WorldWideScience

Sample records for alcohol tba biodegradation

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

    Science.gov (United States)

    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.

  2. Preparation and characterization of biodegradable poly(vinyl alcohol)

    African Journals Online (AJOL)

    Preparation and characterization of biodegradable poly(vinyl alcohol)/starch blends. ... Their mechanical properties, biodegradability and surface morphology were estimated and studied. The poly(vinyl alcohol)/starch blends show good ... Keywords: Starch, Acetylation, Biodegradation, Poly(vinyl alcohol), Polymer blend.

  3. Polyvinyl alcohol biodegradation under denitrifying conditions

    Czech Academy of Sciences Publication Activity Database

    Marušincová, H.; Husárová, L.; Růžička, J.; Ingr, M.; Navrátil, Václav; Buňková, L.; Koutný, M.

    2013-01-01

    Roč. 84, October (2013), s. 21-28 ISSN 0964-8305 Grant - others:GA ČR(CZ) GAP108/10/0200 Institutional support: RVO:61388963 Keywords : polyvinyl alcohol * biodegradation * denitrification * waste-water treatment * anaerobic * Steroidobacter Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.235, year: 2013

  4. Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions

    International Nuclear Information System (INIS)

    Zembrzuska, Joanna; Budnik, Irena; Lukaszewski, Zenon

    2016-01-01

    Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C 12 E 9 having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C 12 E 9 as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C 12 E 9 and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C 12 E 9 , C 12 E 8 , C 12 E 7 and C 12 E 6 . Apart from the substrate, the homologues C 12 E 8 , C 12 E 7 and C 12 E 6 , being metabolites of C 12 E 9 biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C 12 E 8 COOH, C 12 E 7 COOH, C 12 E 6 COOH and C 12 E 5 COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C 12 E 9 and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a single unit. - Highlights: • Two parallel biodegradation pathways of alcohol ethoxylates have been discovered. • Apart from central

  5. Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions

    Energy Technology Data Exchange (ETDEWEB)

    Zembrzuska, Joanna, E-mail: Joanna.Zembrzuska@put.poznan.pl; Budnik, Irena, E-mail: Irena.Budnik@gmail.com; Lukaszewski, Zenon, E-mail: zenon.lukaszewski@put.poznan.pl

    2016-07-01

    Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C{sub 12}E{sub 9} having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C{sub 12}E{sub 9} as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C{sub 12}E{sub 9} and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C{sub 12}E{sub 9}, C{sub 12}E{sub 8}, C{sub 12}E{sub 7} and C{sub 12}E{sub 6}. Apart from the substrate, the homologues C{sub 12}E{sub 8}, C{sub 12}E{sub 7} and C{sub 12}E{sub 6}, being metabolites of C{sub 12}E{sub 9} biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C{sub 12}E{sub 8}COOH, C{sub 12}E{sub 7}COOH, C{sub 12}E{sub 6}COOH and C{sub 12}E{sub 5}COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C{sub 12}E{sub 9} and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a

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

    Science.gov (United States)

    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....

  7. Minimum emittance in TBA and MBA lattices

    Science.gov (United States)

    Xu, Gang; Peng, Yue-Mei

    2015-03-01

    For reaching a small emittance in a modern light source, triple bend achromats (TBA), theoretical minimum emittance (TME) and even multiple bend achromats (MBA) have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 31/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design.

  8. Physical characterization of biodegradable films based on chitosan, polyvinyl alcohol and Opuntia mucilage

    Science.gov (United States)

    This study aimed to develop and characterize biodegradable films containing mucilage, chitosan and polyvinyl alcohol (PVA) in different concentrations. The films were prepared by casting on glass plates using glycerol as plasticizer. Mechanical properties, water vapor and oxygen barrier, as well as ...

  9. Orbifolded Konishi from the mirror TBA

    Energy Technology Data Exchange (ETDEWEB)

    De Leeuw, Marius [Max-Planck-Institut fuer Gravitationsphysik, Albert-Einstein-Institute, Am Muehlenberg 1, 14476 Potsdam (Germany); Van Tongeren, Stijn J, E-mail: Marius.de.Leeuw@aei.mpg.de, E-mail: S.J.vanTongeren@uu.nl [Institute for Theoretical Physics and Spinoza Institute, Utrecht University, 3508 TD Utrecht (Netherlands)

    2011-08-12

    Starting with a discussion of the general applicability of the simplified mirror thermodynamic Bethe ansatz (TBA) equations to simple deformations of the AdS{sub 5} x S{sup 5} superstring, we proceed to study a specific type of orbifold to which the undeformed simplified TBA equations directly apply. We then use this set of equations, as well as Luescher's approach, to determine the next-to-leading-order wrapping correction to the energy of what we call the orbifolded Konishi state and show that they perfectly agree. In addition we discuss wrapping corrections to the ground-state energy of the orbifolded model under consideration.

  10. Preparation and Biodegradation of Nanocellulose Reinforced Polyvinyl Alcohol Blend Films in Bioenvironmental Media

    OpenAIRE

    Nusaiba Islam; Sharmin Jahan Proma; Ashiqur Rahman; Ashok Kumar Chakraborty

    2017-01-01

    Solution casting method was used to prepare nanocellulose reinforced polyvinyl alcohol (PVOH) from Oil palm empty fruit bunches. Different environmental test were used to investigate the biodegradability of the composite in soil and compost as well as in water and acidic solution. The morphology of the composite was investigated by scanning electron microscopy. The composite film with nanocellulose and without nanocellulose were compared, nanocellulose modified PVOH film showed more highly de...

  11. Biodegradable starch/poly (vinyl alcohol) film reinforced with titanium dioxide nanoparticles

    Science.gov (United States)

    Hejri, Zahra; Seifkordi, Ali Akbar; Ahmadpour, Ali; Zebarjad, Seyed Mojtaba; Maskooki, Abdolmajid

    2013-10-01

    Biodegradable starch/poly (vinyl alcohol)/nano-titanium dioxide (ST/PVA/nano-TiO2) nanocomposite films were prepared via a solution casting method. Their biodegradability, mechanical properties, and thermal properties were also studied in this paper. A general full factorial experimental approach was used to determine effective parameters on the mechanical properties of the prepared films. ST/PVA/TiO2 nanocomposites were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). The results of mechanical analysis show that ST/PVA films with higher contents of PVA have much better mechanical properties. In thermal analysis, it is found that the addition of TiO2 nanoparticles improves the thermal stability of the films. SEM micrographs, taken from the fracture surface of samples, illustrate that the addition of PVA makes the film softer and more flexible. The results of soil burial biodegradation indicate that the biodegradability of ST/PVA/TiO2 films strongly depends on the starch proportion in the film matrix. The degradation rate is increased by the addition of starch in the films.

  12. RK-TBA prototype RF source

    International Nuclear Information System (INIS)

    Houck, T.; Anderson, D.; Giordano, G.

    1996-01-01

    A prototype rf power source based on the Relativistic Klystron Two-Beam Accelerator (RK-TBA) concept is being constructed at the Lawrence Berkeley National Laboratory to study physics, engineering, and costing issues. The prototype is described and compared to a full scale design appropriate for driving the Next Linear Collider (NLC). Specific details of the induction core tests and pulsed power system are presented. The 1-MeV, 1.2-kA induction gun currently under construction is also described in detail

  13. Biodegradable blends of starch/polyvinyl alcohol/glycerol: multivariate analysis of the mechanical properties

    Directory of Open Access Journals (Sweden)

    Juliano Zanela

    Full Text Available Abstract The aim of the work was to study the mechanical properties of extruded starch/polyvinyl alcohol (PVA/glycerol biodegradable blends using multivariate analysis. The blends were produced as cylindrical strands by extrusion using PVAs with different hydrolysis degrees and viscosities, at two extrusion temperature profiles (90/170/170/170/170 °C and 90/170/200/200/200 °C and three conditioning relative humidities of the samples (33, 53, and 75%. The mechanical properties showed a great variability according to PVA type, as well as the extrusion temperature profile and the conditioning relative humidity; the tensile strength ranged from 0.42 to 5.40 MPa, elongation at break ranged from 10 to 404% and Young’s modulus ranged from 0.93 to 13.81 MPa. The multivariate analysis was a useful methodology to study the mechanical properties behavior of starch/PVA/glycerol blends, and it can be used as an exploratory technique to select of the more suitable PVA type and extrusion temperature to produce biodegradable materials.

  14. Biodegradable foams based on starch, polyvinyl alcohol, chitosan and sugarcane fibers obtained by extrusion

    Directory of Open Access Journals (Sweden)

    Flávia Debiagi

    2011-10-01

    Full Text Available Biodegradable foams made from cassava starch, polyvinyl alcohol (PVA, sugarcane bagasse fibers and chitosan were obtained by extrusion. The composites were prepared with formulations determined by a constrained ternary mixtures experimental design, using as variables: (X1 starch / PVA (100 - 70%, (X2 chitosan (0 - 2% and (X3 fibers from sugar cane (0 - 28%. The effects of varying proportions of these three components on foam properties were studied, as well the relationship between their properties and foam microstructure. The addition of starch/PVA in high proportions increased the expansion index and mechanical resistance of studied foams. Fibers addition improved the expansion and mechanical properties of the foams. There was a trend of red and yellow colors when the composites were produced with the highest proportions of fibers and chitosan, respectively. All the formulations were resistant to moisture content increase until 75% relative humidity of storage.

  15. Study of Biodegradability and Mechanical Properties of Polyvinyl Alcohol (PVA Reinforced Celloluse Nanofiber (CNF

    Directory of Open Access Journals (Sweden)

    shobo salehpour

    2018-02-01

    Full Text Available The aim of this study was to improve the properties of polyvinyl alcohol (PVA by using cellulose nanofibers (CNF as a reinforcement. In order to improve the compatibility and miscibility with PVA matrix, freeze drying method was applied. The nanocomposites based on PVA with values 5, 10, 20 and 30wt% of CNF were prepared by freeze-drying and the effect of CNF addition on the mechanical and dynamical mechanical properties, moisture sorption, barrier and biodegradability of the nanocomposites was studied. The tensile strength and elastic modulus of PVA films were improved by the addition of CNF. The nanocomposite with 10wt% nano-fibers had the highest tensile strength and lowest modulus of elasticity and the elongation at break. The results indicated that the storage modulus (E′ of PVA was considerably improved with the introduction of CNF into - polymer matrix. The water vapor permeability decreased from 7.31 to 2.1×10-7 g/m. h. Pa as the CNF percentage increased from 0 to 30%. Also the presence of cellulose nanofibers improved moisture sorption of polyvinyl alcohol. The weight loss of PVA films increased 60% with addition of 30wt% CNF after 90 days of exposure in soil

  16. A lifetime as TBA in Uganda.

    Science.gov (United States)

    Kanabahita, C

    1993-01-01

    A 64-year old traditional birth attendant (TBA), Zowe Namasiga, in Kyobe county in the Rakai district of Uganda, delivered her 1st baby when she was 12 years old. She learned how to deliver babies by watching her father deliver babies. She married at 14 and had 7 children of her own. She delivered 2 of her own children all alone. She attended a 1-week workshop for TBAs hosted by World Vision International and attended by 52 other TBAs. The medical services that exist in rural Uganda and tend to be of low quality. The leading problem for pregnant women in Rakai district in insufficient transport. The closest clinic is 8 miles away from where the workshop was held, but it has no midwives and the staff are not trained to deliver babies. The ratio of midwife to women of reproductive age in Rakai district is 1:5000. Ms. Namasiga has to refer high risk patients to Kitovu Hospital, a distance of 62 km. In the workshop, illustrations of male and female reproductive systems helped them learn that the uterus is not connected to the digestive system. The TBAs learned about the importance of hygiene and of encouraging women to seek prenatal care and to receive tetanus toxoid injections. The workshop taught them how to identify high risk women and to refer them to the hospital. Few women go to the hospital, though, because town midwives do not treat them kindly. One participant described how she keeps premature babies alive: wraps them and places them in a circle of 5-liter metal cans filled with warm water. TBAs are concerned about AIDS. In fact, the last grandchild Ms. Namasiga delivered was born to parents with AIDS. She delivers babies with her bare hands, but now asks for payment so she can buy gloves to protect her cracked hands. Most TBAs care for AIDS orphans. TBAs assist at 90% of deliveries in this rural district.

  17. 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

    Energy Technology Data Exchange (ETDEWEB)

    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

  18. Anaerobic degradation of a mixture of MtBE, EtBE, TBA, and benzene under different redox conditions.

    Science.gov (United States)

    van der Waals, Marcelle J; Pijls, Charles; Sinke, Anja J C; Langenhoff, Alette A M; Smidt, Hauke; Gerritse, Jan

    2018-04-01

    The increasing use of biobased fuels and fuel additives can potentially change the typical fuel-related contamination in soil and groundwater. Anaerobic biotransformation of the biofuel additive ethyl tert-butyl ether (EtBE), as well as of methyl tert-butyl ether (MtBE), benzene, and tert-butyl alcohol (TBA, a possible oxygenate metabolite), was studied at an industrially contaminated site and in the laboratory. Analysis of groundwater samples indicated that in the field MtBE was degraded, yielding TBA as major product. In batch microcosms, MtBE was degraded under different conditions: unamended control, with medium without added electron acceptors, or with ferrihydrite or sulfate (with or without medium) as electron acceptor, respectively. Degradation of EtBE was not observed under any of these conditions tested. TBA was partially depleted in parallel with MtBE. Results of microcosm experiments with MtBE substrate analogues, i.e., syringate, vanillate, or ferulate, were in line with the hypothesis that the observed TBA degradation is a cometabolic process. Microcosms with ferulate, syringate, isopropanol, or diethyl ether showed EtBE depletion up to 86.5% of the initial concentration after 83 days. Benzene was degraded in the unamended controls, with medium without added electron acceptors and with ferrihydrite, sulfate, or chlorate as electron acceptor, respectively. In the presence of nitrate, benzene was only degraded after addition of an anaerobic benzene-degrading community. Nitrate and chlorate hindered MtBE, EtBE, and TBA degradation.

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

    Science.gov (United States)

    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...

  20. Alyssum homolocarpum seed gum-polyvinyl alcohol biodegradable composite film: Physicochemical, mechanical, thermal and barrier properties.

    Science.gov (United States)

    Monjazeb Marvdashti, Leila; Koocheki, Arash; Yavarmanesh, Masoud

    2017-01-02

    Films made from Alyssum homolocarpum seeds gum (AHSG) have poor mechanical and barrier (to oxygen) properties. In the present study poly vinyl alcohol (PVA) was used to improve the physicochemical properties of AHSG films. Results indicated that the addition of PVA significantly increased the moisture content, solubility, elongation at break (EB) and transparency while it decreased the density, oxygen permeability, chroma, water contact angle and Young modulus of AHSG based films. Films with higher AHSG to PVA ratios had lower water vapor permeability (WVP). The light barrier measurements presented low values of transparency at 600nm for PVA/AHSG films, indicating that films were very transparent while they had excellent barrier properties against UV light. Results for FTIR, DSC and SEM showed a clear interaction between PVA and AHSG, forming a new material. These results indicated that PVA/AHSG blend films had good compatibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

  1. Preparation and characterization of polyvinyl alcohol hydrogels crosslinked by biodegradable polyurethane for tissue engineering of cartilage

    International Nuclear Information System (INIS)

    Bonakdar, Shahin; Emami, Shahriar Hojjati; Shokrgozar, Mohammad Ali; Farhadi, Afshin; Ahmadi, Seyed Amir Hoshiar; Amanzadeh, Amir

    2010-01-01

    Polyurethane was prepared from hexamethylene diisocyanate (HMDI) and polycaprolactone diol (PCL) with stoichiometry ratio of two in a reactor to form prepolymer. Polyvinyl alcohol (PVA) at PVA/prepolymer ratios of 8, 4, 2 and 1 was crosslinked with the former degradable polyester polyurethane. Fourier transform infrared (FTIR) was employed to confirm polyurethane formation during the course of reactions. FTIR spectrum revealed bands at 1729-1733 cm -1 and 3347-3340 cm -1 which indicates carbonyl and NH of amine groups, respectively. Polyurethane formation was also confirmed by the absence of the isocyanate peaks (NCO) at 2270 cm -1 . Dynamic mechanical thermal analysis (DMTA) showed that by increasing prepolymer concentration glass transition temperature decreases from 26 deg. C for PVA to 19 deg. C for sample with PVA/prepolymer ratio of 4 and then it rises up to 31 deg. C. Water uptake measurements illustrated about four fold reduction in swelling ratio of PVA after crosslinking and the sample with equal amounts of PVA and PPU had water uptake of 100%, close to that of a natural cartilage and much less than PVA (425%). All samples had compressive modulus in the range of the articular cartilage (1.9-14.4 MPa). The morphology of the isolated cells on the samples was evaluated by scanning electron microscopy (SEM) and revealed cell attachment and proliferation. The cell viability (3-4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, MTT) and GAG expression (dimethylmethylene blue, DMMB) assays with human chondrocytes on the sample with PVA/prepolymer ratio of one showed about 14 and 33% increase in cell viability and GAG expression after 14 days of culture compare to the PVA, respectively.

  2. Terrorist and Organized Crime Groups in the Tri-Border Area (TBA) of South America

    National Research Council Canada - National Science Library

    Hudson, Rex

    2003-01-01

    .... This is unavoidable because the TBA cannot be discussed entirely as an isolated entity. Based entirely on open sources, this assessment has made extensive use of books, journal articles, and other reports available in the Library of Congress collections...

  3. PREPARATION AND CHARACTERIZATION OF BIODEGRADABLE ...

    African Journals Online (AJOL)

    Dr Abdusalam

    Keywords: Starch, Acetylation, Biodegradation, Poly(vinyl alcohol), Polymer blend. INTRODUCTION. Non-biodegradable polymers, such as polyethene, polypropane, poly(vinylchloride) etc have excellent mechanical properties such as tensile strength, tensile strain, bursting strength and tear strength (Hay and. Sharma.

  4. Clinical significance of changes of serum TBA, CG, HA levels in neonate with parenteral nutrition

    International Nuclear Information System (INIS)

    Huang Weiliang; Zhou Jiongying; Zhang Xiaoyi; Lv Weihua; Ma Yunbao; He Qizhi

    2010-01-01

    Objective: To study the clinical significance of changes of serum levels of TBA, CG, HA in neonate with parenteral nutrition. Methods: Serum total bile acid (TBA, with biochemistry) and CG, HA (with RIA) contents were measured in 52 neonates (full-term 32, preterm 20) with parenteral nutrition and 28 neonates (full-term 16, preterm 12) without parenteral nutrition (as controls). Results: Before parenteral nutrition,the serum TBA, CG and HA levels in full-term neonates were not significantly different from those in the controls (P>0.05). After parenteral nutrition,serum levels were significantly higher than those before parenteral nutrition (P<0.01). The levels in pre-term neonates were significantly higher after parenteral nutrition than those in full-term neonates (P<0.05). Conclusion: Long term parenteral nutrition might be harmful to hepatic and gall bladder function in neonates especially in premature ones. (authors)

  5. Re-examining authoritative knowledge in the design and content of a TBA training in India.

    Science.gov (United States)

    Saravanan, Sheela; Turrell, Gavin; Johnson, Helen; Fraser, Jennifer; Patterson, Carla Maree

    2012-02-01

    Since the 1990s, the TBA training strategy in developing countries has been increasingly seen as ineffective and hence its funding was subsequently reallocated to providing skilled attendants during delivery. The ineffectiveness of training programmes is blamed on TBAs lower literacy, their inability to adapt knowledge from training and certain practices that may cause maternal and infant health problems. However most training impact assessments evaluate post-training TBA practices and do not assess the training strategy. There are serious deficiencies noted in information on TBA training strategy in developing countries. The design and content of the training is vital to the effectiveness of TBA training programmes. We draw on Jordan's concept of 'authoritative knowledge' to assess the extent to which there is a synthesis of both biomedical and locally practiced knowledge in the content and community involvement in the design of TBA a training programme in India. The implementation of the TBA training programme at the local level overlooks the significance of and need for a baseline study and needs assessment at the local community level from which to build a training programme that is apposite to the local mother's needs and that fits within their 'comfort zone' during an act that, for most, requires a forum in which issues of modesty can be addressed. There was also little scope for the training to be a two way process of learning between the health professionals and the TBAs with hands-on experience and knowledge. The evidence from this study shows that there is an overall 'authority' of biomedical over traditional knowledge in the planning and implementation process of the TBA training programme. Certain vital information was not covered in the training content including advice to delay bathing babies for at least six hours after birth, to refrain from applying oil on the infant, and to wash hands again before directly handling mother or infant. Information on

  6. Biodegradable Sonobuoy Decelerators

    Science.gov (United States)

    2015-06-01

    agent. Samples were also analyzed for heavy metals which found concentrations below the toxicity threshold, ruling out metals contamination during...unlimited” 13. SUPPLEMENTARY NOTES 14. ABSTRACT In response to environmental concerns regarding nylon decelerators from sonobuoys polluting the oceans...readiness point for technology transition. 15. SUBJECT TERMS biodegrade, decelerator, sonobuoy, polyvinyl alcohol, polyhydroxyalkanoate, marine

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

    International Nuclear Information System (INIS)

    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

  8. In vitro and in vivo study to the biocompatibility and biodegradation of hydroxyapatite/poly(vinyl alcohol)/gelatin composite.

    NARCIS (Netherlands)

    Wang, M.; Li, Y.; Wu, J.; Xu, F.; Zuo, Y.; Jansen, J.A.

    2008-01-01

    A novel porous composite material composed of hydroxyapatite, poly(vinyl alcohol) (PVA), and gelatin (Gel) was fabricated by emulsification. Scanning electron microscopy showed that the material had a well-interconnected porous structure including many macropores (100-500 microm) and micropores

  9. Alcohol

    Science.gov (United States)

    ... because that's how many accidents occur. 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 ...

  10. Alcohol

    Science.gov (United States)

    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 ...

  11. Alcohol

    International Nuclear Information System (INIS)

    Navarro Junior, L.

    1988-01-01

    The alcohol production as a secondary energy source, the participation of the alcohol in Brazilian national economic and social aspects are presented. Statistical data of alcohol demand compared with petroleum by-products and electricity are also included. (author)

  12. Biodegradable Polymers

    OpenAIRE

    Vroman, Isabelle; Tighzert, Lan

    2009-01-01

    Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). In general natural polymers offer fewer advantages than synthetic polymers. ...

  13. UJI AKTIVITAS ANTIOKSIDAN HASIL DEGRADASI LIGNIN DARI SERBUK GERGAJI KAYU KALBA (Albizia falcataria) DENGAN METODE TBA (Thio Barbituric Acid)

    OpenAIRE

    Undri Rastuti; Purwati

    2010-01-01

    Antioxidants are compounds that can delay, retard or inhibit the oxidation reaction. Lignin is a natural polymer consisting of monomeric substituted phenols. Wood lignin degradation Kalba (Albizia falcataria) yields substituted phenol. The purpose of this study was to test the antioxidant activity of compounds of lignin degradation products Kalba using TBA (Thiobarbituric Acid). Wood lignin degradation products Kalba tested antioxidant activity using the TBA method. Phase test phase of this a...

  14. Tensile and Water Absorption Properties of Biodegradable Composites Derived from Cassava Skin/ Polyvinyl Alcohol with Glycerol as Plasticizer

    International Nuclear Information System (INIS)

    Dayangku Intan Munthoub; Wan Aizan Wan Abdul Rahman

    2011-01-01

    Natural organic and abundant resources biopolymers received more attention due to their low cost, availability and degradability after usage. Cassava skin was used as natural fillers to the polyvinyl alcohol (PVA). Cassava skin/ poly vinyl alcohol blends were compounded using melt extrusion twin screw extruder and test samples were prepared using the compression method. Various ratios of cassava skin and glycerol were investigated to identify suitable composition based on the water absorption and tensile properties. The water absorption of the cassava skins/ PVA samples increased at higher composition of cassava skin due to their hydrophilic properties but decrease with glycerol content. The strength of the cassava skins/ PVA samples increased with the higher composition of cassava skin up to 70 wt % while gradually decreased with the increasing composition of glycerol. The Young modulus increased with glycerol content but decreased with fibre loading up to 70 wt %. Elongation at break decreased with fibre loading and glycerol up to 70 wt % and 30 phr, respectively. (author)

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

    Science.gov (United States)

    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.

  16. Mass transfer analysis for terephthalic acid biodegradation by ...

    African Journals Online (AJOL)

    Biodegradation of terephthalic acid (TA) by polyvinyl alcohol (PVA)-alginate immobilized Pseudomonas sp. was carried out in a packed-bed reactor. The effect of inlet TA concentration on biodegradation was investigated at 30°C, pH 7 and flow rate of 20 ml/min. The effects of flow rate on mass transfer and biodegradation ...

  17. Alcohol

    OpenAIRE

    World Bank

    2003-01-01

    Alcohol abuse is one of the leading causes of death and disability worldwide. Alcohol abuse is responsible for 4 percent of global deaths and disability, nearly as much as tobacco and five times the burden of illicit drugs (WHO). In developing countries with low mortality, alcohol is the leading risk factor for males, causing 9.8 percent of years lost to death and disability. Alcohol abuse...

  18. Formation of zinc-peptide spherical microparticles during lyophilization from tert-butyl alcohol/water co-solvent system.

    Science.gov (United States)

    Qian, Feng; Ni, Nina; Chen, Jia-Wen; Desikan, Sridhar; Naringrekar, Vijay; Hussain, Munir A; Barbour, Nancy P; Smith, Ronald L

    2008-12-01

    To understand the mechanism of spherical microparticle formation during lyophilizing a tert-Butyl alcohol (TBA)/water solution of a zinc peptide adduct. A small peptide, PC-1, as well as zinc PC-1 at (3:2) and (3:1) ratios, were dissolved in 44% (wt.%) of TBA/water, gradually frozen to -50 degrees C over 2 h ("typical freezing step"), annealed at -20 degrees C for 6 h ("annealing step"), and subsequently lyophilized with primary and secondary drying. Zinc peptide (3:1) lyophile was also prepared with quench cooling instead of the typical freezing step, or without the annealing step. Other TBA concentrations, i.e., 25%, 35%, 54% and 65%, were used to make the zinc peptide (3:1) adduct lyophile with the typical freezing and annealing steps. The obtained lyophile was analyzed by Scanning Electron Microscopy (SEM). The zinc peptide solutions in TBA/water were analyzed by Differential Scanning Calorimeter (DSC). The surface tension of the TBA/water co-solvent system was measured by a pendant drop shape method. With typical freezing and annealing steps, the free peptide lyophile showed porous network-like structure that is commonly seen in lyophilized products. However, with increasing the zinc to peptide ratio, uniform particles were gradually evolved. Zinc peptide (3:1) adduct lyophiles obtained from 25%, 35% and 44% TBA exhibit a distinctive morphology of uniform and spherical microparticles with diameters of approximately 3-4 microm, and the spherical zinc peptide particles are more predominant when the TBA level approaches 20%. Adopting quench cooling in the lyophilization cycle leads to irregular shape fine powders, and eliminating the annealing step causes rough particles surface. When TBA concentration increases above 54%, the lyophiles demonstrate primarily irregular shape particles. A proposed mechanism of spherical particle formation of the 3:1 zinc peptide encompasses the freezing of a TBA/water solution (20-70% TBA) causing the formation of a TBA hydrate

  19. Excess Molar Volume Of Binarymixtures From Iso-Propyl Alcohol ...

    African Journals Online (AJOL)

    In this work, binary mixtures from Tertiary-Butyl alcohol (TBA), Toluene (TOL) and Iso-Propyl alcohol (IPA) were prepared at 298K. The mixtures physical properties which includes densities of mixtures (ρ) and pure components (ρI) and mole fractions of components (x) were equally measured at 298K. Excess molar volumes ...

  20. Structural transition in alcohol-water binary mixtures: A ...

    Indian Academy of Sciences (India)

    The strengthening of the hydrogen bonding (H-bond) network as well as transition from the tetrahedral-like water network to the zigzag chain structure of alcohol upon increasing the alcohol concentration in ethanol-water and tertiary butanol (TBA) - water mixtures have been studied by using both steady state and time ...

  1. Alcohol

    NARCIS (Netherlands)

    Hendriks, H.F.; Tol, A. van

    2005-01-01

    Alcohol consumption affects overall mortality. Light to moderate alcohol consumption reduces the risk of coronary heart disease; epidemiological, physiological and genetic data show a causal relationship. Light to moderate drinking is also associated with a reduced risk of other vascular diseases

  2. Oil biodegradation

    NARCIS (Netherlands)

    Rahsepar, Shokouhalsadat; Langenhoff, Alette A.M.; Smit, Martijn P.J.; Eenennaam, van Justine S.; Murk, Tinka; Rijnaarts, Huub H.M.

    2017-01-01

    During the Deepwater Horizon (DwH) oil spill, interactions between oil, clay particles and marine snow lead to the formation of aggregates. Interactions between these components play an important, but yet not well understood, role in biodegradation of oil in the ocean water. The aim of this study

  3. Alcohol

    OpenAIRE

    Philip J. Cook; Michael J. Moore

    1999-01-01

    Excess drinking is associated with lost productivity, accidents, disability, early death, crime, neglect of family responsibilities, and personality deterioration. These and related concerns have justified special restrictions on alcoholic-beverage commerce and consumption. The nature and extent of government involvement in this arena vary widely over time and place, and are often controversial. Economists have contributed to the evaluation of alcohol policy through empirical work on the effe...

  4. 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.

    Directory of Open Access Journals (Sweden)

    Guadalupe Alfonso-Gordillo

    Full Text Available 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.

  5. Anaerobic biodegradability of macropollutants

    DEFF Research Database (Denmark)

    Angelidaki, Irini

    2002-01-01

    A variety of test procedures for determination of anaerobic biodegradability has been reported. This paper reviews the methods developed for determination of anaerobic biodegradability of macro-pollutants. Anaerobic biodegradability of micro-pollutants is not included. Furthermore, factors...

  6. Biodegradação de alcoóis, ftalatos e adipatos em um solo tropical contaminado Biodegradation of alcohol, phthalates and adipates in a tropical soil

    Directory of Open Access Journals (Sweden)

    Ieda Domingues Ferreira

    2010-01-01

    Full Text Available The adipic and phthalic acid esters are plasticizers, have low water solubility, high partition octanol/water coefficients (Kow and accumulate in soil and sediments. These compounds are considered teratogenic, carcinogenic and endocrine disruptors chemicals. This study evaluated the bioremediation of tropical soil contaminated with plasticizers process wastes, in aerobic conditions, with and without introduction of acclimated bacteria. It was selected 200 kg of contaminated tropical soil for the biodegradation study. The plasticizers concentrations in soil ranged between 153 mgDOA/kg up to 15552 mgDIDP/kg and after 90 days of biodegradation, the lower removal efficiencies were 72% with a 1-2 log simultaneous bacterial growth.

  7. Biodegradation and bioremediation

    DEFF Research Database (Denmark)

    Albrechtsen, H.-J.

    1996-01-01

    Anmeldelse af Alexander,M.: Biodegradation and bioremediation. Academic Press, Sandiego, USA, 1994......Anmeldelse af Alexander,M.: Biodegradation and bioremediation. Academic Press, Sandiego, USA, 1994...

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

    Directory of Open Access Journals (Sweden)

    Elena Vlad

    2012-01-01

    Full Text Available 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.

  9. Cobalt-chitosan: Magnetic and biodegradable heterogeneous ...

    Indian Academy of Sciences (India)

    A novel and biodegradable cobalt-chitosan as a magnetic heterogeneous catalyst was synthesized and characterized by XPS, FT-IR, EDX and TEM. Catalytic performance of cobalt- chitosan was tested by aerobic oxidation of alkyl arenes and alcohols. The results show that the catalyst exhibits excellent conversion for ...

  10. Cobalt-chitosan: Magnetic and biodegradable heterogeneous ...

    Indian Academy of Sciences (India)

    Abstract. A novel and biodegradable cobalt-chitosan as a magnetic heterogeneous catalyst was synthesized and characterized by XPS, FT-IR, EDX and TEM. Catalytic performance of cobalt- chitosan was tested by aerobic oxidation of alkyl arenes and alcohols. The results show that the catalyst exhibits excellent ...

  11. Cobalt-chitosan: Magnetic and biodegradable heterogeneous ...

    Indian Academy of Sciences (India)

    Cobalt-chitosan: Magnetic and biodegradable catalyst. 1931. Table 3. Effects of the solvent, temperature and base on oxidation of phenylethyl alcohol using cobalt-chitosan.a. Entry. Solvent. Temperature. Base. Yield (%) b. 1. DMF. 100. K2CO3. 60. 2. DMF. 100. KOH. 60. 3. CH3CN. 80. K2CO3. 65. 4. H2O reflux. KOH. 10. 5.

  12. UJI AKTIVITAS ANTIOKSIDAN HASIL DEGRADASI LIGNIN DARI SERBUK GERGAJI KAYU KALBA (Albizia falcataria DENGAN METODE TBA (Thio Barbituric Acid

    Directory of Open Access Journals (Sweden)

    Undri Rastuti

    2010-11-01

    Full Text Available Antioxidants are compounds that can delay, retard or inhibit the oxidation reaction. Lignin is a natural polymer consisting of monomeric substituted phenols. Wood lignin degradation Kalba (Albizia falcataria yields substituted phenol. The purpose of this study was to test the antioxidant activity of compounds of lignin degradation products Kalba using TBA (Thiobarbituric Acid. Wood lignin degradation products Kalba tested antioxidant activity using the TBA method. Phase test phase of this antioxidant activity is sample preparation, determination of the maximum wavelength, determination of equilibrium time, absorbance measurements and determination of the percentage of inhibition. The wavelength maximum for BHT test solution was obtained at 530 nm. The stability of absorbance achieved after 80 minutes equilibrium time. BHT test solution and sample solution containing the degradation of lignin 0.10% (w/v increased but not as sharp as the absorbance of control, this suggests that the degradation of wood lignin Kalba have activity as an antioxidant, which relative minimize 13,70 % compare with BHT.

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

    International Nuclear Information System (INIS)

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

    2014-01-01

    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. - Highlights: • Poly(lactic acid)/poly(vinyl acetate-co-vinyl alcohol) blends were prepared as new packaging film. • The blends are superior to PLA in oxygen gas barrier property. • The blends are suitable for gamma ray sterilization and maintain useful mechanical properties. • The blends are perfectly transparent

  14. Biodegradation behaviors of cellulose nanocrystals -PVA nanocomposites

    Directory of Open Access Journals (Sweden)

    Mahdi Rohani

    2014-11-01

    Full Text Available In this research, biodegradation behaviors of cellulose nanocrystals-poly vinyl alcohol nanocomposites were investigated. Nanocomposite films with different filler loading levels (3, 6, 9 and 12% by wt were developed by solvent casting method. The effect of cellulose nanocrystals on the biodegradation behaviors of nanocomposite films was studied. Water absorption and water solubility tests were performed by immersing specimens into distilled water. The characteristic parameter of diffusion coefficient and maximum moisture content were determined from the obtained water absorption curves. The water absorption behavior of the nanocomposites was found to follow a Fickian behavior. The maximum water absorption and diffusion coefficients were decreased by increasing the cellulose nanocrystals contents, however the water solubility decrease. The biodegradability of the films was investigated by immersing specimens into cellulase enzymatic solution as well as by burial in soil. The results showed that adding cellulose nanocrystals increase the weight loss of specimens in enzymatic solution but decrease it in soil media. The limited biodegradability of specimens in soil media attributed to development of strong interactions with solid substrates that inhibit the accessibility of functional groups. Specimens with the low degree of hydrolysis underwent extensive biodegradation in both enzymatic and soil media, whilst specimens with the high degree of hydrolysis showed recalcitrance to biodegradation under those conditions.

  15. Biobased and biodegradable polymer nanocomposites

    Science.gov (United States)

    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

  16. Preparation of liposomes containing zedoary turmeric oil using freeze-drying of liposomes via TBA/water cosolvent systems and evaluation of the bioavailability of the oil.

    Science.gov (United States)

    Yang, Zhiwen; Yu, Songlin; Fu, Dahua

    2010-02-01

    The purpose of this study was to enhance the absorption of zedoary turmeric oil (ZTO) in vivo and develop new formulations of a water-insoluble oily drug. This study described a method for preparing ZTO liposomes, which involved freeze-drying (FD) of liposomes with TBA/water cosolvent systems. The TBA/water cosolvent systems were used to investigate a feasible method of liposomes manufacture; the two factors, sugar/lipid mass ratio and TBA content (concentration), of the preparation process were evaluated in this study. The results showed that the addition of TBA content could significantly enhance the sublimation of ice resulting in short FD cycles time, and reduce the entrapment efficiency of liposomes. In addition, the residual TBA solvents levels were determined to be less than 0.37% under all optimum formulations and processing conditions. Several physical properties of liposomes were examined by H-600 transmission electron microscope (TEM) and zetamaster analyser system. The results revealed that the liposomes were smooth and spherical with an average particle size of 457 +/- 7.8 nm and the zeta potential was more than 3.65 Mv. The bioavailability of the liposomes was evaluated in rabbits, compared with the conventional self-emulsifying formulation for oral administration. Compared with the conventional self-emulsifying formulation, the plasma concentration-time profiles with improved sustained-release characteristics were achieved after oral administration of the liposomes with a bioavailability of 257.7% (a good strategy for improving the bioavailability of an oily drug). In conclusion, the present experimental findings clearly demonstrated the usefulness of ZTO liposome vesicles in improving therapeutic efficacy by enhancing oral bioavailability. Our study offered an alternative method for designing sustained-release preparations of oily drugs.

  17. Alcoholism and Alcohol Abuse

    Science.gov (United States)

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

  18. Predicting methyl tert-butyl ether, tert-butyl formate, and tert-butyl alcohol levels in the environment using the fugacity approach.

    Science.gov (United States)

    Arp, Hans Peter H; Fenner, Kathrin; Schmidt, Torsten C

    2005-05-01

    Through its extensive use as a fuel oxygenate, methyl tert-butyl ether (MTBE) is found nearly ubiquitouslythroughout the environment. To better understand the environmental fate of MTBE, fugacity models are commonly used. However, models developed by the scientific community and by governmental bodies differ in their predictions of relative MTBE concentrations for relevant environmental compartments and of seasonal concentration variations; further, to date they have not considered the formation of transformation products. In this study, the sensitivity of predicted environmental concentrations of MTBE and its two major degradation products, tert-butyl formate (TBF) and tert-butyl alcohol (TBA), to all types of model input parameters is analyzed in a probabilistic sensitivity analysis. This analysis allowed for an assessment of the most influential parameters for predicting soil, water, and air concentrations and thereby provided insight into why previous modeling studies on MTBE differed. Further, the information from the sensitivity analysis was used to parametrize a multispecies transformation model for predicting European concentration levels of MTBE and, for the first time, TBF and TBA. Water and air concentrations of MTBE predicted with the transformation model were in good agreement with measurements of environmental samples. No studies are available on environmental TBF and TBA levels to compare with model predictions; however, the modeling results indicate that, in the water phase, TBA concentrations may reach appreciable levels. One major uncertainty identified regarding the prediction of TBA levels was the fraction of TBA formed from atmospheric MTBE and TBF.

  19. Grey water biodegradability.

    Science.gov (United States)

    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. Biodegradable modified Phba systems

    International Nuclear Information System (INIS)

    Aniscenko, L.; Dzenis, M.; Erkske, D.; Tupureina, V.; Savenkova, L.; Muizniece - Braslava, S.

    2004-01-01

    Compositions as well as production technology of ecologically sound biodegradable multicomponent polymer systems were developed. Our objective was to design some bio plastic based composites with required mechanical properties and biodegradability intended for use as biodegradable packaging. Significant characteristics required for food packaging such as barrier properties (water and oxygen permeability) and influence of γ-radiation on the structure and changes of main characteristics of some modified PHB matrices was evaluated. It was found that barrier properties were plasticizers chemical nature and sterilization with γ-radiation dependent and were comparable with corresponding values of typical polymeric packaging films. Low γ-radiation levels (25 kGy) can be recommended as an effective sterilization method of PHB based packaging materials. Purposely designed bio plastic packaging may provide an alternative to traditional synthetic packaging materials without reducing the comfort of the end-user due to specific qualities of PHB - biodegradability, Biocompatibility and hydrophobic nature

  1. UV absorption spectra, kinetics and mechanism for alkyl and alkyl peroxy radicals originating from t-butyl alcohol

    DEFF Research Database (Denmark)

    Langer, S.; Ljungström, E.; Sehested, J.

    1994-01-01

    Alkyl and alkyl peroxy radicals from 1-butyl alcohol (TBA), HOC (CH3)2CH2. and HOC(CH3)2CH2O2. have been studied in the ps phase at 298 K. Two techniques were used: pulse radiolysis UV absorption to measure the spectra and kinetics, and long path-length Fourier transform infrared spectroscopy (FTIR......) and k(HOC(CH3)2CH2O2. + NO2) were determined to be (4.9 +/- 0.9) X 10(-12) and (6.7 +/- 0.9) x 10(-12) cm3 molecule-1 s-1, respectively. In the FTIR experiments products were studied using chlorine-initiated oxidation in TBA/N2/Cl2 and TBA/N2/O2/Cl2 mixtures....

  2. Editorial: Biodegradable Materials

    Directory of Open Access Journals (Sweden)

    Carl Schaschke

    2014-11-01

    Full Text Available 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.

  3. Biodegradable Materials for Nonwovens

    Science.gov (United States)

    Demand for nonwovens is increasing globally, particularly in the disposable products area. As the consumption of nonwoven products with short life increases, the burden on waste disposal also rises. In this context, biodegradable nonwovens become more important today and for the future. Several new ...

  4. Alcohol Alert

    Science.gov (United States)

    ... of Alcohol Consumption Alcohol's Effects on the Body Alcohol Use Disorder Fetal Alcohol Exposure Support & Treatment Alcohol Policy Special ... 466 KB] No. 81: Exploring Treatment Options for Alcohol Use Disorders [ PDF - 539K] No. 80: Alcohol and HIV/AIDS: ...

  5. Characterization and aerobic biodegradation of selected monoterpenes

    Energy Technology Data Exchange (ETDEWEB)

    Misra, G.; Pavlostathis, S.G.; Li, J.; Purdue, E.M. [Georgia Institute of Technology, Atlanta, GA (United States)

    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.

  6. Biodegradation of Cyanuric Acid

    Science.gov (United States)

    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

  7. Absorbable and biodegradable polymers

    CERN Document Server

    Shalaby, Shalaby W

    2003-01-01

    INTRODUCTION NOTES: Absorbable/Biodegradable Polymers: Technology Evolution. DEVELOPMENT AND APPLICATIONOF NEW SYSTEMS: Segmented Copolyesters with Prolonged Strength Retention Profiles. Polyaxial Crystalline Fiber-Forming Copolyester. Polyethylene Glycol-Based Copolyesters. Cyanoacrylate-Based Systems as Tissue Adhesives. Chitosan-Based Systems. Hyaluronic Acid-Based Systems. DEVELOPMENTS IN PREPARATIVE, PROCESSING, AND EVALUATION METHODS: New Approaches to the Synthesis of Crystalline. Fiber-Forming Aliphatic Copolyesters. Advances in Morphological Development to Tailor the Performance of Me

  8. Modeling Biodegradation of Nonylphenol

    International Nuclear Information System (INIS)

    Jahan, Kauser; Ordonez, Raul; Ramachandran, Ravi; Balzer, Shira; Stern, Michael

    2008-01-01

    Nonylphenol is the primary breakdown product of nonylphenol ethoxylates, a certain class of nonionic surfactants. Nonylphenol has been found to be toxic to aquatic organisms and has been suspected of being harmful to humans due to its xenoestrogenic properties. Although there are known releases of nonylphenol to the environment, there is a lack of data describing the extent of biodegradation. This study thus focuses on much needed information on the biodegradation kinetics of nonylphenol. Oxygen uptake, cell growth and nonylphenol removal data were collected using batch reactors in an electrolytic respirometer. Nonylphenol removal, cell growth and substrate removal rates were modeled by the Monod, Haldane, Aiba, Webb, and Yano equations. The differential equations were solved by numerical integration to simulate cell growth, substrate removal, and oxygen uptake as a function of time. All models provided similar results with the Haldane model providing the best fit. The values of the kinetic parameters and the activation energy for nonylphenol were determined. These values can be used for predicting fate and transport of nonylphenol in the environment. The validity of applying each model to the biodegradation of nonylphenol was analyzed by computing the R 2 values of each equation

  9. Biodegradable packaging materials : case: PLA

    OpenAIRE

    Jama, Mohamed

    2017-01-01

    The main aim of this bachelor thesis was to investigate the possibility of biodegradable packaging materials. Plastics and other non-degradable packaging materials have been used for many years and they have a negative impact on the environment since they do not degrade. Different research methods are used to get authentic results, which simplifies using biodegradable packaging materials. There were two biodegradability testing methods, which has been applied to this task:-, testing biode...

