WorldWideScience

Sample records for dioxide fixation pathways

  1. CARBON DIOXIDE FIXATION.

    Energy Technology Data Exchange (ETDEWEB)

    FUJITA,E.

    2000-01-12

    Solar carbon dioxide fixation offers the possibility of a renewable source of chemicals and fuels in the future. Its realization rests on future advances in the efficiency of solar energy collection and development of suitable catalysts for CO{sub 2} conversion. Recent achievements in the efficiency of solar energy conversion and in catalysis suggest that this approach holds a great deal of promise for contributing to future needs for fuels and chemicals.

  2. The design and realization of synthetic pathways for the fixation of carbon dioxide in vitro

    OpenAIRE

    Schwander, Thomas; Erb, Tobias (Dr.)

    2018-01-01

    The fixation of inorganic carbon and the conversion to organic molecules is a prerequisite for life and the foundation of the carbon cycle on Earth. Since the industrial revolution, this carbon cycle has become inbalanced and consequently the atmospheric carbon dioxide (CO2) concentration is increasing and is a major cause of global warming. On the contrary, atmospheric CO2 can also be considered as an important carbon feedstock o...

  3. Current views on the regulation of autotrophic carbon dioxide fixation via the Calvin cycle in bacteria

    NARCIS (Netherlands)

    Dijkhuizen, L.; Harder, W.

    1984-01-01

    The Calvin cycle of carbon dioxide fixation constitutes a biosynthetic pathway for the generation of (multi-carbon) intermediates of central metabolism from the one-carbon compound carbon dioxide. The product of this cycle can be used as a precursor for the synthesis of all components of cell

  4. Carbon dioxide fixation in isolated Kalanchoe chloroplasts

    Energy Technology Data Exchange (ETDEWEB)

    Levi, C.; Gibbs, M.

    1975-07-01

    Chloroplasts isolated from Kalanchoe diagremontiana leaves were capable of photosynthesizing at a rate of 5.4 ..mu..moles of CO/sub 2/ per milligram of chlorophyll per hour. The dark rate of fixation was about 1 percent of the light rate. A high photosynthetic rate was associated with low starch content of the leaves. Ribose 5-phosphate, fructose 1, 6-diphosphate, and dithiothreitol stimulated fixation, whereas phosphoenolpyruvate and azide were inhibitors. The products of CO/sub 2/ fixation were primarily those of the photosynthetic carbon reduction cycle. (auth)

  5. POSSIBILITIES OF CARBON DIOXIDE FIXATION BY MICROALGAE IN REFINERY

    OpenAIRE

    Šingliar, Michal; Mikulec, Jozef; Kušnir, Patrik; Polakovičova, Gabriela

    2013-01-01

    Capture and sequestration of carbon dioxide is one of the most critical challenges today for businesses and governments worldwide. Thousands of emitting power plants and industries worldwide face this costly challenge – reduce the CO2 emissions or pay penalties. One possibility for carbon dioxide sequestration is its fixation in microalgae. Microalgae can sequester CO2 from flue gases emitted from fossil fuel-fired refinery plants and units, thereby reducing emissions of a major greenhouse ga...

  6. Dependence of carbon dioxide concentration on microalgal carbon dioxide fixation

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Yeoung Sang; Park, Song Moon [Department of Chemical Engineering, School of Environmental Engineering, Pohang University of Science and Technology, Pohang (Korea); Bolesky, Bohumil [Department of Chemical Engineering, McGill University (Canada)

    1999-10-01

    Batch cultivation of chlorella vulgaris was carried out under various CO{sub 2} concentrations in order to understand and describe mathematically the CO{sub 2} inhibition of microalgal CO{sub 2} fixation. The volumetric CO{sub 2} transfer coefficient from mixture gas to culture medium was estimated from the volumetric O{sub 2} transfer coefficient obtained experimentally. Using this transfer coefficient and aquatic equilibrium relationship between dissolved inorganic carbons, the behavior of dissolved CO{sub 2} was calculated during microalgal culture. When air containing 0.035%(v/v) CO{sub 2} was supplied into microalgal culture, the fixation rate was limited by CO{sub 2} transfer rate. However, the limitation was disappeared by supplying mixture gas containing above 2%(v/v) CO{sub 2} and the dissolved CO{sub 2} concentration was maintained at the saturated value. In the range of CO{sub 2} partial pressure in the flue gases from thermal power sations and steel-making plants, the microalgal CO{sub 2} fixation rate was inhibited. The CO{sub 2} fixation rate was successfully formulated by a new empirical equation as a function of dissolved CO{sub 2} concentration, which could be useful for modeling and simulating the performance of photobioreaction with enriched CO{sub 2}. Also, it was found that the CO{sub 2} inhibition of microalgal CO{sub 2} fixation was reversible and that microalgal CO{sub 2} fixation process could be stable against a shock of unusually high CO{sub 2} concentration. 29 refs., 8 figs.

  7. Carbon dioxide fixation by microalgae cultivated in open bioreactors

    Energy Technology Data Exchange (ETDEWEB)

    Centeno da Rosa, Ana Priscila; Fernandes Carvalho, Lisiane; Goldbeck, Luzia [Laboratory of Biochemical Engineering, College of Chemistry and Food, Federal University of Rio Grande (FURG), P.O. Box 474, Rio Grande, RS 96201-900 (Brazil); Vieira Costa, Jorge Alberto, E-mail: dqmjorge@furg.br [Laboratory of Biochemical Engineering, College of Chemistry and Food, Federal University of Rio Grande (FURG), P.O. Box 474, Rio Grande, RS 96201-900 (Brazil)

    2011-08-15

    Highlights: {yields} We studied the growth and CO{sub 2} fixation by Spirulina LEB18 and Chlorella kessleri. {yields} The maximum dailyfixation was obtained for Spirulina with an injection of 6% of CO{sub 2}. {yields} The microalgae presented growth during the 20 d of culture with up to 18% of CO{sub 2}. {yields} The use of CO{sub 2} from industrial generation decreases the cost of producing biomass. - Abstract: The biofixation of carbon dioxide (CO{sub 2}) by microalgae has been proven to be an efficient and economical method, mainly due to the photosynthetic ability of these microorganisms to use this gas as a source of nutrients for their development. The aim of this work was to study the growth of Spirulina LEB18 and Chlorella kessleri microalgae, exposed to controlled and non-controlled conditions, with the injection of different concentrations of CO{sub 2}. The cultures was carried out in 6 L open raceway ponds, under controlled conditions at 30 {sup o}C and 39 {mu}E m{sup -2} s{sup -1} and under non-controlled conditions, protected by a tunnel of transparent film. The experiments were subjected to CO{sub 2} injections at concentrations of 0.038, 6, 12 and 18% (v/v). The highest concentration of biomass (4.95 g L{sup -1}) and maximum daily fixation (0.21 g g{sup -1} d{sup -1}) were obtained for Spirulina LEB18 in culture that was prepared in non-controlled conditions with an injection of 6% (v/v) of CO{sub 2}. C. kessleri had maximum (p < 0.0008) specific growth rate (0.84 d{sup -1}) when grown with 18% (v/v) of CO{sub 2} in non-controlled conditions of cultivation.

  8. Carbon dioxide fixation by microalgae cultivated in open bioreactors

    International Nuclear Information System (INIS)

    Centeno da Rosa, Ana Priscila; Fernandes Carvalho, Lisiane; Goldbeck, Luzia; Vieira Costa, Jorge Alberto

    2011-01-01

    Highlights: → We studied the growth and CO 2 fixation by Spirulina LEB18 and Chlorella kessleri. → The maximum dailyfixation was obtained for Spirulina with an injection of 6% of CO 2 . → The microalgae presented growth during the 20 d of culture with up to 18% of CO 2 . → The use of CO 2 from industrial generation decreases the cost of producing biomass. - Abstract: The biofixation of carbon dioxide (CO 2 ) by microalgae has been proven to be an efficient and economical method, mainly due to the photosynthetic ability of these microorganisms to use this gas as a source of nutrients for their development. The aim of this work was to study the growth of Spirulina LEB18 and Chlorella kessleri microalgae, exposed to controlled and non-controlled conditions, with the injection of different concentrations of CO 2 . The cultures was carried out in 6 L open raceway ponds, under controlled conditions at 30 o C and 39 μE m -2 s -1 and under non-controlled conditions, protected by a tunnel of transparent film. The experiments were subjected to CO 2 injections at concentrations of 0.038, 6, 12 and 18% (v/v). The highest concentration of biomass (4.95 g L -1 ) and maximum daily fixation (0.21 g g -1 d -1 ) were obtained for Spirulina LEB18 in culture that was prepared in non-controlled conditions with an injection of 6% (v/v) of CO 2 . C. kessleri had maximum (p -1 ) when grown with 18% (v/v) of CO 2 in non-controlled conditions of cultivation.

  9. Effects of elevated carbon dioxide concentration on growth and N2 fixation of young Robinia pseudoacacia

    International Nuclear Information System (INIS)

    Feng, Z; Flessa, H.; Dyckmans, J.

    2004-01-01

    The effects of elevated carbon dioxide concentration on carbon and nitrogen uptake and nitrogen source partitioning were determined in one year-old locust trees using a dual 13 C and 15 N continuous labelling experiment. Elevated carbon dioxide increased the fraction of new carbon in total carbon, but it did not alter carbon partitioning among plant compartments. Elevated carbon dioxide also increased the fraction of new nitrogen in total nitrogen. This was coupled with a shift in nitrogen source partitioning toward nitrogen fixation. Soil nitrogen uptake was not affected, but nitrogen fixation was markedly increased by elevated carbon dioxide treatment. The increased nitrogen fixation tended to decrease the C/N ratio in the presence of elevated carbon dioxide. Total dry mass of root nodules doubled in response to elevated carbon dioxide, however, this effect was not considered significant because of the great variability in root nodule formation. Overall, it was concluded that the growth of locust trees in an elevated carbon dioxide environment will not primarily be limited by nitrogen availability, giving the R. pseudoacacia species a competitive advantage over non-nitrogen-fixing tree species. It was also suggested that the increase in nitrogen fixation observed in response to elevated carbon dioxide treatment may play a key role in the growth response of forest ecosystems to elevated carbon dioxide by improving nitrogen availability for non-nitrogen-fixing trees. 51 refs., 1 tab., 4 figs

  10. Carbon Dioxide Fixation in Isolated Kalanchoe Chloroplasts 1

    Science.gov (United States)

    Levi, Carolyn; Gibbs, Martin

    1975-01-01

    Chloroplasts isolated from Kalanchoe diagremontiana leaves were capable of photosynthesizing at a rate of 5.4 μmoles of CO2 per milligram of chlorophyll per hour. The dark rate of fixation was about 1% of the light rate. A high photosynthetic rate was associated with low starch content of the leaves. Ribose 5-phosphate, fructose 1,6-diphosphate, and dithiothreitol stimulated fixation, whereas phosphoenolpyruvate and azide were inhibitors. The products of CO2 fixation were primarily those of the photosynthetic carbon reduction cycle. PMID:16659249

  11. Water Conservation in Kalanchoe blossfeldiana in Relation to Carbon Dioxide Dark Fixation.

    Science.gov (United States)

    Zabka, G G; Chaturvedi, S N

    1975-03-01

    The succulent Kalanchoe blossfeldiana v. Poel. var Tom Thumb was treated on long and short photoperiods for 6 weeks during which short day plants developed thicker leaves, flowered prolifically, and exhibited extensive net dark fixation of carbon dioxide. In contrast, long day plants remained vegetative and did not develop thicker leaves or exhibit net carbon dioxide dark fixation. When examined after the photoperiodic state described, long day plants showed approximately three times more water loss over a 10-day period than short day plants. Water loss is similar during light and dark periods for short day plants but long day plants exhibited two times more water loss during the day than at night. The latter plants also lost three and one-half times more water during the light period than short day plants. The water conservation by short day plants is correlated with conditions of high carbon dioxide dark fixation and effects of its related Crassulacean acid metabolism on stomatal behavior.

  12. Fixation of carbon dioxide into dimethyl carbonate over ...

    Science.gov (United States)

    A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon dioxide. The developed catalyst activates carbon dioxide and delivers over 16% yield of DMC without the use of any dehydrating agent or requirement for azeotropic distillation. Prepared for submission to Nature Scientific reports.

  13. Fixation of carbon dioxide by coral reef. Sangosho ni yoru CO2 no kotei

    Energy Technology Data Exchange (ETDEWEB)

    Yamamuro, M [Geological Survey of Japan, Tsukuba, Ibaraki (Japan)

    1993-08-01

    The methods for fixation of carbon dioxide in the atmosphere in order to control the greenhouse effect, are groped. Carbon is fixed through two ways such as the production of organic compounds by photosynthesis and formation of calcium carbonate by calcification. Among them, the photosynthesis fixes carbon dioxide in the air, and calcification, on thinking of only chemical equilibrium in the sea water, is a process to exhaust carbon dioxide from ocean to the atmosphere. It is, therefore, uneven in opinions of researchers if the coral reef is an absorbing source or an exhausting one of carbon dioxide. A conventional discussion on this theme, did not carry out based on the actual search or measurement, but preceded on modelling. In order, therefore, to introduce a scientific decision on a play of the coral reef for the global carbon circulation, it seems to take more time. In this paper, an opinion that the coral reef is an absorbing source of carbon dioxide in the air according to some measuring results of carbon dioxide fixation velocity and organic compounds volume in sediments in the coral reefs, are described. 11 refs., 4 figs.

  14. The impact of environmental factors on carbon dioxide fixation by microalgae.

    Science.gov (United States)

    Morales, Marcia; Sánchez, León; Revah, Sergio

    2018-02-01

    Microalgae are among the most productive biological systems for converting sunlight into chemical energy, which is used to capture and transform inorganic carbon into biomass. The efficiency of carbon dioxide capture depends on the cultivation system configuration (photobioreactors or open systems) and can vary according to the state of the algal physiology, the chemical composition of the nutrient medium, and environmental factors such as irradiance, temperature and pH. This mini-review is focused on some of the most important environmental factors determining photosynthetic activity, carbon dioxide biofixation, cell growth rate and biomass productivity by microalgae. These include carbon dioxide and O2 concentrations, light intensity, cultivation temperature and nutrients. Finally, a review of the operation of microalgal cultivation systems outdoors is presented as an example of the impact of environmental conditions on biomass productivity and carbon dioxide fixation. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Biological fixation of carbon dioxide. Seibutsu ni yoru nisanka tanso no kotei

    Energy Technology Data Exchange (ETDEWEB)

    Someya, J [Fermentaion Research Institute, Tsukuba (Japan)

    1991-10-20

    Bulks of photosynthetic product to reduce the carbon dioxide by the light energy are forests, represented by the tropical rain forests, on the land, and marine algae and coral reefs in the ocean. For the purpose of effectively utilizing the fixation power of carbon dioxide through the photosynthesis by higher plants and algae, it is necessary to make many further researches, starting with a conditional selection of species, excellent in both absorption and fixation of carbon dioxide. The Japan Technology Transfer Association has recently issued a design to build a large scale closed type farm in the vicinity of factory, exhausting the carbon dioxide, and supply it to structure a system of producing vegetable and other food. What largely contributes to the calcification in the ocean is the coral reefs, where coral is symbiotic with brown algae., called dinoflagellatae. Those algae are judged to accelerate the formation of calcium carbonate by the photosynthesis. To estimate the absorption power of oceanic carbon dioxide, it is important to quantitatively know the calcification by the coral. 4 figs., 1 tab.

  16. Measurement of carbon fixation and allocation using 11C-labeled carbon dioxide

    International Nuclear Information System (INIS)

    Strain, B.R.; Goeschl, J.D.; Jaeger, C.H.; Fares, Y.; Magnuson, C.E.; Nelson, C.E.

    1983-01-01

    This paper describes the use of continuously produced and applied 11 C in measurements of carbon dioxide assimilation and C movement in plant research. This technique differs from the pulsing type 11 C research underway in other laboratories by being continuous and on-line with computer analysis making steady-state measurements of carbon fixation and movement possible. The studies to be described here make clear the advantages of using continuously produced and applied short half-lived isotopes

  17. Two Iron Complexes as Homogeneous and Heterogeneous Catalysts for the Chemical Fixation of Carbon Dioxide.

    Science.gov (United States)

    Karan, Chandan Kumar; Bhattacharjee, Manish

    2018-04-16

    Two new bimetallic iron-alkali metal complexes of amino acid (serine)-based reduced Schiff base ligand were synthesized and structurally characterized. Their efficacy as catalysts for the chemical fixation of carbon dioxide was explored. The heterogeneous version of the catalytic reaction was developed by the immobilization of these homogeneous bimetallic iron-alkali metal complexes in an anion-exchange resin. The resin-bound complexes can be used as recyclable catalysts up to six cycles.

  18. Water Conservation in Kalanchoe blossfeldiana in Relation to Carbon Dioxide Dark Fixation

    Science.gov (United States)

    Zabka, George G.; Chaturvedi, S. N.

    1975-01-01

    The succulent Kalanchoe blossfeldiana v. Poel. var Tom Thumb was treated on long and short photoperiods for 6 weeks during which short day plants developed thicker leaves, flowered prolifically, and exhibited extensive net dark fixation of carbon dioxide. In contrast, long day plants remained vegetative and did not develop thicker leaves or exhibit net carbon dioxide dark fixation. When examined after the photoperiodic state described, long day plants showed approximately three times more water loss over a 10-day period than short day plants. Water loss is similar during light and dark periods for short day plants but long day plants exhibited two times more water loss during the day than at night. The latter plants also lost three and one-half times more water during the light period than short day plants. The water conservation by short day plants is correlated with conditions of high carbon dioxide dark fixation and effects of its related Crassulacean acid metabolism on stomatal behavior. PMID:16659116

  19. Clinical and histomorphometrical study on titanium dioxide-coated external fixation pins

    Directory of Open Access Journals (Sweden)

    Koseki H

    2013-02-01

    Full Text Available Hironobu Koseki,1 Tomohiko Asahara,1 Takayuki Shida,1 Itaru Yoda,1 Hidehiko Horiuchi,1 Koumei Baba,2 Makoto Osaki11Department of Orthopedic Surgery, Graduate School of Medicine, Nagasaki University, 2Industrial Technology Center of Nagasaki, Nagasaki, JapanBackground: Pin site infection is the most common and significant complication of external fixation. In this work, the efficacy of pins coated with titanium dioxide (TiO2 for inhibition of infection was compared with that of stainless steel control pins in an in vivo study.Methods: Pins contaminated with an identifiable Staphylococcus aureus strain were inserted into femoral bone in a rat model and exposed to ultraviolet A light for 30 minutes. On day 14, the animals were sacrificed and the bone and soft tissue around the pin were retrieved. The clinical findings and histological findings were evaluated in 60 samples.Results: Clinical signs of infection were present in 76.7% of untreated pins, but in only 36.7% of TiO2-coated pins. The histological bone infection score and planimetric rate of occupation for bacterial colonies and neutrophils in the TiO2-coated pin group were lower than those in the control group. The bone-implant contact ratio of the TiO2-coated pin group was significantly higher (71.4% than in the control pin group (58.2%. The TiO2 was successful in decreasing infection both clinically and histomorphometrically.Conclusion: The photocatalytic bactericidal effect of TiO2 is thought to be useful for inhibiting pin site infection after external fixation.Keywords: titanium dioxide, external fixation, bactericidal activity, Staphylococcus aureus

  20. A Stable Metal-Organic Framework Featuring a Local Buffer Environment for Carbon Dioxide Fixation.

    Science.gov (United States)

    He, Hongming; Sun, Qi; Gao, Wenyang; Perman, Jason A; Sun, Fuxing; Zhu, Guangshan; Aguila, Briana; Forrest, Katherine; Space, Brian; Ma, Shengqian

    2018-04-16

    A majority of metal-organic frameworks (MOFs) fail to preserve their physical and chemical properties after exposure to acidic, neutral, or alkaline aqueous solutions, therefore limiting their practical applications in many areas. The strategy demonstrated herein is the design and synthesis of an organic ligand that behaves as a buffer to drastically boost the aqueous stability of a porous MOF (JUC-1000), which maintains its structural integrity at low and high pH values. The local buffer environment resulting from the weak acid-base pairs of the custom-designed organic ligand also greatly facilitates the performance of JUC-1000 in the chemical fixation of carbon dioxide under ambient conditions, outperforming a series of benchmark catalysts. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Clinical and histomorphometrical study on titanium dioxide-coated external fixation pins.

    Science.gov (United States)

    Koseki, Hironobu; Asahara, Tomohiko; Shida, Takayuki; Yoda, Itaru; Horiuchi, Hidehiko; Baba, Koumei; Osaki, Makoto

    2013-01-01

    Pin site infection is the most common and significant complication of external fixation. In this work, the efficacy of pins coated with titanium dioxide (TiO(2)) for inhibition of infection was compared with that of stainless steel control pins in an in vivo study. Pins contaminated with an identifiable Staphylococcus aureus strain were inserted into femoral bone in a rat model and exposed to ultraviolet A light for 30 minutes. On day 14, the animals were sacrificed and the bone and soft tissue around the pin were retrieved. The clinical findings and histological findings were evaluated in 60 samples. Clinical signs of infection were present in 76.7% of untreated pins, but in only 36.7% of TiO(2)-coated pins. The histological bone infection score and planimetric rate of occupation for bacterial colonies and neutrophils in the TiO(2)-coated pin group were lower than those in the control group. The bone-implant contact ratio of the TiO(2)-coated pin group was significantly higher (71.4%) than in the control pin group (58.2%). The TiO(2) was successful in decreasing infection both clinically and histomorphometrically. The photocatalytic bactericidal effect of TiO(2) is thought to be useful for inhibiting pin site infection after external fixation.

  2. Molecular Regulation of Photosynthetic Carbon Dioxide Fixation in Nonsulfur Purple Bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tabita, Fred Robert [The Ohio State Univ., Columbus, OH (United States)

    2015-12-01

    The overall objective of this project is to determine the mechanism by which a transcriptional activator protein affects CO2 fixation (cbb) gene expression in nonsulfur purple photosynthetic bacteria, with special emphasis to Rhodobacter sphaeroides and with comparison to Rhodopseudomonas palustris. These studies culminated in several publications which indicated that additional regulators interact with the master regulator CbbR in both R. sphaeroides and R. palustris. In addition, the interactive control of the carbon and nitrogen assimilatory pathways was studied and unique regulatory signals were discovered.

  3. Pathway of /sup 14/Co/sub 2/ fixation in marine algae

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, G V; Karekar, M D [Shivaji Univ., Kolhapur (India). Dept. of Botany

    1973-08-01

    Marine plants have a different metabolic environment which is likely to affect pathways of CO/sub 2/ fixation. It has been observed that in marine alga, Ulva lactuca, during short term light fixation of /sup 14/CO/sub 2/, besides PGA, an appreciable amount of activity was located in aspartate. This curious observation can now be explained on the basis of Hatch, Slack and Kortschak pathway of CO/sub 2/ fixation. In order to trace pathways of /sup 14/CO/sub 2/ in marine algae, a wide variety of algal specimens were exposed to NaH/sup 14/CO/sub 3/ in light and the products were analyzed. The algae selected were Ulva lactuca, Sargassum ilicifolium, Sphacelaria sp., Padina tetrastromatica, Chaetomorpha media and Enteromorpha tubulosa. It has been found that the pathways of CO/sub 2/ in the above marine algae differ from the conventional pattern recorded in Chlorella. The early labelling of aspartate and its subsequent utilization indicates that HSK pathway is operative in the marine algae. Malate synthesis is inhibited due to the effect of saline environment on the activity of malic dehydrogenase. Appreciable label in PGA is suggestive of the fact that Calvin and Bassham pathway as well as the HSK route are simultaneously operating. (auth)

  4. The C4-pathway of C-fixation in Spinacea oleracea. Pt. 1

    International Nuclear Information System (INIS)

    Boecher, M.; Kluge, M.

    1977-01-01

    Spinach leaf slices readily fix 14 C supplied from a suspension medium. The pattern of label distribution after 14 C-fixation in the light depends on the pH of the suspension medium. In the range of pH 3.5 leaf slices show labelling patterns of the C 3 type as do intact leaves or leaf slices incubated with 14 CO 2 in a gas cuvette. In contrast, if the tissue slices were suspended at pH 7.5 substantially more label appears in malate and other compounds of the C 4 -pathway. Under these conditions also the malate content of the tissue increases. The addition of NaHCO 3 at pH 3.5 increases the rate of C-fixation and nearly the whole fixed carbon is metabolized in the Calvin-cycle. The C-fixation is also increased, if NaHCO 3 is added at pH 7.5. Here both, the C 3 - and the C 4 -pathway contribute to an enhancement of the C-fixation. It is assumed, that increasing amounts of bicarbonate (substrate of PEP carboxylase) become available to the cells when the pH of the external medium is raised. This could increase an operation of the C 4 -pathway of C-fixation. This view is supported by the finding, that in contrast to low pH, the C-fixation at high pH results in a dominant labelling of the C 4 -atoms of malate. (orig.) [de

  5. CO2 (carbon dioxide) fixation by applying new chemical absorption-precipitation methods

    International Nuclear Information System (INIS)

    Park, Sangwon; Lee, Min-Gu; Park, Jinwon

    2013-01-01

    CO 2 (carbon dioxide) is the most common greenhouse gas and most of it is emitted from human activities. The methods for CO 2 emission reduction can be divided into physical, chemical, and biochemical methods. Among the physical and chemical methods, CCS (carbon capture and storage) is a well-known reducing technology. However, this method has many disadvantages including the required storage area. In general, CCS requires capture and storage processes. In this study, we propose a method for reusing the absorbed CO 2 either in nature or in industry. The emitted CO 2 was converted into CO 3 2− using a conversion solution, and then made into a carbonate by combining the conversion solution with metal ions at normal temperature and pressure. The resulting carbonate was analyzed using FT-IR (Fourier transform infrared spectroscopy) and XRD (X-ray diffraction). We verified the formation of a solid consisting of calcite and vaterite. In addition, the conversion solution that was used could be reused in the same process of CCS technology. Our study demonstrates a successful method of reducing and reusing emitted CO 2 , thereby making CO 2 a potential future resource. - Highlights: • This study focused on a new CO 2 fixation process method. • In CCS technology, the desorption process requires high thermal energy consumption. • This new method does not require a desorption process because the CO 2 is accomplished through CaCO 3 crystallization. • A new absorption method is possible instead of the conventional absorption-desorption process. • This is not only a rapid reaction for fixing CO 2 , but also economically feasible

  6. 14C fixation by leaves and leaf cell protoplasts of the submerged aquatic angiosperm Potamogeton lucens: Carbon dioxide or bicarbonate?

    International Nuclear Information System (INIS)

    Staal, M.; Elzenga, J.T.M.; Prins, H.B.A.

    1989-01-01

    Protoplasts were isolated from leaves of the aquatic angiosperm Potamogeton lucens L. The leaves utilize bicarbonate as a carbon source for photosynthesis, and show polarity; that is acidification of the periplasmic space of the lower, and alkalinization of the space near the upper leaf side. At present there are two models under consideration for this photosynthetic bicarbonate utilization process: conversion of bicarbonate into free carbon dioxide as a result of acidification and, second, a bicarbonate-proton symport across the plasma membrane. Carbon fixation of protoplasts was studied at different pH values and compared with that in leaf strips. Using the isotopic disequilibrium technique, it was established that carbon dioxide and not bicarbonate was the form in which DIC actually crossed the plasma membrane. It is concluded that there is probably no true bicarbonate transport system at the plasma membrane of these cells and that bicarbonate utilization in this species apparently rests on the conversion of bicarbonate into carbon dioxide. Experiments with acetazolamide, an inhibitor of periplasmic carbonic anhydrase, and direct measurements of carbonic anhydrase activity in intact leaves indicate that in this species the role of this enzyme for periplasmic conversion of bicarbonate into carbon dioxide is insignificant

  7. Community structure and soil pH determine chemoautotrophic carbon dioxide fixation in drained paddy soils.

    Science.gov (United States)

    Long, Xi-En; Yao, Huaiying; Wang, Juan; Huang, Ying; Singh, Brajesh K; Zhu, Yong-Guan

    2015-06-16

    Previous studies suggested that microbial photosynthesis plays a potential role in paddy fields, but little is known about chemoautotrophic carbon fixers in drained paddy soils. We conducted a microcosm study using soil samples from five paddy fields to determine the environmental factors and quantify key functional microbial taxa involved in chemoautotrophic carbon fixation. We used stable isotope probing in combination with phospholipid fatty acid (PLFA) and molecular approaches. The amount of microbial (13)CO2 fixation was determined by quantification of (13)C-enriched fatty acid methyl esters and ranged from 21.28 to 72.48 ng of (13)C (g of dry soil)(-1), and the corresponding ratio (labeled PLFA-C:total PLFA-C) ranged from 0.06 to 0.49%. The amount of incorporationof (13)CO2 into PLFAs significantly increased with soil pH except at pH 7.8. PLFA and high-throughput sequencing results indicated a dominant role of Gram-negative bacteria or proteobacteria in (13)CO2 fixation. Correlation analysis indicated a significant association between microbial community structure and carbon fixation. We provide direct evidence of chemoautotrophic C fixation in soils with statistical evidence of microbial community structure regulation of inorganic carbon fixation in the paddy soil ecosystem.

  8. Titanium-based zeolitic imidazolate framework for chemical fixation of carbon dioxide

    Science.gov (United States)

    A titanium-based zeolitic imidazolate framework (Ti-ZIF) with high surface area and porous morphology was synthesized and itsefficacy was demonstrated in the synthesis of cyclic carbonates from epoxides and carbon dioxide.

  9. Regulation of carbon dioxide fixation in facultatively autotrophic bacteria. A phisiological and genetical study.

    NARCIS (Netherlands)

    Meijer, Wilhelmus Gerhardus

    1990-01-01

    Autotrophic bactcria are capable of CO2 fixation via the Calvin cycle, emplofng energy derived from the oxidation of anorganic substrates (e.g. Hz), simple organic substrates (one-carbon compounds, e.g. methanol, formate), or from light. Ribulose-1,5-bisphospbate carboxylase/oxygenase (RuBisC/O),

  10. [Regulation of alternative CO[sub 2] fixation pathways in procaryotic and eucaryotic photosynthetic organisms

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    The major goal of this project is to determine how microorganisms regulate the assimilation of CO[sup 2] via pathways alternative to the usual Calvin reductive pentose phosphate scheme. In particular, we are interest in the molecular basis for switches in CO[sub 2] metabolic paths. Several earlier studies had indicated that purple nonsulfur photosynthetic bacteria assimilate significant amounts of CO[sub 2] via alternative non-Calvin routes. We have deleted the gene that encodes. RubisCo (ribulose bisphosphate carboxylase/oxygenase) in both the Rhodobacter sphaeroids and Rhodospirillum rubrum. The R. sphaeroides RubisCO deletion strain (strain 16) could not grow under photoheterotrophic conditions with malate as electron donor and CO[sub 2] as the electron acceptor; however the R. rub RubisCO deletion strain (strain I-19) could. Over the past year we have sought to physiologically characterize strain 16PHC. We found that, 16PHC exhibited rates of whole-cell CO[sub 2] fixation which were significantly higher than strain 16. Strain 16PHC could not grow photolithoautotrophically in a CO[sub 2] atmosphere; however, CO[sub 2] fixation catalyzed by photoheterotrophically grown 16PHC was repressed by the addition of DMSO. Likewise, we found that cells initially grown in the presence of DMSO could induce the CO[sub 2] fixation system when DMSO was removed. Thus, these results suggested that both PHC and I-19 could be used to study alternative CO[sub 2] fixation reactions and their significance in R. sphaexoides and R. rubrum.

  11. Biomechanical testing of zirconium dioxide osteosynthesis system for Le Fort I advancement osteotomy fixation.

    Science.gov (United States)

    Hingsammer, Lukas; Grillenberger, Markus; Schagerl, Martin; Malek, Michael; Hunger, Stefan

    2018-01-01

    The following work is the first evaluating the applicability of 3D printed zirconium dioxide ceramic miniplates and screws to stabilize maxillary segments following a Le-Fort I advancement surgery. Conventionally used titanium and individual fabricated zirconium dioxide miniplates were biomechanically tested and compared under an occlusal load of 120N and 500N using 3D finite element analysis. The overall model consisted of 295,477 elements. Under an occlusal load of 500N a safety factor before plastic deformation respectively crack of 2.13 for zirconium dioxide and 4.51 for titanium miniplates has been calculated. From a biomechanical point of view 3D printed ZrO 2 mini-plates and screws are suggested to constitute an appropriate patient specific and metal-free solution for maxillary stabilization after Le Fort I osteotomy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Photosynthetic carbon fixation pathways in Zostera marina and three Florida seagrasses

    Energy Technology Data Exchange (ETDEWEB)

    Beer, S.; Wetzel, R.G.

    1982-06-01

    The photosynthetic carbon fixation pathways of four seagrass species, Zostera marina L. from Alaska and Thalassia testudinum Banks ex Konig, Syringodium filiforme Kutz. and Halodule wrightii Aschers. from the Gulf of Mexico, were investigated with a /sup 14/C pulse-chase technique. All species were found to be principally of the C/sub 3/ type. However, Thalassia and Halodule had higher initial incorporation rates into organic acids than is typical for terrestrial C/sub 3/ plants. Of 11 seagrass species investigated thus far for C/sub 3/ or C/sub 4/ metabolism using this technique, 10 were found to be principally of the C/sub 3/ type while only one exhibited C/sub 4/ metabolism.

  13. Effects of elevated carbon dioxide concentration on growth and nitrogen fixation in Alnus glutinosa in a long-term field experiment

    Energy Technology Data Exchange (ETDEWEB)

    Temperton, V. M.; Jackson, G.; Barton, C. V. M.; Jarvis, P. G. [Edinburgh Univ., Inst. of Ecology and Resource Management, Edinburgh (United Kingdom); Grayston, S. J. [Macaulay Land Use Research Inst., Plant-Soil Interaction Group, Aberdeen (United Kingdom)

    2003-10-01

    Total biomass, relative growth rate, net assimilation rate, leaf area and net photosynthetic rate of nitrogen-fixing were measured in common alder trees, grown for three years in open-top chambers in the presence of either ambient or elevated atmospheric carbon dioxide, and in two soil nitrogen regimes: i.e. full nutrient solution or no fertilizer. The objective was to clarify the relationship between elevated carbon dioxide and the rate of nitrogen fixation of nodulated trees growing under field conditions. Results showed that growth in elevated carbon dioxide stimulated net photosynthesis and total biomass accumulation. However, relative growth rate was not significantly affected by elevated carbon dioxide. Leaf area and leaf phosphorus concentration were also unaffected. Nodule mass on roots of unfertilized trees exposed to elevated carbon dioxide increased, compared with fertilized trees exposed to ambient carbon dioxide levels. Since neither in the fertilized, nor the unfertilized trees was there any evidence of effects on growth, biomass and photosynthesis that could be attributed to the interaction of fertilizer and elevated carbon dioxide interaction, it was concluded that both types exhibit similar carbon dioxide-induced growth and photosynthetic enhancements. 40 refs., 5 tabs., 3 figs.

  14. Effects of elevated carbon dioxide concentration on growth and nitrogen fixation in Alnus glutinosa in a long-term field experiment

    International Nuclear Information System (INIS)

    Temperton, V. M.; Jackson, G.; Barton, C. V. M.; Jarvis, P. G.; Grayston, S. J.

    2003-01-01

    Total biomass, relative growth rate, net assimilation rate, leaf area and net photosynthetic rate of nitrogen-fixing were measured in common alder trees, grown for three years in open-top chambers in the presence of either ambient or elevated atmospheric carbon dioxide, and in two soil nitrogen regimes: i.e. full nutrient solution or no fertilizer. The objective was to clarify the relationship between elevated carbon dioxide and the rate of nitrogen fixation of nodulated trees growing under field conditions. Results showed that growth in elevated carbon dioxide stimulated net photosynthesis and total biomass accumulation. However, relative growth rate was not significantly affected by elevated carbon dioxide. Leaf area and leaf phosphorus concentration were also unaffected. Nodule mass on roots of unfertilized trees exposed to elevated carbon dioxide increased, compared with fertilized trees exposed to ambient carbon dioxide levels. Since neither in the fertilized, nor the unfertilized trees was there any evidence of effects on growth, biomass and photosynthesis that could be attributed to the interaction of fertilizer and elevated carbon dioxide interaction, it was concluded that both types exhibit similar carbon dioxide-induced growth and photosynthetic enhancements. 40 refs., 5 tabs., 3 figs

  15. The teraton challenge. A review of fixation and transformation of carbon dioxide

    DEFF Research Database (Denmark)

    Mikkelsen, Mette; Jørgensen, Mikkel; Krebs, Frederik C

    2010-01-01

    The increase in atmospheric carbon dioxide is linked to climate changes; hence there is an urgent need to reduce the accumulation of CO2 in the atmosphere. The utilization of CO2 as a raw material in the synthesis of chemicals and liquid energy carriers offers a way to mitigate the increasing CO2...... buildup. This review covers six important CO2 transformations namely: chemical transformations, photochemical reductions, chemical and electrochemical reductions, biological conversions, reforming and inorganic transformations. Furthermore, the vast research area of carbon capture and storage is reviewed...

  16. Effects of sulfur dioxide on nitrogen fixation, carbon partitioning, and yield components in snapbean

    International Nuclear Information System (INIS)

    Griffith, S.M.; Campbell, W.F.

    1987-01-01

    The air pollutant SO 2 is known to affect plant biochemistry and physiology, although very little is known about its effects on N 2 -fixation in legumes. This study sought to determine if N 2 -fixation, C partitioning, and plant productivity of snapbean (Phaseolus vulgaris L.) were affected under short-term, low-level SO 2 exposures. Plants were exposed, 29 d after planting (7 d before anthesis), to 0, 18, and 36 μmol SO 2 m -3 for 4 h d -1 for 5 d in a fumigation chamber. On the last day of SO 2 treatment, plants were also exposed to 14 CO 2 to determine changes in C partitioning patterns. At these concentrations, there was no visible damage to plant tissue and no significant changes in dry weight or yield components. Only the 36 μmol SO 2 m -3 treatment reduced C 2 H 2 reduction rates, but recovery to near control rates occurred within 24 h after SO 2 removal. Leaves of plants treated with 18 μmol SO 2 m -3 exported more of their total assimilated 14 C than control plants, while those treated with 36 μmol SO 2 m -3 retained greater amounts. Retention of 14 C at the 36 μmol SO 2 m -3 level may account for the inhibition of C 2 H 2 -reduction because of less photosynthate arriving at the root nodules. These data suggest that SO 2 levels that do not cause visible injury may interfere with C metabolism and transport in snapbean

  17. Geochemical fixation of carbon dioxide in the environment. Chikyu kagakuteki kenchi kara no tansan'en ni yoru nisanka tanso no kotei

    Energy Technology Data Exchange (ETDEWEB)

    Ishikawa, M [Mitsubishi Research Institute, Inc., Tokyo (Japan)

    1993-06-15

    The Mitsubishi Research Institute has investigated and discussed the current situation and the future direction of the studies on geochemical fixation of carbon dioxide by means of carbonates. This paper summarizes the results thereof. The discussion items are listed as follows: The current status of land areas active in carbonate fixation (lake-bottom deposits, sabkha, dry areas, carbonate rock areas); investigation on sea areas active in carbonate fixation (coral reef areas, land shelf areas, open sea areas, and mantle); development of environmental change analyzing technologies (measurement of ancient environments, measurement of fixation ages, development of local area analysis, measurement of diagenetic structures, origin and behavior of trace elements in carbonate substances, and measurement of the current environments); evaluation on fixation ability of carbon sinks (circulation and fixation in coral reef ecosystems, calcification mechanisms in calcareous algae, dissolution processes at ocean bottoms, and inorganic chemical measurement); and investigation on simulation models (solution chemistry equilibrium model and global carbonate circulation model). 4 refs., 1 tab.

  18. An engineered Calvin-Benson-Bassham cycle for carbon dioxide fixation in Methylobacterium extorquens AM1.

    Science.gov (United States)

    von Borzyskowski, Lennart Schada; Carrillo, Martina; Leupold, Simeon; Glatter, Timo; Kiefer, Patrick; Weishaupt, Ramon; Heinemann, Matthias; Erb, Tobias J

    2018-04-03

    Organisms are either heterotrophic or autotrophic, meaning that they cover their carbon requirements by assimilating organic compounds or by fixing inorganic carbon dioxide (CO 2 ). The conversion of a heterotrophic organism into an autotrophic one by metabolic engineering is a long-standing goal in synthetic biology and biotechnology, because it ultimately allows for the production of value-added compounds from CO 2 . The heterotrophic Alphaproteobacterium Methylobacterium extorquens AM1 is a platform organism for a future C1-based bioeconomy. Here we show that M. extorquens AM1 provides unique advantages for establishing synthetic autotrophy, because energy metabolism and biomass formation can be effectively separated from each other in the organism. We designed and realized an engineered strain of M. extorquens AM1 that can use the C1 compound methanol for energy acquisition and forms biomass from CO 2 by implementation of a heterologous Calvin-Benson-Bassham (CBB) cycle. We demonstrate that the heterologous CBB cycle is active, confers a distinct phenotype, and strongly increases viability of the engineered strain. Metabolic 13 C-tracer analysis demonstrates the functional operation of the heterologous CBB cycle in M. extorquens AM1 and comparative proteomics of the engineered strain show that the host cell reacts to the implementation of the CBB cycle in a plastic way. While the heterologous CBB cycle is not able to support full autotrophic growth of M. extorquens AM1, our study represents a further advancement in the design and realization of synthetic autotrophic organisms. Copyright © 2018. Published by Elsevier Inc.

  19. Bioreactors for fixation and effective utilization of carbon dioxide gas. Tansan gas no koteiter dot yuko riyo no tame no bio reactor

    Energy Technology Data Exchange (ETDEWEB)

    Miyamoto, K. (Osaka University, Osaka (Japan). Faculty of Pharmaceutical Science); Benemann, J. (California University, CA (USA))

    1991-06-01

    As for a preventive countermeasure against the global warming, experiments and studies have been conducted on the bioreactors to fix carbon dioxide gas recovered from the concentric and large scale generating sources such as thermal power plamts in a form of carbohydrate by means of the culture of microbial algae. By using the Vertical Tube Reactors (VTR) culturing apparatus, a variety of microbial algae were cultivated and experiments were performed on the relationship of biomass productivity and absorption rate of carbon dioxide gas indoors and outdoors. Consequently, it was found that when the flow rate of carbon dioxide gas is adjusted to make the biomass productivity of filament type Nostoc maximum,the inlet and outlet concentrations of carbon dioxide gas were 0.7% and 0.05% respectively with the absorption rate of more than 90%. From the standpoint of fixation and effective utilization of carbon dioxide gas, the above rate of removal is one of the important parameters and it will be necessary in future to compare the rates of removal of carbon dioxide gas among various types of bioreactors as a function of operating condition. 9 refs., 6 figs., 2 tabs.

  20. Genes and pathways for CO2 fixation in the obligate, chemolithoautotrophic acidophile, Acidithiobacillus ferrooxidans, Carbon fixation in A. ferrooxidans

    Directory of Open Access Journals (Sweden)

    Esparza Mario

    2010-08-01

    Full Text Available Abstract Background Acidithiobacillus ferrooxidans is chemolithoautotrophic γ-proteobacterium that thrives at extremely low pH (pH 1-2. Although a substantial amount of information is available regarding CO2 uptake and fixation in a variety of facultative autotrophs, less is known about the processes in obligate autotrophs, especially those living in extremely acidic conditions, prompting the present study. Results Four gene clusters (termed cbb1-4 in the A. ferrooxidans genome are predicted to encode enzymes and structural proteins involved in carbon assimilation via the Calvin-Benson-Bassham (CBB cycle including form I of ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO, EC 4.1.1.39 and the CO2-concentrating carboxysomes. RT-PCR experiments demonstrated that each gene cluster is a single transcriptional unit and thus is an operon. Operon cbb1 is divergently transcribed from a gene, cbbR, encoding the LysR-type transcriptional regulator CbbR that has been shown in many organisms to regulate the expression of RubisCO genes. Sigma70-like -10 and -35 promoter boxes and potential CbbR-binding sites (T-N11-A/TNA-N7TNA were predicted in the upstream regions of the four operons. Electrophoretic mobility shift assays (EMSAs confirmed that purified CbbR is able to bind to the upstream regions of the cbb1, cbb2 and cbb3 operons, demonstrating that the predicted CbbR-binding sites are functional in vitro. However, CbbR failed to bind the upstream region of the cbb4 operon that contains cbbP, encoding phosphoribulokinase (EC 2.7.1.19. Thus, other factors not present in the assay may be required for binding or the region lacks a functional CbbR-binding site. The cbb3 operon contains genes predicted to encode anthranilate synthase components I and II, catalyzing the formation of anthranilate and pyruvate from chorismate. This suggests a novel regulatory connection between CO2 fixation and tryptophan biosynthesis. The presence of a form II Rubis

  1. Comparison of plants with C3 and C4 carbon fixation pathways for remediation of polycyclic aromatic hydrocarbon contaminated soils

    OpenAIRE

    Sivaram, Anithadevi Kenday; Logeshwaran, Panneerselvan; Subashchandrabose, Suresh R.; Lockington, Robin; Naidu, Ravi; Megharaj, Mallavarapu

    2018-01-01

    The phytoremediation technique has been demonstrated to be a viable option for the remediation of polycyclic aromatic hydrocarbons (PAHs) contaminated sites. This study evaluated the potential applicability of plants with C3 and C4 carbon fixation pathways for the phytoremediation of recalcitrant high molecular weight (HMW) PAHs contaminated soil. A 60 and 120-day greenhouse study was conducted which showed higher degradation of HMW PAHs in soil grown with C4 plants when compared to C3 plants...

  2. Potential role of multiple carbon fixation pathways during lipid accumulation in Phaeodactylum tricornutum

    Directory of Open Access Journals (Sweden)

    Valenzuela Jacob

    2012-06-01

    Full Text Available Abstract Background Phaeodactylum tricornutum is a unicellular diatom in the class Bacillariophyceae. The full genome has been sequenced (P. tricornutum gene expression profiles during nutrient-deprivation and lipid-accumulation, cell cultures were grown with a nitrate to phosphate ratio of 20:1 (N:P and whole-genome transcripts were monitored over time via RNA-sequence determination. Results The specific Nile Red (NR fluorescence (NR fluorescence per cell increased over time; however, the increase in NR fluorescence was initiated before external nitrate was completely exhausted. Exogenous phosphate was depleted before nitrate, and these results indicated that the depletion of exogenous phosphate might be an early trigger for lipid accumulation that is magnified upon nitrate depletion. As expected, many of the genes associated with nitrate and phosphate utilization were up-expressed. The diatom-specific cyclins cyc7 and cyc10 were down-expressed during the nutrient-deplete state, and cyclin B1 was up-expressed during lipid-accumulation after growth cessation. While many of the genes associated with the C3 pathway for photosynthetic carbon reduction were not significantly altered, genes involved in a putative C4 pathway for photosynthetic carbon assimilation were up-expressed as the cells depleted nitrate, phosphate, and exogenous dissolved inorganic carbon (DIC levels. P. tricornutum has multiple, putative carbonic anhydrases, but only two were significantly up-expressed (2-fold and 4-fold at the last time point when exogenous DIC levels had increased after the cessation of growth. Alternative pathways that could utilize HCO3- were also suggested by the gene expression profiles (e.g., putative propionyl-CoA and methylmalonyl-CoA decarboxylases. Conclusions The results indicate that P. tricornutum continued carbon dioxide reduction when population growth was arrested and different carbon-concentrating mechanisms were used dependent upon exogenous

  3. Biochemical studies on the effect of fluoride on higher plants. 3. The effect of fluoride on dark carbon dioxide fixation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, S F; Miller, G W

    1963-01-01

    Dark CO/sub 2/ fixation and phosphoenolpyruvate-carboxylase activity were studied in fluoride-necrotic and control soya-bean leaves. Necrotic leaves had a higher rate of dark CO/sub 2/ fixation than control leaves both in vivo and in vitro (phosphoenolpyruvate carboxylase). Results suggested that the accumulation of organic acids and amino acids in necrotic leaves resulted from an increased rate of dark CO/sub 2/ fixation. The possible role of fluoride in stimulating the carboxylation and its implication to necrosis are discussed.

  4. Fiscal 1995 investigation on biological fixation of carbon dioxide; 1995 nendo seibutsuteki CO2 kotei ni kansuru chosa hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    To cope with the global warming caused by CO2, an investigation was conducted into biological fixation. It is necessary to make a many-sided and comprehensive study on the mechanism of CO2 fixation, the scale (area and carbon holding density), the rate and the environmental impact of the introduction of the technology and the technical problems, and to make a quantitative evaluation of each of the methods in order to make them practical proposals. The global ecosystem is classified into the land biota and ocean biota, and each typical ecosystem was surveyed in terms of the surface area, the carbon holding amount (presently existing amount), the net primary production amount, the required nutrient salt amount, the transpiration rate, etc. Next, a discussion was made on the increasing effect of the carbon fixation amount by changing the present ecosystem from the aspect of scale and rate. At the same time, a study was carried out of energy efficiency, economical efficiency and problems. Last, elementary technology was taken up which seems to be important for implementing measures for the biological carbon fixation. As to the ocean, it is necessary to obtain information, which is not sufficient to utilize marine biota for CO2 fixation, especially on the mechanism of depth-direction transfer of organism and its quantitative grasp. As to the land, one of the measures is conversion of the ecosystem where the amount of carbon fixed is small to the ecosystem where the amount is large. 249 refs., 58 figs., 51 tabs.

  5. [Regulation of alternative CO{sub 2} fixation pathways in procaryotic and eucaryotic photosynthetic organisms]. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    1992-12-31

    The major goal of this project is to determine how microorganisms regulate the assimilation of CO{sup 2} via pathways alternative to the usual Calvin reductive pentose phosphate scheme. In particular, we are interest in the molecular basis for switches in CO{sub 2} metabolic paths. Several earlier studies had indicated that purple nonsulfur photosynthetic bacteria assimilate significant amounts of CO{sub 2} via alternative non-Calvin routes. We have deleted the gene that encodes. RubisCo (ribulose bisphosphate carboxylase/oxygenase) in both the Rhodobacter sphaeroids and Rhodospirillum rubrum. The R. sphaeroides RubisCO deletion strain (strain 16) could not grow under photoheterotrophic conditions with malate as electron donor and CO{sub 2} as the electron acceptor; however the R. rub RubisCO deletion strain (strain I-19) could. Over the past year we have sought to physiologically characterize strain 16PHC. We found that, 16PHC exhibited rates of whole-cell CO{sub 2} fixation which were significantly higher than strain 16. Strain 16PHC could not grow photolithoautotrophically in a CO{sub 2} atmosphere; however, CO{sub 2} fixation catalyzed by photoheterotrophically grown 16PHC was repressed by the addition of DMSO. Likewise, we found that cells initially grown in the presence of DMSO could induce the CO{sub 2} fixation system when DMSO was removed. Thus, these results suggested that both PHC and I-19 could be used to study alternative CO{sub 2} fixation reactions and their significance in R. sphaexoides and R. rubrum.

