; Zhao, Nan; Zhu, Donghui

    Biodegradable zinc (Zn) metals, a new generation of biomaterials, have attracted much attention due to their excellent biodegradability, bioabsorbability, and adaptability to tissue regeneration. Compared with magnesium (Mg) and iron (Fe), Zn exhibits better corrosion and mechanical behaviors in orthopedic and stent applications. After implantation, Zn containing material will slowly degrade, and Zn ions (Zn(2+)) will be released to the surrounding tissue. For stent applications, the local Zn(2+)concentration near endothelial tissue/cells could be high. However, it is unclear how endothelia will respond to such high concentrations of Zn(2+), which is pivotal to vascular remodeling and regeneration. Here, we evaluated the short-term cellular behaviors of primary human coronary artery endothelial cells (HCECs) exposed to a concentration gradient (0-140 μM) of extracellular Zn(2+). Zn(2+) had an interesting biphasic effect on cell viability, proliferation, spreading, and migration. Generally, low concentrations of Zn(2+) promoted viability, proliferation, adhesion, and migration, while high concentrations of Zn(2+) had opposite effects. For gene expression profiles, the most affected functional genes were related to cell adhesion, cell injury, cell growth, angiogenesis, inflammation, vessel tone, and coagulation. These results provide helpful information and guidance for Zn-based alloy design as well as the controlled release of Zn(2+)in stent and other related medical applications.

  2. Biodegradable polymer optical fiber (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Zhang, Chenji; Kalaba, Surge; Shan, Dingying; Xu, Kaitian; Yang, Jian; Liu, Zhiwen

    2016-10-01

    Biocompatible and even biodegradable polymers have unique advantages in various biomedical applications. Recent years, photonic devices fabricated using biocompatible polymers have been widely studied. In this work, we manufactured an optical fiber using biodegradable polymer POC and POMC. This step index optical fiber is flexible and easy to handle. Light was coupled into this polymer fiber by directly using objective. The fiber has a good light guiding property and an approximate loss of 2db/cm. Due to the two layer structure, our fiber is able to support applications inside biological tissue. Apart from remarkable optical performance, our fiber was also found capable of performing imaging. By measuring the impulse response of this multimode polymer fiber and using the linear inversion algorithm, concept proving experiments were completed. Images input into our fiber were able to be retrieved from the intensity distribution of the light at the output end. Experiment result proves the capability of our optical fiber to be used as a fiber endoscopy no needs to remove.

  3. Monitoring Biodegradation of Magnesium Implants with Sensors

    NASA Astrophysics Data System (ADS)

    Zhao, Daoli; Wang, Tingting; Guo, Xuefei; Kuhlmann, Julia; Doepke, Amos; Dong, Zhongyun; Shanov, Vesselin N.; Heineman, William R.

    2016-04-01

    Magnesium and its alloys exhibit properties such as high strength, light weight, and in vivo corrosion that make them promising candidates for the development of biodegradable metallic implant materials for bone repair, stents and other medical applications. Sensors have been used to monitor the corrosion of magnesium and its alloys by measuring the concentrations of the following corrosion products: magnesium ions, hydroxyl ions and hydrogen gas. The corrosion characterization system with home-made capillary pH and Mg2+ microsensors has been developed for real-time detection of magnesium corrosion in vitro. A hydrogen gas sensor was used to monitor the corrosion of magnesium by measuring the concentration of the hydrogen gas reaction product in vivo. The high permeability of hydrogen through skin allows transdermal monitoring of the biodegradation of a magnesium alloy implanted beneath the skin by detecting hydrogen gas at the skin surface. The sensor was used to map hydrogen concentration in the vicinity of an implanted magnesium alloy.

  4. Biodegradation of glycol ethers in soil

    SciTech Connect

    Gonsior, S.J.; West, R.J.

    1995-08-01

    Because of the widespread use of glycol ethers in applications ranging from consumer products to use as chemical intermediates, there is a need to better understand the fate of these compounds in the environment. Soil biodegradation studies were conducted for three propylene glycol ethers: 1-methoxy-2-propanol, 1-phenoxy-2-propanol, and 1-methoxy-2-propanol acetate. The test compounds were labeled with carbon-14 at either the methoxy or phenoxy substituents. Biodegradation of the three compounds was observed in two sandy loam soils. The time required for disappearance of 50% of the test compounds ranged from < 1 d at 0.2 ppm (w/w) to <7 d at 107 ppm. Degradation rates were slower in a sandy soil, reflecting the lower concentration of microorganisms present. No significant accumulation of intermediate products was observed, and ultimate yields of {sup 14}CO{sub 2} were in the range of 40 to 65% of the initial concentration. Results indicated that the glycol ethers were degraded in a variety of soils under aerobic conditions.

  5. Wood biodegradation in laboratory-scale landfills.

    PubMed

    Wang, Xiaoming; Padgett, Jennifer M; De la Cruz, Florentino B; Barlaz, Morton A

    2011-08-15

    The objective of this research was to characterize the anaerobic biodegradability of major wood products in municipal waste by measuring methane yields, decay rates, the extent of carbohydrate decomposition, carbon storage, and leachate toxicity. Tests were conducted in triplicate 8 L reactors operated to obtain maximum yields. Measured methane yields for red oak, eucalyptus, spruce, radiata pine, plywood (PW), oriented strand board (OSB) from hardwood (HW) and softwood (SW), particleboard (PB) and medium-density fiberboard (MDF) were 32.5, 0, 7.5, 0.5, 6.3, 84.5, 0, 5.6, and 4.6 mL CH(4) dry g(-1), respectively. The red oak, a HW, exhibited greater decomposition than either SW (spruce and radiata), a trend that was also measured for the OSB-HW relative to OSB-SW. However, the eucalyptus (HW) exhibited toxicity. Thus, wood species have unique methane yields that should be considered in the development of national inventories of methane production and carbon storage. The current assumption of uniform biodegradability is not appropriate. The ammonia release from urea formaldehyde as present in PB and MDF could contribute to ammonia in landfill leachate. Using the extent of carbon conversion measured in this research, 0-19.9%, predicted methane production from a wood mixture using the Intergovernmental Panel for Climate Change waste model is only 7.9% of that predicted using the 50% carbon conversion default.

  6. Multivalent Induction of Biodegradative Threonine Deaminase

    PubMed Central

    Yui, Yoshiki; Watanabe, Yasuyoshi; Ito, Seiji; Shizuta, Yutaka; Hayaishi, Osamu

    1977-01-01

    To determine the inducer(s) of the biodegradative threonine deaminase in Escherichia coli, the effects of various amino acids on the synthesis of this enzyme were investigated. The complex medium used hitherto for the enzyme induction can be completely replaced by a synthetic medium composed of 18 natural amino acids. In this synthetic medium, the omission of each of the seven amino acids threonine, serine, aspartic acid, methionine, valine, leucine, and arginine resulted in the greatest loss of enzyme formation. These seven amino acids did not significantly influence the uptake of other amino acids into the cells. Furthermore, they did not stimulate the conversion of inactive enzyme into an active form, since they did not affect the enzyme level in cells in which protein synthesis was inhibited by chloramphenicol. Threonine, serine, aspartic acid, and methionine failed to stimulate enzyme production in cells in which messenger ribonucleic acid synthesis was arrested by rifampin, whereas valine, leucine, and arginine stimulated enzyme synthesis under the same conditions. Therefore, the first four amino acids appear to act as inducers of the biodegradative threonine deaminase in E. coli and the last three amino acids appear to be amplifiers of enzyme production. The term “multivalent induction” has been proposed for this type of induction, i.e., enzyme induction only by the simultaneous presence of several amino acids. PMID:334736

  7. WOMEN ALCOHOLICS : ARE THEY DIFFERENT FROM MEN ALCOHOLICS ?

    PubMed Central

    Selvaraj, V.; Suveera, Prasad; Ashok, M.V.; Appaya, M.P.