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

    Science.gov (United States)

    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.

  11. Biodegradable Piezoelectric Force Sensor.

    Science.gov (United States)

    Curry, Eli J; Ke, Kai; Chorsi, Meysam T; Wrobel, Kinga S; Miller, Albert N; Patel, Avi; Kim, Insoo; Feng, Jianlin; Yue, Lixia; Wu, Qian; Kuo, Chia-Ling; Lo, Kevin W-H; Laurencin, Cato T; Ilies, Horea; Purohit, Prashant K; Nguyen, Thanh D

    2018-01-30

    Measuring vital physiological pressures is important for monitoring health status, preventing the buildup of dangerous internal forces in impaired organs, and enabling novel approaches of using mechanical stimulation for tissue regeneration. Pressure sensors are often required to be implanted and directly integrated with native soft biological systems. Therefore, the devices should be flexible and at the same time biodegradable to avoid invasive removal surgery that can damage directly interfaced tissues. Despite recent achievements in degradable electronic devices, there is still a tremendous need to develop a force sensor which only relies on safe medical materials and requires no complex fabrication process to provide accurate information on important biophysiological forces. Here, we present a strategy for material processing, electromechanical analysis, device fabrication, and assessment of a piezoelectric Poly-l-lactide (PLLA) polymer to create a biodegradable, biocompatible piezoelectric force sensor, which only employs medical materials used commonly in Food and Drug Administration-approved implants, for the monitoring of biological forces. We show the sensor can precisely measure pressures in a wide range of 0-18 kPa and sustain a reliable performance for a period of 4 d in an aqueous environment. We also demonstrate this PLLA piezoelectric sensor can be implanted inside the abdominal cavity of a mouse to monitor the pressure of diaphragmatic contraction. This piezoelectric sensor offers an appealing alternative to present biodegradable electronic devices for the monitoring of intraorgan pressures. The sensor can be integrated with tissues and organs, forming self-sensing bionic systems to enable many exciting applications in regenerative medicine, drug delivery, and medical devices.

  12. Thermodynamic Analysis of Biodegradation Pathways

    Science.gov (United States)

    Finley, Stacey D.; Broadbelt, Linda J.

    2014-01-01

    Microorganisms provide a wealth of biodegradative potential in the reduction and elimination of xenobiotic compounds in the environment. One useful metric to evaluate potential biodegradation pathways is thermodynamic feasibility. However, experimental data for the thermodynamic properties of xenobiotics is scarce. The present work uses a group contribution method to study the thermodynamic properties of the University of Minnesota Biocatalysis/Biodegradation Database. The Gibbs free energies of formation and reaction are estimated for 914 compounds (81%) and 902 reactions (75%), respectively, in the database. The reactions are classified based on the minimum and maximum Gibbs free energy values, which accounts for uncertainty in the free energy estimates and a feasible concentration range relevant to biodegradation. Using the free energy estimates, the cumulative free energy change of 89 biodegradation pathways (51%) in the database could be estimated. A comparison of the likelihood of the biotransformation rules in the Pathway Prediction System and their thermodynamic feasibility was then carried out. This analysis revealed that when evaluating the feasibility of biodegradation pathways, it is important to consider the thermodynamic topology of the reactions in the context of the complete pathway. Group contribution is shown to be a viable tool for estimating, a priori, the thermodynamic feasibility and the relative likelihood of alternative biodegradation reactions. This work offers a useful tool to a broad range of researchers interested in estimating the feasibility of the reactions in existing or novel biodegradation pathways. PMID:19288443

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Shanshan Li

    2016-09-01

    Full Text Available 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.

  15. Pengaruh Penambahan Kitosan dalam Pembuatan Biodegradable Foam Berbahan Baku Pati

    Directory of Open Access Journals (Sweden)

    Nanik Hendrawati

    2017-05-01

    Full Text Available Biodegradable foam is an alternative packaging to replace the expanded polystyrene foam packaging currently in use.   Starch has been used to produce foam because of  its low cost, low density, low toxicity, and  biodegradability. Chitosan has been added to improve mechanical properties of product . The   effect of  variation on chitosan amount  and  starch types  was investigated in this study.  The amount of  chitosan  was varied as 0; 5; 10; 15; 20; 25; and  30 % w/w and starch types were used in this research were cassava, Corn and sago starch. Biodegradable  foam was produced by using baking process method, all of material (Starch, Chitosan solution,  Magnesium Stearate, Carrageenan, Glyserol, Protein Isolates  dan polyvinil alcohol (PVOH  were mixed with kitchen aid mixer. The mixture was poured  into mold and heated in an oven at 125 oC for 1 hour. Then, foam was tested for its mechanical properties, water absorption  and biodegradability and  morphology (SEM.  The results show that  foam made from sago starch had lower water absortion than those made from cassava and corn starch.   While, foam made from cassava starch  was more biodegradable than the other foam.  Biodegradable foam based sago starch and 30 % w/w of Chitosan adition  gave the  best performence in tensile stress that  is 20 Mpa

  16. Biodegradation of Polypropylene Nonwovens

    Science.gov (United States)

    Keene, Brandi Nechelle

    The primary aim of the current research is to document the biodegradation of polypropylene nonwovens and filament under composting environments. To accelerate the biodegradat ion, pre-treatments and additives were incorporated into polypropylene filaments and nonwovens. The initial phase (Chapter 2) of the project studied the biodegradation of untreated polypropylene with/without pro-oxidants in two types of composting systems. Normal composting, which involved incubation of samples in food waste, had little effect on the mechanical properties of additive-free spunbond nonwovens in to comparison prooxidant containing spunbond nonwovens which were affected significantly. Modified composting which includes the burial of samples with food and compressed air, the polypropylene spunbond nonwovens with/without pro-oxidants displayed an extreme loss in mechanical properties and cracking on the surface cracking. Because the untreated spunbond nonwovens did not completely decompose, the next phase of the project examined the pre-treatment of gamma-irradiation or thermal aging prior to composting. After exposure to gamma-irradiation and thermal aging, polypropylene is subjected to oxidative degradation in the presence of air and during storage after irradiat ion. Similar to photo-oxidation, the mechanism of gamma radiation and thermal oxidative degradation is fundamentally free radical in nature. In Chapter 3, the compostability of thermal aged spunbond polypropylene nonwovens with/without pro-oxidant additives. The FTIR spectrum confirmed oxidat ion of the polypropylene nonwovens with/without additives. Cracking on both the pro-oxidant and control spunbond nonwovens was showed by SEM imaging. Spunbond polypropylene nonwovens with/without pro-oxidants were also preirradiated by gamma rays followed by composting. Nonwovens with/without pro-oxidants were severely degraded by gamma-irradiation after up to 20 kGy exposure as explained in Chapter 4. Furthermore (Chapter 5), gamma

  17. Biodegradation of gallotannins and ellagitannins.

    Science.gov (United States)

    Li, Mingshu; Kai, Yao; Qiang, He; Dongying, Jia

    2006-01-01

    Nowadays, many researches have been made on gallotannin biodegradation and have gained great success in further utilization. Some of industrial applications of these findings are in the production of tannase, the biotransformation of tannic acid to gallic acid or pyrogallol and detannification of food and fodder. Although ellagitannins have the typical C-C bound which is more difficult to be degraded than gallotannins, concerted efforts are still in progress to improve ellagitannin degradation and utilization. Currently, more attention is mainly focused on intestinal microflora biodegradation of tannins especially ellagitannins which can contribute to the definition of their bioavailability for both human beings and ruminants. Also there have been endeavours to utilize the tannin-degrading activity of different fungi for ellagitannin-rich biomass, which will facilitate application of tannin-degrading enzymes in strategies for improving industrial and livestock production. Due to the complicated structures of complex tannins and condensed tannins, the biodegradation of them is much more difficult and there are fewer researches on them. Therefore, the researches on the mechanisms of gallotannin and ellagitannin biodegradation can result in the overall understanding to the biodegradation of complex tannins and condensed tannins. Biodegradation of tannins is in an incipient stage and further studies have to be carried out to exploit the potential of various tannins for largescale applications in food, fodder, medicine and tannery effluent treatment. ((c) 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim).

  18. Assessment of the environmental risk of long chain alcohols (LCOH)

    DEFF Research Database (Denmark)

    Belanger, Scott; Sanderson, Hans; Fisk, Peter

    2009-01-01

    rapidly in the environment (half-lives on the order of minutes); however, due to continuous use and distribution to wastewater treatment systems, partitioning properties, biodegradation of alcohol-based surfactants, and natural alcohol sources, LCOH are universally detected in wastewater effluents...... to alcohol-based surfactants and as alcohol per se in a wide variety of consumer product applications. Global production volume is approximately 1.58 million metric tonnes. The OECD HPV assessment covers linear to slightly branched LCOH ranging from 6 to 22 alkyl carbons (C). LCOH biodegrade exceptionally...... all uses of alcohol (i.e., the use of alcohol as a substance and as an intermediate for the manufacturing of alcohol-based surfactants). The 90th percentile effluent discharge concentration of 1.979 μg/L (C12-C15) was determined for wastewater treatment plants in 7 countries. Chronic aquatic toxicity...

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

    Science.gov (United States)

    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 ...

  20. Long term studies on the anaerobic biodegradability of MTBE and other gasoline ethers

    DEFF Research Database (Denmark)

    Waul, Christopher Kevin; Arvin, Erik; Schmidt, Jens Ejbye

    2009-01-01

    to investigate the anaerobic biodegradability of MTBE and other gasoline ethers. Inoculums collected from various environments were used, along with different electron acceptors. Only one set of the batch experiments showed a 30-60% conversion of MTBE to tert-butyl alcohol under Fe(III)-reducing conditions...

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

    Science.gov (United States)

    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…

  2. Evaluation of biodegradable plastics for rubber seedling applications

    Science.gov (United States)

    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.

  3. Biodegradation of kerosene by Aspergillus ochraceus NCIM-1146.

    Science.gov (United States)

    Saratale, Ganesh; Kalme, Satish; Bhosale, Sanjyot; Govindwar, Sanjay

    2007-10-01

    The filamentous fungus Aspergillus ochraceus NCIM-1146 was found to degrade kerosene, when previously grown mycelium (96 h) was incubated in the broth containing kerosene. Higher levels of NADPH-DCIP reductase, aminopyrine N-demethylase and kerosene biodegradation activities were found to be present after the growth in potato dextrose broth for 96 h, when compared with the activities at different time intervals during the growth phase. NADPH was the preferred cofactor for enzyme activity, which was inhibited by CO, indicating cytochrome P450 mediated reactions. A significant increase in all the enzyme activities was observed when mycelium incubated for 18 h in mineral salts medium, containing cholesterol, camphor, naphthalene, 1,2-dimethoxybenzene, phenobarbital, n-hexane, kerosene or saffola oil as inducers. Acetaldehyde produced by alcohol dehydrogenase could be used as an indicator for the kerosene biodegradation.

  4. Progress of biodegradable metals

    Directory of Open Access Journals (Sweden)

    Huafang Li

    2014-10-01

    Full Text Available Biodegradable metals (BMs are metals and alloys expected to corrode gradually in vivo, with an appropriate host response elicited by released corrosion products, then dissolve completely upon fulfilling the mission to assist with tissue healing with no implant residues. In the present review article, three classes of BMs have been systematically reviewed, including Mg-based, Fe-based and Zn-based BMs. Among the three BM systems, Mg-based BMs, which now have several systems reported the successful of clinical trial results, are considered the vanguards and main force. Fe-based BMs, with pure iron and Fe–Mn based alloys as the most promising, are still on the animal test stage. Zn-based BMs, supposed to have the degradation rate between the fast Mg-based BMs and the slow Fe-based BMs, are a rising star with only several reports and need much further research. The future research and development direction for the BMs are proposed, based on the clinical requirements on controllable degradation rate, prolonged mechanical stability and excellent biocompatibility, by optimization of alloy composition design, regulation on microstructure and mechanical properties, and following surface modification.

  5. Treatment of biodegradable material

    Energy Technology Data Exchange (ETDEWEB)

    Pannell, S.D.; Greenshields, R.N.

    1981-05-13

    Biodegradable effluents, e.g. containing carbohydrates and/or proteins, were treated by passing up a tower fermenter tapered at the top and with an aspect ratio of greater than or equal to 3:1. A flocculant microorganism aerobically digested the effluent in the tower and the mixture of treated medium, gas, and surplus microorganism was discharged through an inverted-U-shaped outlet at the top. After separation of the biomass, which could be used as an animal feed, the purified effluent could be discharged. A milk-processing effluent (2.5 g solids/l, of which 65% was sucrose and 35% milk solids) was treated in a fermentation tower (aspect ratio 10:1). Aspergillus niger in the tower readily digested sucrose and at least some lactose as air and NH/sub 4/NO/sub 3/ were added. At least 90% of the casein was trapped by the microorganisms and discharged with them from the tower. The microrganisms were separated with a vibrating sieve giving a final discharged liquid containing 0.2 g solids/l.

  6. Alcohol Alert: Genetics of Alcoholism

    Science.gov (United States)

    ... and Reports » Alcohol Alert » Alcohol Alert Number 84 Alcohol Alert Number 84 Print Version The Genetics of ... immune defense system. Genes Encoding Enzymes Involved in Alcohol Breakdown Some of the first genes linked to ...

  7. Biodegradable Peptide-Silica Nanodonuts.

    Science.gov (United States)

    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. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. ANAEROBIC BIODEGRADATION OF A BIODEGRADABLE MATERIAL UNDER ANAEROBIC - THERMOPHILIC DIGESTION

    Directory of Open Access Journals (Sweden)

    RICARDO CAMACHO-MUÑOZ

    2014-12-01

    Full Text Available This paper dertermined the anaerobic biodegradation of a polymer obtained by extrusion process of native cassava starch, polylactic acid and polycaprolactone. Initially a thermophilic - methanogenic inoculum was prepared from urban solid waste. The gas final methane concentration and medium’s pH reached values of 59,6% and 7,89 respectively. The assay assembly was carried out according ASTM D5511 standard. The biodegradation percent of used materials after 15 day of digestion were: 77,49%, 61,27%, 0,31% for cellulose, sample and polyethylene respectively. Due cellulose showed biodegradation levels higher than 70% it’s deduced that the inoculum conditions were appropriate. A biodegradation level of 61,27%, 59,35% of methane concentration in sample’s evolved gas and a medium’s finale pH of 7,71 in sample’s vessels, reveal the extruded polymer´s capacity to be anaerobically degraded under thermophilic- high solid concentration conditions.

  9. Biodegradable congress 2012; Bioschmierstoff-Kongress 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Within the Guelzower expert discussions at 5th and 6th June, 2012 in Oberhausen (Federal Republic of Germany) the following lectures were held: (1) Promotion of biodegradable lubricants by means of research and development as well as public relations (Steffen Daebeler); (2) Biodegradable lubricants - An overview of the advantages and disadvantages of the engaged product groups (Hubertus Murrenhoff); (3) Standardization of biodegradable lubricants - CEN/DIN standard committees - state of the art (Rolf Luther); (4) Market research for the utilization of biodegradable lubricants and means of proof of sustainability (Norbert Schmitz); (5) Fields of application for high performance lubricants and requirements upon the products (Gunther Kraft); (6) Investigations of biodegradable lubricants in rolling bearings and gears (Christoph Hentschke); (7) Biodegradable lubricants in central lubrication systems Development of gears and bearings of offshore wind power installations (Reiner Wagner); (8) Investigations towards environmental compatibility of biodegradable lubricants used in offshore wind power installations (Tolf Schneider); (9) Development of glycerine based lubricants for the industrial metalworking (Harald Draeger); (10) Investigations and utilization of biodegradable oils as electroinsulation oils in transformers (Stefan Tenbohlen); (11) Operational behaviour of lubricant oils in vegetable oil operation and Biodiesel operation (Horst Hamdorf); (12) Lubrication effect of lubricating oil of the third generation (Stefan Heitzig); (13) Actual market development from the view of a producer of biodegradable lubricants (Frank Lewen); (14) Utilization of biodegradable lubricants in forestry harvesters (Guenther Weise); (15) New biodegradable lubricants based on high oleic sunflower oil (Otto Botz); (16) Integrated fluid concept - optimized technology and service package for users of biodegradable lubricants (Juergen Baer); (17) Utilization of a bio oil sensor to control

  10. Preparation of biodegradable gelatin/PVA porous scaffolds for skin regeneration.

    Science.gov (United States)

    Mahnama, Hossein; Dadbin, Susan; Frounchi, Masoud; Rajabi, Sareh

    2017-08-01

    Porous scaffolds composed of gelatin/poly (vinyl alcohol), (Gel/PVA), were prepared using combination of freeze gelation and freeze drying methods. The effect of polymer concentration, gelatin/PVA ratio, and glutaraldehyde/gelatin ratio (GA/Gel) was investigated on morphology of pores, swelling ratio, biodegradation, and skin cell culture. At optimum preparation conditions the scaffolds had uniform pore size distributions showing high swelling ratio of 23.6. The scaffolds were of biodegradable nature and almost degraded in 28 days. Human dermal fibroblast cells (HDF) were cultured on the scaffolds and MTS assay was conducted to evaluate the influence of PVA on growth and proliferation of the cells.

  11. Biodegradable polymeric prodrugs of naltrexone

    NARCIS (Netherlands)

    Bennet, D.B.; Li, X.; Adams, N.W.; Kim, S.W.; Hoes, C.J.T.; Hoes, C.J.T.; Feijen, Jan

    1991-01-01

    The development of a biodegradable polymeric drug delivery system for the narcotic antagonist naltrexone may improve patient compliance in the treatment of opiate addiction. Random copolymers consisting of the ¿-amino acids N5-(3-hydroxypropyl--glutamine and -leucine were synthesized with equimolar

  12. Biodegradable poly(lactic acid)

    Indian Academy of Sciences (India)

    The fabrication of biodegradable poly(lactic acid) (PLA) microspheres containing total alkaloids of Caulis sinomenii was investigated. The formation, diameter, morphology and properties of the microspheres were characterized using Fourier transform infrared spectroscopy (FT–IR), laser particle size analyser and scanning ...

  13. Alcohol Abuse

    Science.gov (United States)

    ... Drinking to Excess U.S. National Library of Medicine, Alcoholism and Alcohol Abuse Last Updated: June 27, 2017 This article was contributed by: familydoctor.org editorial staff Categories: Family Health, Kids and Teens, Men, Seniors, WomenTags: alcohol, alcohol abuse, alcohol addiction ...

  14. Additional Equipment for Soil Biodegradation

    Science.gov (United States)

    Vondráčková, Terezie; Kraus, Michal; Šál, Jiří

    2017-12-01

    Intensification of industrial production, increasing citizens’ living standards, expanding the consumer assortment mean in the production - consumption cycle a constantly increasing occurrence of waste material, which by its very nature must be considered as a source of useful raw materials in all branches of human activity. In addition to strict legislative requirements, a number of circumstances characterize waste management. It is mainly extensive transport associated with the handling and storage of large volumes of substances with a large assortment of materials (substances of all possible physical and chemical properties) and high demands on reliability and time coordination of follow-up processes. Considerable differences in transport distances, a large number of sources, processors and customers, and not least seasonal fluctuations in waste and strong price pressures cannot be overlooked. This highlights the importance of logistics in waste management. Soils that are contaminated with oil and petroleum products are hazardous industrial waste. Methods of industrial waste disposal are landfilling, biological processes, thermal processes and physical and chemical methods. The paper focuses on the possibilities of degradation of oil pollution, in particular biodegradation by bacteria, which is relatively low-cost among technologies. It is necessary to win the fight with time so that no ground water is contaminated. We have developed two additional devices to help reduce oil accident of smaller ranges. In the case of such an oil accident, it is necessary to carry out the permeability test of contaminated soil in time and, on this basis, to choose the technology appropriate to the accident - either in-sit biodegradation - at the site of the accident, or on-sit - to remove the soil and biodegrade it on the designated deposits. A special injection drill was developed for in-sit biodegradation, tossing and aeration equipment of the extracted soil was developed for

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

    Science.gov (United States)

    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.

  16. Biodegradation of blend films PVA/PVC, PVA/PCL in soil and soil with landfill leachate

    Directory of Open Access Journals (Sweden)

    Adriana de Campos

    2011-12-01

    Full Text Available This study investigated the biodegradation of blends films of poly(vinyl alcohol/poly(vinyl chloride (PVA/PVC and poly(vinyl alcohol/poly(caprolactone (PVA/PCL blends films prepared with dimethylformamide under a variety of conditions by respirometry, spectrophotometry (FTIR, scanning electron microscopy (SEM, and contact angle. The films were buried in the garden soil and in the soil mixed with the landfill leachate for 120 days at 28ºC. Significant levels of biodegradation were achieved in fairly short incubation times in the soil. The results indicated that PVA was the most biodegradable film in the soil and in the soil with the leachate.

  17. Radiation effects on biodegradable polyesters

    International Nuclear Information System (INIS)

    Hiroshi Mitomo; Darmawan Darwis; Fumio Yoshii; Keizo Makuuchi

    1999-01-01

    Poly(3-hydroxybutyrate) [P(3HB)] and its copolymer poly(3-hydroxybutyrate-co-3hydroxyvalerate) [P(3HB-co-3HV)] are microbial biodegradable polyesters produced by many types of bacteria. Poly(butylene succinate) (PBS) and poly(E-caprolactone) (PCL) are also biodegradable synthetic polyesters which have been commercialized. These thermoplastics are expected for wide usage in environmental protection and blocompatible applications. Radiation grafting of hydrophilic monomers onto many polymers, e.g., polyethylene and polypropylene has been studied mainly for biomedical applications. In the present study, radiation-induced graft polymerization of vinyl monomers onto PHB and P(3HB-co-3HV) was carried out and improvement of their properties was studied. Changes in the properties and biodegradability were compared with the degree of grafting. Radiation-induced crosslinking of PBS and PCL which relatively show thermal and irradiation stability was also carried out to improve their thermal stability or processability. Irradiation to PBS and PCL mainly resulted in crosslinking and characterization of these crosslinked polyesters was investigated

  18. Black Alcoholism.

    Science.gov (United States)

    Watts, Thomas D.; Wright, Roosevelt

    1988-01-01

    Examines some aspects of the problem of alcoholism among Blacks, asserting that Black alcoholism can best be considered in an ecological, environmental, sociocultural, and public health context. Notes need for further research on alcoholism among Blacks and for action to reduce the problem of Black alcoholism. (NB)

  19. Alcohol withdrawal

    Science.gov (United States)

    ... so they can monitor you for symptoms of alcohol withdrawal. Prevention Reduce or avoid alcohol. If you have a drinking problem, you should ... team. 02-05-18: Editorial update. Alcoholism and Alcohol Abuse Read more ... HealthCare Commission (www.urac.org). URAC's accreditation program is an independent audit to verify that A. ...

  20. Biodegradable polymers in Quebec; Les polymeres biodegradables au Quebec

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    Poly-hydroxy-alkanoates (PHA) are natural polymers made from renewable resources and are easily recyclable, hydrolyzable and biodegradable. Thanks to genetic technologies, PHA can be synthesized from plants or bacteria and can be used in various domains ranging from the manufacturing of packing materials to medical applications. Moreover, their properties make them good substitutes of equivalent petroleum-derived compounds. This report makes a status of Quebec's research work on PHAs and presents the three main research centers in which such studies are carried out: the biotechnology research institute, the Mc Gill university and the Polytechnique school of Montreal. (J.S.)

  1. Biodegradability and biodegradation pathways of endosulfan and endosulfan sulfate.

    Science.gov (United States)

    Kataoka, Ryota; Takagi, Kazuhiro

    2013-04-01

    Endosulfan and endosulfan sulfate are persistent organic pollutants that cause serious environmental problems. Although these compounds are already prohibited in many countries, residues can be detected in soils with a history of endosulfan application. Endosulfan is transformed in the environment into endosulfan sulfate, which is a toxic and persistent metabolite. However, some microorganisms can degrade endosulfan without producing endosulfan sulfate, and some can degrade endosulfan sulfate. Therefore, biodegradation has the potential to clean up soil contaminated with endosulfan. In this review, we provide an overview of aerobic endosulfan degradation by bacteria and fungi, and a summary of recent advances and prospects in this research field.

  2. Alcohol Calorie Calculator

    Science.gov (United States)

    ... 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 ...

  3. Biodegradation kinetics at low concentrations (

    DEFF Research Database (Denmark)

    Toräng, Lars; Albrechtsen, Hans-Jørgen; Nyholm, Niels

    2000-01-01

    Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 mu g/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization...... in the order of 200 days. Higher concentrations of 2,4-D resulted in a grossly overestimate of the actual degradation rate for concentrations characteristic for Danish found in groundwater....

  4. Evaluation of biodegradation and biocompatibility of collagen ...

    Indian Academy of Sciences (India)

    ing material in tissue engineering applications owing to its excellent biocompatibility and biodegradability [2]. How- ever, its fast biodegradation and low mechanical strength are the foremost issues that limit the further uses of this material. Another extensively studied material is chitosan, a linear polysaccharide derived by ...

  5. Enhancing the biodegradation process of cassava ( Manihot ...

    African Journals Online (AJOL)

    Cassava (Manihot esculenta Crantz) peels have been implicated in serious environmental pollution. This study was aimed at investigating the effect of N.P.K (15:15:15) and microbial inoculants on the biodegradation process of cassava peels. Fresh cassava peels were subjected to biodegradation process for twenty weeks.

  6. Biodegradation of phenol by Pseudomonas pictorum on ...

    African Journals Online (AJOL)

    Biodegradation of phenol using Pseudomonas pictorum (ATCC 23328) a potential biodegradant of phenol was investigated under different operating conditions. Chitin was chosen as a support material and then partially characterized physically and chemically. The pH of the solution was varied over a range of 7 – 9.

  7. Biodegradation of dodecylbenzene solfonate sodium by ...

    African Journals Online (AJOL)

    STORAGESEVER

    2010-01-04

    Jan 4, 2010 ... Key words: Branched anionic surfactants, biofilm, biodegradation, silanization. ... polymers, pesticides, oil recovery, textiles and paper ... surfactants are not degraded by microorganisms in the environment. Because of its low biodegradation ability and toxic effects on environment, BAS was forbidden in.

  8. Biodegradation of phenol with immobilized Pseuodomonas putida ...

    African Journals Online (AJOL)

    Biodegradation of phenol with immobilized Pseuodomonas putida activated carbon packed bio-filter tower. ... Comparative study on adsorption and simultaneous adsorption and biodegradation (SAB) of phenol using Pseuodomonas putida (MTCC 1194) in a biofilter tower packed with fresh granular activated carbon (GAC) ...

  9. Nylon biodegradation by lignin-degrading fungi.

    Science.gov (United States)

    Deguchi, T; Kakezawa, M; Nishida, T

    1997-01-01

    The biodegradation of nylon by lignin-degrading fungi was investigated. The fungus IZU-154 significantly degraded nylon-66 membrane under ligninolytic conditions. Nuclear magnetic resonance analysis showed that four end groups, CHO, NHCHO, CH3, and CONH2, were formed in the biodegraded nylon-66 membranes, suggesting that nylon-66 was degraded oxidatively. PMID:8979361

  10. Nylon biodegradation by lignin-degrading fungi.

    OpenAIRE

    Deguchi, T; Kakezawa, M; Nishida, T

    1997-01-01

    The biodegradation of nylon by lignin-degrading fungi was investigated. The fungus IZU-154 significantly degraded nylon-66 membrane under ligninolytic conditions. Nuclear magnetic resonance analysis showed that four end groups, CHO, NHCHO, CH3, and CONH2, were formed in the biodegraded nylon-66 membranes, suggesting that nylon-66 was degraded oxidatively.

  11. Biodegradability of electrostatic photocopier toners | Odokuma ...

    African Journals Online (AJOL)

    Biodegradation was monitored over a 28-day period using changes total organic carbon (TOC), Dissolved organic carbon (DOC) ratio of DOC to TOC (Primary biodegradation) and Biochemical Oxygen Demand (BOD) measurements. At day 0 the BOD for Fresh Sharp, Reused Sharp, Fresh Minolta and Reused Minolta ...

  12. Formulation and Characterization of Biodegradable Medicated ...

    African Journals Online (AJOL)

    (TPA), biodegradation, in vitro drug release using a modified chewing apparatus, and sensory properties. Result: Formulations code MCG-5 and MCG-9 which incorporated glyceryl triacetate and castor oil as plasticizers, respectively, showed a biodegradation score of 2 and 1, respectively, indicating significant.

  13. Simultaneous adsorption and biodegradation of synthetic melanoidin

    African Journals Online (AJOL)

    Being an antioxidant, melanoidin removal through purely biodegradation has been inadequate. Consequently, in the current study, simultaneous adsorption and biodegradation (SAB) was employed in a stirred tank system to remove melanoidin from synthetic wastewater. Mixed microbial consortium was immobilized onto ...

  14. Biodegradable polymers for electrospinning: towards biomedical applications.

    Science.gov (United States)

    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. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Biodegradation of bioplastics in natural environments.

    Science.gov (United States)

    Emadian, S Mehdi; Onay, Turgut T; Demirel, Burak

    2017-01-01

    The extensive production of conventional plastics and their use in different commercial applications poses a significant threat to both the fossil fuels sources and the environment. Alternatives called bioplastics evolved during development of renewable resources. Utilizing renewable resources like agricultural wastes (instead of petroleum sources) and their biodegradability in different environments enabled these polymers to be more easily acceptable than the conventional plastics. The biodegradability of bioplastics is highly affected by their physical and chemical structure. On the other hand, the environment in which they are located, plays a crucial role in their biodegradation. This review highlights the recent findings attributed to the biodegradation of bioplastics in various environments, environmental conditions, degree of biodegradation, including the identified bioplastic-degrading microorganisms from different microbial communities. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Alcoholic Hepatitis

    Science.gov (United States)

    ... avoid all alcohol. Protect yourself from hepatitis C. Hepatitis C is an infectious liver disease caused by a virus. Untreated, it can lead to cirrhosis. If you have hepatitis C and drink alcohol, you're far more likely ...

  17. Alcohol Intolerance

    Science.gov (United States)

    ... an alcoholic beverage — such as chemicals, grains or preservatives. Combining alcohol with certain medications also can cause reactions. In rare instances, an unpleasant reaction to alcohol can be a sign of a serious underlying health problem that requires diagnosis and treatment. Symptoms Signs ...

  18. Alcohol misuse

    OpenAIRE

    Coulton, Simon

    2011-01-01

    Alcohol use is a leading cause of mortality and morbidity internationally, and is ranked by the WHO as one of the top 5 risk factors for disease burden. Without treatment, approximately 16% of hazardous or harmful alcohol users will progress to more dependent patterns of alcohol consumption.

  19. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lihui [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Zhang, Yongming, E-mail: zhym@shnu.edu.cn [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Bai, Qi; Yan, Ning; Xu, Hua [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Rittmann, Bruce E. [Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, AZ 85287-5701 (United States)

    2015-04-28

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.

  20. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    International Nuclear Information System (INIS)

    Yang, Lihui; Zhang, Yongming; Bai, Qi; Yan, Ning; Xu, Hua; Rittmann, Bruce E.

    2015-01-01

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA

  1. Primary biodegradation and mineralization of hair shampoos in ...

    African Journals Online (AJOL)

    Two methods, the methylene blue active stain (MBAS) river die away method for monitoring primary biodegradation of surfactants and the ultimate biodegradability method for monitoring mineralization of the total biodegradable organic component in a compound were employed to determine the biodegradability of three ...

  2. Microbial Enzymatic Degradation of Biodegradable Plastics.

    Science.gov (United States)

    Roohi; Bano, Kulsoom; Kuddus, Mohammed; Zaheer, Mohammed R; Zia, Qamar; Khan, Mohammed F; Ashraf, Ghulam Md; Gupta, Anamika; Aliev, Gjumrakch

    2017-01-01

    The renewable feedstock derived biodegradable plastics are important in various industries such as packaging, agricultural, paper coating, garbage bags and biomedical implants. The increasing water and waste pollution due to the available decomposition methods of plastic degradation have led to the emergence of biodegradable plastics and biological degradation with microbial (bacteria and fungi) extracellular enzymes. The microbes utilize biodegradable polymers as the substrate under starvation and in unavailability of microbial nutrients. Microbial enzymatic degradation is suitable from bioremediation point of view as no waste accumulation occurs. It is important to understand the microbial interaction and mechanism involved in the enzymatic degradation of biodegradable plastics under the influence of several environmental factors such as applied pH, thermo-stability, substrate molecular weight and/or complexity. To study the surface erosion of polymer film is another approach for hydrolytic degradation characteristion. The degradation of biopolymer is associated with the production of low molecular weight monomer and generation of carbon dioxide, methane and water molecule. This review reported the degradation study of various existing biodegradable plastics along with the potent degrading microbes (bacteria and fungi). Patents available on plastic biodegradation with biotechnological significance is also summarized in this paper. This paper assesses that new disposal technique should be adopted for the degradation of polymers and further research is required for the economical production of biodegradable plastics along with their enzymatic degradation. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. Alcohols toxicology

    Energy Technology Data Exchange (ETDEWEB)

    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

  4. Biodegradable and compostable alternatives to conventional plastics.

    Science.gov (United States)

    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. Biodegradable and compostable alternatives to conventional plastics

    Science.gov (United States)

    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

  6. Biodegradable Metals From Concept to Applications

    CERN Document Server

    Hermawan, Hendra

    2012-01-01

    This book in the emerging research field of biomaterials covers biodegradable metals for biomedical applications. The book contains two main parts where each of them consists of three chapters. The first part introduces the readers to the field of metallic biomaterials, exposes the state of the art of biodegradable metals, and reveals its application for cardiovascular implants. It includes some fundamental aspects to give basic understanding on metals for further review on the degradable ones is covered in chapter one. The second chapter introduces the concept of biodegradable metals, it's st

  7. New perspectives in plastic biodegradation.

    Science.gov (United States)

    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. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Engineered biosynthesis of biodegradable polymers.

    Science.gov (United States)

    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.

  9. Biodegradable polyesters from renewable resources.

    Science.gov (United States)

    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.

  10. Cultivation of Aquincola tertiaricarbonis L108 on the fuel oxygenate intermediate tert-butyl alcohol induces aerobic anoxygenic photosynthesis at extremely low feeding rates.

    Science.gov (United States)

    Rohwerder, Thore; Müller, Roland H; Weichler, M Teresa; Schuster, Judith; Hübschmann, Thomas; Müller, Susann; Harms, Hauke

    2013-10-01

    Aerobic anoxygenic photosynthesis (AAP) is found in an increasing number of proteobacterial strains thriving in ecosystems ranging from extremely oligotrophic to eutrophic. Here, we have investigated whether the fuel oxygenate-degrading betaproteobacterium Aquincola tertiaricarbonis L108 can use AAP to compensate kinetic limitations at low heterotrophic substrate fluxes. In a fermenter experiment with complete biomass retention and also during chemostat cultivation, strain L108 was challenged with extremely low substrate feeding rates of tert-butyl alcohol (TBA), an intermediate of methyl tert-butyl ether (MTBE). Interestingly, formation of photosynthetic pigments, identified as bacteriochlorophyll a and spirilloxanthin, was only induced in growing cells at TBA feeding rates less than or equal to maintenance requirements observed under energy excess conditions. Growth continued at rates between 0.001 and 0.002 h(-1) even when the TBA feed was decreased to values close to 30 % of this maintenance rate. Partial sequencing of genomic DNA of strain L108 revealed a bacteriochlorophyll synthesis gene cluster (bchFNBHL) and photosynthesis regulator genes (ppsR and ppaA) typically found in AAP and other photosynthetic proteobacteria. The usage of light as auxiliary energy source enabling evolution of efficient degradation pathways for kinetically limited heterotrophic substrates and for lowering the threshold substrate concentration Smin at which growth becomes zero is discussed.

  11. Alcohol and pregnancy

    Science.gov (United States)

    Drinking alcohol during pregnancy; Fetal alcohol syndrome - pregnancy; FAS - fetal alcohol syndrome ... When a pregnant woman drinks alcohol, the alcohol travels through her blood and into the baby's blood, tissues, and organs. Alcohol breaks down much more slowly in ...

  12. Older Adults and Alcohol

    Science.gov (United States)

    Skip to main content National Institute on Alcohol Abuse and Alcoholism (NIAAA) Main Menu Search Search form Search Alcohol & Your Health Overview of Alcohol Consumption Alcohol's Effects on the Body Alcohol ...

  13. Aerobic Biodegradation of Fuel Oxygenates

    Science.gov (United States)

    2007-06-01

    reduction of tert-butyl hydroperoxide (Clark, 2002). At normal room temperature it is a colorless clear crystalline solid with a camphor like odor...U.S. Department of Labor, Occupational Safety and Health Administration. (1996). Occupational safety and health guideline for tert-butyl alcohol

  14. Acceleration of biodegradation by ultraviolet femtosecond laser irradiation to biodegradable polymer

    Science.gov (United States)

    Shibata, Akimichi; Yada, Shuhei; Kondo, Naonari; Terakawa, Mitsuhiro

    2017-02-01

    Biodegradability is a key property of biodegradable polymers for tissue scaffold applications. Among the methods to control biodegradability, laser processing is a simple technique, which enables the alteration of biodegradability even after molding. Since ultrafast laser processing realizes precise processing of biodegradable polymer with less heat affected zone, ultrafast laser processing has the potential to fabricate tissue scaffolds and to control its biodegradability. In this study, we investigate the effect of femtosecond laser wavelength on the biodegradability of PLGA. We evaluated the biodegradability of PLGA irradiated with femtosecond laser pulses at the wavelength of 800, 400, 266 nm by the measurement of the change in mass of PLGA during water immersion. The results of degradation tests indicate that PLGA irradiated with the shorter wavelength show faster water absorption as well as rapid mass decrease. Since the results of X-ray photoelectron spectroscopy analysis indicate that the chemical bonds of PLGA irradiated with the shorter wavelength are dissociated more significantly, the acceleration of the biodegradation could be attributable to the decrease in molecular weight by chemical bond breaking.

  15. Deciding to quit drinking alcohol

    Science.gov (United States)

    ... Alcoholism. Alcohol and health. www.niaaa.nih.gov/alcohol-health . Accessed March 18, 2016. National Institute on Alcohol ... Alcoholism. Alcohol use disorder. www.niaaa.nih.gov/alcohol-health/overview-alcohol-consumption/alcohol-use-disorders . Accessed March ...

  16. Physical and Degradable Properties of Mulching Films Prepared from Natural Fibers and Biodegradable Polymers

    Directory of Open Access Journals (Sweden)

    Zhijian Tan

    2016-05-01

    Full Text Available The use of plastic film in agriculture has the serious drawback of producing vast quantities of waste. In this work, films were prepared from natural fibers and biodegradable polymers as potential substitutes for the conventional non-biodegradable plastic film used as mulching material in agricultural production. The physical properties (e.g., mechanical properties, heat preservation, water permeability, and photopermeability and degradation characteristics (evaluated by micro-organic culture testing and soil burial testing of the films were studied in both laboratory and field tests. The experimental results indicated that these fiber/polymer films exhibited favorable physical properties that were sufficient for use in mulching film applications. Moreover, the degradation degree of the three tested films decreased in the following order: fiber/starch (ST film > fiber/poly(vinyl alcohol (PVA film > fiber/polyacrylate (PA film. The fiber/starch and fiber/PVA films were made from completely biodegradable materials and demonstrated the potential to substitute non-biodegradable films.

  17. Biodegradation of VX/Water Hydrolysate

    National Research Council Canada - National Science Library

    DeFrank, Joseph

    1997-01-01

    ...-(diisopropylaminoethyl) methyl phosphonothioate was neutralization followed by biodegradation. The treatment of VX with an equimolar amount of water results in the slow, but complete hydrolysis of the phosphorus-sulfur bond...

  18. Biodegradable lubricants - ''the solution for future?''

    International Nuclear Information System (INIS)

    Jahan, A.

    1997-01-01

    The environmental impact of lubricants use concern the direct effects from spills but also the indirect effects such as their lifetime and the emissions from thermal engines. The biodegradable performances and the toxicity are the environmental criteria that must be taken into account in the development and application of lubricants together with their technical performances. This paper recalls first the definition of biodegradable properties of hydrocarbons and the standardized tests, in particular the CEC and AFNOR tests. Then, the biodegradable performances of basic oils (mineral, vegetal, synthetic esters, synthetic hydrocarbons etc..), finite lubricants (hydraulic fluids..) and engine oils is analyzed according to these tests. Finally, the definition of future standards would take into account all the environmental characteristics of the lubricant: biodegradable performances, energy balance (CO 2 , NOx and Hx emissions and fuel savings), eco-toxicity and technical performances (wearing and cleanliness). (J.S.)

  19. Biodegradability and treatability of caprolactam waste

    Energy Technology Data Exchange (ETDEWEB)

    Patel, M.D.; Patel, D.R.

    1977-01-01

    Studies were conducted on the biodegradability and treatment of wastewaters from a plant manufacturing caprolactam. Two-stage biological treatment, with preliminary aeration followed by an oxidation channel, gave an effluent of the desired quality.

  20. MOLECULAR BASIS OF BIODEGRADATION OF CHLOROAROMATIC COMPOUNDS

    Science.gov (United States)

    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...

  1. Formulation and Characterization of Biodegradable Medicated ...

    African Journals Online (AJOL)

    PEG)-600, tributyl citrate, PEG-200, PEG-300, PEG-400, PEG-4000, triethyl citrate and castor oil. The gum formulations were characterized for the following parameters: texture profile analysis (TPA), biodegradation, in vitro drug release using a ...

  2. Radiation processing of indigenous natural polymers. Properties of radiation modified blends from sago-starch for biodegradable composite

    International Nuclear Information System (INIS)

    Ghazali, Z.; Dahlan, K.Z.; Wongsuban, B.; Idris, S.; Muhammad, K.

    2001-01-01

    Research and development on biodegradable polymer blends and composites have gained wider interest to offer alternative eco-friendly products. Natural polysaccharide such as sago-starch offers the most promising raw material for the production of biodegradable composites. The potential of sago, which is so abundant in Malaysia, to produce blends for subsequent applications in composite material, was evaluated and explored. Blends with various formulations of sago starch and polyvinyl alcohol (PVA), and polyvinyl pyrrolidone (PVP) polymers were prepared and subjected to radiation modification using electron beam irradiation. The effect of irradiation on the sago and its blends was evaluated and their properties were characterized. The potential of producing composite from sago blends was explored. Foams from these blends were produced using microwave oven while films were produced through casting method. The properties such as mechanical, water absorption, expansion ratio, and biodegradability were characterized and reported in this paper. (author)

  3. Craving Alcohol.

    OpenAIRE

    Murphy, James Peter

    2014-01-01

    Individuals involved in the treatment of alcoholism for decades have argued that men and women crave alcohol essentially because they enjoy the effect it offers. This effect is so mysterious that, while adults will confess that these cravings are potential dangerous to their health and well being, during consumption their reasoning and belief of these facts will alternate between the true and the false. In essence these individuals alcohol cravings life actually seems to them the only normal ...

  4. Biodegradation of acrylic based resins: A review.

    Science.gov (United States)

    Bettencourt, Ana F; Neves, Cristina B; de Almeida, Marise S; Pinheiro, Lídia M; Oliveira, Sofia Arantes e; Lopes, Luís P; Castro, Matilde F

    2010-05-01

    The development of different types of materials with application in dentistry is an area of intense growth and research, due to its importance in oral health. Among the different materials there are the acrylic based resins that have been extensively used either in restorations or in dentures. The objective of this manuscript was to review the acrylic based resins biodegradation phenomena. Specific attention was given to the causes and consequences of materials degradation under the oral environment. Information from scientific full papers, reviews or abstracts published from 1963 to date were included in the review. Published material was searched in dental literature using general and specialist databases, like the PubMED database. Published studies regarding the description of biodegradation mechanisms, in vitro and in vivo release experiments and cell based studies conducted on acrylic based resins or their components were evaluated. Studies related to the effect of biodegradation on the physical and mechanical properties of the materials were also analyzed. Different factors such as saliva characteristics, chewing or thermal and chemical dietary changes may be responsible for the biodegradation of acrylic based resins. Release of potential toxic compounds from the material and change on their physical and mechanical properties are the major consequences of biodegradation. Increasing concern arises from potential toxic effects of biodegradation products under clinical application thus justifying an intensive research in this area. 2010 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  5. Biodegradability and biodegradation rate of poly(caprolactone)-starch blend and poly(butylene succinate) biodegradable polymer under aerobic and anaerobic environment.