  6. Enantioselective small molecule synthesis by carbon dioxide fixation using a dual Brønsted acid/base organocatalyst.

    Science.gov (United States)

    Vara, Brandon A; Struble, Thomas J; Wang, Weiwei; Dobish, Mark C; Johnston, Jeffrey N

    2015-06-17

    Carbon dioxide exhibits many of the qualities of an ideal reagent: it is nontoxic, plentiful, and inexpensive. Unlike other gaseous reagents, however, it has found limited use in enantioselective synthesis. Moreover, unprecedented is a tool that merges one of the simplest biological approaches to catalysis-Brønsted acid/base activation-with this abundant reagent. We describe a metal-free small molecule catalyst that achieves the three component reaction between a homoallylic alcohol, carbon dioxide, and an electrophilic source of iodine. Cyclic carbonates are formed enantioselectively.

  7. Titanium dioxide nanoparticles activate IL8-related inflammatory pathways in human colonic epithelial Caco-2 cells

    Science.gov (United States)

    Krüger, Kristin; Cossais, François; Neve, Horst; Klempt, Martin

    2014-05-01

    Nanosized titanium dioxide (TiO2) particles are widely used as food additive or coating material in products of the food and pharmaceutical industry. Studies on various cell lines have shown that TiO2 nanoparticles (NPs) induced the inflammatory response and cytotoxicity. However, the influences of TiO2 NPs' exposure on inflammatory pathways in intestinal epithelial cells and their differentiation have not been investigated so far. This study demonstrates that TiO2 NPs with particle sizes ranging between 5 and 10 nm do not affect enterocyte differentiation but cause an activation of inflammatory pathways in the human colon adenocarcinoma cell line Caco-2. 5 and 10 nm NPs' exposures transiently induce the expression of ICAM1, CCL20, COX2 and IL8, as determined by quantitative PCR, whereas larger particles (490 nm) do not. Further, using nuclear factor (NF)-κB reporter gene assays, we show that NP-induced IL8 mRNA expression occurs, in part, through activation of NF-κB and p38 mitogen-activated protein kinase pathways.

  8. Basic research on the carbon dioxide fixation using seaweed. Kaisorui no tansan gas kotei ni kansuru kiso kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Yamamoto, M.; Ishihara, T. (The Kansai Electric Power Co. Inc., Osaka (Japan))

    1993-08-25

    Study was made for grasping the basic data of CO2 fixation technology by seaweed. The photosynthesis under the sea, which is different from that on the land, is judged to be made by taking in HCO3[sup -] and converting it into CO2 inside the plant. Porphyra yezoensis which is seaweed is cultivated as comestible. With a rise in CO2 content, the growth in length of leaves was observed to be accelerated through ventilating Porphyra yezoensis with the three test types of air which respectively contained 350ppm (atmospheric CO2 content), 1000ppm and 1600ppm CO2. As a result of measuring the photosynthesis speed by the generated quantity of O2, it was heightened with a rise in dissolved inorganic carbonic acid content of the sea water. Measurement was also made of daily fluctuation in calcification speed by Corallina officinalis capable of calcification by ventilating it with 350ppm and 1600ppm CO2. In case of 1600ppm, the sedimentation of CaCO3 was prevented. In case of 350ppm, the sedimentation was quantitatively larger during the bright period than that during the dark period. The growth of Gracilaria gigas which is an agar material was compared by changing the above CO2 levels. In case of 1600ppm, the weight grew to 2.3 times in 20 days. 16 figs., 2 tabs.

  9. Metabolic Pathways Involved in Carbon Dioxide Enhanced Heat Tolerance in Bermudagrass

    Directory of Open Access Journals (Sweden)

    Jingjin Yu

    2017-09-01

    Full Text Available Global climate changes involve elevated temperature and CO2 concentration, imposing significant impact on plant growth of various plant species. Elevated temperature exacerbates heat damages, but elevated CO2 has positive effects on promoting plant growth and heat tolerance. The objective of this study was to identify metabolic pathways affected by elevated CO2 conferring the improvement of heat tolerance in a C4 perennial grass species, bermudagrass (Cynodon dactylon Pers.. Plants were planted under either ambient CO2 concentration (400 μmol⋅mol-1 or elevated CO2 concentration (800 μmol⋅mol-1 and subjected to ambient temperature (30/25°C, day/night or heat stress (45/40°C, day/night. Elevated CO2 concentration suppressed heat-induced damages and improved heat tolerance in bermudagrass. The enhanced heat tolerance under elevated CO2 was attributed to some important metabolic pathways during which proteins and metabolites were up-regulated, including light reaction (ATP synthase subunit and photosystem I reaction center subunit and carbon fixation [(glyceraldehyde-3-phosphate dehydrogenase, GAPDH, fructose-bisphosphate aldolase, phosphoglycerate kinase, sedoheptulose-1,7-bisphosphatase and sugars of photosynthesis, glycolysis (GAPDH, glucose, fructose, and galactose and TCA cycle (pyruvic acid, malic acid and malate dehydrogenase of respiration, amino acid metabolism (aspartic acid, methionine, threonine, isoleucine, lysine, valine, alanine, and isoleucine as well as the GABA shunt (GABA, glutamic acid, alanine, proline and 5-oxoproline. The up-regulation of those metabolic processes by elevated CO2 could at least partially contribute to the improvement of heat tolerance in perennial grass species.

  10. Oxidation of nonylphenol and octylphenol by manganese dioxide: Kinetics and pathways

    International Nuclear Information System (INIS)

    Lu, Zhijiang; Gan, Jay

    2013-01-01

    Due to their potent estrogenicity and ubiquitous occurrence, non-ionic surfactant metabolites nonylphenol (NP) and octylphenol (OP) are of significant concern. Abiotic chemical oxidation by naturally abundant metal oxides may be an important route of their environmental attenuation, but is poorly understood. We investigated the reaction kinetics and pathways of NP and OP with MnO 2 . At pH 5.5 and 100 mg/L δ-MnO 2 , 92, 84 and 76% of 4-n-NP, 4-tert-OP and technical nonylphenol (tNP) was transformed in 90 min, respectively. A further experiment using a Mn-containing soil and Mn-removed soil confirmed that soil MnO 2 caused NP removal. Multiple reaction products, including hydroquinone, hydroxylated products, dimers and trimers were identified through fragmentation analysis by GC–MS/MS and UPLC–MS/MS, allowing the construction of tentative pathways. This study suggested that abiotic oxidation by MnO 2 may contribute to the dissipation of tNP, 4-n-NP, 4-tert-OP and their analogues in the natural environment. Highlights: •The oxidation of nonylphenol and octylphenol by manganese dioxide was efficient and pH dependent. •The importance of soil MnO 2 was further confirmed by experiment using Mn-containing soil. •The reaction in environment is substantially slower than with synthetic MnO 2 . •The oxidation was inhibited by metal ions and enhanced by humic acids. •Reaction pathway is proposed based on reaction intermediates identified. -- Naturally occurring MnO 2 may contribute significantly to the attenuation of nonylphenol and octylphenol in soil, water and sediment

  11. Robust Control of PEP Formation Rate in the Carbon Fixation Pathway of C4 Plants by a Bi-functional Enzyme

    Directory of Open Access Journals (Sweden)

    Hart Yuval

    2011-10-01

    Full Text Available Abstract Background C4 plants such as corn and sugarcane assimilate atmospheric CO2 into biomass by means of the C4 carbon fixation pathway. We asked how PEP formation rate, a key step in the carbon fixation pathway, might work at a precise rate, regulated by light, despite fluctuations in substrate and enzyme levels constituting and regulating this process. Results We present a putative mechanism for robustness in C4 carbon fixation, involving a key enzyme in the pathway, pyruvate orthophosphate dikinase (PPDK, which is regulated by a bifunctional enzyme, Regulatory Protein (RP. The robust mechanism is based on avidity of the bifunctional enzyme RP to its multimeric substrate PPDK, and on a product-inhibition feedback loop that couples the system output to the activity of the bifunctional regulator. The model provides an explanation for several unusual biochemical characteristics of the system and predicts that the system's output, phosphoenolpyruvate (PEP formation rate, is insensitive to fluctuations in enzyme levels (PPDK and RP, substrate levels (ATP and pyruvate and the catalytic rate of PPDK, while remaining sensitive to the system's input (light levels. Conclusions The presented PPDK mechanism is a new way to achieve robustness using product inhibition as a feedback loop on a bifunctional regulatory enzyme. This mechanism exhibits robustness to protein and metabolite levels as well as to catalytic rate changes. At the same time, the output of the system remains tuned to input levels.

  12. Assessing carbon dioxide removal through global and regional ocean alkalinization under high and low emission pathways

    Science.gov (United States)

    Lenton, Andrew; Matear, Richard J.; Keller, David P.; Scott, Vivian; Vaughan, Naomi E.

    2018-04-01

    Atmospheric carbon dioxide (CO2) levels continue to rise, increasing the risk of severe impacts on the Earth system, and on the ecosystem services that it provides. Artificial ocean alkalinization (AOA) is capable of reducing atmospheric CO2 concentrations and surface warming and addressing ocean acidification. Here, we simulate global and regional responses to alkalinity (ALK) addition (0.25 PmolALK yr-1) over the period 2020-2100 using the CSIRO-Mk3L-COAL Earth System Model, under high (Representative Concentration Pathway 8.5; RCP8.5) and low (RCP2.6) emissions. While regionally there are large changes in alkalinity associated with locations of AOA, globally we see only a very weak dependence on where and when AOA is applied. On a global scale, while we see that under RCP2.6 the carbon uptake associated with AOA is only ˜ 60 % of the total, under RCP8.5 the relative changes in temperature are larger, as are the changes in pH (140 %) and aragonite saturation state (170 %). The simulations reveal AOA is more effective under lower emissions, therefore the higher the emissions the more AOA is required to achieve the same reduction in global warming and ocean acidification. Finally, our simulated AOA for 2020-2100 in the RCP2.6 scenario is capable of offsetting warming and ameliorating ocean acidification increases at the global scale, but with highly variable regional responses.

  13. ¹³C metabolic flux analysis identifies an unusual route for pyruvate dissimilation in mycobacteria which requires isocitrate lyase and carbon dioxide fixation.

    Directory of Open Access Journals (Sweden)

    Dany J V Beste

    2011-07-01

    Full Text Available Mycobacterium tuberculosis requires the enzyme isocitrate lyase (ICL for growth and virulence in vivo. The demonstration that M. tuberculosis also requires ICL for survival during nutrient starvation and has a role during steady state growth in a glycerol limited chemostat indicates a function for this enzyme which extends beyond fat metabolism. As isocitrate lyase is a potential drug target elucidating the role of this enzyme is of importance; however, the role of isocitrate lyase has never been investigated at the level of in vivo fluxes. Here we show that deletion of one of the two icl genes impairs the replication of Mycobacterium bovis BCG at slow growth rate in a carbon limited chemostat. In order to further understand the role of isocitrate lyase in the central metabolism of mycobacteria the effect of growth rate on the in vivo fluxes was studied for the first time using ¹³C-metabolic flux analysis (MFA. Tracer experiments were performed with steady state chemostat cultures of BCG or M. tuberculosis supplied with ¹³C labeled glycerol or sodium bicarbonate. Through measurements of the ¹³C isotopomer labeling patterns in protein-derived amino acids and enzymatic activity assays we have identified the activity of a novel pathway for pyruvate dissimilation. We named this the GAS pathway because it utilizes the Glyoxylate shunt and Anapleurotic reactions for oxidation of pyruvate, and Succinyl CoA synthetase for the generation of succinyl CoA combined with a very low flux through the succinate--oxaloacetate segment of the tricarboxylic acid cycle. We confirm that M. tuberculosis can fix carbon from CO₂ into biomass. As the human host is abundant in CO₂ this finding requires further investigation in vivo as CO₂ fixation may provide a point of vulnerability that could be targeted with novel drugs. This study also provides a platform for further studies into the metabolism of M. tuberculosis using ¹³C-MFA.

  14. Prokaryotic responses to ammonium and organic carbon reveal alternative CO2 fixation pathways and importance of alkaline phosphatase in the mesopelagic North Atlantic

    Directory of Open Access Journals (Sweden)

    Federico Baltar

    2016-10-01

    Full Text Available To decipher the response of mesopelagic prokaryotic communities to input of nutrients, we tracked changes in prokaryotic abundance, extracellular enzymatic activities, heterotrophic production, dark dissolved inorganic carbon (DIC fixation, community composition (16S rRNA sequencing and community gene expression (metatranscriptomics in 3 microcosm experiments with water from the mesopelagic North Atlantic. Responses in 3 different treatments amended with thiosulfate, ammonium or organic matter (i.e. pyruvate plus acetate were compared to unamended controls. The strongest stimulation was found in the organic matter enrichments, where all measured rates increased >10-fold. Strikingly, in the organic matter treatment, the dark DIC fixation rates —assumed to be related to autotrophic metabolisms— were equally stimulated as all the other heterotrophic-related parameters. This increase in DIC fixation rates was paralleled by an up-regulation of genes involved in DIC assimilation via anaplerotic pathways. Alkaline phosphatase was the metabolic rate most strongly stimulated and its activity seemed to be related to cross-activation by nonpartner histidine kinases, and/or the activation of genes involved in the regulation of elemental balance during catabolic processes. These findings suggest that episodic events such as strong sedimentation of organic matter into the mesopelagic might trigger rapid increases of originally rare members of the prokaryotic community, enhancing heterotrophic and autotrophic carbon uptake rates, ultimately affecting carbon cycling. Our experiments highlight a number of fairly unstudied microbial processes of potential importance in mesopelagic waters that require future attention.

  15. The effects of environmental physical factors on the microbial communities and the distribution of different CO2 fixation pathways in a limestone landscape

    Science.gov (United States)

    Wun, S. R.; Huang, T. Y.; Hsu, B. M.; Fan, C. W.

    2017-12-01

    We aimed to study the effects of physical factors on the relative abundance of bacteria and their preferential admissions of autotrophic CO2 fixation pathways after subjected to environmental long-term influence. The Narrow-Sky located in upper part of Takangshan is a small gulch of Pleistocene coralline limestone formation in southern Taiwan. The physical parameters such as illumination, humidity, and temperature were varied largely in habitats around the gulch, namely on the limestone wall at the opening of gulch, on the coordinate ground soil, on the wall inside the gulch, and the water drip from limestone wall. The total organic carbon was measured in solid samples to evaluate the biomass of the habitats. A metagenomic approach was carried out to reveal their microbial community structure. After the metagenomic library of operational taxonomic units (OTUs) was constructed, a BLAST search by "nomenclature of bacteria" instead of sequences between the OTU libraries and KEGG database was carried out to generate libraries of "model microbial communities", which the complete genomes of the entire bacterial populations were available. Our results showed the biomass of habitats in the opening of gulch was twice higher than the inside, suggesting the illumination played an important role in biosynthesis. In quantitative comparison in key enzymes of CO2 fixation pathways by model communities, 70% to 90% of bacteria possessed key enzymes of Fuchs-Holo cycle, while only 5% to 20% of bacteria contained key enzymes of Calvin-Benson cycle. The key enzymes for hydroxypropionate/ hydroxybutyrate and dicarboxylate/ 4-hydroxybutyrate cycles were not found in this study. In the water sample, approximate 10% of bacteria consisted of the key enzyme for Arnon-Buchanan cycle. Less than 2% of bacteria in all habitats take the reductive acetyl-CoA cycle for CO2 fixation. This study provides a novel method to study biosynthetic process of microbial communities in natural habitats.

  16. Sequestration of carbon dioxide with hydrogen to useful products

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Michael W. W.; Kelly, Robert M.; Hawkins, Aaron B.; Menon, Angeli Lal; Lipscomb, Gina Lynette Pries; Schut, Gerrit Jan

    2017-03-07

    Provided herein are genetically engineered microbes that include at least a portion of a carbon fixation pathway, and in one embodiment, use molecular hydrogen to drive carbon dioxide fixation. In one embodiment, the genetically engineered microbe is modified to convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof at levels greater than a control microbe. Other products may also be produced. Also provided herein are cell free compositions that convert acetyl CoA, molecular hydrogen, and carbon dioxide to 3-hydroxypropionate, 4-hydroxybutyrate, acetyl CoA, or the combination thereof. Also provided herein are methods of using the genetically engineered microbes and the cell free compositions.

  17. Evidence of carbon fixation pathway in a bacterium from candidate phylum SBR1093 revealed with genomic analysis.

    Directory of Open Access Journals (Sweden)

    Zhiping Wang

    Full Text Available Autotrophic CO2 fixation is the most important biotransformation process in the biosphere. Research focusing on the diversity and distribution of relevant autotrophs is significant to our comprehension of the biosphere. In this study, a draft genome of a bacterium from candidate phylum SBR1093 was reconstructed with the metagenome of an industrial activated sludge. Based on comparative genomics, this autotrophy may occur via a newly discovered carbon fixation path, the hydroxypropionate-hydroxybutyrate (HPHB cycle, which was demonstrated in a previous work to be uniquely possessed by some genera from Archaea. This bacterium possesses all of the thirteen enzymes required for the HPHB cycle; these enzymes share 30∼50% identity with those in the autotrophic species of Archaea that undergo the HPHB cycle and 30∼80% identity with the corresponding enzymes of the mixotrophic species within Bradyrhizobiaceae. Thus, this bacterium might have an autotrophic growth mode in certain conditions. A phylogenetic analysis based on the 16S rRNA gene reveals that the phylotypes within candidate phylum SBR1093 are primarily clustered into 5 clades with a shallow branching pattern. This bacterium is clustered with phylotypes from organically contaminated environments, implying a demand for organics in heterotrophic metabolism. Considering the types of regulators, such as FnR, Fur, and ArsR, this bacterium might be a facultative aerobic mixotroph with potential multi-antibiotic and heavy metal resistances. This is the first report on Bacteria that may perform potential carbon fixation via the HPHB cycle, thus may expand our knowledge of the distribution and importance of the HPHB cycle in the biosphere.

  18. Inhibitory effect of self-generated extracellular dissolved organic carbon on carbon dioxide fixation in sulfur-oxidizing bacteria during a chemoautotrophic cultivation process and its elimination.

    Science.gov (United States)

    Wang, Ya-Nan; Tsang, Yiu Fai; Wang, Lei; Fu, Xiaohua; Hu, Jiajun; Li, Huan; Le, Yiquan

    2018-03-01

    The features of extracellular dissolved organic carbon (EDOC) generation in two typical aerobic sulfur-oxidizing bacteria (Thiobacillus thioparus DSM 505 and Halothiobacillus neapolitanus DSM 15147) and its impact on CO 2 fixation during chemoautotrophic cultivation process were investigated. The results showed that EDOC accumulated in both strains during CO 2 fixation process. Large molecular weight (MW) EDOC derived from cell lysis and decay was dominant during the entire process in DSM 505, whereas small MW EDOC accounted for a large proportion during initial and middle stages of DSM 15147 as its cytoskeleton synthesis rate did not keep up with CO 2 assimilation rate. The self-generated EDOC feedback repressed cbb gene transcription and thus decreased total bacterial cell number and CO 2 fixation yield in both strains, but DSM 505 was more sensitive to this inhibition effect. Moreover, the membrane bioreactor effectively decreased the EDOC/TOC ratio and improved carbon fixation yield of DSM 505. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Promoting helix pitch and trichome length to improve biomass harvesting efficiency and carbon dioxide fixation rate by Spirulina sp. in 660 m2 raceway ponds under purified carbon dioxide from a coal chemical flue gas.

    Science.gov (United States)

    Cheng, Jun; Guo, Wangbiao; Ameer Ali, Kubar; Ye, Qing; Jin, Guiyong; Qiao, Zhanshan

    2018-08-01

    The helix pitch and trichome length of Spirulina sp. were promoted to improve the biomass harvesting efficiency and CO 2 fixation rate in 660 m 2 raceway ponds aerated with food-grade CO 2 purified from a coal chemical flue gas. The CO 2 fixation rate was improved with increased trichome length of the Spirulina sp. in a raceway pond with double paddlewheels, baffles, and CO 2 aerators (DBA raceway pond). The trichome length has increased by 33.3 μm, and CO 2 fixation rate has increased by 42.3% and peaked to 51.3 g/m 2 /d in a DBA raceway pond. Biomass harvesting efficiency was increased with increased helix pitch. When the day-average greenhouse temperature was 33 °C and day-average sunlight intensity was 72,100 lu×, the helix pitch of Spirulina sp. was increased to 56.2 μm. Hence the biomass harvesting efficiency was maximized to 75.6% and biomass actual yield was increased to 35.9 kg in a DBA raceway pond. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. FY 1996 annual report of investigation on biological fixation of carbon dioxide. 2; 1996 nendo seibutsuteki CO2 kotei ni kansuru chosa hokokusho. 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    Various kinds of biological fixation processes of CO2 were evaluated from the various viewpoints. Afforestation of tropical and temperate areas, greening of desert, biomass energy production in these areas by energy plantation, coastal mangrove plantation, fertilization with nitrogen and phosphate to outer ocean and coastal, upwelling zone fertilization with iron, and coral reef expansion combined with OTEC (ocean thermal energy conversion) were comparatively investigated as the selected measures. As a result, the cost of CO2 fixation by cultivation of sea weed and plankton was much higher than that of afforestation. The iron fertilization method which was considered to be one of the high CO2 reduction potentials might be economical. However, its effect could not be quantitatively evaluated. The afforestation of tropical and temperate areas seemed to be most feasible in a short term from the viewpoints of economy and environment. It was suggested that the establishment of a systematic water management technology could make greening and afforestation of desert. 76 refs., 27 figs., 28 tabs.

  1. Nano-sized titanium dioxide-induced splenic toxicity: A biological pathway explored using microarray technology

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Lei [Medical College of Soochow University, Suzhou 215123 (China); Wang, Ling [Library of Soochow University, Suzhou 215123 (China); Sang, Xuezi; Zhao, Xiaoyang; Hong, Jie; Cheng, Shen; Yu, Xiaohong; Liu, Dong; Xu, Bingqing; Hu, Renping; Sun, Qingqing; Cheng, Jie; Cheng, Zhe; Gui, Suxin [Medical College of Soochow University, Suzhou 215123 (China); Hong, Fashui, E-mail: Hongfsh_cn@sina.com [Medical College of Soochow University, Suzhou 215123 (China)

    2014-08-15

    Highlights: • Exposure to TiO{sub 2} NPs could be accumulated in the spleen. • Exposure to TiO{sub 2} NPs caused spleen lesions in mice. • Exposure to TiO{sub 2} NPs resulted in immune dysfunction in mice. • Exposure to TiO{sub 2} NPs caused alteration of 1041 genes expression of known function in the spleen. - Abstract: Titanium dioxide nanoparticles (TiO{sub 2} NPs) have been widely used in various areas, and its potential toxicity has gained wide attention. However, the molecular mechanisms of multiple genes working together in the TiO{sub 2} NP-induced splenic injury are not well understood. In the present study, 2.5, 5, or 10 mg/kg body weight TiO{sub 2} NPs were administered to the mice by intragastric administration for 90 consecutive days, their immune capacity in the spleen as well as the gene-expressed characteristics in the mouse damaged spleen were investigated using microarray assay. The findings showed that with increased dose, TiO{sub 2} NP exposure resulted in the increases of spleen indices, immune dysfunction, and severe macrophage infiltration as well as apoptosis in the spleen. Importantly, microarray data showed significant alterations in the expressions of 1041 genes involved in immune/inflammatory responses, apoptosis, oxidative stress, stress responses, metabolic processes, ion transport, signal transduction, cell proliferation/division, cytoskeleton and translation in the 10 mg/kg TiO{sub 2} NP-exposed spleen. Specifically, Cyp2e1, Sod3, Mt1, Mt2, Atf4, Chac1, H2-k1, Cxcl13, Ccl24, Cd14, Lbp, Cd80, Cd86, Cd28, Il7r, Il12a, Cfd, and Fcnb may be potential biomarkers of spleen toxicity following exposure to TiO{sub 2} NPs.

  2. Use of chemically treated carbon dioxide. ; Separation, recovery and fixation of carbon dioxide from large scale origination. Nisanka tanso no kagaku teki shori riyo; Nisanka tanso no daikibo hasseigen kara no bunri kaishu to koteika

    Energy Technology Data Exchange (ETDEWEB)

    Saito, M. (National Research Inst. for Pollution and Resources, Tsukuba (Japan))

    1991-02-15

    Tehcnology for separation, recovery and fixation of CO {sub 2} was stated. In an absorption method used as a separating recovery method, CO {sub 2} in the waste gas is absorbed into a solution such as amine, heated and recovered. In an adsorption method, the CO {sub 2} is adsorbed by adsorbent such as zeolite, and recovered either by reduction of pressure or by heating. In a distillation method, the CO {sub 2} is distilled under low temperature and high pressure. In a membrane separation method, the difference of the membrane transmisison speed is used. In a fixation technology, the CO {sub 2} disposed into the ocean is liquefied by compression and forced into the deep sea through pipings. The liquid CO {sub 2} has greater density than water under 200 to 300 atmospheric pressure and clathrate is produced over the interface between the sea water and the liquid CO {sub 2} but the influence on the environment should be evaluated. As a means of recycling, synthesis of methanol or hydrocarbon with hydrogen contacting can be considered, and if such synthesis is used, fossil fuel can be reduced. As the source of the hydrogen, a method for combining the electrolysis of water and energy such as the sun and hydraulic power which do not generate CO {sub 2}. 16 refs., 3 figs.

  3. C1 Metabolism in Corynebacterium glutamicum: an Endogenous Pathway for Oxidation of Methanol to Carbon Dioxide

    Science.gov (United States)

    Witthoff, Sabrina; Mühlroth, Alice

    2013-01-01

    Methanol is considered an interesting carbon source in “bio-based” microbial production processes. Since Corynebacterium glutamicum is an important host in industrial biotechnology, in particular for amino acid production, we performed studies of the response of this organism to methanol. The C. glutamicum wild type was able to convert 13C-labeled methanol to 13CO2. Analysis of global gene expression in the presence of methanol revealed several genes of ethanol catabolism to be upregulated, indicating that some of the corresponding enzymes are involved in methanol oxidation. Indeed, a mutant lacking the alcohol dehydrogenase gene adhA showed a 62% reduced methanol consumption rate, indicating that AdhA is mainly responsible for methanol oxidation to formaldehyde. Further studies revealed that oxidation of formaldehyde to formate is catalyzed predominantly by two enzymes, the acetaldehyde dehydrogenase Ald and the mycothiol-dependent formaldehyde dehydrogenase AdhE. The Δald ΔadhE and Δald ΔmshC deletion mutants were severely impaired in their ability to oxidize formaldehyde, but residual methanol oxidation to CO2 was still possible. The oxidation of formate to CO2 is catalyzed by the formate dehydrogenase FdhF, recently identified by us. Similar to the case with ethanol, methanol catabolism is subject to carbon catabolite repression in the presence of glucose and is dependent on the transcriptional regulator RamA, which was previously shown to be essential for expression of adhA and ald. In conclusion, we were able to show that C. glutamicum possesses an endogenous pathway for methanol oxidation to CO2 and to identify the enzymes and a transcriptional regulator involved in this pathway. PMID:24014532

  4. Titanium dioxide nanoparticles stimulate sea urchin immune cell phagocytic activity involving TLR/p38 MAPK-mediated signalling pathway

    Science.gov (United States)

    Pinsino, Annalisa; Russo, Roberta; Bonaventura, Rosa; Brunelli, Andrea; Marcomini, Antonio; Matranga, Valeria

    2015-01-01

    Titanium dioxide nanoparticles (TiO2NPs) are one of the most widespread-engineered particles in use for drug delivery, cosmetics, and electronics. However, TiO2NP safety is still an open issue, even for ethical reasons. In this work, we investigated the sea urchin Paracentrotus lividus immune cell model as a proxy to humans, to elucidate a potential pathway that can be involved in the persistent TiO2NP-immune cell interaction in vivo. Morphology, phagocytic ability, changes in activation/inactivation of a few mitogen-activated protein kinases (p38 MAPK, ERK), variations of other key proteins triggering immune response (Toll-like receptor 4-like, Heat shock protein 70, Interleukin-6) and modifications in the expression of related immune response genes were investigated. Our findings indicate that TiO2NPs influence the signal transduction downstream targets of p38 MAPK without eliciting an inflammatory response or other harmful effects on biological functions. We strongly recommend sea urchin immune cells as a new powerful model for nano-safety/nano-toxicity investigations without the ethical normative issue. PMID:26412401

  5. Endogenous sulfur dioxide regulates hippocampal neuron apoptosis in developing epileptic rats and is associated with the PERK signaling pathway.

    Science.gov (United States)

    Niu, Manman; Han, Ying; Li, Qinrui; Zhang, Jing

    2018-02-05

    Epilepsy is among the most common neurological diseases in children. Recurrent seizures can result in hippocampal damage and seriously impair learning and memory functions in children. However, the mechanisms underlying epilepsy-related brain injury are unclear. Neuronal apoptosis is among the most common neuropathological manifestations of brain injury. Endogenous sulfur dioxide (SO 2 ) has been shown to be involved in seizures and related neuron apoptosis. However, the role of endogenous SO 2 in epilepsy remains unclear. This study assessed whether endogenous SO 2 is involved in epilepsy and its underlying mechanisms. Using a rat epilepsy model induced by an intraperitoneal injection of kainic acid (KA), we found that hippocampal neuron apoptosis was induced in epileptic rats, and the SO 2 content and aspartate aminotransferase (AAT) activity in the plasma were increased compared to those in the control group. However, the inhibition of SO 2 production by l-aspartate-β-hydroxamate (HDX) can subvert this response 72h after an epileptic seizure. No difference in apoptosis was observed 7 d after the epileptic seizure in the KA and KA+HDX groups. The protein expression levels of AAT2, glucose-regulated protein 78 (GRP78), pancreatic eIF2 kinase-like ER kinase (PERK) and phospho-PERK (p-PERK) were remarkably elevated in the hippocampi of the epileptic rats, while the HDX treatment was capable of reversing this process 7 d after the epileptic seizure. These results indicate that the inhibition of endogenous SO 2 production can alleviate neuronal apoptosis and is associated with the PERK signaling pathway during the initial stages after epileptic seizure, but inhibiting SO 2 production only delayed the occurrence of apoptosis and did not prevent neuronal apoptosis in the epileptic rats. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Proteome Profiling of BEAS-2B Cells Treated with Titanium Dioxide Reveals Potential Toxicity of and Detoxification Pathways for Nanomaterial

    Science.gov (United States)

    Oxidative stress is known to play important roles in nanomaterial-induced toxicities. However, the proteins and signaling pathways associated with nanomaterial-mediated oxidative stress and toxicity are largely unknown. To identify oxidative stress-responding toxicity pathways an...

  7. Proteome Profiling Reveals Potential Toxicity and Detoxification Pathways Following Exposure of BEAS-2B Cells to Engineered Nanoparticle Titanium Dioxide

    Science.gov (United States)

    Identification of toxicity pathways linked to chemical -exposure is critical for a better understanding of biological effects of the exposure, toxic mechanisms, and for enhancement of the prediction of chemical toxicity and adverse health outcomes. To identify toxicity pathways a...

  8. Fixation and utilization of CO2 by biological and/or chemical processes

    International Nuclear Information System (INIS)

    Hiromichi, N.

    1994-01-01

    This paper presents the carbon dioxide fixation and utilisation by biological and/or chemical processes. It presents research objectives and program contents for the effective fixation of carbon dioxide by micro-organism and its hydrogenation. (TEC). 5 figs., 2 tabs

  9. Carbon dioxide fixation by artificial photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Ibusuki, Takashi; Koike, Kazuhide; Ishitani, Osamu [National Inst. for Resources and Environment, AIST, MITI, Tsukuba, Ibaraki (Japan)

    1993-12-31

    Green plants can absorb atmospheric CO{sub 2} and transform it to sugars, carbohydrates through their photosynthetic systems, but they become the source of CO{sub 2} when they are dead. This is the reason why artificial leaves which can be alive forever should be developed to meet with global warming due to the increase of CO{sub 2} concentration. The goal of artificial photosynthesis is not to construct the same system as the photosynthetic one, but to mimic the ability of green plants to utilize solar energy to make high energy chemicals. Needless to say, the artificial photosynthetic system is desired to be as simple as possible and to be as efficient as possible. From the knowledge on photosynthesis and the results of previous investigations, the critical components of artificial photosynthetic system are understood as follows: (1) light harvesting chromophore, (2) a center for electron transfer and charge separation, (3) catalytic sites for converting small molecules like water and CO{sub 2} (mutilelectron reactions) which are schematically described.

  10. Report on a survey in fiscal 1999. Survey on trends in new carbon dioxide fixation technologies utilizing bacteria and algae. (3); 1999 nendo saikin sorui wo riyoshita atarashii nisanka tanso kotei gijutsu no doko chosa. 3

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    In order to achieve collection and effective utilization of CO2 as the representative greenhouse effect gas, through use of microorganism functions, a survey was performed on problems when the CO2 fixation system is applied to factories, based on the results of surveys in fiscals 1997 and 1998 and the supplementary surveys therein. Discussions were given on feasibility and effect of introducing the in situ CO2 fixation systems. With regard to the current status and problems in technologies to fix and utilize effectively CO2 by use of photosynthetic bacteria and micro algae by means of solar beam, the paper summarizes the 'searches and breeding of bacteria and algae' and the 'research and development of a high-density and large-quantity cultivation system such as for CO2 fixation and useful substance production'. The paper also describes problems in the CO2 fixation technologies utilizing bacteria and algae. With regard to the CO2 fixation technologies utilizing bacteria and algae, the paper summarized the contents of the survey on CO2 fixation by using photosynthetic bacteria, clostridium bacteria, and coryne bacteria. Surveys were performed inside and outside the country on kinds and existence quantities of unutilized organic wastes in which microorganisms that fix CO2 can be utilized. The CO2 fixation systems can be considered of their possibilities of being introduced into foodstuff factories where organic waste water with high concentration can be obtained. (NEDO)

  11. Report on a survey in fiscal 1999. Survey on trends in new carbon dioxide fixation technologies utilizing bacteria and algae. (3); 1999 nendo saikin sorui wo riyoshita atarashii nisanka tanso kotei gijutsu no doko chosa. 3

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    In order to achieve collection and effective utilization of CO2 as the representative greenhouse effect gas, through use of microorganism functions, a survey was performed on problems when the CO2 fixation system is applied to factories, based on the results of surveys in fiscals 1997 and 1998 and the supplementary surveys therein. Discussions were given on feasibility and effect of introducing the in situ CO2 fixation systems. With regard to the current status and problems in technologies to fix and utilize effectively CO2 by use of photosynthetic bacteria and micro algae by means of solar beam, the paper summarizes the 'searches and breeding of bacteria and algae' and the 'research and development of a high-density and large-quantity cultivation system such as for CO2 fixation and useful substance production'. The paper also describes problems in the CO2 fixation technologies utilizing bacteria and algae. With regard to the CO2 fixation technologies utilizing bacteria and algae, the paper summarized the contents of the survey on CO2 fixation by using photosynthetic bacteria, clostridium bacteria, and coryne bacteria. Surveys were performed inside and outside the country on kinds and existence quantities of unutilized organic wastes in which microorganisms that fix CO2 can be utilized. The CO2 fixation systems can be considered of their possibilities of being introduced into foodstuff factories where organic waste water with high concentration can be obtained. (NEDO)

  12. Proteome Profiling Reveals Potential Toxicity and Detoxification Pathways Following Exposure of BEAS-2B Cells to Engineered Titanium Dioxide Nanoparticles

    Science.gov (United States)

    Oxidative stress is known to play important roles in engineered nanomaterial induced cellular toxicity. However, the proteins and signaling pathways associated with the engineered nanomaterial mediated oxidative stress and toxicity are largely unknown. To identify these toxicity ...

  13. 14CO2 fixation pattern of cyanobacteria

    International Nuclear Information System (INIS)

    Erdmann, N.; Schiewer, U.

    1985-01-01

    The 14 CO 2 fixation pattern of three cyanobacteria in the light and dark were studied. Two different chromatographic methods widely used for separating labelled photosynthetic intermediates were compared. After ethanolic extraction, a rather uniform fixation pattern reflecting mainly the β-carboxylation pathway is obtained for all 3 species. Of the intermediates, glucosylglycerol is specific and high citrulline and low malate contents are fairly specific to cyanobacteria. The composition of the 14 CO 2 fixation pattern is hardly affected by changes in temperature or light intensity, but it is severely affected by changes in the water potential of the medium. (author)

  14. CSF coccidioides complement fixation

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003526.htm CSF coccidioides complement fixation test To use the sharing features on this page, please enable JavaScript. CSF coccidioides complement fixation is a test that checks ...

  15. Intrascleral IOL Fixation.

    Science.gov (United States)

    Jacob, Soosan

    2017-01-01

    Intrascleral sutureless intraocular lens (IOL) fixation utilizes direct haptic fixation within the sclera in eyes with deficient capsular support. This has advantages of long-term stability, good control of tilt and decentration, and lesser pseudophakodonesis. This review summarizes various techniques for intrascleral haptic fixation, results, complications, adaptations in special situations, modifications of the technique, combination surgeries, and intrascleral capsular bag fixation techniques (glued capsular hook). Copyright 2017 Asia-Pacific Academy of Ophthalmology.

  16. Effects of titanium dioxide nanoparticles isolated from confectionery products on the metabolic stress pathway in human lung fibroblast cells.

    Science.gov (United States)

    Periasamy, Vaiyapuri Subbarayan; Athinarayanan, Jegan; Al-Hadi, Ahmed M; Juhaimi, Fahad Al; Alshatwi, Ali A

    2015-04-01

    Titanium dioxide (TiO2) is a common additive in many foods, pigments, personal care products, and other consumer products used in daily life. Despite the widespread use of nanoscale TiO2 and composites of nanoscale TiO2 in the food industry, there is a serious lack of awareness of the toxicity of TiO2 nanoparticles (NPs) among consumers and manufacturers. There is an urgent need for toxicological studies of TiO2 NPs. TiO2 food additives separated from marketed foods were characterized by transmission electron microscopy. In addition, the effects of TiO2 NPs on metabolic stress in WI-38 cells were analyzed. Cell viability, total ROS, mitochondrial transmembrane potential (ΔψM), cell cycle, and metabolism-related gene expression were analyzed. The results indicate that TiO2 NPs have a significant concentration-dependent toxic effect in lung cells. The ΔψM, the intracellular ROS level, and the stages of the WI-38 cell cycle were altered by increasing TiO2 concentrations after exposure for 24 and 48 h relative to the control. Cytochrome P450 1A, GSTM3, and glutathione S-transferase A4 upregulation in response to the TiO2 NPs was observed. These findings suggest that the toxicity of TiO2 from confectionery products in WI-38 cells may be mediated through an increase in oxidative stress. The results of this study clearly demonstrate the nanotoxicological effects of TiO2 on WI-38 cells and will be useful for nanotoxicological indexing.

  17. Oxidation of fluoroquinolone antibiotics and structurally related amines by chlorine dioxide: Reaction kinetics, product and pathway evaluation.

    Science.gov (United States)

    Wang, Pei; He, Yi-Liang; Huang, Ching-Hua

    2010-12-01

    Fluoroquinolones (FQs) are a group of widely prescribed antibiotics and have been frequently detected in the aquatic environment. The reaction kinetics and transformation of seven FQs (ciprofloxacin (CIP), enrofloxacin (ENR), norfloxacin (NOR), ofloxacin (OFL), lomefloxacin (LOM), pipemidic acid (PIP) and flumequine (FLU)) and three structurally related amines (1-phenylpiperazine (PP), N-phenylmorpholine (PM) and 4-phenylpiperidine (PD)) toward chlorine dioxide (ClO(2)) were investigated to elucidate the behavior of FQs during ClO(2) disinfection processes. The reaction kinetics are highly pH-dependent, can be well described by a second-order kinetic model incorporating speciation of FQs, and follow the trend of OFL > ENR > CIP ∼ NOR ∼ LOM > > PIP in reactivity. Comparison among FQs and related amines and product characterization indicate that FQs' piperazine ring is the primary reactive center toward ClO(2). ClO(2) likely attacks FQ's piperazinyl N4 atom followed by concerted fragmentation involving piperazinyl N1 atom, leading to dealkylation, hydroxylation and intramolecular ring closure at the piperazine moiety. While FQs with tertiary N4 react faster with ClO(2) than FQs with secondary N4, the overall reactivity of the piperazine moiety also depends strongly on the quinolone ring through electronic effects. The reaction rate constants obtained in clean water matrix can be used to model the decay of CIP by ClO(2) in surface water samples, but overestimate the decay in wastewater samples. Overall, transformation of FQs, particularly for those with tertiary N4 amines, could be expected under typical ClO(2) disinfection conditions. However, the transformation may not eliminate antibacterial activity because of little destruction at the quinolone ring. Copyright © 2010 Elsevier Ltd. All rights reserved.

  18. Investigation of the chemical pathway of gaseous nitrogen dioxide formation during flue gas desulfurization with dry sodium bicarbonate injection

    Science.gov (United States)

    Stein, Antoinette Weil

    The chemical reaction pathway for the viable flue gas desulfurization process, dry sodium bicarbonate injection, was investigated to mitigate undesirable plume discoloration. Based on a foundation of past findings, a simplified three-step reaction pathway was hypothesized for the formation of the plume-discoloring constituent, NO2. As the first step, it was hypothesized that sodium sulfite formed by sodium bicarbonate reaction with flue gas SO 2. As the second step, it was hypothesized that sodium nitrate formed by sodium sulfite reaction with flue gas NO. And as the third step, it was hypothesized that NO2 and sodium sulfate formed by sodium nitrate reaction with SO2. The second and third hypothesized steps were experimentally investigated using an isothermal fixed bed reactor. As reported in the past, technical grade sodium sulfite was found to be un-reactive with NO and O2. Freshly prepared sodium sulfite, maintained unexposed to moist air, was shown to react with NO and O2 resulting in a mixture of sodium nitrite and sodium nitrate together with a significant temperature rise. This reaction was found to proceed only when oxygen was present in the flue gas. As reported in the past, technical grade sodium nitrate was shown to be un-reactive with SO2. But freshly formed sodium nitrate kept unexposed to humidity was found to be reactive with SO2 and O 2 resulting in the formation of NO2 and sodium sulfate polymorphic Form I. The NO2 formation by this reaction was shown to be temperature dependent with maximum formation at 175°C. Plume mitigation methods were studied based on the validated three-step reaction pathway. Mitigation of NO2 was exhibited by limiting oxygen concentration in the flue gas to a level below 5%. It was also shown that significant NO2 mitigation was achieved by operating below 110°C or above 250°C. An innovative NO2 mitigation method was patented as a result of the findings of this study. The patented process incorporated a process step of

  19. Adsorption and Photocatalytic Decomposition of the β-Blocker Metoprolol in Aqueous Titanium Dioxide Suspensions: Kinetics, Intermediates, and Degradation Pathways

    Directory of Open Access Journals (Sweden)

    Violette Romero

    2013-01-01

    Full Text Available This study reports the photocatalytic degradation of the β-blocker metoprolol (MET using TiO2 suspended as catalyst. A series of photoexperiments were carried out by a UV lamp, emitting in the 250–400 nm range, providing information about the absorption of radiation in the photoreactor wall. The influence of the radiation wavelength on the MET photooxidation rate was investigated using a filter cutting out wavelengths shorter than 280 nm. Effects of photolysis and adsorption at different initial pH were studied to evaluate noncatalytic degradation for this pharmaceutical. MET adsorption onto titania was fitted to two-parameter Langmuir isotherm. From adsorption results it appears that the photocatalytic degradation can occur mainly on the surface of TiO2. MET removed by photocatalysis was 100% conditions within 300 min, while only 26% was achieved by photolysis at the same time. TiO2 photocatalysis degradation of MET in the first stage of the reaction followed approximately a pseudo-first-order model. The major reaction intermediates were identified by LC/MS analysis such as 3-(propan-2-ylaminopropane-1,2-diol or 3-aminoprop-1-en-2-ol. Based on the identified intermediates, a photocatalytic degradation pathway was proposed, including the cleavage of side chain and the hydroxylation addition to the parent compounds.

  20. Application of microbial photosynthesis to energy production and CO2 fixation

    International Nuclear Information System (INIS)

    Asada, Y.; Miyake, J.

    1994-01-01

    This paper presents different applications of microbial photosynthesis for energy production and carbon dioxide fixation. The authors discuss about energetic aspects of photosynthesis and features of biological way for solar energy conversion. (TEC). 4 figs., 12 refs

  1. Pathways of primary CO2 fixation in C-4 plants of the family chenopodiaceae from the arid zone of central Asia

    International Nuclear Information System (INIS)

    P'yankov, V.I.; Vakhrusheva, D.V.

    1991-01-01

    The authors determined the kinetics of 14 C incorporation after a 10-sec gulp of 14 CO 2 to study formation of primary photosynthetic products in 35 C-4 species of the family chenopodiaceae in the desert zone of central Asia. Representatives of the main life forms of desert plants with various types of anatomical structure of the assimilating organs (salsoloid, kochioid, atriplercoid, and suaedoid groups) were among the studied species. It was demonstrated that the ratio of pathways of formation of C-4 acids (malate and aspartate) depends upon the structural type affiliation and the ecological conditions of the habitat. Plants of the suaedoid and atriplecoid groups (which usually dwell under conditions of salination) exhibit the aspartate NAD-malic enzyme (NAD-ME) type of C-4 photosynthesis. The malate and aspartate types of metabolism are detected in species of the kochioid group. All biochemical variants (NADP-ME, NAD-ME, and mixed) are represented in the salsoloid group. Psammophilous species of this group have the malate type of acid metabolism, whereas halophilic species have the aspartate type. Quantitative criteria are proposed for referring C-4 plants to the NAD- and NADP-ME types on the basis of formation of primary products. It is demonstrated that the role of the aspartate pathway of CO 2 transfer in plants increases in proportion to worsening of ecological conditions of the habitat. The evolutionary sequence of metabolic systems was formed in the C-3-NAD-ME-NADP-ME direction, the origin of the C-4 syndrome having been associated with colonization of arid territories, especially saline localities

  2. Biological conversion of carbon dioxide and hydrogen into liquid fuels and industrial chemicals.

    Science.gov (United States)

    Hawkins, Aaron S; McTernan, Patrick M; Lian, Hong; Kelly, Robert M; Adams, Michael W W

    2013-06-01

    Non-photosynthetic routes for biological fixation of carbon dioxide into valuable industrial chemical precursors and fuels are moving from concept to reality. The development of 'electrofuel'-producing microorganisms leverages techniques in synthetic biology, genetic and metabolic engineering, as well as systems-level multi-omic analysis, directed evolution, and in silico modeling. Electrofuel processes are being developed for a range of microorganisms and energy sources (e.g. hydrogen, formate, electricity) to produce a variety of target molecules (e.g. alcohols, terpenes, alkenes). This review examines the current landscape of electrofuel projects with a focus on hydrogen-utilizing organisms covering the biochemistry of hydrogenases and carbonic anhydrases, kinetic and energetic analyses of the known carbon fixation pathways, and the state of genetic systems for current and prospective electrofuel-producing microorganisms. Copyright © 2013 Elsevier Ltd. All rights reserved.

  3. Guide to radiation fixatives

    International Nuclear Information System (INIS)

    Tawil, J.J.; Bold, F.C.

    1983-11-01

    This report identifies and then characterizes a variety of substances available in the market place for potential effectiveness as a fixative on radiologically contaminated surfaces. The substances include both generic chemicals and proprietary products. In selecting a fixative for a particular application, several attributes of the fixative may be relevant to the choice. These attributes include: toxicity, durability, and cleanliness and removability. In addition to the attributes of the fixative, one should also take into account certain characteristics of the site to be treated. These characteristics relate to climate, nature of the surface, use to which the treated surface will be put, subsequent cleanup operations, and type of neighboring surfaces. Finally, costs and potential environmental effects may influence the decision. A variety of fixatives are evaluated with respect to these various attributes and summarized in a reference table

  4. Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

    Energy Technology Data Exchange (ETDEWEB)

    Wang, A-nan [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Graduate School of Chinese Academy of Sciences, Beijing 100039 (China); Teng, Ying [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Hu, Xue-feng [Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Wu, Long-hua; Huang, Yu-juan [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Luo, Yong-ming, E-mail: ymluo@yic.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003 (China); Christie, Peter [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)

    2016-01-15

    Diphenylarsinic acid (DPAA) is formed during the leakage of arsenic chemical weapons in sites and poses a high risk to biota. However, remediation methods for DPAA contaminated soils are rare. Here, the photocatalytic oxidation (PCO) process by nano-sized titanium dioxide (TiO{sub 2}) was applied to degrade DPAA in soil. The degradation pathway was firstly studied, and arsenate was identified as the final product. Then, an orthogonal array experimental design of L{sub 9}(3){sup 4}, only 9 experiments were needed, instead of 81 experiments in a conventional one-factor-at-a-time, was used to optimize the operational parameters soil:water ratio, TiO{sub 2} dosage, irradiation time and light intensity to increase DPAA removal efficiency. Soil:water ratio was found to have a more significant effect on DPAA removal efficiency than other properties. The optimum conditions to treat 4 g soil with a DPAA concentration of 20 mg kg{sup −1} were found to be a 1:10 soil: water ratio, 40 mW cm{sup −2} light intensity, 5% TiO{sub 2} in soil, and a 3-hour irradiation time, with a removal efficiency of up to 82.7%. Furthermore, this method (except for a change in irradiation time from 3 to 1.5 h) was validated in nine different soils and the removal efficiencies ranged from 57.0 to 78.6%. Removal efficiencies were found to be negatively correlated with soil electrical conductivity, organic matter content, pH and total phosphorus content. Finally, coupled with electron spin resonance (ESR) measurement, these soil properties affected the generation of OH• by TiO{sub 2} in soil slurry. This study suggests that TiO{sub 2} photocatalytic oxidation is a promising treatment for removing DPAA from soil. - Highlights: • DPAA was degraded into arsenate through TiO{sub 2} (P25) photocatalytic oxidation. • Soil/water ratio was more influential on the removal of DPAA in soil by TiO{sub 2} (P25). • Soil properties affected the adsorption of DPAA and the generation of OH• by Ti

  5. Diphenylarsinic acid contaminated soil remediation by titanium dioxide (P25) photocatalysis: Degradation pathway, optimization of operating parameters and effects of soil properties

    International Nuclear Information System (INIS)

    Wang, A-nan; Teng, Ying; Hu, Xue-feng; Wu, Long-hua; Huang, Yu-juan; Luo, Yong-ming; Christie, Peter

    2016-01-01

    Diphenylarsinic acid (DPAA) is formed during the leakage of arsenic chemical weapons in sites and poses a high risk to biota. However, remediation methods for DPAA contaminated soils are rare. Here, the photocatalytic oxidation (PCO) process by nano-sized titanium dioxide (TiO_2) was applied to degrade DPAA in soil. The degradation pathway was firstly studied, and arsenate was identified as the final product. Then, an orthogonal array experimental design of L_9(3)"4, only 9 experiments were needed, instead of 81 experiments in a conventional one-factor-at-a-time, was used to optimize the operational parameters soil:water ratio, TiO_2 dosage, irradiation time and light intensity to increase DPAA removal efficiency. Soil:water ratio was found to have a more significant effect on DPAA removal efficiency than other properties. The optimum conditions to treat 4 g soil with a DPAA concentration of 20 mg kg"−"1 were found to be a 1:10 soil: water ratio, 40 mW cm"−"2 light intensity, 5% TiO_2 in soil, and a 3-hour irradiation time, with a removal efficiency of up to 82.7%. Furthermore, this method (except for a change in irradiation time from 3 to 1.5 h) was validated in nine different soils and the removal efficiencies ranged from 57.0 to 78.6%. Removal efficiencies were found to be negatively correlated with soil electrical conductivity, organic matter content, pH and total phosphorus content. Finally, coupled with electron spin resonance (ESR) measurement, these soil properties affected the generation of OH• by TiO_2 in soil slurry. This study suggests that TiO_2 photocatalytic oxidation is a promising treatment for removing DPAA from soil. - Highlights: • DPAA was degraded into arsenate through TiO_2 (P25) photocatalytic oxidation. • Soil/water ratio was more influential on the removal of DPAA in soil by TiO_2 (P25). • Soil properties affected the adsorption of DPAA and the generation of OH• by TiO_2.