    1997-01-01

    Women alcoholics seeking psychiatric help have been increasing steadily over the years. The data on this subgroup however, is limited. Eighteen women alcoholics who presented to us over one year have been compared to twenty-eight men alcoholics who presented to us over one calendar month. Gender differences in the functions and effects of problem drinking were found. Men and women alcoholics differed in marital and occupational status, initiating and maintaining factors for drinking, course of alcoholism and alcohol related damage. PMID:21584094

  8. Alcohol expectancies, alcohol use, and hostility as longitudinal predictors of alcohol-related aggression.

    PubMed

    Kachadourian, Lorig K; Homish, Gregory G; Quigley, Brian M; Leonard, Kenneth E

    2012-09-01

    The direct and interactive effects of alcohol expectancies for aggression, dispositional hostility, and heavy alcohol consumption on alcohol-related physical aggression were examined across the first four years of marriage in a sample of 634 newlywed couples. For husbands, alcohol aggression expectancies predicted increases in alcohol-related aggression; across husbands and wives, however, aggression expectancies were not found to interact with hostility or alcohol consumption to predict physical aggression. Consistent with previous research, hostility and alcohol consumption interacted with each other to predict alcohol-related aggression. Specifically, for both husbands and wives high in dispositional hostility, heavy alcohol consumption was positively associated with the occurrence of alcohol-related aggression; for those low in dispositional hostility, however, there was no association between alcohol consumption and alcohol-related aggression. Findings are contrasted with previous longitudinal research on alcohol aggression expectancies and physical aggression in married couples. The article discusses the extent to which findings may vary depending on whether expectancies are assessed in relation to alcohol's effect on one's own behavior versus alcohol's effect on others' behavior.

  9. Biodegradative Activities of Selected Environmental Fungi on a Polyester Polyurethane Varnish and Polyether Polyurethane Foams

    PubMed Central

    Álvarez-Barragán, Joyce; Domínguez-Malfavón, Lilianha; Vargas-Suárez, Martín; González-Hernández, Ricardo; Aguilar-Osorio, Guillermo

    2016-01-01

    ABSTRACT Polyurethane (PU) is widely used in many aspects of modern life because of its versatility and resistance. However, PU waste disposal generates large problems, since it is slowly degraded, there are limited recycling processes, and its destruction may generate toxic compounds. In this work, we isolated fungal strains able to grow in mineral medium with a polyester PU (PS-PU; Impranil DLN) or a polyether PU (PE-PU; Poly Lack) varnish as the only carbon source. Of the eight best Impranil-degrading strains, the six best degraders belonged to the Cladosporium cladosporioides complex, including the species C. pseudocladosporioides, C. tenuissimum, C. asperulatum, and C. montecillanum, and the two others were identified as Aspergillus fumigatus and Penicillium chrysogenum. The best Impranil degrader, C. pseudocladosporioides strain T1.PL.1, degraded up to 87% after 14 days of incubation. Fourier transform infrared (FTIR) spectroscopy analysis of Impranil degradation by this strain showed a loss of carbonyl groups (1,729 cm−1) and N—H bonds (1,540 and 1,261 cm−1), and gas chromatography-mass spectrometry (GC-MS) analysis showed a decrease in ester compounds and increase in alcohols and hexane diisocyanate, indicating the hydrolysis of ester and urethane bonds. Extracellular esterase and low urease, but not protease activities were detected at 7 and 14 days of culture in Impranil. The best eight Impranil-degrading fungi were also able to degrade solid foams of the highly recalcitrant PE-PU type to different extents, with the highest levels generating up to 65% of dry-weight losses not previously reported. Scanning electron microscopy (SEM) analysis of fungus-treated foams showed melted and thinner cell wall structures than the non-fungus-treated ones, demonstrating fungal biodegradative action on PE-PU. IMPORTANCE Polyurethane waste disposal has become a serious problem. In this work, fungal strains able to efficiently degrade different types of

  10. Cometabolism of Methyl tertiary Butyl Ether and Gaseous n-Alkanes by Pseudomonas mendocina KR-1 Grown on C5 to C8 n-Alkanes

    PubMed Central

    Smith, Christy A.; O'Reilly, Kirk T.; Hyman, Michael R.

    2003-01-01

    Pseudomonas mendocina KR-1 grew well on toluene, n-alkanes (C5 to C8), and 1° alcohols (C2 to C8) but not on other aromatics, gaseous n-alkanes (C1 to C4), isoalkanes (C4 to C6), 2° alcohols (C3 to C8), methyl tertiary butyl ether (MTBE), or tertiary butyl alcohol (TBA). Cells grown under carbon-limited conditions on n-alkanes in the presence of MTBE (42 μmol) oxidized up to 94% of the added MTBE to TBA. Less than 3% of the added MTBE was oxidized to TBA when cells were grown on either 1° alcohols, toluene, or dextrose in the presence of MTBE. Concentrated n-pentane-grown cells oxidized MTBE to TBA without a lag phase and without generating tertiary butyl formate (TBF) as an intermediate. Neither TBF nor TBA was consumed by n-pentane-grown cells, while formaldehyde, the expected C1 product of MTBE dealkylation, was rapidly consumed. Similar Ks values for MTBE were observed for cells grown on C5 to C8 n-alkanes (12.95 ± 2.04 mM), suggesting that the same enzyme oxidizes MTBE in cells grown on each n-alkane. All growth-supporting n-alkanes (C5 to C8) inhibited MTBE oxidation by resting n-pentane-grown cells. Propane (Ki = 53 μM) and n-butane (Ki = 16 μM) also inhibited MTBE oxidation, and both gases were also consumed by cells during growth on n-pentane. Cultures grown on C5 to C8 n-alkanes also exhibited up to twofold-higher levels of growth in the presence of propane or n-butane, whereas no growth stimulation was observed with methane, ethane, MTBE, TBA, or formaldehyde. The results are discussed in terms of their impacts on our understanding of MTBE biodegradation and cometabolism. PMID:14660389

  11. Mesler entrainment in alcohols

    NASA Astrophysics Data System (ADS)

    Sundberg-Anderson, R. K.; Saylor, J. R.

    2014-01-01

    Mesler entrainment has been studied extensively in water and, more recently, in silicone oils. Studies of Mesler entrainment in liquids other than these are rare. The extant experimental results in water show significant irreproducibility both in the qualitative characteristics of Mesler entrainment and in the existence or nonexistence of Mesler entrainment when, for example, drops of the same diameter are released from the same height. In contrast, in silicone oils, Mesler entrainment is highly reproducible, essentially occurring either all of the time, or none of the time for a given set of conditions. A goal of the present work was to determine which of these two behaviors is the "standard" behavior—that is, to determine whether Mesler entrainment is typically repeatable or not. The experimental studies presented herein were conducted in three liquids that have not been the subject of detailed investigation to date: ethyl alcohol, isopropyl alcohol, and methyl alcohol. All of these alcohol results showed behavior very similar to that observed in silicone oils, suggesting that Mesler entrainment is typically repeatable and that water is an atypical fluid, causing irreproducible results. Additionally, we present data obtained in silicone oils and combine that with the alcohol data in an attempt to develop a combination of dimensionless groups that predicts the boundaries within which Mesler entrainment occurs for liquids other than water.