    Science.gov (United States)

    Cho, H S; Moon, H S; Kim, M; Nam, K; Kim, J Y

    2011-03-01

    The biodegradability and the biodegradation rate of two kinds biodegradable polymers; poly(caprolactone) (PCL)-starch blend and poly(butylene succinate) (PBS), were investigated under both aerobic and anaerobic conditions. PCL-starch blend was easily degraded, with 88% biodegradability in 44 days under aerobic conditions, and showed a biodegradation rate of 0.07 day(-1), whereas the biodegradability of PBS was only 31% in 80 days under the same conditions, with a biodegradation rate of 0.01 day(-1). Anaerobic bacteria degraded well PCL-starch blend (i.e., 83% biodegradability for 139 days); however, its biodegradation rate was relatively slow (6.1 mL CH(4)/g-VS day) compared to that of cellulose (13.5 mL CH(4)/g-VS day), which was used as a reference material. The PBS was barely degraded under anaerobic conditions, with only 2% biodegradability in 100 days. These results were consistent with the visual changes and FE-SEM images of the two biodegradable polymers after the landfill burial test, showing that only PCL-starch blend had various sized pinholes on the surface due to attack by microorganisms. This result may be use in deciding suitable final disposal approaches of different types of biodegradable polymers in the future. Copyright © 2010 Elsevier Ltd. All rights reserved.

  6. Use Of Biodegradation Ratios In Monitoring Trend Of Biostimulated Biodegradation In Crude Oil Polluted Soils

    Directory of Open Access Journals (Sweden)

    Okorondu

    2017-03-01

    Full Text Available This study deals with biodegradation experiment on soil contaminated with crude oil. The soil sample sets A BC D E F G were amended with inorganic fertilizer to enhance microbial growth and hydrocarbon degradation moisture content of some of the sets were as well varied. Biodegradation ratios nC17Pr nC18Ph and nC17nC18PrPh were used to monitor biodegradation of soil sets A BC D E F G for a period of 180. The soil samples were each contaminated with the same amount of crude oil and exposed to specific substrate treatment regarding the amount of nutrients and water content over the same period of time. The trend in biodegradation of the different soil sample sets shows that biodegradation ratio nC17nC18PrPh was more reflective of and explains the biodegradation trend in all the sample sets throughout the period of the experiment hence a better parameter ratio for monitoring trend of biostimulated biodegradation. The order of preference of the biodegradation ratios is expressed as nC18Ph nC17Pr nC17nC18 PrPh. This can be a relevant support tool when designing bioremediation plan on field.

  7. Influence of Mechanical Properties of Aerial Shells made from Biodegradable Plastics on Smaller Fragmentation

    Science.gov (United States)

    Kudo, Makoto; Murata, Kenji; Kamata, Satoru; Hamada, Fumio

    In this paper, a new aerial shell made of biodegradable plastics was developed and explosion tests were carried out using 2.5-10 gou-size firework aerial shells at a ground test site in order to observe the fragmentation. The dispersed fragments were then collected and their size and distribution measured. In order to monitor the fragmentation visually, a high-speed camera was used to film the ignition of the bursting charge and the scattering of the shell fragments. The shell fragments became much smaller, because mechanical properties of biodegradable plastics that were added improved polyvinyl alcohol (PVA) and chaff powder (CP). Fibrillation was seen in PBS/PVA/CP, and it seemed effective for mechanical properties. As a result, safer aerial shells which disperse into smaller fragments on explosion were successfully developed.

  8. Syntrophic biodegradation of hydrocarbon contaminants.

    Science.gov (United States)

    Gieg, Lisa M; Fowler, S Jane; Berdugo-Clavijo, Carolina

    2014-06-01

    Anaerobic environments are crucial to global carbon cycling wherein the microbial metabolism of organic matter occurs under a variety of redox conditions. In many anaerobic ecosystems, syntrophy plays a key role wherein microbial species must cooperate, essentially as a single catalytic unit, to metabolize substrates in a mutually beneficial manner. Hydrocarbon-contaminated environments such as groundwater aquifers are typically anaerobic, and often methanogenic. Syntrophic processes are needed to biodegrade hydrocarbons to methane, and recent studies suggest that syntrophic hydrocarbon metabolism can also occur in the presence of electron acceptors. The elucidation of key features of syntrophic processes in defined co-cultures has benefited greatly from advances in 'omics' based tools. Such tools, along with approaches like stable isotope probing, are now being used to monitor carbon flow within an increasing number of hydrocarbon-degrading consortia to pinpoint the key microbial players involved in the degradative pathways. The metagenomic sequencing of hydrocarbon-utilizing consortia should help to further identify key syntrophic features and define microbial interactions in these complex communities. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Alcoholism & depression.

    Science.gov (United States)

    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.

  10. Hydrophobic hydration and anomalous excess partial molar volume of tert-butyl alcohol-water mixture studied by quasielastic neutron scattering

    International Nuclear Information System (INIS)

    Nakada, Masaru; Maruyama, Kenji; Misawa, Masakatsu; Yamamuro, Osamu

    2007-01-01

    Quasielastic neutron scattering has been used to investigate the hydration of alcohol clusters in tert-butyl alcohol-water mixture. The measurements were made in a range of alcohol concentration, x TBA , from 0.0 to 0.17 in mole fraction at 25degC. Fraction, α, of water molecules hydrated to fractal-surface of alcohol clusters in tert-butyl alcohol-water mixture was obtained as a function of alcohol concentration. Average hydration number N WS of tert-butyl alcohol molecule was derived from the value of α as a function of alcohol concentration. The value of N WS for an isolated alcohol molecule in water was 19-21. The anomalous excess partial molar volume of tert-butyl alcohol-water mixture was interpreted successfully by applying the same model with the same values of volume parameter as used for 1-propanol-water mixture, δ 1 (=-0.36 cm 3 ·mol -1 ) and δ 2 (=0.60 cm 3 ·mol -1 ). (author)

  11. NIAAA Alcohol Treatment Navigator

    Science.gov (United States)

    ... What to Know About Alcohol Treatment What Is Alcohol Use Disorder (AUD)? What Types of Alcohol Treatment Are Available? ... What to Know About Alcohol Treatment What is alcohol use disorder (AUD)? A health condition that can improve with ...

  12. Alcohol Energy Drinks

    Science.gov (United States)

    ... Month Home / About Addiction / Alcohol / Alcohol Energy Drinks Alcohol Energy Drinks Read 32794 times font size decrease ... held April 8-11 near the... Read more Alcohol Wine for your health: truth and myth Alcohol ...

  13. Alcohol and Hepatitis

    Science.gov (United States)

    ... code here Enter ZIP code here Daily Living: Alcohol for Veterans and the Public Alcohol and the Liver: Entire Lesson Overview Alcohol is ... provider or contact a Substance Use Disorder program Alcohol Drinking Diary and Change Plan Alcohol Drinking Diary ...

  14. Isopropanol alcohol poisoning

    Science.gov (United States)

    Rubbing alcohol poisoning; Isopropyl alcohol poisoning ... Isopropyl alcohol can be harmful if it is swallowed or gets in the eyes. ... These products contain isopropanol: Alcohol swabs Cleaning supplies ... Rubbing alcohol Other products may also contain isopropanol.

  15. Biodegradation of Moringa oleifera's polymer blends.

    Science.gov (United States)

    Finzi-Quintão, Cristiane Medina; Novack, Kátia Monteiro; Bernardes-Silva, Ana Cláudia; Silva, Thais D; Moreira, Lucas E S; Braga, Luiza E M

    2017-11-10

    Vegetable oils are used as a base for the synthesis of polymers and monomers with structures similar to that of petroleum, as plasticizers for conventional polymers and biodegrading additives. The Moringa oleifera oil was extracted from seeds and polymerized after being submitted to 16 h of microwave irradiation without catalysers. This polymer was characterized and the efficiency of the oil polymerization was verified by the reduction of double bonds and the increase of molecular weight up to 50,000 g mol -1 . Films produced by a mixture of low-density polyethylene (LDPE) with poly(butylene adipate-co-terephthalate)/poly(lactic acid) (PBAT/PLA) present low tensile resistance and low biodegradation behaviour. In order to improve those properties, the Moringa polymer (PMO) was mixed with LDPE and PBAT/PLA in specific mass concentrations. The films produced with this mixture were characterized and submitted to biodegradation analysis. The PMO behaves as a compatibilizer by improving thermal properties, reducing the crystalline phase and improving the biodegradation behaviour. The biodegradation improved up to five times in comparison to conventional polymers and it restores the mechanical properties.

  16. Biodegradable compounds: Rheological, mechanical and thermal properties

    Science.gov (United States)

    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.

  17. Biodegradability of degradable plastic waste.

    Science.gov (United States)

    Agamuthu, P; Faizura, Putri Nadzrul

    2005-04-01

    Plastic waste constitutes the third largest waste volume in Malaysian municipal solid waste (MSW), next to putrescible waste and paper. The plastic component in MSW from Kuala Lumpur averages 24% (by weight), whereas the national mean is about 15%. The 144 waste dumps in the country receive about 95% of the MSW, including plastic waste. The useful life of the landfills is fast diminishing as the plastic waste stays un-degraded for more than 50 years. In this study the compostability of polyethylene and pro-oxidant additive-based environmentally degradable plastics (EDP) was investigated. Linear low-density polyethylene (LLDPE) samples exposed hydrolytically or oxidatively at 60 degrees C showed that the abiotic degradation path was oxidative rather than hydrolytic. There was a weight loss of 8% and the plastic has been oxidized as shown by the additional carbonyl group exhibited in the Fourier transform infra red (FTIR) Spectrum. Oxidation rate seemed to be influenced by the amount of pro-oxidant additive, the chemical structure and morphology of the plastic samples, and the surface area. Composting studies during a 45-day experiment showed that the percentage elongation (reduction) was 20% for McD samples [high-density polyethylene, (HDPE) with 3% additive] and LL samples (LLDPE with 7% additive) and 18% reduction for totally degradable plastic (TDP) samples (HDPE with 3% additive). Lastly, microbial experiments using Pseudomonas aeroginosa on carbon-free media with degradable plastic samples as the sole carbon source, showed confirmatory results. A positive bacterial growth and a weight loss of 2.2% for degraded polyethylene samples were evident to show that the degradable plastic is biodegradable.

  18. Environmental properties of long chain alcohols. Part 1: Physicochemical, environmental fate and acute aquatic toxicity properties

    DEFF Research Database (Denmark)

    Fisk, Peter; Sanderson, Hans; Wildey, Ross

    2009-01-01

    )SARs). This allows predictions of data relating to human and environmental safety profiles and patterns. These alcohols have been shown to be rapidly degradable under standard conditions up to C18. Furthermore, evidence suggests that longer chain lengths are also rapidly biodegradable. While log Kow values suggest......This paper summarises the physicochemical, biodegradation and acute aquatic ecotoxicity properties of long chain aliphatic alcohols. Properties of pure compounds are shown to follow somewhat predictable trends, which are amenable to estimation by quantitative structure-activity relationships ((Q...

  19. Introduction of environmentally degradable parameters to evaluate the biodegradability of biodegradable polymers.

    Science.gov (United States)

    Guo, Wenbin; Tao, Jian; Yang, Chao; Song, Cunjiang; Geng, Weitao; Li, Qiang; Wang, Yuanyuan; Kong, Meimei; Wang, Shufang

    2012-01-01

    Environmentally Degradable Parameter ((Ed)K) is of importance in the describing of biodegradability of environmentally biodegradable polymers (BDPs). In this study, a concept (Ed)K 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 (Ed)K was used as an indicator for the ultimate biodegradability of materials. Starch and polyethylene used as reference materials were defined as the (Ed)K 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 (Ed)K for each material. The (Ed)K 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 (Ed)K was shown to be a reliable indicator for quantitatively evaluating the potential biodegradability of BDPs in the natural environment.

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

    Science.gov (United States)

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

    2012-01-01

    Environmentally Degradable Parameter (Ed K) is of importance in the describing of biodegradability of environmentally biodegradable polymers (BDPs). In this study, a concept Ed K 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 Ed K was used as an indicator for the ultimate biodegradability of materials. Starch and polyethylene used as reference materials were defined as the Ed K 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 Ed K for each material. The Ed K 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 Ed K was shown to be a reliable indicator for quantitatively evaluating the potential biodegradability of BDPs in the natural environment. PMID:22675455

  1. Effect of benzene and ethylbenzene on the transcription of methyl-tert-butyl ether degradation genes of Methylibium petroleiphilum PM1.

    Science.gov (United States)

    Joshi, Geetika; Schmidt, Radomir; Scow, Kate M; Denison, Michael S; Hristova, Krassimira R

    2016-09-01

    Methyl-tert-butyl ether (MTBE) and its degradation by-product, tert-butyl alcohol (TBA), are widespread contaminants detected frequently in groundwater in California. Since MTBE was used as a fuel oxygenate for almost two decades, leaking underground fuel storage tanks are an important source of contamination. Gasoline components such as BTEX (benzene, toluene, ethylbenzene and xylenes) are often present in mixtures with MTBE and TBA. Investigations of interactions between BTEX and MTBE degradation have not yielded consistent trends, and the molecular mechanisms of BTEX compounds' impact on MTBE degradation are not well understood. We investigated trends in transcription of biodegradation genes in the MTBE-degrading bacterium, Methylibium petroleiphilum PM1 upon exposure to MTBE, TBA, ethylbenzene and benzene as individual compounds or in mixtures. We designed real-time quantitative PCR assays to target functional genes of strain PM1 and provide evidence for induction of genes mdpA (MTBE monooxygenase), mdpJ (TBA hydroxylase) and bmoA (benzene monooxygenase) in response to MTBE, TBA and benzene, respectively. Delayed induction of mdpA and mdpJ transcription occurred with mixtures of benzene and MTBE or TBA, respectively. bmoA transcription was similar in the presence of MTBE or TBA with benzene as in their absence. Our results also indicate that ethylbenzene, previously proposed as an inhibitor of MTBE degradation in some bacteria, inhibits transcription of mdpA, mdpJ and bmoAgenes in strain PM1.

  2. Biodegradable Polymers and Stem Cells for Bioprinting

    Directory of Open Access Journals (Sweden)

    Meijuan Lei

    2016-04-01

    Full Text Available 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.

  3. Biodegradable Polymers and Stem Cells for Bioprinting.

    Science.gov (United States)

    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.

  4. Biodegradation of dissolved humic substances by fungi.

    Science.gov (United States)

    Collado, Sergio; Oulego, Paula; Suárez-Iglesias, Octavio; Díaz, Mario

    2018-04-01

    Humic and fulvic acids constitute humic substances, a complex mixture of many different acids containing carboxyl and phenolate groups, which are not only the principal soil fertility factors but also the main pollutants present in landfill leachates or natural organic matter in water. Due to their low bacterial biodegradability, fungal biodegradation processes are key for their removal. The present study compiles and comments all the available literature on decomposition of aqueous humic substances by fungi or by their extracellular enzymes alone, focusing on the influence of the reaction conditions. The biodegradation extent mainly depends on the characteristics and concentration of the humic compounds, the type of microorganisms selected, the inoculation mode, the C and N sources, the presence of certain chemicals in the medium, the availability of oxygen, the temperature, and the pH.

  5. Biodegradable nanoparticles for gene therapy technology

    International Nuclear Information System (INIS)

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

    2013-01-01

    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

  6. Biodegradation of 2-ethylhexyl nitrate by Mycobacterium austroafricanum IFP 2173

    International Nuclear Information System (INIS)

    Nicolau, E.

    2008-10-01

    Compounds such as 2-ethylhexyl nitrate (2-EHN) are added to diesel fuel to improve ignition and boost cetane number. The production of 2-EHN reaches around 100000 tons per year in France, principally. Risks associated to its utilization are however poorly known because, in case of accidental release in the environment, nothing is known about its biodegradation. In this study, we aimed at (i) identifying bacterial strains able to degrade 2-EHN and compare their capabilities, (ii) elucidating the degradation pathway, and (iii) identifying the enzymes involved. Biodegradation of 2-EHN was first tested in biphasic cultures under conditions that reduce the toxicity and increase the availability of the hydrophobic substrate. Using optimized culture conditions, we showed that several strains of Mycobacterium austroafricanum were able to degrade 2-EHN. One of the most efficient strain (IFP 2173) which could grow at 2-EHN concentrations up to 6 g.L -1 , was chosen to investigate the degradation pathway. On the basis of carbon balance determination and gas chromatographic (GC) analysis on the culture medium, I found that the degradation of 2-EHN was incomplete and gave rise to the accumulation of a metabolite. This metabolite was identified as β-methyl-γ-butyrolactone by GC-MS and LC-MS/MS analysis. The structure of the lactone indicated that 2-EHN was degraded through a pathway involving the hydroxylation of the methyl group of the main carbon chain, its oxidation into aldehyde an acid and a subsequent cycle of b-oxidation. Enzymes involved in the 2-EHN biodegradation pathway were looked for by a proteomic approach. Analyses by two-dimensional gel electrophoresis showed that, when exposed to 2-EHN, strain IFP 2173 triggered the synthesis of a bunch of enzymes specialized in fatty acid metabolism such as β-oxidation enzymes, as well as alcohol and aldehyde dehydrogenases. An exhaustive analysis of the IFP 2173 proteome resulted in the identification of more than 200

  7. Biodegradable polyesters based on succinic acid

    Directory of Open Access Journals (Sweden)

    Nikolić Marija S.

    2003-01-01

    Full Text Available Two series of aliphatic polyesters based on succinic acid were synthesized by copolymerization with adipic acid for the first series of saturated polyesters, and with fumaric acid for the second series. Polyesters were prepared starting from the corresponding dimethyl esters and 1,4-butanediol by melt transesterification in the presence of a highly effective catalyst tetra-n-butyl-titanate, Ti(0Bu4. The molecular structure and composition of the copolyesters was determined by 1H NMR spectroscopy. The effect of copolymer composition on the physical and thermal properties of these random polyesters were investigated using differential scanning calorimetry. The degree of crystallinity was determined by DSC and wide angle X-ray. The degrees of crystallinity of the saturated and unsaturated copolyesters were generally reduced with respect to poly(butylene succinate, PBS. The melting temperatures of the saturated polyesters were lower, while the melting temperatures of the unsaturated copolyesters were higher than the melting temperature of PBS. The biodegradability of the polyesters was investigated by enzymatic degradation tests. The enzymatic degradation tests were performed in a buffer solution with Candida cylindracea lipase and for the unsaturated polyesters with Rhizopus arrhizus lipase. The extent of biodegradation was quantified as the weight loss of polyester films. Also the surface of the polyester films after degradation was observed using optical microscopy. It could be concluded that the biodegradability depended strongly on the degree of crystallinity, but also on the flexibility of the chain backbone. The highest biodegradation was observed for copolyesters containing 50 mol.% of adipic acid units, and in the series of unsaturated polyesters for copolyesters containing 5 and 10 mol.% of fumarate units. Although the degree of crystallinity of the unsaturated polyesters decreased slightly with increasing unsaturation, the biodegradation

  8. Histological evaluation of different biodegradable and non-biodegradable membranes implanted subcutaneously in rats

    DEFF Research Database (Denmark)

    Zhao, S; Pinholt, E M; Madsen, J E

    2000-01-01

    Different types of biodegradable membranes have become available for guided tissue regeneration. The purpose of this study was to evaluate histologically three different biodegradable membranes (Bio-Gide, Resolut and Vicryl) and one non-biodegradable membrane (expanded polytetrafluoroethylene/e-PTFE...... that e-PTFE was well tolerated and encapsulated by a fibrous connective tissue capsule. There was capsule formation around Resolut and Vicryl and around Bio-Gide in the early phase there was a wide inflammatory zone already. e-PTFE and Vicryl were stable materials while Resolut and Bio-Gide fragmented...

  9. Alcohol Facts

    Science.gov (United States)

    ... Peter is recovering from an alcohol addiction. The addiction grew slowly over many years. Read Peter's story Treatment & Recovery Information Treatment and Recovery Does Drug Treatment Work? Treatment and Rehab Resources About the National Institute ...

  10. Biodegradable containers from green waste materials

    Science.gov (United States)

    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.

  11. Biodegradation of Crystal Violet by Agrobacterium radiobacter

    DEFF Research Database (Denmark)

    Parshetti, G.K.; Parshetti, S.G.; Telke, A.A.

    2011-01-01

    Violet (100 mg/L) was studied, maximum decolorization was observed with 15% inoculum concentration. A significant increase in the activities of laccase (184%) and aminopyrine Af-demethylase (300%) in cells obtained after decolorization indicated the involvement of these enzymes in decolorization process...... and phenol. We proposed the hypothetical metabolic pathway of Crystal Violet biodegradation by A. radiobacter. Phytotoxicity and microbial toxicity study showed that Crystal Violet biodegradation metabolites were less toxic to bacteria (A. radiobacter, P. aurugenosa and A. vinelandii) contributing to soil...

  12. Biodegradable multifunctional oil production chemicals: Thermal polyaspartates

    International Nuclear Information System (INIS)

    Ross, R.J.; Ravenscroft, P.D.

    1996-01-01

    The paper deals with biodegradable oil production chemicals. Control of both mineral scale and corrosion with a single, environmentally acceptable material is an ambitious goal. Polyaspartate polymers represent a significant milestone in the attainment of this goal. Thermal polyaspartates (TPA) are polycarboxylate polymers derived via thermal condensation of the naturally occurring amino acid aspartic acid. These protein-like polymers are highly biodegradable and non-toxic, and are produced by an environmentally benign manufacturing process. TPAs exhibit excellent mineral scale inhibition activity and CO 2 corrosion control. Laboratory data on scale inhibition and corrosion control in the North Sea oil field production applications is presented. 8 refs., 2 figs., 6 tabs

  13. Anaerobic biodegradability and treatment of Egyption domestic sewage

    NARCIS (Netherlands)

    Elmitwally, T.A.; Al-Sarawey, A.; El-Sherbiny, M.F.; Zeeman, G.; Lettinga, G.

    2003-01-01

    The anaerobic biodegradability of domestic sewage for four Egyptian villages and four Egyptian cities was determined in batch experiments. The results showed that the biodegradability of the Egyptian-villages sewage (73%) was higher than that of the cities (66%). The higher biodegradability of the

  14. Synthetic biodegradable functional polymers for tissue engineering: a brief review

    OpenAIRE

    BaoLin, GUO; MA, Peter X.

    2014-01-01

    Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly (glyce...

  15. Anti-Fusarium moniliforme activity and fumonisin biodegradation by corn and silage microflora

    Directory of Open Access Journals (Sweden)

    Simone B. Camilo

    2000-01-01

    Full Text Available Studies were carried out to isolate microorganisms from corn and silage screened for their ability to inhibit F. moniliforme growth (strain 113F in association with fumonisin detoxification. Among 150 isolates four Gram-positive bacilli and one yeast with inhibitory activity were selected. The inhibition zone ranged from 50 to 72.5 mm using cultures, and from 25 to 52.5mm for crude alcoholic extract. The isolates S9, S10, S69 (sporulated bacilli and SE3071 (yeast degraded 43, 48, 83 and 57% of the initial FB1 concentration, respectively. The pH increased gradually in the medium during incubation for biodegradation process.

  16. Biodegradable polymers by reactive blending trans-esterification of thermoplastic starch with poly (vinyl acetate) and poly (vinyl acetate-co-butyl acrylate)

    CSIR Research Space (South Africa)

    Vargha, V

    2005-04-01

    Full Text Available (vinyl alcohol- co-acetate) is expected. The internally plasticized PVAC, i.e. poly(vinyl acetate-co-butyl acrylate), would serve to decrease the glass transition temperature range of the resulting blend. Both polymers are sold as biodegradable by the supplier... stream_source_info vargha_2005.pdf.txt stream_content_type text/plain stream_size 37663 Content-Encoding ISO-8859-1 stream_name vargha_2005.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Biodegradable polymers...

  17. Biodegradation of norfloxacin by Penicillium frequentans isolated ...

    African Journals Online (AJOL)

    One norfloxacin-degrading fungi was isolated from soil contaminated by norfloxacin and preliminary identified as Penicillium frequentans. Indoor simulative degradation experiments were carried out to investigate the biodegradation kinetics of norfloxacin with or without NFX3 in soil. The results indicate that the ...

  18. Formulation and characterization of caffeine biodegradable chewing ...

    African Journals Online (AJOL)

    ) is a test for analysing the textural properties of food, in which the samples are ..... Food Technol 1978;. 32: 62-66. 16. Mehta FM, Trivedi P. Formulation and characterization of biodegradable medicated chewing gum delivery system for motion ...

  19. Production of Polyhydroxyalkanoates, a bacterial biodegradable ...

    African Journals Online (AJOL)

    Administrator

    There has been considerable interest in the development and production of biodegradable polymer to solve the current problem of pollution caused ... horticultural agricultural waste, corn, cassava etc would be of economic interest considering the .... for efficient production of PHAs. (Yu, 2001, Du et al.,. 2001b; Du and Yu, ...

  20. Preparation of Natural and Synthetic Porous Biodegradable ...

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. Preparation of Natural and Synthetic Porous Biodegradable Scaffolds for Infected Wounds. Characterised for their physical properties, pore size and release kinetics. Release kinetics of bioactive molecules (antibiotics) in a controlled fashion. Release pattern of the ...

  1. Production of Polyhydroxyalkanoates, a bacterial biodegradable ...

    African Journals Online (AJOL)

    ... production has restricted its applications. The possibility of producing this polymer commercially and at comparable cost has been the main focus in this area. Key Words: Polyhydroxyalkanoates, biodegradable polymer, bioplastic, poly(3-hydroxybutyrate), biosynthesis. African Journal of Biotechnology Vol.3(1) 2004: 18- ...

  2. Biodegradable polymers derived from amino acids.

    Science.gov (United States)

    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. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Biodegradable Shape Memory Polymers in Medicine.

    Science.gov (United States)

    Peterson, Gregory I; Dobrynin, Andrey V; Becker, Matthew L

    2017-11-01

    Shape memory materials have emerged as an important class of materials in medicine due to their ability to change shape in response to a specific stimulus, enabling the simplification of medical procedures, use of minimally invasive techniques, and access to new treatment modalities. Shape memory polymers, in particular, are well suited for such applications given their excellent shape memory performance, tunable materials properties, minimal toxicity, and potential for biodegradation and resorption. This review provides an overview of biodegradable shape memory polymers that have been used in medical applications. The majority of biodegradable shape memory polymers are based on thermally responsive polyesters or polymers that contain hydrolyzable ester linkages. These materials have been targeted for use in applications pertaining to embolization, drug delivery, stents, tissue engineering, and wound closure. The development of biodegradable shape memory polymers with unique properties or responsiveness to novel stimuli has the potential to facilitate the optimization and development of new medical applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Evaluation of biodegradation and biocompatibility of collagen ...

    Indian Academy of Sciences (India)

    The aim of this study was to develop a new variant of membranes based on collagen (COL), chitosan (CHI) and alkaline phosphatase (ALP) immobilized and cross-linking with glutaraldehyde (GA) at different concentrations. The biodegradation in the presence of collagenase was investigated. Biocompatibility was ...

  5. hydrocarbons biodegradation and evidence of mixed petroleum ...

    African Journals Online (AJOL)

    DJFLEX

    mode (EI) at 70Ev ionisation energy and scanned from 50 to 650 dalton. 3.0 Result and discussion. 3.1 n-alkanes and Isoprenoid Hydrocarbons. The concentrations (mgkg-1) ..... community in the Yellowish geothermal environment. Nature 434, 1000-1014. Cross River System. HYDROCARBONS BIODEGRADATION AND ...

  6. Fate and biodegradability of sulfonated aromatic amines

    NARCIS (Netherlands)

    Tan, N.C.G.; Leeuwen, van A.; Voorthuizen, van E.M.; Slenders, P.; Prenafeta, F.X.; Temmink, H.; Lettinga, G.; Field, J.A.

    2005-01-01

    Ten sulfonated aromatic amines were tested for their aerobic and anaerobic biodegradability and toxicity potential in a variety of environmental inocula. Of all the compounds tested, only two aminobenzenesulfonic acid (ABS) isomers, 2- and 4-ABS, were degraded. The observed degradation occurred only

  7. Evaluation of biodegradation and biocompatibility of collagen ...

    Indian Academy of Sciences (India)

    The biodegradation in the presence of collagenase was investigated. Biocompatibility was evaluated by MTT assay using a mouse fibroblast cell culture type NCTC (clone 929). Non-cross-linked samples were biocompatible and membranes cross-linked with low concentrations of GA (0.04, 0.08%) were also iocompatible.

  8. Biodegradability of diesel and biodiesel blends

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-02

    May 2, 2008 ... The biodegradability of pure diesel and biodiesel and blends with different proportions of biodiesel (2%. (commercial); 5% and 20%) was evaluated employing the respirometric method and the redox indicator. 2,6-dichlorophenol indophenol (DCPIP) test. In the former, experiments simulating the ...

  9. Modeling aerobic biodegradation in the capillary fringe.

    Science.gov (United States)

    Luo, Jian; Kurt, Zohre; Hou, Deyi; Spain, Jim C

    2015-02-03

    Vapor intrusion from volatile subsurface contaminants can be mitigated by aerobic biodegradation. Laboratory column studies with contaminant sources of chlorobenzene and a mixture of chlorobenzene, 1,2-dichlorobenzene, and 1,4-dichlorobenzene showed that contaminants were rapidly degraded in thin reactive zones with high biomass and low substrate concentrations in the vicinity of the capillary fringe. Such behavior was well characterized by a model that includes oxygen-, substrate-, and biomass-dependent biodegradation kinetics along with diffusive transport processes. An analytical solution was derived to provide theoretical support for the simplification of reaction kinetics and the approximation of reactive zone location and mass flux relationships at steady state. Results demonstrate the potential of aerobic natural attenuation in the capillary fringe for preventing contaminant migration in the unsaturated zone. The solution indicates that increasing contaminant mass flux into the column creates a thinner reactive zone and pushes it toward the oxygen boundary, resulting in a shorter distance to the oxygen source and a larger oxygen mass flux that balances the contaminant mass flux. As a consequence, the aerobic biodegradation can reduce high contaminant concentrations to low levels within the capillary fringe and unsaturated zone. The results are consistent with the observations of thin reactive layers at the interface in unsaturated zones. The model considers biomass while including biodegradation in the capillary fringe and unsaturated zone and clearly demonstrates that microbial communities capable of using the contaminants as electron donors may lead to instantaneous degradation kinetics in the capillary fringe and unsaturated zone.

  10. Diisopropanolamine biodegradation potential at sour gas plants

    Energy Technology Data Exchange (ETDEWEB)

    Gieg, L.M.; Greene, E.A.; Coy, D.L.; Fedorak, P.M.

    1998-12-31

    The potential for aerobic and anaerobic biodegradation of a sour gas treatment chemical, diisopropanolamine (DIPA), was studied using contaminated aquifer materials from three sour gas treatment sites in western Canada. DIPA was found to be readily consumed under aerobic conditions at 8 C and 28 C in shake flask cultures incubated with aquifer material from each of the sites, and this removal was characterized by first-order kinetics. In addition, DIPA biodegradation was found to occur under nitrate-, Mn(IV)-, and Fe(III)-reducing conditions at 28 C, and in some cases at 8 C, in laboratory microcosms. DIPA loss corresponded to consumption of nitrate, and production of Mn(II) and Fe(II) in viable microcosms compared to corresponding sterile controls. A threshold DIPA concentration near 40 mg/L was observed in the anaerobic microcosms. This report provides the first evidence that DIPA is biodegraded under anaerobic conditions, and the data suggest that biodegradation may contribute to DIPA attenuation under aerobic and anaerobic conditions in aquifers contaminated with this sour gas treatment chemical.

  11. Current trends in trichloroethylene biodegradation: a review.

    Science.gov (United States)

    Shukla, Awadhesh Kumar; Upadhyay, Siddh Nath; Dubey, Suresh Kumar

    2014-06-01

    Over the past few years biodegradation of trichloroethylene (TCE) using different microorganisms has been investigated by several researchers. In this review article, an attempt has been made to present a critical summary of the recent results related to two major processes--reductive dechlorination and aerobic co-metabolism used for TCE biodegradation. It has been shown that mainly Clostridium sp. DC-1, KYT-1, Dehalobacter, Dehalococcoides, Desulfuromonas, Desulfitobacterium, Propionibacterium sp. HK-1, and Sulfurospirillum bacterial communities are responsible for the reductive dechlorination of TCE. Efficacy of bacterial communities like Nitrosomonas, Pseudomonas, Rhodococcus, and Xanthobacter sp. etc. for TCE biodegradation under aerobic conditions has also been examined. Mixed cultures of diazotrophs and methanotrophs have been used for TCE degradation in batch and continuous cultures (biofilter) under aerobic conditions. In addition, some fungi (Trametes versicolor, Phanerochaete chrysosporium ME-446) and Actinomycetes have also been used for aerobic biodegradation of TCE. The available information on kinetics of biofiltration of TCE and its degradation end-products such as CO2 are discussed along with the available results on the diversity of bacterial community obtained using molecular biological approaches. It has emerged that there is a need to use metabolic engineering and molecular biological tools more intensively to improve the robustness of TCE degrading microbial species and assess their diversity.

  12. Biodegradable poly (lactic acid) microspheres containing total ...

    Indian Academy of Sciences (India)

    The fabrication of biodegradable poly(lactic acid) (PLA) microspheres containing total alkaloids of Caulis sinomenii was investigated. The formation, diameter, morphology and properties of the microspheres were characterized using Fourier transform infrared spectroscopy (FT–IR), laser particle size analyser and scanning ...

  13. Biodegradation of chlorobenzoic acids by ligninolytic fungi

    Czech Academy of Sciences Publication Activity Database

    Muzikář, Milan; Křesinová, Zdena; Svobodová, Kateřina; Filipová, Alena; Čvančarová, Monika; Cajthamlová, Kamila; Cajthaml, Tomáš

    2011-01-01

    Roč. 196, - (2011), s. 386-394 ISSN 0304-3894 R&D Projects: GA MŠk 2B06156; GA ČR GA525/09/1058 Institutional research plan: CEZ:AV0Z50200510 Keywords : Chlorobenzoic acid * Polychlorinated biphenyls * Biodegradation Subject RIV: EE - Microbiology, Virology Impact factor: 4.173, year: 2011

  14. Biodegradation of synthetic detergents in wastewater

    African Journals Online (AJOL)

    STORAGESEVER

    2009-03-20

    Mar 20, 2009 ... Surfactants constitute a major ingredient of detergent components. Usually surfactants are disposed after use to sewage treatment plants (STPs). Here, biodegradation processes and adsorption on sludge particles remove these chemicals from wastewaters to a greater or lesser extent, depending on the ...

  15. Biodegradable polymersomes for targeted ultrasound imaging

    NARCIS (Netherlands)

    Zhou, W.; Hennink, W.E.; Feijen, J.; Meng, Fenghua; Sam, T; Engbers, G.H.M.; Feijen, Jan

    2006-01-01

    Biodegradable polymersomes with a sub-micron size were prepared by using poly(ethylene glycol)–polylactide (PEG–PDLLA) block-copolymers in aqueous media. Air-encapsulated polymersomes could be obtained by a lyophilization/rehydration procedure. Preliminary results showed that these polymersomes were

  16. Biodegradation of uranium-contaminated waste oil

    International Nuclear Information System (INIS)

    Hary, L.F.

    1983-01-01

    The Portsmouth Gaseous Diffusion Plant routinely generates quantities of uranium-contaminated waste oil. The current generation rate of waste oil is approximately 2000 gallons per year. The waste is presently biodegraded by landfarming on open field soil plots. However, due to the environmental concerns associated with this treatment process, studies were conducted to determine the optimum biodegradation conditions required for the destruction of this waste. Tests using respirometric flasks were conducted to determine the biodegradation rate for various types of Portsmouth waste oil. These tests were performed at three different loading rates, and on unfertilized and fertilized soil. Additional studies were conducted to evaluate the effectiveness of open field landfarming versus treatment at a greenhouse-like enclosure for the purpose of maintaining soil temperatures above ambient conditions. The respirometric tests concluded that the optimum waste oil loading rate is 10% weight of oil-carbon/weight of soil (30,600 gallons of uranium-contaminated waste oil/acre) on soils with adjusted carbon:nitrogen and carbon:phosphorus ratios of 60:1 and 800:1, respectively. Also, calculational results indicated that greenhouse technology does not provide a significant increase in biodegradation efficiency. Based on these study results, a 6300 ft. 2 abandoned anaerobic digester sludge drying bed is being modified into a permanent waste oil biodegradation facility. The advantage of using this area is that uranium contamination will be contained by the bed's existing leachate collection system. This modified facility will be capable of handling approximately 4500 gallons of waste oil per year; accordingly current waste generation quantities will be satisfactorily treated. 15 refs., 14 figs., 4 tabs

  17. Improving the biodegradative capacity of subsurface bacteria

    Energy Technology Data Exchange (ETDEWEB)

    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.

  18. Improving the biodegradative capacity of subsurface bacteria

    International Nuclear Information System (INIS)

    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

  19. Hydrocarbons biodegradation in unsaturated porous medium

    International Nuclear Information System (INIS)

    Gautier, C.

    2007-12-01

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

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

    DEFF Research Database (Denmark)

    Tolstrup, J.S.; Nordestgaard, Børge; Rasmussen, S.

    2008-01-01

    /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......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...

  1. What We Fund - Alcohol

    International Development Research Centre (IDRC) Digital Library (Canada)

    NCDP

    national and international by ... Marketing restrictions, such as. Reducing availability of retailed alcohol. Bans on alcohol advertizing, ... relationships between alcohol consumption and household poverty (e.g. the opportunity costs of alcohol).

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

    Science.gov (United States)

    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. Copyright © 2015 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  3. Inhibition of Biodegradation of Hydraulic Fracturing Compounds by Glutaraldehyde: Groundwater Column and Microcosm Experiments.

    Science.gov (United States)

    Rogers, Jessica D; Ferrer, Imma; Tummings, Shantal S; Bielefeldt, Angela R; Ryan, Joseph N

    2017-09-05

    The rapid expansion of unconventional oil and gas development has raised concerns about the potential contamination of aquifers; however, the groundwater fate and transport of hydraulic fracturing fluid compounds and mixtures remains a significant data gap. Degradation kinetics of five hydraulic fracturing compounds (2-propanol, ethylene glycol, propargyl alcohol, 2-butoxyethanol, and 2-ethylhexanol) in the absence and presence of the biocide glutaraldehyde were investigated under a range of redox conditions using sediment-groundwater microcosms and flow-through columns. Microcosms were used to elucidate biodegradation inhibition at varying glutaraldehyde concentrations. In the absence of glutaraldehyde, half-lives ranged from 13 d to >93 d. Accurate mass spectrometry indicated that a trimer was the dominant aqueous-phase glutaraldehyde species. Microbial inhibition was observed at glutaraldehyde trimer concentrations as low as 5 mg L -1 , which demonstrated that the trimer retained some biocidal activity. For most of the compounds, biodegradation rates slowed with increasing glutaraldehyde concentrations. For many of the compounds, degradation was faster in the columns than the microcosms. Four compounds (2-propanol, ethylene glycol, propargyl alcohol, and 2-butoxyethanol) were found to be both mobile and persistent in groundwater under a range of redox conditions. The glutaraldehyde trimer and 2-ethylhexanol were more rapidly degraded, particularly under oxic conditions.

  4. [Biodegradable catheters and urinary stents. When?

    Science.gov (United States)

    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

  5. Overview of Alcohol Consumption

    Science.gov (United States)

    ... of Alcohol Consumption Alcohol's Effects on the Body Alcohol Use Disorder Fetal Alcohol Exposure Support & Treatment Alcohol Policy Special ... experience alcohol’s longer-term effects, which can include: Alcohol use disorder Health problems Increased risk for certain cancers In ...

  6. Alcohol Poisoning

    Science.gov (United States)

    ... Get follow-up care. If you or your teen has been treated for alcohol poisoning, be sure to ask about follow-up care. Meeting with a health professional, particularly an experienced chemical dependency professional, can help you prevent future binge drinking. By Mayo Clinic Staff . Mayo Clinic ...

  7. ALCOHOL I

    African Journals Online (AJOL)

    although sales promotions affected stu- dents from Australia and Germany, Welsh students were more likely to purchase alcohol during promotions, because of their intention to take advantage of price discounts. In the Philippines, Swahn et al. (2013) revealed that promotional ac- tivities offering free drinks to students.

  8. Current knowledge on biodegradable microspheres in drug delivery.

    Science.gov (United States)

    Prajapati, Vipul D; Jani, Girish K; Kapadia, Jinita R

    2015-08-01

    Biodegradable microspheres have gained popularity for delivering a wide variety of molecules via various routes. These types of products have been prepared using various natural and synthetic biodegradable polymers through suitable techniques for desired delivery of various challenging molecules. Selection of biodegradable polymers and technique play a key role in desired drug delivery. This review describes an overview of the fundamental knowledge and status of biodegradable microspheres in effective delivery of various molecules via desired routes with consideration of outlines of various compendial and non-compendial biodegradable polymers, formulation techniques and release mechanism of microspheres, patents and commercial biodegradable microspheres. There are various advantages of using biodegradable polymers including promise of development with different types of molecules. Biocompatibility, low dosage and reduced side effects are some reasons why usage biodegradable microspheres have gained in popularity. Selection of biodegradable polymers and formulation techniques to create microspheres is the biggest challenge in research. In the near future, biodegradable microspheres will become the eco-friendly product for drug delivery of various genes, hormones, proteins and peptides at specific site of body for desired periods of time.

  9. Biodegradation of Volatile Organic Compounds and Their Effects on Biodegradability under Co-Existing Conditions

    Science.gov (United States)

    Yoshikawa, Miho; Zhang, Ming; Toyota, Koki

    2017-01-01

    Volatile organic compounds (VOCs) are major pollutants that are found in contaminated sites, particularly in developed countries such as Japan. Various microorganisms that degrade individual VOCs have been reported, and genomic information related to their phylogenetic classification and VOC-degrading enzymes is available. However, the biodegradation of multiple VOCs remains a challenging issue. Practical sites, such as chemical factories, research facilities, and illegal dumping sites, are often contaminated with multiple VOCs. In order to investigate the potential of biodegrading multiple VOCs, we initially reviewed the biodegradation of individual VOCs. VOCs include chlorinated ethenes (tetrachloroethene, trichloroethene, dichloroethene, and vinyl chloride), BTEX (benzene, toluene, ethylbenzene, and xylene), and chlorinated methanes (carbon tetrachloride, chloroform, and dichloromethane). We also summarized essential information on the biodegradation of each kind of VOC under aerobic and anaerobic conditions, together with the microorganisms that are involved in VOC-degrading pathways. Interactions among multiple VOCs were then discussed based on concrete examples. Under conditions in which multiple VOCs co-exist, the biodegradation of a VOC may be constrained, enhanced, and/or unaffected by other compounds. Co-metabolism may enhance the degradation of other VOCs. In contrast, constraints are imposed by the toxicity of co-existing VOCs and their by-products, catabolite repression, or competition between VOC-degrading enzymes. This review provides fundamental, but systematic information for designing strategies for the bioremediation of multiple VOCs, as well as information on the role of key microorganisms that degrade VOCs. PMID:28904262

  10. Biodegradation of Volatile Organic Compounds and Their Effects on Biodegradability under Co-Existing Conditions.

    Science.gov (United States)

    Yoshikawa, Miho; Zhang, Ming; Toyota, Koki

    2017-09-27

    Volatile organic compounds (VOCs) are major pollutants that are found in contaminated sites, particularly in developed countries such as Japan. Various microorganisms that degrade individual VOCs have been reported, and genomic information related to their phylogenetic classification and VOC-degrading enzymes is available. However, the biodegradation of multiple VOCs remains a challenging issue. Practical sites, such as chemical factories, research facilities, and illegal dumping sites, are often contaminated with multiple VOCs. In order to investigate the potential of biodegrading multiple VOCs, we initially reviewed the biodegradation of individual VOCs. VOCs include chlorinated ethenes (tetrachloroethene, trichloroethene, dichloroethene, and vinyl chloride), BTEX (benzene, toluene, ethylbenzene, and xylene), and chlorinated methanes (carbon tetrachloride, chloroform, and dichloromethane). We also summarized essential information on the biodegradation of each kind of VOC under aerobic and anaerobic conditions, together with the microorganisms that are involved in VOC-degrading pathways. Interactions among multiple VOCs were then discussed based on concrete examples. Under conditions in which multiple VOCs co-exist, the biodegradation of a VOC may be constrained, enhanced, and/or unaffected by other compounds. Co-metabolism may enhance the degradation of other VOCs. In contrast, constraints are imposed by the toxicity of co-existing VOCs and their by-products, catabolite repression, or competition between VOC-degrading enzymes. This review provides fundamental, but systematic information for designing strategies for the bioremediation of multiple VOCs, as well as information on the role of key microorganisms that degrade VOCs.