  6. The emergence and early evolution of biological carbon-fixation.

    Science.gov (United States)

    Braakman, Rogier; Smith, Eric

    2012-01-01

    The fixation of CO₂ into living matter sustains all life on Earth, and embeds the biosphere within geochemistry. The six known chemical pathways used by extant organisms for this function are recognized to have overlaps, but their evolution is incompletely understood. Here we reconstruct the complete early evolutionary history of biological carbon-fixation, relating all modern pathways to a single ancestral form. We find that innovations in carbon-fixation were the foundation for most major early divergences in the tree of life. These findings are based on a novel method that fully integrates metabolic and phylogenetic constraints. Comparing gene-profiles across the metabolic cores of deep-branching organisms and requiring that they are capable of synthesizing all their biomass components leads to the surprising conclusion that the most common form for deep-branching autotrophic carbon-fixation combines two disconnected sub-networks, each supplying carbon to distinct biomass components. One of these is a linear folate-based pathway of CO₂ reduction previously only recognized as a fixation route in the complete Wood-Ljungdahl pathway, but which more generally may exclude the final step of synthesizing acetyl-CoA. Using metabolic constraints we then reconstruct a "phylometabolic" tree with a high degree of parsimony that traces the evolution of complete carbon-fixation pathways, and has a clear structure down to the root. This tree requires few instances of lateral gene transfer or convergence, and instead suggests a simple evolutionary dynamic in which all divergences have primary environmental causes. Energy optimization and oxygen toxicity are the two strongest forces of selection. The root of this tree combines the reductive citric acid cycle and the Wood-Ljungdahl pathway into a single connected network. This linked network lacks the selective optimization of modern fixation pathways but its redundancy leads to a more robust topology, making it more

  7. The emergence and early evolution of biological carbon-fixation.

    Directory of Open Access Journals (Sweden)

    Rogier Braakman

    Full Text Available The fixation of CO₂ into living matter sustains all life on Earth, and embeds the biosphere within geochemistry. The six known chemical pathways used by extant organisms for this function are recognized to have overlaps, but their evolution is incompletely understood. Here we reconstruct the complete early evolutionary history of biological carbon-fixation, relating all modern pathways to a single ancestral form. We find that innovations in carbon-fixation were the foundation for most major early divergences in the tree of life. These findings are based on a novel method that fully integrates metabolic and phylogenetic constraints. Comparing gene-profiles across the metabolic cores of deep-branching organisms and requiring that they are capable of synthesizing all their biomass components leads to the surprising conclusion that the most common form for deep-branching autotrophic carbon-fixation combines two disconnected sub-networks, each supplying carbon to distinct biomass components. One of these is a linear folate-based pathway of CO₂ reduction previously only recognized as a fixation route in the complete Wood-Ljungdahl pathway, but which more generally may exclude the final step of synthesizing acetyl-CoA. Using metabolic constraints we then reconstruct a "phylometabolic" tree with a high degree of parsimony that traces the evolution of complete carbon-fixation pathways, and has a clear structure down to the root. This tree requires few instances of lateral gene transfer or convergence, and instead suggests a simple evolutionary dynamic in which all divergences have primary environmental causes. Energy optimization and oxygen toxicity are the two strongest forces of selection. The root of this tree combines the reductive citric acid cycle and the Wood-Ljungdahl pathway into a single connected network. This linked network lacks the selective optimization of modern fixation pathways but its redundancy leads to a more robust topology

  8. Fiscal 1994 report on results of R and D on innovative technology for producing advanced biomaterial. Technology of fixation and utilization of carbon dioxide using peptides; 1994 nendo senshin bio zairyo no sosei kako gijutsu no kenkyu kaihatsu seika hokokusho. Pepuchido oyo nisanka tanso koteika yuko riyo gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    R and D of a material was conducted that has a function of fixation of carbon dioxide for example, by synthesizing non-natural amino acids required for the manifestation of the function, incorporating the amino acids into new bio-functional peptides to be synthesized, and fixing the peptides on a substrate. Activities were carried out in three areas, which were (1) innovative technologies for producing functional molecules: R and D concerning structural and functional design of peptides, conformational control technique, preparation of peptides with photoelectric conversion function, peptide synthesis using enzyme, and method of incorporating non-natural amino acids into peptides, (2) R and D on materialization technologies of functional molecules: formation of film onto a substrate, pattern forming technique, substrate modification technique, peptide binding reagent or linker, and development of technologies for creation of biomaterials having molecular recognition function and their stabilization. and (3) comprehensive investigation and adjustment (operation of information exchange conference and adjustment of the progress). In (2), an examination was made on the effect of polymerization on functions, for example, by fixing molecular recognition peptides in monomers and polymers on a catalyst support. (NEDO)

  9. Radionuclide fixation mechanisms in rocks

    International Nuclear Information System (INIS)

    Nakashima, S.

    1991-01-01

    In the safety evaluation of the radioactive waste disposal in geological environment, the mass balance equation for radionuclide migration is given. The sorption of radionuclides by geological formations is conventionally represented by the retardation of the radionuclides as compared with water movement. In order to quantify the sorption of radionuclides by rocks and sediments, the distribution ratio is used. In order to study quantitatively the long term behavior of waste radionuclides in geological environment, besides the distribution ratio concept in short term, slower radionuclide retention reaction involving mineral transformation should be considered. The development of microspectroscopic method for long term reaction path modeling, the behavior of iron during granite and water interaction, the reduction precipitation of radionuclides, radionuclide migration pathways, and the representative scheme of radionuclide migration and fixation in rocks are discussed. (K.I.)

  10. Fixation of carbon dioxide by macrocyclic lanthanide(III) complexes under neutral conditions producing self-assembled trimeric carbonato-bridged compounds with μ3-η2:η2:η2 bonding.

    Science.gov (United States)

    Bag, Pradip; Dutta, Supriya; Biswas, Papu; Maji, Swarup Kumar; Flörke, Ulrich; Nag, Kamalaksha

    2012-03-28

    A series of mononuclear lanthanide(III) complexes [Ln(LH(2))(H(2)O)(3)Cl](ClO(4))(2) (Ln = La, Nd, Sm, Eu, Gd, Tb, Lu) of the tetraiminodiphenolate macrocyclic ligand (LH(2)) in 95 : 5 (v/v) methanol-water solution fix atmospheric carbon dioxide to produce the carbonato-bridged trinuclear complexes [{Ln(LH(2))(H(2)O)Cl}(3)(μ(3)-CO(3))](ClO(4))(4)·nH(2)O. Under similar conditions, the mononuclear Y(III) complex forms the dimeric compound [{Y(LH(2))(H(2)O)Cl}(μ(2)-CO(3)){Y(LH(2))(H(2)O)(2)}](ClO(4))(3)·4H(2)O. These complexes have been characterized by their IR and NMR ((1)H, (13)C) spectra. The X-ray crystal structures have been determined for the trinuclear carbonato-bridged compounds of Nd(III), Gd(III) and Tb(III) and the dinuclear compound of Y(III). In all cases, each of the metal centers are 8-coordinate involving two imine nitrogens and two phenolate oxygens of the macrocyclic ligand (LH(2)) whose two other imines are protonated and intramolecularly hydrogen-bonded with the phenolate oxygens. The oxygen atoms of the carbonate anion in the trinuclear complexes are bonded to the metal ions in tris-bidentate μ(3)-η(2):η(2):η(2) fashion, while they are in bis-bidentate μ(2)-η(2):η(2) mode in the Y(III) complex. The magnetic properties of the Gd(III) complex have been studied over the temperature range 2 to 300 K and the magnetic susceptibility data indicate a very weak antiferromagnetic exchange interaction (J = -0.042 cm(-1)) between the Gd(III) centers (S = 7/2) in the metal triangle through the carbonate bridge. The luminescence spectral behaviors of the complexes of Sm(III), Eu(III), and Tb(III) have been studied. The ligand LH(2) acts as a sensitizer for the metal ions in an acetonitrile-toluene glassy matrix (at 77 K) and luminescence intensities of the complexes decrease in the order Eu(3+) > Sm(3+) > Tb(3+).

  11. Flexible fixation and fracture healing

    DEFF Research Database (Denmark)

    Schmal, Hagen; Strohm, Peter C; Jaeger, Martin

    2011-01-01

    , noncomminuted fractures. External fixation uses external bars for stabilization, whereas internal fixation is realized by subcutaneous placement of locking plates. Both of these "biologic" osteosynthesis methods allow a minimally invasive approach and do not compromise fracture hematoma and periosteal blood...

  12. Sacroiliac Screw Fixation

    NARCIS (Netherlands)

    E.W. van den Bosch

    2003-01-01

    textabstractThe aim of this thesis is to evaluate three major aspects of the use of sacroiliac screws in patients with unstable pelvic ring fractures: the optimal technique for sacroiliac screw fixation, the reliability of peroperative fluoroscopy and the late results. We focused on the questions

  13. CO2 Fixation by Membrane Separated NaCl Electrolysis

    DEFF Research Database (Denmark)

    Park, Hyun Sic; Lee, Ju Sung; Han, Junyoung

    2015-01-01

    for converting CO2 into CaCO3 requires high temperature and high pressure as reaction conditions. This study proposes a method to fixate CaCO3 stably by using relatively less energy than existing methods. After forming NaOH absorbent solution through electrolysis of NaCl in seawater, CaCO3 was precipitated...... crystal product was high-purity calcite. The study shows a successful method for fixating CO2 by reducing carbon dioxide released into the atmosphere while forming high-purity CaCO3.......Atmospheric concentrations of carbon dioxide (CO2), a major cause of global warming, have been rising due to industrial development. Carbon capture and storage (CCS), which is regarded as the most effective way to reduce such atmospheric CO2 concentrations, has several environmental and technical...

  14. Microbial fixation of CO2 in water bodies and in drylands to combat climate change, soil loss and desertification.

    Science.gov (United States)

    Rossi, Federico; Olguín, Eugenia J; Diels, Ludo; De Philippis, Roberto

    2015-01-25

    The growing concern for the increase of the global warming effects due to anthropogenic activities raises the challenge of finding novel technological approaches to stabilize CO2 emissions in the atmosphere and counteract impinging interconnected issues such as desertification and loss of biodiversity. Biological-CO2 mitigation, triggered through biological fixation, is considered a promising and eco-sustainable method, mostly owing to its downstream benefits that can be exploited. Microorganisms such as cyanobacteria, green algae and some autotrophic bacteria could potentially fix CO2 more efficiently than higher plants, due to their faster growth. Some examples of the potential of biological-CO2 mitigation are reported and discussed in this paper. In arid and semiarid environments, soil carbon sequestration (CO2 fixation) by cyanobacteria and biological soil crusts is considered an eco-friendly and natural process to increase soil C content and a viable pathway to soil restoration after one disturbance event. Another way for biological-CO2 mitigation intensively studied in the last few years is related to the possibility to perform carbon dioxide sequestration using microalgae, obtaining at the same time bioproducts of industrial interest. Another possibility under study is the exploitation of specific chemotrophic bacteria, such as Ralstonia eutropha (or picketii) and related organisms, for CO2 fixation coupled with the production chemicals such as polyhydroxyalkanoates (PHAs). In spite of the potential of these processes, multiple factors still have to be optimized for maximum rate of CO2 fixation by these microorganisms. The optimization of culture conditions, including the optimal concentration of CO2 in the provided gas, the use of metabolic engineering and of dual purpose systems for the treatment of wastewater and production of biofuels and high value products within a biorefinery concept, the design of photobioreactors in the case of phototrophs are some

  15. Effect of the major components of industrial air pollution on nonsymbiotic nitrogen-fixation activity in soil

    Energy Technology Data Exchange (ETDEWEB)

    Islamov, S S; Chunderova, A I

    1976-01-01

    Industrial pollution of atmosphere inhibits the activity of non-symbiotic nitrogen fixation in soils. The inhibiting effect of polluted air can be explained by the presence of carbon monoxide and nitrogen dioxide in it. Sulfur dioxide does not depress the nitrogenase complex of aerobic and anaerobic nitrogen fixing microorganisms.

  16. Isotopes in biological dinitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    Nineteen papers were presented at the conference. Some topics discussed are as follows: biochemistry and genetics of dinitrogen fixation; genetics of the Rhizobium-legume symbiosis and of the nitrogen-fixing bacteria; studies on nonsymbiotic dinitrogen fixation in grass-bacteria associations and blue--green algae; use of /sup 15/N and /sup 13/N for the assay of dinitrogen fixation; effects of management practices on dinitrogen fixation; economy of C and N in nitrogen-fixing legumes; and survey of international and national programs on dinitrogen fixation. (HLW)

  17. The Path of Carbon in Photosynthesis X. Carbon Dioxide Assimilation in Plants

    Science.gov (United States)

    Calvin, M.; Bassham, J. A.; Benson, A. A.; Lynch, V.; Ouellet, C.; Schou, L.; Stepka, W.; Tolbert, N. E.

    1950-04-01

    The conclusions which have been drawn from the results of C{sup 14}O{sub 2} fixation experiments with a variety of plants are developed in this paper. The evidence for thermochemical reduction of carbon dioxide fixation intermediates is presented and the results are interpreted from such a viewpoint.

  18. Fixation distance and fixation duration to vertical road signs.

    Science.gov (United States)

    Costa, Marco; Simone, Andrea; Vignali, Valeria; Lantieri, Claudio; Palena, Nicola

    2018-05-01

    The distance of first-fixation to vertical road signs was assessed in 22 participants while driving a route of 8.34 km. Fixations to road signs were recorded by a mobile eye-movement-tracking device synchronized to GPS and kinematic data. The route included 75 road signs. First-fixation distance and fixation duration distributions were positively skewed. Median distance of first-fixation was 51 m. Median fixation duration was 137 ms with a modal value of 66 ms. First-fixation distance was linearly related to speed and fixation duration. Road signs were gazed at a much closer distance than their visibility distance. In a second study a staircase procedure was used to test the presentation-time threshold that lead to a 75% accuracy in road sign identification. The threshold was 35 ms, showing that short fixations to a road signs could lead to a correct identification. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Requirement of carbon dioxide for initial growth of facultative methylotroph, Acidomonas methanolica MB58.

    Science.gov (United States)

    Mitsui, Ryoji; Katayama, Hiroko; Tanaka, Mitsuo

    2015-07-01

    The facultative methylotrophic bacterium Acidomonas methanolica MB58 can utilize C1 compounds via the ribulose monophosphate pathway. A large gene cluster comprising three components related to C1 metabolism was found in the genome. From upstream, the first was an mxa cluster encoding proteins for oxidation of methanol to formaldehyde; the second was the rmp cluster encoding enzymes for formaldehyde fixation; and the third was the cbb gene cluster encoding proteins for carbon dioxide (CO2) fixation. Examination of CO2 requirements for growth of A. methanolica MB58 cells demonstrated that it did not grow on any carbon source under CO2-free conditions. Measurement of ribulose-1,5-bisphosphate carboxylase activity and RT-PCR analysis demonstrated enzymatic activity was detected in A. methanolica MB58 at growth phase, regardless of carbon sources. However, methanol dehydrogenase and 3-hexlose-6-phosphate synthase expression was regulated by methanol or formaldehyde; it were detected during growth and apparently differed from ribulose-1,5-bisphosphate carboxylase expression. These results suggested that A. methanolica MB58 may be initially dependent on autotrophic growth and that carbon assimilation was subsequently coupled with the ribulose monophosphate pathway at early- to mid-log phases during methylotrophic growth. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  20. Nitrogen fixation in soybean treated with nitrogen dioxide and molybdenum

    International Nuclear Information System (INIS)

    Gupta, G.; Narayanan, R.

    1992-01-01

    Soybean plants were treated with Mo (0.0 or 2.0 mg kg -1 , soil dry wt.) and exposed to NO 2 (0.0, 0.05, or 0.1 μmol mol -1 ) at flowering stage. Specific root nodule activity (SNA), chlorophyll-a (Ch-a), chlorophyll-b (Ch-b), leaf N, number of pods, seeds per pod, weight of seeds, and shoot dry weight were measured. Compared with control, SNA did not change on the addition of 2 mg Mo to the soil, but increased by 65% on exposure to 0.1 μmol -1 NO 2 and by 106% on treatment with both NO 2 and Mo. Both Ch-a and Ch-b increased significantly on exposure to 0.1 μmol -1 NO 2 and 2 mg MO was almost the same as with 0.1 μmol mol -1 NO 2 alone. Leaf-N increased by 46% on exposure to NO 2 but did not change on the addition of Mo. Pod number, seed number and weight, and shoot dry weights showed significantly higher values on exposure to 0.1 μmol mol -1 NO 2 and 2 mg Mo

  1. Photocatalytic fixation of carbon dioxide with poly(3-alkylthiophene)

    Energy Technology Data Exchange (ETDEWEB)

    Kuwabara, T; Kawai, T; Yoshino, K [Osaka University, Osaka (Japan). Faculty of Engineering

    1992-04-05

    The photoirradiation effect of poly(3-hexylthiophene) (P3HT) were studied under CO{sub 2} atmosphere. P3HT film became soluble by photoirradiation in adequate solvents such as ethanol, CHC1{sub 3}, hexane and CH{sub 3}CN under CO{sub 2} atmosphere as well as O{sub 2} atmosphere. This photosolubilization reaction required higher photon energy than the band gap energy of P3HT, and the photoluminescence intensity of P3HT in solvent decreased under CO{sub 2} atmosphere. The solubilized P3HT had larger band gap energy and shorter effective conjugation length than those of original P3HT, and offered an IR absorption peak indicating formation of calbonyl group. These results suggested that electrons transferred from photoexcited P3HT to CO{sub 2} molecules in the first stage of photoinduced reaction. Salicylic acid was obtained by photoirradiation of P3HT in ethanol solution containing phenol indicating the photocatalysis of P3HT. 9 refs., 8 figs.

  2. Reduction of oxidative damages induced by titanium dioxide nanoparticles correlates with induction of the Nrf2 pathway by GSPE supplementation in mice.

    Science.gov (United States)

    Niu, Linpeng; Shao, Mengjiao; Liu, Yuan; Hu, Jinfeng; Li, Ruofan; Xie, Heran; Zhou, Lixiao; Shi, Lei; Zhang, Rong; Niu, Yujie

    2017-09-25

    Titanium dioxide nanoparticles (TiO 2 NPs) are widely used to additives in cosmetics, pharmaceuticals, paints and foods. Recent studies have demonstrated that TiO 2 NPs increased the risk of cancer and the mechanism might relate with oxidative stress. Grape seed procyanidin extract (GSPE) is a natural compound which has been demonstrated to possess a wide array of pharmacological and biochemical actions, including anti-inflammatory, anti-carcinogenic, and antioxidant properties. Our data show that GSPE prevents the changes of histopathology and biomarkers in heart, liver and kidney that occur in mice exposed to TiO 2 NPs. After pretreatment with GSPE, the DNA damage, reactive oxygen species (ROS) generation and malondialdehyde (MDA) content in mice exposed to TiO 2 NPs had statistically significant decreases in dose dependent manners. GSPE increased the expression of nuclear factor erythroid 2 (NF-E2)-related factor 2 (Nrf2), NAD(P)H dehydrogenase[quinine] 1(NQO1), heme oxygenase 1 (HO-1) and glutamate-cysteine ligase catalytic subunit (GCLC). We conclude that grape seed procyanidin extract prevents the majority of tissue and molecular damage resulting from nanoparticle treatment. The protective effect of GSPE may be due to its strong antioxidative activities which related with the activated Nrf2 and its down-regulated genes including NQO1, HO-1 and GCLC. Copyright © 2017 Elsevier B.V. All rights reserved.

  3. Fixation Time for Evolutionary Graphs

    Science.gov (United States)

    Nie, Pu-Yan; Zhang, Pei-Ai

    Evolutionary graph theory (EGT) is recently proposed by Lieberman et al. in 2005. EGT is successful for explaining biological evolution and some social phenomena. It is extremely important to consider the time of fixation for EGT in many practical problems, including evolutionary theory and the evolution of cooperation. This study characterizes the time to asymptotically reach fixation.

  4. Complement fixation test to C burnetii

    Science.gov (United States)

    ... complement fixation test; Coxiella burnetii - complement fixation test; C burnetii - complement fixation test ... a specific foreign substance ( antigen ), in this case, C burnetii . Antibodies defend the body against bacteria, viruses, ...

  5. Eighth international congress on nitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

  6. Sulfur Fixation by Chemically Modified Red Mud Samples Containing Inorganic Additives: A Parametric Study

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2016-01-01

    Full Text Available Sulfur retention ability of Bayer red mud from alumina plant was investigated. Bayer red mud modified by fusel salt and waste mother liquor of sodium ferrocyanide as the main sulfur fixation agent and the calcium based natural mineral materials as servicing additives; the experimental results showed the following: (1 Through 10 wt% waste mother liquor of sodium ferrocyanide modifying Bayer red mud, sulfur fixation rate can increase by 13 wt%. (2 Magnesium oxide can obviously improve the sulfur fixation performance of Bayer red mud and up to a maximum sulfur fixation rate of 47 wt% at adding 1 wt% magnesium oxide. (3 Dolomite enhanced the sulfur fixation performances with the sulfur fixation rate of 68 wt% in optimized condition. (4 Vermiculite dust reduced sulfur dioxide during the fixed-sulfur process of modified Bayer red mud, and the desulphurization ration could reach up to a maximum 76 wt% at 950°C. (5 An advanced three-component sulfur fixation agent was investigated, in which the optimized mass ratio of modified Bayer red mud, dolomite, and vermiculite dust was 70 : 28 : 2 in order, and its sulfur fixation efficiency has reached to a maximum 87 wt% under its 20 wt% dosage in the coal.

  7. Enhancing biological nitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)

    Danso, S.K.A.; Eskew, D.L. (Joint FAO/IAEA Div. of Isotope and Radiation Applications of Atomic Energy for Food and Agricultural Development, Vienna (Austria))

    1984-06-01

    Several co-ordinated research programmes (CRPs) conducted by the Soil Fertility, Irrigation and Crop Production Section of the Joint FAO/IAEA Division have concentrated on finding the most efficient way of applying nitrogen fertilizers to various crops, using nitrogen-15 (/sup 15/N) as a tracer. The findings of these studies have been adopted in many countries around the world, resulting in savings of nitrogen fertilizers worth many millions of dollars every year. More recently, the Section's CRPs have focused on enhancing the natural process of biological di-nitrogen fixation. The /sup 15/N isotope technique has proven to be very valuable in studies of the legume-Rhizobium symbiosis, allowing many more experiments than before to be done and yielding much new practical information. The Soils Section is now working to extend the use of the technique to other nitrogen-fixing symbioses.

  8. Carbon dioxide (CO 2 ) utilizing strain database | Saini | African ...

    African Journals Online (AJOL)

    Culling of excess carbon dioxide from our environment is one of the major challenges to scientific communities. Many physical, chemical and biological methods have been practiced to overcome this problem. The biological means of CO2 fixation using various microorganisms is gaining importance because database of ...

  9. Dinitrogen fixation by blue-green algae from paddy fields

    International Nuclear Information System (INIS)

    Thomas, Joseph

    1977-01-01

    Recent work using radioactive nitrogen on the blue-green algae of paddy fields has been reviewed. These algae fix dinitrogen and photoassimilate carbon evolving oxygen, thereby augmenting nitrogen and carbon status of the soil and also providing oxygen to the water-logged rice paddies. Further studies using radioactive isotopes 13 N, 24 Na and 22 Na on their nitrogen fixation, nitrogen assimilation pathways; regulation of nitrogenase, heterocysts production and sporulation and sodium transport and metabolism have been carried out and reported. The field application of blue green algae for N 2 fixation was found to increase the status of soil nitrogen and yield of paddy. (M.G.B.)

  10. Integrated In Silico Analysis of Pathway Designs for Synthetic Photo-Electro-Autotrophy.

    Directory of Open Access Journals (Sweden)

    Michael Volpers

    Full Text Available The strong advances in synthetic biology enable the engineering of novel functions and complex biological features in unprecedented ways, such as implementing synthetic autotrophic metabolism into heterotrophic hosts. A key challenge for the sustainable production of fuels and chemicals entails the engineering of synthetic autotrophic organisms that can effectively and efficiently fix carbon dioxide by using sustainable energy sources. This challenge involves the integration of carbon fixation and energy uptake systems. A variety of carbon fixation pathways and several types of photosystems and other energy uptake systems can be chosen and, potentially, modularly combined to design synthetic autotrophic metabolism. Prior to implementation, these designs can be evaluated by the combination of several computational pathway analysis techniques. Here we present a systematic, integrated in silico analysis of photo-electro-autotrophic pathway designs, consisting of natural and synthetic carbon fixation pathways, a proton-pumping rhodopsin photosystem for ATP regeneration and an electron uptake pathway. We integrated Flux Balance Analysis of the heterotrophic chassis Escherichia coli with kinetic pathway analysis and thermodynamic pathway analysis (Max-min Driving Force. The photo-electro-autotrophic designs are predicted to have a limited potential for anaerobic, autotrophic growth of E. coli, given the relatively low ATP regenerating capacity of the proton pumping rhodopsin photosystems and the high ATP maintenance of E. coli. If these factors can be tackled, our analysis indicates the highest growth potential for the natural reductive tricarboxylic acid cycle and the synthetic pyruvate synthase-pyruvate carboxylate -glyoxylate bicycle. Both carbon fixation cycles are very ATP efficient, while maintaining fast kinetics, which also results in relatively low estimated protein costs for these pathways. Furthermore, the synthetic bicycles are highly

  11. REVISION ANKLE SYNDESMOSIS FIXATION - FUNCTIONAL OUTCOME AFTER TIGHTROPE ® FIXATION

    Directory of Open Access Journals (Sweden)

    Sendhilvelan Rajagopalan

    2016-07-01

    Full Text Available BACKGROUND Syndesmotic disruptions are often seen in ankle fractures. Malreduction of these fractures can result in arthritis and instability. A proportion of these patients with malreduction require revision fixation. This study presents the results of revision fixation in such patients, using the Ankle TightRope ® (Arthrex system. METHODS Between January 2000 to December 2009, 124 patients who underwent ankle fracture fixations with syndesmotic stabilisation were analysed. Out of 124 patients, 8 patients were diagnosed with failure of primary stabilisation (based on radiological and clinical criteria and subjected to revision fixation using the Ankle TightRope ® (Arthrex system. Followup was done at periodic time intervals of 3, 6 and 12 months. Both clinical and radiological assessment was performed. Complications and duration of hospital stay was recorded. Functional evaluation was performed using the American Orthopaedic Foot and Ankle Society (AOFAS scoring system. RESULTS Five patients had good results, one satisfactory and two had poor outcomes. CONCLUSIONS Ankle TightRope ® fixation is an alternative method of stabilisation in patients who require revision syndesmosis fixation. Further studies are required to evaluate this method of revision stabilisation as compared to screws.

  12. The Protective Effects of the Supercritical-Carbon Dioxide Fluid Extract of Chrysanthemum indicum against Lipopolysaccharide-Induced Acute Lung Injury in Mice via Modulating Toll-Like Receptor 4 Signaling Pathway

    Directory of Open Access Journals (Sweden)

    Xiao-Li Wu

    2014-01-01

    Full Text Available The supercritical-carbon dioxide fluid extract of Chrysanthemum indicum Linné. (CFE has been demonstrated to be effective in suppressing inflammation. The aim of this study is to investigate the preventive action and underlying mechanisms of CFE on acute lung injury (ALI induced by lipopolysaccharide (LPS in mice. ALI was induced by intratracheal instillation of LPS into lung, and dexamethasone was used as a positive control. Results revealed that pretreatment with CFE abated LPS-induced lung histopathologic changes, reduced the wet/dry ratio and proinflammatory cytokines productions (TNF-α, IL-1β, and IL-6, inhibited inflammatory cells migrations and protein leakages, suppressed the levels of MPO and MDA, and upregulated the abilities of antioxidative enzymes (SOD, CAT, and GPx. Furthermore, the pretreatment with CFE downregulated the activations of NF-κB and the expressions of TLR4/MyD88. These results suggested that CFE exerted potential protective effects against LPS-induced ALI in mice and was a potential therapeutic drug for ALI. Its mechanisms were at least partially associated with the modulations of TLR4 signaling pathways.

  13. The Effects of SO2 on N2-Fixation, Carbon Partitioning, and Yield Components in Snapbean, Phaseolus Vulgaris L.

    OpenAIRE

    Griffith, Stephen M.

    1983-01-01

    The primary air pollutant sulfur dioxide has been shown to affect plant biochemistry and physiology, although very little is known about its effects on N2-fixation in legumes. This study was designed to determine if N2-fixation, carbon partitioning , and productivity are affected under short term low level, so2 exposures. Greenhouse grown snapbeans (P has eo lus vulgaris L. cv. Ear l iwax), 29 days from planting, were exposed to 0.0, 0.4, and 0.8 parts per million sulfur dioxide for 4 hour...

  14. Carbon dioxide emissions from the flat bottom and shallow Nam Theun 2 Reservoir: drawdown area as a neglected pathway to the atmosphere

    Science.gov (United States)

    Deshmukh, Chandrashekhar; Guérin, Frédéric; Vongkhamsao, Axay; Pighini, Sylvie; Oudone, Phetdala; Sopraseuth, Saysoulinthone; Godon, Arnaud; Rode, Wanidaporn; Guédant, Pierre; Oliva, Priscia; Audry, Stéphane; Zouiten, Cyril; Galy-Lacaux, Corinne; Robain, Henri; Ribolzi, Olivier; Kansal, Arun; Chanudet, Vincent; Descloux, Stéphane; Serça, Dominique

    2018-03-01

    Freshwater reservoirs are a significant source of CO2 to the atmosphere. CO2 is known to be emitted at the reservoir surface by diffusion at the air-water interface and downstream of dams or powerhouses by degassing and along the river course. In this study, we quantified total CO2 emissions from the Nam Theun 2 Reservoir (Lao PDR) in the Mekong River watershed. The study started in May 2009, less than a year after flooding and just a few months after the maximum level was first reached and lasted until the end of 2013. We tested the hypothesis that soils from the drawdown area would be a significant contributor to the total CO2 emissions.Total inorganic carbon, dissolved and particulate organic carbon and CO2 concentrations were measured in 4 pristine rivers of the Nam Theun watershed, at 9 stations in the reservoir (vertical profiles) and at 16 stations downstream of the monomictic reservoir on a weekly to monthly basis. CO2 bubbling was estimated during five field campaigns between 2009 and 2011 and on a weekly monitoring, covering water depths ranging from 0.4 to 16 m and various types of flooded ecosystems in 2012 and 2013. Three field campaigns in 2010, 2011 and 2013 were dedicated to the soils description in 21 plots and the quantification of soil CO2 emissions from the drawdown area. On this basis, we calculated total CO2 emissions from the reservoir and carbon inputs from the tributaries. We confirm the importance of the flooded stock of organic matter as a source of carbon (C) fuelling emissions. We show that the drawdown area contributes, depending on the year, from 40 to 75 % of total annual gross emissions in this flat and shallow reservoir. Since the CO2 emissions from the drawdown zone are almost constant throughout the years, the large interannual variations result from the significant decrease in diffusive fluxes and downstream emissions between 2010 and 2013. This overlooked pathway in terms of gross emissions would require an in-depth evaluation

  15. Carbon dioxide emissions from the flat bottom and shallow Nam Theun 2 Reservoir: drawdown area as a neglected pathway to the atmosphere

    Directory of Open Access Journals (Sweden)

    C. Deshmukh

    2018-03-01

    Full Text Available Freshwater reservoirs are a significant source of CO2 to the atmosphere. CO2 is known to be emitted at the reservoir surface by diffusion at the air–water interface and downstream of dams or powerhouses by degassing and along the river course. In this study, we quantified total CO2 emissions from the Nam Theun 2 Reservoir (Lao PDR in the Mekong River watershed. The study started in May 2009, less than a year after flooding and just a few months after the maximum level was first reached and lasted until the end of 2013. We tested the hypothesis that soils from the drawdown area would be a significant contributor to the total CO2 emissions.Total inorganic carbon, dissolved and particulate organic carbon and CO2 concentrations were measured in 4 pristine rivers of the Nam Theun watershed, at 9 stations in the reservoir (vertical profiles and at 16 stations downstream of the monomictic reservoir on a weekly to monthly basis. CO2 bubbling was estimated during five field campaigns between 2009 and 2011 and on a weekly monitoring, covering water depths ranging from 0.4 to 16 m and various types of flooded ecosystems in 2012 and 2013. Three field campaigns in 2010, 2011 and 2013 were dedicated to the soils description in 21 plots and the quantification of soil CO2 emissions from the drawdown area. On this basis, we calculated total CO2 emissions from the reservoir and carbon inputs from the tributaries. We confirm the importance of the flooded stock of organic matter as a source of carbon (C fuelling emissions. We show that the drawdown area contributes, depending on the year, from 40 to 75 % of total annual gross emissions in this flat and shallow reservoir. Since the CO2 emissions from the drawdown zone are almost constant throughout the years, the large interannual variations result from the significant decrease in diffusive fluxes and downstream emissions between 2010 and 2013. This overlooked pathway in terms of gross emissions would require

  16. Permanganate Fixation of Plant Cells

    Science.gov (United States)

    Mollenhauer, Hilton H.

    1959-01-01

    In an evaluation of procedures explored to circumvent some of the problems of osmium tetroxide-fixation and methacrylate embedding of plant materials, excised segments of root tips of Zea mays were fixed for electron microscopy in potassium permanganate in the following treatment variations: unbuffered and veronal-acetate buffered solutions of 0.6, 2.0, and 5.0 per cent KMnO4 at pH 5.0, 6.0, 6.7, and 7.5, and temperatures of 2–4°C. and 22°C. After fixation the segments were dehydrated, embedded in epoxy resin, sectioned, and observed or photographed. The cells of the central region of the rootcap are described. The fixation procedures employing unbuffered solutions containing 2.0 to 5.0 per cent KMnO4 at a temperature of 22°C. gave particularly good preservation of cell structure and all membrane systems. Similar results were obtained using a solution containing 2.0 per cent KMnO4, buffered with veronal-acetate to pH 6.0, and a fixation time of 2 hours at 22°C. The fixation procedure utilizing veronal-acetate buffered, 0.6 per cent KMnO4 at 2–4°C. and pH 6.7 also gave relatively good preservation of most cellular constituents. However, preservation of the plasma membrane was not so good, nor was the intensity of staining so great, as that with the group of fixatives containing greater concentrations of KMnO4. The other fixation procedures did not give satisfactory preservation of fine structure. A comparison is made of cell structures as fixed in KMnO4 or OsO4. PMID:14423414

  17. External fixation of "intertrochanteric" fractures.

    Science.gov (United States)

    Gani, Naseem Ul; Kangoo, Khursheed Ahmed; Bashir, Arshad; Muzaffer, Rahil; Bhat, Mohammad Farooq; Farooq, Munir; Badoo, Abdul Rashid; Dar, Imtiyaz Hussian; Wani, Mudassir Maqbool

    2009-10-10

    In developing countries, due to limited availability of modern anesthesia and overcrowding of the hospitals with patients who need surgery, high-risk patients with "intertrochanteric" fractures remain unsuita ble for open reduction and internal fixation.The aim of this study was to analyze the results of external fixation of "intertrochanteric" fractures in high-risk geriatric patients in a developing country.The results of 62 ambulatory high-risk geriatric patients with a mean age of 70 years (range 58-90 years) with "intertrochanteric" fractures, in whom external fixation was performed, are reported.Eight patients died during follow-up due to medical causes unrelated to the surgical procedure. So only 54 patients were available for final assessment. Procedure is simple, performed under local anesthesia, requires less time for surgery and is associated with less blood loss. Good fixation and early ambulation was achieved in most of the patients. Average time to union was 14 weeks. Thirty-one patients developed superficial pin tract infection and 28 patients had average shortening of 15 mm due to impaction and varus angulation. Functional outcome was assessed using Judet's point system. Good to excellent results were achieved in 44 patients.This study demonstrated that external fixation of "intertrochantric" fractures performed under local anesthesia offers significant advantage in ambulatory high-risk geriatric patients especially in a developing country.

  18. Proteomic analysis of carbon concentrating chemolithotrophic bacteria Serratia sp. for sequestration of carbon dioxide.

    Science.gov (United States)

    Bharti, Randhir K; Srivastava, Shaili; Thakur, Indu Shekhar

    2014-01-01

    A chemolithotrophic bacterium enriched in the chemostat in presence of sodium bicarbonate as sole carbon source was identified as Serratia sp. by 16S rRNA sequencing. Carbon dioxide sequestering capacity of bacterium was detected by carbonic anhydrase enzyme and ribulose-1, 5- bisphosphate carboxylase/oxygenase (RuBisCO). The purified carbonic anhydrase showed molecular weight of 29 kDa. Molecular weight of RuBisCO was 550 kDa as determined by fast protein liquid chromatography (FPLC), however, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed presence of two subunits whose molecular weights were 56 and 14 kDa. The Western blot analysis of the crude protein and purified sample cross reacted with RuBisCO large-subunit polypeptides antibodies showed strong band pattern at molecular weight around 56 kDa regions. Whole cell soluble proteins of Serratia sp. grown under autotrophic and heterotrophic conditions were resolved by two-dimensional gel electrophoresis and MALDI-TOF/MS for differential expression of proteins. In proteomic analysis of 63 protein spots, 48 spots were significantly up-regulated in the autotrophically grown cells; seven enzymes showed its utilization in autotrophic carbon fixation pathways and other metabolic activities of bacterium including lipid metabolisms indicated sequestration potency of carbon dioxide and production of biomaterials.

  19. Proteomic analysis of carbon concentrating chemolithotrophic bacteria Serratia sp. for sequestration of carbon dioxide.

    Directory of Open Access Journals (Sweden)

    Randhir K Bharti

    Full Text Available A chemolithotrophic bacterium enriched in the chemostat in presence of sodium bicarbonate as sole carbon source was identified as Serratia sp. by 16S rRNA sequencing. Carbon dioxide sequestering capacity of bacterium was detected by carbonic anhydrase enzyme and ribulose-1, 5- bisphosphate carboxylase/oxygenase (RuBisCO. The purified carbonic anhydrase showed molecular weight of 29 kDa. Molecular weight of RuBisCO was 550 kDa as determined by fast protein liquid chromatography (FPLC, however, sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE showed presence of two subunits whose molecular weights were 56 and 14 kDa. The Western blot analysis of the crude protein and purified sample cross reacted with RuBisCO large-subunit polypeptides antibodies showed strong band pattern at molecular weight around 56 kDa regions. Whole cell soluble proteins of Serratia sp. grown under autotrophic and heterotrophic conditions were resolved by two-dimensional gel electrophoresis and MALDI-TOF/MS for differential expression of proteins. In proteomic analysis of 63 protein spots, 48 spots were significantly up-regulated in the autotrophically grown cells; seven enzymes showed its utilization in autotrophic carbon fixation pathways and other metabolic activities of bacterium including lipid metabolisms indicated sequestration potency of carbon dioxide and production of biomaterials.

  20. Comparison of Outcomes of Operatively Treated Bicondylar Tibial Plateau Fractures by External Fixation and Internal Fixation

    Directory of Open Access Journals (Sweden)

    CC Chan

    2012-03-01

    Full Text Available The outcome of bicondylar tibial plateau fractures treated with either external fixation (35 patients or internal fixation (24 patients was reviewed. Outcome measures included the Rasmussen score, clinical complications, development of osteoarthritis and the requirement for total knee replacement (TKR. Twenty-two (92% anatomical reductions were achieved in the internal fixation group compared to 27 (77% in the external fixation group. Infective complications were more common in the external fixation group (9 patients, 26% due to pin tract infection. There were no deep infections in the internal fixation group. The mean Rasmussen score was not significantly different (mean score 32 in external fixation and 29 in internal fixation between the two groups and the incidence of osteoarthritis was the same in both groups. Four patients in the external fixation group underwent a TKR compared to 5 patients in the internal fixation group. Bicondylar tibial plateau fractures have similar outcomes following external or internal fixation.

  1. Carbon Dioxide Mitigation by Microalgal Photosynthesis

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Mijeong Lee; Gillis, James M.; Hwang, Jiann Yang [Michigan Technological University, Houghton (United States)

    2003-12-15

    Algal growth studies of Chlorella strains were conducted in a batch mode with bench type experiments. Carbon dioxide fixation rates of the following green microalgae were determined: Chlorella sp. H84, Chlorella sp. A2, Chlorella sorokiniana UTEX 1230, Chlorella vulgaris, and Chlorella pyrenoidosa. C. vulgaris, among other strains of microalgae, showed the highest growth rate (1.17 optical density/5 days). Cultivating conditions for C. vulgaris that produced the highest growth rate were at concentrations of 243 μg CO{sub 2}/mL, 10 mM ammonia, and 1 mM phosphate, with an initial pH range of 7-8.

  2. Report on a survey in fiscal 1999. Supplementary survey on research and development of carbon dioxide fixation and effective utilization technologies utilizing bacteria and algae (the survey on feasibility of bio-technologies to create economic effects, such as the biological CO2 fixation technology); 1999 nendo saikin sorui nado riyo nisanka tanso koteika yuko riyo gijutsu kenkyu kaihatsu futai chosa. Keizaiteki koka wo soshutsusuru seibutsuteki CO{sub 2} koteigijutsu nado no biotechnology no kanosei chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Bio-technologies including the biological CO2 fixation technology, or the green bio-technologies (GBT) are the technologies indispensable in realizing the change to a resource circulating and environment harmonizing society that accompanies economical growth, or in other words, the 'sustainable development'. In quantifying the feasibility of these technologies, the GBTs that contribute to creating Japan's international competitive power and employment were specified, and an approach to establish the realization target in 2010 was adopted, upon identifying the general condition of the related markets inside and outside the country. The GBT is the technology that makes the best use of Japan's independent strength created by combining the enzyme engineering and fermentation engineering with the 'genome science' (HEART). The targets are to substitute four million kiloliters of petroleum with a resource circulation type energy generated by the bio-technology; apply the bio-technology to about 30% of products and processes produced or used in Japan's chemical industries; and aim at creating markets by using environmental measurement and analysis, treatment of hard-to-decompose substances, and supports on tree planting as the three pillars. A simulation on return on investment in GBT business suggests the effect of promoting PFI. (NEDO)

  3. Report on a survey in fiscal 1999. Supplementary survey on research and development of carbon dioxide fixation and effective utilization technologies utilizing bacteria and algae (the survey on feasibility of bio-technologies to create economic effects, such as the biological CO2 fixation technology); 1999 nendo saikin sorui nado riyo nisanka tanso koteika yuko riyo gijutsu kenkyu kaihatsu futai chosa. Keizaiteki koka wo soshutsusuru seibutsuteki CO{sub 2} koteigijutsu nado no biotechnology no kanosei chosa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-03-01

    Bio-technologies including the biological CO2 fixation technology, or the green bio-technologies (GBT) are the technologies indispensable in realizing the change to a resource circulating and environment harmonizing society that accompanies economical growth, or in other words, the 'sustainable development'. In quantifying the feasibility of these technologies, the GBTs that contribute to creating Japan's international competitive power and employment were specified, and an approach to establish the realization target in 2010 was adopted, upon identifying the general condition of the related markets inside and outside the country. The GBT is the technology that makes the best use of Japan's independent strength created by combining the enzyme engineering and fermentation engineering with the 'genome science' (HEART). The targets are to substitute four million kiloliters of petroleum with a resource circulation type energy generated by the bio-technology; apply the bio-technology to about 30% of products and processes produced or used in Japan's chemical industries; and aim at creating markets by using environmental measurement and analysis, treatment of hard-to-decompose substances, and supports on tree planting as the three pillars. A simulation on return on investment in GBT business suggests the effect of promoting PFI. (NEDO)

  4. Radiation induced sulfur dioxide removal

    International Nuclear Information System (INIS)

    Chmielewski, A.G.

    2000-01-01

    The biggest source of air pollution is the combustion of fossil fuels, were pollutants such as particulate, sulfur dioxide (SO 2 ), nitrogen oxides (NO x ), and volatile organic compounds (VOC) are emitted. Among these pollutants, sulfur dioxide plays the main role in acidification of the environment. The mechanism of sulfur dioxide transformation in the environment is partly photochemical. This is not direct photooxidation, however, but oxidation through formed radicals. Heterogenic reactions play an important role in this transformation as well; therefore, observations from environmental chemistry can be used in air pollution control engineering. One of the most promising technologies for desulfurization of the flue gases (and simultaneous denitrification) is radiation technology with an electron accelerator application. Contrary to the nitrogen oxides (NO x ) removal processes, which is based on pure radiation induced reactions, sulfur dioxide removal depends on two pathways: a thermochemical reaction in the presence of ammonia/water vapor and a radiation set of radiochemical reactions. The mechanism of these reactions and the consequent technological parameters of the process are discussed in this paper. The industrial application of this radiation technology is being implemented in an industrial pilot plant operated by INCT at EPS Kaweczyn. A full-scale industrial plant is currently in operation in China, and two others are under development in Japan and Poland. (author)

  5. Understanding Nitrogen Fixation

    Energy Technology Data Exchange (ETDEWEB)

    Paul J. Chirik

    2012-05-25

    synthesis of ammonia, NH{sub 3}, from its elements, H{sub 2} and N{sub 2}, via the venerable Haber-Bosch process is one of the most significant technological achievements of the past century. Our research program seeks to discover new transition metal reagents and catalysts to disrupt the strong N {triple_bond} N bond in N{sub 2} and create new, fundamental chemical linkages for the construction of molecules with application as fuels, fertilizers and fine chemicals. With DOE support, our group has discovered a mild method for ammonia synthesis in solution as well as new methods for the construction of nitrogen-carbon bonds directly from N{sub 2}. Ideally these achievements will evolve into more efficient nitrogen fixation schemes that circumvent the high energy demands of industrial ammonia synthesis. Industrially, atmospheric nitrogen enters the synthetic cycle by the well-established Haber-Bosch process whereby N{sub 2} is hydrogenated to ammonia at high temperature and pressure. The commercialization of this reaction represents one of the greatest technological achievements of the 20th century as Haber-Bosch ammonia is responsible for supporting approximately 50% of the world's population and serves as the source of half of the nitrogen in the human body. The extreme reaction conditions required for an economical process have significant energy consequences, consuming 1% of the world's energy supply mostly in the form of pollution-intensive coal. Moreover, industrial H{sub 2} synthesis via the water gas shift reaction and the steam reforming of methane is fossil fuel intensive and produces CO{sub 2} as a byproduct. New synthetic methods that promote this thermodynamically favored transformation ({Delta}G{sup o} = -4.1 kcal/mol) under milder conditions or completely obviate it are therefore desirable. Most nitrogen-containing organic molecules are derived from ammonia (and hence rely on the Haber-Bosch and H{sub 2} synthesis processes) and direct synthesis from

  6. Iodide-photocatalyzed reduction of carbon dioxide to formic acid with thiols and hydrogen sulfide

    OpenAIRE

    Berton, Mateo Otao; Mello, Rossella C. C.; González Núñez, María Elena

    2016-01-01

    The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low-pressure mercury lamp. This transition-metal-free photocatalytic process for CO2 capture coupled with H2S removal may have been relevant as a prebiotic carbon dioxide fixation.

  7. Anterior fixation of the axis.

    Science.gov (United States)

    Traynelis, Vincent C; Fontes, Ricardo B V

    2010-09-01

    Although anterior fixation of the axis is not commonly performed, plate fixation of C2 is an important technique for treating select upper cervical traumatic injuries and is also useful in the surgical management of spondylosis. To report the technique and outcomes of C2 anterior plate fixation for a series of patients in which the majority presented with symptomatic degenerative spondylosis. Forty-six consecutive patients underwent single or multilevel fusions over a 7-year period; 30 of these had advanced degenerative disease manifested by myelopathy or deformity. Exposure was achieved with rostral extension of the standard anterior cervical exposure via careful soft tissue dissection, mobilization of the superior thyroid artery, and the use of a table-mounted retractor. It was not necessary to remove the submandibular gland, section the digastric muscle, or make additional skin incisions. Screws were placed an average of 4.6 mm (+/- 2.3 mm) from the inferior C2 endplate with a mean sagittal trajectory of 15.7 degrees (+/- 7.6 degrees). Short- and long-term procedure-related mortality was 4.4%, and perioperative morbidity was 8.9%. Patients remained intubated an average of 2.5 days following surgery. Dysphagia was initially reported by 15.2% of patients but resolved by the 8th postoperative week in all patients. Arthrodesis was achieved in all patients available for long-term follow-up. Multilevel fusions were not associated with longer hospitalization or morbidity. Anterior plate fixation of the axis for degenerative disease can be accomplished with acceptable morbidity employing an extension of the standard anterolateral route.

  8. Smaller Fixation Target Size Is Associated with More Stable Fixation and Less Variance in Threshold Sensitivity.

    Directory of Open Access Journals (Sweden)

    Kazunori Hirasawa

    Full Text Available The aims of this randomized observational case control study were to quantify fixation behavior during standard automated perimetry (SAP with different fixation targets and to evaluate the relationship between fixation behavior and threshold variability at each test point in healthy young participants experienced with perimetry. SAP was performed on the right eyes of 29 participants using the Octopus 900 perimeter, program 32, dynamic strategy. The fixation targets of Point, Cross, and Ring were used for SAP. Fixation behavior was recorded using a wearable eye-tracking glass. All participants underwent SAP twice with each fixation target in a random fashion. Fixation behavior was quantified by calculating the bivariate contour ellipse area (BCEA and the frequency of deviation from the fixation target. The BCEAs (deg2 of Point, Cross, and Ring targets were 1.11, 1.46, and 2.02, respectively. In all cases, BCEA increased significantly with increasing fixation target size (p < 0.05. The logarithmic value of BCEA demonstrated the same tendency (p < 0.05. A positive correlation was identified between fixation behavior and threshold variability for the Point and Cross targets (ρ = 0.413-0.534, p < 0.05. Fixation behavior increased with increasing fixation target size. Moreover, a larger fixation behavior tended to be associated with a higher threshold variability. A small fixation target is recommended during the visual field test.