  12. Invertebrate models of alcoholism.

    PubMed

    Scholz, Henrike; Mustard, Julie A

    2013-01-01

    For invertebrates to become useful models for understanding the genetic and physiological mechanisms of alcoholism related behaviors and the predisposition towards alcoholism, several general requirements must be fulfilled. The animal should encounter ethanol in its natural habitat, so that the central nervous system of the organism will have evolved mechanisms for responding to ethanol exposure. How the brain adapts to ethanol exposure depends on its access to ethanol, which can be regulated metabolically and/or by physical barriers. Therefore, a model organism should have metabolic enzymes for ethanol degradation similar to those found in humans. The neurons and supporting glial cells of the model organism that regulate behaviors affected by ethanol should share the molecular and physiological pathways found in humans, so that results can be compared. Finally, the use of invertebrate models should offer advantages over traditional model systems and should offer new insights into alcoholism-related behaviors. In this review we will summarize behavioral similarities and identified genes and mechanisms underlying ethanol-induced behaviors in invertebrates. This review mainly focuses on the use of the nematode Caenorhabditis elegans, the honey bee Apis mellifera and the fruit fly Drosophila melanogaster as model systems. We will discuss insights gained from those studies in conjunction with their vertebrate model counterparts and the implications for future research into alcoholism and alcohol-induced behaviors.

  13. Genetics of alcoholism.

    PubMed

    Edenberg, Howard J; Foroud, Tatiana

    2014-01-01

    Multiple lines of evidence strongly indicate that genetic factors contribute to the risk for alcohol use disorders (AUD). There is substantial heterogeneity in AUD, which complicates studies seeking to identify specific genetic factors. To identify these genetic effects, several different alcohol-related phenotypes have been analyzed, including diagnosis and quantitative measures related to AUDs. Study designs have used candidate gene analyses, genetic linkage studies, genomewide association studies (GWAS), and analyses of rare variants. Two genes that encode enzymes of alcohol metabolism have the strongest effect on AUD: aldehyde dehydrogenase 2 and alcohol dehydrogenase 1B each has strongly protective variants that reduce risk, with odds ratios approximately 0.2-0.4. A number of other genes important in AUD have been identified and replicated, including GABRA2 and alcohol dehydrogenases 1B and 4. GWAS have identified additional candidates. Rare variants are likely also to play a role; studies of these are just beginning. A multifaceted approach to gene identification, targeting both rare and common variations and assembling much larger datasets for meta-analyses, is critical for identifying the key genes and pathways important in AUD.

  14. Stress, epigenetics, and alcoholism.

    PubMed

    Moonat, Sachin; Pandey, Subhash C

    2012-01-01

    Acute and chronic stressors have been associated with alterations in mood and increased anxiety that may eventually result in the development of stress-related psychiatric disorders. Stress and associated disorders, including anxiety, are key factors in the development of alcoholism because alcohol consumption can temporarily reduce the drinker's dysphoria. One molecule that may help mediate the relationship between stress and alcohol consumption is brain-derived neurotrophic factor (BDNF), a protein that regulates the structure and function of the sites where two nerve cells interact and exchange nerve signals (i.e., synapses) and which is involved in numerous physiological processes. Aberrant regulation of BDNF signaling and alterations in synapse activity (i.e., synaptic plasticity) have been associated with the pathophysiology of stress-related disorders and alcoholism. Mechanisms that contribute to the regulation of genetic information without modification of the DNA sequence (i.e., epigenetic mechanisms) may play a role in the complex control of BDNF signaling and synaptic plasticity-for example, by modifying the structure of the DNA-protein complexes (i.e., chromatin) that make up the chromosomes and thereby modulating the expression of certain genes. Studies regarding the epigenetic control of BDNF signaling and synaptic plasticity provide a promising direction to understand the mechanisms mediating the interaction between stress and alcoholism.

  15. Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

    PubMed

    da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

    2013-01-01

    Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate.

  16. Effects of carbon nanotubes on atrazine biodegradation by Arthrobacter sp.

    PubMed

    Zhang, Chengdong; Li, Mingzhu; Xu, Xu; Liu, Na

    2015-04-28

    The environmental risks of engineered nanoparticles have attracted attention. However, little is known regarding the effects of carbon nanotubes (CNTs) on the biodegradation and persistence of organic contaminants in water. We investigated the impacts of pristine and oxidized multiwalled CNTs on the atrazine biodegradation rate and efficiency using Arthrobacter sp. At a concentration of 25mg/L, the CNTs enhanced the biodegradation rate by up to 20%; however, at a concentration of 100mg/L, the CNTs decreased the biodegradation rate by up to 50%. The stimulation effects resulted from enhanced bacterial growth and the overexpression of degradation genes. The inhibitory effects resulted from the toxicity of the CNTs at high concentrations. The differences between the two CNTs at tested concentrations were not significant. The biodegradation efficiency was not impacted by adsorption, and the pre-adsorbed atrazine on the CNTs was fully biodegraded when the CNT concentration was ≤25mg/L. This finding was consistent with the lack of observable desorption hysteresis for atrazine on the tested CNTs. Our results indicate that CNTs can enhance or inhibit biodegradation through a balance of two effects: the toxic effects on microbial activity and the effects of the changing bioavailability that result from adsorption and desorption.

  17. Biodegradation of polyalcohol ethoxylate by a wastewater microbial consortium.

    PubMed

    Sharvelle, Sybil E; Garland, Jay; Banks, M K

    2008-04-01

    Polyalcohol ethoxylate (PAE), an anionic surfactant, is the primary component in most laundry and dish wash detergents and is therefore highly loaded in domestic wastewater. Its biodegradation results in the formation of several metabolites and the fate of these metabolites through wastewater treatment plants, graywater recycling processes, and in the environment must be clearly understood. Biodegradation pathways for PAE were investigated in this project with a municipal wastewater microbial consortium. A microtiter-based oxygen sensor system was utilized to determine the preferential use of potential biodegradation products. Results show that while polyethylene glycols (PEGs) were readily degraded by PAE acclimated microorganisms, most of the carboxylic acids tested were not degraded. Biodegradation of PEGs suggests that hydrophobe-hydrophile scission was the dominant pathway for PAE biodegradation in this wastewater community. Ethylene glycol (EG) and diethylene glycol (DEG) were not utilized by microbial populations capable of degrading higher molecular weight EGs. It is possible that EG and DEG may accumulate. The microtiter-based oxygen sensor system was successfully utilized to elucidate information on PAE biodegradation pathways and could be applied to study biodegradation pathways for other important contaminants.

  18. Ionic liquid biodegradability depends on specific wastewater microbial consortia.

    PubMed

    Docherty, Kathryn M; Aiello, Steven W; Buehler, Barbara K; Jones, Stuart E; Szymczyna, Blair R; Walker, Katherine A

    2015-10-01

    Complete biodegradation of a newly-synthesized chemical in a wastewater treatment plant (WWTP) eliminates the potential for novel environmental pollutants. However, differences within- and between-WWTP microbial communities may alter expectations for biodegradation. WWTP communities can also serve as a source of unique consortia that, when enriched, can metabolize chemicals that tend to resist degradation, but are otherwise promising green alternatives. We tested the biodegradability of three ionic liquids (ILs): 1-octyl-3-methylpyridinium bromide (OMP), 1-butyl-3-methylpyridinium bromide (BMP) and 1-butyl-3-methylimidazolium chloride (BMIM). We performed tests using communities from two WWTPs at three time points. Site-specific and temporal variation both influenced community composition, which impacted the success of OMP biodegradability. Neither BMP nor BMIM degraded in any test, suggesting that these ILs are unlikely to be removed by traditional treatment. Following standard biodegradation assays, we enriched for three consortia that were capable of quickly degrading OMP, BMP and BMIM. Our results indicate WWTPs are not functionally redundant with regard to biodegradation of specific ionic liquids. However, consortia can be enriched to degrade chemicals that fail biodegradability assays. This information can be used to prepare pre-treatment procedures and prevent environmental release of novel pollutants.

  19. [Biodegradation Coefficients of Typical Pollutants in the Plain Rivers Network].