  11. Research of the biodegradability of degradable/biodegradable plastic material in various types of environments

    Directory of Open Access Journals (Sweden)

    Dana Adamcová

    2017-04-01

    Full Text Available Research was carried out in order to assess biodegradability of degradable/biodegradable materials made of HDPE and mixed with totally degradable plastic additive (TDPA additive or made of polyethylene (PE with the addition of pro-oxidant additive (d2w additive, advertised as 100% degradable or certifi ed as compostable within various types of environments. Research conditions were: (i controlled composting environment – laboratory-scale, (ii real composting conditions – domestic compost bin, (iii real composting conditions – industrial composting plant and (iv landfill conditions. The results demonstrate that the materials made of HDPE and mixed with totally degradable plastic additive (TDPA additive or made of polyethylene (PE with the addition of pro-oxidant additive (d2w additive or advertised as 100% degradable did not biodegrade in any of the above-described conditions and remained completely intact at the end of the tests. Biodegradation of the certified compostable plastic bags proceeded very well in laboratory-scale conditions and in real composting conditions – industrial composting plant, however, these materials did not biodegrade in real composting conditions – domestic compost bin and landfill conditions.

  12. Nanoparticles from Degradation of Biodegradable Plastic Mulch

    Science.gov (United States)

    Flury, Markus; Sintim, Henry; Bary, Andy; English, Marie; Schaefer, Sean

    2017-04-01

    Plastic mulch films are commonly used in crop production. They provide multiple benefits, including control of weeds and insects, increase of soil and air temperature, reduction of evaporation, and prevention of soil erosion. The use of plastic mulch film in agriculture has great potential to increase food production and security. Plastic mulch films must be retrieved and disposed after usage. Biodegradable plastic mulch films, who can be tilled into the soil after usage offer great benefits as alternative to conventional polyethylene plastic. However, it has to be shown that the degradation of these mulches is complete and no micro- and nanoparticles are released during degradation. We conducted a field experiment with biodegradable mulches and tested mulch degradation. Mulch was removed from the field after the growing season and composted to facilitate degradation. We found that micro- and nanoparticles were released during degradation of the mulch films in compost. This raises concerns about degradation in soils as well.

  13. Modeling ready biodegradability of fragrance materials.

    Science.gov (United States)

    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. © 2015 SETAC.

  14. Biodegradation and Transformation of Nitroaromatic Compounds (POSTPRINT)

    Science.gov (United States)

    2012-07-01

    From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT... MAR -1997 Biodegradation and Transformation of Nitroaromatic Compounds (POSTPRINT) 1900B56A Nishino, Shirley F.; Spain, Jim C. Armstrong Laboratory...space to accommodate bulk matter, and con· cainment of leachates. Generally, not more than 10% of the composting pile can be contaminate d soil (66

  15. Biodegradation of PCDDs/PCDFs and PCBs

    OpenAIRE

    Urbaniak, Magdalena

    2013-01-01

    Rozdział 4 książki Biodegradation - Engineering and Technology Edited by Rolando Chamy and Francisca Rosenkranz • “Innovative resources and effective methods of safety improvement and durability of buildings and transport infrastructure in the sustainable development” financed by the European Union, from the European Fund of Regional Development based on the Operational Programme of the Innovative Economy, POIG.01.01.02-10-106/09

  16. Methotrexate-loaded biodegradable nanoparticles: preparation ...

    Indian Academy of Sciences (India)

    Administrator

    effects as well as to achieve anticipated sustained release properties. In recent years, biodegradable polymeric ... 8 h and lyophilized with vacuum pressure of < 50 mTorr and at a temperature of –40 °C for 48 h. ... out in dialysis tubing using phosphate buffer pH 6∙8 at. 37 ± 0∙5 °C and at 50 rpm. In vitro drug release was.

  17. Biodegradation of ion-exchange media

    International Nuclear Information System (INIS)

    Bowerman, B.S.; Clinton, J.H.; Cowdery, S.R.

    1988-08-01

    Ion-exchange media, both bead resins and powdered filter media, are used in nuclear power plants to remove radioactivity from process water prior to reuse or environmental discharge. Since the ion- exchange media are made from synthetic hydrocarbon-based polymers, they may be susceptible to damage from biological activity. The purpose of this study was to investigate some of the more basic aspects of biodegradation of ion-exchange media, specifically to evaluate the ability of microorganisms to utilize the ion-exchange media or materials sorbed on them as a food source. The ASTM-G22 test, alone and combined with the Bartha Pramer respirometric method, failed to indicate the biodegradability of the ion-exchange media. The limitation of these methods was that they used a single test organism. In later phases of this study, a mixed microbial culture was grown from resin waste samples obtained from the BNL High Flux Beam Reactor. These microorganisms were used to evaluate the susceptibility of different types of ion-exchange media to biological attack. Qualitative assessments of biodegradability were based on visual observations of culture growths. Greater susceptibility was associated with increased turbidity in solution indicative of bacterial growth, and more luxuriant fungal mycelial growth in solution or directly on the ion-exchange resin beads. 21 refs., 9 figs., 18 tabs

  18. Corexit 9500 Enhances Oil Biodegradation and Changes ...

    Science.gov (United States)

    While COREXIT 9500 is widely applied after oil spills for its reported dispersing activity, there is still a debate on the effectiveness on enhancing oil biodegradation and its potential toxic effect on microbial communities. To better understand the impact of COREXIT 9500 on the structure and activity levels of hydrocarbon degrading microbial communities, we analyzed next-generation 16S rRNA gene sequencing libraries of hydrocarbon enrichments grown at cryophilic and mesophilic conditions and using both DNA and RNA extracts as sequencing templates. Oil biodegradation patterns in both cryophilic and mesophilic enrichments were consistent with those reported in the literature (i.e., aliphatics were degraded faster than aromatics). A slight increase in biodegradation was observed in the presence of COREXIT at both 25°C and 5°C experiments. Differences in community structure were observed between treatment conditions in the DNA-based libraries. The 25°C consortia was dominated by unclassified members of the Vibrio, Pseudoidiomarina, Marinobacter, Alcanivorax, and Thallassospira species, while the 5°C consortia were dominated by several genera of Flavobacteria, Alcanivorax and Oleispira. With the exception of Vibrio-like species, members of these genera have been linked to hydrocarbon degradation and have been observed after oil spills. Colwellia and Cycloclasticus, known aromatic degraders, was also found in these enrichments. RNA-based sequencing of 25°C

  19. Development of a biodegradable bone cement

    International Nuclear Information System (INIS)

    Yusof Abdullah; Nurhaslinda Ee Abdullah; Wee Pee Chai; Norita Mohd Zain

    2002-01-01

    Biodegradable bone cement is a newly developed bone repair material, which is able to give immediate support to the implant area, and does not obstruct the bone repairing and regeneration process through appropriate biodegradation rate, which is synchronized with the mechanical load it should bear. The purpose of this study is to locally produce biodegradable bone cement using HA as absorbable filler. The cement is composed of an absorbable filler and unsaturated polyester for 100% degradation. Cross-linking effect is achieved through the action of poly (vinyl pyrrol lidone) (PVP) and an initiator. On the other hand, PPF was synthesized using direct esterification method. Characteristics of the bone cement were studied; these included the curing time, cross-linking effect and curing temperature. The products were characterized using X-Ray diffraction (XRD) to perform phase analysis and Scanning Electrons Microscopes to determine the morphology. The physical and mechanical properties of the bone cement were also investigated. The biocompatibility of the bone cement was tested using simulated body physiological solution. (Author)

  20. HIV/AIDS and Alcohol

    Science.gov (United States)

    Skip to main content National Institute on Alcohol Abuse and Alcoholism (NIAAA) Main Menu Search Search form Search Alcohol & Your Health Overview of Alcohol Consumption Alcohol's Effects on the Body Alcohol ...

  1. Biodegradation of hydrocarbons exploiting spent substrate from ...

    African Journals Online (AJOL)

    SAM

    2014-08-13

    Aug 13, 2014 ... Key words: Bioremediation, diesel, laccase, veratryl alcohol oxidase, Pleurotus ostreatus. ... Abbreviations: Lac, Laccases; MnP, Manganese peroxidases; VP, versatile peroxidases; VAO, veratryl alcohol oxidases; SMS, ..... Hacia un desarrollo sostenible del sistema de producción-consumo de los hongos ...

  2. Best conditions for biodegradation of diesel oil by chemometric tools

    OpenAIRE

    Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Héberger, Károly; Kemény, Sándor; Olszanowski, Andrzej; Voelkel, Adam

    2014-01-01

    Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences). These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positiv...

  3. Equilibrium surface tension and the interaction energy of DMSO with tert-butyl alcohol or iso-amyl alcohol at various temperatures

    International Nuclear Information System (INIS)

    Bagheri, Ahmad; Moradian, Zohreh

    2014-01-01

    Highlights: • Surface tension of non-ideal binary systems of alcohol/DMSO determined. • The surface tension data of binary mixtures were correlated with five equations. • The interaction energy values were calculated by using LWW model. • The U 12 value shows different behavior for two systems with increasing temperature. - Abstract: Surface tension of binary mixtures of tert-butyl alcohol (TBA) and iso-amyl alcohol (IAA) with DMSO (dimethyl sulfoxide) were measured over the entire concentration range at pressure of 82.5 kPa at temperatures between (298.15 and 328.15) K. Correlating the surface tension and surface tension deviation of the above mentioned binary systems was performed with empirical and thermodynamic based models. The average relative error obtained from the comparison of experimental and calculated surface tension values for the two binary systems with five models at various temperatures is less than 2%. The effect of temperature on the interaction energy values in binary mixtures has been used to obtain information about solute structural effects on DMSO. Also, the experimental data were used to evaluate the nature and type of intermolecular interactions in binary mixtures

  4. Biodegradation of flax fiber reinforced poly lactic acid

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available Woven and nonwoven flax fiber reinforced poly lactic acid (PLA biocomposites were prepared with amphiphilic additives as accelerator for biodegradation. The prepared composites were buried in farmland soil for biodegradability studies. Loss in weight of the biodegraded composite samples was determined at different time intervals. The surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM. Results indicated that in presence of mandelic acid, the composites showed accelerated biodegradation with 20–25% loss in weight after 50–60 days. On the other hand, in presence of dicumyl peroxide (as additive, biodegradation of the composites was relatively slow as confirmed by only 5–10% loss in weight even after 80–90 days. This was further confirmed by surface morphology of the biodegraded composites. We have attempted to show that depending on the end uses, we can add different amphiphilic additives for delayed or accelerated biodegradability. This work gives us the idea of biodegradation of materials from natural fiber reinforced PLA composites when discarded carelessly in the environment instead of proper waste disposal site.

  5. Critical evaluation of biodegradable polymers used in nanodrugs

    Science.gov (United States)

    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

  6. Critical evaluation of biodegradable polymers used in nanodrugs.

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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.

  8. Biodegradation of endosulfan by mixed bacteria culture strains of ...

    African Journals Online (AJOL)

    Biodegradation of endosulfan by mixed bacteria culture strains of Pseudomonas aeruginosa and Staphylococcus aureus. Nsidibeabasi Calvin Nwokem, Calvin Onyedika Nwokem, Casmir Emmanuel Gimba, Beatrice Nkiruka Iwuala ...

  9. High barrier multilayer packaging by the coextrusion method: The effect of nanocomposites and biodegradable polymers on flexible film properties

    Science.gov (United States)

    Thellen, Christopher T.

    The objective of this research was to investigate the use of nanocomposite and multilayer co-extrusion technologies for the development of high gas barrier packaging that is more environmentally friendly than many current packaging system. Co-extruded bio-based and biodegradable polymers that could be composted in a municipal landfill were one direction that this research was aimed. Down-gauging of high performance barrier films using nanocomposite technology and co-extrusion was also investigated in order to reduce the amount of solid waste being generated by the packaging. Although the research is focused on military ration packaging, the technologies could easily be introduced into the commercial flexible packaging market. Multilayer packaging consisting of poly(m-xylylene adipamide) nanocomposite layers along with adhesive and tie layers was co-extruded using both laboratory and pilot-scale film extrusion equipment. Co-extrusion of biodegradable polyhydroxyalkanoates (PHA) along with polyvinyl alcohol (PVOH) and tie layers was also accomplished using similar co-extrusion technology. All multilayer films were characterized for gas barrier, mechanical, and thermal properties. The biodegradability of the PVOH and PHA materials in a marine environment was also investigated. The research has shown that co-extrusion of these materials is possible at a research and pilot level. The use of nanocomposite poly(m-xylylene adipamide) was effective in down-gauging the un-filled barrier film to thinner structures. Bio-based PHA/PVOH films required the use of a malefic anhydride grafted PHA tie layer to improve layer to layer adhesion in the structure to avoid delamination. The PHA polymer demonstrated a high rate of biodegradability/mineralization in the marine environment while the rate of biodegradation of the PVOH polymer was slower.

  10. Breath alcohol test (image)

    Science.gov (United States)

    The breath alcohol test measures the amount of alcohol in the blood by testing exhaled air. The test is performed by blowing ... breath machine 15 minutes after alcohol consumption. The test determines how much alcohol it takes to raise the blood-alcohol level ...

  11. Alcohol and Cirrhosis

    Science.gov (United States)

    ... Enter ZIP code here Enter ZIP code here Alcohol and Cirrhosis for Veterans and the Public Alcohol and cirrhosis Alcohol and the Liver Cirrhosis is ... liver to a liver with cirrhosis. How does alcohol affect cirrhosis? Alcohol increases the damage done to ...

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

    Science.gov (United States)

    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.

  13. Preparation of new biodegradable materials by grafting of polycarprolactone onto starch and their biodegradability studies

    International Nuclear Information System (INIS)

    Najemi, L.; Zerroukhi, A.; Jeanmaire, T.; Raihane, M.; Chamkh, F.; Qatibi, A.; Bennisse, R.

    2009-01-01

    The starch is a natural polymer which has the advantage of being biodegradable, renewable in quantity unlimited at very accessible prices. However its poor mechanical properties, depending on its hydrophobic character, and also its absorption of water restrict is applicability considerable especially for packing. (Author)

  14. Biodegradation kinetics for pesticide exposure assessment.

    Science.gov (United States)

    Wolt, J D; Nelson, H P; Cleveland, C B; van Wesenbeeck, I J

    2001-01-01

    Understanding pesticide risks requires characterizing pesticide exposure within the environment in a manner that can be broadly generalized across widely varied conditions of use. The coupled processes of sorption and soil degradation are especially important for understanding the potential environmental exposure of pesticides. The data obtained from degradation studies are inherently variable and, when limited in extent, lend uncertainty to exposure characterization and risk assessment. Pesticide decline in soils reflects dynamically coupled processes of sorption and degradation that add complexity to the treatment of soil biodegradation data from a kinetic perspective. Additional complexity arises from study design limitations that may not fully account for the decline in microbial activity of test systems, or that may be inadequate for considerations of all potential dissipation routes for a given pesticide. Accordingly, kinetic treatment of data must accommodate a variety of differing approaches starting with very simple assumptions as to reaction dynamics and extending to more involved treatments if warranted by the available experimental data. Selection of the appropriate kinetic model to describe pesticide degradation should rely on statistical evaluation of the data fit to ensure that the models used are not overparameterized. Recognizing the effects of experimental conditions and methods for kinetic treatment of degradation data is critical for making appropriate comparisons among pesticide biodegradation data sets. Assessment of variability in soil half-life among soils is uncertain because for many pesticides the data on soil degradation rate are limited to one or two soils. Reasonable upper-bound estimates of soil half-life are necessary in risk assessment so that estimated environmental concentrations can be developed from exposure models. Thus, an understanding of the variable and uncertain distribution of soil half-lives in the environment is

  15. Development of aliphatic biodegradable photoluminescent polymers.

    Science.gov (United States)

    Yang, Jian; Zhang, Yi; Gautam, Santosh; Liu, Li; Dey, Jagannath; Chen, Wei; Mason, Ralph P; Serrano, Carlos A; Schug, Kevin A; Tang, Liping

    2009-06-23

    None of the current biodegradable polymers can function as both implant materials and fluorescent imaging probes. The objective of this study was to develop aliphatic biodegradable photoluminescent polymers (BPLPs) and their associated cross-linked variants (CBPLPs) for biomedical applications. BPLPs are degradable oligomers synthesized from biocompatible monomers including citric acid, aliphatic diols, and various amino acids via a convenient and cost-effective polycondensation reaction. BPLPs can be further cross-linked into elastomeric cross-linked polymers, CBPLPs. We have shown representatively that BPLP-cysteine (BPLP-Cys) and BPLP-serine (BPLP-Ser) offer advantages over the traditional fluorescent organic dyes and quantum dots because of their preliminarily demonstrated cytocompatibility in vitro, minimal chronic inflammatory responses in vivo, controlled degradability and high quantum yields (up to 62.33%), tunable fluorescence emission (up to 725 nm), and photostability. The tensile strength of CBPLP-Cys film ranged from 3.25 +/- 0.13 MPa to 6.5 +/- 0.8 MPa and the initial Modulus was in a range of 3.34 +/- 0.15 MPa to 7.02 +/- 1.40 MPa. Elastic CBPLP-Cys could be elongated up to 240 +/- 36%. The compressive modulus of BPLP-Cys (0.6) (1:1:0.6 OD:CA:Cys) porous scaffold was 39.60 +/- 5.90 KPa confirming the soft nature of the scaffolds. BPLPs also possess great processability for micro/nano-fabrication. We demonstrate the feasibility of using BPLP-Ser nanoparticles ("biodegradable quantum dots") for in vitro cellular labeling and noninvasive in vivo imaging of tissue engineering scaffolds. The development of BPLPs and CBPLPs represents a new direction in developing fluorescent biomaterials and could impact tissue engineering, drug delivery, bioimaging.

  16. Biodegradable Poly(polyol sebacate) Polymers

    OpenAIRE

    Bruggeman, Joost P.; de Bruin, Berend-Jan; Bettinger, Christopher J.; Langer, Robert

    2008-01-01

    We have developed a family of synthetic biodegradable polymers that are composed of structural units endogenous to the human metabolism, designated poly(polyol sebacates) (PPS) polymers. Material properties of PPS polymers can be tuned by altering the polyol monomer and reacting stiochiometric ratio of sebacic acid. These thermoset networks exhibited tensile Young’s moduli ranging from 0.37 ± 0.08 to 378 ± 33 MPa with maximum elongations at break from 10.90 ± 1.37 to 205.16 ± 55.76%, and glas...

  17. Development of biodegradable fungicide by radiation

    International Nuclear Information System (INIS)

    Lee, Young Jeun; Kim, Dong Sub

    2010-01-01

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Sixteen antifungal microbes were isolated and 4 antifungal activity enhanced mutants were induced by using radiation. P. lentimorbus WJ5a17 had 41% higher antifungal activity than the wild type. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified

  18. Development of biodegradable fungicide by radiation

    International Nuclear Information System (INIS)

    Lee, Young Keun; Kim, Dong Sub

    2011-01-01

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified. Microbial pesticide were manufactured in combination of various additives. Antiphytopathogenic effects were proven by pot experiment and It was promising to prevent pepper, Chinese cabbage and radish from anthrax, phytophthora and root rot

  19. Lipase biocatalysis for useful biodegradable products

    Energy Technology Data Exchange (ETDEWEB)

    Linko, Y.Y.; Wang, Zhuo Lin; Uosukainen, E.; Seppaelae, J. [Helsinki Univ. of Technology, Espoo (Finland); Laemsae, M. [Raisio Group Oil Milling Industry, Raisio (Finland)

    1996-12-31

    It was shown that lipases can be used as biocatalysts in the production of useful biodegradable compounds such as 1-butyl oleate by direct esterification of butanol and oleic acid to decrease viscosity of biodiesel in winter use. By enzymic transesterification, a mixture of 2-ethyl-1-hexyl esters from rapeseed oil fatty acids can be obtained in good yields for use as a solvent, and of trimethylolpropane esters for use as a lubricant. Finally, it was demonstrated that polyesters with a mass average molar mass in excess of 75,000 g mol{sup -}1 can be obtained by esterification or transesterification by using lipase as biocatalyst. (author) (3 refs.)

  20. Biodegradation of polyurethanes; Polyurethane no biseibutsu bunkai

    Energy Technology Data Exchange (ETDEWEB)

    Kinpara, N.; Ando, M.; Ohira, Z. [Suzuki Motor Corp., Shizuoka (Japan); Nakajima, T.; Nakahara, T. [University of Tsukuba, Tsukuba (Japan)

    1997-10-01

    Different types of Polyurethane (PUR) are used for various industrial products and are used in increasing quantities every year. We experimented with biodegradation of PURs to dispose of industrial wastes. 2 strains of fungi and 1 strain of bacteria which were seemed to have the ability to degrade PURs well were isolated from various soils and waste water. These strains could degrade ester-type PUR and PUR made from a mixture of ester and ether. However, these strains could not degrade ether-type PUR. From Scanning Electron Microscopy observation, it is suggested that the microbial degradation proceeded in at least 2 patterns. 4 refs., 8 figs., 2 tabs.

  1. Development of biodegradable fungicide by radiation

    International Nuclear Information System (INIS)

    Lee, Youngkeun; Kim, Dongsub

    2012-03-01

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified. Microbial pesticide were manufactured in combination of various additives. Antiphytopathogenic effects were proven by field test and it was promising to prevent Chinese cabbage and radish from phytophthora and root rot

  2. Development of biodegradable fungicide by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Keun; Kim, Dong Sub [KAERI, Daejeon (Korea, Republic of)

    2011-01-15

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified. Microbial pesticide were manufactured in combination of various additives. Antiphytopathogenic effects were proven by pot experiment and It was promising to prevent pepper, Chinese cabbage and radish from anthrax, phytophthora and root rot

  3. Development of biodegradable fungicide by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youngkeun; Kim, Dongsub

    2012-03-15

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified. Microbial pesticide were manufactured in combination of various additives. Antiphytopathogenic effects were proven by field test and it was promising to prevent Chinese cabbage and radish from phytophthora and root rot.

  4. Hydrocarbons biodegradation in unsaturated porous medium; Biodegradation des hydrocarbures en milieu poreux insature

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, C

    2007-12-15

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

  5. Alcohol Use Disorders

    Science.gov (United States)

    ... In this Section Genetics of Alcohol Use Disorder Alcohol Use Disorder Problem drinking that becomes severe is given the medical diagnosis of “alcohol use disorder” or AUD. AUD is a chronic relapsing brain ...

  6. Alcohol Use Screening

    Science.gov (United States)

    ... Depression Screening Substance Abuse Screening Alcohol Use Screening Alcohol Use Screening (AUDIT-C) - Instructions The following questions ... this tool, there is also text-only version . Alcohol Use Screening (AUDIT-C) - Manual Instructions The following ...

  7. Biodegradation performance of environmentally-friendly insulating oil

    Science.gov (United States)

    Yang, Jun; He, Yan; Cai, Shengwei; Chen, Cheng; Wen, Gang; Wang, Feipeng; Fan, Fan; Wan, Chunxiang; Wu, Liya; Liu, Ruitong

    2018-02-01

    In this paper, biodegradation performance of rapeseed insulating oil (RDB) and FR3 insulating oil (FR3) was studied by means of ready biodegradation method which was performed with Organization for Economic Co-operation and Development (OECD) 301B. For comparison, the biodegradation behaviour of 25# mineral insulating oil was also characterized with the same method. The testing results shown that the biodegradation degree of rapeseed insulating oil, FR3 insulating oil and 25# mineral insulating oil was 95.8%, 98.9% and 38.4% respectively. Following the “new chemical risk assessment guidelines” (HJ/T 154 - 2004), which illustrates the methods used to identify and assess the process safety hazards inherent. The guidelines can draw that the two vegetable insulating oils, i.e. rapeseed insulating oil and FR3 insulating oil are easily biodegradable. Therefore, the both can be classified as environmentally-friendly insulating oil. As expected, 25# mineral insulating oil is hardly biodegradable. The main reason is that 25# mineral insulating oil consists of isoalkanes, cyclanes and a few arenes, which has few unsaturated bonds. Biodegradation of rapeseed insulating oil and FR3 insulating oil also remain some difference. Biodegradation mechanism of vegetable insulating oil was revealed from the perspective of hydrolysis kinetics.

  8. Cellulose sulphuric acid as a biodegradable catalyst for conversion ...

    Indian Academy of Sciences (India)

    Cellulose sulphuric acid as a biodegradable catalyst for conversion of aryl amines into azides at room temperature under mild conditions. Firouzeh Nesmati Ali Elhampour. Volume 124 Issue 4 July 2012 ... Keywords. Cellulose sulphuric acid; aryl azides; diazotization; biodegradable. ... Supplementary Material. supp18.pdf ...

  9. Advances in Biodegradation of Multiple Volatile Organic Compounds

    Science.gov (United States)

    Zhang, M.; Yoshikawa, M.

    2017-12-01

    Bioremediation of soil and groundwater containing multiple contaminants remains a challenge in environmental science and engineering because complete biodegradation of all components is necessary but very difficult to accomplish in practice. This presentation provides a brief overview on advances in biodegradation of multiple volatile organic compounds (VOCs) including chlorinated ethylenes, benzene, toluene and dichloromethane (DCM). Case studies on aerobic biodegradation of benzene, toluene and DCM, and integrated anaerobic-aerobic biodegradation of 7 contaminants, specifically, tetrachloroethylene (PCE), trichloroethylene (TCE), cis-dichloroethylene (cis-DCE), vinyl chloride (VC), DCM, benzene and toluene will be provided. Recent findings based on systematic laboratory experiments indicated that aerobic toluene degradation can be enhanced by co-existence of benzene. Propioniferax, not a known benzene, toluene and DCM degrader can be a key microorganism that involves in biodegradation when the three contaminants co-exist. Integrated anaerobic-aerobic biodegradation is capable of completely degrading the seven VOCs with initial concentrations less than 30 mg/L. Dehalococcoides sp., generally considered sensitive to oxygen, can survive aerobic conditions for at least 28 days, and can be activated during the subsequent anaerobic biodegradation. This presentation may provide a systematic information about biodegradation of multiple VOCs, and a scientific basis for the complete bioremediation of multiple contaminants in situ.

  10. Methods for Evaluating the Biodegradability of Environmentally Degradable Polymers

    NARCIS (Netherlands)

    Zee, van der M.

    2014-01-01

    This chapter presents an overview of the current knowledge on experimental methods for monitoring the biodegradability of polymeric materials. The focus is, in particular, on the biodegradation of materials under environmental conditions. Examples of in vivo degradation of polymers used in

  11. Studies on the biodegradation of natural and synthetic polyethylene ...

    African Journals Online (AJOL)

    Michael Horsfall

    performed for the purpose of biodegradation. The natural or biodegradable polyethylene used in the study was disposable plastic bags containing 6% vegetable starch. The initial and final dry weights of plastic bags before and after incubation in the culture medium were compared and the percentage of degradation was ...

  12. Nanocomposites with biodegradable polymers synthesis properties and future perspectives

    CERN Document Server

    2011-01-01

    Polymers are used in practically every facet of daily life. Most polymers come from fossil fuels and are not biodegradable, causing long-term environmental hazards. Biodegradable polymers provide an alternative class of materials. Composites of such polymers have high potential within a wide spectrum of applications.

  13. Biodegradable elastomers for biomedical applications and regenerative medicine

    NARCIS (Netherlands)

    Bat, E.; Zhang Zheng, Z.Z.; Feijen, Jan; Grijpma, Dirk W.; Poot, Andreas A.

    2014-01-01

    Synthetic biodegradable polymers are of great value for the preparation of implants that are required to reside only temporarily in the body. The use of biodegradable polymers obviates the need for a second surgery to remove the implant, which is the case when a nondegradable implant is used. After

  14. Microbial biodegradable potato starch based low density polyethylene

    African Journals Online (AJOL)

    Plastic materials remain in the nature for decades. Slow degradation of plastics in the environment caused a public trend to biodegradable polymers. The aim of this research was to produce the microbial biodegradable low density polyethylene with potato starch. Degradation of potato starch based low density polyethylene ...

  15. Biodegradative activities of some gram- negative bacilli isolated ...

    African Journals Online (AJOL)

    Their biodegradative activities were studied and confirmed by the change in the Total Petroleum Hydrocarbon (TPH) using gravimetric method. The biodegradative abilities of the isolates were compared by measuring the optical densities, total viable count, pH and emulsification activity. The results showed that the ...

  16. Effect of adsorption and aqueous speciation on nitrilotriacetate biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Girvin, D.C.; Bolton, H. Jr. [Pacific Northwest Lab., Richland, WA (United States)

    1995-12-01

    Nitrilotriacetic acid (NTA) forms strong water soluable complexes with a wide range of radionuclide and metal ions. Knowledge of sorption-biodegradation interactions is essential to predict the environmental transport of radionuclide-NTA complexes. Biodegradation of NTA and cobalt-NTA by Chelatobacter heintzii was investigated.

  17. Biodegradation of phenol | Nair | African Journal of Biotechnology

    African Journals Online (AJOL)

    Biodegradation of phenol. CI Nair, K Jayachandran, S Shashidhar. Abstract. The use of microbial catalysts in the biodegradation of organic compounds has advanced significantly during the past three decades. It has been found that large numbers of microbes co-exist in almost all natural environments, particularly in soils.

  18. Biodegradation of Lagoma crude oil using pig dung | Yakubu ...

    African Journals Online (AJOL)

    Pig dung bacteria were isolated and screened for crude oil degrading capabilities. The pig dung was also investigated for enhancement of crude oil biodegradation. Addition of chicken manure to oil polluted soil (at 10% (v/w) pollution level) stimulated the biodegradation of lagoma crude oil used in the present study.

  19. Biodegradation of clofibric acid and identification of its metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, R. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); ESTS-IPS, Escola Superior de Tecnologia de Setubal do Instituto Politecnico de Setubal, Rua Vale de Chaves, Campus do IPS, Estefanilha, 2910-761 Setubal (Portugal); Oehmen, A. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Carvalho, G. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Instituto de Biologia Experimental e Tecnologica (IBET), Av. da Republica (EAN), 2784-505 Oeiras (Portugal); Noronha, J.P. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Reis, M.A.M., E-mail: amr@fct.unl.pt [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2012-11-30

    Graphical abstract: Metabolites produced during clofibric acid biodegradation. Highlights: Black-Right-Pointing-Pointer Clofibric acid is biodegradable. Black-Right-Pointing-Pointer Mainly heterotrophic bacteria degraded the clofibric acid. Black-Right-Pointing-Pointer Metabolites of clofibric acid biodegradation were identified. Black-Right-Pointing-Pointer The metabolic pathway of clofibric acid biodegradation is proposed. - Abstract: Clofibric acid (CLF) is the pharmaceutically active metabolite of lipid regulators clofibrate, etofibrate and etofyllinclofibrate, and it is considered both environmentally persistent and refractory. This work studied the biotransformation of CLF in aerobic sequencing batch reactors (SBRs) with mixed microbial cultures, monitoring the efficiency of biotransformation of CLF and the production of metabolites. The maximum removal achieved was 51% biodegradation (initial CLF concentration = 2 mg L{sup -1}), where adsorption and abiotic removal mechanisms were shown to be negligible, showing that CLF is indeed biodegradable. Tests showed that the observed CLF biodegradation was mainly carried out by heterotrophic bacteria. Three main metabolites were identified, including {alpha}-hydroxyisobutyric acid, lactic acid and 4-chlorophenol. The latter is known to exhibit higher toxicity than the parent compound, but it did not accumulate in the SBRs. {alpha}-Hydroxyisobutyric acid and lactic acid accumulated for a period, where nitrite accumulation may have been responsible for inhibiting their degradation. A metabolic pathway for the biodegradation of CLF is proposed in this study.

  20. Biodegradable elastomers for biomedical applications and regenerative medicine

    NARCIS (Netherlands)

    Bat, Erhan; Zhang, Zheng; Feijen, Jan; Grijpma, Dirk W.; Poot, Andre A.

    Synthetic biodegradable polymers are of great value for the preparation of implants that are required to reside only temporarily in the body. The use of biodegradable polymers obviates the need for a second surgery to remove the implant, which is the case when a nondegradable implant is used. After

  1. Torsion strenght of biodegradable and titanium screws: a comparison.

    NARCIS (Netherlands)

    Buijs, Gerrit J.; van der Houwen, Eduard B.; Stegenga, Boudewijn; Bos, Rudolf R.M.; Verkerke, Gijsbertus Jacob

    2007-01-01

    Purpose: To determine 1) the differences in maximum torque between 7 biodegradable and 2 titanium screw systems, and 2) the differences of maximum torque between “hand tight” and break of the biodegradable and the titanium osteofixation screw systems. Materials and Methods: Four oral and

  2. Biodegradability of tannin-containing wastewater from leather industry.

    Science.gov (United States)

    He, Qiang; Yao, Kai; Sun, Danhong; Shi, Bi

    2007-08-01

    Tannins occur commonly in the wastewaters from forestry, plant medicine, paper and leather industries. The treatment of this kind of wastewaters, including settling and biodegradation, is usually difficult because tannins are highly soluble in water and would inhibit the growth of microorganisms in activated sludge. The objective of this study is to investigate biodegradability of tannin-containing wastewaters, so as to characterize the pollution properties of such wastewaters and provide a reference for their biological treatment in wastewater treatment plants. The research was typified by using the wastewater collected from vegetable tanning process in leather industry. A model was developed to describe the activated sludge process, and the biodegradation kinetics of vegetable tanning wastewater (VET wastewater) was studied. It was found that the biodegradability of tannin-containing wastewater varies heavily with the content of tannins in wastewater. The biodegradation of VET wastewater with tannin content around 4,900 mg/l occurred inefficiently due to the inhibition of tannins to the activated sludge process, and only 34.7% of biodegradation extent was reached in 14 days of incubation. The optimal biodegradability of VET wastewater was observed when its tannin content was diluted to 490 mg/l, where the COD and tannin removals reached 51.3% and 45.1% respectively in 6 days. Hence, it is suggested that a proper control of tannin content is necessary to achieve an effective biodegradation of tannin-containing wastewaters in wastewater treatment plants.

  3. Sociobiology of biodegradation and the role of predatory protozoa in ...

    Indian Academy of Sciences (India)

    PRAKASH KUMAR

    A variety of protozoa are associated with different biodegrading microbial communities. Some of these protozoa have been shown to produce extracellular enzymes and hence play a direct role in biodegradation (Jouany and. Martin 1997). However, a large number of protozoal species play only a predatory role and mainly ...

  4. Fungal biodegradation of plantain peel for broiler finisher feeding: In ...

    African Journals Online (AJOL)

    ... protein, cholesterol and glucose were significantly (P<0.05) affected by the treatments. Fungal biodegradation of PPL using A.niger has the potential of enhancing feed intake, nutrient digestibility and the body weight gain of broiler finisher. Keywords: Aspergillus niger, biodegradation, nutrient enhancement and broilers.

  5. Polímeros biodegradables. Importancia y potenciales aplicaciones

    OpenAIRE

    Labeaga Viteri, Aitziber

    2018-01-01

    Un polímero biodegradable es aquel que puede ser degradado completamente por el medio ambiente, reduciendo así el impacto ambiental que estos materiales producen. Por lo tanto, de acuerdo con esta definición, cuando un envase plástico biodegradable es

  6. Biodegradable hollow fibres for the controlled release of drugs

    NARCIS (Netherlands)

    Schakenraad, J.M.; Oosterbaan, J.A.; Nieuwenhuis, P.; Molenaar, I.; Olijslager, J.; Potman, W.; Eenink, M.J.D.; Feijen, Jan

    1988-01-01

    Biodegradable hollow fibres of poly-l-lactic acid (PLLA) filled with a suspension of the contraceptive hormone levonorgestrel in castor oil were implanted subcutaneously in rats to study the rate of drug release, rate of biodegradation and tissue reaction caused by the implant. The in vivo drug

  7. Biodegradation of flax fiber reinforced poly lactic acid

    CSIR Research Space (South Africa)

    Kumar, R

    2010-07-01

    Full Text Available , the composites showed accelerated biodegradation with 20–25% loss in weight after 50–60 days. On the other hand, in presence of dicumyl peroxide (as additive), biodegradation of the composites was relatively slow as confirmed by only 5–10% loss in weight even...

  8. Activated Sludge Biodegradation of 12 Commercial Phthalate Esters

    OpenAIRE

    O'Grady, Dean P.; Howard, Philip H.; Werner, A. Frances

    1985-01-01

    The activated sludge biodegradability of 12 commercial phthalate esters was evaluated in two test systems: (i) a semicontinuous activated sludge test and (ii) an acclimated 19-day die-away procedure. Both procedures demonstrated that phthalate esters are rapidly biodegraded under activated sludge conditions when loss of the parent phthalate ester (primary degradation) is measured.

  9. Development of Biomarkers for Assessing In Situ RDX Biodegradation Potential

    Science.gov (United States)

    2010-02-01

    could be used to identify RDX degraders in mixed culture samples. This information can ultimately be used to assess the potential for bioremediation and... bioremediation potential at RDX contaminated sites. 6 ER1606 –Development of Biomarkers for Assessing In Situ RDX...Microbial populations related to PAH biodegradation in an aged biostimulated creosote -contaminated soil. Biodegradation 20,593-601. Ludwig, W

  10. Advancing Alcohol Biomarkers Research

    OpenAIRE

    Bearer, Cynthia F.; Bailey, Shannon M.; Hoek, Jan B.

    2010-01-01

    Biomarkers to detect past alcohol use and identify alcohol-related diseases have long been pursued as important tools for research into alcohol use disorders as well as for clinical and treatment applications and other settings. The National Institute on Alcohol Abuse and Alcoholism (NIAAA) sponsored a workshop titled “Workshop on Biomarkers for Alcohol-Induced Disorders” in June 2008. The intent of this workshop was to review and discuss recent progress in the development and implementation ...

  11. Preparation of biodegradable porous poly(butylene succinate microspheres

    Directory of Open Access Journals (Sweden)

    Pepić Dragana

    2008-01-01

    Full Text Available The aim of this study was to determine the optimal conditions for the fabrication of porous microspheres based on poly(butylene succinate, PBS. The biodegradable non-porous PBS microspheres were prepared by the oil-in-water (o/w emulsion solvent evaporation method using poly(vinyl alcohol, PVA, as the surfactant. Fabrication conditions, such as stirring rate, organic/aqueous ratio, PBS concentration and surfactant (PVA concentration, which have an important influence on both the particle size and the morphology of the microspheres, were varied. Scanning electron microscopy, SEM, observations confirmed the size, size distribution and surface morphology of the microspheres. The optimal conditions for the preparation of the non-porous microspheres were found to be: concentration the PBS solution, 10 mass%; PVA concentration, 1 mass%; the organic/ aqueous ratio CHCl3/H2O = 1/20 and stirring rate 800 rpm. Porous PBS microspheres were fabricated under the optimal conditions using various amounts of hexane and poly(ethylene oxide, PEO, as porogens. The influence of the amount of porogen on the pore size and the particle size was investigated using SEM and the apparent density. The microspheres exhibited various porosities and the pore sizes. The average particle size of the microspheres with PEO as the porogen was from 100 to 122μm and that of the microspheres with hexane as the porogen was from 87 to 97μm. The apparent density of the porous microspheres with PEO as the porogen, from 0.16 to 0.23 g/cm3, was much smaller than the non-porous microspheres, 0.40 g/cm3. In the in vitro degradation experiments, the porous microspheres were incubated in phosphate buffer solution (pH 7 at 37°C. After incubating for one month, the microspheres showed significant extent of the hydrolytic degradation of the porous PBS microspheres.

  12. Evaluation of Artificial Intelligence Based Models for Chemical Biodegradability Prediction

    Directory of Open Access Journals (Sweden)

    Aleksandar Sabljic

    2004-12-01

    Full Text Available 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.

  13. Best conditions for biodegradation of diesel oil by chemometric tools

    Directory of Open Access Journals (Sweden)

    Ewa Kaczorek

    2014-01-01

    Full Text Available Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences. These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positive effect of rhamnolipids on hydrocarbon biodegradation was observed. However, rhamnolipids addition did not always have a positive influence on the biodegradation process (e.g. in case of yeast consortia with Stenotrophomonas maltophila KR7. Moreover, particular differences in the degradation pattern were observed for lower and higher alkanes than in the case with C22. Normally, the best conditions for "lower" alkanes are Aeromonas hydrophila KR4 + emulsifier independently from yeasts and e.g. Pseudomonas stutzeri KR7 for C24 alkane.

  14. Best conditions for biodegradation of diesel oil by chemometric tools

    Science.gov (United States)

    Kaczorek, Ewa; Bielicka-Daszkiewicz, Katarzyna; Héberger, Károly; Kemény, Sándor; Olszanowski, Andrzej; Voelkel, Adam

    2014-01-01

    Diesel oil biodegradation by different bacteria-yeast-rhamnolipids consortia was tested. Chromatographic analysis of post-biodegradation residue was completed with chemometric tools (ANOVA, and a novel ranking procedure based on the sum of ranking differences). These tools were used in the selection of the most effective systems. The best results of aliphatic fractions of diesel oil biodegradation were observed for a yeast consortia with Aeromonas hydrophila KR4. For these systems the positive effect of rhamnolipids on hydrocarbon biodegradation was observed. However, rhamnolipids addition did not always have a positive influence on the biodegradation process (e.g. in case of yeast consortia with Stenotrophomonas maltophila KR7). Moreover, particular differences in the degradation pattern were observed for lower and higher alkanes than in the case with C22. Normally, the best conditions for “lower” alkanes are Aeromonas hydrophila KR4 + emulsifier independently from yeasts and e.g. Pseudomonas stutzeri KR7 for C24 alkane. PMID:24948922

  15. Alcohol Alert: Link Between Stress and Alcohol

    Science.gov (United States)

    ... PTSD and alcohol dependence. 25 Such interventions include cognitive–behavioral therapies, such as exposure-based therapies, in which the ... et al. Resilience to meet the challenge of addiction: Psychobiology and clinical considerations. Alcohol Research: Current Reviews ...

  16. Oxidation and biodegradation of polyethylene films containing pro-oxidantadditives: Synergistic effects of sunlight exposure, thermal aging and fungal biodegradation

    Science.gov (United States)

    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...

  17. A REVIEW ON BIODEGRADABLE STARCH BASED FILM

    Directory of Open Access Journals (Sweden)

    Hooman Molavi

    2015-04-01

    Full Text Available In recent years, biodegradable edible films have become very important in research related to food, due to their compatibility with the environment and their use in the food packaging industry. Various sources can be used in the production of biopolymers as biodegradable films that include polysaccharides, proteins and lipids. Among the various polysaccharides, starch due to its low price and its abundance in nature is of significant importance. Several factors affect the properties of starch films; such as the source which starch is obtained from, as well as the ratio of constituents of the starch. Starch films have advantages such as low thickness, flexibility and transparency though; there are some downsides to mention, such as the poor mechanical properties and water vapor permeability. Thus, using starch alone to produce the film will led to restrictions on its use. To improve the mechanical properties of starch films and also increases resistance against humidity, several methods can be used; including the starch modifying techniques such as cross linking of starch and combining starch with other natural polymers. Other methods such as the use of lipid in formulations of films to increase the resistance to moisture are possible, but lipids are susceptible to oxidation. Therefore, new approaches are based on the integration of different biopolymers in food packaging.

  18. Design Considerations for Developing Biodegradable Magnesium Implants

    Science.gov (United States)

    Brar, Harpreet S.; Keselowsky, Benjamin G.; Sarntinoranont, Malisa; Manuel, Michele V.

    The integration of biodegradable and bioabsorbable magnesium implants into the human body is a complex undertaking that faces major challenges. The complexity arises from the fact that biomaterials must meet both engineering and physiological requirements to ensure the desired properties. Historically, efforts have been focused on the behavior of commercial magnesium alloys in biological environments and their resultant effect on cell-mediated processes. Developing causal relationships between alloy chemistry and micro structure, and its effect on cellular behavior can be a difficult and time intensive process. A systems design approach driven by thermodynamics has the power to provide significant contributions in developing the next generation of magnesium alloy implants with controlled degradability, biocompatibility, and optimized mechanical properties, at reduced time and cost. This approach couples experimental research with theory and mechanistic modeling for the accelerated development of materials. The aim of this article is to enumerate this strategy, design considerations and hurdles for developing new magnesium alloys for use as biodegradable implant materials [1].

  19. Polymeric Biodegradable Stent Insertion in the Esophagus

    Directory of Open Access Journals (Sweden)

    Kai Yang

    2016-04-01

    Full Text Available Esophageal stent insertion has been used as a well-accepted and effective alternative to manage and improve the quality of life for patients diagnosed with esophageal diseases and disorders. Current stents are either permanent or temporary and are fabricated from either metal or plastic. The partially covered self-expanding metal stent (SEMS has a firm anchoring effect and prevent stent migration, however, the hyperplastic tissue reaction cause stent restenosis and make it difficult to remove. A fully covered SEMS and self-expanding plastic stent (SEPS reduced reactive hyperplasia but has a high migration rate. The main advantage that polymeric biodegradable stents (BDSs have over metal or plastic stents is that removal is not require and reduce the need for repeated stent insertion. But the slightly lower radial force of BDS may be its main shortcoming and a post-implant problem. Thus, strengthening support of BDS is a content of the research in the future. BDSs are often temporarily effective in esophageal stricture to relieve dysphagia. In the future, it can be expect that biodegradable drug-eluting stents (DES will be available to treat benign esophageal stricture, perforations or leaks with additional use as palliative modalities for treating malignant esophageal stricture, as the bridge to surgery or to maintain luminal patency during neoadjuvant chemoradiation.