  9. Functional ecology of free-living nitrogen fixation: A contemporary perspective

    Science.gov (United States)

    Reed, Sasha C.; Cleveland, Cory C.; Townsend, Alan R.

    2011-01-01

    Nitrogen (N) availability is thought to frequently limit terrestrial ecosystem processes, and explicit consideration of N biogeochemistry, including biological N2 fixation, is central to understanding ecosystem responses to environmental change. Yet, the importance of free-living N2 fixation—a process that occurs on a wide variety of substrates, is nearly ubiquitous in terrestrial ecosystems, and may often represent the dominant pathway for acquiring newly available N—is often underappreciated. Here, we draw from studies that investigate free-living N2 fixation from functional, physiological, genetic, and ecological perspectives. We show that recent research and analytical advances have generated a wealth of new information that provides novel insight into the ecology of N2 fixation as well as raises new questions and priorities for future work. These priorities include a need to better integrate free-living N2 fixation into conceptual and analytical evaluations of the N cycle's role in a variety of global change scenarios.

  10. Overcoming fixation with repeated memory suppression.

    Science.gov (United States)

    Angello, Genna; Storm, Benjamin C; Smith, Steven M

    2015-01-01

    Fixation (blocks to memories or ideas) can be alleviated not only by encouraging productive work towards a solution, but, as the present experiments show, by reducing counterproductive work. Two experiments examined relief from fixation in a word-fragment completion task. Blockers, orthographically similar negative primes (e.g., ANALOGY), blocked solutions to word fragments (e.g., A_L_ _GY) in both experiments. After priming, but before the fragment completion test, participants repeatedly suppressed half of the blockers using the Think/No-Think paradigm, which results in memory inhibition. Inhibiting blockers did not alleviate fixation in Experiment 1 when conscious recollection of negative primes was not encouraged on the fragment completion test. In Experiment 2, however, when participants were encouraged to remember negative primes at fragment completion, relief from fixation was observed. Repeated suppression may nullify fixation effects, and promote creative thinking, particularly when fixation is caused by conscious recollection of counterproductive information.

  11. Carbon dioxide as chemical feedstock

    National Research Council Canada - National Science Library

    Aresta, M

    2010-01-01

    ... Dioxide as an Inert Solvent for Chemical Syntheses 15 Alessandro Galia and Giuseppe Filardo Introduction 15 Dense Carbon Dioxide as Solvent Medium for Chemical Processes 15 Enzymatic Catalysis in Dense Carbon Dioxide 18 Other Reactions in Dense Carbon Dioxide 19 Polymer Synthesis in Supercritical Carbon Dioxide 20 Chain Polymerizations: Synt...

  12. Polymeric media for tritium fixation. Supplement I

    International Nuclear Information System (INIS)

    Franz, J.A.; Burger, L.L.

    1976-01-01

    Procedures for the fixation of tritium as TH or THO in two different polymeric media are described. The complete procedure for THO fixation in a polyureylene-polyurethane polumer, including polymer molding procedures and leach tests is presented. The catalytic tritiation of polystyrene under very mild conditions using a rhodium catalyst is also described. Thermal stabilities and cost estimates for the polymers examined under this program are discussed. Organic polymers were found to have attractive features for the fixation and storage of concentrated tritium wastes due to the convenience of fixation procedures and favorable properties of the resulting media

  13. Modeling fixation locations using spatial point processes.

    Science.gov (United States)

    Barthelmé, Simon; Trukenbrod, Hans; Engbert, Ralf; Wichmann, Felix

    2013-10-01

    Whenever eye movements are measured, a central part of the analysis has to do with where subjects fixate and why they fixated where they fixated. To a first approximation, a set of fixations can be viewed as a set of points in space; this implies that fixations are spatial data and that the analysis of fixation locations can be beneficially thought of as a spatial statistics problem. We argue that thinking of fixation locations as arising from point processes is a very fruitful framework for eye-movement data, helping turn qualitative questions into quantitative ones. We provide a tutorial introduction to some of the main ideas of the field of spatial statistics, focusing especially on spatial Poisson processes. We show how point processes help relate image properties to fixation locations. In particular we show how point processes naturally express the idea that image features' predictability for fixations may vary from one image to another. We review other methods of analysis used in the literature, show how they relate to point process theory, and argue that thinking in terms of point processes substantially extends the range of analyses that can be performed and clarify their interpretation.

  14. Methanotrophy induces nitrogen fixation during peatland development

    Science.gov (United States)

    Larmola, Tuula; Leppänen, Sanna M.; Tuittila, Eeva-Stiina; Aarva, Maija; Merilä, Päivi; Fritze, Hannu; Tiirola, Marja

    2014-01-01

    Nitrogen (N) accumulation rates in peatland ecosystems indicate significant biological atmospheric N2 fixation associated with Sphagnum mosses. Here, we show that the linkage between methanotrophic carbon cycling and N2 fixation may constitute an important mechanism in the rapid accumulation of N during the primary succession of peatlands. In our experimental stable isotope enrichment study, previously overlooked methane-induced N2 fixation explained more than one-third of the new N input in the younger peatland stages, where the highest N2 fixation rates and highest methane oxidation activities co-occurred in the water-submerged moss vegetation. PMID:24379382

  15. [Comparison of external fixation with or without limited internal fixation for open knee fractures].

    Science.gov (United States)

    Li, K N; Lan, H; He, Z Y; Wang, X J; Yuan, J; Zhao, P; Mu, J S

    2018-03-01

    Objective: To explore the characteristics and methods of different fixation methods and prevention of open knee joint fracture. Methods: The data of 86 cases of open knee joint fracture admitted from January 2002 to December 2015 in Department of Orthopaedics, Affiliated Hospital of Chengdu University were analyzed retrospectively.There were 65 males and 21 females aged of 38.6 years. There were 38 cases treated with trans articular external fixation alone, 48 cases were in the trans articular external fixation plus auxiliary limited internal fixation group. All the patients were treated according to the same three stages except for different fixation methods. Observation of external fixation and fracture fixation, fracture healing, wound healing and treatment, treatment and related factors of infection control and knee function recovery. χ(2) test was used to analyze data. Results: Eleven patients had primary wound healing, accounting for 12.8%. Seventy-five patients had two wounds healed, accounting for 87.2%. Only 38 cases of trans articular external fixator group had 31 cases of articular surface reduction, accounting for 81.6%; Five cases of trans articular external fixator assisted limited internal fixation group had 5 cases of poor reduction, accounting for 10.4%; There was significant difference between the two groups (χ(2)=44.132, P external fixation group, a total of 23 cases of patients with infection, accounted for 60.5% of external fixation group; trans articular external fixation assisted limited internal fixation group there were 30 cases of patients with infection, accounting for the assistance of external fixator and limited internal fixation group 62.5%; There was significant difference between the two groups(χ(2)=0.035, P >0.05). Five cases of fracture nonunion cases of serious infection, patients voluntarily underwent amputation. The Lysholm Knee Scale: In the external fixation group, 23 cases were less than 50 points, accounting for 60

  16. Uranium dioxide pellets

    International Nuclear Information System (INIS)

    Zawidzki, T.W.

    1979-01-01

    Sintered uranium dioxide pellets composed of particles of size > 50 microns suitable for power reactor use are made by incorporating a small amount of sulphur into the uranium dioxide before sintering. The increase in grain size achieved results in an improvement in overall efficiency when such pellets are used in a power reactor. (author)

  17. Classification of titanium dioxide

    International Nuclear Information System (INIS)

    Macias B, L.R.; Garcia C, R.M.; Maya M, M.E.; Ita T, A. De; Palacios G, J.

    2002-01-01

    In this work the X-ray diffraction (XRD), Scanning Electron Microscopy (Sem) and the X-ray Dispersive Energy Spectroscopy techniques are used with the purpose to achieve a complete identification of phases and mixture of phases of a crystalline material as titanium dioxide. The problem for solving consists of being able to distinguish a sample of titanium dioxide being different than a titanium dioxide pigment. A standard sample of titanium dioxide with NIST certificate is used, which indicates a purity of 99.74% for the TiO 2 . The following way is recommended to proceed: a)To make an analysis by means of X-ray diffraction technique to the sample of titanium dioxide pigment and on the standard of titanium dioxide waiting not find differences. b) To make a chemical analysis by the X-ray Dispersive Energy Spectroscopy via in a microscope, taking advantage of the high vacuum since it is oxygen which is analysed and if it is concluded that the aluminium oxide appears in a greater proportion to 1% it is established that is a titanium dioxide pigment, but if it is lesser then it will be only titanium dioxide. This type of analysis is an application of the nuclear techniques useful for the tariff classification of merchandise which is considered as of difficult recognition. (Author)

  18. Carbon fixation and isotope discrimination by a crassulacean plant: dependence on the photoperiod.

    Science.gov (United States)

    Lerman, J C; Queiroz, O

    1974-03-22

    Variations of more than 1 percent are observed in the carbon-13 to carbon-12 ratio of extracts of leaves of the succulent Kalanchoe blossfeldiana when the photoperiod is changed from long to short days. This indicates that the mechanism of carbon fixation switches from the Calvin (C(3)) pathway to the Hatch-Slack (C(4)) pathway of primary enzymic operation. The variations observed in the isotope compositions are tentatively explained by a model.

  19. Improper tube fixation causing a leaky cuff

    Directory of Open Access Journals (Sweden)

    Gupta Babita

    2010-01-01

    Full Text Available Leaking endotracheal tube cuffs are common problems in intensive care units. We report a case wherein the inflation tube was damaged by the adhesive plaster used for tube fixation and resulted in leaking endotracheal tube cuff. We also give some suggestions regarding the tube fixation and some remedial measures for damaged inflation system.

  20. Nitrogen fixation by legumes in retorted shale

    Energy Technology Data Exchange (ETDEWEB)

    Hersman, L E; Molitoris, E; Klein, D A

    1981-01-01

    A study was made to determine whether retorted shale additions would significantly affect symbiotic N/sub 2/ fixation. Results indicate that small additions of the shale may stimulate plant growth but with higher concentrations plants are stressed, resulting in a decreased biomass and a compensatory effect of an increased number of nodules and N/sub 2/ fixation potential. (JMT)

  1. Outcome of rail fixator system in reconstructing bone gap

    Directory of Open Access Journals (Sweden)

    Amit Lakhani

    2014-01-01

    Conclusion: All patients well tolerated rail fixator with good functional results and gap reconstruction. Easy application of rail fixator and comfortable distraction procedure suggest rail fixator a good alternative for gap reconstruction of limbs.

  2. EFFECT OF EMBEDDING METHODS VERSUS FIXATIVE TYPE ON KARYOMETRIC MEASURES

    NARCIS (Netherlands)

    BOON, ME; VANDERPOEL, HG; TAN, CJA; KOK, LP

    The influence of fixation and embedding methods in seven urologic tumor samples was studied karyometrically for 12 preparatory techniques. Routine histologic formalin fixation was compared with Carbowax and Kryofix fixatives. Also, histologic material was studied embedded in paraffin and plastic

  3. Fiscal 1993 report on results of R and D on innovative technology for producing advanced biomaterial. Peptide applied carbon dioxide fixation/effective utilization technology (Second volume: comprehensive investigation and research); 1993 nendo senshin bio zairyo no sosei kako gijutsu no kenkyu kaihatsu seika hokokusho (sogo chosa kenkyu). 2. Peptide oyo nisanka tanso koteika yuko riyo gijutsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-03-01

    Technology was developed for preparing functional materials by synthesizing new functional peptides in which non-natural amino acid needed for the functional manifestation was introduced, and by fixing the peptides to the surface of a base plate such as silica glass or modifying the surface with them. As the related technological investigation, the following six areas were surveyed. (1) Structural design of peptides, (2) synthesis of peptides by chemical and enzyme methods, (3) synthesis of non-natural amino acid and its introduction into peptides, (4) structural analysis of peptides, (5) physiological activity of peptides, and (6) materialization and functional manifestation of peptides. With the exception of the area (5) consisting of one advanced research case, other areas were constituted of analysis, general remarks and research cases. The area (6) was constituted of materialization technique 1 and 2, film function and peptide, catalytic action 1 and 2, and one research case; the materialization technique was defined as a technique for modifying the surface of a synthetic resin, metallic or silica glass substrate with functional peptides; and an explanation was given to the present state of the fixation, pattern formation and integration technologies. (NEDO)

  4. Eighth international congress on nitrogen fixation. Final program

    Energy Technology Data Exchange (ETDEWEB)

    1990-12-31

    This volume contains the proceedings of the Eighth International Congress on Nitrogen Fixation held May 20--26, 1990 in Knoxville, Tennessee. The volume contains abstracts of individual presentations. Sessions were entitled Recent Advances in the Chemistry of Nitrogen Fixation, Plant-microbe Interactions, Limiting Factors of Nitrogen Fixation, Nitrogen Fixation and the Environment, Bacterial Systems, Nitrogen Fixation in Agriculture and Industry, Plant Function, and Nitrogen Fixation and Evolution.

  5. The LysR-type transcriptional regulator CbbR controlling autotrophic CO2 fixation by Xanthobacter flavus is an NADPH sensor

    NARCIS (Netherlands)

    van Keulen, G; Girbal, L; van den Bergh, E.R E; Dijkhuizen, L.; Meijer, W.G

    Autotrophic growth of Xanthobacter flavus is dependent on the fixation of carbon dioxide via the Calvin cycle and on the oxidation of simple organic and inorganic compounds to provide the cell with energy. Maximal induction of the cbb and gap-pgk operons encoding enzymes of the Calvin cycle occurs

  6. Polymeric media for tritium fixation

    International Nuclear Information System (INIS)

    Franz, J.A.; Burger, L.L.

    1975-01-01

    The synthesis and leach testing of several polymeric media for tritium fixation are presented. Tritiated bakelite, poly(acrylonitrile) and polystyrene successfully fixed tritium. Tritium leach rates at the tracer level appear to be negligible. Advantages and disadvantages of the processes are discussed, and further bench-scale investigations underway are reported. Rough cost estimates are presented for the different media and are compared with alternate approaches such as deep-well injection and long-term tank storage. Polymeric media costs are high compared to deep-well storage and are of the same order of magnitude per liter of water as for isotopic enrichment. With this limitation, polymeric media can be economically feasible only for highly concentrated tritiated wastes. It is recommended that the bakelite and polystyrene processes be examined on a larger scale to permit more accurate cost analysis and process design. (auth)

  7. Carbon dioxide efflux from leaves in light and darkness

    Energy Technology Data Exchange (ETDEWEB)

    Holmgren, P; Jarvis, P G

    1967-01-01

    The efflux of carbon dioxide in light and darkness was measured at low ambient CO/sub 2/ concentrations in leaves of Rumex acetosa. Light carbon dioxide production (photorespiration) was found to depend on irradiance and to differ from dark production as to the response to temperature and ambient concentrations of O/sub 2/ and CO/sub 2/. These observations support previously made suggestions that photorespiration follows a different metabolic pathway to dark respiration.

  8. Dinitrogen fixation in aphotic oxygenated marine environments

    Directory of Open Access Journals (Sweden)

    Eyal eRahav

    2013-08-01

    Full Text Available We measured N2 fixation rates from oceanic zones that have traditionally been ignored as sources of biological N2 fixation; the aphotic, fully oxygenated, nitrate (NO3--rich, waters of the oligotrophic Levantine Basin (LB and the Gulf of Aqaba (GA. N2 fixation rates measured from pelagic aphotic waters to depths up to 720 m, during the mixed and stratified periods, ranged from 0.01 nmol N L-1 d-1 to 0.38 nmol N L-1 d-1. N2 fixation rates correlated significantly with bacterial productivity and heterotrophic diazotrophs were identified from aphotic as well as photic depths. Dissolved free amino acid amendments to whole water from the GA enhanced bacterial productivity by 2to 3.5 and N2 fixation rates by ~ 2 fold in samples collected from aphotic depths while in amendments to water from photic depths bacterial productivity increased 2 to 6 fold while N2 fixation rates increased by a factor of 2 to 4 illustrating that both BP an heterotrophic N2 fixation are carbon limited. Experimental manipulations of aphotic waters from the LB demonstrated a significant positive correlation between transparent exopolymeric particles (TEP concentration and N2 fixation rates. This suggests that sinking organic material and high carbon (C: nitrogen (N micro-environments (such as TEP-based aggregates or marine snow could support high heterotrophic N2 fixation rates in oxygenated surface waters and in the aphotic zones. Indeed, our calculations show that aphotic N2 fixation accounted for 37 to 75 % of the total daily integrated N2 fixation rates at both locations in the Mediterranean and Red Seas with rates equal or greater to those measured from the photic layers. Moreover, our results indicate that that while N2 fixation may be limited in the surface waters, aphotic, pelagic N2 fixation may contribute significantly to new N inputs in other oligotrophic basins, yet it is currently not included in regional or global N budgets.

  9. Immaturity of Visual Fixations in Dyslexic Children.

    Directory of Open Access Journals (Sweden)

    TIADI eBi Kuyami Guy Aimé

    2016-02-01

    Full Text Available To our knowledge, behavioral studies recording visual fixations abilities in dyslexic children are scarce. The object of this paper is to explore further the visual fixation ability in dyslexics compared to chronological age-matched and reading age-matched non-dyslexic children. Fifty-five dyslexic children from 7 to 14 years old, fifty-five chronological age-matched non-dyslexic children and fifty-five reading age-matched non-dyslexic children participated to this study. Eye movements from both eyes were recorded horizontally and vertically by a video-oculography system (EyeBrain® T2. The fixation task consisted in fixating a white-filled circle appearing in the centre of the screen for 30 seconds. Results showed that dyslexic children produced a significantly higher number of unwanted saccades than both groups of non-dyslexic children. Moreover, the number of unwanted saccades significantly decreased with age in both groups of non-dyslexic children, but not in dyslexics. Furthermore, dyslexics made more saccades during the last 15 sec of fixation period with respect to both groups of non-dyslexic children. Such poor visual fixation capability in dyslexic children could be due to impaired attention abilities, as well as to an immaturity of the cortical areas controlling the fixation system.

  10. Sutureless Intrascleral Fixated Intraocular Lens Implantation.

    Science.gov (United States)

    Karadag, Remzi; Celik, Haci Ugur; Bayramlar, Huseyin; Rapuano, Christopher J

    2016-08-01

    To review sutureless intrascleral intraocular lens (IOL) fixation methods. Review of published literature. Sutureless intrascleral IOL fixation methods are newer and have been developed to eliminate the suture-related complications of sutured scleral fixation methods such as suture-induced inflammation or infection and IOL dislocation or subluxation due to suture degradation or suture breakage. Sutureless intrascleral fixation methods aim for intrascleral haptic fixation to achieve stability of the IOL. Various methods of sutureless scleral fixation have been described. Using a needle, a blade, or a trochar, sclerostomies are created in all techniques for intraocular access. Some surgeons prefer to create scleral tunnels, whereas others use scleral flaps for scleral fixation of haptics. The stability of IOLs is attained by the scar tissue formed around the haptics. Short-term results of these new methods are acceptable; studies including more cases with longer follow-up are needed to determine their long-term success. [J Cataract Refract Surg. 2016;32(9):586-597.]. Copyright 2016, SLACK Incorporated.

  11. Nitrogen fixation in arctic marine sediments: effect of oil and hydrocarbon fractions

    Energy Technology Data Exchange (ETDEWEB)

    Knowles, R; Wishart, C

    1977-06-01

    Nitrogen fixation (acetylene reduction) was measured in grab and core samples of sediments from the Beaufort Sea and Eskimo Lakes, Northwest Territories, Canada. Very low rates (about 25 mg N/m/sup 2/.year) were detected in untreated sediments. Activity was markedly stimulated by the addition of glucose, sucrose, lactose, mannitol and malate but much less so by acetate; negligible activity was supported by N-acetylglucosamine. There was no consistent effect of the presence or absence of oxygen. Nitrogen fixation potentials in glucose-supplemented sediment samples showed large variation between stations, between samples from the same station and between depths within single cores down to 18 cm. Weathered Normal Wells crude oil, hexane, decane, dodecane and hexadecane had no effect, stimulatory or inhibitory, on nitrogen fixation or carbon dioxide evolution. 1,2,4-trimethylbenzene caused complete inhibition of nitrogen fixation but only partial inhibition of CO/sub 2/ evolution. There was no evidence of utilization of any of the hydrocarbons tested during periods of over 30 days under the experimental conditions employed.

  12. Uranium dioxide. Sintering test

    International Nuclear Information System (INIS)

    Anon.

    Description of a sintering method and of the equipment devoted to uranium dioxide powder caracterization and comparison between different samples. Determination of the curve giving specific volume versus pressure and micrographic examination of a pellet at medium pressure [fr

  13. [Effectiveness comparison of suspension fixation plus hinged external fixator and double plate internal fixation in treatment of type C humeral intercondylar fractures].

    Science.gov (United States)

    Zhang, Jian; Lin, Xu; Zhong, Zeli; Wu, Chao; Tan, Lun

    2017-07-01

    To compare the effectiveness of suspension fixation plus hinged external fixator with double plate internal fixation in the treatment of type C humeral intercondylar fractures. Between January 2014 and April 2016, 30 patients with type C (Association for the Study of Internal Fixation, AO/ASIF) humeral intercondylar fractures were treated. Kirschner wire suspension fixation plus hinged external fixator was used in 14 cases (group A), and double plate internal fixation in 16 cases (group B). There was no significant difference in gender, age, injury cause, disease duration, injury side, and type of fracture between 2 groups ( P >0.05). There was no significant difference in operation time and hospitalization stay between 2 groups ( P >0.05). But the intraoperative blood loss in group A was significantly less than that in group B ( P internal fixation removal, the intraoperative blood loss, and VAS score at 1 day and 3 days after operation in group A were significant better than those in group B ( P external fixator and double plate internal fixation for the treatment of type C humeral intercondylar fractures have ideal outcome in elbow function. But the suspension fixation plus hinged external fixator is better than double plate internal fixation in intraoperative blood loss, postoperative VAS score, and time of internal fixation removal.

  14. Global metabolic rewiring for improved CO2 fixation and chemical production in cyanobacteria

    Science.gov (United States)

    Kanno, Masahiro; Carroll, Austin L.; Atsumi, Shota

    2017-03-01

    Cyanobacteria have attracted much attention as hosts to recycle CO2 into valuable chemicals. Although cyanobacteria have been engineered to produce various compounds, production efficiencies are too low for commercialization. Here we engineer the carbon metabolism of Synechococcus elongatus PCC 7942 to improve glucose utilization, enhance CO2 fixation and increase chemical production. We introduce modifications in glycolytic pathways and the Calvin Benson cycle to increase carbon flux and redirect it towards carbon fixation. The engineered strain efficiently uses both CO2 and glucose, and produces 12.6 g l-1 of 2,3-butanediol with a rate of 1.1 g l-1 d-1 under continuous light conditions. Removal of native regulation enables carbon fixation and 2,3-butanediol production in the absence of light. This represents a significant step towards industrial viability and an excellent example of carbon metabolism plasticity.

  15. Fixation probability on clique-based graphs

    Science.gov (United States)

    Choi, Jeong-Ok; Yu, Unjong

    2018-02-01

    The fixation probability of a mutant in the evolutionary dynamics of Moran process is calculated by the Monte-Carlo method on a few families of clique-based graphs. It is shown that the complete suppression of fixation can be realized with the generalized clique-wheel graph in the limit of small wheel-clique ratio and infinite size. The family of clique-star is an amplifier, and clique-arms graph changes from amplifier to suppressor as the fitness of the mutant increases. We demonstrate that the overall structure of a graph can be more important to determine the fixation probability than the degree or the heat heterogeneity. The dependence of the fixation probability on the position of the first mutant is discussed.

  16. Fixation of Selenium by Clay Minerals and Iron Oxides

    DEFF Research Database (Denmark)

    Hamdy, A. A.; Nielsen, Gunnar Gissel

    1977-01-01

    In studying Se fixation, soil components capable of retaining Se were investigated. The importance of Fe hydrous oxides in the fixation of Se was established. The clay minerals common to soils, such as kaolinite, montmorillonite and vermiculite, all exhibited Se fixation, but greater fixation occ...

  17. Biomechanical Evaluation of Standard Versus Extended Proximal Fixation Olecranon Plates for Fixation of Olecranon Fractures.

    Science.gov (United States)

    Boden, Allison L; Daly, Charles A; Dalwadi, Poonam P; Boden, Stephanie A; Hutton, William C; Muppavarapu, Raghuveer C; Gottschalk, Michael B

    2018-01-01

    Small olecranon fractures present a significant challenge for fixation, which has resulted in development of plates with proximal extension. Olecranon-specific plates with proximal extensions are widely thought to offer superior fixation of small proximal fragments but have distinct disadvantages: larger dissection, increased hardware prominence, and the increased possibility of impingement. Previous biomechanical studies of olecranon fracture fixation have compared methods of fracture fixation, but to date there have been no studies defining olecranon plate fixation strength for standard versus extended olecranon plates. The purpose of this study is to evaluate the biomechanical utility of the extended plate for treatment of olecranon fractures. Sixteen matched pairs of fresh-frozen human cadaveric elbows were used. Of the 16, 8 matched pairs received a transverse osteotomy including 25% and 8 including 50% of the articular surface on the proximal fragment. One elbow from each pair was randomly assigned to a standard-length plate, and the other elbow in the pair received the extended-length plate, for fixation of the fracture. The ulnae were cyclically loaded and subsequently loaded to failure, with ultimate load, number of cycles, and gap formation recorded. There was no statistically significant difference between the standard and extended fixation plates in simple transverse fractures at either 25% or 50% from the proximal most portion of the articular surface of the olecranon. Standard fixation plates are sufficient for the fixation of small transverse fractures, but caution should be utilized particularly with comminution and nontransverse fracture patterns.

  18. Maxwellian Eye Fixation during Natural Scene Perception

    Directory of Open Access Journals (Sweden)

    Jean Duchesne

    2012-01-01

    Full Text Available When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell’s law for each participant and for each scene condition (normal or scrambled. The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes.

  19. Variable Nitrogen Fixation in Wild Populus.

    Directory of Open Access Journals (Sweden)

    Sharon L Doty

    Full Text Available The microbiome of plants is diverse, and like that of animals, is important for overall health and nutrient acquisition. In legumes and actinorhizal plants, a portion of essential nitrogen (N is obtained through symbiosis with nodule-inhabiting, N2-fixing microorganisms. However, a variety of non-nodulating plant species can also thrive in natural, low-N settings. Some of these species may rely on endophytes, microorganisms that live within plants, to fix N2 gas into usable forms. Here we report the first direct evidence of N2 fixation in the early successional wild tree, Populus trichocarpa, a non-leguminous tree, from its native riparian habitat. In order to measure N2 fixation, surface-sterilized cuttings of wild poplar were assayed using both 15N2 incorporation and the commonly used acetylene reduction assay. The 15N label was incorporated at high levels in a subset of cuttings, suggesting a high level of N-fixation. Similarly, acetylene was reduced to ethylene in some samples. The microbiota of the cuttings was highly variable, both in numbers of cultured bacteria and in genetic diversity. Our results indicated that associative N2-fixation occurred within wild poplar and that a non-uniformity in the distribution of endophytic bacteria may explain the variability in N-fixation activity. These results point to the need for molecular studies to decipher the required microbial consortia and conditions for effective endophytic N2-fixation in trees.

  20. Maxwellian Eye Fixation during Natural Scene Perception

    Science.gov (United States)

    Duchesne, Jean; Bouvier, Vincent; Guillemé, Julien; Coubard, Olivier A.

    2012-01-01

    When we explore a visual scene, our eyes make saccades to jump rapidly from one area to another and fixate regions of interest to extract useful information. While the role of fixation eye movements in vision has been widely studied, their random nature has been a hitherto neglected issue. Here we conducted two experiments to examine the Maxwellian nature of eye movements during fixation. In Experiment 1, eight participants were asked to perform free viewing of natural scenes displayed on a computer screen while their eye movements were recorded. For each participant, the probability density function (PDF) of eye movement amplitude during fixation obeyed the law established by Maxwell for describing molecule velocity in gas. Only the mean amplitude of eye movements varied with expertise, which was lower in experts than novice participants. In Experiment 2, two participants underwent fixed time, free viewing of natural scenes and of their scrambled version while their eye movements were recorded. Again, the PDF of eye movement amplitude during fixation obeyed Maxwell's law for each participant and for each scene condition (normal or scrambled). The results suggest that eye fixation during natural scene perception describes a random motion regardless of top-down or of bottom-up processes. PMID:23226987

  1. Strain-stress analysis of lower limb with applied fixator

    Directory of Open Access Journals (Sweden)

    Mrázek M.

    2010-07-01

    Full Text Available This paper compares physiological state of tibia before and after application of an external fixator. The fixator systems’ models but also model of tibia are loaded in the direction of body axis. The paper is focused on the examination of differences in stiffness before and after the application of fixation. Two types of axial external fixators are compared. Both fixators differ in their construction. The first fixator is two-frame and fixation rods are used for fixing the bone tissue (variant I. The second one is fixed into tibia with screws (variant II. We have found out that the two-frame external fixator has much bigger stiffness during limb fixation than the fixator with one body. Much higher deformations compared to physiological state of tibia occur in the variant II.

  2. Initial organic products of fixation of [13N]dinitrogen by root nodules of soybean (Glycine max)

    International Nuclear Information System (INIS)

    Meeks, J.C.; Wolk, C.P.; Schilling, N.; Shaffer, P.W.; Avissar, Y.; Chien, W.S.

    1978-01-01

    When detached soybean Glycine max (L.) Merr. cv. Hark, nodules assimilate ( 13 N)N 2 , the initial organic product of fixation is glutamine; glutamate becomes more highly radioactive than glutamine within 1 minute; 13 N in alanine becomes detectable at 1 minute of fixation and increases rapidly between 1 and 2 minutes. After 15 minutes of fixation, the major 13 N-labeled organic products in both detached and attached nodules are glutamate and alanine, plus, in the case of attached nodules, an unidentified substance, whereas ( 13 N)glutamine comprises only a small fraction of organic 13 N, and very little 13 N is detected in asparagine. The fixation of ( 13 N)N 2 into organic products was inhibited more than 99 percent by C 2 H 2 (10 percent, v/v). The results support the idea that the glutamine synthetase-glutamate synthase pathway is the primary route for assimilation of fixed nitrogen in soybean nodules

  3. Nitrogen fixation in trees - 1

    Energy Technology Data Exchange (ETDEWEB)

    Dobereiner, J.; Gauthier, D.L.; Diem, H.G.; Dommergues, Y.R.; Bonetti, R.; Oliveira, L.A.; Magalhaes, F.M.M.; Faria, S.M. de; Franco, A.A.; Menandro, M.S.

    1984-01-01

    Six papers are presented from the symposium. Dobereiner, J.; Nodulation and nitrogen fixation in leguminous trees, 83-90, (15 ref.), reviews studies on Brazilian species. Gauthier, D.L., Diem, H.G., Dommergues, Y.R., Tropical and subtropical actinorhizal plants, 119-136, (Refs. 50), reports on studies on Casuarinaceae. Bonetti, R., Oliveira, L.A., Magalhaes, F.M.M.; Rhizobium populations and occurrence of VA mycorrhizae in plantations of forest trees, 137-142, (Refs. 15), studies Amazonia stands of Cedrelinga catenaeformis, Calophyllum brasiliense, Dipteryx odorata, D. potiphylla, Carapa guianensis, Goupia glabra, Tabebuia serratifolia, Clarisia racemosa, Pithecellobium racemosum, Vouacapoua pallidior, Eperua bijuga, and Diplotropis species. Nodulation was observed in Cedrelinga catenaeformis and V. pallidior. Faria, S.M. de, Franco, A.A., Menandro, M.S., Jesus, R.M. de, Baitello, J.B.; Aguiar, O.T. de, Doebereiner, J; survey of nodulation in leguminous tree species native to southeastern Brazil, 143-153, (Refs. 7), reports on 119 species, with first reports of nodulation in the genera Bowdichia, Poecilanthe, Melanoxylon, Moldenhaurea (Moldenhawera), and Pseudosamanea. Gaiad, S., Carpanezzi, A.A.; Occurrence of Rhizobium in Leguminosae of silvicultural interest for south Brazil, 155-158, (Refs. 2). Nodulation is reported in Mimosa scabrella, Acacia mearnsii, A. longifolia various trinervis, Enterolobium contortisiliquum, and Erythrina falcata. Magalhaes, L.M.S., Blum, W.E.H., Nodulation and growth of Cedrelinga catanaeformis in experimental stands in the Manaus region - Amazonas, 159-164, (Refs. 5). Results indicate that C. catenaeformis can be used in degraded areas of very low soil fertility.

  4. From chemolithoautotrophs to electrolithoautotrophs: CO2 fixation by Fe(II)-oxidizing bacteria coupled with direct uptake of electrons from solid electron sources.

    Science.gov (United States)

    Ishii, Takumi; Kawaichi, Satoshi; Nakagawa, Hirotaka; Hashimoto, Kazuhito; Nakamura, Ryuhei

    2015-01-01

    At deep-sea vent systems, hydrothermal emissions rich in reductive chemicals replace solar energy as fuels to support microbial carbon assimilation. Until recently, all the microbial components at vent systems have been assumed to be fostered by the primary production of chemolithoautotrophs; however, both the laboratory and on-site studies demonstrated electrical current generation at vent systems and have suggested that a portion of microbial carbon assimilation is stimulated by the direct uptake of electrons from electrically conductive minerals. Here we show that chemolithoautotrophic Fe(II)-oxidizing bacterium, Acidithiobacillus ferrooxidans, switches the electron source for carbon assimilation from diffusible Fe(2+) ions to an electrode under the condition that electrical current is the only source of energy and electrons. Site-specific marking of a cytochrome aa3 complex (aa3 complex) and a cytochrome bc1 complex (bc1 complex) in viable cells demonstrated that the electrons taken directly from an electrode are used for O2 reduction via a down-hill pathway, which generates proton motive force that is used for pushing the electrons to NAD(+) through a bc1 complex. Activation of carbon dioxide fixation by a direct electron uptake was also confirmed by the clear potential dependency of cell growth. These results reveal a previously unknown bioenergetic versatility of Fe(II)-oxidizing bacteria to use solid electron sources and will help with understanding carbon assimilation of microbial components living in electronically conductive chimney habitats.

  5. Carbon dioxide and climate

    International Nuclear Information System (INIS)

    1991-10-01

    Global climate change is a serious environmental concern, and the US has developed ''An Action Agenda'' to deal with it. At the heart of the US effort is the US Global Change Research Program (USGCRP), which has been developed by the Committee on Earth and Environmental Sciences (CEES) of the Federal Coordinating Council for Sciences, Engineering, and Technology (FCCSET). The USGCRP will provide the scientific basis for sound policy making on the climate-change issue. The DOE contribution to the USGCRP is the Carbon Dioxide Research Program, which now places particular emphasis on the rapid improvement of the capability to predict global and regional climate change. DOE's Carbon Dioxide Research Program has been addressing the carbon dioxide-climate change connection for more than twelve years and has provided a solid scientific foundation for the USGCRP. The expansion of the DOE effort reflects the increased attention that the Department has placed on the issue and is reflected in the National Energy Strategy (NES) that was released in 1991. This Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1991 and gives a brief overview of objectives, organization, and accomplishments. The Environmental Sciences Division of the Office of Health and Environmental Research, Office of Energy Research supports a Carbon Dioxide Research Program to determine the scientific linkage between the rise of greenhouse gases in the atmosphere, especially carbon dioxide, and climate and vegetation change. One facet is the Core CO 2 Program, a pioneering program that DOE established more than 10 years ago to understand and predict the ways that fossil-fuel burning could affect atmospheric CO 2 concentration, global climate, and the Earth's biosphere. Major research areas are: global carbon cycle; climate detection and models of climate change; vegetation research; resource analysis; and, information and integration

  6. Nitrogen fixation in denitrified marine waters.

    Directory of Open Access Journals (Sweden)

    Camila Fernandez

    Full Text Available Nitrogen fixation is an essential process that biologically transforms atmospheric dinitrogen gas to ammonia, therefore compensating for nitrogen losses occurring via denitrification and anammox. Currently, inputs and losses of nitrogen to the ocean resulting from these processes are thought to be spatially separated: nitrogen fixation takes place primarily in open ocean environments (mainly through diazotrophic cyanobacteria, whereas nitrogen losses occur in oxygen-depleted intermediate waters and sediments (mostly via denitrifying and anammox bacteria. Here we report on rates of nitrogen fixation obtained during two oceanographic cruises in 2005 and 2007 in the eastern tropical South Pacific (ETSP, a region characterized by the presence of coastal upwelling and a major permanent oxygen minimum zone (OMZ. Our results show significant rates of nitrogen fixation in the water column; however, integrated rates from the surface down to 120 m varied by ∼30 fold between cruises (7.5±4.6 versus 190±82.3 µmol m(-2 d(-1. Moreover, rates were measured down to 400 m depth in 2007, indicating that the contribution to the integrated rates of the subsurface oxygen-deficient layer was ∼5 times higher (574±294 µmol m(-2 d(-1 than the oxic euphotic layer (48±68 µmol m(-2 d(-1. Concurrent molecular measurements detected the dinitrogenase reductase gene nifH in surface and subsurface waters. Phylogenetic analysis of the nifH sequences showed the presence of a diverse diazotrophic community at the time of the highest measured nitrogen fixation rates. Our results thus demonstrate the occurrence of nitrogen fixation in nutrient-rich coastal upwelling systems and, importantly, within the underlying OMZ. They also suggest that nitrogen fixation is a widespread process that can sporadically provide a supplementary source of fixed nitrogen in these regions.

  7. Nitrogen Fixation in Denitrified Marine Waters

    Science.gov (United States)

    Fernandez, Camila; Farías, Laura; Ulloa, Osvaldo

    2011-01-01

    Nitrogen fixation is an essential process that biologically transforms atmospheric dinitrogen gas to ammonia, therefore compensating for nitrogen losses occurring via denitrification and anammox. Currently, inputs and losses of nitrogen to the ocean resulting from these processes are thought to be spatially separated: nitrogen fixation takes place primarily in open ocean environments (mainly through diazotrophic cyanobacteria), whereas nitrogen losses occur in oxygen-depleted intermediate waters and sediments (mostly via denitrifying and anammox bacteria). Here we report on rates of nitrogen fixation obtained during two oceanographic cruises in 2005 and 2007 in the eastern tropical South Pacific (ETSP), a region characterized by the presence of coastal upwelling and a major permanent oxygen minimum zone (OMZ). Our results show significant rates of nitrogen fixation in the water column; however, integrated rates from the surface down to 120 m varied by ∼30 fold between cruises (7.5±4.6 versus 190±82.3 µmol m−2 d−1). Moreover, rates were measured down to 400 m depth in 2007, indicating that the contribution to the integrated rates of the subsurface oxygen-deficient layer was ∼5 times higher (574±294 µmol m−2 d−1) than the oxic euphotic layer (48±68 µmol m−2 d−1). Concurrent molecular measurements detected the dinitrogenase reductase gene nifH in surface and subsurface waters. Phylogenetic analysis of the nifH sequences showed the presence of a diverse diazotrophic community at the time of the highest measured nitrogen fixation rates. Our results thus demonstrate the occurrence of nitrogen fixation in nutrient-rich coastal upwelling systems and, importantly, within the underlying OMZ. They also suggest that nitrogen fixation is a widespread process that can sporadically provide a supplementary source of fixed nitrogen in these regions. PMID:21687726

  8. Deposition of carbon dioxide

    International Nuclear Information System (INIS)

    2001-01-01

    In Norway, there is currently a debate about whether or not to build gas power stations. To meet the possibility of reduced emission quotas for carbon dioxide in the future, current interest focuses on the incorporation of large-scale separation and deposition of carbon dioxide when such plants are planned. A group of experts concludes that this technology will become self-financing by means of environmental taxes. From the environmental point of view, taxes upon production are to be preferred over taxes on consumption

  9. Ocean Fertilization for Sequestration of Carbon Dioxide from the Atmosphere

    Science.gov (United States)

    Boyd, Philip W.

    The ocean is a major sink for both preindustrial and anthropogenic carbon dioxide. Both physically and biogeochemically driven pumps, termed the solubility and biological pump, respectively Fig.5.1) are responsible for the majority of carbon sequestration in the ocean's interior [1]. The solubility pump relies on ocean circulation - specifically the impact of cooling of the upper ocean at high latitudes both enhances the solubility of carbon dioxide and the density of the waters which sink to great depth (the so-called deepwater formation) and thereby sequester carbon in the form of dissolved inorganic carbon (Fig.5.1). The biological pump is driven by the availability of preformed plant macronutrients such as nitrate or phosphate which are taken up by phytoplankton during photosynthetic carbon fixation. A small but significant proportion of this fixed carbon sinks into the ocean's interior in the form of settling particles, and in order to maintain equilibrium carbon dioxide from the atmosphere is transferred across the air-sea interface into the ocean (the so-called carbon drawdown) thereby decreasing atmospheric carbon dioxide (Fig.5.1).Fig.5.1

  10. Iodide-Photocatalyzed Reduction of Carbon Dioxide to Formic Acid with Thiols and Hydrogen Sulfide.

    Science.gov (United States)

    Berton, Mateo; Mello, Rossella; González-Núñez, María Elena

    2016-12-20

    The photolysis of iodide anions promotes the reaction of carbon dioxide with hydrogen sulfide or thiols to quantitatively yield formic acid and sulfur or disulfides. The reaction proceeds in acetonitrile and aqueous solutions, at atmospheric pressure and room temperature by irradiation using a low-pressure mercury lamp. This transition-metal-free photocatalytic process for CO 2 capture coupled with H 2 S removal may have been relevant as a prebiotic carbon dioxide fixation. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Graft fixation in cruciate ligament reconstruction.

    Science.gov (United States)

    Brand, J; Weiler, A; Caborn, D N; Brown, C H; Johnson, D L

    2000-01-01

    Cruciate ligament reconstruction has progressed dramatically in the last 20 years. Anatomic placement of ligament substitutes has fostered rehabilitation efforts that stress immediate and full range of motion, immediate weightbearing, neuromuscular strength and coordination, and early return to athletic competition (3 months). This has placed extreme importance on secure graft fixation at the time of ligament reconstruction. Current ligament substitutes require a bony or soft tissue component to be fixed within a bone tunnel or on the periosteum at a distance from the normal ligament attachment site. Fixation devices have progressed from metal to biodegradable and from far to near-normal native ligament attachment sites. Ideally, the biomechanical properties of the entire graft construct would approach those of the native ligament and facilitate biologic incorporation of the graft. Fixation should be done at the normal anatomic attachment site of the native ligament (aperture fixation) and, over time, allow the biologic return of the histologic transition zone from ligament to fibrocartilage, to calcified fibrocartilage, to bone. The purpose of this article is to review current fixation devices and techniques in cruciate ligament surgery.

  12. External fixation of “intertrochanteric” fractures

    Science.gov (United States)

    Gani, Naseem ul; Kangoo, Khursheed Ahmed; Bashir, Arshad; Muzaffer, Rahil; Bhat, Mohammad Farooq; Farooq, Munir; Badoo, Abdul Rashid; Dar, Imtiyaz Hussian; Wani, Mudassir Maqbool

    2009-01-01

    In developing countries, due to limited availability of modern anesthesia and overcrowding of the hospitals with patients who need surgery, high-risk patients with “intertrochanteric” fractures remain unsuita ble for open reduction and internal fixation. The aim of this study was to analyze the results of external fixation of “intertrochanteric” fractures in high-risk geriatric patients in a developing country. The results of 62 ambulatory high-risk geriatric patients with a mean age of 70 years (range 58–90 years) with “intertrochanteric” fractures, in whom external fixation was performed, are reported. Eight patients died during follow-up due to medical causes unrelated to the surgical procedure. So only 54 patients were available for final assessment. Procedure is simple, performed under local anesthesia, requires less time for surgery and is associated with less blood loss. Good fixation and early ambulation was achieved in most of the patients. Average time to union was 14 weeks. Thirty-one patients developed superficial pin tract infection and 28 patients had average shortening of 15 mm due to impaction and varus angulation. Functional outcome was assessed using Judet's point system. Good to excellent results were achieved in 44 patients. This study demonstrated that external fixation of “intertrochantric” fractures performed under local anesthesia offers significant advantage in ambulatory high-risk geriatric patients especially in a developing country. PMID:21808680

  13. External fixation of “intertrochanteric” fractures

    Directory of Open Access Journals (Sweden)

    Naseem ul Gani

    2009-08-01

    Full Text Available In developing countries, due to limited availability of modern anesthesia and overcrowding of the hospitals with patients who need surgery, high-risk patients with “intertro-chanteric” fractures remain unsuitable for open reduction and internal fixation. The aim of this study was to analyze the results of external fixation of “intertro-chanteric” fractures in high-risk geriatric patients in a developing country. The results of 62 ambulatory high-risk geriatric patients with a mean age of 70 years (range 58-90 years with “intertrochanteric” fractures, in whom external fixation was performed, are reported. Eight patients died during follow-up due to medical causes unrelated to the surgical procedure. So only 54 patients were available for final assessment. Procedure is simple, performed under local anesthesia, requires less time for surgery and is associated with less blood loss. Good fixation and early ambulation was achieved in most of the patients. Average time to union was 14 weeks. Thirty-one patients developed superficial pin tract infection and 28 patients had average shortening of 15 mm due to impaction and varus angulation. Functional outcome was assessed using Judet’s point system. Good to excellent results were achieved in 44 patients. This study demonstrated that external fixation of “intertrochantric” fractures performed under local anesthesia offers significant advantage in ambulatory high-risk geriatric patients especially in a developing country.

  14. Does Carbon Dioxide Predict Temperature?

    OpenAIRE

    Mytty, Tuukka

    2013-01-01

    Does carbon dioxide predict temperature? No it does not, in the time period of 1880-2004 with the carbon dioxide and temperature data used in this thesis. According to the Inter Governmental Panel on Climate Change(IPCC) carbon dioxide is the most important factor in raising the global temperature. Therefore, it is reasonable to assume that carbon dioxide truly predicts temperature. Because this paper uses observational data it has to be kept in mind that no causality interpretation can be ma...

  15. Carbon Dioxide Sensor Technology.

    Science.gov (United States)

    1983-04-01

    second gas permeable membrane separates a compartment containing the non-aqueous " solvent dimethylsulfoxide , ( DMSO ), from the aqueous solution...compartment. In DMSO carbon dioxide can be irreversibly reduced electrochemically to * non-interfering products...current due to its reduction in the DMSO solution is proportional to the partial pressure of CO2 in the gas phase. Overall, the linear response and

  16. Carbon dioxide sensor

    Science.gov (United States)

    Dutta, Prabir K [Worthington, OH; Lee, Inhee [Columbus, OH; Akbar, Sheikh A [Hilliard, OH

    2011-11-15

    The present invention generally relates to carbon dioxide (CO.sub.2) sensors. In one embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor that incorporates lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3). In another embodiment, the present invention relates to a carbon dioxide (CO.sub.2) sensor has a reduced sensitivity to humidity due to a sensing electrode with a layered structure of lithium carbonate and barium carbonate. In still another embodiment, the present invention relates to a method of producing carbon dioxide (CO.sub.2) sensors having lithium phosphate (Li.sub.3PO.sub.4) as an electrolyte and sensing electrode comprising a combination of lithium carbonate (Li.sub.2CO.sub.3) and barium carbonate (BaCO.sub.3).

  17. Balancing atmospheric carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Goreau, T.J. (Discovery Bay Marine Laboratory, Univ. of the West Indies (JM))

    1990-01-01

    Rising carbon dioxide and global temperatures are causing increasing worldwide concern, and pressure towards an international law of the atmosphere is rapidly escalating, yet widespread misconceptions about the greenhouse effect's inevitability, time scale, and causes have inhibited effective consensus and action. Observations from Antarctic ice cores, Amazonian rain forests, and Carribean coral reefs suggest that the biological effects of climate change may be more severe than climate models predict. Efforts to limit emissions from fossil-fuel combustion alone are incapable of stabilizing levels of carbon dioxide in the atmosphere. Stabilizing atmospheric carbon dioxide requires coupled measures to balance sources and sinks of the gas, and will only be viable with large-scale investments in increased sustainable productivity on degraded tropical soils, and in long-term research on renewable energy and biomass product development in the developing countries. A mechanism is outlined which directly links fossil-fuel combustion sources of carbon dioxide to removal via increasing biotic productivity and storage. A preliminary cost-benefit analysis suggests that such measures are very affordable, costing far less than inaction. (With 88 refs.).

  18. Balancing atmospheric carbon dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Goreau, T J [Discovery Bay Marine Laboratory, Univ. of the West Indies (JM)

    1990-01-01

    Rising carbon dioxide and global temperatures are causing increasing worldwide concern, and pressure towards an international law of the atmosphere is rapidly escalating, yet widespread misconceptions about the greenhouse effect's inevitability, time scale, and causes have inhibited effective consensus and action. Observations from Antarctic ice cores, Amazonian rain forests, and Carribean coral reefs suggest that the biological effects of climate change may be more severe than climate models predict. Efforts to limit emissions from fossil-fuel combustion alone are incapable of stabilizing levels of carbon dioxide in the atmosphere. Stabilizing atmospheric carbon dioxide requires coupled measures to balance sources and sinks of the gas, and will only be viable with large-scale investments in increased sustainable productivity on degraded tropical soils, and in long-term research on renewable energy and biomass product development in the developing countries. A mechanism is outlined which directly links fossil-fuel combustion sources of carbon dioxide to removal via increasing biotic productivity and storage. A preliminary cost-benefit analysis suggests that such measures are very affordable, costing far less than inaction. (With 88 refs.).

  19. Evolution and Adaptation of Phytoplankton Photosynthetic Pathways to perturbations of the geological carbon system

    Science.gov (United States)

    Rickaby, R. E.; Young, J. N.; Hermoso, M.; Heureux, A.; McCLelland, H.; Lee, R.; Eason Hubbard, M.

    2012-12-01

    The ocean and atmosphere carbon system has varied greatly over geological history both in response to initial evolutionary innovation, and as a driver of adaptive change. Here we establish that positive selection in Rubisco, the most abundant enzyme on the Earth responsible for all photosynthetic carbon fixation, occurred early in Earth's history, and basal to the radiation of the modern marine algal groups. Our signals of positive selection appear to be triggered by changing intracellular concentrations of carbon dioxide (CO2) due to the emergence of carbon concentrating mechanisms between 1.56 and 0.41 Ba in response to declining atmospheric CO2 . We contend that, at least in terms of carbon, phytoplankton generally were well poised to manage subsequent abrupt carbon cycle perturbations. The physiological pathways for optimising carbon acquisition across a wide range of ambient carbon dioxide concentrations had already been established and were genetically widespread across open ocean phytoplankton groups. We will further investigate some case studies from the Mesozoic and Cenozoic abrupt carbon cycle excursions using isotopic tools to probe the community photosynthetic response and demonstrate the flexibility of phytoplankton photosynthesis in the face of major perturbations. In particular, an unprecedented resolution record across the Toarcian (Early Jurassic) carbon isotope excursion in the Paris Basin reveals a selection and evolution towards a community reliant solely on diffusive carbon dioxide supply for photosynthesis at the height of the excursion at 1500-2500 ppm CO2. The continued flourishing of the phytoplankton biological pump throughout this excursion was able to remove the excess carbon injected into the water column in less than 45 kyrs.