    PubMed

    Feng, Shuai; Li, Xu-yongl; Deng, Jian-cai

    2016-05-15

    Biodegradation is a significant part of pollutant integrated degradation, the process rate of which is represented by the biodegradation coefficient. To investigate the biodegradation law of typical pollutants in the plain rivers network located in the upstream of the Lake Taihu, experiments were conducted in site in September 2015, one order kinetics model was used to measure the biodegradation coefficients for permanganate index, ammonia, total nitrogen and total phosphorus, and influencing factors of the biodegradation coefficients were also analyzed. The results showed that the biodegradation coefficients for permanganate index, ammonia, total nitrogen and total phosphorus were 0.008 3-0.126 4 d⁻¹, 0.002 1-0.213 8 d⁻¹, 0.002 1-0.090 5 d⁻¹ and 0.011 0- 0.152 8 d⁻¹, respectively. The influencing factors of the biodegradation coefficients for permanganate index were permanganate index and pH; those for ammonia were ammonia concentration and pH; those for total nitrogen were inorganic nitrogen concentration, total dissolved solid concentration and nitrite concentration; and those for total phosphorus were background concentration and pH. The research results were of important guiding significance for pollutants removal and ecological restoration of the plain rivers network located in the unstream of the Lake Taihu.

  20. Different indices to express biodegradability in organic solid wastes.

    PubMed

    Ponsá, Sergio; Gea, Teresa; Sánchez, Antoni

    2010-01-01

    Respiration indices are suggested in literature as the most suitable stability determination and are proposed as a biodegradability measure in this work. An improved dynamic respiration index methodology is described in this work. This methodology was applied to 58 samples of different types of waste including municipal solid wastes and wastewater sludge, both raw materials and samples collected in a mechanical-biological treatment plant at different stages of biodegradation. The information obtained allowed to establish a qualitative classification of wastes in three categories: highly biodegradable, moderately biodegradable, and wastes of low biodegradability. Results were analyzed in terms of long and short-term indices and index expression: dynamic respiration indices expressed as average oxygen uptake rate (mg O(2) g(-1) dry matter [DM] h(-1)) at 1 and 24 h of maximum activity (DRI(1h), DRI(24h)); and cumulative oxygen consumption in 24 h of maximum activity and 4 d (AT(24h), AT(4)). The statistical comparison of indices and wastes is also presented. Raw sludge presented the highest biodegradability followed by the organic fraction of municipal solid waste and anaerobically digested sludge. All indices correlated well but different correlations were found for the different wastes analyzed. The information in the dynamic respiration profile allows for the calculation of different indices that provide complementary information. The combined analysis of DRI(24h) and AT(4) is presented here as the best tool for biodegradable organic matter content characterization and process requirements estimation.

  1. Research approach to teaching groundwater biodegradation in karst aquifers

    USGS Publications Warehouse

    King, L.; Byl, T.; Painter, R.

    2006-01-01

    TSU in partnership with the USGS has conducted extensive research regarding biode??gradation of contaminants in karst aquifers. This research resulted in the development of a numerical approach to modeling biodegradation of contaminants in karst aquifers that is taught to environmental engineering students in several steps. First, environmental engineering students are taught chemical-reaction engineering principles relating to a wide variety of environmental fate and transport issues. Second, as part of TSU's engineering course curriculum, students use a non-ideal flow laboratory reactor system and run a tracer study to establish residence time distribution (RTD). Next, the students couple that formula to a first-order biodegradation rate and predict the removal of a biodegradable contaminant as a function of residence time. Following this, students are shown data collected from karst bedrock wells that suggest that karst aquifers are analogous to non-ideal flow reactors. The students are challenged to develop rates of biodegradation through lab studies and use their results to predict biodegradaton at an actual contaminated karst site. Field studies are also conducted to determine the accuracy of the students' predictions. This academic approach teaches biodegradation processes, rate-kinetic processes, hydraulic processes and numerical principles. The students are able to experience how chemical engineering principles can be applied to other situations, such as, modeling biodegradation of contaminants in karst aquifers. This paper provides background on the chemical engineering principles and karst issues used in the research-enhanced curriculum. ?? American Society for Engineering Education, 2006.

  2. Degradation of Oxo-Biodegradable Plastic by Pleurotus ostreatus

    PubMed Central

    da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

    2013-01-01

    Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate. PMID:23967057

  3. 78 FR 65347 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-10-31

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Special Emphasis... Abuse and Alcoholism, 5635 Fishers Lane (Teleconference), Rockville, MD 20855. Contact Person:...

  4. 78 FR 21615 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-04-11

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Initial ] Review... Foster, Ph.D., Scientific Review Administrator, National Institutes on Alcohol Abuse &...

  5. 78 FR 38353 - National Institute on Alcohol Abuse and Alcoholism; Notice of Closed Meeting

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-06-26

    ... HUMAN SERVICES National Institutes of Health National Institute on Alcohol Abuse and Alcoholism; Notice... personal privacy. Name of Committee: National Institute on Alcohol Abuse and Alcoholism Special Emphasis Panel; Review of Applications on HIV- AIDS/Alcohol Comparative Effectiveness & Implementation...

  6. Environmental and human safety of major surfactants. Volume 1. Anionic surfactants. Part 2. Alcohol ethoxy sulfates. Final report

    SciTech Connect

    Not Available

    1991-02-01

    The report discusses critical reviews of published literature and unpublished company data on major surfactants. Part 2 of Vol. 1 discusses the chemistry, biodegradation, environmental effects and safety and human safety of alcohol ethoxy sulfates. The information presented updates and supplements similar data included in two predecessor studies, Human Safety and Environmental Aspects of Major Surfactants (1977) NTIS Accession Number PB301193 and Human and Environmental Aspects of Major Surfactants (Supplement) (1981) NTIS Accessiion Number PB81-182453.

  7. Alcoholic liver disease and pancreatitis: global health problems being addressed by the US National Institute on Alcohol Abuse and Alcoholism.

    PubMed

    Warren, Kenneth R; Murray, Margaret M

    2013-08-01

    The review article summarizes the mission of the National Institute on Alcohol Abuse and Alcoholism (NIAAA) with focus on the NIAAA's current and future research version for alcoholic liver disease and alcoholic pancreatitis.

  8. Competitive substrate biodegradation during surfactant-enhanced remediation

    SciTech Connect

    Goudar, C.; Strevett, K.; Grego, J.

    1999-12-01

    The impact of synthetic surfactants on the aqueous phase biodegradation of benzene, toluene, and p-xylene (BTpX) was studied using two anionic surfactants, sodium dodecyl sulfate (SDS) and sodium dodecyl benzene sulfonate (SDBS), and two nonionic surfactants, POE(20) sorbitan monooleate (T-maz-80) and octyl-phenolpoly(ethyleneoxy) ethanol (CA-620). Batch biodegradation experiments were performed to evaluate surfactant biodegradability using two different microbial cultures. Of the four surfactants used in this study, SDS and T-maz-80 were readily degraded by a microbial consortium obtained from an activated sludge treatment system, whereas only SDS was degraded by a microbial culture that was acclimated to BTpX. Biodegradation kinetic parameters associated with SDS and T-maz-80 degradation by the activated sludge consortium were estimated using respirometric data in conjunction with a nonlinear parameter estimation technique as {mu}{sub max} = 0.93 h{sup {minus}1}, K{sub s}= 96.18 mg/L and {mu}{sub max} = 0.41 h{sup {minus}1}, K{sub s} = 31.92 mg/L, respectively. When both BTpX and surfactant were present in the reactor along with BTpX-acclimated microorganisms, two distinct biodegradation patterns were seen. SDS was preferentially utilized inhibiting hydrocarbon biodegradation, whereas, the other three surfactants had no impact on BTpX biodegradation. None of the four surfactants were toxic to the microbial cultures used in this study. Readily biodegradable surfactants are not very effective for subsurface remediation applications as they are rapidly consumed, and also because of their potential inhibitory effects on intrinsic hydrocarbon biodegradation. This greatly increases treatment costs as surfactant recovery and reuse are adversely affected.