  20. Synthesis of piroxicam loaded novel electrospun biodegradable nanocomposite scaffolds for periodontal regeneration

    International Nuclear Information System (INIS)

    Farooq, Ariba; Yar, Muhammad; Khan, Abdul Samad; Shahzadi, Lubna; Siddiqi, Saadat Anwar; Mahmood, Nasir; Rauf, Abdul; Qureshi, Zafar-ul-Ahsan; Manzoor, Faisal; Chaudhry, Aqif Anwar; Rehman, Ihtesham ur

    2015-01-01

    Development of biodegradable composites having the ability to suppress or eliminate the pathogenic micro-biota or modulate the inflammatory response has attracted great interest in order to limit/repair periodontal tissue destruction. The present report includes the development of non-steroidal anti-inflammatory drug encapsulated novel biodegradable chitosan (CS)/poly(vinyl alcohol) (PVA)/hydroxyapatite (HA) electro-spun (e-spun) composite nanofibrous mats and films and study of the effect of heat treatment on fibers and films morphology. It also describes comparative in-vitro drug release profiles from heat treated and control (non-heat treated) nanofibrous mats and films containing varying concentrations of piroxicam (PX). Electrospinning was used to obtain drug loaded ultrafine fibrous mats. The physical/chemical interactions were evaluated by Fourier Transform Infrared (FT-IR) spectroscopy. The morphology, structure and pore size of the materials were investigated by scanning electron microscopy (SEM). The thermal behavior of the materials was investigated by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Control (not heat treated) and heat treated e-spun fibers mats and films were tested for in vitro drug release studies at physiological pH 7.4 and initially, as per requirement burst release patterns were observed from both fibers and films and later sustained release profiles were noted. In vitro cytocompatibility was performed using VERO cell line of epithelial cells and all the synthesized materials were found to be non-cytotoxic. The current observations suggested that these materials are potential candidates for periodontal regeneration. - Highlights: • Novel non-steroidal anti-inflammatory drug encapsulated biodegradable electrospun nanocomposite scaffolds were synthesized. • Heat treatment displayed great influence on the morphology of scaffolds. • Fiber diameter was decreased and pore size was increased after heat

  1. Synthesis of piroxicam loaded novel electrospun biodegradable nanocomposite scaffolds for periodontal regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Farooq, Ariba [Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore,54000 (Pakistan); Yar, Muhammad, E-mail: drmyar@ciitlahore.edu.pk [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore,54000 (Pakistan); Khan, Abdul Samad; Shahzadi, Lubna; Siddiqi, Saadat Anwar [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore,54000 (Pakistan); Mahmood, Nasir [Department of Allied Health Sciences and Chemical Pathology, University of Health Sciences, Lahore (Pakistan); Department of Human Genetics and Molecular Biology, University of Health Sciences, Lahore (Pakistan); Rauf, Abdul [Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Qureshi, Zafar-ul-Ahsan [Veterinary Research Institute, Lahore (Pakistan); Manzoor, Faisal; Chaudhry, Aqif Anwar [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore,54000 (Pakistan); Rehman, Ihtesham ur [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore,54000 (Pakistan); Department of Materials Science and Engineering, The Kroto Research Institute, The University of Sheffield, North Campus, Broad Lane, Sheffield S3 7HQ (United Kingdom)

    2015-11-01

    Development of biodegradable composites having the ability to suppress or eliminate the pathogenic micro-biota or modulate the inflammatory response has attracted great interest in order to limit/repair periodontal tissue destruction. The present report includes the development of non-steroidal anti-inflammatory drug encapsulated novel biodegradable chitosan (CS)/poly(vinyl alcohol) (PVA)/hydroxyapatite (HA) electro-spun (e-spun) composite nanofibrous mats and films and study of the effect of heat treatment on fibers and films morphology. It also describes comparative in-vitro drug release profiles from heat treated and control (non-heat treated) nanofibrous mats and films containing varying concentrations of piroxicam (PX). Electrospinning was used to obtain drug loaded ultrafine fibrous mats. The physical/chemical interactions were evaluated by Fourier Transform Infrared (FT-IR) spectroscopy. The morphology, structure and pore size of the materials were investigated by scanning electron microscopy (SEM). The thermal behavior of the materials was investigated by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Control (not heat treated) and heat treated e-spun fibers mats and films were tested for in vitro drug release studies at physiological pH 7.4 and initially, as per requirement burst release patterns were observed from both fibers and films and later sustained release profiles were noted. In vitro cytocompatibility was performed using VERO cell line of epithelial cells and all the synthesized materials were found to be non-cytotoxic. The current observations suggested that these materials are potential candidates for periodontal regeneration. - Highlights: • Novel non-steroidal anti-inflammatory drug encapsulated biodegradable electrospun nanocomposite scaffolds were synthesized. • Heat treatment displayed great influence on the morphology of scaffolds. • Fiber diameter was decreased and pore size was increased after heat

  2. Health risks of alcohol use

    Science.gov (United States)

    Alcoholism - risks; Alcohol abuse - risks; Alcohol dependence - risks; Risky drinking ... Beer, wine, and liquor all contain alcohol. If you are drinking any of these, you are using alcohol. Your drinking patterns may vary, depending on who you are with ...

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

    DEFF Research Database (Denmark)

    Tolstrup, J.S.; Nordestgaard, Børge; Rasmussen, S.

    2008-01-01

    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......, 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...

  4. Novel meloxicam releasing electrospun polymer/ceramic reinforced biodegradable membranes for periodontal regeneration applications

    International Nuclear Information System (INIS)

    Yar, Muhammad; Farooq, Ariba; Shahzadi, Lubna; Khan, Abdul Samad; Mahmood, Nasir; Rauf, Abdul; Chaudhry, Aqif Anwar; Rehman, Ihtesham ur

    2016-01-01

    Periodontal disease is associated with the destruction of periodontal tissues, along with other disorders/problems including inflammation of tissues and severe pain. This paper reports the synthesis of meloxicam (MX) immobilized biodegradable chitosan (CS)/poly(vinyl alcohol) (PVA)/hydroxyapatite (HA) based electrospun (e-spun) fibers and films. Electrospinning was employed to produce drug loaded fibrous mats, whereas films were generated by solvent casting method. In-vitro drug release from materials containing varying concentrations of MX revealed that the scaffolds containing higher amount of drug showed comparatively faster release. During initial first few hours fast release was noted from membranes and films; however after around 5 h sustained release was achieved. The hydrogels showed good swelling property, which is highly desired for soft tissue engineered implants. To investigate the biocompatibility of our synthesized materials, VERO cells (epithelial cells) were selected and cell culture results showed that these all materials were non-cytotoxic and also these cells were very well proliferated on these synthesized scaffolds. These properties along with the anti-inflammatory potential of our fabricated materials suggest their effective utilization in periodontital treatments. - Highlights: • NSAIDs releasing scaffolds for periodontal regeneration applications • Meloxicam immobilized biodegradable nanocomposite electrospun membranes and films • Good swelling properties • Controlled drug release • VERO cells were very well proliferated and synthesized materials were found to be non-cytotoxic.

  5. Mechanical Properties and Biodegradability of the Kenaf/Soy Protein Isolate-PVA Biocomposites

    Directory of Open Access Journals (Sweden)

    Jong Sung Won

    2015-01-01

    Full Text Available The effective utilization of original natural fibers as indispensable components in natural resins for developing novel, low-cost, eco-friendly biocomposites is one of the most rapidly emerging fields of research in fiber-reinforced composite. The objective of this study is to investigate the interfacial adhesion properties, water absorption, biodegradation properties, and mechanical properties of the kenaf/soy protein isolate- (SPI- PVA composite. Experimental results showed that 20 wt% poly (vinyl alcohol (PVA and 8 wt% glutaraldehyde (GA created optimum conditions for the consolidation of the composite. The increase of interfacial shear strength enhanced the composites flexural and tensile strength of the kenaf/SPI-PVA composite. The kenaf/SPI-PVA mechanical properties of the composite also increased with the content of cross-linking agent. Results of the biodegradation test indicated that the degradation time of the composite could be controlled by the cross-linking agent. The degradation rate of the kenaf/SPI-PVA composite with the cross-linking agent was lower than that of the composite without the cross-linking agent.

  6. Anaerobic biodegradation of gasoline oxygenates. Extrapolation of information to multiple sites and redox conditions

    Energy Technology Data Exchange (ETDEWEB)

    Mormile, M.R.; Liu, S.; Suflita, J.M. (Univ. of Oklahoma, Norman, OK (United States))

    1994-09-01

    A series of alcohol, ketone, ester, and ether oxygenates were tested for their susceptibility to anaerobic decay in samples from four chronically contaminated sedimentary environments. The effect of various electron acceptors on oxygenate biodegradation was also evaluated with a single inoculum source. In addition, two acetogenic bacteria were tested for their ability to metabolize selected oxygenate compounds. The susceptibility of the test oxygenates to anaerobic decay could be related to their chemical structure. That is, compounds other than the ethers that possessed primary or secondary substituted carbon atoms were readily degraded under all conditions tested while compounds that had tertiary substituted carbon atoms resisted biodegradation. The ether oxygenates were generally not degraded when incubated with various inocula, regardless of the electron acceptor status. The exceptions included methyl butyl ether, which was depleted in both sulfate-reducing and methanogenic incubations, and the partial transformation of methyl tert-butyl ether to tert-butanol after a 152-day acclimation period in a single replicate from a river sediment chronically contaminated with fuel. Heat-inactivated control incubations suggested that the latter transformation was biologically catalyzed. 47 refs., 1 fig., 3 tabs.

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

    International Nuclear Information System (INIS)

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

    2013-01-01

    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. - Highlights: ► Development and characterization of PVA/Chitosan biodegradable film ► Lipase immobilization onto PVA/Chitosan film ► PVA/Chitosan/Lipase film for reactor coating ► Olive oil hydrolysis using PVA/Chitosan/Lipase film

  8. Novel meloxicam releasing electrospun polymer/ceramic reinforced biodegradable membranes for periodontal regeneration applications

    Energy Technology Data Exchange (ETDEWEB)

    Yar, Muhammad, E-mail: drmyar@ciitlahore.edu.pk [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Farooq, Ariba [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Shahzadi, Lubna; Khan, Abdul Samad [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Mahmood, Nasir [Department of Allied Health Sciences and Chemical Pathology, Department of Human Genetics and Molecular Biology, University of Health Sciences, Lahore (Pakistan); Rauf, Abdul [Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Chaudhry, Aqif Anwar [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Rehman, Ihtesham ur [Interdisciplinary Research Center in Biomedical Materials, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Materials Science and Engineering, The Kroto Research Institute, The University of Sheffield, North Campus, Broad Lane, Sheffield S3 7HQ (United Kingdom)

    2016-07-01

    Periodontal disease is associated with the destruction of periodontal tissues, along with other disorders/problems including inflammation of tissues and severe pain. This paper reports the synthesis of meloxicam (MX) immobilized biodegradable chitosan (CS)/poly(vinyl alcohol) (PVA)/hydroxyapatite (HA) based electrospun (e-spun) fibers and films. Electrospinning was employed to produce drug loaded fibrous mats, whereas films were generated by solvent casting method. In-vitro drug release from materials containing varying concentrations of MX revealed that the scaffolds containing higher amount of drug showed comparatively faster release. During initial first few hours fast release was noted from membranes and films; however after around 5 h sustained release was achieved. The hydrogels showed good swelling property, which is highly desired for soft tissue engineered implants. To investigate the biocompatibility of our synthesized materials, VERO cells (epithelial cells) were selected and cell culture results showed that these all materials were non-cytotoxic and also these cells were very well proliferated on these synthesized scaffolds. These properties along with the anti-inflammatory potential of our fabricated materials suggest their effective utilization in periodontital treatments. - Highlights: • NSAIDs releasing scaffolds for periodontal regeneration applications • Meloxicam immobilized biodegradable nanocomposite electrospun membranes and films • Good swelling properties • Controlled drug release • VERO cells were very well proliferated and synthesized materials were found to be non-cytotoxic.

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

    Energy Technology Data Exchange (ETDEWEB)

    Batista, Karla A. [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil); Lopes, Flavio Marques [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil); Unidade Universitária de Ciências Exatas e Tecnológicas, Universidade Estadual de Goiás, Anápolis, GO (Brazil); Yamashita, Fabio [Departamento de Tecnologia de Alimentos e Medicamentos, Laboratório de Tecnologia, Universidade Estadual de Londrina, Cx. Postal 6001, CEP 86051-990, Londrina, PR (Brazil); Fernandes, Kátia Flávia, E-mail: katia@icb.ufg.br [Departamento de Bioquímica e Biologia Molecular, Laboratório de Química de Proteínas, Universidade Federal de Goiás, Cx. Postal 131, 74001-970, Goiânia, GO (Brazil)

    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. - Highlights: ► Development and characterization of PVA/Chitosan biodegradable film ► Lipase immobilization onto PVA/Chitosan film ► PVA/Chitosan/Lipase film for reactor coating ► Olive oil hydrolysis using PVA/Chitosan/Lipase film.

  10. Novel pH-sensitive biodegradable polymeric drug delivery systems based on ketal polymers.

    Science.gov (United States)

    Chen, Daquan; Wang, Hongbo

    2014-01-01

    This article reviews the recent developments on novel pH-sensitive ketal-based biodegradable polymeric drug delivery systems. Due to the degradation of ketal derivatives, neutral alcohols and ketones, ketal derivatives can be used to fabricate pH-degradable polymer with pH-degradable ketal linkages in new drug delivery systems by avoiding inflammatory problems. Due to the novelty of ketal polymers, there were few reports about ketal polymers. The review starts with a brief introduction to the pH-sensitive drug delivery system, followed by the structure, preparation and characterization techniques of ketal polymers. Thereafter, the promising applications in various diseases in relation to micro/nano drug carriers based on ketal polymers are summarized and discussed.

  11. Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

    Directory of Open Access Journals (Sweden)

    José Maria Rodrigues da Luz

    Full Text Available 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.

  12. Biodegradation of polyethylene by the thermophilic bacterium Brevibacillus borstelensis.

    Science.gov (United States)

    Hadad, D; Geresh, S; Sivan, A

    2005-01-01

    To select a polyethylene-degrading micro-organism and to study the factors affecting its biodegrading activity. A thermophilic bacterium Brevibaccillus borstelensis strain 707 (isolated from soil) utilized branched low-density polyethylene as the sole carbon source and degraded it. Incubation of polyethylene with B. borstelensis (30 days, 50 degrees C) reduced its gravimetric and molecular weights by 11 and 30% respectively. Brevibaccillus borstelensis also degraded polyethylene in the presence of mannitol. Biodegradation of u.v. photo-oxidized polyethylene increased with increasing irradiation time. Fourier Transform Infra-Red (FTIR) analysis of photo-oxidized polyethylene revealed a reduction in carbonyl groups after incubation with the bacteria. This study demonstrates that polyethylene--considered to be inert--can be biodegraded if the right microbial strain is isolated. Enrichment culture methods were effective for isolating a thermophilic bacterium capable of utilizing polyethylene as the sole carbon and energy source. Maximal biodegradation was obtained in combination with photo-oxidation, which showed that carbonyl residues formed by photo-oxidation play a role in biodegradation. Brevibaccillus borstelensis also degraded the CH2 backbone of nonirradiated polyethylene. Biodegradation of polyethylene by a single bacterial strain contributes to our understanding of the process and the factors affecting polyethylene biodegradation.

  13. Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

    Science.gov (United States)

    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.

  14. Alcoholism and Rural America.

    Science.gov (United States)

    DiNitto, Diana

    1982-01-01

    Describes patterns of problem drinking in rural areas, suggests factors which may influence the comparatively lower rates of alcoholism among rural residents, discusses the types of alcohol treatment available in rural communities, and offers preliminary ideas for applying the alcoholism-reducing factors of rural life to preventing alcoholism in…

  15. Turning to alcohol?

    International Nuclear Information System (INIS)

    Reiboro, S.K.

    1998-01-01

    Brazil is examining whether turning to alcohol could solve its problems. The fuel alcohol producers are lobbying hard for the government to increase the use of alcohol to fuel the country's cars. Not only does using alcohol reduce CO 2 , runs the argument, but the Kyoto agreement might just attract international financing for the project. (author)

  16. Women and Alcohol

    Science.gov (United States)

    ... about 5 percent alcohol content »» 5 ounces of wine with about 12 percent alcohol content »» 1.5 ounces of distilled spirits with about 40 percent alcohol content The percent of pure alcohol varies ... glass of wine, or a single mixed drink could contain much ...

  17. Nurses' Attitudes towards Alcoholics.

    Science.gov (United States)

    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…

  18. Internet Alcohol Marketing and Underage Alcohol Use.

    Science.gov (United States)

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

    2016-02-01

    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. 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. 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. 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. Copyright © 2016 by the American Academy of Pediatrics.

  19. Polydioxanone biodegradable stent placement in a canine urethral model: analysis of inflammatory reaction and biodegradation.

    Science.gov (United States)

    Park, Jung-Hoon; Song, Ho-Young; Shin, Ji Hoon; Kim, Jin Hyoung; Jun, Eun Jung; Cho, Young Chul; Kim, Soo Hwan; Park, Jihong

    2014-08-01

    To investigate the inflammatory reaction and perform quantitative analysis of biodegradation after placement of a polydioxanone (PDO) biodegradable stent in a canine urethral model. PDO biodegradable stents were placed in the proximal and distal urethra of nine male mongrel dogs. The dogs were euthanized 4 weeks (group A; n = 3), 8 weeks (group B; n = 3), or 12 weeks (group C; n = 3) after stent placement. The luminal diameter of the stent-implanted urethra was assessed by follow-up retrograde urethrography, and histologic findings were obtained after the dogs were killed. Stents were removed after euthanasia, and their surface morphology and molecular weight were evaluated. Hematologic examination was performed to evaluate inflammatory reaction. Stent placement was technically successful in all dogs. The average luminal diameter gradually decreased. The average number of epithelial layers (2.93 vs 4.42; P stents were completely decomposed. An experimental study in a canine urethral model has demonstrated acceptable inflammatory reaction with gradually increasing granulation tissue but no luminal obstruction within 12 weeks. Copyright © 2014 SIR. Published by Elsevier Inc. All rights reserved.

  20. Alcohol and Breastfeeding

    DEFF Research Database (Denmark)

    Haastrup, Maija Bruun; Pottegård, Anton; Damkier, Per

    2014-01-01

    While the harmful effects of alcohol during pregnancy are well-established, the consequences of alcohol intake during lactation have been far less examined. We reviewed available data on the prevalence of alcohol intake during lactation, the influence of alcohol on breastfeeding......, the pharmacokinetics of alcohol in lactating women and nursing infants and the effects of alcohol intake on nursing infants. A systematic search was performed in PubMed from origin to May 2013, and 41 publications were included in the review. Approximately half of all lactating women in Western countries consume...... alcohol while breastfeeding. Alcohol intake inhibits the milk ejection reflex, causing a temporary decrease in milk yield. The alcohol concentrations in breast milk closely resemble those in maternal blood. The amount of alcohol presented to nursing infants through breast milk is approximately 5...

  1. Biodegradable and biocompatible polymers for tissue engineering application: a review.

    Science.gov (United States)

    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.

  2. Biodegradable Poly(polyol sebacate) Polymers

    Science.gov (United States)

    Bruggeman, Joost P.; de Bruin, Berend-Jan; Bettinger, Christopher J.; Langer, Robert

    2010-01-01

    We have developed a family of synthetic biodegradable polymers that are composed of structural units endogenous to the human metabolism, designated poly(polyol sebacates) (PPS) polymers. Material properties of PPS polymers can be tuned by altering the polyol monomer and reacting stiochiometric ratio of sebacic acid. These thermoset networks exhibited tensile Young’s moduli ranging from 0.37 ± 0.08 to 378 ± 33 MPa with maximum elongations at break from 10.90 ± 1.37 to 205.16 ± 55.76%, and glass-transition temperatures ranged from ~7 to 46 °C. In vitro degradation under physiological conditions was slower than in vivo degradation rates observed for some PPS polymers. PPS polymers demonstrated similar in vitro and in vivo biocompatibility compared to poly(L-lactic-co-glycolic acid) (PLGA). PMID:18824260

  3. Biodegradable thermogelling polymers: working towards clinical applications.

    Science.gov (United States)

    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. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Partial Discharge Degradation of Several Biodegradable Polymers

    Science.gov (United States)

    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.

  5. Gasoline biodegradation in different soil microcosms

    Directory of Open Access Journals (Sweden)

    Cunha Cláudia Duarte da

    2000-01-01

    Full Text Available The objective of this study was to evaluate gasoline biodegradation in batch soil microcosms. Microorganisms able to grow in the presence of gasoline were isolated from soil. Several treatment systems were performed using both isolated strains and Pseudomonas putida obtained from a culture collection. The treatment system using only autochthonous microflora (system 1 presented an average value of degradation of 50%. The association of Pseudomonas putida, Burkholderia cepacia, Pseudomonas alcaligenes and the native soil microflora (system 13 presented significant percentage of removal of n-undecane (88.7, n-dodecane (61.3 and n-tridecane (66.7. According to these results, systems 1 and 13 revealed considerable potential for application in bioremediation treatments.

  6. Lignin Biodegradation with Laccase-Mediator Systems

    International Nuclear Information System (INIS)

    Christopher, Lew Paul; Yao, Bin; Ji, Yun

    2014-01-01

    Lignin has a significant and largely unrealized potential as a source for the sustainable production of fuels and bulk high-value chemicals. It can replace fossil-based oil as a renewable feedstock that would bring about socio-economic and environmental benefits in our transition to a biobased economy. The efficient utilization of lignin however requires its depolymerization to low-molecular weight phenolics and aromatics that can then serve as the building blocks for chemical syntheses of high-value products. The ability of laccase to attack and degrade lignin in conjunction with laccase mediators is currently viewed as one of the potential “breakthrough” applications for lignin valorization. Here, we review the recent progress in lignin biodegradation with laccase-mediator systems, and research needs that need to be addressed in this field.

  7. Biodegradable polymeric nanocarriers for pulmonary drug delivery.

    Science.gov (United States)

    Rytting, Erik; Nguyen, Juliane; Wang, Xiaoying; Kissel, Thomas

    2008-06-01

    Pulmonary drug delivery is attractive for both local and systemic drug delivery as a non-invasive route that provides a large surface area, thin epithelial barrier, high blood flow and the avoidance of first-pass metabolism. Nanoparticles can be designed to have several advantages for controlled and targeted drug delivery, including controlled deposition, sustained release, reduced dosing frequency, as well as an appropriate size for avoiding alveolar macrophage clearance or promoting transepithelial transport. This review focuses on the development and application of biodegradable polymers to nanocarrier-based strategies for the delivery of drugs, peptides, proteins, genes, siRNA and vaccines by the pulmonary route. The selection of natural or synthetic materials is important in designing particles or nanoparticle clusters with the desired characteristics, such as biocompatibility, size, charge, drug release and polymer degradation rate.

  8. Biodegradation of concrete intended for their decontamination

    International Nuclear Information System (INIS)

    Jestin, A.

    2005-05-01

    The decontamination of sub-structural materials represents a stake of high importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those microorganisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

  9. Optimizing BTEX biodegradation under denitrifying conditions

    International Nuclear Information System (INIS)

    Hutchins, S.R.

    1991-01-01

    Leaking underground storage tanks are a major source of ground water contamination by petroleum hydrocarbons. Gasoline and other fuels contain benzene, toluene, ethylbenzene, and xylenes (collectively known as BTEX), which are hazardous compounds, regulated by the U.S. Environmental Protection Agency (EPA). 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, Michigan, were amended with selected concentrations of nutrients and one or more hydrocarbons. Toluene, ethylbenzene, m-xylene, and p-xylene, were degraded to below 5 micrograms/L when present as sole source substrates; stoichiometric calculations indicated that nitrate removal was sufficient to account for 70 to 80% of the compounds being mineralized. o-Xylene was recalcitrant when present as a sole source substrate, but was slowly degraded in the presence of the other hydrocarbons. Benzene was not degraded within one year, regardless of whether it was available as a sole source substrate or in combination with toluene, phenol, or catechol. Pre-exposure to low levels of BTEX and nutrients had variable effects, as did the addition of different concentrations of ammonia and phosphate. Nitrate concentrations as high as 500 mg/L NO3-N were slightly inhibitory. These data indicate that nitrate-mediated biodegradation of BTEX at Traverse City can occur under a variety of environmental conditions with rates relatively independent of nutrient concentrations. However, the data reaffirm that benzene is recalcitrant under strictly anaerobic conditions in these samples

  10. Biodegradation of carbon nanohorns in macrophage cells

    Science.gov (United States)

    Zhang, Minfang; Yang, Mei; Bussy, Cyrill; Iijima, Sumio; Kostarelos, Kostas; Yudasaka, Masako

    2015-02-01

    With the rapid developments in the medical applications of carbon nanomaterials such as carbon nanohorns (CNHs), carbon nanotubes, and graphene based nanomaterials, understanding the long-term fate, health impact, excretion, and degradation of these materials has become crucial. Herein, the in vitro biodegradation of CNHs was determined using a non-cellular enzymatic oxidation method and two types of macrophage cell lines. Approximately 60% of the CNHs was degraded within 24 h in a phosphate buffer solution containing myeloperoxidase. Furthermore, approximately 30% of the CNHs was degraded by both RAW 264.7 and THP-1 macrophage cells within 9 days. Inflammation markers such as pro-inflammatory cytokines interleukin 6 and tumor necrosis factor α were not induced by exposure to CNHs. However, reactive oxygen species were generated by the macrophage cells after uptake of CNHs, suggesting that these species were actively involved in the degradation of the nanomaterials rather than in an inflammatory pathway induction.With the rapid developments in the medical applications of carbon nanomaterials such as carbon nanohorns (CNHs), carbon nanotubes, and graphene based nanomaterials, understanding the long-term fate, health impact, excretion, and degradation of these materials has become crucial. Herein, the in vitro biodegradation of CNHs was determined using a non-cellular enzymatic oxidation method and two types of macrophage cell lines. Approximately 60% of the CNHs was degraded within 24 h in a phosphate buffer solution containing myeloperoxidase. Furthermore, approximately 30% of the CNHs was degraded by both RAW 264.7 and THP-1 macrophage cells within 9 days. Inflammation markers such as pro-inflammatory cytokines interleukin 6 and tumor necrosis factor α were not induced by exposure to CNHs. However, reactive oxygen species were generated by the macrophage cells after uptake of CNHs, suggesting that these species were actively involved in the degradation of the

  11. Antibacterial biodegradable Mg-Ag alloys

    Directory of Open Access Journals (Sweden)

    D Tie

    2013-06-01

    Full Text Available The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4 and aging (T6 heat treatment.The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant β phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH2 and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7, revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231 and Staphylococcus epidermidis (DSMZ 3269, and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

  12. Biodegradative Activities of Selected Environmental Fungi on a Polyester Polyurethane Varnish and Polyether Polyurethane Foams.

    Science.gov (United States)

    Álvarez-Barragán, Joyce; Domínguez-Malfavón, Lilianha; Vargas-Suárez, Martín; González-Hernández, Ricardo; Aguilar-Osorio, Guillermo; Loza-Tavera, Herminia

    2016-09-01

    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. Polyurethane waste disposal has become a serious problem. In this work, fungal strains able to efficiently degrade different types of polyurethanes are reported, and

  13. Biodegradability relationships among propylene glycol substances in the Organization for Economic Cooperation and Development ready- and seawater biodegradability tests.

    Science.gov (United States)

    West, Robert J; Davis, John W; Pottenger, Lynn H; Banton, Marcy I; Graham, Cynthia

    2007-05-01

    Eight propylene glycol substances, ranging from 1,2-propanediol to a poly(propylene glycol) (PPG) having number-average molecular weight (M(n)) of 2,700 (i.e., PPG 2700), were evaluated in the Organization for Economic Cooperation and Development (OECD) ready- and seawater biodegradability tests. Uniformity in test parameters, such as inoculum source/density and test substance concentrations, combined with frequent measurements of O2 consumption and CO2 evolution, revealed unexpected biodegradability trends across this family of substances. Biodegradability in both tests decreased with increased number of oxy-propylene repeating units (n = 1, 2, 3, 4) of the oligomeric propylene glycols (PGs). However, this trend was reversed for the PPG polymers, and increased biodegradability was observed with increases of average n to seven, 17, and 34 (M(n) = 425, 1,000, and 2,000, respectively). This relationship between molecular weight and biodegradability was reversed again when average n was incremented from 34 (PPG 2000) to 46 (PPG 2700). Six of the tested substances (n = 1, 2, 3, 7, 17, and 34) met the OECD-specified criteria for "ready biodegradability," whereas the tetrapropylene glycol (n = 4) and PPG 2700 substances failed to meet these criteria. Biodegradation half-lives for these eight substances ranged from 3.8 d (PPG 2000) to 33.2 d (PPG 2700) in the ready test, and from 13.6 (PG) to 410 d (PPG 2700) in seawater. Biodegradation half-lives in seawater were significantly correlated with half-lives determined in the ready test. However, half-lives in both tests were correlated poorly with molecular weight, water solubility, and log K(ow). It is speculated that the molecular conformation of these substances, perhaps more so than these other physicochemical properties, has an important role in influencing biodegradability of the propylene glycol substances.

  14. Biodegradation of hydrocarbons exploiting spent substrate from ...

    African Journals Online (AJOL)

    In Acatzingo, Puebla, Mexico (east-central), oil spills have mainly affected agricultural fields. Pleurotus ostreatus is a white rot basidiomycete and produces extracellular enzymes (lacasses, manganese peroxidases, versatile peroxidases and veratryl alcohol oxidases). The production of edible mushrooms generates spent ...

  15. Development of biodegradable polymer based tamoxifen citrate loaded nanoparticles and effect of some manufacturing process parameters on them: a physicochemical and in-vitro evaluation

    Directory of Open Access Journals (Sweden)

    Basudev Sahana

    2010-08-01

    Full Text Available Basudev Sahana, Kousik Santra, Sumit Basu, Biswajit MukherjeeDepartment of Pharmaceutical Technology, Jadavpur University, Kolkata, IndiaAbstract: The aim of the present study was to develop nanoparticles of tamoxifen citrate, a non-steroidal antiestrogenic drug used for the treatment of breast cancer. Biodegradable poly (D, L- lactide-co-glycolide-85:15 (PLGA was used to develop nanoparticles of tamoxifen citrate by multiple emulsification (w/o/w and solvent evaporation technique. Drug-polymer ratio, polyvinyl alcohol concentrations, and homogenizing speeds were varied at different stages of preparation to optimize the desired size and release profile of drug. The characterization of particle morphology and shape was performed by field emission scanning electron microscope (FE-SEM and particle size distribution patterns were studied by direct light scattering method using zeta sizer. In vitro drug release study showed that release profile of tamoxifen from biodegradable nanoparticles varied due to the change in speed of centrifugation for separation. Drug loading efficiency varied from 18.60% to 71.98%. The FE-SEM study showed that biodegradable nanoparticles were smooth and spherical in shape. The stability studies of tamoxifen citrate in the experimental nanoparticles showed the structural integrity of tamoxifen citrate in PLGA nanoparticles up to 60°C in the tested temperatures. Nanoparticles containing tamoxifen citrate could be useful for the controlled delivery of the drug for a prolonged period.Keywords: biodegradable, nanoparticles, PLGA, stability, tamoxifen citrate

  16. Compounds interaction on biodegradation of toluene and methyl ...

    African Journals Online (AJOL)

    MEK) mixtures in a composite bead biofilter was investigated. The biodegradation rate of two compounds in the exponential growth phase and stationary phase for the single compound and two compounds mixing systems was determined.

  17. Anaerobic biodegradation of lipids of the marine microalga Nannochloropsis salina

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Grossi, V.; Blokker, P.

    2001-01-01

    In order to determine the susceptibility to anaerobic biodegradation of the different lipid biomarkers present in a marine microalga containing algaenan, portions of one large batch of cultured Nannochloropsis salina (Eustigmatophyceae) were incubated in anoxic sediment slurries for various times.

  18. Biodegradation of waste PET based copolyesters in thermophilic anaerobic sludge

    Czech Academy of Sciences Publication Activity Database

    Hermanová, S.; Šmejkalová, P.; Merna, J.; Zarevúcka, Marie

    2015-01-01

    Roč. 111, Jan (2015), s. 176-184 ISSN 0141-3910 Institutional support: RVO:61388963 Keywords : poly(ethylene terephthalate) * copolymers * sludge * biodegradation * hydrolysis * waste Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.120, year: 2015

  19. Toward biodegradable nanogel star polymers via organocatalytic ROP.

    Science.gov (United States)

    Appel, Eric A; Lee, Victor Y; Nguyen, Timothy T; McNeil, Melanie; Nederberg, Frederik; Hedrick, James L; Swope, William C; Rice, Jullia E; Miller, Robert D; Sly, Joseph

    2012-06-21

    Organocatalytic ring opening polymerization (OROP) is used to effect the rapid, scalable, room temperature formation of size-controlled, highly uniform, polyvalent, nanogel star polymer nanoparticles of biodegradable composition.

  20. Organic pollutant loading and biodegradability of firefighting foam

    Science.gov (United States)

    Zhang, Xian-Zhong; Bao, Zhi-ming; Hu, Cheng; Li-Shuai, Jing; Chen, Yang

    2017-11-01

    Firefighting foam has been widely used as the high-performance extinguishing agent in extinguishing the liquid poor fire. It was concerned for its environmental impacts due to its massive usage. In this study, the organic loading level and the biodegradability of 18 firefighting foams commonly used in China were evaluated and compared. The COD and TOC of firefighting foam concentrates are extremely high. Furthermore, those of foam solutions are also much higher than regular wastewater. The COD/TOC ratio of synthetic foams are higher than protein foams. The 28-day biodegradation rates of 18 firefighting foams are all over 60%, indicating that they are all ready biodegradable. Protein foams (P, FP and FFFP) have the higher organic loading and lower 28-day biodegradation rates compared to the synthetic foams (Class A foam, AFFF and S). The short and long-term impact of protein foams on the environment are larger than synthetic foams.

  1. COLUMN STUDIES ON BTEX BIODEGRADATION UNDER MICROAEROPHILIC AND DENITRIFYING CONDITIONS

    Science.gov (United States)

    Two column tests were conducted using aquifer material to simulate the nitrate field demonstration project carried out earlier at Traverse City, Michigan. The objectives were to better define the effect nitrate addition had on biodegradation of benzene, toluene, ethylbenzene, xyl...

  2. Biodegradation of Endosulfan by Mixed Bacteria Culture Strains

    African Journals Online (AJOL)

    Nwokem et al.

    Aeruginosa and Staphylococcus Aureus. BIODEGRADATION OF ENDOSULFAN BY MIXED BACTERIA. CULTURE STRAINS OF PSEUDOMONAS AERUGINOSA AND. STAPHYLOCOCCUS AUREUS. Nwokem Nsidibeabasi Calvin1*, Nwokem Calvin Onyedika.2 , Gimba Casmir Emmanuel1 and Iwuala Beatrice Nkiruka1.

  3. Biodegradation of hydrocarbon compounds in Agbabu natural bitumen

    African Journals Online (AJOL)

    Infrared spectral changes and gravimetric analysis from the preliminary biodegradability study carried out on Agbabu Natural Bitumen showed the vulnerability of the bitumen to some bacteria: Pseudomonas putrefaciens, Pseudomonas nigrificans, Bacillus licheniformis, Pseudomonas fragi and Achromobacter aerogenes.

  4. Biodegradation of cycloalkane carboxylic acids in oil sand tailings

    Energy Technology Data Exchange (ETDEWEB)

    Herman, D.C.; Costerton, J.W. (Calgary Univ., Dept. of Biological Sciences, AB (Canada)); Fedorak, P.M. (Alberta Univ., Dept. of Microbiology, AB (Canada))

    1993-01-01

    The biodegradation of both an n-alkane and several carboxylated cycloalkanes was examined experimentally within tailings produced by the extraction of bitumen from the Athabasca oil sands. The carboxylated cycloalkanes examined were structurally similar to naphthenic acids that have been associated with the acute toxicity of oil sand tailings. The biodegradation potential of naphthenic acids was estimated by determining the biodegradation of both the carboxylated cycloalkanes and hexadecane in oil sand tailings. Carboxylated cycloalkanes were biodegraded within oil sands tailings, although compounds with methyl substitutions on the cycloalkane ring were more resistant to microbial degradation. Microbial activity against hexadecane and certain carboxylated cycloalkanes was found to be nitrogen and phosphorus limited. 21 refs., 3 refs., 1 tab.

  5. Biodegradation of phenol by a newly isolated marine bacterial strain ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-26

    peptone agar plates with. 1500 mg/L phenol. ... biodegradation of the strain was up to 92.0% under the optimum conditions even when the phenol ... Growth of marine bacterial isolates in various concentration of phenol. Isolate.

  6. Biodegradation of glyphosate herbicide in vitro using bacterial ...

    African Journals Online (AJOL)

    USER

    2010-06-28

    P. fluorescens and. Acetobacter sp) were ... biotechnology industry and biodegradation of polluted soils and water. Microorganisms known for their ability to degrade glyphosate in soil and water include. Pseudomonas sp ...

  7. Biodegradability and mechanical properties of starch films from Andean crops.

    Science.gov (United States)

    Torres, F G; Troncoso, O P; Torres, C; Díaz, D A; Amaya, E

    2011-05-01

    Different Andean crops were used to obtain starches not previously reported in literature as raw material for the production of biodegradable polymers. The twelve starches obtained were used to prepare biodegradable films by casting. Water and glycerol were used as plasticizers. The mechanical properties of the starch based films were assessed by means of tensile tests. Compost tests and FTIR tests were carried out to assess biodegradability of films. The results show that the mechanical properties (UTS, Young's modulus and elongation at break) of starch based films strongly depend on the starch source used for their production. We found that all the starch films prepared biodegrade following a three stage process and that the weight loss rate of all the starch based films tested was higher than the weight loss rate of the cellulose film used as control. Copyright © 2011 Elsevier B.V. All rights reserved.

  8. Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles

    International Nuclear Information System (INIS)

    Courant, T; Roullin, V G; Andry, M C; Cadiou, C; Chuburu, F; Delavoie, F; Molinari, M; Gafa, V

    2010-01-01

    A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

  9. High-Risk Biodegradable Waste Processing by Alkaline Hydrolysis

    OpenAIRE

    Kalambura, Sanja; Voća, Neven; Krička, Tajana; Šindrak, Zoran; Špehar, Ana; Kalambura, Dejan

    2011-01-01

    Biodegradable waste is by defi nition degraded by other living organisms. Every day, meat industry produces large amounts of a specifi c type of biodegradable waste called slaughterhouse waste. Traditionally in Europe, this waste is recycled in rendering plants which produce meat and bone meal and fat. However, feeding animals with meat and bone meal has been banned since the outbreaks of bovine spongiform encephalopathy (BSE). In consequence, new slaughterhouse waste processing technologies ...

  10. Agronomic evaluation of green biodegradable mulch on melon

    Directory of Open Access Journals (Sweden)

    Ferruccio Filippi

    2011-05-01

    Full Text Available A two-year research was carried out in 2004-2005 in order to evaluate the effects of biodegradable green mulch on melon (Cucumis melo L. var. reticulatus Naud. yield and quality. The loss of quality due to the presence of spot caused by the residues of biodegradable plastics was also investigated. The research was conducted over two years, in open field, at S. Piero a Grado, Pisa, Italy, (lat. 43.67498, long. 10.34737, from the beginning of May to the end of July of each year. The films tested in the first year experiment were two biodegradable ones with different colours (black and green compared with a low-density polyethylene (LDPE film, while in 2005 three biodegradable films, (two green and one black were compared with a traditional LDPE film. The two green biodegradable films had different properties related to the biodegradation rate, faster in film Cv205, because of a different degree of Mater Bi polymer inside the film. In each year a randomized block design with four replications was followed. Green biodegradable films allowed obtaining a higher yield than LDPE films maybe because of the higher soil temperatures reached, and excellent fruit quality, especially for the soluble solids content and the ripening process. At the same time, the presence of residues on the fruit skin was rather low because of the degradation of films occurred at the ripening time. In the first year, the percentage of spotted fruits was low for every kind of film, while in the second one the green film showed a higher presence of residues on skin compared with the black one. The biodegradable materials covered the soil for the whole crop cycle with a good mulching effect, and the successive degradation allowed to avoid the removal and disposal of plastic film, with a certain economic advantage.

  11. Computational analysis for biodegradation of exogenously depolymerizable polymer

    Science.gov (United States)

    Watanabe, M.; Kawai, F.

    2018-03-01

    This study shows that microbial growth and decay in a biodegradation process of exogenously depolymerizable polymer are controlled by consumption of monomer units. Experimental outcomes for residual polymer were incorporated in inverse analysis for a degradation rate. The Gauss-Newton method was applied to an inverse problem for two parameter values associated with the microbial population. A biodegradation process of polyethylene glycol was analyzed numerically, and numerical outcomes were obtained.

  12. A Biodegradable Implant for Restoring Bone Discontinuity Defects in Dogs,

    Science.gov (United States)

    1985-11-01

    determined by observing closure of epiphyses of the distal femur and proximal tibia on roentgenographic films. Animals were verified as being healthy by...Biodegradable Polylac- tic Acid Suture. Oral Surg 31:134, 1971. 4. Cutright DE, Hunsuck EE, Besley JD: Fracture Reduction Using a Biode- gradable Material...Polylactic Acid. J Oral Surg 29:393, 1971. 5. Cutright DE, Hunsuck EE: The Repair of Fractures of the Orbital Floor Using a Biodegradable Material, PLA

  13. Biocompatibility of new drug-eluting biodegradable urethral stent materials.

    Science.gov (United States)

    Kotsar, Andres; Nieminen, Riina; Isotalo, Taina; Mikkonen, Joonas; Uurto, Ilkka; Kellomäki, Minna; Talja, Martti; Moilanen, Eeva; Tammela, Teuvo L J

    2010-01-01

    To investigate the effects of biodegradable stent material (poly-96L/4D-lactic acid [PLA]) on the production of cytokines and other inflammatory mediators in vitro and the biocompatibility of new drug-eluting biodegradable urethral stent materials in vivo. Indomethacin, dexamethasone, and simvastatin were used in the materials. The effects of the biodegradable stent material on cytokines and other inflammatory mediators were measured using the Human Cytokine Antibody Array and enzyme-linked immunosorbent assay in THP-1 cells, with bacterial lipopolysaccharide as a positive control. To assess the biocompatibility of the stent materials, we used muscle implantation. Biodegradable stent materials without drug-eluting properties and silicone and latex were used as controls. The measurements were done at 3 weeks and 3 months. The PLA stent material induced production of inflammatory mediators, especially interleukin-8, tumor necrosis factor-alpha, and transforming growth factor-beta, in vitro. The increase in the production of these mediators with the PLA stent material was smaller than in the cells treated with lipopolysaccharide. In vivo, the effects of the biodegradable materials did not differ at 3 weeks, although, at 3 months, dexamethasone had induced more tissue reactions than had the other materials. At 3 months, fibrosis and chronic inflammatory changes were decreased in the biodegradable material groups compared with the positive control. PLA stent material increased the production of cytokines and other inflammatory mediators less than did positive controls in vitro. The in vivo biocompatibility of the drug-eluting biodegradable materials was better than that of the positive controls. Drug-eluting biodegradable urethral stents could potentially offer a new treatment modality in the future. 2010 Elsevier Inc. All rights reserved.

  14. Global alcohol policy and the alcohol industry.

    Science.gov (United States)

    Anderson, Peter

    2009-05-01

    The WHO is preparing its global strategy on alcohol, and, in so doing, has been asked to consult with the alcohol industry on ways it could contribute in reducing the harm done by alcohol. This review asks which is more effective in reducing harm: the regulatory approaches that the industry does not favour; or the educational approaches that it does favour. The current literature overwhelmingly finds that regulatory approaches (including those that manage the price, availability, and marketing of alcohol) reduce the risk of and the experience of alcohol-related harm, whereas educational approaches (including school-based education and public education campaigns) do not, with industry-funded education actually increasing the risk of harm. The alcohol industry should not be involved in making alcohol policy. Its involvement in implementing policy should be restricted to its role as a producer, distributor, and marketer of alcohol. In particular, the alcohol industry should not be involved in educational programmes, as such involvement could actually lead to an increase in harm.