  20. Loads applied to fixations for chain stretching

    Energy Technology Data Exchange (ETDEWEB)

    Ahrens, K; Brychta, P

    1985-06-01

    The chains of scraper chain conveyors must be pre-stretched during standstill in order to compensate the elongations occurring during operation. They require frequent retensiening in order to meet the varying operational requirements. During tensioning, the chains are fixed in a point in the top run by means of fixation elements. The authors present a method for calculating the retaining force needed in the fixations. There are three different initial conditions of the chain before trensioning: Tensionsfree chain, pretensioned chain (stressed chain), slack chain. In all three cases, it is important to find out whether or nor the tensioning drive reaches full speed. The method of calculation is illustrated by the example of a scraper chain conveyor; it enables the establishment of rules for tensioning without damaging the chain and is a good basis for the dimensioning of new types of fixation elements.

  1. Biometric recognition via fixation density maps

    Science.gov (United States)

    Rigas, Ioannis; Komogortsev, Oleg V.

    2014-05-01

    This work introduces and evaluates a novel eye movement-driven biometric approach that employs eye fixation density maps for person identification. The proposed feature offers a dynamic representation of the biometric identity, storing rich information regarding the behavioral and physical eye movement characteristics of the individuals. The innate ability of fixation density maps to capture the spatial layout of the eye movements in conjunction with their probabilistic nature makes them a particularly suitable option as an eye movement biometrical trait in cases when free-viewing stimuli is presented. In order to demonstrate the effectiveness of the proposed approach, the method is evaluated on three different datasets containing a wide gamut of stimuli types, such as static images, video and text segments. The obtained results indicate a minimum EER (Equal Error Rate) of 18.3 %, revealing the perspectives on the utilization of fixation density maps as an enhancing biometrical cue during identification scenarios in dynamic visual environments.

  2. Dehydrogenation of Ethylbenzene with Carbon Dioxide as Soft Oxidant over Supported Vanadium-Antimony Oxide Catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Do Young; Vislovskiy, Vladislav P.; Yoo, Jin S.; Chang, Jong San [Korea Research Institute of Chemical Technology, Daejeon (Korea, Republic of); Park, Sang Eon [Inha University, Incheon (Korea, Republic of); Park, Min Seok [Mongolia International University, Ulaanbaatar (Mongolia)

    2005-11-15

    This work presents that carbon dioxide, which is a main contributor to the global warming effect, could be utilized as a selective oxidant in the oxidative dehydrogenation of ethylbenzene. The dehydrogenation of ethylbenzene over alumina-supported vanadium-antimony oxide catalyst has been studied under different atmospheres such as inert nitrogen, steam, oxygen or carbon dioxide as diluent or oxidant. Among them, the addition of carbon dioxide gave the highest styrene yield (up to 82%) and styrene selectivity (up to 97%) along with stable activity. Carbon dioxide could play a beneficial role of a selective oxidant in the improvement of the catalytic behavior through the oxidative pathway.

  3. Tricortical cervical inter-body screw fixation.

    Directory of Open Access Journals (Sweden)

    Goel A

    1997-01-01

    Full Text Available A new tricortical method of screw implantation for anterior cervical interbody plate fixation is described. The screws are placed obliquely such that they engage the anterior cortex of the body and traverse through the cortices adjoining the disc space. By this method the screws not only hold the plate firmly with a tricortical purchase, but by virtue of their course stabilize the two adjoining vertebral bodies by themselves. Sixteen patients were treated by this method. In three of these cases only tricortical screws without the metal plate were used for fixation. The advantages of the technique are discussed.

  4. Cosmetic arm lengthening with monorail fixator.

    Science.gov (United States)

    Agrawal, Hemendra Kumar; Singh, Balvinder; Garg, Mohit; Khatkar, Vipin; Batra, Sumit; Sharma, Vinod Kumar

    2015-01-01

    Upper limb length discrepancy is a rare occurrence. Humerus shortening may need specialized treatment to restore the functional and cosmetic status of upper limb. We report a case of humerus lengthening of 9 cm with a monorail external fixator and the result was observed during a 2-year follow-up. Humerus lengthening needs specialized focus as it is not only a cosmetic issue but also a functional demand. The monorail unilateral fixator is more functional and cosmetically acceptable, and thus becomes an effective treatment option.

  5. Carbon dioxide dangers demonstration model

    Science.gov (United States)

    Venezky, Dina; Wessells, Stephen

    2010-01-01

    Carbon dioxide is a dangerous volcanic gas. When carbon dioxide seeps from the ground, it normally mixes with the air and dissipates rapidly. However, because carbon dioxide gas is heavier than air, it can collect in snowbanks, depressions, and poorly ventilated enclosures posing a potential danger to people and other living things. In this experiment we show how carbon dioxide gas displaces oxygen as it collects in low-lying areas. When carbon dioxide, created by mixing vinegar and baking soda, is added to a bowl with candles of different heights, the flames are extinguished as if by magic.

  6. Transient improvements in fixational stability in strabismic amblyopes following bifoveal fixation and reduced interocular suppression.

    Science.gov (United States)

    Raveendran, Rajkumar Nallour; Babu, Raiju J; Hess, Robert F; Bobier, William R

    2014-03-01

    To test the hypothesis that fixational stability of the amblyopic eye in strabismics will improve when viewing provides both bifoveal fixation and reduced inter-ocular suppression by reducing the contrast to the fellow eye. Seven strabismic amblyopes (Age: 29.2 ± 9 years; five esotropes and two exotropes) showing clinical characteristics of central suppression were recruited. Interocular suppression was measured by a global motion task. For each participant, a balance point was determined which defined contrast levels for each eye where binocular combination was optimal (interocular suppression minimal). When the balance point could not be determined, this participant was excluded. Bifoveal fixation was established by ocular alignment using a haploscope. Participants dichoptically viewed similar targets (a cross of 2.3° surrounded by a square of 11.3°) at 40 cm. Target contrasts presented to each eye were either high contrast (100% to both eyes) or balanced contrast (attenuated contrast in the fellow fixing eye). Fixation stability was measured over a 5 min period and quantified using bivariate contour ellipse areas in four different binocular conditions; unaligned/high contrast, unaligned/balance point, aligned/high contrast and aligned/balance point. Fixation stability was also measured in six control subjects (Age: 25.3 ± 4 years). Bifoveal fixation in the strabismics was transient (58.15 ± 15.7 s). Accordingly, fixational stability was analysed over the first 30 s using repeated measures anova. Post hoc analysis revealed that for the amblyopic subjects, the fixational stability of the amblyopic eye was significantly improved in aligned/high contrast (p = 0.01) and aligned/balance point (p suppression. However, once initiated, bifoveal fixation is transient with the strabismic eye drifting away from foveal alignment, thereby increasing the angle of strabismus. © 2014 The Authors Ophthalmic & Physiological Optics © 2014 The College of Optometrists.

  7. Fixation Characteristics of Severe Amblyopia Subtypes: Which One is Worse?

    Science.gov (United States)

    Koylu, Mehmet Talay; Ozge, Gokhan; Kucukevcilioglu, Murat; Mutlu, Fatih Mehmet; Ceylan, Osman Melih; Akıncıoglu, Dorukcan; Ayyıldız, Onder

    2017-01-01

    To determine differences in macular sensitivity and fixation patterns in different subtypes of severe amblyopia. This case-control study enrolled a total of 73 male adults, including 18 with pure strabismic severe amblyopia, 19 with pure anisometropic severe amblyopia, 18 with mixed (strabismic plus anizometropic) severe amblyopia, and 18 healthy controls. MP-1 microperimetry was used to evaluate macular sensitivity, location of fixation, and stability of fixation. Mean macular sensitivity, stability of fixation, and location of fixation were significantly worse in all amblyopia subtypes when compared with healthy controls. Intergroup comparisons between amblyopia subtypes revealed that mean macular sensitivity, stability of fixation, and location of fixation were significantly worse in pure strabismic and mixed amblyopic eyes when compared with pure anisometropic amblyopic eyes. Strabismus seems to be a worse prognostic factor in severe amblyopia than anisometropia in terms of fixation characteristics and retinal sensitivity.

  8. Abundance and Distribution of Diagnostic Carbon Fixation Genes in a Deep-Sea Hydrothermal Gradient Ecosystem

    Science.gov (United States)

    Blumenfeld, H. N.; Kelley, D. S.; Girguis, P. R.; Schrenk, M. O.

    2010-12-01

    The walls of deep-sea hydrothermal vent chimneys sustain steep thermal and chemical gradients resulting from the mixing of hot (350°C+) hydrothermal fluids with cold, oxygenated seawater. The chemical disequilibrium generated from this process has the potential to drive numerous chemolithoautotrophic metabolisms, many of which have been demonstrated to be operative in microbial pure cultures. In addition to the well-known Calvin Cycle, at least five additional pathways have been discovered including the Reverse Tricarboxylic Acid Cycle (rTCA), the Reductive Acetyl-CoA pathway, and the 3-hydroxyproprionate pathway. Most of the newly discovered pathways have been found in thermophilic and hyperthermophilic Bacteria and Archaea, which are the well represented in microbial diversity studies of hydrothermal chimney walls. However, to date, little is known about the environmental controls that impact various carbon fixation pathways. The overlap of limited microbial diversity with distinct habitat conditions in hydrothermal chimney walls provides an ideal setting to explore these relationships. Hydrothermal chimney walls from multiple structures recovered from the Juan de Fuca Ridge in the northeastern Pacific were sub-sampled and analyzed using PCR-based assays. Earlier work showed elevated microbial abundances in the outer portions of mature chimney walls, with varying ratios of Archaea to Bacteria from the outer to inner portions of the chimneys. Common phylotypes identified in these regions included Epsilonproteobacteria, Gammaproteobacteria, and Desulfurococcales. Total genomic DNA was extracted from mineralogically distinct niches within these structures and queried for genes coding key regulatory enzymes for each of the well studied carbon fixation pathways. Preliminary results show the occurrence of genes representing rTCA cycle (aclB) and methyl coenzyme A reductase (mcrA) - a proxy for the Reductive Acetyl-CoA Pathway within interior portion of mature

  9. Sacroiliac screw fixation for tile B fractures.

    NARCIS (Netherlands)

    Bosch, E.W. van den; Zwienen, C.M. van; Hoek van Dijke, G.A.; Snijders, C.J.; Vugt, A.B. van

    2003-01-01

    BACKGROUND: The purpose of this comparative cadaveric study was to investigate whether the stability of partially unstable pelvic fractures can be improved by combining plate fixation of the symphysis with a posterior sacroiliac screw. METHODS: In six specimens, a Tile B1 (open-book) pelvic fracture

  10. Heterotrophic fixation of CO2 in soil

    Czech Academy of Sciences Publication Activity Database

    Šantrůčková, Hana; Bird, M. I.; Elhottová, Dana; Novák, Jaroslav; Picek, T.; Šimek, Miloslav; Tykva, Richard

    2005-01-01

    Roč. 49, č. 2 (2005), s. 218-225 ISSN 0095-3628 R&D Projects: GA ČR(CZ) GA206/02/1036; GA AV ČR(CZ) IAA6066901 Institutional research plan: CEZ:AV0Z60660521 Keywords : heterotrophic fixation * CO2 * soil Subject RIV: EH - Ecology, Behaviour Impact factor: 2.674, year: 2005

  11. Biodegradable interlocking nails for fracture fixation

    NARCIS (Netherlands)

    van der Elst, M.; Bramer, J. A.; Klein, C. P.; de Lange, E. S.; Patka, P.; Haarman, H. J.

    1998-01-01

    Serious problems such as stress shielding, allergic reactions, and corrosion are associated with the use of metallic fracture fixation devices in fractured long bones. Metal implants often are removed during a second retrieval operation after fracture healing has completed. A biocompatible implant

  12. Headspace analysis of foams and fixatives

    Energy Technology Data Exchange (ETDEWEB)

    Harper, Kyle [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Truong, Thanh-Tam [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Magwood, Leroy [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Peters, Brent [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Nicholson, James [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Washington, II, Aaron L. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-07-27

    In the process of decontaminating and decommissioning (D&D) older nuclear facilities, special precautions must be taken with removable or airborne contamination. One possible strategy utilizes foams and fixatives to affix these loose contaminants. Many foams and fixatives are already commercially available, either generically or sold specifically for D&D. However, due to a lack of revelant testing in a radioactive environment, additional verification is needed to confirm that these products not only affix contamination to their surfaces, but also will function in a D&D environment. Several significant safety factors, including flammability and worker safety, can be analyzed through the process of headspace analysis, a technique that analyzes the off gas formed before or during the curing process of the foam/fixative, usually using gas chromatography-mass spectrometry (GC-MS). This process focuses on the volatile components of a chemical, which move freely between the solid/liquid form within the sample and the gaseous form in the area above the sample (the headspace). Between possibly hot conditions in a D&D situation and heat created in a foaming reaction, the volatility of many chemicals can change, and thus different gasses can be released at different times throughout the reaction. This project focused on analysis of volatile chemicals involved in the process of using foams and fixatives to identify any potential hazardous or flammable compounds.

  13. Miniplate fixation of Le Fort I osteotomies.

    Science.gov (United States)

    Rosen, H M

    1986-12-01

    The use of rigid, internal, three-dimensional fixation using vitallium bone plates in 28 consecutive Le Fort I osteotomies is presented. A minimum follow-up period of 6 months was required for inclusion in this patient group. Maxillary movements included advancements (17), intrusions (9), lengthenings (5), and retrusions (2). The majority of maxillae were moved in more than one plane of space. Technical details, complications, and relapse potential are discussed. Advantages of rigid plate fixation include marked reductions in the length of intermaxillary fixation with light training elastics only. Immediate postoperative airway problems are thereby eliminated. Six months of follow-up would appear to indicate a low potential for osseous relapse when compared to wire osteosynthesis, regardless of the direction of maxillary movement. The major disadvantage is the decreased ability of postoperative orthodontics to move dento-osseous segments if skeletal occlusal disharmony persists postoperatively. For this reason, close attention to preoperative planning and operative technique is critical for the success of this fixation method.

  14. Large fluctuations and fixation in evolutionary games

    International Nuclear Information System (INIS)

    Assaf, Michael; Mobilia, Mauro

    2010-01-01

    We study large fluctuations in evolutionary games belonging to the coordination and anti-coordination classes. The dynamics of these games, modeling cooperation dilemmas, is characterized by a coexistence fixed point separating two absorbing states. We are particularly interested in the problem of fixation that refers to the possibility that a few mutants take over the entire population. Here, the fixation phenomenon is induced by large fluctuations and is investigated by a semiclassical WKB (Wentzel–Kramers–Brillouin) theory generalized to treat stochastic systems possessing multiple absorbing states. Importantly, this method allows us to analyze the combined influence of selection and random fluctuations on the evolutionary dynamics beyond the weak selection limit often considered in previous works. We accurately compute, including pre-exponential factors, the probability distribution function in the long-lived coexistence state and the mean fixation time necessary for a few mutants to take over the entire population in anti-coordination games, and also the fixation probability in the coordination class. Our analytical results compare excellently with extensive numerical simulations. Furthermore, we demonstrate that our treatment is superior to the Fokker–Planck approximation when the selection intensity is finite

  15. 15N in biological nitrogen fixation studies

    International Nuclear Information System (INIS)

    Faust, H.

    1986-05-01

    A bibliography with 298 references on the use of the stable nitrogen isotope 15 N in the research on the biological fixation of dinitrogen is presented. The literature pertaining to this bibliography covers the period from 1975 to the middle of 1985. (author)

  16. The effect of fixation on esterases

    DEFF Research Database (Denmark)

    Kirkeby, S; Moe, D

    1984-01-01

    The localization of reaction product for non-specific esterase from fresh and aldehyde treated glandular tissue was examined. The electrophoretical studies showed a selective inhibition of certain isoenzymes and a change in mobility of some bands caused by aldehyde fixation. In sections a granular...

  17. Osteomyelitis in burn patients requiring skeletal fixation

    NARCIS (Netherlands)

    Barret, JP; Desai, MH; Herndon, DN

    Deep and severe burns often present with the exposure of musculoskeletal structures and severe deformities. Skeletal fixation, suspension and/or traction are part of their comprehensive treatment. Several factors put burn patients at risk for osteomyelitis, osteosynthesis material being one of them.

  18. Locking plate fixation for proximal humerus fractures.

    LENUS (Irish Health Repository)

    Burke, Neil G

    2012-02-01

    Locking plates are increasingly used to surgically treat proximal humerus fractures. Knowledge of the bone quality of the proximal humerus is important. Studies have shown the medial and dorsal aspects of the proximal humeral head to have the highest bone strength, and this should be exploited by fixation techniques, particularly in elderly patients with osteoporosis. The goals of surgery for proximal humeral fractures should involve minimal soft tissue dissection and achieve anatomic reduction of the head complex with sufficient stability to allow for early shoulder mobilization. This article reviews various treatment options, in particular locking plate fixation. Locking plate fixation is associated with a high complication rate, such as avascular necrosis (7.9%), screw cutout (11.6%), and revision surgery (13.7%). These complications are frequently due to the varus deformation of the humeral head. Strategic screw placement in the humeral head would minimize the possibility of loss of fracture reduction and potential hardware complications. Locking plate fixation is a good surgical option for the management of proximal humerus fractures. Complications can be avoided by using better bone stock and by careful screw placement in the humeral head.

  19. Plasma catalysis for nitrogen fixation reactions

    NARCIS (Netherlands)

    Patil, B.S.; Wang, Q.; Hessel, V.; Lang, J.; Stankiewicz, A.; Stefanidis, G.

    2016-01-01

    The preferences for localized chemicals production and changing scenarios of renewable electricity cost gives a renewed boost to plasma-assisted valuable chemicals production. Especially, plasma-assisted nitrogen fixation for fertilizer production has the potential to largely change the energy

  20. Comparative study of fixation density maps

    NARCIS (Netherlands)

    Engelke, U.; Liu, H.; Wang, Junle; Callet, Le P.; Heynderickx, I.E.J.; Zepernick, H.-J.; Maeder, A.

    2013-01-01

    Fixation density maps (FDM) created from eye tracking experiments are widely used in image processing applications. The FDM are assumed to be reliable ground truths of human visual attention and as such, one expects a high similarity between FDM created in different laboratories. So far, no studies

  1. Methanation of Carbon Dioxide

    OpenAIRE

    Goodman, Daniel Jacob

    2013-01-01

    The emission of greenhouse gases into the atmosphere has been linked to global warming. Carbon dioxide's (CO2) one of the most abundant greenhouse gases. Natural gas, mainly methane, is the cleanest fossil fuel for electricity production helping meet the United States ever growing energy needs. The methanation of CO2 has the potential to address both of these problems if a catalyst can be developed that meets the activity, economic and environmental requirements to industrialize the process. ...

  2. Translaminar screw fixation in the lumbar spine: technique, indications, results

    OpenAIRE

    Grob, D.; Humke, T.

    1998-01-01

    Translaminar screw fixation of the lumbar spine represents a simple and effective technique for short segment fusion in the degenerative spine. Clinical experience with 173 patients who underwent translaminar screw fixation revealed a fusion rate of 94%. The indications for translaminar screw fixation as a primary fixation procedure are: segmental dysfunction, lumbar spinal stenosis with painful degenerative changes, segmental revision surgery after discectomies, and painful disc-related synd...

  3. Production of uranium dioxide

    International Nuclear Information System (INIS)

    Hart, J.E.; Shuck, D.L.; Lyon, W.L.

    1977-01-01

    A continuous, four stage fluidized bed process for converting uranium hexafluoride (UF 6 ) to ceramic-grade uranium dioxide (UO 2 ) powder suitable for use in the manufacture of fuel pellets for nuclear reactors is disclosed. The process comprises the steps of first reacting UF 6 with steam in a first fluidized bed, preferably at about 550 0 C, to form solid intermediate reaction products UO 2 F 2 , U 3 O 8 and an off-gas including hydrogen fluoride (HF). The solid intermediate reaction products are conveyed to a second fluidized bed reactor at which the mol fraction of HF is controlled at low levels in order to prevent the formation of uranium tetrafluoride (UF 4 ). The first intermediate reaction products are reacted in the second fluidized bed with steam and hydrogen at a temperature of about 630 0 C. The second intermediate reaction product including uranium dioxide (UO 2 ) is conveyed to a third fluidized bed reactor and reacted with additional steam and hydrogen at a temperature of about 650 0 C producing a reaction product consisting essentially of uranium dioxide having an oxygen-uranium ratio of about 2 and a low residual fluoride content. This product is then conveyed to a fourth fluidized bed wherein a mixture of air and preheated nitrogen is introduced in order to further reduce the fluoride content of the UO 2 and increase the oxygen-uranium ratio to about 2.25

  4. Characterization for Soil Fixation by Polyelectrolyte Complex

    International Nuclear Information System (INIS)

    Choi, Yong Suk; Kwon, Sang Woon; Yang, Heeman; Lee, Kune Woo; Seo, Bumkyoung; Moon, Jei Kwon

    2014-01-01

    According to report, the radioactivity bulk (approx. 95%) is localized within topsoil. Therefore soil surface on topsoil should be fixed to prevent the spreading of the contaminated soils with Cs-137 by wind and water erosion. Many methods have been developing for soil fixation to remove radioactive contaminants in soil and prevent to diffuse radioactive materials. Various materials have been also used as fixatives such as clays, molecular sieves, polymer, and petroleum based products. One of the methods is a soil fixation or solidification using polyelectrolyte. Polyelectrolytes have many ionic groups and make into the polyelectrolyte complex (PEC) due to electrostatic interaction of polyanion and polycation in an aqueous solution. It can be avoids using the chemical cross-linking agents, and reducing the possible toxicity and other undesirable effects of the reagents. PEC can fix soil particles by flocculation and formation of crust between soil. The method can also prevent a spread of radioactive material by floating on a soil surface. Recently, PEC used for the solidification of soil near the Fukushima nuclear power plant in Japan. The decontamination efficiency of the surface soils reached 90%, and dust release was effectively suppressed during the removal of surface soils. In this study, it was investigated the fixation of the soil by PEC to avoid the spread of the contamination in addition to the separation of soil and PEC. The physicochemical properties of polyelectrolyte complex solution and the stability of fixed soil by PEC were investigated. The mode of the addition is important to prepare the polyelectrolytes complex without PAA agglomerate. The concentration of salt in the polyelectrolyte complex solution is a very important parameter for the soil fixation

  5. Characterization for Soil Fixation by Polyelectrolyte Complex

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Suk; Kwon, Sang Woon; Yang, Heeman; Lee, Kune Woo; Seo, Bumkyoung; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    According to report, the radioactivity bulk (approx. 95%) is localized within topsoil. Therefore soil surface on topsoil should be fixed to prevent the spreading of the contaminated soils with Cs-137 by wind and water erosion. Many methods have been developing for soil fixation to remove radioactive contaminants in soil and prevent to diffuse radioactive materials. Various materials have been also used as fixatives such as clays, molecular sieves, polymer, and petroleum based products. One of the methods is a soil fixation or solidification using polyelectrolyte. Polyelectrolytes have many ionic groups and make into the polyelectrolyte complex (PEC) due to electrostatic interaction of polyanion and polycation in an aqueous solution. It can be avoids using the chemical cross-linking agents, and reducing the possible toxicity and other undesirable effects of the reagents. PEC can fix soil particles by flocculation and formation of crust between soil. The method can also prevent a spread of radioactive material by floating on a soil surface. Recently, PEC used for the solidification of soil near the Fukushima nuclear power plant in Japan. The decontamination efficiency of the surface soils reached 90%, and dust release was effectively suppressed during the removal of surface soils. In this study, it was investigated the fixation of the soil by PEC to avoid the spread of the contamination in addition to the separation of soil and PEC. The physicochemical properties of polyelectrolyte complex solution and the stability of fixed soil by PEC were investigated. The mode of the addition is important to prepare the polyelectrolytes complex without PAA agglomerate. The concentration of salt in the polyelectrolyte complex solution is a very important parameter for the soil fixation.

  6. External fixation combined with delayed internal fixation in treatment of tibial plateau fractures with dislocation.

    Science.gov (United States)

    Tao, Xingguang; Chen, Nong; Pan, Fugen; Cheng, Biao

    2017-10-01

    The aim of this study was to evaluate the clinical efficacy of external fixation, delayed open reduction, and internal fixation in treating tibial plateau fracture with dislocation.Clinical data of 34 patients diagnosed with tibial plateau fracture complicated with dislocation between January 2009 and May 2015 were retrospectively analyzed. Fifteen patients in group A underwent early calcaneus traction combined with open reduction and internal fixation and 19 in group B received early external fixation combined with delayed open reduction and internal fixation. Operation time, postoperative complication, bone healing time, knee joint range of motion, initial weight-bearing time, Rasmussen tibial plateau score, and knee function score (HSS) were statistically compared between 2 groups.The mean follow-up time was 18.6 months (range: 5-24 months). The mean operation time in group A was 96 minutes, significantly longer than 71 minutes in group B (P  .05). In group A, initial weight-bearing time in group A was (14.0 ± 3.6) weeks, significantly differing from (12.9 ± 2.8) weeks in group B (P  0.05). Rasmussen tibial plateau score in group A was slightly lower than that in group B (P > .05). The excellent rate of knee joint function in group A was 80% and 84.21% in group B (P > .05).External fixation combined with delayed open reduction and internal fixation is a safer and more efficacious therapy of tibial plateau fracture complicated with dislocation compared with early calcaneus traction and open reduction and internal fixation.

  7. [Treatment of pediatric distal femur fractures by external fixator combined with limited internal fixation].

    Science.gov (United States)

    Wei, Sheng-wang; Shi, Zhan-ying; Hu, Ju-zheng; Wu, Hao

    2016-03-01

    To discuss the clinical effects of external fixator combined with limited internal fixation in the treatment of pediatric distal femur fractures. From January 2008 to June 2014, 17 children of distal femur fractures were treated by external fixator combined with limited internal fixation. There were 12 males and 5 females, aged from 6 to 13 years old with an average of 10.2 years, ranged in the course of disease from 1 h to 2 d. Preoperative diagnoses were confirmed by X-ray films in all children. There were 11 patients with supracondylar fracture , and 6 patients with intercondylar comminuted fracture. According to AO/ASIF classification, 9 fractures were type A1, 5 cases were type A2,and 3 cases were type C1. The intraoperative and postoperative complications, postoperative radiological examination, lower limbs length and motion of knee joints were observed. Knee joint function was assessed by KSS score. All the patients were followed up from 6 to 38 months with an average of 24.4 months. No nerve or blood vessel injury was found. One case complicated with the external fixation loosening, 2 cases with the infection of pin hole and 3 cases with the leg length discrepancy. Knee joint mobility and length measurement (compared with the contralateral), the average limited inflexion was 10 degrees (0 degrees to 20 degrees), the average limited straight was 4 degrees (0 degrees to 10), the average varus or valgus angle was 3 degrees (0 degrees to 5 degrees). KSS of the injured side was (96.4 +/- 5.0) points at final follow-up, 16 cases got excellent results and 1 good. All fractures obtained healing and no epiphyseal closed early was found. External fixator combined with limited internal fixation has advantages of simple operation, reliable fixation, early functional exercise in treating pediatric distal femurs fractures.

  8. Comparison of skeletal stability after sagittal split ramus osteotomy among mono-cortical plate fixation, bi-cortical plate fixation, and hybrid fixation using absorbable plates and screws.

    Science.gov (United States)

    Ueki, Koichiro; Moroi, Akinori; Yoshizawa, Kunio; Hotta, Asami; Tsutsui, Takamitsu; Fukaya, Kenichi; Hiraide, Ryota; Takayama, Akihiro; Tsunoda, Tatsuta; Saito, Yuki

    2017-02-01

    The purpose of this study was to examine skeletal stability and plate breakage after sagittal split ramus osteotomy (SSRO) with the mono-cortical plate fixation, bi-cortical plate fixation, and hybrid fixation techniques using absorbable plates and screws. A total of 76 Japanese patients diagnosed with mandibular prognathism with and without maxillary deformity were divided into 3 groups randomly. A total of 28 patients underwent SSRO with mono-cortical plate fixation, 23 underwent SSRO with bi-cortical plate fixation, and 25 underwent SSRO with hybrid fixation. Skeletal stability and horizontal condylar angle were analyzed by axial, frontal, and lateral cephalograms from before the operation to 1 year postoperatively. Breakage of the plate and screws was observed by 3-dimensional computed tomography (3DCT) immediately after surgery and after 1 year. Although there was a significant difference between the mono-cortical plate fixation group and hybrid fixation group regarding right MeAg in T1 (P = 0.0488) and occlusal plane in T1 (P = 0.0346), there were no significant differences between the groups for the other measurements in each time interval. In 2 cases, namely, 6 sides in the mono-cortical plate fixation group, breakage of the absorbable plate was found by 3DCT. However, there was no breakage in the bi-cortical plate fixation group and hybrid fixation group. This study results suggested that there were no significant differences in the postoperative skeletal stability among the 3 groups, and bi-cortical fixation as well as hybrid fixation was a reliable and useful method to prevent plate breakage even if an absorbable material was used. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

  9. The cohesive energy of uranium dioxide and thorium dioxide

    International Nuclear Information System (INIS)

    Childs, B.G.

    1958-08-01

    Theoretical values have been calculated of the heats of formation of uranium dioxide and thorium dioxide on the assumption that the atomic binding forces in these solids are predominantly ionic in character. The good agreement found between the theoretical and observed values shows that the ionic model may, with care, be used in calculating the energies of defects in the uranium and thorium dioxide crystal structures. (author)

  10. Characterization of carbon dioxide concentrating chemolithotrophic bacterium Serratia sp. ISTD04 for production of biodiesel.

    Science.gov (United States)

    Kumar, Manish; Morya, Raj; Gnansounou, Edgard; Larroche, Christian; Thakur, Indu Shekhar

    2017-11-01

    Proteomics and metabolomics analysis has become a powerful tool for characterization of microbial ability for fixation of Carbon dioxide. Bacterial community of palaeoproterozoic metasediments was enriched in the shake flask culture in the presence of NaHCO 3 . One of the isolate showed resistance to NaHCO 3 (100mM) and was identified as Serratia sp. ISTD04 by 16S rRNA sequence analysis. Carbon dioxide fixing ability of the bacterium was established by carbonic anhydrase enzyme assay along with proteomic analysis by LC-MS/MS. In proteomic analysis 96 proteins were identified out of these 6 protein involved in carbon dioxide fixation, 11 in fatty acid metabolism, indicating the carbon dioxide fixing potency of bacterium along with production of biofuel. GC-MS analysis revealed that hydrocarbons and FAMEs produced by bacteria within the range of C 13 -C 24 and C 11 -C 19 respectively. Presence of 59% saturated and 41% unsaturated organic compounds, make it a better fuel composition. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Molybdenum dioxide-molybdenite roasting

    International Nuclear Information System (INIS)

    Sabacky, B.J.; Hepworth, M.T.

    1984-01-01

    A process is disclosed for roasting molybdenite concentrates directly to molybdenum dioxide. The process comprises establishing a roasting zone having a temperature of about 700 0 C. to about 800 0 C., introducing into the roasting zone particulate molybdenum dioxide and molybdenite in a weight ratio of at least about 2:1 along with an oxygen-containing gas in amount sufficient to oxidize the sulfur content of the molybdenite to molybdenum dioxide

  12. Gaze shifts and fixations dominate gaze behavior of walking cats

    Science.gov (United States)

    Rivers, Trevor J.; Sirota, Mikhail G.; Guttentag, Andrew I.; Ogorodnikov, Dmitri A.; Shah, Neet A.; Beloozerova, Irina N.

    2014-01-01

    Vision is important for locomotion in complex environments. How it is used to guide stepping is not well understood. We used an eye search coil technique combined with an active marker-based head recording system to characterize the gaze patterns of cats walking over terrains of different complexity: (1) on a flat surface in the dark when no visual information was available, (2) on the flat surface in light when visual information was available but not required, (3) along the highly structured but regular and familiar surface of a horizontal ladder, a task for which visual guidance of stepping was required, and (4) along a pathway cluttered with many small stones, an irregularly structured surface that was new each day. Three cats walked in a 2.5 m corridor, and 958 passages were analyzed. Gaze activity during the time when the gaze was directed at the walking surface was subdivided into four behaviors based on speed of gaze movement along the surface: gaze shift (fast movement), gaze fixation (no movement), constant gaze (movement at the body’s speed), and slow gaze (the remainder). We found that gaze shifts and fixations dominated the cats’ gaze behavior during all locomotor tasks, jointly occupying 62–84% of the time when the gaze was directed at the surface. As visual complexity of the surface and demand on visual guidance of stepping increased, cats spent more time looking at the surface, looked closer to them, and switched between gaze behaviors more often. During both visually guided locomotor tasks, gaze behaviors predominantly followed a repeated cycle of forward gaze shift followed by fixation. We call this behavior “gaze stepping”. Each gaze shift took gaze to a site approximately 75–80 cm in front of the cat, which the cat reached in 0.7–1.2 s and 1.1–1.6 strides. Constant gaze occupied only 5–21% of the time cats spent looking at the walking surface. PMID:24973656

  13. Titanium-based zeolitic imidazolate framework for chemical fixation of carbon dioxide

    Data.gov (United States)

    U.S. Environmental Protection Agency — A titanium-based zeolitic imidazolate framework (Ti-ZIF) with high surface area and porous morphology has been synthesized and its application as a recyclable...

  14. Carbon dioxide fixation by Calvin-Cycle enzymes improves ethanol yield in yeast

    NARCIS (Netherlands)

    Guadalupe-Medina, V.; Wisselink, H.W.; Luttik, M.A.H.; De Hulster, E.; Daran, J.M.; Pronk, J.T.; Van Maris, A.J.A.

    2013-01-01

    Background Redox-cofactor balancing constrains product yields in anaerobic fermentation processes. This challenge is exemplified by the formation of glycerol as major by-product in yeast-based bioethanol production, which is a direct consequence of the need to reoxidize excess NADH and causes a loss

  15. Fixation of carbon dioxide into dimethyl carbonate over titanium-based zeolitic thiophene-benzimidazolate framework

    Data.gov (United States)

    U.S. Environmental Protection Agency — A titanium-based zeolitic thiophene-benzimidazolate framework has been designed for the direct synthesis of dimethyl carbonate (DMC) from methanol and carbon...

  16. Nitrogen fixation improvement in Faidherbia albida

    International Nuclear Information System (INIS)

    Toure, O.; Dasilva, M.C.; Badji, S.; Dianda, M.; Ndoye, I.; Gueye, M.

    1998-01-01

    A greenhouse experiment investigated growth, N accumulation and N 2 fixation (using the 15 N-dilution method) by Faidherbia albida in comparison with three species of Acacia, with Parkia biglobosa and Tamarindus indica as non-fixing reference plants. Faidherbia albida was mediocre in comparison with A. seyel, therefore seven provenances of the former were examined in a second pot experiment to investigate within-species variability for the same performance components; a provenance from Kabrousse, Senegal, showed particular promise in terms of dry weight and N accumulation, and fixation of N. This promise was confirmed with a 15-month field experiment, but revealed that there is opportunity for further improvement in N 2 -fixing ability. Faidherbia albida is a slow-growing tree, therefore further field experiments with provenance Kabrousse should be longer term in scope. The data indicate that trenching of the 15 N-labelled area may not be necessary. (author)

  17. Intrasacral rod fixation for pediatric lumbopelvic fusion.

    Science.gov (United States)

    Ilharreborde, Brice; Mazda, Keyvan

    2014-07-01

    This paper reports the authors' 19 years experience with pediatric intrasacral rod fixation. After insertion of two cannulated screws in S1 with and an original template guiding them into the anterior third of the endplate, two short fusion rods were inserted into the sacrum according to Jackson's technique distally to S3. In neuromuscular scoliosis, pelvic obliquity was reduced by connecting the proximal and distal constructs, distraction or compression, and in situ rod bending. In children with high-grade spondylolisthesis, lumbosacral kyphosis was reduced by rotation of the sacrum and in situ bending. There were no direct neurological or vascular injuries. The main complication was infection (7%). No pseudarthrosis or significant loss of correction at the lumbosacral junction was observed during follow-up. Intrasacral rod fixation appears to be safe and reliable for lumbopelvic fusion in pediatric patients.

  18. Process for sequestering carbon dioxide and sulfur dioxide

    Science.gov (United States)

    Maroto-Valer, M Mercedes [State College, PA; Zhang, Yinzhi [State College, PA; Kuchta, Matthew E [State College, PA; Andresen, John M [State College, PA; Fauth, Dan J [Pittsburgh, PA

    2009-10-20

    A process for sequestering carbon dioxide, which includes reacting a silicate based material with an acid to form a suspension, and combining the suspension with carbon dioxide to create active carbonation of the silicate-based material, and thereafter producing a metal salt, silica and regenerating the acid in the liquid phase of the suspension.

  19. Scaphoid Fracture Fixation with an Acutrak? Screw

    OpenAIRE

    Loving, Vilert A.; Richardson, Michael L.

    2015-01-01

    We report a case of fixation of a scaphoid fracture using an Acutrak? screw. This screw is cannulated and headless, which allows it to be implanted below the surface of the bone. It uses the same concept of variable thread pitch as the Herbert screw, but unlike the Herbert screw, is fully threaded, with continuously varying pitch along its length. This variable pitch creates constant compression across a fracture as the screw is advanced, and gives the screw its unique appearance. This featur...

  20. High level waste fixation in cermet form

    International Nuclear Information System (INIS)

    Kobisk, E.H.; Aaron, W.S.; Quinby, T.C.; Ramey, D.W.

    1981-01-01

    Commercial and defense high level waste fixation in cermet form is being studied by personnel of the Isotopes Research Materials Laboratory, Solid State Division (ORNL). As a corollary to earlier research and development in forming high density ceramic and cermet rods, disks, and other shapes using separated isotopes, similar chemical and physical processing methods have been applied to synthetic and real waste fixation. Generally, experimental products resulting from this approach have shown physical and chemical characteristics which are deemed suitable for long-term storage, shipping, corrosive environments, high temperature environments, high waste loading, decay heat dissipation, and radiation damage. Although leach tests are not conclusive, what little comparative data are available show cermet to withstand hydrothermal conditions in water and brine solutions. The Soxhlet leach test, using radioactive cesium as a tracer, showed that leaching of cermet was about X100 less than that of 78 to 68 glass. Using essentially uncooled, untreated waste, cermet fixation was found to accommodate up to 75% waste loading and yet, because of its high thermal conductivity, a monolith of 0.6 m diameter and 3.3 m-length would have only a maximum centerline temperature of 29 K above the ambient value

  1. Nitrogen fixation in Red Sea seagrass meadows

    KAUST Repository

    Abdallah, Malak

    2017-05-01

    Seagrasses are key coastal ecosystems, providing many ecosystem services. Seagrasses increase biodiversity as they provide habitat for a large set of organisms. In addition, their structure provides hiding places to avoid predation. Seagrasses can grow in shallow marine coastal areas, but several factors regulate their growth and distribution. Seagrasses can uptake different kinds of organic and inorganic nutrients through their leaves and roots. Nitrogen and phosphorous are the most important nutrients for seagrass growth. Biological nitrogen fixation is the conversion of atmospheric nitrogen into ammonia by diazotrophic bacteria. This process provides a significant source of nitrogen for seagrass growth. The nitrogen fixation is controlled by the nif genes which are found in diazotrophs. The main goal of the project is to measure nitrogen fixation rates on seagrass sediments, in order to compare among various seagrass species from the Red Sea. Moreover, we will compare the fixing rates of the Vegetated areas with the bare sediments. This project will help to ascertain the role of nitrogen fixing bacteria in the development of seagrass meadows.

  2. [Complications of open reduction and internal fixation versus external fixation for unstable distal radius fractures: a meta-analysis].

    Science.gov (United States)

    Yang, Z; Yuan, Z Z; Ma, J X; Ma, X L

    2016-12-20

    Objective: To make a systematic assessment of the complications of open reduction and internal fixation versus external fixation for unstable distal radius fractures. Method: A computer-based online search of PubMed, ScienceDirect, EMBASE, BIOSIS, Springer and Cochrane Library were performed.The randomized and controlled trials of open reduction and internal fixation versus external fixation for unstable distal radius fractures were collected.The included trials were screened out strictly based on the criterion of inclusion and exclusion.The quality of included trials was evaluated.RevMan 5.0 was used for data analysis. Result: A total of 17 studies involving 1 402 patients were included.There were 687 patients with open reduction and internal fixation and 715 with external fixation.The results of Meta-analysis indicated that there were statistically significant differences with regard to the postoperatively total complications, infection, malunion, tendon rupture ( I 2 =8%, RR =0.77(95% CI 0.65-0.91, Z =3.10, P 0.05). Conclusion: Postoperative complications are present in both open reduction and internal fixation and external fixation.Compared with external fixation, open reduction and internal fixation is lower in total complications postoperatively, infection and malunion, but external fixation has lower tendon rupture incidence.

  3. Effectiveness of external fixator combined with T-plate internal fixation for the treatment of comminuted distal radius fractures.

    Science.gov (United States)

    Han, L R; Jin, C X; Yan, J; Han, S Z; He, X B; Yang, X F

    2015-03-31

    This study compared the efficacy between external fixator combined with palmar T-plate internal fixation and simple plate internal fixation for the treatment of comminuted distal radius fractures. A total of 61 patients classified as type C according to the AO/ASIF classification underwent surgery for comminuted distal radius fractures. There were 54 and 7 cases of closed and open fractures, respectively. Moreover, 19 patients received an external fixator combined with T-plate internal fixation, and 42 received simple plate internal fixation. All patients were treated successfully during 12-month postoperative follow-up. The follow-up results show that the palmar flexion and dorsiflexion of the wrist, radial height, and palmar angle were significantly better in those treated with the external fixator combined with T-plate compared to those treated with the simple plate only (P 0.05). Hence, the effectiveness of external fixator combined with T-plate internal fixation for the treatment of comminuted distal radius fractures was satisfactory. Patients sufficiently recovered wrist, forearm, and hand function. In conclusion, compared to the simple T-plate, the external fixator combined with T-plate internal fixation can reduce the possibility of the postoperative re-shifting of broken bones and keep the distraction of fractures to maintain radial height and prevent radial shortening.

  4. Comparison of screw fixation with elastic fixation methods in the treatment of syndesmosis injuries in ankle fractures.

    Science.gov (United States)

    Seyhan, Mustafa; Donmez, Ferdi; Mahirogullari, Mahir; Cakmak, Selami; Mutlu, Serhat; Guler, Olcay

    2015-07-01

    17 patients with ankle syndesmosic injury were treated with a 4.5mm single cortical screw fixation (passage of screw 4 cortices) and 15 patients were treated with single-level elastic fixation material. All patients were evaluated according to the AOFAS ankle and posterior foot scale at the third, sixth and twelfth months after the fixation. The ankle range of movement was recorded together with the healthy side. The Student's t test was used for statistical comparisons. No statistical significant difference was observed between the AOFAS scores (p>0.05). The range of dorsiflexion and plantar flexion motion of the elastic fixation group at the 6th and 12th months were significantly better compared to the screw fixation group (pankle syndesmosis injuries. The unnecessary need of a second surgical intervention for removal of the fixation material is another advantageous aspect of this method of fixation. Copyright © 2015. Published by Elsevier Ltd.

  5. [Extramedullary fixation combined with intramedullary fixation in the surgical reduction of sagittal mandibular condylar fractures].

    Science.gov (United States)

    Chuanjun, Chen; Xiaoyang, Chen; Jing, Chen

    2016-10-01

    This study aimed to evaluate the clinical effect of extramedullary fixation combined with intramedullary fixation during the surgical reduction of sagittal mandibular condylar fractures. Twenty-four sagittal fractures of the mandibular condyle in18 patients were fixed by two appliances: intramedullary with one long-screw osteosynthesis or Kirschner wire and extramedullary with one micro-plate. The radiologically-recorded post-operative stability-associated com-plications included the screw/micro-plate loosening, micro-plate twisting, micro-plate fractures, and fragment rotation. The occluding relations, the maximalinter-incisal distances upon mouth opening, and the mandibular deflection upon mouth opening were evaluated based on follow-up clinical examination. Postoperative panoramic X-ray and CT scans showed good repositioning of the fragment, with no redislocation or rotation, no screw/plate loosening, and no plate-twisting or fracture. Clinical examination showed that all patients regained normal mandibular movements, ideal occlusion, and normal maximal inter-incisal distances upon mouth opening. Extramedullary fixation combined with intramedullary fixation is highly recommended for sagittal condylar fractures because of the anti-rotation effect of the fragment and the reasonable place-ment of the fixation appliances.

  6. Carbon dioxide and climate

    Energy Technology Data Exchange (ETDEWEB)

    1990-10-01

    Scientific and public interest in greenhouse gases, climate warming, and global change virtually exploded in 1988. The Department's focused research on atmospheric CO{sub 2} contributed sound and timely scientific information to the many questions produced by the groundswell of interest and concern. Research projects summarized in this document provided the data base that made timely responses possible, and the contributions from participating scientists are genuinely appreciated. In the past year, the core CO{sub 2} research has continued to improve the scientific knowledge needed to project future atmospheric CO{sub 2} concentrations, to estimate climate sensitivity, and to assess the responses of vegetation to rising concentrations of CO{sub 2} and to climate change. The Carbon Dioxide Research Program's goal is to develop sound scientific information for policy formulation and governmental action in response to changes of atmospheric CO{sub 2}. The Program Summary describes projects funded by the Carbon Dioxide Research Program during FY 1990 and gives a brief overview of objectives, organization, and accomplishments.

  7. Quantitative analysis of an engineered CO2-fixing Escherichia coli reveals great potential of heterotrophic CO2 fixation.

    Science.gov (United States)

    Gong, Fuyu; Liu, Guoxia; Zhai, Xiaoyun; Zhou, Jie; Cai, Zhen; Li, Yin

    2015-01-01

    Production of fuels from the abundant and wasteful CO2 is a promising approach to reduce carbon emission and consumption of fossil fuels. Autotrophic microbes naturally assimilate CO2 using energy from light, hydrogen, and/or sulfur. However, their slow growth rates call for investigation of the possibility of heterotrophic CO2 fixation. Although preliminary research has suggested that CO2 fixation in heterotrophic microbes is feasible after incorporation of a CO2-fixing bypass into the central carbon metabolic pathway, it remains unclear how much and how efficient that CO2 can be fixed by a heterotrophic microbe. A simple metabolic flux index was developed to indicate the relative strength of the CO2-fixation flux. When two sequential enzymes of the cyanobacterial Calvin cycle were incorporated into an E. coli strain, the flux of the CO2-fixing bypass pathway accounts for 13 % of that of the central carbon metabolic pathway. The value was increased to 17 % when the carbonic anhydrase involved in the cyanobacterial carbon concentrating mechanism was introduced, indicating that low intracellular CO2 concentration is one limiting factor for CO2 fixation in E. coli. The engineered CO2-fixing E. coli with carbonic anhydrase was able to fix CO2 at a rate of 19.6 mg CO2 L(-1) h(-1) or the specific rate of 22.5 mg CO2 g DCW(-1) h(-1). This CO2-fixation rate is comparable with the reported rates of 14 autotrophic cyanobacteria and algae (10.5-147.0 mg CO2 L(-1) h(-1) or the specific rates of 3.5-23.7 mg CO2 g DCW(-1) h(-1)). The ability of CO2 fixation was created and improved in E. coli by incorporating partial cyanobacterial Calvin cycle and carbon concentrating mechanism, respectively. Quantitative analysis revealed that the CO2-fixation rate of this strain is comparable with that of the autotrophic cyanobacteria and algae, demonstrating great potential of heterotrophic CO2 fixation.

  8. Elucidation of rice rhizosphere metagenome in relation to methane and nitrogen metabolism under elevated carbon dioxide and temperature using whole genome metagenomic approach.

    Science.gov (United States)

    Bhattacharyya, P; Roy, K S; Das, M; Ray, S; Balachandar, D; Karthikeyan, S; Nayak, A K; Mohapatra, T

    2016-01-15

    Carbon (C) and nitrogen (N) mineralization is one of the key processes of biogeochemical cycling in terrestrial ecosystem in general and rice ecology in particular. Rice rhizosphere is a rich niche of microbial diversity influenced by change in atmospheric temperature and concentration of carbon dioxide (CO2). Structural changes in microbial communities in rhizosphere influence the nutrient cycling. In the present study, the bacterial diversity and population dynamics were studied under ambient CO2 (a-CO2) and elevated CO2+temperature (e-CO2T) in lowland rice rhizosphere using whole genome metagenomic approach. The whole genome metagenomic sequence data of lowland rice exhibited the dominance of bacterial communities including Proteobacteria, Firmicutes, Acidobacteria, Actinobacteria and Planctomycetes. Interestingly, four genera related to methane production namely, Methanobacterium, Methanosphaera, Methanothermus and Methanothermococcus were absent in a-CO2 but noticed under e-CO2T. The acetoclastic pathway was found as the predominant pathway for methanogenesis, whereas, the serine pathway was found as the principal metabolic pathway for CH4 oxidation in lowland rice. The abundances of reads of enzymes in the acetoclastic methanogenesis pathway and serine pathways of methanotrophy were much higher in e-CO2T (328 and 182, respectively) as compared with a-CO2 (118 and 98, respectively). Rice rhizosphere showed higher structural diversities and functional activities in relation to N metabolism involving nitrogen fixation, assimilatory and dissimilatory nitrate reduction and denitrification under e-CO2T than that of a-CO2. Among the three pathways of N metabolism, dissimilarity pathways were predominant in lowland rice rhizosphere and more so under e-CO2T. Consequently, under e-CO2T, CH4 emission, microbial biomass nitrogen (MBN) and dehydrogenase activities were 45%, 20% and 35% higher than a-CO2, respectively. Holistically, a high bacterial diversity and

  9. Fixation of displaced subcapital femoral fractures. Compression screw fixation versus double divergent pins.

    Science.gov (United States)

    Christie, J; Howie, C R; Armour, P C

    1988-03-01

    One hundred and twenty-seven consecutive patients with displaced subcapital fractures of the femoral neck (Garden Grade III or IV) all under 80 years of age and independently mobile, were randomly allocated to fixation with either double divergent pins or a single sliding screw-plate device. The incidence of non-union and infection in the sliding screw-plate group was significantly higher, and we believe that when internal fixation is considered appropriate multiple pinning should be used. Mobility after treatment was disappointing in about half of the patients, and we feel that internal fixation can only be justified in patients who are physiologically well preserved and who maintain a high level of activity.