  9. Fully biodegradable coronary stents : progress to date.

    PubMed

    Ramcharitar, Steve; Serruys, Patrick W

    2008-01-01

    The limitations of currently available metallic drug-eluting stents have renewed interest in biodegradable stents (BDS). Apart from removing the (offending) foreign material that may potentiate a thrombotic event, BDS have the advantage of avoiding 'full metal jackets,' and thus can preclude subsequent coronary surgery. In addition, they do not interfere with the diagnostic evaluation of non-invasive imaging such as cardiac magnetic resonance and CT. There are now several BDS in development or in clinical trials that incorporate a variety of biodegradable polymer technologies. Two broad categories of materials are generally used: those made from organic biopolymers and those made from corrodible metals. However, to date, none of the materials/stents tested have been able to establish a perfect balance between biocompatibility, the kinetics of degradation needed to maintain mechanical strength to limit recoil, and inflammation. However, studies, such as the ABSORB trial with the everolimus eluting poly-L-lactide stent, which demonstrated comparable restenotic rates with bare metallic stents and a low incidence of major adverse cardiac events (MACE) at 12 months of 3.3%, with only one patient having a non-Q-wave myocardial infarction and no target lesion revascularization, suggest that there has been significant progress with respect to the earlier prototypes. The acute recoil observed could potentially be addressed with the polytyrosine REVA stent currently being evaluated in the RESORB trial, which incorporates a novel locking mechanism within its design. Alternative BDS designs include the combination of an antiproliferative drug with endothelial progenitor cell capturing antibodies to facilitate epithelialization and/or dual eluting having, in addition to the antiproliferative drug, polymeric salicyclic acid to limit inflammation. Compared with biodegradable polymers, there are fewer metals used in the manufacture of BDS. The only metal BDS in trials is the

  10. Evaluation of the biodegradation of Alaska North Slope oil in microcosms using the biodegradation model BIOB.

    PubMed

    Torlapati, Jagadish; Boufadel, Michel C

    2014-01-01

    We present the details of a numerical model, BIOB that is capable of simulating the biodegradation of oil entrapped in the sediment. The model uses Monod kinetics to simulate the growth of bacteria in the presence of nutrients and the subsequent consumption of hydrocarbons. The model was used to simulate experimental results of Exxon Valdez oil biodegradation in laboratory columns (Venosa et al., 2010). In that study, samples were collected from three different islands: Eleanor Island (EL107), Knight Island (KN114A), and Smith Island (SM006B), and placed in laboratory microcosms for a duration of 168 days to investigate oil bioremediation through natural attenuation and nutrient amendment. The kinetic parameters of the BIOB model were estimated by fitting to the experimental data using a parameter estimation tool based on Genetic Algorithms (GA). The parameter values of EL107 and KN114A were similar whereas those of SM006B were different from the two other sites; in particular biomass growth at SM006B was four times slower than at the other two islands. Grain size analysis from each site revealed that the specific surface area per unit mass of sediment was considerably lower at SM006B, which suggest that the surface area of sediments is a key control parameter for microbial growth in sediments. Comparison of the BIOB results with exponential decay curves fitted to the data indicated that BIOB provided better fit for KN114A and SM006B in nutrient amended treatments, and for EL107 and KN114A in natural attenuation. In particular, BIOB was able to capture the initial slow biodegradation due to the lag phase in microbial growth. Sensitivity analyses revealed that oil biodegradation at all three locations were sensitive to nutrient concentration whereas SM006B was sensitive to initial biomass concentration due to its slow growth rate. Analyses were also performed to compare the half-lives of individual compounds with that of the overall polycyclic aromatic hydrocarbons

  11. Advances in Alcoholism Treatment

    PubMed Central

    Huebner, Robert B.; Kantor, Lori Wolfgang

    2011-01-01

    Researchers are working on numerous and varied approaches to improving the accessibility, quality, effectiveness, and cost-effectiveness of treatment for alcohol use disorders (AUDs). This overview article summarizes the approaches reviewed in this issue, including potential future developments for alcoholism treatment, such as medications development, behavioral therapy, advances in technology that are being used to improve treatment, integrated care of patients with AUDs and co-occurring disorders, the role of 12-step programs in the broader realm of treatment, treating patients with recurring and chronic alcohol dependence, strategies to close the gap between treatment need and treatment utilization, and how changes in the health care system may affect the delivery of treatment. This research will not only reveal new medications and behavioral therapies but also will contribute to new ways of approaching current treatment problems. PMID:23580014

  12. Alcohol fuels for aviation

    SciTech Connect

    Schauffler, P.

    1982-06-01

    The ten-fold increase in aviation fuel prices in eight years has caused a reassessment of alcohol fuels. In a recent test, methanol fuel-flow rate was high at takeoff, and levelled off at 10,000 feet, but above 18,000 fell 30% below avgas use. Because methanol sells thirty cents below avgas per gallon it is already an attractive fuel for piston-engine aircraft. But as 95% of aviation fuel is burned as kerosene in turbines a test program has been set up to look at the performance of small shaft turbine engines with various combinations of alcohols and water, and of straight methanol, and to look at major thrust engine at optimum fuel as well. These tests should determine the overall alcohol potentials for aviation. The tests will also tell if the breakthrough will be modest or major.

  13. [Alcohol and the cardiovascular system].

    PubMed

    Frenzel, H; Roth, H; Schwartzkopff, B

    1988-10-01

    Because of the high frequency of cardiovascular diseases and a steadily increasing consumption of alcohol the potentially causal relationship between alcohol and cardiovascular diseases gains great interest for public health policy. Alcohol and its metabolites induce a toxic damage of myocardial metabolism with an injury of electromechanic coupling. As a consequence of acute alcoholic intake cardiac arrhythmias and a reduced contractility of the myocardium are found not only for chronic alcoholics but also in healthy non-drinkers. Chronic abuse of alcoholic beverages for many years can be the cause of alcoholic cardiomyopathy in a small percentage of patients, who have a bad prognosis. Atria and ventricles are dilated, light and electron microscopic changes of the myocardium are unspecific. The pathogenesis of alcoholic cardiomyopathy is unknown, modulations of cardiomyocytic membranes are discussed in the course of a toxic damage. In the genesis of atherosclerosis alcohol can approach from different sites: Changings on thrombocytes and an increase of HDL-cholesterin can be protective, however an increase in blood pressure support the process of atherosclerosis. In numerous investigations a smaller degree of atherosclerosis was found for little or moderate alcohol intake, while in chronic heavy abuse of alcohol a higher extent of atherosclerosis was observed. As the amount of alcohol, assumed to be protective against the development of atherosclerosis, is consumed already by the majority of the population, there is no reason to propagate a regulate consume of moderate amount of alcoholic beverages.

  14. Receptivity to alcohol marketing predicts initiation of alcohol use

    PubMed Central

    Henriksen, Lisa; Feighery, Ellen C.; Schleicher, Nina C.; Fortmann, Stephen P.

    2008-01-01

    Purpose This longitudinal study examined the influence of alcohol advertising and promotions on the initiation of alcohol use. A measure of receptivity to alcohol marketing was developed from research about tobacco marketing. Recall and recognition of alcohol brand names were also examined. Methods Data were obtained from in-class surveys of 6th, 7th, and 8th graders at baseline and 12-month follow-up. Participants who were classified as never drinkers at baseline (n=1,080) comprised the analysis sample. Logistic regression models examined the association of advertising receptivity at baseline with any alcohol use and current drinking at follow-up, adjusting for multiple risk factors, including peer alcohol use, school performance, risk taking, and demographics. Results At baseline, 29% of never drinkers either owned or wanted to use an alcohol branded promotional item (high receptivity), 12% students named the brand of their favorite alcohol ad (moderate receptivity) and 59% were not receptive to alcohol marketing. Approximately 29% of adolescents reported any alcohol use at follow-up; 13% reported drinking at least 1 or 2 days in the past month. Never drinkers who reported high receptivity to alcohol marketing at baseline were 77% more likely to initiate drinking by follow-up than those were not receptive. Smaller increases in the odds of alcohol use at follow-up were associated with better recall and recognition of alcohol brand names at baseline. Conclusions Alcohol advertising and promotions are associated with the uptake of drinking. Prevention programs may reduce adolescents’ receptivity to alcohol marketing by limiting their exposure to alcohol ads and promotions and by increasing their skepticism about the sponsors’ marketing tactics. PMID:18155027

  15. [Does acamprosate diminish the appetite for alcohol in weaned alcoholics?].