  15. Calcium orthophosphate coatings on magnesium and its biodegradable alloys.

    Science.gov (United States)

    Dorozhkin, Sergey V

    2014-07-01

    Biodegradable metals have been suggested as revolutionary biomaterials for bone-grafting therapies. Of these metals, magnesium (Mg) and its biodegradable alloys appear to be particularly attractive candidates due to their non-toxicity and as their mechanical properties match those of bones better than other metals do. Being light, biocompatible and biodegradable, Mg-based metallic implants have several advantages over other implantable metals currently in use, such as eliminating both the effects of stress shielding and the requirement of a second surgery for implant removal. Unfortunately, the fast degradation rates of Mg and its biodegradable alloys in the aggressive physiological environment impose limitations on their clinical applications. This necessitates development of implants with controlled degradation rates to match the kinetics of bone healing. Application of protective but biocompatible and biodegradable coatings able to delay the onset of Mg corrosion appears to be a reasonable solution. Since calcium orthophosphates are well tolerated by living organisms, they appear to be the excellent candidates for such coatings. Nevertheless, both the high chemical reactivity and the low melting point of Mg require specific parameters for successful deposition of calcium orthophosphate coatings. This review provides an overview of current coating techniques used for deposition of calcium orthophosphates on Mg and its biodegradable alloys. The literature analysis revealed that in all cases the calcium orthophosphate protective coatings both increased the corrosion resistance of Mg-based metallic biomaterials and improved their surface biocompatibility. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  16. [Biodegradation characteristics of organic pollutants contained in tannery wastewater].

    Science.gov (United States)

    Wang, Yong; Li, Wei-Guang; Yang, Li; Su, Cheng-Yuan

    2013-02-01

    In the batch experiments inoculated with activated sludge from tannery wastewater treatment plant, biodegradation characteristics and kinetics of three tanning agents, naphthalene-2-sulfonic sodium, tannic acid and bayberry tannin, were studied under aerobic and anaerobic conditions. And the aerobic/anaerobic biodegradation laws of real tannery wastewater with respect to COD change were also investigated using the same batch experiments. The results showed aerobic degradation was superior to anaerobic degradation for tanning agent removal and mineralization. The removal rates of naphthalene-2-sulfonic sodium, tannic acid and bayberry tannin by aerobic biodegradation were >90% , >90% and 50% -75% , respectively whereas 10%-40%, >95% and 20% -30%, respectively by anaerobic degradation. In terms of COD removal about tannic acid biodegradation, the removal rates under aerobic and anaerobic conditions were >75% and tannin were slightly influenced by initial concentrations while initial concentration had a significant effect on the first-order kinetics rate in the case of naphthalene-2-sulfonic sodium aerobic-biodegradation because naphthalene- 2-sulfonic sodium with initial concentration >or= 70 mg.L-1 was toxic to microorganism leading to a significant decline of kinetic constants. Biodegradation of real tannery wastewater under aerobic and anaerobic conditions represented obvious stage characteristics and the COD concentration had a good linear correlation with reaction time in the phases of fast degradation and slow degradation. The aerobic maximum specific degradation rate wqas 11.6 times higher of anaerobic degradation.

  17. Biodegradable polymers for targeted delivery of anti-cancer drugs.

    Science.gov (United States)

    Doppalapudi, Sindhu; Jain, Anjali; Domb, Abraham J; Khan, Wahid

    2016-06-01

    Biodegradable polymers have been used for more than three decades in cancer treatment and have received increased interest in recent years. A range of biodegradable polymeric drug delivery systems designed for localized and systemic administration of therapeutic agents as well as tumor-targeting macromolecules has entered into the clinical phase of development, indicating the significance of biodegradable polymers in cancer therapy. This review elaborates upon applications of biodegradable polymers in the delivery and targeting of anti-cancer agents. Design of various drug delivery systems based on biodegradable polymers has been described. Moreover, the indication of polymers in the targeted delivery of chemotherapeutic drugs via passive, active targeting, and localized drug delivery are also covered. Biodegradable polymer-based drug delivery systems have the potential to deliver the payload to the target and can enhance drug availability at desired sites. Systemic toxicity and serious side effects observed with conventional cancer therapeutics can be significantly reduced with targeted polymeric systems. Still, there are many challenges that need to be met with respect to the degradation kinetics of the system, diffusion of drug payload within solid tumors, targeting tumoral tissue and tumor heterogeneity.

  18. Saponification of fatty slaughterhouse wastes for enhancing anaerobic biodegradability.

    Science.gov (United States)

    Battimelli, Audrey; Carrère, Hélène; Delgenès, Jean-Philippe

    2009-08-01

    The thermochemical pretreatment by saponification of two kinds of fatty slaughterhouse waste--aeroflotation fats and flesh fats from animal carcasses--was studied in order to improve the waste's anaerobic degradation. The effect of an easily biodegradable compound, ethanol, on raw waste biodegradation was also examined. The aims of the study were to enhance the methanisation of fatty waste and also to show a link between biodegradability and bio-availability. The anaerobic digestion of raw waste, saponified waste and waste with a co-substrate was carried out in batch mode under mesophilic and thermophilic conditions. The results showed little increase in the total volume of biogas, indicating a good biodegradability of the raw wastes. Mean biogas volume reached 1200 mL/g VS which represented more than 90% of the maximal theoretical biogas potential. Raw fatty wastes were slowly biodegraded whereas pretreated wastes showed improved initial reaction kinetics, indicating a better initial bio-availability, particularly for mesophilic runs. The effects observed for raw wastes with ethanol as co-substrate depended on the process temperature: in mesophilic conditions, an initial improvement was observed whereas in thermophilic conditions a significant decrease in biodegradability was observed.

  19. Consumo de alcohol alcoholismo

    OpenAIRE

    Rodríguez Páez, Pablo E.; Fundación Valle de Lili

    1999-01-01

    ¿Qué es el alcohol?/¿Cómo actual el alcohol en el organismo?/¿Qué efectos causa?/Efectos por el consumo crónico/¿El consumo de alcohol durante el embarazo afecta el embrión?/¿Qué otras consecuencias tiene el consumo de alcohol?/¿Cuándo se considera que una persona tiene problemas con su consumo de alcohol?/¿Cuándo se debe sospechar que alguien tiene problemas con el consumo de alcohol?/Características del saber beber adecuadamente?/¿Cuales son las alternativas de tratamiento para este problem...

  20. State-of-the-art of biodegradable composite materials; Etat de l'art sur les materiaux composites biodegradables

    Energy Technology Data Exchange (ETDEWEB)

    Baley, Ch.; Grohens, Y.; Pillin, I. [Universite de Bretagne Sud, Lab. Polymeres, Proprietes aux Interfaces et Composites, 56 - Lorient (France)

    2004-07-01

    Nowadays, the market demand for environment friendly materials is in strong growth. The biodegradable composites (biodegradable fibres and polymers) mainly extracted from renewable resources will be a major contributor to the production of new industrial high performance products partially solving the problem of waste management. At the end of the lifetime, a structural bio-composite could be be crushed and recycled through a controlled industrial composting process. This the state-of-the-art report focuses on the biopolymers the vegetable fibres properties, the mechanisms of biodegradation and the examples of biodegradable composites. Eco-design of new products requires these new materials for which a life cycle analysis is nevertheless necessary to validate their environmental benefits. (authors)

  1. Alcoholic hepatitis.

    Science.gov (United States)

    Damgaard Sandahl, Thomas

    2014-10-01

    Alcoholic hepatitis (AH) is an acute inflammatory syndrome causing significant morbidity and mortality. The prognosis is strongly dependent on disease severity, as assessed by clinical scoring systems. Reliable epidemiological data as well as knowledge of the clinical course of AH are essential for planning and resource allocation within the health care system. Likewise, individual evaluation of risk is desirable in the clinical handling of patients with AH as it can guide treatment, improve patient information, and serve as strata in clinical trials. The present PhD thesis is based on three studies using a cohort of nearly 2000 patients diagnosed with AH in Denmark from 1999 to 2008 as a cohort, in a population-based study design. The aims of this thesis were as follows. (1) To describe the incidence and short- and long-term mortality, of AH in Denmark (Study I). (2) To validate and compare the ability of the currently available prognostic scores to predict mortality in AH (Study II). (3) To investigate the short- and long-term causes of death of patients with AH (Study III). During the study decade, the annual incidence rate in the Danish population rose from 37 to 46 per 106 for men and from 24 to 34 per 106 for women. Both short- and long-term mortality rose for men and women, and the increase in short-term mortality was attributable to increasing patient age and prevalence of cirrhosis. Our evaluation of the most commonly used prognostic scores for predicting the mortality of patients with AH showed that all scores performed similarly, with Area under the Receiver Operator Characteristics curves giving values between 0.74 and 0.78 for 28-day mortality assessed on admission. Our study on causes of death showed that in the short-term (thesis provides novel warranted epidemiological information about AH that shows increasing incidence and mortality rates. Consequently, it reiterates the fact that AH is a life-threatening disease and suggests that AH is an

  2. Environmental properties of long chain alcohols. Part 1: Physicochemical, environmental fate and acute aquatic toxicity properties

    DEFF Research Database (Denmark)

    Fisk, Peter; Sanderson, Hans; Wildey, Ross

    2009-01-01

    )SARs). This allows predictions of data relating to human and environmental safety profiles and patterns. These alcohols have been shown to be rapidly degradable under standard conditions up to C18. Furthermore, evidence suggests that longer chain lengths are also rapidly biodegradable. While log Kow values suggest......This paper summarises the physicochemical, biodegradation and acute aquatic ecotoxicity properties of long chain aliphatic alcohols. Properties of pure compounds are shown to follow somewhat predictable trends, which are amenable to estimation by quantitative structure-activity relationships ((Q...... possible bioaccumulation potential, available data suggest that these substances are not as bioaccumulative as estimations would predict. For acute aquatic toxicity, solubility limits the possibility of effects being appropriately observed and become increasingly challenging above C12. Further, a model has...

  3. Fetal alcohol effects in alcoholic veteran patients.

    Science.gov (United States)

    Tishler, P V; Henschel, C E; Ngo, T A; Walters, E E; Worobec, T G

    1998-11-01

    Fetal alcohol syndrome is often associated with severe physical and neuropsychiatric maldevelopment. On the other hand, some offspring of women who drank during pregnancy appear to be affected in minimal ways and function relatively well within society. We questioned whether this effect of prenatal alcohol in the adult is generally minimal. To bear on this, we determined whether we could distinguish alcohol-exposed from nonexposed individuals in a population of male veterans, selected because of both their accepted level of function within society (e.g., honorable discharge from the military) and their admission to an alcohol treatment unit (thus, a greater likelihood of parental alcoholism, because of its familial aggregation). Consecutively admitted alcoholics (cases; n = 77) with likely maternal alcohol ingestion during their pregnancy or the first 10 years of life were matched with alcoholics with no maternal alcohol exposure during these periods (controls; n = 161). Each subject completed questionnaires regarding personal birthweight, alcohol, drug, educational and work histories, and family (including parental) alcohol and drug histories. We measured height, weight, and head circumference; checked for facial and hand anomalies; and took a frontal facial photograph, from which measurements of features were made. Data were analyzed by univariate statistics and stepwise logistic regression. No case had bona fide fetal alcohol syndrome. With univariate statistical analyses, the cases differed from the controls in 10 variables, including duration of drinking, width of alae nasae, being hyperactive or having a short attention span, and being small at birth. By stepwise logistic regression, the variables marital status, small size at birth, duration of drinking, and the presence of a smooth philtrum were marginally (the first two) or definitely (the last two) significant predictors of case status. Analysis of only the 37 cases in whom maternal prenatal drinking was

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

    Science.gov (United States)

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

    2017-08-01

    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. Three hundred and forty-one people (34% women) in the Paris area were questioned on their trajectories with a biographical questionnaire. Some open questions were aimed to understand the connection they made between events in their lives, how recovered they felt and what they considered strengths or obstacles. All the participants had stopped at least one product. Their mean age was 43, and 26% were over 50. How can the differences between one substance addicts and dual abusers be explained? Can we hypothesize a better result for the patients with a single dependence to alcohol in their lives for the following two reasons? (1) They could really be taken in charge for their alcoholism whereas the dual abusers mostly receive cared for their illicit drug problems with an under estimation of their problem with alcohol. In this case, they turn to alcohol after weaning themselves from their drug dependence so as to return to a social consumption, especially when they are given an opiate treatment. (2) Conversely could we suggest that the dual substance abusers had different trajectories from their childhood (more adverse events, more social difficulties, mental health problems), and that this accumulation explains their skipping from one substance or behaviour to another without any real recovery for decades? All respondents were polydrug users. Eighty-two had been dependent mainly on alcohol. One hundred and twenty-one people had been drug addicts (mostly heroin), which they had stopped on average ten years before the survey. The last group included 138 persons who had been heroin or cocaine addicts and alcoholics in their lives, a third of whom had been dependent on alcohol before their drug addiction (35%), a tenth on both at the same time (10

  5. Fetal Alcohol Spectrum Disorders.

    Science.gov (United States)

    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. Copyright © 2015 by the American Academy of Pediatrics.

  6. Biodegradable starch-based polymeric materials

    Science.gov (United States)

    Suvorova, Anna I.; Tyukova, Irina S.; Trufanova, Elena I.

    2000-05-01

    The effects of low-molecular-weight additives, temperature and mechanical action on the structure and properties of starch are discussed. Special attention is given to mixtures of starch with synthetic polymers, e.g., co-polymers of ethylene with vinyl acetate, vinyl alcohol, acrylic acid, cellulose derivatives and other natural polymers. These mixtures can be used in the development of novel environmentally safe materials (films, coatings, packaging materials) and various articles for short-term use. The bibliography includes 105 references.

  7. Evaluation of the biodegradation of Alaska North Slope oil in microcosms using the biodegradation model BIOB

    Directory of Open Access Journals (Sweden)

    Jagadish eTorlapati

    2014-05-01

    Full Text Available 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 the decay rate of the overall PAH.

  8. Kids and Alcohol (For Parents)

    Science.gov (United States)

    ... Videos for Educators Search English Español Kids and Alcohol KidsHealth / For Parents / Kids and Alcohol What's in ... it as they grow up. The Effects of Alcohol Abuse Alcohol interferes with a person's perception of ...

  9. Genetics of Alcoholism.

    Science.gov (United States)

    Zhu, Ena C; Soundy, Timothy J; Hu, Yueshan

    2017-05-01

    Consuming excessive amounts of alcohol has the potential to modify an individual's brain and lead to alcohol dependence. Alcohol use leads to 88,000 deaths every year in the U.S. alone and can lead to other health issues including cancers, such as colorectal cancer, and mental health problems. While drinking behavior varies due to environmental factors, genetic factors also contribute to the risk of alcoholism. Certain genes affecting alcohol metabolism and neurotransmitters have been found to contribute to or inhibit the risk. Geneenvironment interactions may also play a role in the susceptibility of alcoholism. With a better understanding of the different components that can contribute to alcoholism, more personalized treatment could cater to the individual. This review discusses the major genetic factors and some small variants in other genes that contribute to alcoholism, as well as considers the gene-environmental interactions. Copyright© South Dakota State Medical Association.

  10. Naltrexone for Alcoholism

    Science.gov (United States)

    ... areas are blocked, you feel less need to drink alcohol. You don’t feel the “high” sensation that ... does not make you feel sick if you drink alcohol while taking it. How long will I take ...

  11. Children of alcoholics

    Directory of Open Access Journals (Sweden)

    Robert Oravecz

    2002-09-01

    Full Text Available The author briefly interprets the research – results, referring to the phenomenon of children of alcoholics, especially the psychological and psychopathological characteristics of children of alcoholics in adolescence and young adulthood. The author presents a screening study of adolescents. The sample contains 200 high school students at age 18. The aim of the survey was to discover the relationship between alcohol consumption of parents, PTSD - related psychopathological symptoms and reported life quality of their children. The study confirmed the hypothesis about a substantial correlation between high alcohol consumption of parents, higher psychopathological symptom - expression and lower reported life quality score of their children. Higher PTSD-related symptomatology in children of alcoholics is probably resulted by home violence, which is very often present in family of alcoholics. The article also evaluated the results regarding suicide ideation of children of alcoholics, which is definitely more frequent and more intense than in their peers living in non alcohol – dependent families.

  12. Antidepressants and Alcohol

    Science.gov (United States)

    ... the concern? Why is it bad to mix antidepressants and alcohol? Answers from Daniel K. Hall-Flavin, M.D. It's best to avoid combining antidepressants and alcohol. It may worsen your symptoms, and ...

  13. Benzyl Alcohol Topical

    Science.gov (United States)

    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. ...

  14. Fetal Alcohol Spectrum Disorders

    Science.gov (United States)

    Alcohol can harm your baby at any stage during a pregnancy. That includes the earliest stages, before ... can cause a group of conditions called fetal alcohol spectrum disorders (FASDs). Children who are born with ...

  15. Myths about drinking alcohol

    Science.gov (United States)

    ... 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. Alcohol and Cancer Risk

    Science.gov (United States)

    ... Cancer Genetics Services Directory Cancer Prevention Overview Research Alcohol and Cancer Risk On This Page What is ... in the risk of colorectal cancer. Research on alcohol consumption and other cancers: Numerous studies have examined ...

  17. Women and Alcohol

    Science.gov (United States)

    ... 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 ...

  18. Biodegradation and flushing of MBT wastes

    Energy Technology Data Exchange (ETDEWEB)

    Siddiqui, A.A., E-mail: aasiddiqui.cv@amu.ac.in [Department of Civil Engineering, Aligarh Muslim University, Aligarh 202002 (India); Richards, D.J.; Powrie, W. [Waste Management Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2013-11-15

    Highlights: • Stabilization was achieved for MBT wastes of different degrees of pretreatment. • About 92% reduction in the gas generation compared with raw MSW. • Pretreatment resulted in reduced TOC, nitrogen and heavy metals in leachate. • A large proportion of carbon and nitrogen remained in the waste material. - Abstract: 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 ∼320 g/kg dry matter for raw MSW to between 183 and 195 g/kg dry matter for the MBT wastes.

  19. Biodegradation and flushing of MBT wastes

    International Nuclear Information System (INIS)

    Siddiqui, A.A.; Richards, D.J.; Powrie, W.

    2013-01-01

    Highlights: • Stabilization was achieved for MBT wastes of different degrees of pretreatment. • About 92% reduction in the gas generation compared with raw MSW. • Pretreatment resulted in reduced TOC, nitrogen and heavy metals in leachate. • A large proportion of carbon and nitrogen remained in the waste material. - Abstract: 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 ∼320 g/kg dry matter for raw MSW to between 183 and 195 g/kg dry matter for the MBT wastes

  20. Biogeochemistry of anaerobic crude oil biodegradation

    Science.gov (United States)

    Head, Ian; Gray, Neil; Aitken, Caroline; Sherry, Angela; Jones, Martin; Larter, Stephen

    2010-05-01

    Anaerobic degradation of crude oil and petroleum hydrocarbons is widely recognized as a globally significant process both in the formation of the world's vast heavy oil deposits and for the dissipation of hydrocarbon pollution in anoxic contaminated environments. Comparative analysis of crude oil biodegradation under methanogenic and sulfate-reducing conditions has revealed differences not only in the patterns of compound class removal but also in the microbial communities responsible. Under methanogenic conditions syntrophic associations dominated by bacteria from the Syntropheaceae are prevalent and these are likely key players in the initial anaerobic degradation of crude oil alkanes to intermediates such as hydrogen and acetate. Syntrophic acetate oxidation plays an important role in these systems and often results in methanogenesis dominated by CO2 reduction by members of the Methanomicrobiales. By contrast the bacterial communities from sulfate-reducing crude oil-degrading systems were more diverse and no single taxon dominated the oil-degrading sulfate-reducing systems. All five proteobacterial subdivisions were represented with Delta- and Gammaproteobacteria being detected most consistently. In sediments which were pasteurized hydrocarbon degradation continued at a relatively low rate. Nevertheless, alkylsuccinates characteristic of anaerobic hydrocarbon degradation accumulated to high concentrations. This suggested that the sediments harbour heat resistant, possibly spore-forming alkane degrading sulfate-reducers. This is particularly interesting since it has been proposed recently, that spore-forming sulfate-reducing bacteria found in cold arctic sediments may have originated from seepage of geofluids from deep subsurface hydrocarbon reservoirs.

  1. Biodegradation and bioremediation of endosulfan contaminated soil.

    Science.gov (United States)

    Kumar, Mohit; Lakshmi, C Vidya; Khanna, Sunil

    2008-05-01

    Among the three mixed bacterial culture AE, BE, and CE, developed by enrichment technique with endosulfan as sole carbon source, consortium CE was found to be the most efficient with 72% and 87% degradation of alpha-endosulfan and beta-endosulfan, respectively, in 20 days. In soil microcosm, consortium AE, BE and CE degraded alpha-endosulfan by 57%, 88% and 91%, respectively, whereas beta-endosulfan was degraded by 4%, 60% and 67% after 30 days. Ochrobacterum sp., Arthrobacter sp., and Burkholderia sp., isolated and identified on the basis of 16s rDNA gene sequence, individually showed in situ biodegradation of alpha-endosulfan in contaminated soil microcosm by 61, 73, and 74, respectively, whereas degradation of beta-endosulfan was 63, 75, and 62, respectively, after 6 weeks of incubation over the control which showed 26% and 23 % degradation of alpha-endosulfan and beta-endosulfan, respectively. Population survival of Ochrobacterum sp., Arthrobacter sp., and Burkholderia sp., by plate count on Luria Broth with carbenicillin showed 75-88% survival of these isolates as compared to 36-48% of survival obtained from PCR fingerprinting. Arthrobacter sp. oxidized endosulfan to endosulfan sulfate which was further metabolized but no known metabolite of endosulfan sulfate was detected.

  2. Biodegradation of chlorpyrifos by bacterial genus Pseudomonas.

    Science.gov (United States)

    Gilani, Razia Alam; Rafique, Mazhar; Rehman, Abdul; Munis, Muhammad Farooq Hussain; Rehman, Shafiq Ur; Chaudhary, Hassan Javed

    2016-02-01

    Chlorpyrifos is an organophosphorus pesticide commonly used in agriculture. It is noxious to a variety of organisms that include living soil biota along with beneficial arthropods, fish, birds, humans, animals, and plants. Exposure to chlorpyrifos may cause detrimental effects as delayed seedling emergence, fruit deformities, and abnormal cell division. Contamination of chlorpyrifos has been found about 24 km from the site of its application. There are many physico-chemical and biological approaches to remove organophosphorus pesticides from the ecosystem, among them most promising is biodegradation. The 3,5,6-trichloro-2-pyridinol (TCP) and diethylthiophosphate (DETP) as primary products are made when chlorpyrifos is degraded by soil microorganisms which further break into nontoxic metabolites as CO(2), H(2)O, and NH(3). Pseudomonas is a diversified genus possessing a series of catabolic pathways and enzymes involved in pesticide degradation. Pseudomonas putida MAS-1 is reported to be more efficient in chlorpyrifos degradation by a rate of 90% in 24 h among Pseudomonas genus. The current review analyzed the comparative potential of bacterial species in Pseudomonas genus for degradation of chlorpyrifos thus, expressing an ecofriendly approach for the treatment of environmental contaminants like pesticides. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Microbial ecology of bacterially mediated PCB biodegradation

    International Nuclear Information System (INIS)

    Pettigrew, C.A. Jr.

    1989-01-01

    The roles of plasmid mediated and consortia mediated polychlorinated biphenyl (PCB) biodegradation by bacterial populations isolated from PCB contaminated freshwater sediments were investigated. PCB degrading bacteria were isolated by DNA:DNA colony hybridization, batch enrichments, and chemostat enrichment. Analysis of substrate removal and metabolite production were done using chlorinated biphenyl spray plates, reverse phase high pressure liquid chromatography, Cl - detection, and 14 C-labeled substrate mineralization methods. A bacterial consortium, designated LPS10, involved in a concerted metabolic attack on chlorinated biphenyls, was shown to mineralize 4-chlorobiphenyl (4CB) and 4,4'-dichlorobiphenyl (4,4' CB). The LPS10 consortium was isolated by both batch and chemostat enrichment using 4CB and biphenyl (BP) as sole carbon source and was found to have tree bacterial isolates that predominated; these included: Pseudomonas, testosteroni LPS10A which mediated the breakdown of 4CB and 4,4' CB to the putative meta-cleavage product and subsequently to 4-chlorobenzoic acid (4CBA), an isolate tentatively identified as an Arthrobacter sp. LPS10B which mediated 4CBA degradation, and Pseudomonas putida by A LPS10C whose role in the consortium has not been determined

  4. Biodegradable mesoporous delivery system for biomineralization precursors.

    Science.gov (United States)

    Yang, Hong-Ye; Niu, Li-Na; Sun, Jin-Long; Huang, Xue-Qing; Pei, Dan-Dan; Huang, Cui; Tay, Franklin R

    2017-01-01

    Scaffold supplements such as nanoparticles, components of the extracellular matrix, or growth factors have been incorporated in conventional scaffold materials to produce smart scaffolds for tissue engineering of damaged hard tissues. Due to increasing concerns on the clinical side effects of using large doses of recombinant bone-morphogenetic protein-2 in bone surgery, it is desirable to develop an alternative nanoscale scaffold supplement that is not only osteoinductive, but is also multifunctional in that it can perform other significant bone regenerative roles apart from stimulation of osteogenic differentiation. Because both amorphous calcium phosphate (ACP) and silica are osteoinductive, a biodegradable, nonfunctionalized, expanded-pore mesoporous silica nanoparticle carrier was developed for loading, storage, and sustained release of a novel, biosilicification-inspired, polyamine-stabilized liquid precursor phase of ACP for collagen biomineralization and for release of orthosilicic acid, both of which are conducive to bone growth. Positively charged poly(allylamine)-stabilized ACP (PAH-ACP) could be effectively loaded and released from nonfunctionalized expanded-pore mesoporous silica nanoparticles (pMSN). The PAH-ACP released from loaded pMSN still retained its ability to infiltrate and mineralize collagen fibrils. Complete degradation of pMSN occurred following unloading of their PAH-ACP cargo. Because PAH-ACP loaded pMSN possesses relatively low cytotoxicity to human bone marrow-derived mesenchymal stem cells, these nanoparticles may be blended with any osteoconductive scaffold with macro- and microporosities as a versatile scaffold supplement to enhance bone regeneration.

  5. Melt electrospinning of biodegradable polyurethane scaffolds.

    Science.gov (United States)

    Karchin, Ari; Simonovsky, Felix I; Ratner, Buddy D; Sanders, Joan E

    2011-09-01

    Electrospinning from a melt, in contrast to from a solution, is an attractive tissue engineering scaffold manufacturing process as it allows for the formation of small diameter fibers while eliminating potentially cytotoxic solvents. Despite this, there is a dearth of literature on scaffold formation via melt electrospinning. This is likely due to the technical challenges related to the need for a well-controlled high-temperature setup and the difficulty in developing an appropriate polymer. In this paper, a biodegradable and thermally stable polyurethane (PU) is described specifically for use in melt electrospinning. Polymer formulations of aliphatic PUs based on (CH(2))(4)-content diisocyanates, polycaprolactone (PCL), 1,4-butanediamine and 1,4-butanediol (BD) were evaluated for utility in the melt electrospinning process. The final polymer formulation, a catalyst-purified PU based on 1,4-butane diisocyanate, PCL and BD in a 4/1/3M ratio with a weight-average molecular weight of about 40kDa, yielded a nontoxic polymer that could be readily electrospun from the melt. Scaffolds electrospun from this polymer contained point bonds between fibers and mechanical properties analogous to many in vivo soft tissues. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  6. Biodegradation, biodistribution and toxicity of chitosan.

    Science.gov (United States)

    Kean, T; Thanou, M

    2010-01-31

    Chitosan is a natural polysaccharide that has attracted significant scientific interest during the last two decades. It is a potentially biologically compatible material that is chemically versatile (-NH2 groups and various M(w)). These two basic properties have been used by drug delivery and tissue engineering scientists to create a plethora of formulations and scaffolds that show promise in healthcare. Despite the high number of published studies, chitosan is not approved by the FDA for any product in drug delivery, and as a consequence very few biotech companies are using this material. This review will aim to provide information on these biological properties that affect chitosan's safe use in drug delivery. The term "Chitosan" represents a large group of structurally different chemical entities that may show different biodistribution, biodegradation and toxicological profiles. Here we aim to review research in this area and critically discuss chitosan's potential to be used as a generally regarded as safe (GRAS) material. 2009 Elsevier B.V. All rights reserved.

  7. Electrospun biodegradable polymers loaded with bactericide agents

    Directory of Open Access Journals (Sweden)

    Ramaz Katsarava

    2016-03-01

    Full Text Available Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furthermore, the technique is versatile since different constructs (e.g. those derived from single electrospinning, co-electrospinning, coaxial electrospinning, and miniemulsion electrospinning can be obtained to influence the ability to load agents with different characteristics and stability and to modify the release behaviour. Furthermore, antimicrobial agents can be loaded during the electrospinning process or by a subsequent coating process. In order to the mitigate burst release effect, it is possible to encapsulate the selected drug into inorganic nanotubes and nanoparticles, as well as in organic cyclodextrine polysaccharides. In the same way, processes that involve covalent linkage of bactericide agents during surface treatment of electrospun samples may also be considered. The present review is focused on more recent works concerning the electrospinning of antimicrobial polymers. These include chitosan and common biodegradable polymers with activity caused by the specific load of agents such as metal and metal oxide particles, quaternary ammonium compounds, hydantoin compounds, antibiotics, common organic bactericides, and bacteriophages.

  8. Alcohol Saliva Strip Test

    OpenAIRE

    Thokala, Madhusudhana Rao; Dorankula, Shyam Prasad Reddy; Muddana, Keertrthi; Velidandla, Surekha Reddy

    2014-01-01

    Alcohol is a factor in many categories of injury. Alcohol intoxication is frequently associated with injuries from falls, fires, drowning, overdoses, physical and sexual abusements, occupational accidents, traffic accidents and domestic violence. In many instances, for forensic purpose, it may be necessary to establish whether the patients have consumed alcohol that would have been the reason for the injury/accidents. Combining rapidity and reliability, alcohol saliva strip test (AST) has bee...

  9. Television: Alcohol's Vast Adland.

    Science.gov (United States)

    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…

  10. Alcohol Facts and Statistics

    Science.gov (United States)

    ... attributable to alcohol consumption. 12 In 2014, the World Health Organization reported that alcohol contributed to more than 200 ... Medicine 49(5):e73– e79, 2015. PMID: 26477807 World Health Organization (WHO). Global Status Report on Alcohol and Health. ...

  11. (HCV) among alcoholics

    African Journals Online (AJOL)

    GREGORY

    2010-12-21

    Dec 21, 2010 ... and seventy (270) alcoholics and fifty (50) control subjects at selected locations in Jos South local ... subjects. Overall, the prevalence of HCV infection was found to be 45(16.7%) in response to alcoholics while the non-alcoholic (control) subjects recorded 3 (6.0%) positivity, [(x2 ... the family Flaviviridae.

  12. Alcohol and Aggression.

    Science.gov (United States)

    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…

  13. Alcoholism and Lesbians

    Science.gov (United States)

    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…

  14. Factors limiting sulfolane biodegradation in contaminated subarctic aquifer substrate.

    Directory of Open Access Journals (Sweden)

    Christopher P Kasanke

    Full Text Available Sulfolane, a water-soluble organosulfur compound, is used industrially worldwide and is associated with one of the largest contaminated groundwater plumes in the state of Alaska. Despite being widely used, little is understood about the degradation of sulfolane in the environment, especially in cold regions. We conducted aerobic and anaerobic microcosm studies to assess the biological and abiotic sulfolane degradation potential of contaminated subarctic aquifer groundwater and sediment from Interior Alaska. We also investigated the impacts of nutrient limitations and hydrocarbon co-contamination on sulfolane degradation. We found that sulfolane underwent biodegradation aerobically but not anaerobically under nitrate, sulfate, or iron-reducing conditions. No abiotic degradation activity was detectable under either oxic or anoxic conditions. Nutrient addition stimulated sulfolane biodegradation in sediment slurries at high sulfolane concentrations (100 mg L-1, but not at low sulfolane concentrations (500 μg L-1, and nutrient amendments were necessary to stimulate sulfolane biodegradation in incubations containing groundwater only. Hydrocarbon co-contamination retarded aerobic sulfolane biodegradation rates by ~30%. Our study is the first to investigate the sulfolane biodegradation potential of subarctic aquifer substrate and identifies several important factors limiting biodegradation rates. We concluded that oxygen is an important factor limiting natural attenuation of this sulfolane plume, and that nutrient amendments are unlikely to accelerate biodegradation within in the plume, although they may biostimulate degradation in ex situ groundwater treatment applications. Future work should be directed at elucidating the identity of indigenous sulfolane-degrading microorganisms and determining their distribution and potential activity in the environment.

  15. Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Francois, A.

    2002-11-01

    Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

  16. Alcohol and breastfeeding.

    Science.gov (United States)

    Haastrup, Maija Bruun; Pottegård, Anton; Damkier, Per

    2014-02-01

    While the harmful effects of alcohol during pregnancy are well-established, the consequences of alcohol intake during lactation have been far less examined. We reviewed available data on the prevalence of alcohol intake during lactation, the influence of alcohol on breastfeeding, the pharmacokinetics of alcohol in lactating women and nursing infants and the effects of alcohol intake on nursing infants. A systematic search was performed in PubMed from origin to May 2013, and 41 publications were included in the review. Approximately half of all lactating women in Western countries consume alcohol while breastfeeding. Alcohol intake inhibits the milk ejection reflex, causing a temporary decrease in milk yield. The alcohol concentrations in breast milk closely resemble those in maternal blood. The amount of alcohol presented to nursing infants through breast milk is approximately 5-6% of the weight-adjusted maternal dose, and even in a theoretical case of binge drinking, the children would not be subjected to clinically relevant amounts of alcohol. Newborns metabolize alcohol at approximately half the rate of adults. Minute behavioural changes in infants exposed to alcohol-containing milk have been reported, but the literature is contradictory. Any long-term consequences for the children of alcohol-abusing mothers are yet unknown, but occasional drinking while breastfeeding has not been convincingly shown to adversely affect nursing infants. In conclusion, special recommendations aimed at lactating women are not warranted. Instead, lactating women should simply follow standard recommendations on alcohol consumption. © 2013 Nordic Pharmacological Society. Published by John Wiley & Sons Ltd.

  17. Anaerobic hydrocarbon biodegradation in deep subsurface oil reservoirs.

    Science.gov (United States)

    Aitken, Carolyn M; Jones, D M; Larter, S R

    2004-09-16

    Biodegradation of crude oil in subsurface petroleum reservoirs is an important alteration process with major economic consequences. Aerobic degradation of petroleum hydrocarbons at the surface is well documented and it has long been thought that the flow of oxygen- and nutrient-bearing meteoric waters into reservoirs was necessary for in-reservoir petroleum biodegradation. The occurrence of biodegraded oils in reservoirs where aerobic conditions are unlikely, together with the identification of several anaerobic microorganisms in oil fields and the discovery of anaerobic hydrocarbon biodegradation mechanisms, suggests that anaerobic degradation processes could also be responsible. The extent of anaerobic hydrocarbon degradation processes in the world's deep petroleum reservoirs, however, remains strongly contested. Moreover, no organism has yet been isolated that has been shown to degrade hydrocarbons under the conditions found in deep petroleum reservoirs. Here we report the isolation of metabolites indicative of anaerobic hydrocarbon degradation from a large fraction of 77 degraded oil samples from both marine and lacustrine sources from around the world, including the volumetrically important Canadian tar sands. Our results therefore suggest that anaerobic hydrocarbon degradation is a common process in biodegraded subsurface oil reservoirs.

  18. Biodegradation of crude oil saturated fraction supported on clays.

    Science.gov (United States)

    Ugochukwu, Uzochukwu C; Jones, Martin D; Head, Ian M; Manning, David A C; Fialips, Claire I

    2014-02-01

    The role of clay minerals in crude oil saturated hydrocarbon removal during biodegradation was investigated in aqueous clay/saturated hydrocarbon microcosm experiments with a hydrocarbon degrading microorganism community. The clay minerals used for this study were montmorillonite, palygorskite, saponite and kaolinite. The clay mineral samples were treated with hydrochloric acid and didecyldimethylammonium bromide to produce acid activated- and organoclays respectively which were used in this study. The production of organoclay was restricted to only montmorillonite and saponite because of their relative high CEC. The study indicated that acid activated clays, organoclays and unmodified kaolinite, were inhibitory to biodegradation of the hydrocarbon saturates. Unmodified saponite was neutral to biodegradation of the hydrocarbon saturates. However, unmodified palygorskite and montmorillonite were stimulatory to biodegradation of the hydrocarbon saturated fraction and appears to do so as a result of the clays' ability to provide high surface area for the accumulation of microbes and nutrients such that the nutrients were within the 'vicinity' of the microbes. Adsorption of the saturated hydrocarbons was not significant during biodegradation.

  19. Polyethylene Modification as Biodegradable Composite Polymer for Packing Materials

    International Nuclear Information System (INIS)

    Deswita; Aloma KK; Sudirman; Indra Gunawan

    2008-01-01

    The synthesis of biodegradable polymer using blending method has been done. The aim of this research is to synthesize kinds of biodegradable composite polymer materials which could be applied in many kinds of requirements such as environmental friendly packaging and degradable. In this paper, the synthetic of biodegradable composite polymer was performed by adding biodegradable filler to the synthetic polymer using blending method. In this experiment Low Linier Density Polyethylene (LLDPE), High Density Polyethylene (HDPE) and filler of tapioca were used. The variation of tapioca meal composition were 50 in weight percent, 55 in weight percent, 60 in weight percent, 65 in weight percent, 70 in weight percent and 75 in weight percent. The characterization was done by means of thermal test, microstructure test, biodegradable and mechanical test. The result showed that the mechanical properties of the materials decreased with increasing composition of tapioca but did not show significant change to the polymer composite materials. For burrying time inside the ground of 8 weeks, all specimens based on polymer LLDPE for all composition of tapioca filler were degraded inside the ground, where as for all specimens based on polymer HDPE with all composition of tapioca filler did not show any degradation. (author)

  20. Microneedles array with biodegradable tips for transdermal drug delivery

    Science.gov (United States)

    Iliescu, Ciprian; Chen, Bangtao; Wei, Jiashen; Tay, Francis E. H.

    2008-12-01

    The paper presented an enhancement solution for transdermal drug delivery using microneedles array with biodegradable tips. The microneedles array was fabricated by using deep reactive ion etching (DRIE) and the biodegradable tips were made to be porous by electrochemical etching process. The porous silicon microneedle tips can greatly enhance the transdermal drug delivery in a minimum invasion, painless, and convenient manner, at the same time; they are breakable and biodegradable. Basically, the main problem of the silicon microneedles consists of broken microneedles tips during the insertion. The solution proposed is to fabricate the microneedle tip from a biodegradable material - porous silicon. The silicon microneedles are fabricated using DRIE notching effect of reflected charges on mask. The process overcomes the difficulty in the undercut control of the tips during the classical isotropic silicon etching process. When the silicon tips were formed, the porous tips were then generated using a classical electrochemical anodization process in MeCN/HF/H2O solution. The paper presents the experimental results of in vitro release of calcein and BSA with animal skins using a microneedle array with biodegradable tips. Compared to the transdermal drug delivery without any enhancer, the microneedle array had presented significant enhancement of drug release.

  1. User’s Guide for Biodegradation Reactions in TMVOCBio

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Yoojin [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Battistelli, Alfredo [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2017-08-31

    TMVOCBio is an extended version of the TMVOC numerical reservoir simulator, with the capability of simulating multiple biodegradation reactions mediated by different microbial populations or based on different redox reactions, thus involving different electron acceptors. This modeling feature is implemented within the existing TMVOC module in iTOUGH2. TMVOCBio, originally developed by Battistelli (2003; 2004), uses a general modified form of the Monod kinetic rate equation to simulate biodegradation reactions, which effectively simulates the uptake of a substrate while accounting for various limiting factors (i.e., the limitation by substrate, electron acceptor, or nutrients). Two approaches are included: 1) a multiple Monod kinetic rate equation, which assumes all the limiting factors simultaneously affect the substrate uptake rate, and 2) a minimum Monod model, which assumes that the substrate uptake rate is controlled by the most limiting factor among those acting for the specific substrate. As the limiting factors, biomass growth inhibition, toxicity effects, as well as competitive and non-competitive inhibition effects are included. The temperature and moisture dependence of biodegradation reactions is also considered. This report provides mathematical formulations and assumptions used for modeling the biodegradation reactions, and describes additional modeling capabilities. Detailed description of input format for biodegradation reactions is presented along with sample problems.

  2. Screening test for assessment of ultimate biodegradability: linear alkylbenzene sulfonates.

    Science.gov (United States)

    Gledhill, W E

    1975-01-01

    A relatively simple shake-flask system for determining CO2 evolution was developed to assess the ultimate biodegradability by soil and sewage micro-organisms of chemicals which enter the environment. Linear alkylbenzene sulfonates (LAS) were used as model compounds to evaluate the method and were found to undergo substantial biodegradation in this dilute system. At the 30 mg/liter test concentration, higher-molecular-weight LAS compounds were biodegraded at a slower rate and to a lesser extent than lower-molecular-weight LAS, an effect which was eliminated or greatly reduced upon incremental addition of the LAS to the test medium during the first week of incubation. LA35S was used to demonstrate rapid LAS desulfonation, and 14CO2 evolution studies with (14C) benzene ring-labeled LAS indicated concomitant biodegradation of the entire LAS molecule as well as the LAS aromatic component. The test can be employed to examine numerous compounds at the same time and is readily adapted to studies of the effect of variation in temperature and oxygen concentration on biodegradation. PMID:1211937

  3. Genetics and alcoholism.

    Science.gov (United States)

    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.

  4. On molybdenum (6) alcoholates

    International Nuclear Information System (INIS)

    Turova, N.Ya.; Kessler, V.G.

    1990-01-01

    Synthesis techniques for molybdenum (6) alcoholates of MoO(OR) 4 (1) and MoO 2 (OR) 2 (2) series by means of exchange interaction of corresponding oxychloride with MOR (M=Li, Na) are obtained. These techniques have allowed to prepare 1(R=Me, Et, i-Pr) and 2(R=Me, Et) with 70-98 % yield. Methylates are also prepared at ether interchange of ethylates by methyl alcohol. Metal anode oxidation in corresponding alcohol may be used for 1 synthesis. Physicochemical properties of both series alcoholates, solubility in alcohols in particular, depend on their formation conditions coordination polymerism. Alcoholates of 1 are rather unstable and tend to decomposition up to 2 and ether. It is suggested to introduce NaOR microquantities to stabilize those alcoholates

  5. Alcohol and atherosclerosis

    DEFF Research Database (Denmark)

    Tolstrup, Janne; Grønbaek, Morten

    2007-01-01

    Light to moderate alcohol intake is known to have cardioprotective properties; however, the magnitude of protection depends on other factors and may be confined to some subsets of the population. This review focuses on factors that modify the relationship between alcohol and coronary heart disease...... (CHD). The cardioprotective effect of alcohol seems to be larger among middle-aged and elderly adults than among young adults, who do not have a net beneficial effect of a light to moderate alcohol intake in terms of reduced all-cause mortality. The levels of alcohol at which the risk of CHD is lowest...... and the levels of alcohol at which the risk of CHD exceeds the risk among abstainers are lower for women than for men. The pattern of drinking seems important for the apparent cardioprotective effect of alcohol, and the risk of CHD is generally lower for steady versus binge drinking. Finally, there is some...