  10. Fusion Surgery Required for Recurrent Pediatric Atlantoaxial Rotatory Fixation after Failure of Temporary Fixation with Instrumentation

    Directory of Open Access Journals (Sweden)

    Yoshiyuki Matsuyama

    2017-01-01

    Full Text Available In cases of chronic irreducible and recurrent unstable atlantoaxial rotatory fixation (AARF, closed reduction and its maintenance are often unsuccessful, requiring surgical treatment. The purpose of the present report is to describe a rare case of pediatric AARF that required multiple treatments. A 6-year-old boy was diagnosed as having type 2 AARF. After conservative treatment, the patient was treated with temporary fixation surgery (C1-C2 Magerl without a bone graft in consideration of motion preservation after screw removal. AARF recurred after the screw removal and required fusion surgery (Magerl–Brooks with an iliac bone graft. Ultimately, bone union was achieved and the screws were removed 11 months after the surgery. We recommend surgeons be cautious when choosing temporary fixation surgery for AARF in small children. Further investigation is needed to determine the optimal time before screw removal.

  11. Results of application of external fixation with different types of fixators

    Directory of Open Access Journals (Sweden)

    Grubor Predrag

    2012-01-01

    Full Text Available Introduction. Extra-focal or external fixation is the method of fracture fixation through the healthy part of the bone using pins or wires. Objective. The aim was to determine which external splints (Ortofix, Mitković, Charnley and Ilizarov had the best biomechanical properties in primary stabilization of spiral, transverse and commutative bone fractures. Methods. To determine the investigation methodology of biomechanical characteristics of the external fixator we used mathematical and computer simulator (software, juvidur physical model and clinical examination. Results. Values of advancing fragments in millimetres obtained by the study of mathematical and computer simulator (software: Charnley - 0.080 mm, Mitković M 20 - 0.785 mm, Ilizarov - 2.245 mm and Ortofix - 1.400 mm. In testing the juvidur model the following values were obtained: the external fixator Mitković M20 - 1.380 mm, Ortofix - 1.470 mm, Ilizarov - 2.410 mm, and Charnley - 2.510 mm. Clinical research of biomechanical characteristics of the effect of vertical force yielded the following results: Mitković M20 - 0.89 mm, Ortofix - 0.14 mm, Charnley - 0.80 mm and Ilizarov - 1.23 mm. Conclusion. When determining the total number of the stability test splints under the effect of vertical force (compression and force effect in antero-posterior, later-lateral plane of cross, spiral and comminuted long bone fractures, the best unified biomechanical stability was shown by the following external fixators: firstly, Mitković M20 (0.93mm, secondly, Charnley fixator (1.14 mm, thirdly, Ortofix (1.22 mm, and fourthly, Ilizarov (1.60 mm.

  12. Uranium dioxide electrolysis

    Science.gov (United States)

    Willit, James L [Batavia, IL; Ackerman, John P [Prescott, AZ; Williamson, Mark A [Naperville, IL

    2009-12-29

    This is a single stage process for treating spent nuclear fuel from light water reactors. The spent nuclear fuel, uranium oxide, UO.sub.2, is added to a solution of UCl.sub.4 dissolved in molten LiCl. A carbon anode and a metallic cathode is positioned in the molten salt bath. A power source is connected to the electrodes and a voltage greater than or equal to 1.3 volts is applied to the bath. At the anode, the carbon is oxidized to form carbon dioxide and uranium chloride. At the cathode, uranium is electroplated. The uranium chloride at the cathode reacts with more uranium oxide to continue the reaction. The process may also be used with other transuranic oxides and rare earth metal oxides.

  13. Uranium dioxide pellets

    International Nuclear Information System (INIS)

    Zawidzki, T.W.

    1982-01-01

    A process for the preparation of a sintered, high density, large crystal grain size uranium dioxide pellet is described which involves: (i) reacting a uranyl nitrate of formula UO 2 (NO 3 ) 2 .6H 2 O with a sulphur source, at a temperature of from about 300 deg. C to provide a sulphur-containing uranium trioxide; (ii) reacting the thus-obtained modified uranium trioxide with ammonium nitrate to form an insoluble sulphur-containing ammonium uranate; (iii) neutralizing the thus-formed slurry with ammonium hydroxide to precipitate out as an insoluble ammonium uranate the remaining dissolved uranium; (iv) recovering the thus-formed precipitates in a dry state; (v) reducing the dry precipitate to UO 2 , and forming it into 'green' pellets; and (vi) sintering the pellets in a hydrogen atmosphere at an elevated temperature

  14. Forecasting carbon dioxide emissions.

    Science.gov (United States)

    Zhao, Xiaobing; Du, Ding

    2015-09-01

    This study extends the literature on forecasting carbon dioxide (CO2) emissions by applying the reduced-form econometrics approach of Schmalensee et al. (1998) to a more recent sample period, the post-1997 period. Using the post-1997 period is motivated by the observation that the strengthening pace of global climate policy may have been accelerated since 1997. Based on our parameter estimates, we project 25% reduction in CO2 emissions by 2050 according to an economic and population growth scenario that is more consistent with recent global trends. Our forecasts are conservative due to that we do not have sufficient data to fully take into account recent developments in the global economy. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Uranium dioxide calcining apparatus

    International Nuclear Information System (INIS)

    Cole, E.A.; Peterson, R.S.

    1978-01-01

    This invention relates to an improved continuous calcining apparatus for consistently and controllably producing from calcinable reactive solid compounds of uranium, such as ammonium diuranate, uranium dioxide (UO 2 ) having an oxygen to uranium ratio of less than 2.2. The apparatus comprises means at the outlet end of a calciner kiln for receiving hot UO 2 , means for cooling the UO 2 to a temperature of below 100 deg C and conveying the cooled UO 2 to storage or to subsequent UO 2 processing apparatus where it finally comes into contact with air, the means for receiving cooling and conveying being sealed to the outlet end of the calciner and being maintained full of UO 2 and so operable as to exclude atmospheric oxygen from coming into contact with any UO 2 which is at elevated temperatures where it would readily oxidize, without the use of extra hydrogen gas in said means. (author)

  16. Management and follow up of tibial plateau fractures by ′T′ clamp external fixator and limited internal fixation

    Directory of Open Access Journals (Sweden)

    Thimmegowda M

    2005-01-01

    Full Text Available Background: Tibial plateau fractures are difficult to treat especially when soft tissue is compromised by open reduction and internal fixation. Many methods have be1en tried in the past to manage these cases of which external fixation were shown to be effective as they limit the soft tissue and wound complications. Methods: Complex tibial plateau fractures of sixteen patients were treated by closed reduction, fixation of articular fragments by screws and application of unilateral external fixator. The external fixator was kept in place till fracture united clinically and radiologically. The patients were followed up for at least one year to assess the function of the knee joint Results: The average duration of external fixation was 13 weeks. All the fractures healed. Pin track infection (five patients and instability (six patients of the knee were encountered with this procedure. The average duration of follow up was 62 weeks. The mean range of motion was 1250 arc. The IOWA knee score averaged 90.3 points. Conclusions: External fixation with limited internal fixation may be effective in the management of complex tibial plateau fractures which requires further support from studies with large sample size. ′T′ clamp external fixation with limited Internal fixation is the procedure of choice when alignment, stability, early mobilisation is required in a soft tissue compromised tibial plateau fractures.

  17. Improving Saliency Models by Predicting Human Fixation Patches

    KAUST Repository

    Dubey, Rachit

    2015-04-16

    There is growing interest in studying the Human Visual System (HVS) to supplement and improve the performance of computer vision tasks. A major challenge for current visual saliency models is predicting saliency in cluttered scenes (i.e. high false positive rate). In this paper, we propose a fixation patch detector that predicts image patches that contain human fixations with high probability. Our proposed model detects sparse fixation patches with an accuracy of 84 % and eliminates non-fixation patches with an accuracy of 84 % demonstrating that low-level image features can indeed be used to short-list and identify human fixation patches. We then show how these detected fixation patches can be used as saliency priors for popular saliency models, thus, reducing false positives while maintaining true positives. Extensive experimental results show that our proposed approach allows state-of-the-art saliency methods to achieve better prediction performance on benchmark datasets.

  18. Improving Saliency Models by Predicting Human Fixation Patches

    KAUST Repository

    Dubey, Rachit; Dave, Akshat; Ghanem, Bernard

    2015-01-01

    There is growing interest in studying the Human Visual System (HVS) to supplement and improve the performance of computer vision tasks. A major challenge for current visual saliency models is predicting saliency in cluttered scenes (i.e. high false positive rate). In this paper, we propose a fixation patch detector that predicts image patches that contain human fixations with high probability. Our proposed model detects sparse fixation patches with an accuracy of 84 % and eliminates non-fixation patches with an accuracy of 84 % demonstrating that low-level image features can indeed be used to short-list and identify human fixation patches. We then show how these detected fixation patches can be used as saliency priors for popular saliency models, thus, reducing false positives while maintaining true positives. Extensive experimental results show that our proposed approach allows state-of-the-art saliency methods to achieve better prediction performance on benchmark datasets.

  19. Bilateral Laparoscopic Totally Extraperitoneal Repair Without Mesh Fixation

    OpenAIRE

    Dehal, Ahmed; Woodward, Brandon; Johna, Samir; Yamanishi, Frank

    2014-01-01

    Background and Objectives: Mesh fixation during laparoscopic totally extraperitoneal repair is thought to be necessary to prevent recurrence. However, mesh fixation may increase postoperative chronic pain. This study aimed to describe the experience of a single surgeon at our institution performing this operation. Methods: We performed a retrospective review of the medical records of all patients who underwent bilateral laparoscopic totally extraperitoneal repair without mesh fixation for ing...

  20. Application of monorail fixator for femoral gap nonunion

    Directory of Open Access Journals (Sweden)

    Agrawal Hemendra Kumar

    2014-07-01

    Full Text Available 【Abstract】Difficult femoral nonunion takes account of infective nonunion and aseptic gap nonunion. Limb length discrepancy and nonunion need to be tackled simultaneously. Conventionally Ilizarov ring fixator is in vogue but it has some limitations. To overcome these, monorail fixator is an effective alternative. Persistent good results can be obtained if we can get a perfect anatomical alignment and good regeneration. Key words: Femur; Ilizarov technique; External fixators

  1. Carbon dioxide and future climate

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, J M

    1977-03-01

    The addition of carbon dioxide to the atmosphere due to burning fossil fuel is discussed. The release rate of carbon dioxide has been growing since at least 1950 at an average rate of 4.3% per year. If all known fossil fuel reserves in the world are consumed, a total of between 5 and 14 times the present amount of carbon dioxide in the atmosphere will be released. The oceans would then be unlikely to withdraw the proportion of perhaps 40% which they are believed to have withdrawn up to the present. The increase in the atmosphere would be in excess of 3 times or conceivably ten times the present amount. If the reserves are used up within a few hundred years, more than half the excess carbon dioxide would remain in the atmosphere after a thousand years. The ''greenhouse'' effect of carbon dioxide is explained. The simulation with numerical models of the effects of carbon dioxide on atmospheric radiation fluxes is discussed. An estimated increase in the average annual temperature of the earth of 2.4 to 2.9C is given for doubling the carbon dioxide content; also a 7% increase in global average precipitation. The effect of increasing carbon dioxide on global mean temperature is viewed in the perspective of the glacial-interglacial cycles. The warming effect of carbon dioxide may induce a ''super-interglacial'' on the present interglacial which is expected to decline toward a new ice age in the next several thousand years. Finally it is proposed that it may be necessary to phase out the use of fossil fuels before all the knowledge is acquired which would necessitate such an action.

  2. Rib Fracture Fixation: Indications and Outcomes.

    Science.gov (United States)

    Senekjian, Lara; Nirula, Raminder

    2017-01-01

    Rib fractures are a frequently identified injury in the trauma population. Not only are multiple rib fractures painful, but they are associated with an increased risk of adverse outcomes. Pneumonia in particular can be devastating, especially to an elderly patient, but other complications such as prolonged ventilation and increased intensive care and hospital durations of stay have a negative impact on the patient. Computed tomography scan is the best modality to diagnosis rib fractures but the treatment of fractures is still evolving. Currently patient care involves a multidisciplinary approach that includes pain control, aggressive pulmonary therapy, and possibly surgical fixation. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Nitrogen fixation on a coral reef

    Energy Technology Data Exchange (ETDEWEB)

    Mague, T.H.; Holm-Hansen, O.

    1975-06-01

    Benthic, heterocystous blue-green algae (genera Calothrix, Hormothamnion and Nostoc) from Eniwetok Atoll were found to reduce acetylene at rapid rates. Slight acetylene reduction was associated with samples of Rhizoclonium (Chlorophyceae) and Oscillatoria (a cyanophyte lacking heterocysts), but this may have been due to contamination by epiphytes. There was virtually no acetylene reduction by phytoplankton, and nutrient enrichment experiments failed to selectively increase the numbers or activity of N/sub 2/-fixing algae in surface water samples. The Nostoc required light for acetylene reduction. Nitrogen fixation by this species could have supplied up to 11 ..mu..g N/cm/sup 2//day to the ecosystem. (auth)

  4. Distal fingertip replantation without skeletal fixation.

    Science.gov (United States)

    Sabapathy, S Raja; Venkatramani, Hari; Bharathi, R Ravindra; Sebastin, Sandeep J

    2005-01-01

    The replantation of fingertip amputation (through the nail bed) requires repair of the artery and vein on the palmar side. These structures are present in different planes, with the artery being deeper and the veins superficial. The authors believe that vascular repair in such cases is facilitated by stabilization of the amputated part by nail-bed repair alone. This provides a certain degree of flexibility, which allows for easier placement of clamps in the limited space available. Although Kirschner wires were not used for bony fixation, bony union was achieved in all five cases in which this technique was used.

  5. Overcoming design fixation through education and creativity methods

    DEFF Research Database (Denmark)

    Howard, Thomas J.; Maier, Anja; Onarheim, Balder

    2013-01-01

    . The first intervention consisted of educating each team on the phenomena and effects of design fixation. The results showed that this intervention reduced the number of fixation elements in comparison to the control group (p=0.025). The second intervention involved using Dix et als' (2006) 'Bad Ideas...... of ideas produced per group and the groups' fixation ratios, adding to the quantity breads novelty debate. Finally, the study also provided further evidence of the hypothesis by Agogué et al (2011) that example solutions constructed from restrictive partitions have a greater fixation affect....

  6. A "footprint" of plant carbon fixation cycle functions during the development of a heterotrophic fungus.

    Science.gov (United States)

    Lyu, Xueliang; Shen, Cuicui; Xie, Jiatao; Fu, Yanping; Jiang, Daohong; Hu, Zijin; Tang, Lihua; Tang, Liguang; Ding, Feng; Li, Kunfei; Wu, Song; Hu, Yanping; Luo, Lilian; Li, Yuanhao; Wang, Qihua; Li, Guoqing; Cheng, Jiasen

    2015-08-11

    Carbon fixation pathway of plants (CFPP) in photosynthesis converts solar energy to biomass, bio-products and biofuel. Intriguingly, a large number of heterotrophic fungi also possess enzymes functionally associated with CFPP, raising the questions about their roles in fungal development and in evolution. Here, we report on the presence of 17 CFPP associated enzymes (ten in Calvin-Benson-Basham reductive pentose phosphate pathway and seven in C4-dicarboxylic acid cycle) in the genome of Sclerotinia sclerotiorum, a heterotrophic phytopathogenic fungus, and only two unique enzymes: ribulose-1, 5-bisphosphate carboxylase-oxygenase (Rubisco) and phosphoribulokinase (PRK) were absent. This data suggested an incomplete CFPP-like pathway (CLP) in fungi. Functional profile analysis demonstrated that the activity of the incomplete CLP was dramatically regulated during different developmental stages of S. sclerotiorum. Subsequent experiments confirmed that many of them were essential to the virulence and/or sclerotial formation. Most of the CLP associated genes are conserved in fungi. Phylogenetic analysis showed that many of them have undergone gene duplication, gene acquisition or loss and functional diversification in evolutionary history. These findings showed an evolutionary links in the carbon fixation processes of autotrophs and heterotrophs and implicated the functions of related genes were in course of continuous change in different organisms in evolution.

  7. Acute carbon dioxide avoidance in Caenorhabditis elegans.

    Science.gov (United States)

    Hallem, Elissa A; Sternberg, Paul W

    2008-06-10

    Carbon dioxide is produced as a by-product of cellular respiration by all aerobic organisms and thus serves for many animals as an important indicator of food, mates, and predators. However, whether free-living terrestrial nematodes such as Caenorhabditis elegans respond to CO2 was unclear. We have demonstrated that adult C. elegans display an acute avoidance response upon exposure to CO2 that is characterized by the cessation of forward movement and the rapid initiation of backward movement. This response is mediated by a cGMP signaling pathway that includes the cGMP-gated heteromeric channel TAX-2/TAX-4. CO2 avoidance is modulated by multiple signaling molecules, including the neuropeptide Y receptor NPR-1 and the calcineurin subunits TAX-6 and CNB-1. Nutritional status also modulates CO2 responsiveness via the insulin and TGFbeta signaling pathways. CO2 response is mediated by a neural circuit that includes the BAG neurons, a pair of sensory neurons of previously unknown function. TAX-2/TAX-4 function in the BAG neurons to mediate acute CO2 avoidance. Our results demonstrate that C. elegans senses and responds to CO2 using multiple signaling pathways and a neural network that includes the BAG neurons and that this response is modulated by the physiological state of the worm.

  8. Summary report of working group I CO{sub 2} capture, fixation/utilization, and disposal

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1993-12-31

    The topics of our working group were divided into four key areas: CO{sub 2} Capture, Utilization/Fixation, Ocean Disposal, and Land Disposal. Fourteen presentations were made as follows: CO{sub 2} Capture: Toshikatsu Hakuta (Japan) and Rod Judkins, Bruce St. John, and Alan Wolsky (US). Utilization/Fixation: Hironori Arakawa, Yasuo Asada, and Takashi lbusuki (Japan) and Ed Lipinsky (US). Ocean Disposal: Yuji Shindo (Japan) and Eric Adams, Gerard Nihous, and Wheeler North (US). Land Disposal: Shoichi Tanaka (Japan) and Roger Bailey (US/Canada). Co-chairs for this working group were Toshikatsu Hakuta (Japan) and Howard Herzog (US). This document contains only a summary outline of research needs in the area of CO{sub 2} capture and sequestration. It should be used in conjunction with other assessments made in this area. For the U.S., a DOE report entitled A Research Needs Assessment for the Capture, Utilization and Disposal of Carbon Dioxide from Fossil Fuel-Fired Power Plants will be forthcoming in 1993.

  9. Geminal phosphorus/aluminum-based frustrated Lewis pairs: C-H versus C≡C activation and CO2 fixation

    NARCIS (Netherlands)

    Appelt, C.; Westenberg, H.; Bertini, F.; Ehlers, A.W.; Slootweg, J.C.; Lammertsma, K.; Uhl, W.

    2011-01-01

    Catch it! Geminal phosphorus/aluminum-based frustrated Lewis pairs (FLPs) are easily obtained by hydroalumination of alkynylphosphines. These FLPs can activate terminal acetylenes by two competitive pathways, which were analyzed by DFT calculations, and they can bind carbon dioxide reversibly.

  10. Achievement report of projects in fiscal 2000 for measures on technologies to fix and utilize effectively carbon dioxide. Development of program system technologies to fix and utilize effectively carbon dioxide - researches on key technologies (Developing technology to fix carbon dioxide electrochemically); 2000 nendo program hoshiki nisanka tanso koteika yuko riyo gijutsu kaihatsu (kiban gijutsu kenkyu) seika hokokusho (kokaiyo). Nisanka tanso no denki kagakuteki koteika gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-03-01

    With an objective to prevent global warming, research and development has been made on a carbon dioxide fixation technology using electrochemical means. This paper summarizes the achievements in fiscal 2000. In the research of a technology to return carbon dioxide to hydrocarbon such as methane electrochemically utilizing the high concentration carbon dioxide-methanol system, basic studies were performed on electrolytic reduction of CO2 using a methanol solvent system, and experimental studies were executed on high-speed reduction of carbon dioxide using gas diffusion electrodes. In the basic property experiment on diamond electrodes, high carbon dioxide reduction activity was obtained by having copper carried in the diamond electrode. In the CO2 electrolytic reduction experiment on three-phase interface using a copper net electrode, CO, ethylene, and methane were produced, while the electrode has retained the activity for an extended period of time, and the CO2 conversion rate reached about 66%. In structuring an electrochemical carbon dioxide fixation system, specifications for the CO2 electrolytic reduction equipment were determined, design, manufacturing, and electrode materials were selected, supporting electrolytes were discussed, and the entire system flow and liquid resistance were discussed. (NEDO)

  11. Percutaneous anterior C1/2 transarticular screw fixation: salvage of failed percutaneous odontoid screw fixation for odontoid fracture

    OpenAIRE

    Wu, Ai-Min; Jin, Hai-Ming; Lin, Zhong-Ke; Chi, Yong-Long; Wang, Xiang-Yang

    2017-01-01

    Background The objective of this study is to investigate the outcomes and safety of using percutaneous anterior C1/2 transarticular screw fixation as a salvage technique for odontoid fracture if percutaneous odontoid screw fixation fails. Methods Fifteen in 108 odontoid fracture patients (planned to be treated by percutaneous anterior odontoid screw fixation) were failed to introduce satisfactory odontoid screw trajectory. To salvage this problem, we chose the percutaneous anterior C1/2 trans...

  12. Carbon Dioxide Emission Pathways Avoiding Dangerous Ocean Impacts

    OpenAIRE

    Kvale, K.; Zickfeld, K.; Bruckner, T.; Meissner, K. J.; Tanaka, K.; Weaver, A. J.

    2012-01-01

    Anthropogenic emissions of greenhouse gases could lead to undesirable effects on oceans in coming centuries. Drawing on recommendations published by the German Advisory Council on Global Change, levels of unacceptable global marine change (so-called guardrails) are defined in terms of global mean temperature, sea level rise, and ocean acidification. A global-mean climate model [the Aggregated Carbon Cycle, Atmospheric Chemistry and Climate Model (ACC2)] is coupled with an economic module [tak...

  13. Fiscal 1997 R and D project on industrial science and technology under a consignment from NEDO. R and D of the synthesis and processing of advanced biomaterials (fixation and effective utilization of carbon dioxide using peptides); 1997 nendo Shin energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku. Senshin bio zairyo no sosei kako gijutsu no kenkyu kaihatsu (peptide oyo nisanka tanso koteika yuko riyo gijutsu) seika hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    In fiscal 1997, study was made on formation of peptides with a biogenic function and molecular recognition function, and peptide materials. The existing automatic design technique of peptides including non-natural amino acids was applied to design of complementary peptides of proteins with known structures to optimize a development technique of ligand. Practical function of peptides as advanced receptor ligand was verified by applying the existing conformation control technique to stable holding of peptide active conformation. Creation of bio-materials, and development of preparation technology of bio-substrates and materializing technology of functional molecular materials were carried out. To construct an electron transfer system by self- organized body of peptides formed on a substrate, a peptide molecular device was prepared and verified using linkers. To use peptides as photoelectron functional molecule, metallized peptide with main helix structure was prepared. The possibility of molecular materials with a fixation function of CO2 was examined. A high-sensitivity bio-sensor was also mentioned. 75 refs., 130 figs., 25 tabs.

  14. Extraction of Uranium Using Nitrogen Dioxide and Carbon Dioxide for Spent Fuel Reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Kayo Sawada; Daisuke Hirabayashi; Youichi Enokida [EcoTopia Science Institute, Nagoya University, Nagoya, 464-8603 (Japan)

    2008-07-01

    For the reprocessing of spent nuclear fuels, a new method to extract actinides from spent fuel using highly compressed gases, nitrogen dioxide and carbon dioxide was proposed. Uranium extraction from broken pieces, whose average grain size was 5 mm, of uranium dioxide pellet with nitrogen dioxide and carbon dioxide was demonstrated in the present study. (authors)

  15. EXTERNAL FIXATION OF METACARPAL AND PHALANGAL FRACTURES

    Directory of Open Access Journals (Sweden)

    Krunoslav Margić

    2001-11-01

    Full Text Available Background. In past three years we have used smallexternal fixator in the treatment of: 18 closed fractures of metacarpalbones, 15 phalangeal fractures, four dislocated fracturesof MCP and five of PIP joint, ten arthrodesis, five replantations/revascularisations, two pathological fractures, and infew post-traumatic infection of bones and joints.Results. Results were graded as excellent (completely normalfunction, very good (15° deficit of total ROM, good (30° deficitof total ROM; can flex the fingers to the palm, and poor.Excellent result was obtained in the treatment of all 18 metacarpalfractures. The final results in the treatment of 12 closedfragmentated fractures of phalanges were as follows: excellent3, very good 2, good 2 and five poor results (three patientsin this group have fallen on their hands causing refractureand reoperation. Three of four fractures of MCP joint andfour of five fractures involving PIP joint have good mobility.In eight of ten patients arthrodeses are stable and withoutpain. In two cases pathological fractures were first stabilizedand than the tumor was evacuated and grafted with minimaldissection; booth have good results.Conclusion. Author suggests that, in selected cases, with applicationof small external fixator reasonable good results can beobtained.

  16. Biomechanics of lumbar cortical screw-rod fixation versus pedicle screw-rod fixation with and without interbody support.

    Science.gov (United States)

    Perez-Orribo, Luis; Kalb, Samuel; Reyes, Phillip M; Chang, Steve W; Crawford, Neil R

    2013-04-15

    Seven different combinations of posterior screw fixation, with or without interbody support, were compared in vitro using nondestructive flexibility tests. To study the biomechanical behavior of a new cortical screw (CS) fixation construct relative to the traditional pedicle screw (PS) construct. The CS is an alternative to the PS for posterior fixation of the lumbar spine. The CS trajectory is more sagittally and cranially oriented than the PS, being anchored in the pars interarticularis. Like PS fixation, CS fixation uses interconnecting rods fastened with top-locking connectors. Stability after bilateral CS fixation was compared with stability after bilateral PS fixation in the setting of intact disc and with direct lateral interbody fixation (DLIF) or transforaminal lateral interbody fixation (TLIF) support. Standard nondestructive flexibility tests were performed in cadaveric lumbar specimens, allowing non-paired comparisons of specific conditions from 28 specimens (4 groups of 7) within a larger experiment of multiple hardware configurations. Condition tested and group from which results originated were as follows: (1) intact (all groups); (2) with L3-L4 bilateral PS-rods (group 1); (3) with bilateral CS-rods (group 2); (4) with DLIF (group 3); (5) with DLIF + CS-rods (group 4); (6) with DLIF + PS-rods (group 3); (7) with TLIF + CS-rods (group 2), and (8) with TLIF + PS-rods (group 2). To assess spinal stability, the mean range of motion, lax zone, and stiff zone at L3-L4 were compared during flexion-extension, lateral bending, and axial rotation. With intact disc, stability was equivalent after PS-rod and CS-rod fixation, except that PS-rod fixation was stiffer during axial rotation. With DLIF support, there was no significant difference in stability between PS-rod and CS-rod fixation. With TLIF support, PS-rod fixation was stiffer than CS-rod fixation during lateral bending. Bilateral CS-rod fixation provided about the same stability in cadaveric specimens

  17. Reducing carbon dioxide to products

    Science.gov (United States)

    Cole, Emily Barton; Sivasankar, Narayanappa; Parajuli, Rishi; Keets, Kate A

    2014-09-30

    A method reducing carbon dioxide to one or more products may include steps (A) to (C). Step (A) may bubble said carbon dioxide into a solution of an electrolyte and a catalyst in a divided electrochemical cell. The divided electrochemical cell may include an anode in a first cell compartment and a cathode in a second cell compartment. The cathode may reduce said carbon dioxide into said products. Step (B) may adjust one or more of (a) a cathode material, (b) a surface morphology of said cathode, (c) said electrolyte, (d) a manner in which said carbon dioxide is bubbled, (e), a pH level of said solution, and (f) an electrical potential of said divided electrochemical cell, to vary at least one of (i) which of said products is produced and (ii) a faradaic yield of said products. Step (C) may separate said products from said solution.

  18. Internal Versus External Fixation of Charcot Midfoot Deformity Realignment.

    Science.gov (United States)

    Lee, Daniel J; Schaffer, Joseph; Chen, Tien; Oh, Irvin

    2016-07-01

    Internal and external fixation techniques have been described for realignment and arthrodesis of Charcot midfoot deformity. There currently is no consensus on the optimal method of surgical reconstruction. This systematic review compared the clinical results of surgical realignment with internal and external fixation, specifically in regard to return to functional ambulation, ulcer occurrence, nonunion, extremity amputation, unplanned further surgery, deep infection, wound healing problems, peri- or intraoperative fractures, and total cases with any complication. A search of multiple databases for all relevant articles published from January 1, 1990, to March 22, 2014, was performed. A logistic regression model evaluated each of the outcomes and its association with the type of fixation method. The odds of returning to functional ambulation were 25% higher for internal fixation (odds ratio [OR], 1.259). Internal fixation had a 42% reduced rate of ulcer occurrence (OR, 0.578). External fixation was 8 times more likely to develop radiographic nonunion than internal fixation (OR, 8.2). Internal fixation resulted in a 1.5-fold increase in extremity amputation (OR, 1.488), a 2-fold increase in deep infection (OR, 2.068), a 3.4-fold increase in wound healing complications (OR, 3.405), and a 1.5-fold increase in the total number of cases experiencing any complication (OR, 1.525). This was associated with a 20% increase in the need for unplanned further surgery with internal fixation (OR, 1.221). Although internal fixation may decrease the risk of nonunion and increase return to functional ambulation, it had a higher rate of overall complications than external fixation for realignment and arthrodesis of Charcot midfoot deformity. [Orthopedics. 2016; 39(4):e595-e601.]. Copyright 2016, SLACK Incorporated.

  19. Method for carbon dioxide sequestration

    Science.gov (United States)

    Wang, Yifeng; Bryan, Charles R.; Dewers, Thomas; Heath, Jason E.

    2017-12-05

    A method for geo-sequestration of a carbon dioxide includes selection of a target water-laden geological formation with low-permeability interbeds, providing an injection well into the formation and injecting supercritical carbon dioxide (SC-CO.sub.2) and water or bine into the injection well under conditions of temperature, pressure and density selected to cause the fluid to enter the formation and splinter and/or form immobilized ganglia within the formation.

  20. Recuperative supercritical carbon dioxide cycle

    Science.gov (United States)

    Sonwane, Chandrashekhar; Sprouse, Kenneth M; Subbaraman, Ganesan; O'Connor, George M; Johnson, Gregory A

    2014-11-18

    A power plant includes a closed loop, supercritical carbon dioxide system (CLS-CO.sub.2 system). The CLS-CO.sub.2 system includes a turbine-generator and a high temperature recuperator (HTR) that is arranged to receive expanded carbon dioxide from the turbine-generator. The HTR includes a plurality of heat exchangers that define respective heat exchange areas. At least two of the heat exchangers have different heat exchange areas.

  1. STUDY ON SPANNING EXTERNAL FIXATORS FOR PERIARTICULAR OPEN FRACTURES

    Directory of Open Access Journals (Sweden)

    Prasanth Maddila

    2017-04-01

    Full Text Available BACKGROUND Open fractures which occur close to any fracture need immobilisation for the soft tissues to heal. Some open fractures are even fixed with provisional fixations to maintain the alignment of the fractures. The provisional fixation needs to be augmented with external support, which can be given by spanning external fixators across a joint. MATERIALS AND METHODS Our study consists of 38 open fractures of the lower limbs, which are of Gustilo-Anderson’s type IIIB, an MT4 of AO-ASIF soft tissue injury classification essentially requiring open wound management as well as fracture fixation. Wound lavage and debridements are carried out till the soft tissues show granulations. The position in which joint is immobilised is functional and with access to open wound for dressings and inspection without any displacement of the fracture as well as creeping granulation tissue. RESULTS All the cases in our study are maintained with functional position till soft tissue cover is achieved and provisional fixation is done with definitive fixation after soft tissue cover with skin grafting. CONCLUSION Spanning external fixators are useful in maintaining functional positions as well as augmenting the provisional fixation of the compound fractures.

  2. Sacroiliac screw fixation: A mini review of surgical technique

    Directory of Open Access Journals (Sweden)

    Hernando Raphael Alvis-Miranda

    2014-01-01

    Full Text Available The sacral percutaneous fixation has many advantages but can be associated with a significant exposure to X-ray radiation. Currently, sacroiliac screw fixation represents the only minimally invasive technique to stabilize the posterior pelvic ring. It is a technique that should be used by experienced surgeons. We present a practical review of important aspects of this technique.

  3. Customizable rigid head fixation for infants: technical note.

    Science.gov (United States)

    Udayakumaran, Suhas; Onyia, Chiazor U

    2016-01-01

    The need and advantages of rigid fixation of the head in cranial surgeries are well documented (Berryhill et al., Otolaryngol Head Neck Surg 121:269-273, 1999). Head fixation for neurosurgical procedures in infants and in early years has been a challenge and is fraught with risk. Despite the fact that pediatric pins are designed, rigid head fixation involving direct application of pins to the head of infants and slightly older children is still generally not safe (Agrawal and Steinbok, Childs Nerv Syst 22:1473-1474, 2006). Yet, there are some surgeries in which some form of rigid fixation is required (Agrawal and Steinbok, Childs Nerv Syst 22:1473-1474, 2006). We describe a simple technique to achieve rigid fixation of the head in infants for neurosurgical procedures. This involves applying a head band made of Plaster of Paris (POP) around the head and then applying the fixation pins of the fixation frame directly on to the POP. We have used this technique of head fixation successfully for infants with no complications.

  4. Biomechanical analysis of titanium fixation plates and screws in ...

    African Journals Online (AJOL)

    Conclusions: It was concluded that the use of double 4-hole straight plates provided the sufficient stability on the osteotomy site when compared with the other rigid fixation methods used in this study. Key words: Bone plates, bone screws, finite element analysis, jaw fixation techniques, mandible, mandibular osteotomy ...

  5. Indications and outcome of Open Reduction and Internal Fixation of ...

    African Journals Online (AJOL)

    Background: Open reduction and internal fixation (ORIF) is a well-established surgical treatment of fractures worldwide. However, the indications and modes of stabilization of long bone fractures vary and are evolving .The general trend now is towards fixation with locked intramedullary nail (i.m nail) rather than plate and ...

  6. Predicting Eye Fixations on Complex Visual Stimuli Using Local Symmetry.

    Science.gov (United States)

    Kootstra, Gert; de Boer, Bart; Schomaker, Lambert R B

    2011-03-01

    Most bottom-up models that predict human eye fixations are based on contrast features. The saliency model of Itti, Koch and Niebur is an example of such contrast-saliency models. Although the model has been successfully compared to human eye fixations, we show that it lacks preciseness in the prediction of fixations on mirror-symmetrical forms. The contrast model gives high response at the borders, whereas human observers consistently look at the symmetrical center of these forms. We propose a saliency model that predicts eye fixations using local mirror symmetry. To test the model, we performed an eye-tracking experiment with participants viewing complex photographic images and compared the data with our symmetry model and the contrast model. The results show that our symmetry model predicts human eye fixations significantly better on a wide variety of images including many that are not selected for their symmetrical content. Moreover, our results show that especially early fixations are on highly symmetrical areas of the images. We conclude that symmetry is a strong predictor of human eye fixations and that it can be used as a predictor of the order of fixation.

  7. Femoral fractures : indications an[d] biomechanics of external fixation

    NARCIS (Netherlands)

    A.H. Broekhuizen (Tom); B. van Linge

    1988-01-01

    textabstractInternal fixation can be carried out in various ways. For femoral shaft fractures, an (interlocking) nail is becoming increasingly popular, instead of open realignment of the fracture. External fixation, which has become a generally accepted method of treating fractures of the lower

  8. Application of monorail fixator for femoral gap nonunion.

    Science.gov (United States)

    Agrawal, Hemendra-Kumar; Jaiman, Ashish; Khatkar, Vipin; Sharma, Vinod-Kumar

    2014-01-01

    Difficult femoral nonunion takes account of infective nonunion and aseptic gap nonunion. Limb length discrepancy and nonunion need to be tackled simultaneously. Conventionally Ilizarov ring fixator is in vogue but it has some limitations. To overcome these, monorail fixator is an effective alternative. Persistent good results can be obtained if we can get a perfect anatomical alignment and good regeneration.

  9. Predicting Eye Fixations on Complex Visual Stimuli Using Local Symmetry

    NARCIS (Netherlands)

    Kootstra, Geert; de Boer, Bart; Schomaker, Lambertus

    Most bottom-up models that predict human eye fixations are based on contrast features. The saliency model of Itti, Koch and Niebur is an example of such contrast-saliency models. Although the model has been successfully compared to human eye fixations, we show that it lacks preciseness in the

  10. Predicting eye fixations on complex visual stimuli using local symmetry

    NARCIS (Netherlands)

    Kootstra, G.; de Boer, B.; Schomaker, L.R.B.

    2011-01-01

    Most bottom-up models that predict human eye fixations are based on contrast features. The saliency model of Itti, Koch and Niebur is an example of such contrast-saliency models. Although the model has been successfully compared to human eye fixations, we show that it lacks preciseness in the

  11. [Treatment of femoral neck fracture--preference to internal fixation].

    Science.gov (United States)

    Minato, Izumi

    2011-03-01

    In the guidelines for the treatment of femoral neck fracture, prosthetic replacement is recommended in displaced one and internal fixation is in undisplaced one. However, in the long view, survived femoral head after internal fixation can be superior to prosthesis which will deteriorate as time goes by. Surgical method should be considered not only by type of fracture but general status of the patient.

  12. Tightrope fixation of ankle syndesmosis injuries: clinical outcome, complications and technique modification.

    LENUS (Irish Health Repository)

    Naqvi, Gohar A

    2012-06-01

    Ankle syndesmotic injuries are complex and require anatomic reduction and fixation. Tightrope fixation is a relatively new technique and we present the largest series of syndesmosis fixation using Arthrex Tightrope™ (Naples, FL, USA).

  13. Fixation and escape times in stochastic game learning

    International Nuclear Information System (INIS)

    Realpe-Gomez, John; Szczesny, Bartosz; Galla, Tobias; Dall’Asta, Luca

    2012-01-01

    Evolutionary dynamics in finite populations is known to fixate eventually in the absence of mutation. We here show that a similar phenomenon can be found in stochastic game dynamical batch learning, and investigate fixation in learning processes in a simple 2×2 game, for two-player games with cyclic interaction, and in the context of the best-shot network game. The analogues of finite populations in evolution are here finite batches of observations between strategy updates. We study when and how such fixation can occur, and present results on the average time-to-fixation from numerical simulations. Simple cases are also amenable to analytical approaches and we provide estimates of the behaviour of so-called escape times as a function of the batch size. The differences and similarities with escape and fixation in evolutionary dynamics are discussed. (paper)

  14. Biochemical and cytological effects of sulphur dioxide on plant metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Malhotra, S S; Hocking, D

    1976-01-01

    Biochemical effects of sulfur dioxide arise from its unique ability to act as an oxidizing or a reducing agent. Among some of the important metabolic effects are direct interference with photosynthetic CO/sub 2/ fixation (competitive inhibiton of ribulose diphosphate carbosylase by SO/sub 3/) and with energy metabolism (inhibition of mitochondrial ATP production by SO/sub 3//sup =/). Many indirect effects result from formation of sulfites and organic sulfonates with other cell constituents. These compounds can cause inhibition of a variety of metabolic enzyme systems. All these factors are probably instrumental in the gross disruption of chloroplast and mitochondrial ultrastructure. Injurious effects result when sulfur dioxide is taken up in excess of the capacity of the tissue to incorporate sulfur into the normal metabolic activities. The ubiquitous presence of small amounts of SO/sub 2/ and the subtle and varied nature of its biochemical effects suggest that crop losses to SO/sub 2/ pollution may be more widespread and serious than is generally suspected.

  15. Les aciers inoxydables dans les fixations

    CERN Document Server

    CETIM

    2010-01-01

    Cet ouvrage, qui fait la synthèse de plusieurs travaux menés par le Cetim, propose une vue d'ensemble sur les aciers inoxydables utilisés pour les fixations. Au sommaire : les normes EN, ISO et ATSM qui s'y rapportent , les désignations symboliques , les nuances et caractéristiques mécaniques , les différentes formes de corrosion, les méthodes pour les détecter , les règles du métier , les mises en oeuvre. L'ouvrage comprend plusieurs fiches matériaux et des tableaux qui présentent les équivalences entre les désignations.

  16. Nitrogen fixation by legumes in retorted shale

    Energy Technology Data Exchange (ETDEWEB)

    Hersman, L E; Molitoris, E; Klein, D A

    1981-01-01

    Although a soil-shale mixture was employed as the growth medium in this experiment, the results presentd are applicable to the proposed method of disposal mentioned earlier. Under field conditions, when covering the retorted shale with topsoil, some mixing of these materials might occur in the plant root region. In addition, it has been demonstrated that buried shale negatively affects enzyme activities in overburden surface soil. The occurrence of either of those events could affect symbiotic N/sub 2/ fixation in a manner similar to that reported in this paper. Researchers conclude that due to the varied effects of retorted shale on the legumes tested, further evaluation of other legumes may be necessary. Additional research would be required to determine which legumes have potential use for reclamation of retorted shale.

  17. Do you like what you see? The role of first fixation and total fixation duration in consumer choice

    NARCIS (Netherlands)

    Laan, van der L.N.; Hooge, I.T.C.; Ridder, de D.T.D.; Viergever, M.A.; Smeets, P.A.M.

    2015-01-01

    Although there has been recent growing interest in the associations between measures of visual attention and consumer choice, there is still uncertainty about the role of the first fixation in consumer choice and the factors that drive total fixation duration. The study aimed (1) to investigate the

  18. External Fixation versus two-stage Open Reduction Internal Fixation of distal intra-articular Tibia fractures; a Systematic Review

    DEFF Research Database (Denmark)

    Ladeby Erichsen, Julie; Jensen, Carsten; Damborg, Frank Lindhøj

    Internal Fixation (ORIF) or External Fixation (EF). Method : A search was conducted using PUBMED, Embase, Cochrane Central, Open Grey, Orthopaedic Proceedings and WHO International Clinical Trials Registry Platform. Studies with level of evidence I-IV comparing EF with two-stage ORIF of DIATF in patients...

  19. Do you like what you see? : The role of first fixation and total fixation duration in consumer choice

    NARCIS (Netherlands)

    van der Laan, Laura N.; Hooge, Ignace T C; De Ridder, Denise T D; Viergever, Max A.; Smeets, Paul A M

    2015-01-01

    Although there has been recent growing interest in the associations between measures of visual attention and consumer choice, there is still uncertainty about the role of the first fixation in consumer choice and the factors that drive total fixation duration. The study aimed (1) to investigate the

  20. A Meta-Analysis for Postoperative Complications in Tibial Plafond Fracture: Open Reduction and Internal Fixation Versus Limited Internal Fixation Combined With External Fixator.

    Science.gov (United States)

    Wang, Dong; Xiang, Jian-Ping; Chen, Xiao-Hu; Zhu, Qing-Tang

    2015-01-01

    The treatment of tibial plafond fractures is challenging to foot and ankle surgeons. Open reduction and internal fixation and limited internal fixation combined with an external fixator are 2 of the most commonly used methods of tibial plafond fracture repair. However, conclusions regarding the superior choice remain controversial. The present meta-analysis aimed to quantitatively compare the postoperative complications between open reduction and internal fixation and limited internal fixation combined with an external fixator for tibial plafond fractures. Nine studies with 498 fractures in 494 patients were included in the present study. The meta-analysis found no significant differences in bone healing complications (risk ratio [RR] 1.17, 95% confidence interval [CI] 0.68 to 2.01, p = .58], nonunion (RR 1.09, 95% CI 0.51 to 2.36, p = .82), malunion or delayed union (RR 1.24, 95% CI 0.57 to 2.69, p = .59), superficial (RR 1.56, 95% CI 0.43 to 5.61, p = .50) and deep (RR 1.89, 95% CI 0.62 to 5.80) infections, arthritis symptoms (RR 1.20, 95% CI 0.92 to 1.58, p = .18), or chronic osteomyelitis (RR 0.31, 95% CI 0.05 to 1.84, p = .20) between the 2 groups. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  1. Mini-Fragment Fixation Is Equivalent to Bicortical Screw Fixation for Horizontal Medial Malleolus Fractures.

    Science.gov (United States)

    Wegner, Adam M; Wolinsky, Philip R; Robbins, Michael A; Garcia, Tanya C; Amanatullah, Derek F

    2018-05-01

    Horizontal fractures of the medial malleolus occur through application of valgus or abduction force through the ankle that creates a tension failure of the medial malleolus. The authors hypothesize that mini-fragment T-plates may offer improved fixation, but the optimal fixation construct for these fractures remains unclear. Forty synthetic distal tibiae with identical osteotomies were randomized into 4 fixation constructs: (1) two parallel unicortical cancellous screws; (2) two parallel bicortical cortical screws; (3) a contoured mini-fragment T-plate with 2 unicortical screws in the fragment and 2 bicortical screws in the shaft; and (4) a contoured mini-fragment T-plate with 2 bicortical screws in the fragment and 2 unicortical screws in the shaft. Specimens were subjected to offset axial tension loading on a servohydraulic testing system and tracked using high-resolution video. Failure was defined as 2 mm of articular displacement. Analysis of variance followed by a Tukey-Kramer post hoc test was used to assess for differences between groups, with significance defined as Pfragment T-plate constructs (239±83 N/mm and 190±37 N/mm) and the bicortical screw construct (240±17 N/mm) were not statistically different. The mean stiffness values of both mini-fragment T-plate constructs and the bicortical screw construct were higher than that of a parallel unicortical screw construct (102±20 N/mm). Contoured T-plate constructs provide stiffer initial fixation than a unicortical cancellous screw construct. The T-plate is biomechanically equivalent to a bicortical screw construct, but may be superior in capturing small fragments of bone. [Orthopedics. 2018; 41(3):e395-e399.]. Copyright 2018, SLACK Incorporated.

  2. Phase-Contrast Hounsfield Units of Fixated and Non-Fixated Soft-Tissue Samples

    Science.gov (United States)

    Willner, Marian; Fior, Gabriel; Marschner, Mathias; Birnbacher, Lorenz; Schock, Jonathan; Braun, Christian; Fingerle, Alexander A.; Noël, Peter B.; Rummeny, Ernst J.; Pfeiffer, Franz; Herzen, Julia

    2015-01-01

    X-ray phase-contrast imaging is a novel technology that achieves high soft-tissue contrast. Although its clinical impact is still under investigation, the technique may potentially improve clinical diagnostics. In conventional attenuation-based X-ray computed tomography, radiological diagnostics are quantified by Hounsfield units. Corresponding Hounsfield units for phase-contrast imaging have been recently introduced, enabling a setup-independent comparison and standardized interpretation of imaging results. Thus far, the experimental values of few tissue types have been reported; these values have been determined from fixated tissue samples. This study presents phase-contrast Hounsfield units for various types of non-fixated human soft tissues. A large variety of tissue specimens ranging from adipose, muscle and connective tissues to liver, kidney and pancreas tissues were imaged by a grating interferometer with a rotating-anode X-ray tube and a photon-counting detector. Furthermore, we investigated the effects of formalin fixation on the quantitative phase-contrast imaging results. PMID:26322638

  3. "Cold" Fixation: Reconciliation of Nitrogen Fixation Rates and Diazotroph Assemblages in the Arctic Ocean

    Science.gov (United States)

    Fong, A. A.; Waite, A.; Rost, B.; Richter, K. U.

    2016-02-01

    Measurements of biological nitrogen fixation are typically conducted in oligotrophic subtropical and tropical marine environments where concentrations of fixed inorganic nitrogen are low. To date, only a handful of nitrogen fixation studies have been conducted in high latitude marine environments, but further investigation is needed to resolve the distribution of cold ocean diazotrophic assemblages. Nitrogen fixation rates and nifH gene distributions were measured at seven stations from 5°E to 20°E, north of 81°N in the Arctic Ocean at the onset of summer 2015. Discrete water samples in ice-covered regions were collected from the sea surface to 200 m for 15N2-tracer additions and targeted nifH gene and transcript analyses. Previous work suggests that heterotrophic bacteria dominate diazotrophic communities in the Arctic Ocean. Therefore, additional nifH gene surveys of sinking particles were conducted to test for enrichment on organic matter-rich microenvironments. Together, these measurements aim to reconcile diazotrophic activity with microbial community composition, further elucidating how nitrogen fixers could impact current concepts in polar carbon and nutrient cycling.

  4. Estimating environmental co-benefits of U.S. low-carbon pathways using the GCAM-USA integrated assessment model

    Data.gov (United States)

    U.S. Environmental Protection Agency — There are many technological pathways that can lead to reduced carbon dioxide (CO2) emissions. However, these pathways can have substantially different impacts on...

  5. Influences of Air, Oxygen, Nitrogen, and Carbon Dioxide Nanobubbles on Seed Germination and Plant Growth.

    Science.gov (United States)

    Ahmed, Ahmed Khaled Abdella; Shi, Xiaonan; Hua, Likun; Manzueta, Leidy; Qing, Weihua; Marhaba, Taha; Zhang, Wen

    2018-05-23

    Nanobubbles (NBs) hold promise in green and sustainable engineering applications in diverse fields (e.g., water/wastewater treatment, food processing, medical applications, and agriculture). This study investigated the effects of four types of NBs on seed germination and plant growth. Air, oxygen, nitrogen, and carbon dioxide NBs were generated and dispersed in tap water. Different plants, including lettuce, carrot, fava bean, and tomato, were used in germination and growth tests. The seeds in water-containing NBs exhibited 6-25% higher germination rates. Especially, nitrogen NBs exhibited considerable effects in the seed germination, whereas air and carbon dioxide NBs did not significantly promote germination. The growth of stem length and diameter, leave number, and leave width were promoted by NBs (except air). Furthermore, the promotion effect was primarily ascribed to the generation of exogenous reactive oxygen species by NBs and higher efficiency of nutrient fixation or utilization.

  6. Free flap reconstructions of tibial fractures complicated after internal fixation.

    Science.gov (United States)

    Nieminen, H; Kuokkanen, H; Tukiainen, E; Asko-Seljavaara, S

    1995-04-01

    The cases of 15 patients are presented where microvascular soft-tissue reconstructions became necessary after internal fixation of tibial fractures. Primarily, seven of the fractures were closed. Eleven fractures had originally been treated by open reduction and internal fixation using plates and screws, and four by intramedullary nailing. All of the patients suffered from postoperative complications leading to exposure of the bone or fixation material. The internal fixation material was removed and radical revision of dead and infected tissue was carried out in all cases. Soft tissue reconstruction was performed using a free microvascular muscle flap (11 latissimus dorsi, three rectus abdominis, and one gracilis). In eight cases the nonunion of the fracture indicated external fixation. The microvascular reconstruction was successful in all 15 patients. In one case the recurrence of deep infection finally indicated a below-knee amputation. In another case, chronic infection with fistulation recurred postoperatively. After a mean follow-up of 26 months the soft tissue coverage was good in all the remaining 13 cases. All the fractures united. Microvascular free muscle flap reconstruction of the leg is regarded as a reliable method for salvaging legs with large soft-tissue defects or defects in the distal leg. If after internal fixation of the tibial fracture the osteosynthesis material or fracture is exposed, reconstruction of the soft-tissue can successfully be performed by free flap transfer. By radical revision, external fixation, bone grafting, and a free flap the healing of the fracture can be achieved.