    PubMed

    Roussaux, J P; Hers, D; Ferauge, M

    1996-01-01

    A population of 127 alcoholics of both sexes, hospitalized and weaned (DSM III diagnose: Alcohol Abuse and Alcohol Dependence) received Acamprosate (n = 63) or placebo (n = 64) in a double blind randomized therapeutic trail. The patients were followed during three months and anamnestic as well as biological data were recorded. It appeared no significant differences between the two groups of patients. This negative result could perhaps be explained by the heaviness of the pathology of this hospitalized alcoholic population.

  16. Neuropathology of alcoholism.

    PubMed

    Harper, C G; Kril, J J

    1990-01-01

    There are wide ranging effects of alcohol on the nervous system. Some interfere with physiological and neurochemical functions but ultimately structural damage occurs. During life one of the most impressive changes is brain shrinkage which can be visualized using neuroradiological imaging techniques. This article reviews the pathological explanations for brain shrinkage and addresses the question of the pathogenesis of the reversible component of this damage in relation to prolonged abstinence from alcohol. This shrinkage seems to relate to a loss of white matter. However, the cortex is also abnormal in that there is a loss of neurones from the frontal region. In this and other regions of the cortex examined there is shrinkage of the neuronal soma. This is reflected in a retraction of the neuronal dendritic arbor which plays a crucial role in cell-to-cell communication. In addition, the cerebellum appears to be vulnerable in alcoholic patients although it may well be that associated nutritional deficiencies play an important role. The Wernicke-Korsakoff syndrome is another important deficiency disorder which is seen most frequently in alcoholic patients. Two important population groups which are considered in this review are females and moderate ('social') drinkers. Females are thought to be more susceptible to the damaging effects of alcohol than males and this is examined in the light of the scant data available. Similarly, there are few neuropathological data on people who drink 30-80 grams of alcohol per day. In order to assess so-called 'safe levels of drinking' this is an important group to study.

  17. Biodegradability enhancement of textile wastewater by electron beam irradiation

    NASA Astrophysics Data System (ADS)

    Kim, Tak-Hyun; Lee, Jae-Kwang; Lee, Myun-Joo

    2007-06-01

    Textile wastewater generally contains various pollutants, which can cause problems during biological treatment. Electron beam radiation technology was applied to enhance the biodegradability of textile wastewater for an activated sludge process. The biodegradability (BOD 5/COD) increased at a 1.0 kGy dose. The biorefractory organic compounds were converted into more easily biodegradable compounds such as organic acids having lower molecular weights. In spite of the short hydraulic retention time (HRT) of the activated sludge process, not only high organic removal efficiencies, but also high microbial activities were achieved. In conclusion, textile wastewater was effectively treated by the combined process of electron beam radiation and an activated sludge process.

  18. Biodegradable and biocompatible polymers for tissue engineering application: a review.

    PubMed

    Asghari, Fatemeh; Samiei, Mohammad; Adibkia, Khosro; Akbarzadeh, Abolfazl; Davaran, Soodabeh

    2017-03-01

    Since so many years ago, tissue damages that are caused owing to various reasons attract scientists' attention to find a practical way to treat. In this regard, many studies were conducted. Nano scientists also suggested some ways and the newest one is called tissue engineering. They use biodegradable polymers in order to replace damaged structures in tissues to make it practical. Biodegradable polymers are dominant scaffolding materials in tissue engineering field. In this review, we explained about biodegradable polymers and their application as scaffolds.

  19. Evaluation and Optimization of MTBE Biodegradation in Aquifers, Final Report

    SciTech Connect

    Legler, T; Balser, L; Koester, C; Wilson, W

    2004-02-13

    This study was focused on meeting the following objectives concerning the process of methyl tertiary butyl ether (MTBE) biodegradation, with the goal of optimizing this process in situ: 1. Assess whether intrinsic bioattenuation of MTBE is feasible under aerobic conditions across several contaminated sites. 2. Determine the effect of co-contaminants, specifically water-soluble gasoline components (most notably benzene, toluene, ethylbenzene and xylenes [BTEX]) on MTBE biodegradation. 3. Determine whether microbial and/or chemical factors contribute to different MTBE degradative activities. 4. Isolate and characterize MTBE-degrading microorganisms from sediments in which MTBE biodegradation was observed.

  20. Alcohol fuel from sugarbeets

    SciTech Connect

    Doney, D.L.; Theurer, J.C.

    1980-05-01

    Sugarbeets are a prime candidate for alcohol fuel production because they store their energy and much of their biomass as sucrose, a fermentable sugar. At the present time, it is uneconomical to produce alcohol from sugarbeets and the balance is marginal. A number of approaches could improve both the economic and the energy situation: 1) increasing production per acre; 2) reducing conversion costs; 3) integrating sugarbeet - sweet sorghum crops; and 4) utilizing low priority sources such as geothermal, coal, bagasse and solar for the energy of conversion.

  1. Fermentative alcohol production

    DOEpatents

    Wilke, Charles R.; Maiorella, Brian L.; Blanch, Harvey W.; Cysewski, Gerald R.

    1982-01-01

    An improved fermentation process for producing alcohol which includes the combination of vacuum fermentation and vacuum distillation. Preferably, the vacuum distillation is carried out in two phases, one a fermentor proper operated at atmospheric pressure and a flash phase operated at reduced pressure with recycle of fermentation brew having a reduced alcohol content to the fermentor, using vapor recompression heating of the flash-pot recycle stream to heat the flash-pot or the distillation step, and using "water load balancing" (i.e., the molar ratio of water in the fermentor feed is the same as the molar ratio of water in the distillation overhead).

  2. Fermentative alcohol production

    SciTech Connect

    Blanch, H.W.; Cysewski, G.R.; Maiorella, B.L.; Wilke, C.R.

    1982-11-16

    An improved fermentation process is disclosed for producing alcohol which includes the combination of vacuum fermentation and vacuum distillation. Preferably, the vacuum distillation is carried out in two phases. One is a fermentor proper operated at atmospheric pressure and the other is a flash phase operated at reduced pressure with recycle of fermentation brew having a reduced alcohol content to the fermentor, using vapor recompression heating of the flash-pot recycle stream to heat the flash-pot or the distillation step, and using ''water load balancing'' (i.e., the molar ratio of water in the fermentor feed is the same as the molar ratio of water in the distillation overhead).

  3. Improved fermentative alcohol production

    SciTech Connect

    Wilke, C.R.; Maiorella, B.L.; Blanch, M.W.; Cysewski, G.R.

    1980-11-26

    An improved fermentation process is described for producing alcohol which includes the combination of vacuum fermentation and vacuum distillation. Preferably, the vacuum distillation is carried out in two phases, one a fermentor proper operated at atmospheric pressure and a flash phase operated at reduced pressure with recycle of fermentation brew having a reduced alcohol content to the fermentor, using vapor recompression heating of the flash-pot recycle stream to heat the flash-pot or the distillation step, and using water load balancing (i.e., the molar ratio of water in the fermentor feed is the same as the molar ratio of water in the distillation overhead).