  6. New fungal biomasses for cyanide biodegradation.

    Science.gov (United States)

    Ozel, Yasemin Kevser; Gedikli, Serap; Aytar, Pınar; Unal, Arzu; Yamaç, Mustafa; Cabuk, Ahmet; Kolankaya, Nazif

    2010-10-01

    Cyanide, a hazardous substance, is released into the environment as a result of natural processes of various industrial activities which is a toxic pollutant according to Environmental Protection Agency. In nature, some microorganisms are responsible for the degradation of cyanide, but there is only limited information about the degradation characteristics of Basidiomycetes for cyanide. The aim of the present study is to determine cyanide degradation characteristics in some Basidiomycetes strains including Polyporus arcularius (T 438), Schizophyllum commune (T 701), Clavariadelphus truncatus (T 192), Pleurotus eryngii (M 102), Ganoderma applanatum (M 105), Trametes versicolor (D 22), Cerrena unicolor (D 30), Schizophyllum commune (D 35) and Ganoderma lucidum (D 33). The cyanide degradation activities of P. arcularius S. commune and G. lucidum were found to be more than that of the other fungi examined. The parameters including incubation time, amount of biomass, initial cyanide concentration, temperature, pH and agitation rate were optimized for the selected three potential fungal strains. The maximum cyanide degradation was obtained after 48 h of incubation at 30°C by P. arcularius (T 438). The optimum pH and agitation rate were measured as 10.5 and 150 rev/min, respectively. The amount of biomass was found as 3.0 g for the maximum cyanide biodegradation with an initial cyanide concentration of 100mg/L. In this study, agar was chosen entrapment agent for the immobilization of effective biomass. We suggested that P. arcularius (T 438) could be effective in the treatment of contaminated sites with cyanide due to capability of degrading cyanide. Copyright © 2010 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  7. Biodegradable Polymers in Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Leon E. Govaert

    2009-07-01

    Full Text Available The use ofdegradable polymers in medicine largely started around the mid 20th century with their initial use as in vivo resorbing sutures. Thorough knowledge on this topic as been gained since then and the potential applications for these polymers were, and still are, rapidly expanding. After improving the properties of lactic acid-based polymers, these were no longer studied only from a scientific point of view, but also for their use in bone surgery in the 1990s. Unfortunately, after implanting these polymers, different foreign body reactions ranging from the presence of white blood cells to sterile sinuses with resorption of the original tissue were observed. This led to the misconception that degradable polymers would, in all cases, lead to inflammation and/or osteolysis at the implantation site. Nowadays, we have accumulated substantial knowledge on the issue of biocompatibility of biodegradable polymers and are able to tailor these polymers for specific applications and thereby strongly reduce the occurrence of adverse tissue reactions. However, the major issue of biofunctionality, when mechanical adaptation is taken into account, has hitherto been largely unrecognized. A thorough understanding of how to improve the biofunctionality, comprising biomechanical stability, but also visualization and sterilization of the material, together with the avoidance of fibrotic tissue formation and foreign body reactions, may greatly enhance the applicability and safety of degradable polymers in a wide area of tissue engineering applications. This review will address our current understanding of these biofunctionality factors, and will subsequently discuss the pitfalls remaining and potential solutions to solve these problems.

  8. Effects of lag and maximum growth in contaminant transport and biodegradation modeling

    International Nuclear Information System (INIS)

    Wood, B.D.; Dawson, C.N.

    1992-06-01

    The effects of time lag and maximum microbial growth on biodegradation in contaminant transport are discussed. A mathematical model is formulated that accounts for these effects, and a numerical case study is presented that demonstrates how lag influences biodegradation

  9. Environmental biodegradation of haloarchaea-produced poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in activated sludge

    DEFF Research Database (Denmark)

    Liu, Xiao-Bin; Wu, Linping; Hou, Jing

    2016-01-01

    Novel poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) copolymers produced by haloarchaea are excellent candidate biomaterials. However, there is no report hitherto focusing on the biodegradation of PHBHV synthesized by haloarchaea. In this study, an environmental biodegradation of haloarchae...

  10. Preparation of porous structures with shape memory properties from biodegradable polymeric networks

    NARCIS (Netherlands)

    Sharifi, Shahriar; Blanquer, Sebastien; Grijpma, Dirk W.

    2012-01-01

    Preparing porous biodegradable structures from shape memory polymers can combine the structure-defining properties of porous structures with the minimally invasive implanting possibilities of shape memory polymers. In this study, porous biodegradable shape memory structures were prepared using

  11. Biodegradation: Updating the Concepts of Control for Microbial Cleanup in Contaminated Aquifers

    DEFF Research Database (Denmark)

    Meckenstock, Rainer U.; Elsner, Martin; Griebler, Christian

    2015-01-01

    critically discuss classical concepts such as the thermodynamic redox zonation, or the use of steady state transport scenarios for assessing biodegradation rates. Furthermore, we discuss if the absence of specific degrader populations can explain poor biodegradation. We propose updated perspectives...

  12. Alcohol Abuse and Other Psychiatric Disorders

    Science.gov (United States)

    Skip to main content National Institute on Alcohol Abuse and Alcoholism (NIAAA) Main Menu Search Search form Search Alcohol & Your Health Overview of Alcohol Consumption Alcohol's Effects on the Body Alcohol ...

  13. Covalent chemical functionalization enhances the biodegradation of graphene oxide

    Science.gov (United States)

    Kurapati, Rajendra; Bonachera, Fanny; Russier, Julie; Rajukrishnan Sureshbabu, Adukamparai; Ménard-Moyon, Cécilia; Kostarelos, Kostas; Bianco, Alberto

    2018-01-01

    Biodegradation of the graphene-based materials is an emerging issue due to their estimated widespread usage in different industries. Indeed, a few concerns have been raised about their biopersistence. Here, we propose the design of surface-functionalized graphene oxide (GO) with the capacity to degrade more effectively compared to unmodified GO using horseradish peroxidase (HRP). For this purpose, we have functionalized the surface of GO with two well-known substrates of HRP namely coumarin and catechol. The biodegradation of all conjugates has been followed by Raman, dynamic light scattering and electron microscopy. Molecular docking and gel electrophoresis have been carried out to gain more insights into the interaction between GO conjugates and HRP. Our studies have revealed better binding when GO is functionalized with coumarin or catechol compared to control GOs. All results prove that GO functionalized with coumarin and catechol moieties display a faster and more efficient biodegradation over GO.

  14. Synthetic biodegradable functional polymers for tissue engineering: a brief review.

    Science.gov (United States)

    BaoLin, Guo; Ma, Peter X

    2014-04-01

    Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly (glycerol sebacate) are summarized in this article. New developments in conducting polymers, photoresponsive polymers, amino-acid-based polymers, enzymatically degradable polymers, and peptide-activated polymers are also discussed. In addition to chemical functionalization, the scaffold designs that mimic the nano and micro features of the extracellular matrix (ECM) are presented as well, and composite and nanocomposite scaffolds are also reviewed.

  15. Modeling cutinase enzyme regulation in polyethylene terepthalate plastic biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Apri, M., E-mail: m.apri@math.itb.ac.id; Silmi, M. [Department of Mathematics, Institut Teknologi Bandung, Jalan Ganeca 10 Bandung, 40132 (Indonesia); Heryanto, T. E.; Moeis, M. R. [School of Life Sciences and Technology, Institut Teknologi Bandung, Jalan Ganeca 10 Bandung, 40132 (Indonesia)

    2016-04-06

    PET (Polyethylene terephthalate) is a plastic material that is commonly used in our daily life. The high production of PET and others plastics that can be up to three hundred million tons per year, is not matched by its degradation rate and hence leads to environmental pollution. To overcome this problem, we develop a biodegradation system. This system utilizes LC Cutinase enzyme produced by engineered escherichia coli bacteria to degrade PET. To make the system works efficaciously, it is important to understand the mechanism underlying its enzyme regulation. Therefore, we construct a mathematical model to describe the regulation of LC Cutinase production. The stability of the model is analyzed. We show that the designated biodegradation system can give an oscillatory behavior that is very important to control the amount of inclusion body (the miss-folded proteins that reduce the efficiency of the biodegradation system).

  16. Ultimate biodegradation of 2-, 3- and 4-nitrotoluene.

    Science.gov (United States)

    Struijs, J; Stoltenkamp, J

    1986-12-01

    The biodegradation of 2-, 3- and 4-nitrotoluene was investigated in a simple laboratory test. All three isomers are shown to be biodegradable in a die-away test after adaptation of the inoculum, though different results were obtained with different types of activated sludges used as inoculum in the static test. The adaptation procedure, employed in this study, was a modification of a test method described by Pitter in 1976. It appeared that adaptation in a semi-continuous activated sludge system was most successful when a composite sludge was used consisting of activated sludge from a communal sewage plant and an extract of river mud. meta-Nitrotoluene was more resistant to attack by a mixed population of aquatic micro-organisms than the other isomers. The procedure used in this study is proposed as an attractive alternative for those methods which are recommended by the OECD and the EEC, to test the so-called 'inherent biodegradability'.

  17. Modeling cutinase enzyme regulation in polyethylene terepthalate plastic biodegradation

    Science.gov (United States)

    Apri, M.; Silmi, M.; Heryanto, T. E.; Moeis, M. R.

    2016-04-01

    PET (Polyethylene terephthalate) is a plastic material that is commonly used in our daily life. The high production of PET and others plastics that can be up to three hundred million tons per year, is not matched by its degradation rate and hence leads to environmental pollution. To overcome this problem, we develop a biodegradation system. This system utilizes LC Cutinase enzyme produced by engineered escherichia coli bacteria to degrade PET. To make the system works efficaciously, it is important to understand the mechanism underlying its enzyme regulation. Therefore, we construct a mathematical model to describe the regulation of LC Cutinase production. The stability of the model is analyzed. We show that the designated biodegradation system can give an oscillatory behavior that is very important to control the amount of inclusion body (the miss-folded proteins that reduce the efficiency of the biodegradation system).

  18. Modeling cutinase enzyme regulation in polyethylene terepthalate plastic biodegradation

    International Nuclear Information System (INIS)

    Apri, M.; Silmi, M.; Heryanto, T. E.; Moeis, M. R.

    2016-01-01

    PET (Polyethylene terephthalate) is a plastic material that is commonly used in our daily life. The high production of PET and others plastics that can be up to three hundred million tons per year, is not matched by its degradation rate and hence leads to environmental pollution. To overcome this problem, we develop a biodegradation system. This system utilizes LC Cutinase enzyme produced by engineered escherichia coli bacteria to degrade PET. To make the system works efficaciously, it is important to understand the mechanism underlying its enzyme regulation. Therefore, we construct a mathematical model to describe the regulation of LC Cutinase production. The stability of the model is analyzed. We show that the designated biodegradation system can give an oscillatory behavior that is very important to control the amount of inclusion body (the miss-folded proteins that reduce the efficiency of the biodegradation system).

  19. Biodegradation of petroleum oil by certain bacterial strains

    International Nuclear Information System (INIS)

    Zakaria, A.E.M.

    1998-01-01

    Balaeam base oil was chosen as a model oil in the present study through which some abiotic treatments were implemented aiming at attenuating its naphthenic and aromatic contents; such as the adsorptive technique and the gamma-irradiation technique . In an attempt to apply the biodegrading bacteria as oil pollutant bio indicators upon coastal water samples, a correlation between hydrocarbon concentration and the relative enumeration of the bacterial oil degraders was detected for some litter locations along the mediterranean Sea shore west and east Delta, Suez canal. and suez gulf. 24 petroleum utilizing bacterial isolates were isolated from El-Zayteia port (suez) and identified by morphological, physiological and environmental examination . the biodegradation capacity of the isolates towards the chosen model oil and its separate components was studied in comparison with the standard isolate pseudomonas aeruginosa. Further, the role of the bacterial plasmids taking part in the biodegradation process was investigated as well

  20. [Biodegradable ureteral stents in treating patients with infravesical obstruction].

    Science.gov (United States)

    Chepurov, A K; Krivoborodov, G G; Zubarev, A V; Zaĭtsev, N V; Markina, N Iu

    2003-01-01

    Biodegradable endoprostheses SR-PLGA and SR-PLLA were used in combined treatment of 39 patients with urethral stricture (n = 24), neurogenic urinary bladder (n = 9), benign prostatic hyperplasia (n = 4), prostatic cancer (n = 2). In definition of indications for stent implantation the leading role was assigned to preoperative diagnosis of the state of the urinary bladder, urethra and sphincters using urodynamic tests and dynamic Doppler and three-dimensional echourethrography. Introduction of biodegradable urethral stents provides adequate spontaneous urination and allows avoiding external drainage. This prevents nosocomial infection and lowers the number of inflammatory complications. Palliative usage of stents in inoperable and neurological patients is effective in their medical and social rehabilitation. Analysis of errors and complications in 8 patients demonstrates that implantation of biodegradable stents is not absolute safe and requires some caution.

  1. The freshwater biodegradation potential of nine Alaskan oils

    International Nuclear Information System (INIS)

    Blenkinsopp, S.; Segy, G.

    1997-01-01

    Nine Alaskan representative crude oils and oil products with freshwater spill potential were collected, aged, and incubated in the presence of the standard freshwater inoculum for 28 days at 10 degrees C. Detailed analytical chemistry was performed on all samples to quantify compositional changes. All of the samples tested exhibited measurable hydrocarbon loss as a result of incubation with the freshwater inoculum. Total saturate and total n-alkane biodegradation were greatly enhanced when nutrients were present. The oil products Jet B Fuel and Diesel No. 2 appear to be more biodegradable than the Alaska North Slope and Cook Inlet crude oils tested, while the Bunker C/Diesel mixture appears to be less biodegradable than these crude oils. These results suggest that the screening procedures described here can provide useful information when applying bioremediation technology to the cleanup of selected oiled freshwater environments. 10 refs., 5 tabs., 13 figs

  2. DEVELOPMENT OF ACTIVE AND BIODEGRADABLES CONTAINERS FOR AGRICULTURAL CROPS

    Directory of Open Access Journals (Sweden)

    Franco Poggio

    2016-06-01

    Full Text Available In this paper, the development of biodegradable containers for crops that could be transplanted directly and act as fertilizers is proposed. Bovine gelatin was chosen as the base material, which was processed in a mini-injector mixer with a concentrated urea solution acted as a plasticizer. Rheological and tensile tests were performed in order to evaluate the injection of gelatin based formulations and mechanical properties related to the proposed application. Taking into account that biodegradable materials have a low water resistance, the increment of container stability was proposed using a surface coating. In addition, the influence of moisture content, the soluble matter and swelling were studied and analyzed. It was observed that coated samples were significantly more stable than the control ones, which guarantees the feasibility of the selected system and its potential development of biodegradable containers.

  3. Biodegradation of diesel/biodiesel blends in saturated sand microcosms

    DEFF Research Database (Denmark)

    Lisiecki, Piotr; Chrzanowski, Łukasz; Szulc, Alicja

    2014-01-01

    is commercial biodiesel blend) augmented with a bacterial consortium of petroleum degraders. The biodegradation kinetics for blends were evaluated based on measuring the amount of emitted CO2 after 578 days. Subsequently, the residual aromatic and aliphatic fractions were separated and determined by employing......The aim of the study was to evaluate the biodegradation extent of both aromatic and aliphatic hydrocarbon fractions in saturated sandy microcosm spiked with diesel/biodiesel blends (D, B10, B20, B30, B40, B50, B60, B70, B80, B90 and B100, where D is commercial petroleum diesel fuel and B...... GC-FID and GC _ GC–TOF-MS. Additionally, the influence of biodiesel-amendment on the community dynamics was assessed based on the results of real-time PCR analyzes. Our results suggest that the biodegradation extents of both aliphatic and aromatic hydrocarbon were uninfluenced by the addition...

  4. Biodegradation of creosote compounds: Comparison of experiments at different scales

    DEFF Research Database (Denmark)

    Broholm, K.; Arvin, Erik

    2001-01-01

    This paper compares the results of biodegradation experiments with creosote compounds performed at different scales. The experiments include field observations, field experiments, large-scale intact laboratory column experiments, model fracture experiments, and batch experiments. Most of the expe......This paper compares the results of biodegradation experiments with creosote compounds performed at different scales. The experiments include field observations, field experiments, large-scale intact laboratory column experiments, model fracture experiments, and batch experiments. Most...... of the experiments were conducted with till or ground water from the field site at Ringe on the island of Funen. Although the experiments were conducted on different scales, they revealed that some phenomena-e.g., an extensive biodegradation potential of several of the creosote compounds, the inhibitory influence...

  5. Veratryl alcohol oxidases from the lignin-degrading basidiomycete Pleurotus sajor-caju.

    Science.gov (United States)

    Bourbonnais, R; Paice, M G

    1988-01-01

    The basidiomycete Pleurotus sajor-caju mineralizes ring-14C-labelled lignin (dehydrogenative polymer) when grown in mycological broth. Under these conditions, two veratryl alcohol oxidase (VAO) enzymes were found in the culture medium. They oxidized a number of aromatic alcohols to aldehydes and reduced O2 to H2O2. The enzymes were purified by ion-exchange and gel-permeation chromatography. The final step of purification on Mono Q resolved the activity into two peaks (VAO I and VAO II). Both enzymes had the same Mr, approx. 71,000, but their isoelectric points differed slightly, 3.8 for VAO I and 4.0 for VAO II. Their amino acid compositions were similar except for aspartic acid/asparagine and glycine. Both enzymes are glycoproteins and contain flavin prosthetic groups. Their pH optima were around 5, and kinetic constants and specificities were similar. 4-Methoxybenzyl alcohol was oxidized the most rapidly, followed by veratryl alcohol. Not all aromatic alcohols were oxidized, neither were non-aromatic alcohols. Cinnamyl alcohol was oxidized at the gamma position. The VAO enzymes thus represent a significantly different route for veratryl alcohol oxidation from that catalysed by the previously found lignin peroxidases from Phanerochaete chrysosporium. The role of the oxidases in biodegradation might be to produce H2O2 during oxidation of lignin fragments. Images Fig. 3. PMID:3060110

  6. Biodegradation: Updating the Concepts of Control for Microbial Cleanup in Contaminated Aquifers

    DEFF Research Database (Denmark)

    Meckenstock, Rainer U.; Elsner, Martin; Griebler, Christian

    2015-01-01

    critically discuss classical concepts such as the thermodynamic redox zonation, or the use of steady state transport scenarios for assessing biodegradation rates. Furthermore, we discuss if the absence of specific degrader populations can explain poor biodegradation. We propose updated perspectives...... on the controls of biodegradation in contaminant plumes. These include the plume fringe concept, transport limitations, and transient conditions as currently underestimated processes affecting biodegradation....

  7. Evaluation of vadose zone biodegradation of BTX vapours

    Science.gov (United States)

    Hers, Ian; Atwater, Jim; Li, Loretta; Zapf-Gilje, Reidar

    2000-12-01

    Soil vapour transport to indoor air is an important potential exposure pathway at many sites impacted by subsurface volatile organic compounds (VOCs). The inclusion of biodegradation in vadose zone transport models for benzene, toluene and xylene (BTX) and fuel hydrocarbons has been proposed; however, there is still significant uncertainty regarding biodegradation rates and the local effects of buildings or ground surface cover on fate and transport processes. The objective of this study was to evaluate biodegradation processes through comprehensive monitoring at a site contaminated with BTX and model simulation. Study methods included extensive vertical profiling of BTX vapour and light gas (oxygen and carbon dioxide) concentrations and moisture content, and semi-continuous monitoring of oxygen and pressure below a building floor slab. Significant vadose zone biodegradation over a relatively small depth interval was observed. Based on the observed soil vapour profile, first-order biodegradation rates were estimated by fitting an analytical solution for diffusion and biodecay to the data. Degradation rates were found to compare well to other reported laboratory and field data. A two-dimensional (2-D) numerical model incorporating vapour-phase diffusion, advection, sorption and biodegradation was used to simulate the effect of a building floor slab on transport processes. Model results demonstrate the sensitivity of vapour-phase BTX and oxygen transport to partial barriers to diffusion (e.g. building foundation) and highlight the importance of using a model that ties biodecay to oxygen availability. In addition, depressurization within a building and advective transport is shown to have a potentially significant effect on BTX fate, in soil below.

  8. Biodegradation of concrete intended for their decontamination; Biodegradation de matrices cimentaires en vue de leur decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Jestin, A

    2005-05-15

    The decontamination of sub-structural materials represents a stake of high importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those microorganisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

  9. Biodegradability engineering of biodegradable Mg alloys: Tailoring the electrochemical properties and microstructure of constituent phases

    Science.gov (United States)

    Cha, Pil-Ryung; Han, Hyung-Seop; Yang, Gui-Fu; Kim, Yu-Chan; Hong, Ki-Ha; Lee, Seung-Cheol; Jung, Jae-Young; Ahn, Jae-Pyeong; Kim, Young-Yul; Cho, Sung-Youn; Byun, Ji Young; Lee, Kang-Sik; Yang, Seok-Jo; Seok, Hyun-Kwang

    2013-01-01

    Crystalline Mg-based alloys with a distinct reduction in hydrogen evolution were prepared through both electrochemical and microstructural engineering of the constituent phases. The addition of Zn to Mg-Ca alloy modified the corrosion potentials of two constituent phases (Mg + Mg2Ca), which prevented the formation of a galvanic circuit and achieved a comparable corrosion rate to high purity Mg. Furthermore, effective grain refinement induced by the extrusion allowed the achievement of much lower corrosion rate than high purity Mg. Animal studies confirmed the large reduction in hydrogen evolution and revealed good tissue compatibility with increased bone deposition around the newly developed Mg alloy implants. Thus, high strength Mg-Ca-Zn alloys with medically acceptable corrosion rate were developed and showed great potential for use in a new generation of biodegradable implants. PMID:23917705

  10. Alcohol and pregnancy

    Directory of Open Access Journals (Sweden)

    Anna Maria Paoletti

    2013-06-01

    Full Text Available Alcohol exerts teratogenic effects in all the gestation times, with peculiar features in relationship to the trimester of pregnancy in which alcohol is assumed. Alcohol itself and its metabolites modify DNA synthesis, cellular division, cellular migration and the fetal development. The characteristic facies of feto-alcoholic syndrome (FAS-affected baby depends on the alcohol impact on skull facial development during the first trimester of pregnancy. In association there are cerebral damages with a strong defect of brain development up to the life incompatibility. Serious consequences on fetal health also depends on dangerous effects of alcohol exposure in the organogenesis of the heart, the bone, the kidney, sensorial organs, et al. It has been demonstrated that maternal binge drinking is a high factor risk of mental retardation and of delinquent behaviour. Unfortunately, a lower alcohol intake also exerts deleterious effects on fetal health. In several countries of the world there is a high alcohol use, and this habit is increased in the women. Therefore, correct information has to be given to avoid alcohol use by women in the preconceptional time and during the pregnancy. Preliminary results of a study performed by the authors show that over 80% of pregnant and puerperal women are not unaware that more than 2 glasses of alcohol/week ingested during pregnancy can create neurological abnormalities in the fetus. However, after the information provided on alcoholic fetopathy, all women are conscious of the damage caused by the use of alcohol to the fetus during pregnancy. This study confirms the need to provide detailed information on the negative effects of alcohol on fetal health. Proceedings of the 9th International Workshop on Neonatology · Cagliari (Italy · October 23rd-26th, 2013 · Learned lessons, changing practice and cutting-edge research

  11. Soil Quality and Colloid Transport under Biodegradable Mulches

    Science.gov (United States)

    Sintim, Henry; Bandopadhyay, Sreejata; Ghimire, Shuresh; Flury, Markus; Bary, Andy; Schaeffer, Sean; DeBruyn, Jennifer; Miles, Carol; Inglis, Debra

    2016-04-01

    Polyethylene (PE) mulch is commonly used in agriculture to increase water use efficiency, to control weeds, manage plant diseases, and maintain a favorable micro-climate for plant growth. However, producers need to retrieve and safely dispose PE mulch after usage, which creates enormous amounts of plastic waste. Substituting PE mulch with biodegradable plastic mulches could alleviate disposal needs. However, repeated applications of biodegradable mulches, which are incorporated into the soil after the growing season, may cause deterioration of soil quality through breakdown of mulches into colloidal fragments, which can be transported through soil. Findings from year 1 of a 5-year field experiment will be presented.

  12. DNA polyplexes formed using PEGylated biodegradable hyperbranched polymers.

    Science.gov (United States)

    Tao, Lei; Chou, William C; Tan, Beng H; Davis, Thomas P

    2010-06-11

    A novel PEGylated biodegradable hyperbranched PEG-b-PDMAEMA has been synthesized. The low toxicity, small molecular weight PDMAEMA chains were crosslinked using a biodegradable disulfide-based dimethacrylate (DSDMA) agent to yield higher molecular weight hyperbranched polymers. PEG chains were linked onto the polymer surface, masking the positive charge (as shown by Zeta potential measurements) and reducing the toxicity of the polymer. The hyperbranched structures were also cleaved under reducing conditions and analyzed, confirming the expected component structures. The hyperbranched polymer was mixed with DNA and efficient binding was shown to occur through electrostatic interactions. The hyperbranched structures could be reduced easily, generating lower toxicity oligomer chains.

  13. Application of a Biodegradable Lubricant in a Diesel Vehicle

    DEFF Research Database (Denmark)

    Schramm, Jesper

    2003-01-01

    The IEA Advanced Motor Fuels Agreement has initiated this project concerning the application of biodegradable lubricants to diesel and gasoline type vehicles. Emission measurements on a chassis dynamometer were carried out. The purpose of these measurements was to compare the emissions of CO, CO2......, NOx, THC, PM, lubricant-SOF and PAH from one diesel and one gasoline type vehicle using biodegradable lubricants and conventional lubricants. This paper describes the results of the experiments with the diesel type vehicle only. Lubricant consumption and fuel consumption are other important parameters...

  14. Cementation of biodegraded radioactive oils and organic waste

    International Nuclear Information System (INIS)

    Olga Gorbunova; Russian Academy of Sciences, Moscow; Aleksey Safonov; Varvara Tregubova; Konstantin German

    2015-01-01

    Microbiological pre-treatment of the oil-containing organic liquid radioactive waste (LRW) before its solidification into cement matrix (CM) has been investigated and shown to be efficient. Biodegradation of the oil containing LRW is possible by using the microflora, which oxidize the organic components of the oil to carbon dioxide, water and different oxo-organic compounds, sorb radionuclides and cause emulsification of oil in cement slurry due to biogenic surface-active substances, improving the mixing ability of the LRWCM. Here we present the biotechnological parameters of biodegradation and cementation, and the physical-chemical properties of the final LRWCM. (author)

  15. Biodegradation in oils as a geological natural analogue

    International Nuclear Information System (INIS)

    Rojas, G.; Julio Salvarredi, J.

    2004-01-01

    A synthesis of scientific knowledge about petroleum biodegradation linked to uranium mineralisation is firstly done. Then the genesis of Huemul Uranium ore deposit (Malargue Town, Mendoza Province) is discussed, where Uranium ore is linked only with one type of asphaltite (there are three other types) from an oil field close by. This asphaltite type would be an efficient natural geological barrier for Uranium migration and it could be linked to a particular kind of biodegradation. The authors think that the International Wonuc Conference would be a good opportunity to discuss a way for future investigations. (author)

  16. Method of increasing biodegradation of sparingly soluble vapors

    Science.gov (United States)

    Cherry, Robert S.

    2000-01-01

    A method for increasing biodegradation of sparingly soluble volatile organic compounds (VOCs) in a bioreactor is disclosed. The method comprises dissolving in the aqueous phase of the bioreactor a water soluble, nontoxic, non-biodegradable polymer having a molecular weight of at least 500 and operable for decreasing the distribution coefficient of the VOCs. Polyoxyalkylene alkanols are preferred polymers. A method of increasing the growth rate of VOC-degrading microorganisms in the bioreactor and a method of increasing the solubility of sparingly soluble VOCs in aqueous solution are also disclosed.

  17. Biodegradation of Jet Fuel in Vented Columns of Water-Unsaturated Sandy Soil

    Science.gov (United States)

    1990-01-01

    photodegradation , volatilization and microbial degradation; however, microbial degradation is the most significant process by which many pesticides are degraded...Biodegradation . 12 Soil Water Content and Pesticide Biodegradation ... ............. . 16 Aeration . . . . . . ................. 18 Soil Venting and... Pesticide Biodegradation While petroleum hydrocarbons and pesticides may differ considerably in chemical composition and structure, they share at least

  18. Effect of Material Parameters on Mechanical Properties of Biodegradable Polymers/Nanofibrillated Cellulose (NFC) Nano Composites

    Science.gov (United States)

    Yottha Srithep; Ronald Sabo; Craig Clemons; Lih-Sheng Turng; Srikanth Pilla; Jun Peng

    2012-01-01

    Using natural cellulosic fibers as fillers for biodegradable polymers can result in fully biodegradable composites. Biodegradable composites were prepared using nanofibrillated cellulose (NFC) as the reinforcement and poly (3-hydroxybutyrate-co-3-hydroxyvalerate, PHBV) as the polymer matrix. The objective of this study was to determine how various additives (i.e.,...

  19. Diagnosis of alcohol misuse and alcoholic liver disease among ...

    African Journals Online (AJOL)

    Introduction: Uganda is among the top ten consumers of alcohol worldwide though there is little data on alcohol related liver disease. We describe alcohol use, alcohol misuse, and alcoholic liver disease among adults at the emergency admission service of a large urban hospital in Uganda. Methods: All adults who ...

  20. Mechanical characterization of commercial biodegradable plastic films

    Science.gov (United States)

    Vanstrom, Joseph R.

    Polylactic acid (PLA) is a biodegradable plastic that is relatively new compared to other plastics in use throughout industry. The material is produced by the polymerization of lactic acid which is produced by the fermentation of starches derived from renewable feedstocks such as corn. Polylactic acid can be manufactured to fit a wide variety of applications. This study details the mechanical and morphological properties of selected commercially available PLA film products. Testing was conducted at Iowa State University and in conjunction with the United States Department of Agriculture (USDA) BioPreferred ProgramRTM. Results acquired by Iowa State were compared to a similar study performed by the Cortec Corporation in 2006. The PLA films tested at Iowa State were acquired in 2009 and 2010. In addition to these two studies at ISU, the films that were acquired in 2009 were aged for a year in a controlled environment and then re-tested to determine effects of time (ageing) on the mechanical properties. All films displayed anisotropic properties which were confirmed by inspection of the films with polarized light. The mechanical testing of the films followed American Society for Testing and Materials (ASTM) standards. Mechanical characteristics included: tensile strength (ASTM D882), elongation of material at failure (ASTM D882), impact resistance (ASTM D1922), and tear resistance (ASTM D4272). The observed values amongst all the films ranged as followed: tensile strength 33.65--8.54 MPa; elongation at failure 1,665.1%--47.2%; tear resistance 3.61--0.46 N; and puncture resistance 2.22--0.28 J. There were significant differences between the observed data for a number of films and the reported data published by the Cortec Corp. In addition, there were significant differences between the newly acquired material from 2009 and 2010, as well as the newly acquired materials in 2009 and the aged 2009 materials, suggesting that ageing and manufacturing date had an effect on

  1. Alcohol use among adolescents.

    Science.gov (United States)

    O'Malley, P M; Johnston, L D; Bachman, J G

    1998-01-01

    Several ongoing national surveys, including the Monitoring the Future study, the National Household Survey on Drug Abuse, and the Youth Risk Behavior Survey, are investigating the drinking behaviors of adolescents in the United States. These studies have found that the majority of adolescents under the age of 18 have consumed alcohol, although the minimum legal drinking age is 21. Drinking rates may even have increased in recent years in some age groups. No substantial differences exist among various sociodemographic subgroups with respect to drinking rates, although alcohol consumption generally is lowest among African-Americans and highest among whites. Moreover, alcohol consumption increases sharply throughout adolescence. Various attitudinal and behavioral factors, such as religious involvement, truancy, and average grade level, also influence adolescents' drinking behaviors. Almost two-thirds of 12th graders who report consuming alcohol experience at least one alcohol-related problem. Most adolescents drink to experience the pleasurable effects of alcohol, such as having a good time with friends.

  2. Alcohol, aggression, and violence

    Directory of Open Access Journals (Sweden)

    Darja Škrila

    2005-09-01

    Full Text Available Background: The association between alcohol and aggression has long been recognized, but the systematic research to understand the causal basis for this relationship and the processes that underlie it has only been undertaken in the past 25 years. In the article the most important mechanisms, by which alcohol affects behavior, are explained. Aggression in persons with alcohol dependence and the connection between antisocial (dissocial personality disorder, alcohol and aggression are described. In addition different forms of aggression or violence, that have been committed under the influence of alcohol, such as inter-partner violence, sexual assault, child abuse, crime and traffic accidents are described.Conclusions: The research findings can be used in the prevention and treatment of alcohol-related aggression.

  3. Attendance at alcohol-free and alcohol-service parties and alcohol consumption among college students.

    Science.gov (United States)

    Wei, Jill; Barnett, Nancy P; Clark, Melissa

    2010-06-01

    To examine attendance at alcohol-service and alcohol-free parties among college students, and to compare alcohol consumption on nights of these parties. A random sample of 556 students (38.6% male) completed a web survey that measured past-semester alcohol use, alcohol-service party attendance, alcohol-free party attendance, and alcohol consumed on the nights of recent parties. Participants were twice as likely to attend alcohol-service parties as they were to attend alcohol-free parties (90% vs. 44%). First-year students and Black students were more likely than other students to attend alcohol-free parties. Alcohol use was higher in students who attended alcohol-service parties but there were no differences in levels of alcohol use between students who attended alcohol-free parties and those who did not. Pre-gaming was more prevalent, but the number of drinks and intoxication were lower on nights of alcohol-free parties than on nights of alcohol-service parties. The lack of association between attendance at alcohol-free parties and alcohol use indicates both heavy and light drinkers attend these parties. The lower drinking and intoxication on alcohol-free party nights suggests alcohol-free programming should be investigated to determine if it may reduce alcohol use on college campuses. Copyright 2010 Elsevier Ltd. All rights reserved.

  4. [Toxic alcohol poisonings].

    Science.gov (United States)

    Kulicki, Paweł; Głogowski, Tomasz

    Accidental or intentional poisonings with ethylene glycol or methanol constitute a serious toxicological problem in many countries. Both alcohols are quickly metabolized by alcohol dehydrogenase to toxic metabolites responsible for high anion gap severe metabolic acidosis and profound neurological, cardiopulmonary, renal disturbances and death. In the early period, the competing inhibition the alcohol dehydrogenase with ethanol or fomepizol may successfully prevent the formation of the toxic metabolites. Once severe acidosis develops an emergency hemodialysis is required.

  5. Alcohol-Induced Blackout

    Directory of Open Access Journals (Sweden)

    Dai Jin Kim

    2009-11-01

    Full Text Available For a long time, alcohol was thought to exert a general depressant effect on the central nervous system (CNS. However, currently the consensus is that specific regions of the brain are selectively vulnerable to the acute effects of alcohol. An alcohol-induced blackout is the classic example; the subject is temporarily unable to form new long-term memories while relatively maintaining other skills such as talking or even driving. A recent study showed that alcohol can cause retrograde memory impairment, that is, blackouts due to retrieval impairments as well as those due to deficits in encoding. Alcoholic blackouts may be complete (en bloc or partial (fragmentary depending on severity of memory impairment. In fragmentary blackouts, cueing often aids recall. Memory impairment during acute intoxication involves dysfunction of episodic memory, a type of memory encoded with spatial and social context. Recent studies have shown that there are multiple memory systems supported by discrete brain regions, and the acute effects of alcohol on learning and memory may result from alteration of the hippocampus and related structures on a cellular level. A rapid increase in blood alcohol concentration (BAC is most consistently associated with the likelihood of a blackout. However, not all subjects experience blackouts, implying that genetic factors play a role in determining CNS vulnerability to the effects of alcohol. This factor may predispose an individual to alcoholism, as altered memory function during intoxication may affect an individual‟s alcohol expectancy; one may perceive positive aspects of intoxication while unintentionally ignoring the negative aspects. Extensive research on memory and learning as well as findings related to the acute effects of alcohol on the brain may elucidate the mechanisms and impact associated with the alcohol- induced blackout.

  6. Affordability of alcohol and alcohol-related mortality in Belarus.

    Science.gov (United States)

    Razvodovsky, Yury E

    2013-01-01

    Alcohol abuse has numerous adverse health and social consequences. The consumer response to changes in alcohol affordability is an important issue on alcohol policy debates. Studies from many countries have shown an inverse relationship between alcohol prices and alcohol consumption in the population. There are, however, suggestions that increasing the price of alcohol by rising taxes may have limited effect on alcohol-related problems, associated with long-term heavy drinking. The aim of the present study was to evaluate the relationship between alcohol affordability and alcohol-related mortality rates in post-Soviet Belarus. For this purpose trends in alcohol-related mortality rates (mortality from liver cirrhosis, pancreatitis, alcoholism and alcohol psychoses) and affordability of vodka between 1990 and 2010 were compared. The time series analysis revealed that 1% increase in vodka affordability is associated with an increase in liver cirrhosis mortality of 0,77%, an increase in pancreatitis mortality of 0.53%, an increase in mortality from alcoholism and alcohol psychoses of 0,70%. The major conclusion emerging from this study is that affordability of alcohol is one of the most important predictor of alcohol-related problems in a population. These findings provide additional evidence that decreasing in affordability of alcohol is an effective strategy for reducing alcohol consumption and alcohol-related harm.

  7. Effect of chemical heterogeneity of biodegradable polymers on surface energy: A static contact angle analysis of polyester model films.

    Science.gov (United States)

    Belibel, R; Avramoglou, T; Garcia, A; Barbaud, C; Mora, L

    2016-02-01

    Biodegradable and bioassimilable poly((R,S)-3,3 dimethylmalic acid) (PDMMLA) derivatives were synthesized and characterized in order to develop a new coating for coronary endoprosthesis enabling the reduction of restenosis. The PDMMLA was chemically modified to form different custom groups in its side chain. Three side groups were chosen: the hexyl group for its hydrophobic nature, the carboxylic acid and alcohol groups for their acid and neutral hydrophilic character, respectively. The sessile drop method was applied to characterize the wettability of biodegradable polymer film coatings. Surface energy and components were calculated. The van Oss approach helped reach not only the dispersive and polar acid-base components of surface energy but also acid and basic components. Surface topography was quantified by atomic force microscopy (AFM) and subnanometer average values of roughness (Ra) were obtained for all the analyzed surfaces. Thus, roughness was considered to have a negligible effect on wettability measurements. In contrast, heterogeneous surfaces had to be corrected by the Cassie-Baxter equation for copolymers (10/90, 20/80 and 30/70). The impact of this correction was quantified for all the wettability parameters. Very high relative corrections (%) were found, reaching 100% for energies and 30% for contact angles. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Effect of chemical heterogeneity of biodegradable polymers on surface energy: A static contact angle analysis of polyester model films

    Energy Technology Data Exchange (ETDEWEB)

    Belibel, R.; Avramoglou, T. [INSERM U1148, Laboratory for Vascular Translational Science (LVTS), Institut Galilée, Université Paris 13, Sorbonne Paris Cité, 99 Avenue Jean-Baptiste Clément, Villetaneuse F-93430 (France); Garcia, A. [CNRS UPR 3407, Laboratoire des Sciences des Procédés et des Matériau, Institut Galilée, Université Paris 13, Sorbonne Paris Cité, 99 Avenue Jean-Baptiste Clément, Villetaneuse F-93430 (France); Barbaud, C. [INSERM U1148, Laboratory for Vascular Translational Science (LVTS), Institut Galilée, Université Paris 13, Sorbonne Paris Cité, 99 Avenue Jean-Baptiste Clément, Villetaneuse F-93430 (France); Mora, L., E-mail: Laurence.mora@univ-paris13.fr [INSERM U1148, Laboratory for Vascular Translational Science (LVTS), Institut Galilée, Université Paris 13, Sorbonne Paris Cité, 99 Avenue Jean-Baptiste Clément, Villetaneuse F-93430 (France)

    2016-02-01

    Biodegradable and bioassimilable poly((R,S)-3,3 dimethylmalic acid) (PDMMLA) derivatives were synthesized and characterized in order to develop a new coating for coronary endoprosthesis enabling the reduction of restenosis. The PDMMLA was chemically modified to form different custom groups in its side chain. Three side groups were chosen: the hexyl group for its hydrophobic nature, the carboxylic acid and alcohol groups for their acid and neutral hydrophilic character, respectively. The sessile drop method was applied to characterize the wettability of biodegradable polymer film coatings. Surface energy and components were calculated. The van Oss approach helped reach not only the dispersive and polar acid–base components of surface energy but also acid and basic components. Surface topography was quantified by atomic force microscopy (AFM) and subnanometer average values of roughness (Ra) were obtained for all the analyzed surfaces. Thus, roughness was considered to have a negligible effect on wettability measurements. In contrast, heterogeneous surfaces had to be corrected by the Cassie–Baxter equation for copolymers (10/90, 20/80 and 30/70). The impact of this correction was quantified for all the wettability parameters. Very high relative corrections (%) were found, reaching 100% for energies and 30% for contact angles. - Highlights: • We develop different polymers with various chemical compositions. • Wettability properties were calculated using Cassie corrected contact angles. • Percentage of acid groups in polymers is directly correlated to acid part of SFE. • Cassie corrections are necessary for heterogeneous polymers.

  9. Effect of chemical heterogeneity of biodegradable polymers on surface energy: A static contact angle analysis of polyester model films

    International Nuclear Information System (INIS)

    Belibel, R.; Avramoglou, T.; Garcia, A.; Barbaud, C.; Mora, L.

    2016-01-01

    Biodegradable and bioassimilable poly((R,S)-3,3 dimethylmalic acid) (PDMMLA) derivatives were synthesized and characterized in order to develop a new coating for coronary endoprosthesis enabling the reduction of restenosis. The PDMMLA was chemically modified to form different custom groups in its side chain. Three side groups were chosen: the hexyl group for its hydrophobic nature, the carboxylic acid and alcohol groups for their acid and neutral hydrophilic character, respectively. The sessile drop method was applied to characterize the wettability of biodegradable polymer film coatings. Surface energy and components were calculated. The van Oss approach helped reach not only the dispersive and polar acid–base components of surface energy but also acid and basic components. Surface topography was quantified by atomic force microscopy (AFM) and subnanometer average values of roughness (Ra) were obtained for all the analyzed surfaces. Thus, roughness was considered to have a negligible effect on wettability measurements. In contrast, heterogeneous surfaces had to be corrected by the Cassie–Baxter equation for copolymers (10/90, 20/80 and 30/70). The impact of this correction was quantified for all the wettability parameters. Very high relative corrections (%) were found, reaching 100% for energies and 30% for contact angles. - Highlights: • We develop different polymers with various chemical compositions. • Wettability properties were calculated using Cassie corrected contact angles. • Percentage of acid groups in polymers is directly correlated to acid part of SFE. • Cassie corrections are necessary for heterogeneous polymers.

  10. Biodegradation Potential of Oil-based Drill Cuttings Encapsulated ...

    African Journals Online (AJOL)

    Biodegradation potential of slabs made from oil-based drill cuttings encapsulated with cement in a soil environment has been experimentally investigated. Results of soil analyses show that physico-chemical and biological characteristics of the soil environment as; pH (5.6 – 3.9), temperature (27.7 – 39.5 oC), redox ...

  11. Potential for biodegradation of polycyclic aromatic hydrocarbons by ...

    African Journals Online (AJOL)

    WiTT

    2012-05-08

    May 8, 2012 ... model revealed that N. hatei was the best microorganism in the biodegradation of used motor oil with ... leakage of fuel into the motor oil as well as the ..... Afr. J. Biotechnol. 7(12): 1927-1932. Tanecredi JT (1977). Petroleum hydrocarbons from effluents: detection in marine environment. J. Water Pollut.

  12. Biodegrading effects of some rot fungi on Pinus caribaea wood

    African Journals Online (AJOL)

    STORAGESEVER

    2008-05-16

    May 16, 2008 ... degradation was peculiar with each fungus. Wood decay varied along the tree bole but was not related to height above the ground. The results indicated that biodegradation by rot fungi differs in intensity according to the fungus species and this suggested that preservative impregnation and retention may.

  13. Biodegradation of some agricultural residues by fungi in agitated ...

    African Journals Online (AJOL)

    Digestibility of agricultural residues in animal feeding is deeply dependent on the amounts and types of their fibers. Biological treatment of agricultural residues is a new method for improvement of digestibility. Therefore, the capacity of a few fungi in biodegradation of some agricultural residues was studied. Losses of crude ...

  14. Microbial biodegradable potato starch based low density polyethylene

    African Journals Online (AJOL)

    USER

    2010-06-28

    Jun 28, 2010 ... (Raj, 2003). Also, starch based plastic did not have a negative effect on the environment and also reduced the green house effect (Bastioli, 2001). Synthetic plastic takes a long time to degrade in nature. The use of starch as a biodegradable agent accelarated the time of degradation in the environment.

  15. Biodegradation of Synthetic Polymers by Composting and Fungal Treatment

    Czech Academy of Sciences Publication Activity Database

    Šašek, Václav; Vitásek, J.; Chromcová, D.; Prokopová, I.; Brožek, J.; Náhlík, J.

    2006-01-01

    Roč. 51, č. 5 (2006), s. 425-430 ISSN 0015-5632 R&D Projects: GA ČR GA203/03/0508 Institutional research plan: CEZ:AV0Z50200510 Keywords : biodegradation * composting * synthetic polymers Subject RIV: EE - Microbiology, Virology Impact factor: 0.963, year: 2006

  16. Evaluation of Starch Biodegradable Plastics Derived from Cassava ...

    African Journals Online (AJOL)

    BSN

    Abstract. Starch derived from two cassava cultivars, one with high amylose (TMS 92/0325) and the other with high amylopectin contents (TMS 91/02324), were screened for their ability to produce biodegradable plastics using different compositions of plasticizers and other materials. The rate of degradation of the bioplastics ...