  7. Skin Graft Fixation Using Hydrofiber (Aquacel® Extra).

    Science.gov (United States)

    Yen, Ya-Hui; Lin, Chih-Ming; Hsu, Honda; Chen, Ying-Chen; Chen, Yi-Wen; Li, Wan-Yu; Hsieh, Chia-Nan; Huang, Chieh-Chi

    2018-06-01

    The traditional method of skin graft fixation is with tie-over bollus dressing. The use of splints in the extremities for skin graft fixation is a common practice. However, these splints are heavy and uncomfortable and contribute considerably to our overall medical waste. Hydrofiber (Aquacel Extra) has a strong fluid absorption property and fixates well to the underlying wound once applied. In this study, we used hydrofiber for fixation, avoiding the use of splints after skin grafting. A total of 56 patients reconstructed with split-thickness skin graft that was fixated only with hydrofiber between March 2015 and March 2016 were included in this retrospective study. There were 44 men and 12 women with a mean age of 61 ± 18 years. The defect size ranged from 1 × 1 cm for fingertips to 30 × 12 cm for lower limb defects. The average defect size was 61 ± 78 cm. The mean skin graft take was 96% ± 6%. Because splints were not required, we saved around 48 kg of medical waste over the space of 1 year. The use of hydrofiber for skin graft fixation was effective and technically very simple. Splints were not required with this method, decreasing the medical waste created and increasing patient comfort. We suggest that this is an excellent alternative for skin graft fixation while at the same time decreasing our carbon footprint as surgeons.

  8. Fracture healing using degradable magnesium fixation plates and screws.

    Science.gov (United States)

    Chaya, Amy; Yoshizawa, Sayuri; Verdelis, Kostas; Noorani, Sabrina; Costello, Bernard J; Sfeir, Charles

    2015-02-01

    Internal bone fixation devices made with permanent metals are associated with numerous long-term complications and may require removal. We hypothesized that fixation devices made with degradable magnesium alloys could provide an ideal combination of strength and degradation, facilitating fracture fixation and healing while eliminating the need for implant removal surgery. Fixation plates and screws were machined from 99.9% pure magnesium and compared with titanium devices in a rabbit ulnar fracture model. Magnesium device degradation and the effect on fracture healing and bone formation were assessed after 4 weeks. Fracture healing with magnesium device fixation was compared with that of titanium devices using qualitative histologic analysis and quantitative histomorphometry. Micro-computed tomography showed device degradation after 4 weeks in vivo. In addition, 2-dimensional micro-computed tomography slices and histologic staining showed that magnesium degradation did not inhibit fracture healing or bone formation. Histomorphology showed no difference in bone-bridging fractures fixed with magnesium and titanium devices. Interestingly, abundant new bone was formed around magnesium devices, suggesting a connection between magnesium degradation and bone formation. Our results show potential for magnesium fixation devices in a loaded fracture environment. Furthermore, these results suggest that magnesium fixation devices may enhance fracture healing by encouraging localized new bone formation. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  9. Carbon dioxide: emissions and effects

    Energy Technology Data Exchange (ETDEWEB)

    Smith, I M

    1982-01-01

    This review provides a comprehensive guide to work carried out since 1978 in the many disciplines involved in this complex issue. Possible scenarios for carbon dioxide emissions, sources and sinks in the carbon cycle and for climatic changes are examined. The current concensus (by no means unanimous) of specialists on this issue appears to be that a continuation of reduced trends in energy consumption since 1973 is likely to double the atmospheric carbon dioxide concentration to 600 ppmv during the latter part of the next century. However, a higher demand scenario, requiring an upper limit of coal production, would bring forward the doubling to about the middle of the next century. Current climatic models predict that such a concentration of carbon dioxide would cause an average global warming of from 1.0 to 4.5/sup 0/C which might be delayed by the thermal inertia of the oceans. A warming due to estimated increases in carbon dioxide should, if the model results are correct, become apparent at the end of this century. Regional climatic changes are likely to vary considerably and prove disadvantageous to some regions and beneficial to others. Different strategies for dealing with the carbon dioxide issue are considered: no response, alleviation, countermeasures and prevention. It is concluded that uncertainties do not justify either the use of carbon dioxide disposal and other technical fixes at present or a policy of no further growth in fossil fuel consumption. On the other hand, major efforts to conserve energy would give more time to adapt to changes. The alleviation of climatic impacts and other desirable dual-benefit measures are advocated in addition to continuing international, interdisciplinary research on all aspects.

  10. Design and Optimization of Resorbable Silk Internal Fixation Devices

    Science.gov (United States)

    Haas, Dylan S.

    Limitations of current material options for internal fracture fixation devices have resulted in a large gap between user needs and hardware function. Metal systems offer robust mechanical strength and ease of implantation but require secondary surgery for removal and/or result in long-term complications (infection, palpability, sensitivity, etc.). Current resorbable devices eliminate the need for second surgery and long-term complications but are still associated with negative host response as well as limited functionality and more difficult implantation. There is a definitive need for orthopedic hardware that is mechanically capable of immediate fracture stabilization and fracture fixation during healing, can safely biodegrade while allowing complete bone remodeling, can be resterilized for reuse, and is easily implantable (self-tapping). Previous work investigated the use of silk protein to produce resorbable orthopedic hardware for non- load bearing fracture fixation. In this study, silk orthopedic hardware was further investigated and optimized in order to better understand the ability of silk as a fracture fixation system and more closely meet the unfulfilled market needs. Solvent-based and aqueous-based silk processing formulations were cross-linked with methanol to induce beta sheet structure, dried, autoclaved and then machined to the desired device/geometry. Silk hardware was evaluated for dry, hydrated and fatigued (cyclic) mechanical properties, in vitro degradation, resterilization, functionalization with osteoinductive molecules and implantation technique for fracture fixation. Mechanical strength showed minor improvements from previous results, but remains comparable to current resorbable fixation systems with the advantages of self-tapping ability for ease of implantation, full degradation in 10 months, ability to be resterilized and reused, and ability to release molecules for osteoinudction. In vivo assessment confirmed biocompatibility, showed

  11. Carbon Dioxide Absorption Heat Pump

    Science.gov (United States)

    Jones, Jack A. (Inventor)

    2002-01-01

    A carbon dioxide absorption heat pump cycle is disclosed using a high pressure stage and a super-critical cooling stage to provide a non-toxic system. Using carbon dioxide gas as the working fluid in the system, the present invention desorbs the CO2 from an absorbent and cools the gas in the super-critical state to deliver heat thereby. The cooled CO2 gas is then expanded thereby providing cooling and is returned to an absorber for further cycling. Strategic use of heat exchangers can increase the efficiency and performance of the system.

  12. Early Experience with Biodegradable Fixation of Pediatric Mandibular Fractures

    OpenAIRE

    Mazeed, Ahmed Salah; Shoeib, Mohammed Abdel-Raheem; Saied, Samia Mohammed Ahmed; Elsherbiny, Ahmed

    2014-01-01

    This clinical study aims to evaluate the stability and efficiency of biodegradable self-reinforced poly-l/dl-lactide (SR-PLDLA) plates and screws for fixation of pediatric mandibular fractures. The study included 12 patients (3–12 years old) with 14 mandibular fractures. They were treated by open reduction and internal fixation by SR-PLDLA plates and screws. Maxillomandibular fixation was maintained for 1 week postoperatively. Clinical follow-up was performed at 1 week, 6 weeks, 3 months, and...

  13. Operative Fixation Options for Elective and Diabetic Ankle Arthrodesis.

    Science.gov (United States)

    Ramanujam, Crystal L; Stapleton, John J; Zgonis, Thomas

    2017-07-01

    Ankle arthrodesis remains one of the most definitive treatment options for end-stage arthritis, paralysis, posttraumatic and postinfectious conditions, failed total ankle arthroplasty, and severe deformities. The general aims of ankle arthrodesis are to decrease pain and instability, correct the accompanying deformity, and create a stable plantigrade foot. Several surgical approaches have been reported for ankle arthrodesis with internal fixation options. External fixation has also evolved for ankle arthrodesis in certain clinical scenarios. This article provides a comprehensive analysis of midterm to long-term outcomes for ankle arthrodesis using internal and/or external fixation each for elective and diabetic conditions. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. Carbon Dioxide Embolism during Laparoscopic Surgery

    Science.gov (United States)

    Park, Eun Young; Kwon, Ja-Young

    2012-01-01

    Clinically significant carbon dioxide embolism is a rare but potentially fatal complication of anesthesia administered during laparoscopic surgery. Its most common cause is inadvertent injection of carbon dioxide into a large vein, artery or solid organ. This error usually occurs during or shortly after insufflation of carbon dioxide into the body cavity, but may result from direct intravascular insufflation of carbon dioxide during surgery. Clinical presentation of carbon dioxide embolism ranges from asymptomatic to neurologic injury, cardiovascular collapse or even death, which is dependent on the rate and volume of carbon dioxide entrapment and the patient's condition. We reviewed extensive literature regarding carbon dioxide embolism in detail and set out to describe the complication from background to treatment. We hope that the present work will improve our understanding of carbon dioxide embolism during laparoscopic surgery. PMID:22476987

  15. Noninvasive patient fixation for extracranial stereotactic radiotherapy

    International Nuclear Information System (INIS)

    Lohr, Frank; Debus, Juergen; Frank, Claudia; Herfarth, Klaus; Pastyr, Otto; Rhein, Bernhard; Bahner, Malte L.; Schlegel, Wolfgang; Wannenmacher, Michael

    1999-01-01

    Purpose: To evaluate the setup accuracy that can be achieved with a novel noninvasive patient fixation technique based on a body cast attached to a recently developed stereotactic body frame during fractionated extracranial stereotactic radiotherapy. Methods and Materials: Thirty-one CT studies (≥ 20 slices, thickness: 3 mm) from 5 patients who were immobilized in a body cast attached to a stereotactic body frame for treatment of para medullary tumors in the thoracic or lumbar spine were evaluated with respect to setup accuracy. The immobilization device consisted of a custom-made wrap-around body cast that extended from the neck to the thighs and a separate head mask, both made from Scotchcast. Each CT study was performed immediately before or after every second or third actual treatment fraction without repositioning the patient between CT and treatment. The stereotactic localization system was mounted and the isocenter as initially located stereo tactically was marked with fiducials for each CT study. Deviation of the treated isocenter as compared to the planned position was measured in all three dimensions. Results: The immobilization device can be easily handled, attached to and removed from the stereotactic frame and thus enables treatment of multiple patients with the same stereotactic frame each day. Mean patient movements of 1.6 mm ± 1.2 mm (laterolateral [LL]), 1.4 mm ± 1.0 mm (anterior-posterior [AP]), 2.3 mm ± 1.3 mm (transversal vectorial error [VE]) and < slice thickness = 3 mm (cranio caudal [CC]) were recorded for the targets in the thoracic spine and 1.4 mm ± 1.0 mm (LL), 1.2 mm ± 0.7 mm (AP), 1.8 mm ± 1.2 mm (VE), and < 3 mm (CC) for the lumbar spine. The worst case deviation was 3.9 mm for the first patient with the target in the thoracic spine (in the LL direction). Combining those numbers (mean transversal VE for both locations and maximum CC error of 3 mm), the mean three-dimensional vectorial patient movement and thus the mean overall

  16. Biomechanical stability of a supra-acetabular pedicle screw internal fixation device (INFIX) vs external fixation and plates for vertically unstable pelvic fractures.

    Science.gov (United States)

    Vigdorchik, Jonathan M; Esquivel, Amanda O; Jin, Xin; Yang, King H; Onwudiwe, Ndidi A; Vaidya, Rahul

    2012-09-27

    We have recently developed a subcutaneous anterior pelvic fixation technique (INFIX). This internal fixator permits patients to sit, roll over in bed and lie on their sides without the cumbersome external appliances or their complications. The purpose of this study was to evaluate the biomechanical stability of this novel supraacetabular pedicle screw internal fixation construct (INFIX) and compare it to standard internal fixation and external fixation techniques in a single stance pelvic fracture model. Nine synthetic pelves with a simulated anterior posterior compression type III injury were placed into three groups (External Fixator, INFIX and Internal Fixation). Displacement, total axial stiffness, and the stiffness at the pubic symphysis and SI joint were calculated. Displacement and stiffness were compared by ANOVA with a Bonferroni adjustment for multiple comparisons The mean displacement at the pubic symphysis was 20, 9 and 0.8 mm for external fixation, INFIX and internal fixation, respectively. Plate fixation was significantly stiffer than the INFIX and external Fixator (P = 0.01) at the symphysis pubis. The INFIX device was significantly stiffer than external fixation (P = 0.017) at the symphysis pubis. There was no significant difference in SI joint displacement between any of the groups. Anterior plate fixation is stiffer than both the INFIX and external fixation in single stance pelvic fracture model. The INFIX was stiffer than external fixation for both overall axial stiffness, and stiffness at the pubic symphysis. Combined with the presumed benefit of minimizing the complications associated with external fixation, the INFIX may be a more preferable option for temporary anterior pelvic fixation in situations where external fixation may have otherwise been used.

  17. Communication: Photoinduced carbon dioxide binding with surface-functionalized silicon quantum dots

    Science.gov (United States)

    Douglas-Gallardo, Oscar A.; Sánchez, Cristián Gabriel; Vöhringer-Martinez, Esteban

    2018-04-01

    Nowadays, the search for efficient methods able to reduce the high atmospheric carbon dioxide concentration has turned into a very dynamic research area. Several environmental problems have been closely associated with the high atmospheric level of this greenhouse gas. Here, a novel system based on the use of surface-functionalized silicon quantum dots (sf-SiQDs) is theoretically proposed as a versatile device to bind carbon dioxide. Within this approach, carbon dioxide trapping is modulated by a photoinduced charge redistribution between the capping molecule and the silicon quantum dots (SiQDs). The chemical and electronic properties of the proposed SiQDs have been studied with a Density Functional Theory and Density Functional Tight-Binding (DFTB) approach along with a time-dependent model based on the DFTB framework. To the best of our knowledge, this is the first report that proposes and explores the potential application of a versatile and friendly device based on the use of sf-SiQDs for photochemically activated carbon dioxide fixation.

  18. Hodgkin's disease following thorium dioxide angiography

    Energy Technology Data Exchange (ETDEWEB)

    Gotlieb, A I; Kirk, M E [McGill Univ., Montreal, Quebec (Canada). Dept. of Pathology; Hutchison, J L [Montreal General Hospital, Quebec (Canada)

    1976-09-04

    Hodgkin's disease occurred in a 53-year-old man who, 25 years previously, had undergone cerebral angiography, for which thorium dioxide suspension (Thorotrast) was used. Deposits of thorium dioxide were noted in reticuloendothelial cells in various locations. An association between thorium dioxide administration and the subsequent development of malignant tumours and neoplastic hematologic disorders has previously been reported.

  19. 21 CFR 582.1240 - Carbon dioxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Carbon dioxide. 582.1240 Section 582.1240 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS....1240 Carbon dioxide. (a) Product. Carbon dioxide. (b) Conditions of use. This substance is generally...

  20. 21 CFR 73.1575 - Titanium dioxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.1575 Section 73.1575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Drugs § 73.1575 Titanium dioxide. (a) Identity and specifications. (1) The color additive titanium dioxide shall conform in identity and specifications to the requirements...

  1. 40 CFR 180.1195 - Titanium dioxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Titanium dioxide. 180.1195 Section 180.1195 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) PESTICIDE PROGRAMS... Titanium dioxide. Titanium dioxide is exempted from the requirement of a tolerance for residues in or on...

  2. 21 CFR 73.2575 - Titanium dioxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.2575 Section 73.2575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Cosmetics § 73.2575 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide shall conform in identity and specifications to the requirements...

  3. 21 CFR 73.575 - Titanium dioxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.575 Section 73.575 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.575 Titanium dioxide. (a) Identity. (1) The color additive titanium dioxide is synthetically prepared TiO2, free from admixture with other substances. (2) Color...

  4. 21 CFR 73.3126 - Titanium dioxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Titanium dioxide. 73.3126 Section 73.3126 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Medical Devices § 73.3126 Titanium dioxide. (a) Identity and specifications. The color additive titanium dioxide (CAS Reg. No. 13463-67-7), Color Index No. 77891, shall...

  5. Modelling Sublimation of Carbon Dioxide

    Science.gov (United States)

    Winkel, Brian

    2012-01-01

    In this article, the author reports results in their efforts to model sublimation of carbon dioxide and the associated kinetics order and parameter estimation issues in their model. They have offered the reader two sets of data and several approaches to determine the rate of sublimation of a piece of solid dry ice. They presented several models…

  6. Thermal conductivity of uranium dioxide

    International Nuclear Information System (INIS)

    Pillai, C.G.S.; George, A.M.

    1993-01-01

    The thermal conductivity of uranium dioxide of composition UO 2.015 was measured from 300 to 1400 K. The phonon component of the conductivity is found to be quantitatively accounted for by the theoretical expression of Slack derived by modifying the Leibfried-Schlomann equation. (orig.)

  7. Necrotizing fasciitis after internal fixation of fracture of femoral trochanteric ? ??

    OpenAIRE

    Santos, Leandro Em?lio Nascimento; Pires, Robinson Esteves Santos; Figueiredo, Leonardo Brand?o; Soares, Eduardo Augusto Marques

    2014-01-01

    Necrotizing fasciitis is a rare and potentially lethal soft tissue infection. We report a case of trochanteric femur fracture in a patient who underwent fracture fixation and developed necrotizing fasciitis. A literature review on the topic will be addressed.

  8. Use of 15N methodology to assess biological nitrogen fixation

    International Nuclear Information System (INIS)

    Hardarson, G.

    1990-01-01

    One of the most important characteristics of legumes are their ability in symbiosis with Rhizobium bacteria to fix atmospheric nitrogen for growth. For proper management and a full realization of the benefits of this plant-microbial association, it is necessary to estimate how much nitrogen is fixed under different conditions in the field. It is only after this is known that various factors can be manipulated so as to increase the amount and proportion of N a plant derives from biological fixation. A suitable method for accurately measuring the amount of N crops derive from fixation is therefore an important requirement in any programme aimed at maximizing biological nitrogen fixation. There are several methods available to measure N 2 fixation (Bergersen, 1980) based on (1) increment in N yield and plant growth, (2) nitrogen balance (3) acetylene reduction and (4) the use of isotopes of N. Only isotopic methods will be illustrated here. 20 refs, 2 figs, 9 tabs

  9. Outcome of complex tibial plateau fractures treated with external fixator

    Directory of Open Access Journals (Sweden)

    Sushil H Mankar

    2012-01-01

    Conclusion: We believe that minimally invasive treatment by percutaneous techniques and external fixation is a fairly reasonable treatment alternative, if near anatomical reduction of joint surface can be confirmed on fluoroscopy.

  10. Biomechanical analysis of titanium fixation plates and screws in ...

    African Journals Online (AJOL)

    hole Y plates with monocortical screws. 150 N incisal occlusal loads were simulated on the models. The commercial ANSYS software was utilized to calculate the Von Mises stresses on fixative appliances. Results: The highest Von Mises stress ...

  11. Cyanobacteria Occurrence and Nitrogen Fixation Rates in the ...

    African Journals Online (AJOL)

    Keywords: Cyanobacteria, Nitrogen Fixation, Seagrass, Seaweed Farming. Abstract—The .... during every sampling period, using a mercury thermometer and a ..... Capone, D.G. (1993) Determination of nitrogenase activity in aquatic samples ...

  12. A new 3-dimensional head fixation device for brain imaging

    International Nuclear Information System (INIS)

    Goto, Ryoi; Kawashima, Ryuta; Yoshioka, Seiro; Ono, Shuichi; Ito, Hiroshi; Sato, Kazunori; Akaizawa, Takashi; Koyama, Masamichi; Fukuda, Hiroshi

    1995-01-01

    We have developed a new head fixation device for studies of brain function. This device was designed to immobilize subject's heads during image scanning and to precisely reproduce the head position for two different imaging modalities such as MRI and PET. The device consists of a plastic frame, a pillow filled with beads of styrene foam, and a face mask of thermoplastic resin which was originally intended for application in radiotherapy. A bridge for biting was incorporated into the mask for stable fixation. The device enables immobilization of subject's heads with good reproducibility of position at the practical level. Our results indicate that this head fixation system is useful for fixation of head during activation studies using PET. (author)

  13. Nitrogen fixation rates in the eastern Arabian Sea

    Digital Repository Service at National Institute of Oceanography (India)

    Ahmed, A.; Gauns, M.; Kurian, S.; Bardhan, P.; Pratihary, A.K.; Naik, H.; Shenoy, D.M.; Naqvi, S.W.A.

    The Arabian Sea experiences bloom of the diazotroph Trichodesmium during certain times of the year when optimal sea surface temperature and oligotrophic condition favour their growth. We measured nitrogen fixation rates in the euphotic zone during...

  14. Symbiotic N fixation of several soybean varieties and mutants

    International Nuclear Information System (INIS)

    Soertini, G.; Hendratno

    1988-01-01

    Symbiotic N fixation of several soybean varieties and mutants. Research activities comprising of three experiments were carried out to screen several soybean varieties and mutants for symbiotic N fixation potential. The first two experiments involved screening of seven rhizobium strains/isolate for effective N fixation. Depending on the medium used, plant response to strains was different. In sterile medium, rhizobium strain USDA 136, 142 and TAL 102 showed a high nitrogen fixation potential. In soil only rhizobium strain USDA 110 had better performance and proved to be competitive to the native strains. Nitrogen-15 dilution method was used to screen nitrogen fixing ability of several soybean varieties and mutants. Guntur variety showed a better response to high dose of N fertilizer without disturbance in its fixing ability. This variety then was considered good to be introduced in the cropping system. (author). 8 refs

  15. Fixation of tritium in a highly stable polymer form

    International Nuclear Information System (INIS)

    Steinberg, M.; Colombo, P.; Pruzansky, J.

    1977-01-01

    A method for the fixation of tritium comprises reacting tritiated water with calcium carbide to produce calcium hydroxide and tritiated acetylene, polymerizing the acetylene, and then incorporating the polymer in a solidifying matrix. 2 claims

  16. Improving food and agricultural production. Thailand. Biological nitrogen fixation

    International Nuclear Information System (INIS)

    Bowen, G.D.

    1991-01-01

    The aim of the mission was to assist the counterpart scientists in the analysis and interpretation of data relating to nitrogen fixation studies on grain legumes. The report briefly summarizes the discussions that were held with the counterparts

  17. The Role of Personality and Team-Based Product Dissection on Fixation Effects

    Science.gov (United States)

    Toh, Christine; Miller, Scarlett; Kremer, Gül E. Okudan

    2013-01-01

    Design fixation has been found to be complex in its definition and expression, but it plays an important role in design idea generation. Identifying the factors that influence fixation is crucial in understanding how to enhance the design process and reduce the negative effects of fixation. One way to potentially mitigate fixation is through…

  18. A Medicago truncatula tobacco retrotransposon insertion mutant collection with defects in nodule development and symbiotic nitrogen fixation.

    Science.gov (United States)

    Pislariu, Catalina I; Murray, Jeremy D; Wen, JiangQi; Cosson, Viviane; Muni, RajaSekhara Reddy Duvvuru; Wang, Mingyi; Benedito, Vagner A; Andriankaja, Andry; Cheng, Xiaofei; Jerez, Ivone Torres; Mondy, Samuel; Zhang, Shulan; Taylor, Mark E; Tadege, Million; Ratet, Pascal; Mysore, Kirankumar S; Chen, Rujin; Udvardi, Michael K

    2012-08-01

    A Tnt1-insertion mutant population of Medicago truncatula ecotype R108 was screened for defects in nodulation and symbiotic nitrogen fixation. Primary screening of 9,300 mutant lines yielded 317 lines with putative defects in nodule development and/or nitrogen fixation. Of these, 230 lines were rescreened, and 156 lines were confirmed with defective symbiotic nitrogen fixation. Mutants were sorted into six distinct phenotypic categories: 72 nonnodulating mutants (Nod-), 51 mutants with totally ineffective nodules (Nod+ Fix-), 17 mutants with partially ineffective nodules (Nod+ Fix+/-), 27 mutants defective in nodule emergence, elongation, and nitrogen fixation (Nod+/- Fix-), one mutant with delayed and reduced nodulation but effective in nitrogen fixation (dNod+/- Fix+), and 11 supernodulating mutants (Nod++Fix+/-). A total of 2,801 flanking sequence tags were generated from the 156 symbiotic mutant lines. Analysis of flanking sequence tags revealed 14 insertion alleles of the following known symbiotic genes: NODULE INCEPTION (NIN), DOESN'T MAKE INFECTIONS3 (DMI3/CCaMK), ERF REQUIRED FOR NODULATION, and SUPERNUMERARY NODULES (SUNN). In parallel, a polymerase chain reaction-based strategy was used to identify Tnt1 insertions in known symbiotic genes, which revealed 25 additional insertion alleles in the following genes: DMI1, DMI2, DMI3, NIN, NODULATION SIGNALING PATHWAY1 (NSP1), NSP2, SUNN, and SICKLE. Thirty-nine Nod- lines were also screened for arbuscular mycorrhizal symbiosis phenotypes, and 30 mutants exhibited defects in arbuscular mycorrhizal symbiosis. Morphological and developmental features of several new symbiotic mutants are reported. The collection of mutants described here is a source of novel alleles of known symbiotic genes and a resource for cloning novel symbiotic genes via Tnt1 tagging.

  19. Nitrogen supply of crops by biological nitrogen fixation. 2

    International Nuclear Information System (INIS)

    Jensen, E.S.; Andersen, A.J.; Soerensen, H.; Thomsen, J.D.

    1985-02-01

    In the present work the contributions from combined N-sources and symbiotic nitrogen fixation to the nitrogen supply of field-grown peas and field beans were evaluated by means of 15 N fertilizer dilution. The effect of N-fertilizer, supplied at sowing and at different stages of plant development, on nitrogen fixation, yield and protein production in peas, was studied in pot experiments. (author)

  20. A Novel Handmade External Fixator for Phalangeal and Metacarpal Fractures

    Directory of Open Access Journals (Sweden)

    Davod Jafari

    2016-12-01

    Full Text Available Background The value of external fixation in complex hand injuries is well established. Expenses and technical difficulties of commercial mini external fixator sets have led to the innovation of handmade external fixators. These fixators are used as versatile facilities to treat certain hand fractures. Usually, these structures are made by k-wires crossed filled with cement plastic tube. However, these fixators have multiple deficiencies that should be addressed. Objectives In this study, we described in detail the surgical technique of a handmade concrete like mini external fixator and report its clinical use and results. Methods Our handmade external fixator was applied for 52 patients with 56 fractures. Only 5% of the fractures were closed, non-comminuted extra-articular, and the other 51 fractures were more complex injuries. The mean follow up time was 9.3 months. At the end of the follow up, radiologic and functional assessment (DASH: Disability of arm, shoulder and hand and TAM: Total active motion was evaluated. Results All 56 fractures were united completely. None of the cases experienced pin loosening or reduction loss. Of the fractures, 8.9% malunited due to fracture complexity. The mean dash score was 3.76. TAM was excellent in 45% of the fractures; it was good in 7% and fair in 4%. Conclusions This type of handmade external fixator is simple, lightweight, and cheap. Furthermore, all implements are readily available in most operating fields. The probability of loosening has been greatly diminished because of the concrete like structure. Easy and fast assembly and good clinical and functional results are the other advantages of this technique. Due to the less complication and benefits, this technique could be used for many phalangeal and metacarpal fractures with confidence.

  1. Postinflammatory ossicular fixation: CT analysis with surgical correlation

    International Nuclear Information System (INIS)

    Swartz, J.D.; Wolfson, R.J.; Marlowe, F.I.; Popky, G.L.

    1985-01-01

    Postinflammatory ossicular fixation is a common problem encountered by the otologic surgeon upon exploration because of conductive hearing loss in patients with chronic otitis media. These nonotosclerotic noncongenital lesions take three pathologic forms: fibrous tissue fixation (chronic adhesive otitis media), hyalinization of collagen (tympanosclerosis), and new bone formation (fibro-osseous sclerosis). More than 300 patients with the clinical diagnosis of chronic otitis media have been examined. This study encompasses 23 proved cases

  2. External fixation of tibial pilon fractures and fracture healing.

    Science.gov (United States)

    Ristiniemi, Jukka

    2007-06-01

    Distal tibial fractures are rare and difficult to treat because the bones are subcutaneous. External fixation is commonly used, but the method often results in delayed union. The aim of the present study was to find out the factors that affect fracture union in tibial pilon fractures. For this purpose, prospective data collection of tibial pilon fractures was carried out in 1998-2004, resulting in 159 fractures, of which 83 were treated with external fixation. Additionally, 23 open tibial fractures with significant > 3 cm bone defect that were treated with a staged method in 2000-2004 were retrospectively evaluated. The specific questions to be answered were: What are the risk factors for delayed union associated with two-ring hybrid external fixation? Does human recombinant BMP-7 accelerate healing? What is the role of temporary ankle-spanning external fixation? What is the healing potential of distal tibial bone loss treated with a staged method using antibiotic beads and subsequent autogenous cancellous grafting compared to other locations of the tibia? The following risk factors for delayed healing after external fixation were identified: post-reduction fracture gap of >3 mm and fixation of the associated fibula fracture. Fracture displacement could be better controlled with initial temporary external fixation than with early definitive fixation, but it had no significant effect on healing time, functional outcome or complication rate. Osteoinduction with rhBMP-7 was found to accelerate fracture healing and to shorten the sick leave. A staged method using antibiotic beads and subsequent autogenous cancellous grafting proved to be effective in the treatment of tibial bone loss. Healing potential of the bone loss in distal tibia was at least equally good as in other locations of the tibia.

  3. Bilateral spontaneous subluxation of scleral-fixated intraocular lenses.

    Science.gov (United States)

    Assia, Ehud I; Nemet, Arie; Sachs, Dani

    2002-12-01

    Two young men with primary ectopic lenses had intracapsular cataract extraction and scleral fixation of posterior chamber intraocular lenses (PC IOLs) using 10-0 polypropylene sutures tied to the IOL eyelets. Three to 9 years after implantation, spontaneous IOL vertical subluxation occurred in all 4 eyes (5 IOL loops), probably because of suture breakage. Late subluxation of a sutured IOL may occur several years after implantation. Double fixation and thicker sutures should be considered, especially in young patients.

  4. Nitrogen fixation in peanut nodules during dark periods and detopped conditions with special reference to lipid bodies

    International Nuclear Information System (INIS)

    Siddique, A.M.; Bal, A.K.

    1991-01-01

    The peanut plant (Arachis hypogaea L.), unlike other known legumes, can sustain nitrogen fixation when prolonged periods of darkness or detopping curtail the supply of photosynthate to the nodule. This ability to withstand photosynthate stress is attributed to the presence of lipid bodies in infected nodule cells. In both dark-treated and detopped plants, the lipid bodies show a gradual decrease in numbers, suggesting their utilization as a source of energy and carbon for nitrogen fixation. Lipolytic activity can be localized in the lipid bodies, and the existence of β-oxidation pathway and glyoxylate cycle is shown by the release of 14 CO 2 from 14 C lineoleoyl coenzyme A by the nodule homogenate

  5. Plant densities and modulation of symbiotic nitrogen fixation in soybean

    Directory of Open Access Journals (Sweden)

    Marcos Javier de Luca

    2014-06-01

    Full Text Available Soybean nitrogen (N demands can be supplied to a large extent via biological nitrogen fixation, but the mechanisms of source/sink regulating photosynthesis/nitrogen fixation in high yielding cultivars and current crop management arrangements need to be investigated. We investigated the modulation of symbiotic nitrogen fixation in soybean [Glycine max (L. Merrill] at different plant densities. A field trial was performed in southern Brazil with six treatments, including non-inoculated controls without and with N-fertilizer, both at a density of 320,000 plants ha−1, and plants inoculated with Bradyrhizobium elkanii at four densities, ranging from 40,000 to 320,000 plants ha−1. Differences in nodulation, biomass production, N accumulation and partition were observed at stage R5, but not at stage V4, indicating that quantitative and qualitative factors (such as sunlight infrared/red ratio assume increasing importance during the later stages of plant growth. Decreases in density in the inoculated treatments stimulated photosynthesis and nitrogen fixation per plant. Similar yields were obtained at the different plant densities, with decreases only at the very low density level of 40,000 plants ha−1, which was also the only treatment to show differences in seed protein and oil contents. Results confirm a fine tuning of the mechanisms of source/sink, photosynthesis/nitrogen fixation under lower plant densities. Higher photosynthesis and nitrogen fixation rates are capable of sustaining increased plant growth.

  6. Effects of tissue fixation and dehydration on tendon collagen nanostructure.

    Science.gov (United States)

    Turunen, Mikael J; Khayyeri, Hanifeh; Guizar-Sicairos, Manuel; Isaksson, Hanna

    2017-09-01

    Collagen is the most prominent protein in biological tissues. Tissue fixation is often required for preservation or sectioning of the tissue. This may affect collagen nanostructure and potentially provide incorrect information when analyzed after fixation. We aimed to unravel the effect of 1) ethanol and formalin fixation and 2) 24h air-dehydration on the organization and structure of collagen fibers at the nano-scale using small and wide angle X-ray scattering. Samples were divided into 4 groups: ethanol fixed, formalin fixed, and two untreated sample groups. Samples were allowed to air-dehydrate in handmade Kapton pockets during the measurements (24h) except for one untreated group. Ethanol fixation affected the collagen organization and nanostructure substantially and during 24h of dehydration dramatic changes were evident. Formalin fixation had minor effects on the collagen organization but after 12h of air-dehydration the spatial variation increased substantially, not evident in the untreated samples. Generally, collagen shrinkage and loss of alignment was evident in all samples during 24h of dehydration but the changes were subtle in all groups except the ethanol fixed samples. This study shows that tissue fixation needs to be chosen carefully in order to preserve the features of interest in the tissue. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Fractures of the proximal fifth metatarsal: percutaneous bicortical fixation.

    Science.gov (United States)

    Mahajan, Vivek; Chung, Hyun Wook; Suh, Jin Soo

    2011-06-01

    Displaced intraarticular zone I and displaced zone II fractures of the proximal fifth metatarsal bone are frequently complicated by delayed nonunion due to a vascular watershed. Many complications have been reported with the commonly used intramedullary screw fixation for these fractures. The optimal surgical procedure for these fractures has not been determined. All these observations led us to evaluate the effectiveness of percutaneous bicortical screw fixation for treating these fractures. Twenty-three fractures were operatively treated by bicortical screw fixation. All the fractures were evaluated both clinically and radiologically for the healing. All the patients were followed at 2 or 3 week intervals till fracture union. The patients were followed for an average of 22.5 months. Twenty-three fractures healed uneventfully following bicortical fixation, with a mean healing time of 6.3 weeks (range, 4 to 10 weeks). The average American Orthopaedic Foot & Ankle Society (AOFAS) score was 94 (range, 90 to 99). All the patients reported no pain at rest or during athletic activity. We removed the implant in all cases at a mean of 23.2 weeks (range, 18 to 32 weeks). There was no refracture in any of our cases. The current study shows the effectiveness of bicortical screw fixation for displaced intraarticular zone I fractures and displaced zone II fractures. We recommend it as one of the useful techniques for fixation of displaced zone I and II fractures.

  8. Antibotulinal efficacy of sulfur dioxide in meat.

    Science.gov (United States)

    Tompkin, R B; Christiansen, L N; Shaparis, A B

    1980-01-01

    The addition of sodium metabisulfite as a source of sulfur dioxide delayed botulinal outgrowth in perishable canned comminuted pork when it was temperature abused at 27 degree C. The degree of inhibition was directly related to the level of sulfur dioxide. Levels greater than 100 microgram of sulfur dioxide per g were necessary to achieve significant inhibition when a target level of 100 botulinal spores per g was used. Sodium nitrite partially reduced the efficacy of the sulfur dioxide. Sulfur dioxide offers a new option for the control of botulinal outgrowth in cured or noncured meat and poultry products. PMID:6996613

  9. Perspectives in the use of carbon dioxide

    Directory of Open Access Journals (Sweden)

    Aresta Michele

    1999-01-01

    Full Text Available The mitigation of carbon dioxide is one of the scientific and technological challenges of the 2000s. Among the technologies that are under assessment, the recovery of carbon dioxide from power plants or industrial flue gases plays a strategic role. Recovered carbon dioxide can be either disposed in natural fields or used. The availability of large amounts of carbon dioxide may open new routes to its utilisation in biological, chemical and innovative technological processes. In this paper, the potential of carbon dioxide utilisation in the short-, medium-term is reviewed.

  10. The Biological Deep Sea Hydrothermal Vent as a Model to Study Carbon Dioxide Capturing Enzymes

    Directory of Open Access Journals (Sweden)

    Premila D. Thongbam

    2011-04-01

    Full Text Available Deep sea hydrothermal vents are located along the mid-ocean ridge system, near volcanically active areas, where tectonic plates are moving away from each other. Sea water penetrates the fissures of the volcanic bed and is heated by magma. This heated sea water rises to the surface dissolving large amounts of minerals which provide a source of energy and nutrients to chemoautotrophic organisms. Although this environment is characterized by extreme conditions (high temperature, high pressure, chemical toxicity, acidic pH and absence of photosynthesis a diversity of microorganisms and many animal species are specially adapted to this hostile environment. These organisms have developed a very efficient metabolism for the assimilation of inorganic CO2 from the external environment. In order to develop technology for the capture of carbon dioxide to reduce greenhouse gases in the atmosphere, enzymes involved in CO2 fixation and assimilation might be very useful. This review describes some current research concerning CO2 fixation and assimilation in the deep sea environment and possible biotechnological application of enzymes for carbon dioxide capture.

  11. Evaluation of functional outcome of pilon fractures managed with limited internal fixation and external fixation: A prospective clinical study.

    Science.gov (United States)

    Meena, Umesh Kumar; Bansal, Mahesh Chand; Behera, Prateek; Upadhyay, Rahul; Gothwal, Gyan Chand

    2017-11-01

    The management of pilon fractures is controversial primarily due to the high rate of complications irrespective of the mode of treatment. Limited internal fixation with external fixation is associated with minimal soft tissue handling. This may reduce the chances of wound dehiscence and infection. This study was designed to evaluate the functional and clinical outcomes in patients treated with limited internal fixation combined with external fixation in pilon fractures. This study was conducted as a prospective clinical study on 56 skeletally mature patients with closed fractures with poor skin condition, and with open grade 1 and grade 2 distal tibial intra-articular fractures. All patients were treated with combined limited internal fixation and ankle spanning external fixation. All fractures in this series united with an average time period of union of 18.3weeks (ranging from 13 weeks to 30 weeks). There was no non-union in any case. There was malunion in 4 cases, varus malunion (>5 degree) in 2 cases and recurvatum in another 2 cases). Excellent to good functional results were observed in 88% cases based on the modified Ovadia and Beals score. The mean ankle dorsiflexion and planter flexion movements were 10.2±5.3 degrees and 27.4±7.2 degrees respectively. infections occurred in 6 patients which included 4 pin tract infections and 2 superficial wound infection, all 6 healed after removal of pin tract and with oral antibiotics. The technique of combined external fixation with internal fixation is safe and effective management option for intra-articular distal tibial fractures.

  12. The importance of regulation of nitrogen fixation

    Science.gov (United States)

    Menge, D. N.

    2012-12-01

    I am not a proponent of including more detail in models simply because it makes them more realistic. More complexity increases the difficulty of model interpretation, so it only makes sense to include complexity if its benefit exceeds its costs. Biological nitrogen (N) fixation (BNF) is one process for which I feel the benefits of including greater complexity far outweigh the costs. I don't think that just because I work on BNF; I work on BNF because I think that. BNF, a microbial process carried out by free-living and symbiotic microbes, is the dominant N input to many ecosystems, the primary mechanism by which N deficiency can feed back to N inputs, and a main mechanism by which N surplus can develop. The dynamics of BNF, therefore, have huge implications for the rate of carbon uptake and the extent of CO2 fertilization, as well as N export to waterways and N2O emissions to the atmosphere. Unfortunately, there are serious deficiencies in our understanding of BNF. One main deficiency in our understanding is the extent to which various symbiotic N fixing organisms respond to imbalanced nutrition. Theory suggests that these responses, which I will call "strategies," have fundamental consequences for N fixer niches and ecosystem-level N and C cycling. Organisms that fix N regardless of whether they need it, a strategy that I will call "obligate," occupy post-disturbance niches and rapidly lead to N surplus. On the contrary, organisms that only fix as much N as they need, a "facultative" strategy, can occupy a wider range of successional niches, do not produce surplus N, and respond more rapidly to increased atmospheric CO2. In this talk I will show new results showing that consideration of these strategies could on its own explain the latitudinal distribution of symbiotic N fixing trees in North America. Specifically, the transition in N-fixing tree abundance from ~10% of basal area south of 35° latitude to ~1% of basal area north of 35° latitude that we observe

  13. Comparison of Monolateral External Fixation and Internal Fixation for Skeletal Stabilisation in the Management of Small Tibial Bone Defects following Successful Treatment of Chronic Osteomyelitis.

    Science.gov (United States)

    Wang, Yicun; Jiang, Hui; Deng, Zhantao; Jin, Jiewen; Meng, Jia; Wang, Jun; Zhao, Jianning; Sun, Guojing; Qian, Hongbo

    2017-01-01

    To compare the salvage rate and complication between internal fixation and external fixation in patients with small bone defects caused by chronic infectious osteomyelitis debridement. 125 patients with chronic infectious osteomyelitis of tibia fracture who underwent multiple irrigation, debridement procedure, and local/systemic antibiotics were enrolled. Bone defects, which were less than 4 cm, were treated with bone grafting using either internal fixation or monolateral external fixation. 12-month follow-up was conducted with an interval of 3 months to evaluate union of bone defect. Patients who underwent monolateral external fixation had higher body mass index and fasting blood glucose, longer time since injury, and larger bone defect compared with internal fixation. No significant difference was observed in incidence of complications (23.5% versus 19.3%), surgery time (156 ± 23 minutes versus 162 ± 21 minutes), and time to union (11.1 ± 3.0 months versus 10.9 ± 3.1 months) between external fixation and internal fixation. Internal fixation had no significant influence on the occurrence of postoperation complications after multivariate adjustment when compared with external fixation. Furthermore, patients who underwent internal fixation experienced higher level of daily living scales and lower level of anxiety. It was relatively safe to use internal fixation for stabilization in osteomyelitis patients whose bone defects were less than 4 cm and infection was well controlled.

  14. High capacity carbon dioxide sorbent

    Science.gov (United States)

    Dietz, Steven Dean; Alptekin, Gokhan; Jayaraman, Ambalavanan

    2015-09-01

    The present invention provides a sorbent for the removal of carbon dioxide from gas streams, comprising: a CO.sub.2 capacity of at least 9 weight percent when measured at 22.degree. C. and 1 atmosphere; an H.sub.2O capacity of at most 15 weight percent when measured at 25.degree. C. and 1 atmosphere; and an isosteric heat of adsorption of from 5 to 8.5 kilocalories per mole of CO.sub.2. The invention also provides a carbon sorbent in a powder, a granular or a pellet form for the removal of carbon dioxide from gas streams, comprising: a carbon content of at least 90 weight percent; a nitrogen content of at least 1 weight percent; an oxygen content of at most 3 weight percent; a BET surface area from 50 to 2600 m.sup.2/g; and a DFT micropore volume from 0.04 to 0.8 cc/g.

  15. Oxygen and carbon dioxide sensing

    Science.gov (United States)

    Ren, Fan (Inventor); Pearton, Stephen John (Inventor)

    2012-01-01

    A high electron mobility transistor (HEMT) capable of performing as a CO.sub.2 or O.sub.2 sensor is disclosed, hi one implementation, a polymer solar cell can be connected to the HEMT for use in an infrared detection system. In a second implementation, a selective recognition layer can be provided on a gate region of the HEMT. For carbon dioxide sensing, the selective recognition layer can be, in one example, PEI/starch. For oxygen sensing, the selective recognition layer can be, in one example, indium zinc oxide (IZO). In one application, the HEMTs can be used for the detection of carbon dioxide and oxygen in exhaled breath or blood.

  16. Carbon dioxide retention in divers

    Energy Technology Data Exchange (ETDEWEB)

    Florio, J.T.; Mackenzie, D.A.R.; McKenzie, R.S. [ARE Physiological Laboratory, Gosport (United Kingdom)

    1998-04-01

    This report summarises the work carried out at the ARE Physiological Laboratory (ARE(PL)) between July 1978 and December 1983. The work was intended to examine the proposition that some divers have a low ventilatory response to carbon dioxide; that this results in a low ventilatory response to exercise with consequent hypercapnia; and that these characteristics put the diver at a greater-than-normal risk by increasing the individual`s susceptibility to oxygen toxicity and to other hazards associated with diving (e.g. nitrogen narcosis, decompression sickness and hypothermia). The specific aims of the project can be summarised as follows: (a) to demonstrate the existence of divers who exhibit the tendency to `retain carbon dioxide` when working in hyperbaric conditions; (b) to define the circumstances under which such individuals are at risk; (c) to assess the magnitude of the risk; and (d) to recommend ways to eliminate or to reduce the risk. (author)

  17. CARBON DIOXIDE AS A FEEDSTOCK.

    Energy Technology Data Exchange (ETDEWEB)

    CREUTZ,C.; FUJITA,E.

    2000-12-09

    This report is an overview on the subject of carbon dioxide as a starting material for organic syntheses of potential commercial interest and the utilization of carbon dioxide as a substrate for fuel production. It draws extensively on literature sources, particularly on the report of a 1999 Workshop on the subject of catalysis in carbon dioxide utilization, but with emphasis on systems of most interest to us. Atmospheric carbon dioxide is an abundant (750 billion tons in atmosphere), but dilute source of carbon (only 0.036 % by volume), so technologies for utilization at the production source are crucial for both sequestration and utilization. Sequestration--such as pumping CO{sub 2} into sea or the earth--is beyond the scope of this report, except where it overlaps utilization, for example in converting CO{sub 2} to polymers. But sequestration dominates current thinking on short term solutions to global warming, as should be clear from reports from this and other workshops. The 3500 million tons estimated to be added to the atmosphere annually at present can be compared to the 110 million tons used to produce chemicals, chiefly urea (75 million tons), salicylic acid, cyclic carbonates and polycarbonates. Increased utilization of CO{sub 2} as a starting material is, however, highly desirable, because it is an inexpensive, non-toxic starting material. There are ongoing efforts to replace phosgene as a starting material. Creation of new materials and markets for them will increase this utilization, producing an increasingly positive, albeit small impact on global CO{sub 2} levels. The other uses of interest are utilization as a solvent and for fuel production and these will be discussed in turn.

  18. Manufacture of uranium dioxide powder

    International Nuclear Information System (INIS)

    Becker, M.

    1976-01-01

    Uranium dioxide powder is prepared by the AUC (ammonium uranyl carbonate) method. Supplementing the known process steps, the AUC, after separation from the mother liquor, is washed with an ammonium hydrogen carbonate or an NH 4 OH solution and is subsequently post-treated with a liquid which reduces the surface tension of the residual water in an AUC. Such a liquid is, for instance, alcohol

  19. Carbon dioxide capture and storage

    International Nuclear Information System (INIS)

    Durand, B.

    2011-01-01

    The author first highlights the reasons why storing carbon dioxide in geological formations could be a solution in the struggle against global warming and climate change. Thus, he comments various evolutions and prospective data about carbon emissions or fossil energy consumption as well as various studies performed by international bodies and agencies which show the interest of carbon dioxide storage. He comments the evolution of CO 2 contributions of different industrial sectors and activities, notably in France. He presents the different storage modes and methods which concern different geological formations (saline aquifers, abandoned oil or gas fields, not exploitable coal seams) and different processes (sorption, carbonation). He discusses the risks associated with these storages, the storable quantities, evokes some existing installations in different countries. He comments different ways to capture carbon dioxide (in post-combustion, through oxy-combustion, by pre-combustion) and briefly evokes some existing installations. He evokes the issue of transport, and discusses efficiency and cost aspects, and finally has few words on legal aspects and social acceptability

  20. Internal friction in uranium dioxide

    International Nuclear Information System (INIS)

    Paulin Filho, Pedro Iris

    1979-01-01

    The uranium dioxide inelastic properties were studied measuring internal friction at low frequencies (of the order of 1 Hz). The work was developed in the 160 to 400 deg C temperature range. The effect of stoichiometry variation was studied oxidizing the sample with consequent change of the defect structure originally present in the non-stoichiometric uranium dioxide. The presence of a wide and irregular peak due to oxidation was observed at low temperatures. Activation energy calculations indicated the occurrence of various relaxation processes and assuming the existence of a peak between - 80 and - 70 deg C , the absolute value obtained for the activation energy (0,54 eV) is consistent with the observed values determined at medium and high frequencies for the stress induced reorientation of defects. The microstructure effect on the inelastic properties was studied for stoichiometric uranium dioxide, by varying grain size and porosity. These parameters have influence on the high temperature measurements of internal friction. The internal friction variation for temperatures higher than 340 deg C is thought to be due to grain boundary relaxation phenomena. (author)

  1. Molecular Pathways

    Science.gov (United States)

    Lok, Benjamin H.; Powell, Simon N.

    2012-01-01

    The Rad52 protein was largely ignored in humans and other mammals when the mouse knockout revealed a largely “no-effect” phenotype. However, using synthetic lethal approaches to investigate context dependent function, new studies have shown that Rad52 plays a key survival role in cells lacking the function of the BRCA1-BRCA2 pathway of homologous recombination. Biochemical studies also showed significant differences between yeast and human Rad52, in which yeast Rad52 can promote strand invasion of RPA-coated single-stranded DNA in the presence of Rad51, but human Rad52 cannot. This results in the paradox of how is human Rad52 providing Rad51 function: presumably there is something missing in the biochemical assays that exists in-vivo, but the nature of this missing factor is currently unknown. Recent studies have suggested that Rad52 provides back-up Rad51 function for all members of the BRCA1-BRCA2 pathway, suggesting that Rad52 may be a target for therapy in BRCA pathway deficient cancers. Screening for ways to inhibit Rad52 would potentially provide a complementary strategy for targeting BRCA-deficient cancers in addition to PARP inhibitors. PMID:23071261

  2. Carbon Dioxide Removal via Passive Thermal Approaches

    Science.gov (United States)

    Lawson, Michael; Hanford, Anthony; Conger, Bruce; Anderson, Molly

    2011-01-01

    A paper describes a regenerable approach to separate carbon dioxide from other cabin gases by means of cooling until the carbon dioxide forms carbon dioxide ice on the walls of the physical device. Currently, NASA space vehicles remove carbon dioxide by reaction with lithium hydroxide (LiOH) or by adsorption to an amine, a zeolite, or other sorbent. Use of lithium hydroxide, though reliable and well-understood, requires significant mass for all but the shortest missions in the form of lithium hydroxide pellets, because the reaction of carbon dioxide with lithium hydroxide is essentially irreversible. This approach is regenerable, uses less power than other historical approaches, and it is almost entirely passive, so it is more economical to operate and potentially maintenance- free for long-duration missions. In carbon dioxide removal mode, this approach passes a bone-dry stream of crew cabin atmospheric gas through a metal channel in thermal contact with a radiator. The radiator is pointed to reject thermal loads only to space. Within the channel, the working stream is cooled to the sublimation temperature of carbon dioxide at the prevailing cabin pressure, leading to formation of carbon dioxide ice on the channel walls. After a prescribed time or accumulation of carbon dioxide ice, for regeneration of the device, the channel is closed off from the crew cabin and the carbon dioxide ice is sublimed and either vented to the environment or accumulated for recovery of oxygen in a fully regenerative life support system.