  4. Experimental alcohol blastopathy.

    PubMed

    Sandor, S

    1988-01-01

    Experimental data are presented with respect to "experimental alcohol blastopathy" performed in our laboratory. As in our interpretation the notion of blastopathy involves both pathological changes during preimplantation development due to previous, preconceptional or preimplantation influences and later, pre- or postnatal effects induced by factors active during the preimplantation period, up to now the following experimental models were applied (on rats and mice): chronic and acute maternal, biparental or paternal ethanol alcoholization; preimplantation treatment with acetaldehyde or disulfiram followed by ethanol administration; acute ethanol intoxication before implantation on the background of chronic maternal ethanol intake; chronic maternal intake of various beverages. The main components of experimental alcohol blastopathy detected (by using a complex control methodology) were: pathological changes during the preimplantation developmental stages (lower mean number of embryos/animal, retardation of development, lowered migration rate of the embryos from the oviduct to the uterus, higher number of pathological morphological features), delayed implantation, disturbances of the early postimplantation development, retarded late foetal and placental growth. The effect of ethanol may be direct (ethanol being detectable in the oviductal and uterine fluid after both acute and chronic alcoholization) or indirect, via changes of the maternal macro- or microenvironment. The increase of the maternal blood acetaldehyde level may contribute to the appearance of alcohol blastopathy. Chronic beer and wine intake and acute intoxication with cognac suggest - up to now - the enhancing effect of beverage congeners. The noxious effect of acute ethanol intoxication superposed to chronic alcoholization is more marked that the separate effect of the two kinds of treatment. The chronic ethanol intake of fertilizing males (in mice) leads, both in the case of treated or untreated

  5. Alcohol Promotional Clothing Items and Alcohol Use by Underage Consumers.

    ERIC Educational Resources Information Center

    Workman, Jane E.

    2003-01-01

    Of 154 female and 106 male adolescents, 76.3% had tried alcohol; more than 36% owned alcohol promotional clothing and more than half had seen such clothing at school. Ownership increased with alcohol use status. Those who received such clothing from their parents were more likely to perceive parental approval of their drinking. (Contains 59…

  6. Fetal Alcohol Syndrome and Fetal Alcohol Effects: Principles for Educators.

    ERIC Educational Resources Information Center

    Burgess,Donna M.; Streissguth, Ann P.

    1992-01-01

    Fetal alcohol syndrome (FAS), the leading cause of mental retardation, often goes unrecognized because of social and emotional taboos about alcohol and alcoholism. This article describes medical and behavioral characteristics of FAS children and describes guiding principles for educators, based on early intervention, teaching communication and…

  7. Fetal Alcohol Syndrome and Fetal Alcohol Effects in Child Development.

    ERIC Educational Resources Information Center

    Pancratz, Diane R.

    This literature review defines Fetal Alcohol Syndrome (FAS) and Fetal Alcohol Effects (FAE) and considers their causes, diagnoses, prevalence, and educational ramifications. Effects of alcohol during each of the trimesters of pregnancy are summarized. Specific diagnostic characteristics of FAS are listed: (1) growth deficiency, (2) a…

  8. Alcoholism: Devastation for Indians. 36 Lessons on Alcoholism.

    ERIC Educational Resources Information Center

    Pike, William A.

    In an attempt to educate American Indians about the problems of alcohol abuse, the 36-lesson book presents historical, cultural, legal, medical, social, and personal facts about alcohol and alcohol abuse. Each 3- or 4-page lesson is illustrated in black and white and consists of an introductory narrative, learning activities, and follow-up…

  9. The degradability of biodegradable plastics in aerobic and anaerobic waste landfill model reactors.

    PubMed

    Ishigaki, Tomonori; Sugano, Wataru; Nakanishi, Akane; Tateda, Masafumi; Ike, Michihiko; Fujita, Masanori

    2004-01-01

    Degradabilities of four kinds of commercial biodegradable plastics (BPs), polyhydroxybutyrate and hydroxyvalerate (PHBV) plastic, polycaprolactone plastic (PCL), blend of starch and polyvinyl alcohol (SPVA) plastic and cellulose acetate (CA) plastic were investigated in waste landfill model reactors that were operated as anaerobically and aerobically. The application of forced aeration to the landfill reactor for supplying aerobic condition could potentially stimulate polymer-degrading microorganisms. However, the individual degradation behavior of BPs under the aerobic condition was completely different. PCL, a chemically synthesized BP, showed film breakage under the both conditions, which may have contributed to a reduction in the waste volume regardless of aerobic or anaerobic conditions. Effective degradation of PHBV plastic was observed in the aerobic condition, though insufficient degradation was observed in the anaerobic condition. But the aeration did not contribute much to accelerate the volume reduction of SPVA plastic and CA plastic. It could be said that the recalcitrant portions of the plastics such as polyvinyl alcohol in SPVA plastic and the highly substituted CA in CA plastic prevented the BP from degradation. These results indicated existence of the great variations in the degradability of BPs in aerobic and anaerobic waste landfills, and suggest that suitable technologies for managing the waste landfill must be combined with utilization of BPs in order to enhance the reduction of waste volume in landfill sites.

  10. Purification and characterization of a biodegradable plastic-degrading enzyme from Aspergillus oryzae.

    PubMed

    Maeda, Hiroshi; Yamagata, Youhei; Abe, Keietsu; Hasegawa, Fumihiko; Machida, Masayuki; Ishioka, Ryoji; Gomi, Katsuya; Nakajima, Tasuku

    2005-06-01

    We used biodegradable plastics as fermentation substrates for the filamentous fungus Aspergillus oryzae. This fungus could grow under culture conditions that contained emulsified poly-(butylene succinate) (PBS) and emulsified poly-(butylene succinate-co-adipate) (PBSA) as the sole carbon source, and could digest PBS and PBSA, as indicated by clearing of the culture supernatant. We purified the PBS-degrading enzyme from the culture supernatant, and its molecular mass was determined as 21.6 kDa. The enzyme was identified as cutinase based on internal amino acid sequences. Specific activities against PBS, PBSA and poly-(lactic acid) (PLA) were determined as 0.42 U/mg, 11 U/mg and 0.067 U/mg, respectively. To obtain a better understanding of how the enzyme recognizes and hydrolyzes PBS/PBSA, we investigated the environment of the catalytic pocket, which is divided into carboxylic acid and alcohol recognition sites. The affinities for different substrates depended on the carbon chain length of the carboxylic acid in the substrate. Competitive inhibition modes were exhibited by carboxylic acids and alcohols that consisted of C4-C6 and C3-C8 chain lengths, respectively. Determination of the affinities for different chemicals indicated that the most preferred substrate for the enzyme would consist of butyric acid and n-hexanol.

  11. Biodegradable thermogelling polymers: working towards clinical applications.

    PubMed

    Dou, Qing Qing; Liow, Sing Shy; Ye, Enyi; Lakshminarayanan, Rajamani; Loh, Xian Jun

    2014-07-01

    As society ages, aging medical problems such as organ damage or failure among senior citizens increases, raising the demand for organ repair technologies. Synthetic materials have been developed and applied in various parts of human body to meet the biomedical needs. Hydrogels, in particular, have found extensive applications as wound healing, drug delivery and controlled release, and scaffold materials in the human body. The development of the next generation of soft hydrogel biomaterials focuses on facile synthetic methods, efficacy of treatment, and tunable multi-functionalities for applications. Supramolecular 3D entities are highly attractive materials for biomedical application. They are assembled by modules via various non-covalent bonds (hydrogen bonds, p-p stacking and/or van der Waals interactions). Biodegradable thermogels are a class of such supramolecular assembled materials. Their use as soft biomaterials and their related applications are described in this Review.

  12. Biodegradable nanoparticles for sustained occular drug delivery

    NASA Astrophysics Data System (ADS)

    Cleroux, Carolyne

    Apoptosis (programmed cell-death) is a common final pathway through which cells die in retinal degenerative diseases. The purpose of this project was to develop biodegradable nanoparticles that quickly deliver XIAP, an inhibitor of apoptosis, to retinal cells following acute insults. In vitro protein release profiles from different formulations were established, and two cell types were incubated with nanoparticles to assess cellular uptake. Subretinal injections were carried out in rats to assess in vivo localization and possible toxicity. In vitro studies showed an initial burst of protein followed by sustained release, with overall low levels of protein release. Cell culture experiments suggest that particles are mostly membrane-bound, and some may be internalized. In vivo experiments revealed no signs of toxicity, and protein localized within the photoreceptor layer. In conclusion, nanoparticles may provide a good delivery system for XIAP; however higher levels of protein release are needed for neuroprotection, warranting further investigation.