  17. Biodegradation Potential of Oil-based Drill Cuttings Encapsulated ...

    African Journals Online (AJOL)

    Michael Horsfall

    equally divided into 5 plastic containers. Cement encapsulated oil-based drill cuttings were prepared by ... Into each of the plastic containers containing the soil sample, one slab each of the cement encapsulated drill cuttings was ..... Estimating biodegradable municipal solid waste diversion from landfill. Phase 1 Review of ...

  18. Application of a Biodegradable Lubricant in a Diesel Vehicle

    DEFF Research Database (Denmark)

    Schramm, Jesper

    2003-01-01

    , NOx, THC, PM, lubricant-SOF and PAH from one diesel and one gasoline type vehicle using biodegradable lubricants and conventional lubricants. This paper describes the results of the experiments with the diesel type vehicle only. Lubricant consumption and fuel consumption are other important parameters...

  19. Improving oil biodegradability of aliphatic crude oil fraction by ...

    African Journals Online (AJOL)

    Water samples were collected from three oil polluted stations, two replicates for each station, from southern region of Shatt Al-Arab estuary, and southern of Basrah city during the period from September to October 2011. The mineral salts medium was used to isolating oil biodegrading bacteria. Four bacterial species were ...

  20. Biodegradation and abrasive wear of nano restorative materials.

    Science.gov (United States)

    de Paula, A B; Fucio, S B P; Ambrosano, G M B; Alonso, R C B; Sardi, J C O; Puppin-Rontani, R M

    2011-01-01

    The purpose of this study was to evaluate the biomechanical degradation of two nanofilled restorative materials (a resin-modified glass ionomer, Ketac N100 and a composite, Filtek Z350), compared with conventional materials (Vitremer and TPH Spectrum). Twenty specimens obtained from each material were divided into two storage groups (n=10): relative humidity (control) and Streptococcus mutans biofilm (biodegradation). After 7 days of storage, roughness values (Ra) and micrographs by scanning electron microscopy (SEM) were obtained. In a second experimental phase, the specimens previously subjected to biodegradation were fixed to the tooth-brushing device and abraded via toothbrushes, using dentifrice slurry (mechanical degradation). Next, these specimens were washed, dried, and reassessed by roughness and SEM. The data were submitted to repeated measures three-way analysis of variance (ANOVA) and Tukey tests (pabrasion (before/after). After biodegradation (S mutans biofilm storage), Ketac N100 presented the highest Ra values. Concerning bio plus mechanical challenge, TPH Spectrum, Ketac N100, and Vitremer presented the undesirable roughening of their surfaces, while the nano composite Filtek Z350 exhibited the best resistance to cumulative challenges proposed. The degraded aspect after biodegradation and the exposure of fillers after mechanical degradation were visualized in micrographs. This study demonstrated that the nanotechnology incorporated in restorative materials, as in composite resin and resin-modified glass ionomer, was important for the superior resistance to biomechanical degradation.

  1. The use of biodegradable polymers for the stabilization of copper ...

    Indian Academy of Sciences (India)

    Home; Journals; Bulletin of Materials Science; Volume 40; Issue 5. The use of biodegradable polymers for the stabilization of copper nanoparticles synthesized by chemical reduction method. ALI OLAD MAHNAZ ... However, agglomerated copper nanoparticles were obtained bythis chemical reduction method. Hence, the ...

  2. Biodegradation of biodiesel/diesel blends by Candida viswanathii

    African Journals Online (AJOL)

    USER

    2009-06-17

    Jun 17, 2009 ... Without inoculum the biodegradation of diesel oil was higher than biodiesel and blends (47.3, 51.1, 5.7 and 22.1% in ... ferent vegetable oil sources such as soybean, sun-flower, peanut, cotton, palm oil, ... from the waste water of a Brazilian oil refinery (Replan/Petrobras). On Sabouraud's dextrose agar, ...

  3. Improving oil biodegradability of aliphatic crude oil fraction by ...

    African Journals Online (AJOL)

    SAM

    2014-03-12

    Biodegradation of Bonny. Light Crude Oil by Bacteria Isolated from Contaminated Soil. Int. J. Agr. Biol. 13(2):245-250. Uğur A, Ceylan Ö Aslım B (2012). Characterization of Pseudomonas spp. from Seawater of the Southwest ...

  4. Simultaneous quantitative measurement of biodegradability and toxicity of environmental chemicals

    International Nuclear Information System (INIS)

    Kayser, G.; Koch, M.; Ruck, W.

    1994-01-01

    Investigations were made on the biodegradability and bacterial toxicity of chemicals. The intention was to obtain data necessary for estimating and judging the behaviour of these chemicals during aerobic biological waste water treatment. The course of biodegradation and toxicity with time and concentration could be measured, quantified and described. As test procedure, the respirometric dilution method was used. This method is based on a die away test with continuous measuring of the oxygen used for biochemical oxidation processes. The course of the oxygen demand with time and concentration shows the biodegradation and toxicity patterns of the tested chemical. A variety of household and industrial chemicals were investigated. One group of substances were microbiocides, some of which showed toxic effects at concentrations less than 20 mg/l while others were biodegradable even at concentrations of 200 mg/l. Another group of test chemicals were anionic and nonionic detergents. Unexpectedly, some of these substances were toxic at concentrations as little as 50 mg/l. (orig.) [de

  5. Biodegradation and moisture uptake modified starch-filled Linear ...

    African Journals Online (AJOL)

    Sixteen different modified-cassava starch-LLDPE blends containing starch in the range of 10-40% by weight were prepared. Calcium chloride, D-glucose, chloroform and alumina were differently used as modifying agents. The Moisture uptake and biodegradation of each of the composites were investigated. Both of these ...

  6. Application of wheat B-starch in biodegradable plastic materials

    Czech Academy of Sciences Publication Activity Database

    Šárka, E.; Kruliš, Zdeněk; Kotek, Jiří; Růžek, L.; Korbářová, A.; Bubník, Z.; Růžková, M.

    2011-01-01

    Roč. 29, č. 3 (2011), s. 232-242 ISSN 1212-1800 R&D Projects: GA ČR GA525/09/0607 Institutional research plan: CEZ:AV0Z40500505 Keywords : biodegradable plastic * polycaprolactone * B- starch Subject RIV: JI - Composite Materials Impact factor: 0.522, year: 2011 http://www.agriculturejournals.cz/publicFiles/39918.pdf

  7. Biodegradation of biodiesel/diesel blends by Candida viswanathii ...

    African Journals Online (AJOL)

    The biodegradation potential of the inoculum was assessed with the redox indicator 2,6-dichlorophenol indophenol (DCPIP) test and with respirometric experiment in biometer flasks (250 mL) used to measure the microbial CO2 production. In the latter, the inoculum was added to a contaminated soil with the blends ...

  8. A Novel Method for Enhancing Strains' Biodegradation of 4-Chloronitrobenzene.

    Science.gov (United States)

    Li, Tian; Zhang, Tian C; He, Lin

    2017-12-20

    This paper introduces a novel approach to enhance the strains' biodegradation of 4-chloronitrobenzene by utilizing the synergistic effect of the organic reductant mannitol and the substrate beef extraction. Our results demonstrate that 4-chloronitrobenzene could not be an available nitrogen source to support target strains' growth, which induced the limited 4-chloronitrobenzene biodegradation. In addition, the organic reducing agent and substrate had a better synergistic effect than inorganic reducing agent and substrate to enhance the strains' 4-chloronitrobenzene cometabolic biodegradation. Employing the synergistic effect of the optimal mixture (mannitol and beef extraction), the biodegradation rates of 50mgL -1 4-chloronitrobenzene by seven of the ten target strains were enhanced up to 100% from previous removals of no more than 19.1% after 7days. Three of the strains could even completely degrade 100mgL -1 4-chloronitrobenzene while five strains degraded over 91.4%. The method has good potential to enhance bioremediation of various 4-Chloronitrobenzene-contaminated environments as mannitol and beef extraction are non-toxic to the environment. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Biodegradation of penicillin-G wastewater using Phanerochate ...

    African Journals Online (AJOL)

    An attempt was made in the present study to find out the biodegradation of the penicillin-G wastewater for the various operational conditions such as, initial substrate concentrations (13000, 10000, 6000, 4000 and 2000 mg of COD/l), agitation, addition of nutrients (glucose and ammonium chloride) and biomass dosages (2, ...

  10. Biodegradability of unused lubricating brake fluids in fresh and ...

    African Journals Online (AJOL)

    ... Proteus, Escherichia, Micrococcus, Arthrobacter, Enterobacter and Citrobacter was implicated in the biodegradation process in fresh water, while Bacillus, Pseudomonas, Staphylococcus, Enterobacter and Citrobacter was implicated in the marine water source. Similarly, the moulds encountered from the fresh water were, ...

  11. Biodegradation Rates of Aromatic Contaminants in Biofilm Reactors

    DEFF Research Database (Denmark)

    Arcangeli, Jean-Pierre; Arvin, Erik

    1995-01-01

    -reducing conditions, toluene was easily biodegraded. The xylenes and ethylbenzene were degraded cometabolically if toluene was used as a primary carbon source; their removal was influenced by competitive inhibition with toluene. These interaction phenomena are discussed in this paper and a kinetic model taking...

  12. Challenges and opportunities of biodegradable plastics: A mini review.

    Science.gov (United States)

    Rujnić-Sokele, Maja; Pilipović, Ana

    2017-02-01

    The concept of materials coming from nature with environmental advantages of being biodegradable and/or biobased (often referred to as bioplastics) is very attractive to the industry and to the consumers. Bioplastics already play an important role in the fields of packaging, agriculture, gastronomy, consumer electronics and automotive, but still they have a very low share in the total production of plastics (currently about 1% of the about 300 million tonnes of plastic produced annually). Biodegradable plastics are often perceived as the possible solution for the waste problem, but biodegradability is just an additional feature of the material to be exploited at the end of its life in specific terms, in the specific disposal environment and in a specific time, which is often forgotten. They should be used as a favoured choice for the applications that demand a cheap way to dispose of the item after it has fulfilled its job (e.g. for food packaging, agriculture or medical products). The mini-review presents the opportunities and future challenges of biodegradable plastics, regarding processing, properties and waste management options.

  13. Study on the biodegradation of perfluorooctanesulfonate (PFOS and PFOS alternatives

    Directory of Open Access Journals (Sweden)

    Bongin Choi

    2016-01-01

    Full Text Available Objectives In this study, we investigated the biodegradation features of 4 perfluorooctanesulfonate (PFOS alternatives developed at Changwon National University compared to those of PFOS. Methods Biodegradation testing was performed with microorganisms cultured in the good laboratory practice laboratory of the Korea Environment Corporation for 28 days following the Organization for Economic Cooperation and Development guidelines for the testing of chemicals (Test No. 301 C. Results While C8F17SO3Na, PFOS sodium salt was not degraded after 28 days, the 4 alternatives were biodegraded at the rates of 20.9% for C15F9H21S2O8Na2, 8.4% for C17F9H 25S2O8Na2, 22.6% for C23F18H28S2O8Na2, and 23.6% for C25F17H32O13S3Na3. Conclusions C25F17H32S3O13Na3, C23F18H28S2O8Na2, and C15F9H21S2O8Na2 were superior to PFOS in terms of biodegradation rates and surface tension, and thus they were considered highly applicable as PFOS alternatives. Environmental toxicity, human toxicity, and economic feasibility of these compounds should be investigated prior to their commercialization.

  14. Biodegradable Metals for Cardiovascular Stent Application: Interests and New Opportunities

    Directory of Open Access Journals (Sweden)

    Maryam Moravej

    2011-06-01

    Full Text Available During the last decade, biodegradable metallic stents have been developed and investigated as alternatives for the currently-used permanent cardiovascular stents. Degradable metallic materials could potentially replace corrosion-resistant metals currently used for stent application as it has been shown that the role of stenting is temporary and limited to a period of 6–12 months after implantation during which arterial remodeling and healing occur. Although corrosion is generally considered as a failure in metallurgy, the corrodibility of certain metals can be an advantage for their application as degradable implants. The candidate materials for such application should have mechanical properties ideally close to those of 316L stainless steel which is the gold standard material for stent application in order to provide mechanical support to diseased arteries. Non-toxicity of the metal itself and its degradation products is another requirement as the material is absorbed by blood and cells. Based on the mentioned requirements, iron-based and magnesium-based alloys have been the investigated candidates for biodegradable stents. This article reviews the recent developments in the design and evaluation of metallic materials for biodegradable stents. It also introduces the new metallurgical processes which could be applied for the production of metallic biodegradable stents and their effect on the properties of the produced metals.

  15. Biodegradation of low density polyethylene (LDPE) by a new ...

    African Journals Online (AJOL)

    aghomotsegin

    The microbial degradation of LDPE was also analyzed by the change in pH of the culture ... The generation of biodegradable polyethylene requires ...... Use of scanning electron microscope for the examination of actinomycetes. J. Gen. Microbiol. 48:171-177. Yamada-Onodera K, Mukumoto H, Katsuyaya Y, Saiganji A, Tani ...

  16. Biodegradation and adsorption of antibiotics in the activated sludge process.

    Science.gov (United States)

    Li, Bing; Zhang, Tong

    2010-05-01

    The removal of 11 antibiotics of 6 classes, that is, two beta-lactams (ampicillin and cefalexin), two sulfonamides (sulfamethoxazole and sulfadiazine), three fluoroquinolones (norfloxacin, ofloxacin, and ciprofloxacin), one tetracyclines (tetracycline), two macorlides (roxithromycin and anhydro-erythromycin), and one others (trimethoprim), in activated sludge process was investigated using two series of batch reactors treating freshwater and saline sewage respectively. At environmental relevant concentrations tested in this study, biodegradation and adsorption were the major removal routes for the target antibiotics, where volatilization and hydrolysis were neglectable. Among the 11 target antibiotics, cefalexin and the two sulfonamides were predominantly removed by biodegradation in both freshwater and saline sewage systems. Ampicillin, norfloxacin, ciprofloxacin, ofloxacin, tetracycline, roxithromycin, and trimethoprim were mainly removed by adsorption. Divalent cations (Ca(2+) and Mg(2+)) in saline sewage significantly decreased the adsorption of the three fluoroquinolones onto activated sludge. These three fluoroquinolones also exhibited certain biodegradability in the saline activated sludge reactor. Erythromycin-H(2)O was persistent in both saline and freshwater systems under the experimental conditions and could not be removed at all. Kinetics study showed that biodegradation of cefalexin, the two sulfonamides and the three fluoroquinolones followed first-order model well (R(2): 0.921-0.997) with the rate constants ranging from 5.2 x 10(-3) to 3.6 x 10(-1) h(-1).

  17. The development and performance testing of a biodegradable scale inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, Julie; Fidoe, Steve; Jones, Chris

    2006-03-15

    The oil industry is currently facing severe restrictions concerning the discharge of oil field chemicals into the environment. Many commonly used materials in both topside and downhole applications are phased for substitution for use in the North Sea, and more will be identified. The development of biodegradable and low toxicity chemicals, which afford equal or improved efficacy, compared to conventional technology, available at a competitive price, is a current industry challenge. A range of biodegradable materials are increasingly available, however their limited performance can result in a restricted range of applications. This paper discusses the development and commercialization of a readily biodegradable scale inhibitor, ideal for use in topside applications. This material offers a broad spectrum of activity, notably efficiency against barium sulphate, calcium sulphate and calcium carbonate scales, in a range of water chemistries. A range of performance testing, compatibility, stability and OCNS dataset will be presented. Comparisons with commonly used chemicals have been made to identify the superior performance of this phosphate ester. This paper will discuss a scale inhibitor suitable for use in a variety of conditions which offers enhanced performance combined with a favourable biodegradation profile. This material is of great benefit to the industry, particularly in North Sea applications. (author) (tk)

  18. Characterisation and biodegradation of settleable organic matter for ...

    African Journals Online (AJOL)

    Biodegradation of settled COD is studied by evaluating the associated OUR profile obtained in an aerated batch reactor. Hydrolysis was selected, as in current modelling, as the rate-limiting step for O2 consumption. Settled COD was found to incorporate a significant fraction of active biomass that needs to be accounted for ...

  19. Biodegradation of orange G by a novel isolated bacterial strain ...

    African Journals Online (AJOL)

    This research article deals with biodegradation of azo dyes by a newly isolated bacterial strain from soil. Azo dyes are recalcitrant to the conventional modes of treatment due to their complex structure. This article reports decolorization of azo dye by, Gram positive, endospore forming and azo reducing, Bacillus megaterium ...

  20. Influence of chemical structures on biodegradation of azo dyes by ...

    African Journals Online (AJOL)

    Influence of chemical structures on biodegradation of azo dyes by Pseudomonas sp. NA Oranusi, CJ Ogugbue. Abstract. No Abstract. Global Journal of Environmental Sciences Vol. 5(1) 2006: 19-25. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  1. Improvement of landfill leachate biodegradability with ultrasonic process.

    Directory of Open Access Journals (Sweden)

    Amir Hossein Mahvi

    Full Text Available Landfills leachates are known to contain recalcitrant and/or non-biodegradable organic substances and biological processes are not efficient in these cases. A promising alternative to complete oxidation of biorecalcitrant leachate is the use of ultrasonic process as pre-treatment to convert initially biorecalcitrant compounds to more readily biodegradable intermediates. The objectives of this study are to investigate the effect of ultrasonic process on biodegradability improvement. After the optimization by factorial design, the ultrasonic were applied in the treatment of raw leachates using a batch wise mode. For this, different scenarios were tested with regard to power intensities of 70 and 110 W, frequencies of 30, 45 and 60 KHz, reaction times of 30, 60, 90 and 120 minutes and pH of 3, 7 and 10. For determining the effects of catalysts on sonication efficiencies, 5 mg/l of TiO(2 and ZnO have been also used. Results showed that when applied as relatively brief pre-treatment systems, the sonocatalysis processes induce several modifications of the matrix, which results in significant enhancement of its biodegradability. For this reason, the integrated chemical-biological systems proposed here represent a suitable solution for the treatment of landfill leachate samples.

  2. Optimization of BTEX biodegradation in soil using different enhancement methods

    International Nuclear Information System (INIS)

    Kordonska, N.; Biswas, N.; Bewtra, J. K.

    1997-01-01

    Various experiments designed to enhance soil remediation were carried out. Microorganisms, able to utilize benzene, toluene, ethylbenzene and xylene (BTEX) as the sole source of carbon and energy were employed as the inoculum. H-2O 2 was used as a supplemental source of electron acceptor. Nutrients were added to the soil to provide optimum C:N:P. The biodegradation constant was calculated from the BTEX disappearance rate. Results showed that the addition of nutrients improved the rate of biodegradation. When the nutrients were supplemented with additional H 2 O 2 , utilization rate more than doubled. Optimum conditions were created for the biodegradation of all BTEX compounds when an electron acceptor, nutrients and inoculum were added. Under these condition biodegradation increased to almost three times the rate that occurred under natural conditions. Nitrate was successfully used as an alternative electron acceptor by all microorganisms that were able to degrade toluene, ethylbenzene and xylene, however, it was not acceptable as an electron acceptor by degraders of benzene. 9 refs., 3 figs

  3. Toxicity and biodegradability of caffeic acid in anaerobic digesting ...

    African Journals Online (AJOL)

    inhibitory effects of caffeic acid on biogas production as well as its ultimate anaerobic biodegradability; or about the reactive- adsorptive ... and reductive dehydroxylation were the initial activation reactions transforming caffeic acid into typical polyphenol structural ... may lead to products acting differently in terms of toxicity or.

  4. Ecotoxicity and biodegradability of new brominated flame retardants: A review

    Czech Academy of Sciences Publication Activity Database

    Ezechiáš, Martin; Covino, Stefano; Cajthaml, Tomáš

    2014-01-01

    Roč. 110, č. 2 (2014), s. 153-167 ISSN 0147-6513 R&D Projects: GA MŠk(CZ) EE2.3.30.0003; GA TA ČR TE01020218 Institutional support: RVO:61388971 Keywords : Ecotoxicity * brominated flame retardants * biodegradation * review Subject RIV: EE - Microbiology, Virology Impact factor: 2.762, year: 2014

  5. Size-controlled synthesis of biodegradable nanocarriers for targeted ...

    Indian Academy of Sciences (India)

    Abstract. Research for synthesis of size-controlled carriers is currently challenging one. In this research paper, a method for size-controlled synthesis of biodegradable nanocarriers is proposed and described. Salting out method is suitable for both hydrophilic and hydrophobic drugs for the encapsulation on carriers.

  6. Aerobic biodegradation of a mixture of chlorinated organics in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-07-04

    Jul 4, 2008 ... DCM; and 0.232 – 0.588 week-1 for DCA in both water microcosms with higher degradation generally observed in New ... Key words: Bioaugmentation, biodegradation, biostimulation, chlorinated aliphatic hydrocarbons, microcosms. ... culture (OD of 1 at λ600) of the consortia was added separately to.

  7. Enhanced aerobic biodegradation of some toxic hydrocarbon pollutants

    International Nuclear Information System (INIS)

    Elshahawy, M.R.M.

    2007-01-01

    samples were collected from the same location in Suez Gulf during the period from June, 2004 to April 2006 then microbiologically and chemically analyzed . the TPH levels ranged from 55 to 86 ppm and exceeded the known permissible limits referring to a settled situation of chronic hydrocarbon pollution in the studied area. on the other hand the biodegrading bacterial counts cfu clearly reflected the great adaptation of endogenous bacteria to use hydrocarbons as a sole source of carbon . the ratio of biodegrading bacteria to heterotrophic ones ranged between 26 and 50% over the period of collection. the biodegradation potentials of suez gulf consortia were studied at different concentrations of phenanthrene as a sole carbon source. it was found that the degradation kinetics of phenanthrene either due to biotic or abiotic factors is affected with the initial concentration of PAHs. twenty PAHs degraders were isolated from Suez Gulf consortia after different adaptation periods on phenanthrene.ten isolates were selected to be promising due to their ability to tolerate high base oil concentrations, grow at wide range of temperatures and their short incubation period on MSO. the biodegradation kinetics of 200 ppm phenanthrene by the selected isolates was monitored by HPLC

  8. Biodegradation of 2 - methoxyethanol by a new bacterium isolate ...

    African Journals Online (AJOL)

    Microbial biodegradation of 2-methoxyethanol also known as Methyl glycol (MG) under anaerobic conditions has received much attention during the past decade. However, not much is known about the aerobic degradation of 2-methoxyethanol. Samples from various environmental niches were enriched to isolate and ...

  9. A field evaluation of coated urea with biodegradable materials and ...

    African Journals Online (AJOL)

    Urease inhibitor and biodegradable polymer coatings are two most suitable startegies to increase urea fertilizer efficiency. Coating of urea with selected inhibitors can increase the crop production by slowing down the hydrolysis process of urea in the soil. For this purpose, a field experiment was conducted to evaluate the ...

  10. Nonionic surfactant Brij35 effects on toluene biodegradation in a ...

    African Journals Online (AJOL)

    Nonionic surfactant effects on the toluene dissolved in the water phase and biodegradation kinetic behaviors of toluene in a composite bead biofilter were investigated. The toluene dissolved in the water phase was enhanced by the addition of surfactant into aqueous solution and the enhancing effect was more pronounced ...

  11. Biodegradation of Lignocelluloses in Sewage Sludge Composting and Vermicomposting

    Directory of Open Access Journals (Sweden)

    Hosein Alidadi

    2012-08-01

    Full Text Available Please cite this article as: Alidadi H, Najafpour AA, Vafaee A, Parvaresh A, Peiravi R. Biodegradation of lignocelluloses in sewage sludge composting and vermicomposting. Arch Hyg Sci 2012;1(1:1-5.   Aims of the Study: The aim of this study was to determine the amount of lignin degradation and biodegradation of organic matter and change of biomass under compost and vermicomposting of sewage sludge. Materials & Methods: Sawdust was added to sewage sludge at 1:3 weight bases to Carbon to Nitrogen ratio of 25:1 for composting or vermicomposting. Lignin and volatile solids were determined at different periods, of 0, 10, 30, 40 and 60 days of composting or vermicomposting period to determine the biodegradation of lignocellulose to lignin. Results were expressed as mean of two replicates and the comparisons among means were made using the least significant difference test calculated (p <0.05. Results: After 60 days of experiment period, the initial lignin increased from 3.46% to 4.48% for compost and 3.46% to 5.27% for vermicompost. Biodegradation of lignocellulose was very slow in compost and vermicompost processes. Vermicomposting is a much faster process than compost to convert lignocellulose to lignin (p <0.05. Conclusions: The organic matter losses in sewage sludge composting and vermicomposting are due to the degradation of the lignin fractions. By increasing compost age, the amount of volatile solids will decrease.

  12. Biodegradable films based on gelatin extracted from chrome leather scrap.

    Science.gov (United States)

    Dang, Xugang; Shan, Zhihua; Chen, Hui

    2018-02-01

    A biodegradable film based on gelatin extracted from chrome leather scrap was studied in this paper. According to the results of a variety of characterization, the extracted gelatin contains 13 kinds of amino acid; the chrome content is 30mg/kg, mineral and salt content are both at low levels and the nitrogen content is 43.84%. Its molecular weight has been measured at about 6.5kDa ∼26.6kDa, and the average particle distribution appears to be 125nm with a narrow distribution. When the extracted gelatin was modified with the β-cyclodextrin to prepare the biodegradable films, the β-cyclodextrin and gelatin blends can build up perfect compatibility and film-forming properties. Comparing to the gelatin film without β-cyclodextrin, the viscosity, biodegradability, thermal stability and physical properties of the β-cyclodextrin and gelatin blends in the present research were significantly increased, especially when the ratio of β-cyclodextrin to gelatin was 1:2, the biodegradation rates reached 81%, elongation at break 15.74% and the tensile strength 122.34MPa. The blends show perfect swelling properties and overcome the rapid solubility drawback of extracted gelatin. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Biodegradation of premium motor spirit (PMS) by lipase from ...

    African Journals Online (AJOL)

    Biodegradation of premium motor spirit (PMS) by lipase from Bacillus thuringiensis and Lysinibacillus sphaericus. ... The PDF file you selected should load here if your Web browser has a PDF reader plug-in installed (for example, a recent version of Adobe Acrobat Reader). If you would like more information about how to ...

  14. Size-controlled synthesis of biodegradable nanocarriers for targeted ...

    Indian Academy of Sciences (India)

    1, February 2016, pp. 69–77. c Indian Academy of Sciences. Size-controlled synthesis of biodegradable nanocarriers for targeted and controlled cancer drug delivery using salting out cation. MADASAMY HARI BALAKRISHANAN and MARIAPPAN RAJAN∗. Department of Natural Products Chemistry, School of Chemistry, ...

  15. Microbial community dynamics in diesel waste biodegradation using ...

    African Journals Online (AJOL)

    Microbial community dynamics in diesel waste biodegradation using sequencing batch bioreactor operation mode (SBR) ... African Journal of Biotechnology ... Oxygen uptake rate (OUR) indicated increases in microbial activity from cycle one to cycle two (124.9 to 252.9 mgO2/L/h) and decreases in cycles three and four ...

  16. Evaluation of bacterial profile and biodegradation potential of ...

    African Journals Online (AJOL)

    Abattoir wastewater treatments were monitored using physicochemical parameters, bacterial profile and biodegradation potential for 28 days at 7 days intervals. The stages of abattoir wastewater treatment were evaluated through determination of physicochemical parameters such as pH, conductivity, total dissolved solid, ...

  17. Amino Acid Profile of Biodegraded Brewers Spent Grains (BSG ...

    African Journals Online (AJOL)

    The amino acids profiles of biodegraded brewers spent grains (BSG) were determined. The analysis revealed the presence of 17 amino acids including the major amino acids (cysteine, lysine and methionine) required in poultry nutrition. The concentrations of the amino acids however varied with the microbial species used ...

  18. Evaluation of nutrient addition to diesel biodegradation | Singh ...

    African Journals Online (AJOL)

    Increasing public concern towards petroleum pollution demands for new and more environmentally efficient low-cost strategies for cleaning up contaminated sites. Diesel biodegradation by microbial communities was investigated in artificially contaminated soils by supplementing commercial fertilizers under laboratory ...

  19. Biodegradation of shea nut cake by indigenous soil bacteria

    African Journals Online (AJOL)

    User

    hundred and sixty two (162) soil samples were collected at random at 0-20 cm, 20-40 cm and 40-60 cm soil depth from shea nut cake dumping sites in ... Yeast extracts enhanced growth. Pseudomanas strain G9 degraded 71.25% ..... bacterial numbers to hasten biodegradation (Ray,. 1994). The first report on soil bacteria ...

  20. Aerobic biodegradation of butanol and diesel oil blends | Mariano ...

    African Journals Online (AJOL)

    Aerobic biodegradation of butanol and diesel oil blends. Adriano Pinto Mariano, Richard Clayton Tomasella, Clara Di Martino, Eduardo Beraldo Morais, Rubens Maciel Filho, Mirna Helena Regali Seleghim, Jonas Contiero, Sâmia Maria Tauk Tornisielo, Dejanira de Franceschi de Angelis ...

  1. Biodegradation of Polyethylene by Bacillus sp. Indigenous to the ...

    African Journals Online (AJOL)

    Prof. Ogunji

    Available online at www.biotechsocietynigeria.org. Biodegradation of Polyethylene by Bacillus sp. Indigenous to the. Niger Delta Mangrove Swamp. Ibiene, A. A., Stanley, H. O., Immanuel, O. M.. Department of Microbiology, Faculty of Biological Sciences, College of Applied and Natural Sciences,. University of Port Harcourt, ...

  2. Characterization of biodegradable polycaprolactone containing titanium dioxide micro and nanoparticles

    Czech Academy of Sciences Publication Activity Database

    Govorčin Bajsić, E.; Ocelić Bulatović, V.; Šlouf, Miroslav; Šitum, Ana

    2014-01-01

    Roč. 8, č. 7 (2014), s. 536-540 ISSN 2010-376X R&D Projects: GA TA ČR TE01020118 Institutional support: RVO:61389013 Keywords : morphology * polycaprolactone * thermal properties Subject RIV: EA - Cell Biology http://waset.org/Publication/characterization-of-biodegradable-polycaprolactone-containing-titanium-dioxide-micro- and -nanoparticles/9998694

  3. Biodegradation Potentials of Cassava Mill Effluent (CME) by ...

    African Journals Online (AJOL)

    ADOWIE PERE

    This work was aimed at assessing the biodegradation potentials of indigenous microbial isolates from cassava mill effluent ... Bioremediation of cassava mill effluent by these microorganisms was manifested in the reduction of biological oxygen demand ... in the manufacturing industries and degradation or transformation of ...

  4. Biodegradable xylitol-based elastomers: In vivo behavior and biocompatibility

    NARCIS (Netherlands)

    J.P. Bruggeman (Joost); C.J. Bettinger (Christopher); R.S. Langer (Robert)

    2010-01-01

    textabstractBiodegradable elastomers based on polycondensation reactions of xylitol with sebacic acid, referred to as poly(xylitol sebacate) (PXS) elastomers have recently been developed. We describe the in vivo behavior of PXS elastomers. Four PXS elastomers were synthesized, characterized, and

  5. Nanofibers extraction from palm mesocarp fiber for biodegradable polymers incorporation

    International Nuclear Information System (INIS)

    Kuana, Vanessa A.; Rodrigues, Vanessa B.; Takahashi, Marcio C.; Campos, Adriana de; Sena Neto, Alfredo R.; Mattoso, Luiz H.C.; Marconcini, Jose M.

    2015-01-01

    The palm mesocarp fibers are residues produced by the palm oil industries. The objective of this paper is to determine an efficient treatment to extract crystal cellulose nanofibers from the palm mesocarp fibers to be incorporated in biodegradable polymeric composites. The fibers were saponified, bleached and analyzed with thermal gravimetric analysis, X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. (author)

  6. Biodegradability and Microbial Toxicity of Aircraft Fuel System Icing Inhibitors

    National Research Council Canada - National Science Library

    Meshako, Charles

    1996-01-01

    ...%. These concentrations raise concerns as to the disposal and handling of these wastes. The current FSII, DiEGME was evaluated along with two new candidates, dipropylene glycol and glycerol formal DiEGME appeared to be moderately but not completely biodegradable...

  7. Study on optimal biodegradation of terephthalic acid by an isolated ...

    African Journals Online (AJOL)

    The biodegradation of terephthalic acid (TA) by the Pseudomonas sp. was researched in this paper. The optimal nitrogen source was urea with its concentration of 1400 mg/l. The optimal conditions for TA degradation were optimized by orthogonal test. The test result showed the pH 7.0, temperature of 30°C and shaking ...

  8. Evaluation of Starch Biodegradable Plastics Derived from Cassava ...

    African Journals Online (AJOL)

    Starch derived from two cassava cultivars, one with high amylose (TMS 92/0325) and the other with high amylopectin contents (TMS 91/02324), were screened for their ability to produce biodegradable plastics using different compositions of plasticizers and other materials. The rate of degradation of the bioplastics produced ...

  9. Rate of biodegradation of crude oil by microorganisms isolated from ...

    African Journals Online (AJOL)

    The rate of biodegradation of crude oil by micro-organisms isolated from crude oil sludge environment in Eket, Akwa Ibom State of Nigeria was studied. Mineral salt medium supplemented with crude oil was used and three most abundant species isolated from a crude oil sludged soil - Micrococcus varians, Bacillus subtilis ...

  10. The use of ecocores to evaluate biodegradation in marine sediments

    DEFF Research Database (Denmark)

    Jensen, Kurt; Albrechtsen, Hans-Jørgen; Nielsen, Jef

    1988-01-01

    A laboratory sediment microcosm called the ecocore is described. It has been used to test the biodegradability of substances which predominantly enter the sediment. A new method for introducing hydrophobic test substances such as hydrocarbons to the test system is also described. In a series of t...

  11. Bio-Based Polymers with Potential for Biodegradability

    Directory of Open Access Journals (Sweden)

    Thomas F. Garrison

    2016-07-01

    Full Text Available A variety of renewable starting materials, such as sugars and polysaccharides, vegetable oils, lignin, pine resin derivatives, and proteins, have so far been investigated for the preparation of bio-based polymers. Among the various sources of bio-based feedstock, vegetable oils are one of the most widely used starting materials in the polymer industry due to their easy availability, low toxicity, and relative low cost. Another bio-based plastic of great interest is poly(lactic acid (PLA, widely used in multiple commercial applications nowadays. There is an intrinsic expectation that bio-based polymers are also biodegradable, but in reality there is no guarantee that polymers prepared from biorenewable feedstock exhibit significant or relevant biodegradability. Biodegradability studies are therefore crucial in order to assess the long-term environmental impact of such materials. This review presents a brief overview of the different classes of bio-based polymers, with a strong focus on vegetable oil-derived resins and PLA. An entire section is dedicated to a discussion of the literature addressing the biodegradability of bio-based polymers.

  12. Size-controlled synthesis of biodegradable nanocarriers for targeted ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Research for synthesis of size-controlled carriers is currently challenging one. In this research paper, a method for size-controlled synthesis of biodegradable nanocarriers is proposed and described. Salting out method is suitable for both hydrophilic and hydrophobic drugs for the encapsulation on carriers.

  13. Obtención de microesferas biodegradables de ácido poli L-láctico cargadas con doxorubicina Obtention of biodegradable microspheres of poly l-lactic acid loaded with doxorubicin

    Directory of Open Access Journals (Sweden)

    Dianelis Fernández Mena

    2005-04-01

    Full Text Available Se ha demostrado que las microesferas biodegradables de ácido poli L-láctico como portadores de fármacos proporcionan una liberación controlada y mantenida del principio activo, disminuyendo los efectos colaterales que estos pueden provocar. Por este motivo, se propuso evaluar la influencia de parámetros como el rendimiento, la eficiencia de encapsulación y el diámetro medio de las partículas, en el proceso de preparación de microesferas cargadas con doxorubicina, por el método de emulsión múltiple y evaporación del solvente. Se comprobó que la concentración de alcohol polivinílico y cloruro de sodio, así como la baja temperatura en la fase acuosa externa contribuyen a lograr mejores resultados en las características físico-químicas de las microesferas obtenidas.It has been proved that the biodegradable microspheres of poly l-lactic acid as drug carriers provide a controlled and maintained release of the active principle, reducing the side effects they may cause. For this reason, it was proposed to evaluate the influence of parameters such as performance, encapsulation efficiency and mean diameter of the particles, in the process of preparation of microspheres loaded with doxorubicin by the method of multiple emulsion and evaporation of the solvent. It was proved that the concentration of polyvinyl alcohol and sodium chloride, as well as the low temperature in the external aqueous phase, contribute to attain better results in the physical and chemical characteristics of the obtained microspheres

  14. The effects of biodegradation and photodegradation on DOM optical properties

    Science.gov (United States)

    Hansen, A.; Moll, L.; Kraus, T. E.

    2012-12-01

    In aquatic environments, dissolved organic matter (DOM) plays a central role in ecosystem biogeochemistry and is important because it affects light penetration, food web dynamics, and pollutant transport. While knowing DOM concentration is important, it is also critical to characterize DOM composition because its chemical make-up determines how it reacts in the environment. Furthermore, the ability to determine the origin of DOM can help inform watershed management and predict future trends. The main factors affecting DOM composition include (1) original source material, (2) biodegradation, and (3) photodegradation. Many studies use optical properties (absorbance and fluorescence) to infer DOM composition and source, however there are few controlled laboratory studies using endmember sources. Here DOM optical properties of eight endmember sources-including soil, plant and algal leachates-from San Francisco Bay Delta wetlands were investigated following biological and photochemical degradation during a three month incubation period. The effects of photoexposure were examined at various points along the biodegradation curve to simulate photodegradation occurring as microorganisms consumed and transformed the bioavailable DOM. Samples were analyzed for dissolved organic carbon (DOC) concentration, absorbance, and fluorescence. While our results showed little change in DOC concentration in the soil leachate over the 3 month study period, DOC concentrations in plant and algal leachates decrease by over 70% within the first three days of biodegradation. As expected, biodegradation led to an increase in fluorescence index (FI), humic index (HIX), and specific absorbance (SUVA) values. Carbon-normalized fluorescence values increased for humic-like components associated with Peaks C and A, but decreased for more labile material, which is associated with Peak T. While the initial FI for plant and algal leachates was similar to soil, the FI for both of these sources increased

  15. Research regarding biodegradable properties of food polymeric products under microorganism activity

    Science.gov (United States)

    Opran, Constantin; Lazar, Veronica; Fierascu, Radu Claudiu; Ditu, Lia Mara

    2018-02-01

    Aim of this research is the structural analysis by comparison of the biodegradable properties of two polymeric products made by non-biodegradable polymeric material (polypropylene TIPPLEN H949 A) and biodegradable polymeric material (ECOVIO IS 1335), under microorganism activity in order to give the best solution for the manufacture of food packaging biodegradable products. It presents the results of experimental determinations on comparative analysis of tensile strength for the two types of polymers. The sample weight variations after fungal biodegradation activity revealed that, after 3 months, there are no significant changes in polymeric substratum for non-biodegradable polymeric. The microscopically analysis showed that the fungal filaments did not strongly adhered on the non-biodegradable polymeric material, instead, both filamentous fungi strains adhered and covered the surface of the biodegradable sample with germinated filamentous conidia. The spectral analysis of polymer composition revealed that non-biodegradable polymer polypropylene spectra are identical for control and for samples that were exposed to fungal activity, suggesting that this type of sample was not degraded by the fungi strains. Instead, for biodegradable polymer sample, it was observed significant structural changes across multiple absorption bands, suggesting enzyme activity manifested mainly by Aspergillus niger strain. Structural analysis of interdisciplinary research results, lead, to achieving optimal injection molded technology emphasizing technological parameters, in order to obtain food packaging biodegradable products.

  16. FastStats: Alcohol Use

    Science.gov (United States)

    ... this? Submit What's this? Submit Button NCHS Home Alcohol Use Recommend on Facebook Tweet Share Compartir Data ... alcoholic liver disease deaths: 21,028 Number of alcohol-induced deaths, excluding accidents and homicides: 33,171 ...

  17. Alcohol and older drivers' crashes.

    Science.gov (United States)

    2014-09-01

    Researchers have examined the effects of alcohol consumption : on older adults functioning, and some have : addressed alcohols effects on older drivers crash risk. : Generally, the findings have shown that alcohol is less : likely to be a fa...

  18. Preparation and properties of polyvinyl alcohol (PVA) and hydroxylapatite (HA) hydrogels for cartilage tissue engineering.

    Science.gov (United States)

    Yuan, F; Ma, M; Lu, L; Pan, Z; Zhou, W; Cai, J; Luo, S; Zeng, W; Yin, F

    2017-05-20

    A novel bioactive hydrogel for cartilage tissue based on polyvinyl alcohol (PVA) and hydroxylapatite (HA) were prepared, the effects of its component contents on the mechanical properties and microstructure of the hydrogel were investigated. The important properties of the scaffold composites, such as density, porosity, compressive modulus and microstructure were studied and analyzed through various measurements and methods. The biodegradability of hydrogel was evaluated by soaking the samples into artificial degradation solution at body temperature (36 - 37 oC) in vitro. Experimental results showed that the PVA/HA hydrogels had a density of 0.572 - 0.683 g/cm3, a porosity of 63.25 - 96.14% and a compressive modulus of 5.62 - 8.24 MP. The HA compound in the hydrogels enhanced the biodegradation significantly and linearly increased the rate of biodegradation by 2.3 - 8.5 %. The compressive modulus of PVA/HA exhibited a linear reduce to 0.86 - 1.53 MP with the time of degradation. The scaffold composites PVA/HA possess a high porosity, decent compressive modulus and good biodegradability. After further optimizing the structure and properties, this composite might be considered as novel hydrogel biomaterials to be applied in the field of cartilage tissue engineering.

  19. Cementation of biodegraded radioactive oils and organic waste

    International Nuclear Information System (INIS)

    Gorbunova, O.; Safonov, A.; Tregubova, V.; German, K.

    2015-01-01

    The possibility of the microbiological pre-treatment of the oil-containing organic liquid radioactive waste (LRW) before solidification in the cement matrix has been studied. It is experimentally proved that the oil containing cement compounds during long-term storage are subject to microbiological degradation due to the reaction of biogenic organic acids with the minerals of the cement matrix. We recommend to biodegrade the LRW components before their solidification, which reduces the volume of LRW and prevent the destruction of the inorganic cement matrix during the long term storage. The biodegradation of the oil containing LRW is possible by using the radioresistant microflora which oxidize the organic components of the oil to carbon dioxide and water. Simultaneously there is the bio-sorption of the radionuclides by bacteria and emulsification of oil in cement slurry due to biogenic surface-active substances of glycolipid nature. It was experimentally established that after 7 days of biodegradation of oil-containing liquid radioactive waste the volume of LRW is reduced by the factor from 2 to 10 due to the biodegradation of the organic phase to the non-radioactive gases (CH 4 , H 2 O, CO 2 , N 2 ), which are excluded from the volume of the liquid radioactive waste. At the same time, the microorganisms are able to extract from the LRW up to 80-90% of alpha-radionuclides, up to 50% of 90 Sr, up to 20% of 137 Cs due to sorption processes at the cellular structures. The radioactive biomass is subject to dehydration and solidification in the matrix. The report presents the following experimental data: type of bacterial flora, the parameters of biodegradation, the cementing parameters, the properties of the final cement compound with oil-containing liquid radioactive waste

  20. Assessing Biodegradation Susceptibilities of Selected Petroleum Hydrocarbons at Contaminated Soils

    Directory of Open Access Journals (Sweden)

    Markus Heryanto Langsa

    2010-01-01

    Full Text Available The susceptibility to biodegradation of selected saturated hydrocarbons (SHCs, polycyclic aromatichydrocarbons (PAHs and asphaltenes in a Barrow crude oil and extracts isolated from soils contaminated with theBarrow crude oil at day 0 and 39 was determined. Soil samples were contaminated with a Barrow crude oil across thesurface (5% w/w as part of a mesocosm experiment in order to mimic similar conditions in the environment. Theextent of biodegradation of the Barrow oil extracted from the contaminated soils at day 0 and day 39 was assessed byGC-MS analyses of SHCs and PAHs fractions. Changes in the relative abundances of n-alkanes (loss of low-molecularweighthydrocarbons and pristane relative to phytane (Pr/Ph and their diastereoisomers were determined. Changesin the diastereoisomer ratios of Pr and Ph relate to the decrease in abundance of the phytol-derived 6(R,10(Sisoprenoids with increasing biodegradation. The percentage change in abundances of each of selectedalkylnaphathalenes with time (day 0 to 39 was determined, enabling an order of susceptibility of their isomers tobiodegradation. It was established that the 2-methylnaphthalene isomers (2-MN is more susceptible to microbialattack than 1-MN isomer indicated by decreasing in percent abundance from day 0 to 39 for the 2-MN isomer. TheGC-MS analyses of the original Barrow oil indicated the oil had not undergone biodegradation. When this oil wasused in the soil mesocosm experiments the oil was shown to biodegrade to about a level 2 -3 based on the biodegradationsusceptibility of the various SHCs and PAHs described above