  13. Biodegradation and flushing of MBT wastes.

    PubMed

    Siddiqui, A A; Richards, D J; Powrie, W

    2013-11-01

    Mechanical-biological treatment (MBT) processes are increasingly being adopted as a means of diverting biodegradable municipal waste (BMW) from landfill, for example to comply with the EU Landfill Directive. However, there is considerable uncertainty concerning the residual pollution potential of such wastes. This paper presents the results of laboratory experiments on two different MBT waste residues, carried out to investigate the remaining potential for the generation of greenhouse gases and the flushing of contaminants from these materials when landfilled. The potential for gas generation was found to be between 8% and 20% of that for raw MSW. Pretreatment of the waste reduced the potential for the release of organic carbon, ammoniacal nitrogen, and heavy metal contents into the leachate; and reduced the residual carbon remaining in the waste after final degradation from ∼320g/kg dry matter for raw MSW to between 183 and 195g/kg dry matter for the MBT wastes.

  14. Amine-reactive biodegradable diblock copolymers.

    PubMed

    Tessmar, Jörg K; Mikos, Antonios G; Göpferich, Achim

    2002-01-01

    A new class of diblock copolymers was synthesized from biodegradable poly(lactic acid) and poly(ethylene glycol)minus signmonoamine. These polymers were activated by covalently attaching linkers such as disuccinimidyl tartrate or disuccinimidyl succinate to the hydrophilic polymer chain. The polymers were characterized by (1)H NMR spectroscopy, (13)C NMR spectroscopy and gel permeation chromatography (GPC). These investigations indicated that the polymers were obtained with the correct composition, in high purities, and the expected molecular weight. By using dyes containing primary amine groups such as 5-aminoeosin as model substrates, it was possible to show that the polymers are able to bind such compounds covalently. The diblock copolymers were developed to suppress unspecific protein adsorption and allow the binding of bioactive molecules by instant surface modification. The polymers are intended to be used for tissue engineering applications where surface immobilized cell adhesion peptides or growth factors are needed to control cell behavior.

  15. Biodegradable polymeric fiber structures in tissue engineering.

    PubMed

    Tuzlakoglu, Kadriye; Reis, Rui L

    2009-03-01

    Tissue engineering offers a promising new approach to create biological alternatives to repair or restore function of damaged or diseased tissues. To obtain three-dimensional tissue constructs, stem or progenitor cells must be combined with a highly porous three-dimensional scaffold, but many of the structures purposed for tissue engineering cannot meet all the criteria required by an adequate scaffold because of lack of mechanical strength and interconnectivity, as well as poor surface characteristics. Fiber-based structures represent a wide range of morphological and geometric possibilities that can be tailored for each specific tissue-engineering application. The present article overviews the research data on tissue-engineering therapies based on the use of biodegradable fiber architectures as a scaffold.

  16. Biodegradable synthetic scaffolds for tendon regeneration

    PubMed Central

    Reverchon, Ernesto; Baldino, Lucia; Cardea, Stefano; De Marco, Iolanda

    2012-01-01

    Summary Tissue regeneration is aimed at producing biological or synthetic scaffolds to be implanted in the body for regenerate functional tissues. Several techniques and materials have been used to obtain biodegradable synthetic scaffolds, on which adhesion, growth, migration and differentiation of human cells has been attempted. Scaffolds for tendon regeneration have been less frequently proposed, because they have a complex hierarchical structure and it is very difficult to mimic their peculiar mechanical properties. In this review, we critically analyzed the proposed materials and fabrication techniques for tendon tissue engineering and we indicated new preparation processes, based on the use of supercritical fluids, to produce scaffolds with characteristics very similar to the native tendon structure. PMID:23738295

  17. Partial Discharge Degradation of Several Biodegradable Polymers

    NASA Astrophysics Data System (ADS)

    Fuse, Norikazu; Fujita, Shinjiro; Hirai, Naoshi; Tanaka, Toshikatsu; Kozako, Masahiro; Kohtoh, Masanori; Okabe, Shigemitsu; Ohki, Yoshimichi

    Partial discharge (PD) resistance was examined by applying a constant voltage for four kinds of biodegradable polymers, i.e. poly-L-lactic acid (PLLA), polyethylene terephthalate succinate (PETS), poly ε-caprolactone butylene succinate (PCL-BS), and polybutylene succinate (PBS), and the results were compared with those of low density polyethylene (LDPE) and crosslinked low density polyethylene (XLPE). The PD resistance is determined by the erosion depth and the surface roughness caused by PDs, and is ranked as LDPE ≅ XLPE > PLLA ≅ PETS > PBS > PCL-BS. This means that the sample with a lower permittivity has better PD resistance. Furthermore, observations of the sample surface by a polarization microscope and a laser confocal one reveal that crystalline regions with spherulites are more resistant to PDs than amorphous regions. Therefore, good PD resistance can be achieved by the sample with a high crystallinity and a low permittivity.

  18. Biodegradable polymer adhesives, hybrids and nanomaterials

    NASA Astrophysics Data System (ADS)

    Mylonakis, Andreas

    Biodegradable polymeric products and organic-inorganic hybrid materials for a diversity of applications are the two main fields on which this research has been focused. A novel biodegradable adhesive, which mimics marine adhesive proteins, has been synthesized by the covalent incorporation of 3,4-dihydroxybenzoic acid onto the chitosan backbone. The adhesive strength of these materials varies with the molecular weight of the polysaccharide, the amount of diphenolics present and the curing time. Infrared spectroscopy (IR), nuclear magnetic resonance spectroscopy (NMR) and ultraviolet-visible spectroscopy (UV) have been used to qualitatively and quantitatively establish the amount of the diphenolic moiety present on the backbone of the biodegradable polymers. The as synthesized polymers combine both the adhesive capability of the diphenolic function and the healing effect of chitosan. The biocompatibility and biodegradability of these modified chitosans offer the promise of utility of these novel materials in dental and medical applications. Organic-inorganic hybrid materials with low volume shrinkage and excellent mechanical properties were synthesized by the covalent incorporation of 2-hydroxyethyl methacrylate and glycidyl methacrylate on pre-hydrolyzed sol-gel silica. These hybrid materials exhibited low volume shrinkage during polymerization and were crack-free during storage for about twelve months. The mechanical properties of these materials are composition dependent. Incorporation of silica effectively increased the compressive yield stress and modulus of the obtained poly(HEMAGMA-silica) hybrid materials. A series of new electroactive hybrid materials have been synthesized by covalent incorporation of polyaniline into polyacrylate-silica hybrids. The formulation involves the radical co-polymerization of glycidyl methacrylate-polyaniline (GMA-PANi) and glycidyl methacrylate2-hydroxyethyl methacrylate-silica (GMA-HEMA-silica) to yield poly

  19. 40 CFR 721.10485 - Reaction products of alcohols, alkyl alcohols, amino alcohols and methanol sodium salts (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Reaction products of alcohols, alkyl alcohols, amino alcohols and methanol sodium salts (generic). 721.10485 Section 721.10485 Protection of... alcohols, alkyl alcohols, amino alcohols and methanol sodium salts (generic). (a) Chemical substance...

  20. 40 CFR 721.10485 - Reaction products of alcohols, alkyl alcohols, amino alcohols and methanol sodium salts (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Reaction products of alcohols, alkyl alcohols, amino alcohols and methanol sodium salts (generic). 721.10485 Section 721.10485 Protection of... alcohols, alkyl alcohols, amino alcohols and methanol sodium salts (generic). (a) Chemical substance...