  3. Optimizing pediatric interdental fixation by use of a paramedian palatal fixation site.

    Science.gov (United States)

    McNichols, Colton H; Hatef, Daniel A; Cole, Patrick D; Hollier, Larry H

    2012-03-01

    Condylar fractures are the most common injury seen in pediatric mandibular trauma. These injuries often cannot be adequately stabilized by conservative techniques such as splinting. The pediatric condyle fracture often requires a period of intermaxillary fixation. Because of the characteristics of the developing dentition, circumdental wiring is often not possible. Surgeons commonly achieve interdental stabilization by the connection of a circum-mandibular wire and a second wire placed through a drill hole in the piriform aperture. This method can be problematic in the young patient whose palatal suture is still patent. In this brief technical note, the use of a paramedian drill hole through the palate posterior to the maxillary incisors is described. It is believed that this method is superior to other techniques because it avoids injury to the deciduous tooth buds and allows for the maxillary wire to be seated in more structurally sound tissues.

  4. [Staple fixation for the treatment of hamate metacarpal joint injury].

    Science.gov (United States)

    Tang, Yang-Hua; Zeng, Lin-Ru; Huang, Zhong-Ming; Yue, Zhen-Shuang; Xin, Da-Wei; Xu, Can-Da

    2014-03-01

    To investigate the effcacy of the staple fixation for the treatment of hamate metacarpal joint injury. From May 2009 to November 2012,16 patients with hamate metacarpal joint injury were treated with staple fixation including 10 males and 6 females with an average age of 33.6 years old ranging from 21 to 57 years. Among them, 11 cases were on the fourth or fifth metacarpal base dislocation without fractures, 5 cases were the fourth or fifth metacarpal base dislocation with avulsion fractures of the back of hamatum. Regular X-ray review was used to observe the fracture healing, joint replacement and position of staple fixation. The function of carpometacarpal joint and metacarpophalangeal joint were evaluated according to ASIA (TAM) system evaluation method. All incision were healed well with no infection. All patients were followed up from 16 to 24 months with an average of (10.0 +/- 2.7) months. No dislocation recurred, the position of internal fixator was good,no broken nail and screw withdrawal were occurred. Five patients with avulsion fracture of the back of hamatum achieved bone healing. The function of carpometacarpal joint and metacarpophalangeal was excellent in 10 cases,good in 5 cases, moderate in 1 case. The application of the staple for the treatment of hamatometacarpal joint injury has the advantages of simple operation, small trauma, reliable fixation, early postoperative function exercise and other advantages, which is the ideal operation mode for hamatometacarpal joint injury.

  5. Relative strength of tailor's bunion osteotomies and fixation techniques.

    Science.gov (United States)

    Haddon, Todd B; LaPointe, Stephan J

    2013-01-01

    A paucity of data is available on the mechanical strength of fifth metatarsal osteotomies. The present study was designed to provide that information. Five osteotomies were mechanically tested to failure using a materials testing machine and compared with an intact fifth metatarsal using a hollow saw bone model with a sample size of 10 for each construct. The osteotomies tested were the distal reverse chevron fixated with a Kirschner wire, the long plantar reverse chevron osteotomy fixated with 2 screws, a mid-diaphyseal sagittal plane osteotomy fixated with 2 screws, the mid-diaphyseal sagittal plane osteotomy fixated with 2 screws, and an additional cerclage wire and a transverse closing wedge osteotomy fixated with a box wire technique. Analysis of variance was performed, resulting in a statistically significant difference among the data at p chevron was statistically the strongest construct at 130 N, followed by the long plantar osteotomy at 78 N. The chevron compared well with the control at 114 N, and they both fractured at the proximal model to fixture interface. The other osteotomies were statistically and significantly weaker than both the chevron and the long plantar constructs, with no statistically significant difference among them at 36, 39, and 48 N. In conclusion, the chevron osteotomy was superior in strength to the sagittal and transverse plane osteotomies and similar in strength and failure to the intact model. Copyright © 2013 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  6. Comparison of cemented and uncemented fixation in total knee arthroplasty.

    Science.gov (United States)

    Brown, Thomas E; Harper, Benjamin L; Bjorgul, Kristian

    2013-05-01

    As a result of reading this article, physicians should be able to :1. Understand the rationale behind using uncemented fixation in total knee arthroplasty.2.Discuss the current literature comparing cemented and uncemented total knee arthroplasty3. Describe the value of radiostereographic analysis in assessing implant stability.4. Appreciate the limitations in the available literature advocating 1 mode of fixation in total knee arthroplasty. Total knee arthroplasty performed worldwide uses either cemented, cementless, or hybrid (cementless femur with a cemented tibia) fixation of the components. No recent literature review concerning the outcomes of cemented vs noncemented components has been performed. Noncemented components offer the potential advantage of a biologic interface between the bone and implants, which could demonstrate the greatest advantage in long-term durable fixation in the follow-up of young patients undergoing arthroplasty. Several advances have been made in the backing of the tibial components that have not been available long enough to yield long-term comparative follow-up studies. Short-term radiostereographic analysis studies have yielded differing results. Although long-term, high-quality studies are still needed, material advances in biologic fixation surfaces, such as trabecular metal and hydroxyapatite, may offer promising results for young and active patients undergoing total knee arthroplasty when compared with traditional cemented options. Copyright 2013, SLACK Incorporated.

  7. Immunohistochemistry of colorectal cancer biomarker phosphorylation requires controlled tissue fixation.

    Directory of Open Access Journals (Sweden)

    Abbey P Theiss

    Full Text Available Phosphorylated signaling molecules are biomarkers of cancer pathophysiology and resistance to therapy, but because phosphoprotein analytes are often labile, poorly controlled clinical laboratory practices could prevent translation of research findings in this area from the bench to the bedside. We therefore compared multiple biomarker and phosphoprotein immunohistochemistry (IHC results in 23 clinical colorectal carcinoma samples after either a novel, rapid tissue fixation protocol or a standard tissue fixation protocol employed by clinical laboratories, and we also investigated the effect of a defined post-operative "cold" ischemia period on these IHC results. We found that a one-hour cold ischemia interval, allowed by ASCO/CAP guidelines for certain cancer biomarker assays, is highly deleterious to certain phosphoprotein analytes, specifically the phosphorylated epidermal growth factor receptor (pEGFR, but shorter ischemic intervals (less than 17 minutes facilitate preservation of phosphoproteins. Second, we found that a rapid 4-hour, two temperature, formalin fixation yielded superior staining in several cases with select markers (pEGFR, pBAD, pAKT compared to a standard overnight room temperature fixation protocol, despite taking less time. These findings indicate that the future research and clinical utilities of phosphoprotein IHC for assessing colorectal carcinoma pathophysiology absolutely depend upon attention to preanalytical factors and rigorously controlled tissue fixation protocols.

  8. Fixation Probability in a Haploid-Diploid Population.

    Science.gov (United States)

    Bessho, Kazuhiro; Otto, Sarah P

    2017-01-01

    Classical population genetic theory generally assumes either a fully haploid or fully diploid life cycle. However, many organisms exhibit more complex life cycles, with both free-living haploid and diploid stages. Here we ask what the probability of fixation is for selected alleles in organisms with haploid-diploid life cycles. We develop a genetic model that considers the population dynamics using both the Moran model and Wright-Fisher model. Applying a branching process approximation, we obtain an accurate fixation probability assuming that the population is large and the net effect of the mutation is beneficial. We also find the diffusion approximation for the fixation probability, which is accurate even in small populations and for deleterious alleles, as long as selection is weak. These fixation probabilities from branching process and diffusion approximations are similar when selection is weak for beneficial mutations that are not fully recessive. In many cases, particularly when one phase predominates, the fixation probability differs substantially for haploid-diploid organisms compared to either fully haploid or diploid species. Copyright © 2017 by the Genetics Society of America.

  9. Fixation orientation in ankle fractures with syndesmosis injury.

    Science.gov (United States)

    Nimick, Craig J; Collman, David R; Lagaay, Pieter

    2013-01-01

    Accurate reduction of the syndesmosis has been shown to be an important prognostic factor for functional outcome in ankle injuries that disrupt the syndesmosis. The purpose of the present case series was to assess the fixation orientation and the position of the fibula within the tibial incisura after open reduction and internal fixation of ankle fractures with syndesmosis injury. Computed tomography was used to assess the accuracy of the reduction. Twelve patients were included in the present case series. A ratio representing the relationship between the tibia and fibula and the orientation of the syndesmotic fixation was measured preoperatively and postoperatively and compared with the uninjured contralateral ankle, representing the patient's normal anatomy. The measurements were accomplished electronically to one tenth of 1 mm using Stentor Intelligent Informatics, I-site, version 3.3.1 (Phillips Electronics; Andover, MA). Posteriorly oriented syndesmotic fixation caused posterior translation of the fibula with respect to the tibia and anteriorly oriented syndesmotic fixation caused anterior translation. Copyright © 2013. Published by Elsevier Inc.

  10. CROP YIELD AND CO2 FIXATION MONITORING IN ASIA USING A PHOTOSYNTHETICSTERILITY MODEL WITH SATELLITES AND METEOROLOGICAL DATA

    Energy Technology Data Exchange (ETDEWEB)

    Daijiro Kaneko [Department of Civil and Environmental Engineering, Matsue National College of Technology, Matsue (Japan); Toshiro Kumakura [Department of Civil and Environmental Engineering, Nagaoka University of Technology, Nagaoka (Japan); Peng Yang [Laboratory of Resources Remote Sensing and Digital Agriculture, Ministry of Agriculture, Beijing (China)

    2008-09-30

    This study is intended to develop a model for estimating carbon dioxide (CO{sub 2}) fixation in the carbon cycle and for monitoring grain yields using a photosynthetic-sterility model, which integrates solar radiation and air temperature effects on photosynthesis, along with grain-filling from heading to ripening. Grain production monitoring would support orderly crisis management to maintain food security in Asia, which is facing climate fluctuation through this century of global warming. The author improved a photosynthesis-and-sterility model to compute both the crop yield and crop situation index CSI, which gives a percentage of rice yields compared to normal annual production. The model calculates photosynthesis rates including biomass effects, lowtemperature sterility, and high-temperature injury by incorporating solar radiation, effective air temperature, the normalized difference vegetation index NDVI, and the effect of temperature on photosynthesis by grain plant leaves. A decision-tree method classifies the distribution of crop fields in Asia using MODIS fundamental landcover and SPOT VEGETATION data, which include the Normalized Vegetation index (NDVI) and Land Surface Water Index (LSWI). This study provides daily distributions of the photosynthesis rate, which is the CO2 fixation in Asian areas combined with the land-cover distribution, the Japanese geostationary meteorological satellite (GMS), and meteorological re-analysis data by National Centers for Environmental Prediction (NCEP). The method is based on routine observation data, enabling automated monitoring of crop yields.

  11. Absorption of carbon dioxide in waste tanks

    International Nuclear Information System (INIS)

    Hobbs, D.T.

    1987-01-01

    Air flow rates and carbon dioxide concentrations of air entering and exiting eight H-Area waste tanks were monitored for a period of one year. The average instanteous concentration of carbon dioxide in air is within the range reported offsite, and therefore is not affect by operation of the coal-fired power plant adjacent to the tank farm. Waste solutions in each of the tanks were observed to be continuously absorbing carbon dioxide. The rate of absorption of carbon dioxide decreased linearly with the pH of the solution. Personnel exposure associated with the routine sampling and analysis of radioactive wastes stored at SRP to determine the levels of corrosion inhibitors in solution could be reduced by monitoring the absorption of carbon dioxide and using the relationship between pH and carbon dioxide absorption to determine the free hydroxide concentration in solution

  12. Pediatric mandibular fractures treated by rigid internal fixation.

    Science.gov (United States)

    Wong, G B

    1993-09-01

    Mandibular fractures in the pediatric patient population are relatively uncommon. These patients present with their own unique treatment requirements. Most fractures have been treated conservatively by dental splints. Closed reduction techniques with maxillomandibular fixation (MMF) in very young children can pose several concerns, including cooperation, compliance and adequate nutritional intake. Rigid internal fixation of unstable mandibular fractures using miniplates and screws circumvents the need for MMF and allows immediate jaw mobilization. At major pediatric trauma institutions, there has been an increasing trend toward the use of this treatment when open reduction is necessary. This article presents a report of a five-year-old child who presented with bilateral mandibular fractures and was treated by rigid internal fixation and immediate mandibular mobilization.

  13. Buckminsterfullerenes: a non-metal system for nitrogen fixation.

    Science.gov (United States)

    Nishibayashi, Yoshiaki; Saito, Makoto; Uemura, Sakae; Takekuma, Shin-Ichi; Takekuma, Hideko; Yoshida, Zen-Ichi

    2004-03-18

    In all nitrogen-fixation processes known so far--including the industrial Haber-Bosch process, biological fixation by nitrogenase enzymes and previously described homogeneous synthetic systems--the direct transformation of the stable, inert dinitrogen molecule (N2) into ammonia (NH3) relies on the powerful redox properties of metals. Here we show that nitrogen fixation can also be achieved by using a non-metallic buckminsterfullerene (C60) molecule, in the form of a water-soluble C60:gamma-cyclodextrin (1:2) complex, and light under nitrogen at atmospheric pressure. This metal-free system efficiently fixes nitrogen under mild conditions by making use of the redox properties of the fullerene derivative.

  14. Operative Fixation of Rib Fractures Indications, Techniques, and Outcomes.

    Science.gov (United States)

    Galos, David; Taylor, Benjamin; McLaurin, Toni

    2017-01-01

    Rib fractures are extremely common injuries and vary in there severity from single nondisplaced fractures to multiple segmental fractures resulting in flail chest and respiratory compromise. Historically, rib fractures have been treated conservatively with pain control and respiratory therapy. However this method may not be the best treatment modality in all situations. Operative fixation of select rib fractures has been increasing in popularity especially in patients with flail chest and respiratory compromise. Newer techniques use muscle sparing approaches and precontoured locking plate technology to obtain stable fixation and allow improved respiration. Current reports shows that rib fracture fixation offers the benefits of improved respiratory mechanics and improved pain control in the severe chest wall injury with resultant improvement in patient outcomes by decreasing time on the ventilator, time in the intensive care unit, and overall hospital length of stay.

  15. Single absorbable polydioxanone pin fixation for distal chevron bunion osteotomies.

    Science.gov (United States)

    Deorio, J K; Ware, A W

    2001-10-01

    The distal chevron osteotomy is a well-established technique for correction of symptomatic mild to moderate metatarsus primus varus with hallux valgus deformity. Fixation of the osteotomy ranges from none to bone pegs, Kirschner wires, screws, or absorbable pins. We evaluated one surgeon's (J.K.D.) results of distal chevron osteotomy fixation with a single, nonpredrilled, 1.3-mm poly-p-dioxanone pin and analyzed any differences in patients with unilateral or bilateral symptomatic metatarsus primus varus with hallux valgus deformities. All osteotomies healed without evidence of infection, osteolysis, nonunion, or necrosis. Equal correction was achieved in unilateral and bilateral procedures. The technique is quick and easy, and adequate fixation is achieved.

  16. Can we improve fixation and outcomes? Use of bone substitutes.

    Science.gov (United States)

    Moroni, Antonio; Larsson, Sune; Hoang Kim, Amy; Gelsomini, Letizia; Giannoudis, Peter V

    2009-07-01

    Hip fractures secondary to osteoporosis are common in the elderly. Stabilizing these fractures until union is achieved is a challenge due to poor bone stock and insufficient purchase of the implant to the bone. The reported high rate of complications has prompted extensive research in the development of fixation techniques. Furthermore, manipulation of both the local fracture environment in terms of application of growth factors, scaffolds, and mesenchymal cells and the systemic administration of agents promoting bone formation and bone strength has been considered as a treatment option with promising results. There are only a few evidence-based studies reporting on fixation augmentation techniques. This article reports on the efficacy of bone graft substitutes for the fixation of hip fractures, in particular calcium phosphates, which have been used as granules, cements, and implant coatings.

  17. How Life History Can Sway the Fixation Probability of Mutants

    Science.gov (United States)

    Li, Xiang-Yi; Kurokawa, Shun; Giaimo, Stefano; Traulsen, Arne

    2016-01-01

    In this work, we study the effects of demographic structure on evolutionary dynamics when selection acts on reproduction, survival, or both. In contrast to the previously discovered pattern that the fixation probability of a neutral mutant decreases while the population becomes younger, we show that a mutant with a constant selective advantage may have a maximum or a minimum of the fixation probability in populations with an intermediate fraction of young individuals. This highlights the importance of life history and demographic structure in studying evolutionary dynamics. We also illustrate the fundamental differences between selection on reproduction and selection on survival when age structure is present. In addition, we evaluate the relative importance of size and structure of the population in determining the fixation probability of the mutant. Our work lays the foundation for also studying density- and frequency-dependent effects in populations when demographic structures cannot be neglected. PMID:27129737

  18. Photosynthetic and nitrogen fixation capability in several soybean mutant lines

    International Nuclear Information System (INIS)

    Gandanegara, S.; Hendratno, K.

    1987-01-01

    Photosynthetic and nitrogen fixation capability in several soybean mutant lines. A greenhouse experiment has been carried out to study photosynthetic and nitrogen fixation capability of five mutant lines and two soybean varieties. An amount of 330 uCi of 14 CO 2 was fed to the plants including of the non-fixing reference crop (Chippewa non-nodulating isoline). Nitrogen fixation measurements was carried out using 15 N isotope dilution technique according to A-value concept. Results showed that beside variety/mutant lines, plant growth also has important role in photosynthetic and N fixing capability. Better growth and a higher photosynthetic capability in Orba, mutant lines nos. 63 and 65 resulted in a greater amount of N 2 fixed (mg N/plant) than other mutant lines. (author). 12 refs.; 5 figs

  19. 21 CFR 184.1240 - Carbon dioxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Carbon dioxide. 184.1240 Section 184.1240 Food and... Substances Affirmed as GRAS § 184.1240 Carbon dioxide. (a) Carbon dioxide (empirical formula CO2, CAS Reg. No.... The solid form, dry ice, sublimes under atmospheric pressure at a temperature of −78.5 °C. Carbon...

  20. A METHOD OF PREPARING URANIUM DIOXIDE

    Science.gov (United States)

    Scott, F.A.; Mudge, L.K.

    1963-12-17

    A process of purifying raw, in particular plutonium- and fission- products-containing, uranium dioxide is described. The uranium dioxide is dissolved in a molten chloride mixture containing potassium chloride plus sodium, lithium, magnesium, or lead chloride under anhydrous conditions; an electric current and a chlorinating gas are passed through the mixture whereby pure uranium dioxide is deposited on and at the same time partially redissolved from the cathode. (AEC)

  1. Biomechanical Strength of Retrograde Fixation in Proximal Third Scaphoid Fractures.

    Science.gov (United States)

    Daly, Charles A; Boden, Allison L; Hutton, William C; Gottschalk, Michael B

    2018-04-01

    Current techniques for fixation of proximal pole scaphoid fractures utilize antegrade fixation via a dorsal approach endangering the delicate vascular supply of the dorsal scaphoid. Volar and dorsal approaches demonstrate equivalent clinical outcomes in scaphoid wrist fractures, but no study has evaluated the biomechanical strength for fractures of the proximal pole. This study compares biomechanical strength of antegrade and retrograde fixation for fractures of the proximal pole of the scaphoid. A simulated proximal pole scaphoid fracture was produced in 22 matched cadaveric scaphoids, which were then assigned randomly to either antegrade or retrograde fixation with a cannulated headless compression screw. Cyclic loading and load to failure testing were performed and screw length, number of cycles, and maximum load sustained were recorded. There were no significant differences in average screw length (25.5 mm vs 25.6 mm, P = .934), average number of cyclic loading cycles (3738 vs 3847, P = .552), average load to failure (348 N vs 371 N, P = .357), and number of catastrophic failures observed between the antegrade and retrograde fixation groups (3 in each). Practical equivalence between the 2 groups was calculated and the 2 groups were demonstrated to be practically equivalent (upper threshold P = .010). For this model of proximal pole scaphoid wrist fractures, antegrade and retrograde screw configuration have been proven to be equivalent in terms of biomechanical strength. With further clinical study, we hope surgeons will be able to make their decision for fixation technique based on approaches to bone grafting, concern for tenuous blood supply, and surgeon preference without fear of poor biomechanical properties.

  2. Internal fixation of mandibular angle fractures: a meta-analysis.

    Science.gov (United States)

    Regev, Eran; Shiff, Jacob S; Kiss, Alex; Fialkov, Jeffrey A

    2010-06-01

    The degree of rigidity of internal fixation required for the treatment of mandibular angle fractures has long been at the center of debate in the literature. A statistical comparison between rigid fixation and monocortical fixation has been difficult because of multiple terms, definitions, and technical variations. The purpose of this study was to use the meta-analysis tool to combine information from multiple studies and to compare complication rates for different fixation methods. An English language literature search was conducted for articles on mandibular angle fractures. Information was collected on four variables of interest: compression/noncompression technique, monocortical/bicortical screws, number of plates, and location of plates. Five outcome rates were analyzed: infection, reoperation, hardware removal, malunion, and nonunion. Meta-analyses were run using Comprehensive Meta Analysis, version 2.2.03. Twenty-four studies with relevant data on the variables and outcomes of interest met the inclusion criteria. Significantly higher rates of infection, reoperation, and hardware removal were found for compression compared with noncompression, two plates compared with one plate, and for plates located on both the inferior and superior borders as compared with superior or inferior only. There were also significantly higher infection rates for bicortical screws compared with monocortical screws and higher malunion rates for compression compared with noncompression plating techniques. The results of this meta-analysis found lower complication rates with the use of noncompression, monocortical, and single-plate fixation, supporting the trend toward a single, superiorly placed, monocortical miniplate for fixation of mandibular angle fractures.

  3. Fixations on objects in natural scenes: dissociating importance from salience

    Directory of Open Access Journals (Sweden)

    Bernard Marius e’t Hart

    2013-07-01

    Full Text Available The relation of selective attention to understanding of natural scenes has been subject to intense behavioral research and computational modeling, and gaze is often used as a proxy for such attention. The probability of an image region to be fixated typically correlates with its contrast. However, this relation does not imply a causal role of contrast. Rather, contrast may relate to an object’s importance for a scene, which in turn drives attention. Here we operationalize importance by the probability that an observer names the object as characteristic for a scene. We modify luminance contrast of either a frequently named (common/important or a rarely named (rare/unimportant object, track the observers’ eye movements during scene viewing and ask them to provide keywords describing the scene immediately after.When no object is modified relative to the background, important objects draw more fixations than unimportant ones. Increases of contrast make an object more likely to be fixated, irrespective of whether it was important for the original scene, while decreases in contrast have little effect on fixations. Any contrast modification makes originally unimportant objects more important for the scene. Finally, important objects are fixated more centrally than unimportant objects, irrespective of contrast.Our data suggest a dissociation between object importance (relevance for the scene and salience (relevance for attention. If an object obeys natural scene statistics, important objects are also salient. However, when natural scene statistics are violated, importance and salience are differentially affected. Object salience is modulated by the expectation about object properties (e.g., formed by context or gist, and importance by the violation of such expectations. In addition, the dependence of fixated locations within an object on the object’s importance suggests an analogy to the effects of word frequency on landing positions in reading.

  4. Preliminary experience with biodegradable implants for fracture fixation

    Directory of Open Access Journals (Sweden)

    Dhillon Mandeep

    2008-01-01

    Full Text Available Background: Biodegradable implants were designed to overcome the disadvantages of metal-based internal fixation devices. Although they have been in use for four decades internationally, many surgeons in India continue to be skeptical about the mechanical strength of biodegradable implants, hence this study. Materials and Methods: A prospective study was done to assess the feasibility and surgeon confidence level with biodegradable implants over a 12-month period in an Indian hospital. Fifteen fractures (intra-articular, metaphyseal or small bone fractures were fixed with biodegradable implants. The surgeries were randomly scheduled so that different surgeons with different levels of experience could use the implants for fixation. Results: Three fractures (one humeral condyle, two capitulum, were supplemented by additional K-wires fixation. Trans-articular fixator was applied in two distal radius and two pilon fractures where bio-pins alone were used. All fractures united, but in two cases the fracture displaced partially during the healing phase; one fibula due to early walking, and one radius was deemed unstable even after bio-pin and external fixator. Conclusions: Biodegradable -implants are excellent for carefully selected cases of intra-articular fractures and some small bone fractures. However, limitations for use in long bone fractures persist and no great advantage is gained if a "hybrid" composite is employed. The mechanical properties of biopins and screws in isolation are perceived to be inferior to those of conventional metal implants, leading to low confidence levels regarding the stability of reduced fractures; these implants should be used predominantly in fracture patterns in which internal fixation is subjected to minimal stress.

  5. Combined effect of sulfur dioxide and carbon dioxide gases on mold fungi

    Energy Technology Data Exchange (ETDEWEB)

    Kochurova, A.I.; Karpova, T.N.

    1974-01-01

    Sulfur dioxide at 0.08% killed Penicillium expansum, Stemphylium macrosporium, and Botrytis cinerea within 24 hours. At 0.2%, it killed P. citrinum, Alternaria tenuis, and Fusarium moniliforme. Sulfur dioxide (at 0.04%) and Sulfur dioxide-carbon dioxide mixtures (at 0.02 and 5% respectively) completely suppressed the growth of P. citrinum, P. expansum, P. rubrum, A. tenuis, S. macrosporium, B. cinerea, and F. moniliforme in laboratory experiments. 1 table.

  6. Experimental nitrogen dioxide poisoning in cattle

    Energy Technology Data Exchange (ETDEWEB)

    Cutlip, R C

    1966-01-01

    Experimental nitrogen dioxide inhalation has been reported to produce signs and lesions typical of field cases of bovine pulmonary adenomatosis (BPA) as described by Monlux et al, and Seaton. Similar lesions have been produced in mice and guinea pigs. These studies were conducted because of the similarities between silo-filler's disease of man, caused by nitrogen dioxide, and BPA. Since previous studies involved inadequate numbers of cattle, a more critical evaluation of the effects of nitrogen dioxide was needed. This project was designed to study the clinical and pathologic alterations induced in cattle by repeated exposure to nitrogen dioxide gas.

  7. Soaking morselized allograft in bisphosphonate can impair implant fixation

    DEFF Research Database (Denmark)

    Jakobsen, Thomas; Baas, Jørgen; Bechtold, Joan E

    2007-01-01

    biomechanical implant fixation and graft incorporation. In 10 dogs, a pair of titanium implants surrounded by a 2.5-mm gap was inserted into the proximal part of each humerus during two separate surgeries to allow two observation periods. The gap was filled with impacted, morselized allograft soaked in either...... of implants was observed for 12 weeks and the second pair for 4 weeks. Implants were evaluated by histomorphometry and biomechanical pushout test. We found substantially decreased biomechanical implant fixation for all implants surrounded by impacted, morselized allograft that had been soaked in alendronate...

  8. [Usefullness of intrasacral fixation in an extremely unstable lumbosacral spine].

    Science.gov (United States)

    Nishiura, Tsukasa; Nishiguchi, Mitsuhisa; Kusaka, Noboru; Takayama, Kazuhiro; Maeda, Yasuhiko; Ogihara, Kotaro; Nakagawa, Minoru

    2007-04-01

    Intrasacral fixation technique devised by Jackson is said to provide rigid lumbosacral fixation. We treated 3 cases of lumbosacral lesions using this technique in which lumbosacral segment had become extremely unstable during surgical intervention adding to the effect of original lesions. In all cases, surgeries were performed in 2 stages, intrasacral fixation and anterior stabilization. Case 1: A 52-year-old male was diagnosed fungal discitis and spondylitis at L4 and L5. X-ray showed destruction of the vertebral bodies. L2, L3 and sacrum were fixed posteriorly using the intrasacral fixation technique. One week after the first operation, L4 and L5 vertebral bodies were replaced by long fibula grafts through the extraperitoneal approach. Case 2: A 25-year-old female with cauda equina syndrome and abnormal body form diagnosed as having spondyloptosis in which the entire vertebral body of L5 had descended below the endplate of S1. MR imaging revealed marked canal stenosis at the S1 level. In the first surgery, L5 vertebral body was resected through the transperitoneal approach. After 1 week of bed rest, posterior segments of L5 were resected, L4 was affixed to the sacrum and anterior stabilization was achieved with 2 mesh cages and lumbosacral spine was fixed using the intrasacral fixation technique. Case 3: A 64-year-old female was diagnosed as having pyogenic discitis and osteomyelitis at the L5-S1 level. In spite of successful medical treatment for infection, low back pain continued. Radiologically, L5 vertebral body was shown to have collapsed and slipped anteriorly over the sacrum. L3, L4 and sacrum were fixed by intrasacral fixation. One week after the first operation, the L5/S1 disc and the suppurtive vertebral bodies were resected through the extraperitoneal approach and anterior stabilization was performed with iliac bone grafts. At follow-up for a minimum of 6 months, initial fixation was maintained in all 3 cases and bony fusion was obtained. The

  9. The use of titanium and stainless steel in fracture fixation.

    Science.gov (United States)

    Hayes, J S; Richards, R G

    2010-11-01

    The use of metal in fracture fixation has demonstrated unrivalled success for many years owing to its high stiffness, strength, biological toleration and overall reliable function. The most prominent materials used are electropolished stainless steel and commercially pure titanium, along with the more recent emergence of titanium alloys. Despite the many differences between electropolished stainless steel and titanium, both materials provide a relatively predictable clinical outcome, and offer similar success for fulfilling the main biomechanical and biological requirements of fracture fixation despite distinctive differences in implant properties and biological responses. This article explores these differences by highlighting the limitations and advantages of both materials, and addresses how this translates to clinical success.

  10. Titanium dioxide nanomaterials for photocatalysis

    International Nuclear Information System (INIS)

    Liu, Yan; Li, Zhe; Green, Michael; Just, Michael; Chen, Xiaobo; Li, Yang Yang

    2017-01-01

    Titanium dioxide (TiO 2 ) has been long regarded as one of the more promising photocatalysts to remove environmental pollution and to generate hydrogen from water under sunlight irradiation via photocatalysis. TiO 2 is environmentally benign and thus is considered a ‘green’ catalyst. In this review we present a short introduction to the physical and electronic properties of TiO 2 , its photocatalytic mechanisms, and some recent examples of various TiO 2 materials used for photocatalysis; these examples include 0, 1, 2, 3D, faceted, defected, composited, and hydrogenated TiO 2 materials. (topical review)

  11. Muon transfer to sulphur dioxide

    International Nuclear Information System (INIS)

    Mulhauser, F.; Schneuwly, H.

    1993-01-01

    A systematic study of muon capture and muon transfer has been performed in seven different H 2 + SO 2 gas mixtures. From the single-exponential time structure of the muonic sulphur x-rays, one determines the lifetime of the μp atoms under the given experimental conditions. The reduced muon transfer rates to the sulphur dioxide molecule, deduced from these lifetimes, all agree well with each other. The muonic oxygen time spectra show an additional structure as if μp atoms of another kind were present. Comparable time structures are observed in a D 2 + SO 2 mixture. (author)

  12. Modified fixation with pinning and external fixation components for feline femur multiple-lined fracture: A case report

    International Nuclear Information System (INIS)

    Okamoto, Y.; Minami, S.; Matuhashi, A.

    1992-01-01

    A 3-year-old female Japanese domestic cat, weighing 3kg, was referred to us because of right hind leg lameness occuring for 3 days' duration. Radiography of the affected leg revealed severe femoral diaphysial comminuted fracture. The affected leg was treated using wire with an intramedullary Stainman pin being placed completely through the femur. After suturing the wound, both ends of the intramedullary pin exposed both proximally and distally were fixed with external fixation components (two double clamps, two single clamps, two short rods and one long rod) to prevent the pin from rotation. There was a slight gait problem due to the external apparatus and no post-operative infection. The function of the right hind leg gradually recovered. The intramedullary pin and external fixative apparatus were removed on the 52nd day after surgery. This modified fixation appears to offer versatility in the treatment of various fractures in smaller dogs and cats

  13. Comparative study of thyroid fixation of different iodine compounds; Etude comparative de la fixation thyroidienne de differents composes iodes

    Energy Technology Data Exchange (ETDEWEB)

    Rinaldi, R; Coeur, A; Raynfeld, Ch [Commissariat a l' Energie Atomique, Grenoble (France).Centre d' Etudes Nucleaires

    1961-07-01

    The aim of this work is to study the thyroid fixation of various iodine compounds in mineral or organic form. The animals (rats) are given therapeutic doses of the derivative orally with the object of saturating the thyroid, and then receive a determined dose of radio-iodine 131 by intra-peritoneal injection; any fixation of this latter is then measured under anaesthetic by means of a scintillation counter. Whatever form of iodine derivative was used whether in ionic (potassium iodide type) or organic form (iodo-tannic syrup) or in the form of elementary iodine (iodinated water), thyroid saturation was always obtained, as shown by practically zero fixation of the 4 {mu}curies of iodine 131 administered by intra-peritoneal injection. (author) [French] Notre travail a pour but l'etude de la fixation thyroidienne de differents composes iodes sous forme minerale ou organique. Les animaux (rats), apres absorption orale de doses therapeutiques de derives destines a saturer leur thyroide recoivent par voie intra-peritoneale une dose determinee de radio-iode {sup 131}I, la fixation eventuelle de ce dernier est ensuite mesuree sous anesthesie en utilisant un compteur a scintillation. Quelle que soit la forme utilisee, c'est-a-dire derive iode sous forme ionique (type iodure de potassium) ou sous forme organique (sirop iodotanique) ou encore sous forme d'iode metalloidique (eau iodee), nous avons obtenu chaque fois une saturation thyroidienne mise en evidence par une fixation pratiquement nulle des 4 {mu}curies de l'iode 131 injectes par voie intraperitoneale. (auteur)

  14. A cell shrinkage artefact in growth plate chondrocytes with common fixative solutions: importance of fixative osmolarity for maintaining morphology

    Directory of Open Access Journals (Sweden)

    MY Loqman

    2010-05-01

    Full Text Available The remarkable increase in chondrocyte volume is a major determinant in the longitudinal growth of mammalian bones. To permit a detailed morphological study of hypertrophic chondrocytes using standard histological techniques, the preservation of normal chondrocyte morphology is essential. We noticed that during fixation of growth plates with conventional fixative solutions, there was a marked morphological (shrinkage artifact, and we postulated that this arose from the hyper-osmotic nature of these solutions. To test this, we fixed proximal tibia growth plates of 7-day-old rat bones in either (a paraformaldehyde (PFA; 4%, (b glutaraldehyde (GA; 2% with PFA (2% with ruthenium hexamine trichloride (RHT; 0.7%, (c GA (2% with RHT (0.7%, or (d GA (1.3% with RHT (0.5% and osmolarity adjusted to a ‘physiological’ level of ~280mOsm. Using conventional histological methods, confocal microscopy, and image analysis on fluorescently-labelled fixed and living chondrocytes, we then quantified the extent of cell shrinkage and volume change. Our data showed that the high osmolarity of conventional fixatives caused a shrinkage artefact to chondrocytes. This was particularly evident when whole bones were fixed, but could be markedly reduced if bones were sagittally bisected prior to fixation. The shrinkage artefact could be avoided by adjusting the osmolarity of the fixatives to the osmotic pressure of normal extracellular fluids (~280mOsm. These results emphasize the importance of fixative osmolarity, in order to accurately preserve the normal volume/morphology of cells within tissues.

  15. Novel Pathway for Alcoholic Fermentation of 8-Gluconolactone in the Yeast Saccharomyces bulderi

    NARCIS (Netherlands)

    Dijken, van J.P.; Tuijl, van A.; Luttik, M.A.H.; Middelhoven, W.J.; Pronk, J.T.

    2002-01-01

    Under anaerobic conditions, the yeast Saccharomyces bulderi rapidly ferments -gluconolactone to ethanol and carbon dioxide. We propose that a novel pathway for -gluconolactone fermentation operates in this yeast. In this pathway, -gluconolactone is first reduced to glucose via an NADPH-dependent

  16. A financial analysis of maxillomandibular fixation versus rigid internal fixation for treatment of mandibular fractures.

    Science.gov (United States)

    Schmidt, B L; Kearns, G; Gordon, N; Kaban, L B

    2000-11-01

    The aim of this study was to compare the cost-effectiveness of mandibular fracture treatment by closed reduction with maxillomandibular fixation (CRF) with open reduction and rigid internal fixation (ORIF). This was a retrospective study of 85 patients admitted to the Oral and Maxillofacial Surgery Service at San Francisco General Hospital and treated for mandibular fractures from January 1 to December 31, 1993. The patients were divided into 2 groups: 1) those treated with CRF and 2) those treated with ORIF. The outcome variables were length of hospital stay, duration of anesthesia, and time in operating room. The charge for primary fracture treatment included the fees for the operation and hospitalization without any complications. Within the group of 85 patients treated for mandibular fractures in 1993, 10 patients treated with CRF and 10 patients treated with ORIF were randomly selected, and hospital billing statements were used to estimate the average charge of primary treatment. The average charge to manage a major postoperative infection also was estimated based on the billing statements of 10 randomly selected patients treated in 1992 (5 treated with CRF, 5 with ORIF) who required hospital admission for the management of a complication. The average total charge was computed by using the average charge for primary treatment plus the incidence of postoperative infection multiplied by the average charge for management of that complication. Eighty-five patients were included in the study. The average charge for primary treatment was $10,100 for the CRF group and $28,362 for the ORIF group. The average charge for the inpatient management of a major postoperative infection was $26,671 for the CRF group and $39,213 for the ORIF group. The average total charge for management of a mandible fracture with CRF was $10,927; the total charge for the ORIF group was $34,636. The results of this retrospective study suggest that the use of CRF in the management of mandibular

  17. Short Segment Fixation Versus Short Segment Fixation With Pedicle Screws at the Fracture Level for Thoracolumbar Burst Fracture

    Directory of Open Access Journals (Sweden)

    Anghel S

    2014-04-01

    Full Text Available Objective: The most prevailing surgical procedure in the treatment of thoracolumbar burst fractures, Short Segment Fixation (SSF, is often followed by loss of correction or hardware failure which may be significant enough to require another surgical intervention. In order to take advantage of its benefits but to avoid or diminish the risk and impact of associated drawbacks, some other alternatives have been lately developed among which we refer to short segment fixation with intermediate screws (SSF+IS. This article provides a comparative picture over the effectiveness of the two above-mentioned surgical treatments, focusing on their potential to prevent the loss of correction.

  18. Sulfur Dioxide Analyzer Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Springston, Stephen R. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-05-01

    The Sulfur Dioxide Analyzer measures sulfur dioxide based on absorbance of UV light at one wavelength by SO2 molecules which then decay to a lower energy state by emitting UV light at a longer wavelength. Specifically, SO2 + hυ1 →SO2 *→SO2 + hυ2 The emitted light is proportional to the concentration of SO2 in the optical cell. External communication with the analyzer is available through an Ethernet port configured through the instrument network of the AOS systems. The Model 43i-TLE is part of the i-series of Thermo Scientific instruments. The i-series instruments are designed to interface with external computers through the proprietary Thermo Scientific iPort Software. However, this software is somewhat cumbersome and inflexible. Brookhaven National Laboratory (BNL) has written an interface program in National Instruments LabView that both controls the Model 43i-TLE Analyzer AND queries the unit for all measurement and housekeeping data. The LabView vi (the software program written by BNL) ingests all raw data from the instrument and outputs raw data files in a uniform data format similar to other instruments in the AOS and described more fully in Section 6.0 below.

  19. Impact of Crab Bioturbation on Nitrogen-Fixation Rates in Red Sea Mangrove Sediment

    KAUST Repository

    Qashqari, Maryam S.

    2017-01-01

    be uptaken by plants. Hence, biological nitrogen fixation increases the input of nitrogen in the mangrove ecosystem. In this project, we focus on measuring the rates of nitrogen fixation on Red Sea mangrove (Avicennia marina) located at Thuwal, Saudi Arabia

  20. Stress and stability of plate-screw fixation and screw fixation in the treatment of Schatzker type IV medial tibial plateau fracture: a comparative finite element study.

    Science.gov (United States)

    Huang, Xiaowei; Zhi, Zhongzheng; Yu, Baoqing; Chen, Fancheng

    2015-11-25

    The purpose of this study is to compare the stress and stability of plate-screw fixation and screw fixation in the treatment of Schatzker type IV medial tibial plateau fracture. A three-dimensional (3D) finite element model of the medial tibial plateau fracture (Schatzker type IV fracture) was created. An axial force of 2500 N with a distribution of 60% to the medial compartment was applied to simulate the axial compressive load on an adult knee during single-limb stance. The equivalent von Mises stress, displacement of the model relative to the distal tibia, and displacement of the implants were used as the output measures. The mean stress value of the plate-screw fixation system was 18.78 MPa, which was significantly (P stress value of the triangular fragment in the plate-screw fixation system model was 42.04 MPa, which was higher than that in the screw fixation model (24.18 MPa). But the mean stress of the triangular fractured fragment in the screw fixation model was significantly higher in terms of equivalent von Mises stress (EVMS), x-axis, and z-axis (P < 0.001). This study demonstrated that the load transmission mechanism between plate-screw fixation system and screw fixation system was different and the stability provided by the plate-screw fixation system was superior to the screw fixation system.

  1. [Long-term efficacy of open reduction and internal fixation versus external fixation for unstable distal radius fractures: a meta-analysis].

    Science.gov (United States)

    Yang, Z; Yuan, Z Z; Ma, J X; Ma, X L

    2017-11-07

    Objective: To make a systematic assessment of the Long-term efficacy of open reduction and internal fixation versus external fixation for unstable distal radius fractures. Methods: A computer-based online search of PubMed, ScienceDirect, EMBASE, BIOSIS, Springer and Cochrane Library were performed. The randomized and controlled trials of open reduction and internal fixation versus external fixation for unstable distal radius fractures were collected. The included trials were screened out strictly based on the criterion of inclusion and exclusion. The quality of included trials was evaluated. RevMan 5.0 was used for data analysis. Results: Sixteen studies involving 1 268 patients were included. There were 618 patients with open reduction and internal fixation and 650 with external fixation. The results of meta-analysis indicated that there were statistically significant differences with regard to the complications postoperatively (infection( I (2)=0%, RR =0.27, 95% CI 0.16-0.45, Z =4.92, P internal fixation and external fixation are effective treatment for unstable distal radius fractures. Compared with external fixation, open reduction and internal fixation provides reduced complications postoperatively, lower DASH scores and better restoration of volar tilt for treatment of distal radius fractures.

  2. Percutaneous Pin Fixation of Gartland Type I11 Supraconylar ...

    African Journals Online (AJOL)

    S G Lungu M.Med (Orth). Specialist Orthopaedic Surgeon. Zambian Italian Orthopaedic Hospital, Lusaka. Key words: Percutaneous, pin fixation, Gartland type Ill, supracondylar, fractures, and humerus. This was a prospective study of 40 children with severely displaced (Gartland Type 111) supracondylar fractures of the ...

  3. Nitrogen fixation and nodulation of soybean as affected by rhizobial ...

    African Journals Online (AJOL)

    The study evaluated the efficacy of different adhesives added to rhizobial seed inoculum on soybean nodulation and biological nitrogen fixation in a screen house and under field conditions. The experiment was a 6×3 factorial arranged in Completely Randomized Design and Randomized Complete Block Design for the pot ...

  4. Breeding for traits supportive of nitrogen fixation in legumes

    International Nuclear Information System (INIS)

    Herridge, David F.

    2001-01-01

    As the potential economic benefits of enhancing dinitrogen (N 2 ) fixation of crop, pasture and forage legumes are substantial, the idea that legume breeding could play a role in enhancing N 2 fixation was advanced more than 50 years ago. Various programmes have sought to genetically improve a wide range of species, from pasture legumes such as red clover (Trifolium pratense) to the crop legumes like soybean (Glycine max) and common bean (Phaseolus vulgaris). In some the selection trait was yield, whilst in others it was high plant reliance on N 2 fixation (%Ndfa). A third strategy was to optimise legume nodulation through specific nodulation traits, e.g. mass, duration, promiscuous and selective nodulation. Plant genetic variation was sought from natural populations or created through mutagenesis. Although methods for assessing single plants and populations of plants for yield and %Ndfa varied over the years, it is now clear that measurements based on either 15 N or xylem solute analysis are the most reliable. Methodological issues as well as poor focus plagued many of the earlier programmes, since enhancing N 2 fixation essentially involves adapting legumes to fix more N when growing in N-poor soils. Programmes in which plant genotypes are inoculated with effective rhizobia and screened under conditions of low soil N maximise the symbiotic potential of the legume. (author)

  5. Ender’s Nail fixation in paediatric femoral shaft fractures.

    Directory of Open Access Journals (Sweden)

    Rajeev Dwivedi

    2013-12-01

    Flynn criteria 34 had excellent and 6 had satisfactory results. No poor results were seen. Conclusion: Ender’s nail fixation can be preferred method of treatment for femoral shaft fractures in age group 5 -15 years as the results are excellent and satisfactory. It is technically simple and can be done in a closed manner. It spares the vascularity and growth plate.

  6. Accuracy of a hexapod parallel robot kinematics based external fixator.

    Science.gov (United States)

    Faschingbauer, Maximilian; Heuer, Hinrich J D; Seide, Klaus; Wendlandt, Robert; Münch, Matthias; Jürgens, Christian; Kirchner, Rainer

    2015-12-01

    Different hexapod-based external fixators are increasingly used to treat bone deformities and fractures. Accuracy has not been measured sufficiently for all models. An infrared tracking system was applied to measure positioning maneuvers with a motorized Precision Hexapod® fixator, detecting three-dimensional positions of reflective balls mounted in an L-arrangement on the fixator, simulating bone directions. By omitting one dimension of the coordinates, projections were simulated as if measured on standard radiographs. Accuracy was calculated as the absolute difference between targeted and measured positioning values. In 149 positioning maneuvers, the median values for positioning accuracy of translations and rotations (torsions/angulations) were below 0.3 mm and 0.2° with quartiles ranging from -0.5 mm to 0.5 mm and -1.0° to 0.9°, respectively. The experimental setup was found to be precise and reliable. It can be applied to compare different hexapod-based fixators. Accuracy of the investigated hexapod system was high. Copyright © 2014 John Wiley & Sons, Ltd.

  7. Management and quantification of nitrogen fixation in Leucaena leucocephala

    International Nuclear Information System (INIS)

    Safo, E.Y.

    1998-01-01

    The effects of pruning and age on N 2 fixation were studied using Leucaena leucocephala isoline K28, with Cassia siamea as the non-N 2 -fixing reference species, at a site of degraded soil fertility typical of much of the farming land in Ghana. The 15 N-dilution method was used to estimate N2 fixation. Cassia siamea consistently produced higher total biomass and total N yields than did L. leucocephala. The mean value for the fraction of N derived from fixation (%Ndfa) was higher for pruned L. leucocephala (36%) than for unpruned trees (18%). There was some underestimation of N 2 fixation as a result of using C. siamea as the reference, and because root N-contents were not determined. Strong, significant linear correlations were observed between foliar and whole-tree (weighted average) percent 15 N atom excess in unpruned L. leucocephala and C. siamea, suggesting that foliar 15 N enrichment can be used to accurately estimate %Ndfa. The results demonstrated that the 15 N-enrichment methodology can provide meaningful estimates of %Ndfa and total N 2 fixed for mixed tree plantations under field conditions, when adequate spacing is provided. (author)

  8. Two isotopic methods for estimation of soybean nitrogen fixation

    International Nuclear Information System (INIS)

    Domenach, A.-M.; Chalamet, Alain; Pachiaudi, Christiane

    1979-01-01

    Measurements of rate of nitrogen symbiotic fixation by Soybean were determined by two different methods: variations in the natural abundance of 15 N in plants; use of 'A' value determined from labelled nitrogen applications to the soil. The results from both methods were in good agreement. Rates of fixed nitrogen were similar when using non nodulated Soybean or Ray-Grass as reference [fr

  9. Role of symbiotic nitrogen fixation in the improvement of legume ...

    African Journals Online (AJOL)

    Role of symbiotic nitrogen fixation in the improvement of legume productivity under stressed environments. R Serraj, J Adu-Gyamfi. Abstract. No Abstract. Full Text: EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/wajae.v6i1.45613.

  10. Capsule-Fixated Intraocular Lens Implantation in Small Pupil Cases.

    Science.gov (United States)

    Schojai, Merita; Schultz, Tim; Burkhard Dick, H

    2017-08-01

    To describe a new technique for implantation of capsule-fixated intraocular lenses (IOLs) (FEMTIS; Oculentis, Berlin, Germany) in patients with small pupils. In 4 eyes with small pupils, an anterior capsule-fixated IOL was implanted into the capsular bag after femtosecond laser treatment. The two large and two small flaps of the IOL were elevated to the front of the iris and the anterior capsule. Finally, the iris was flipped over the flaps to ensure a fixation of the capsule inside of the capsulotomy. In all cases, the implantation of anterior capsule-fixated IOLs was possible. No complications occurred during surgery or within the first months after surgery. With the described technique, capsulefixated IOLs can be implanted in eyes with small pupil easily and safely. This type of IOL has great potential to improve the refractive outcome by better prediction of the postoperative IOL position and eliminating IOL rotation after cataract surgery. [J Refract Surg. 2017;33(8):568-570.]. Copyright 2017, SLACK Incorporated.

  11. Operative fixation of chest wall fractures: an underused procedure?

    Science.gov (United States)

    Richardson, J David; Franklin, Glen A; Heffley, Susan; Seligson, David

    2007-06-01

    Chest wall fractures, including injuries to the ribs and sternum, usually heal spontaneously without specific treatment. However, a small subset of patients have fractures that produce overlying bone fragments that may produce severe pain, respiratory compromise, and, if untreated mechanically, result in nonunion. We performed open reduction and internal fixation on seven patients with multiple rib fractures-five in the initial hospitalization and two delayed--as well as 35 sternal fractures (19 immediate fixation and 16 delayed). Operative fixation was accomplished using titanium plates and screws in both groups of patients. All patients with rib fractures did well; there were no major complications or infections, and no plates required removal. Clinical results were excellent. There was one death in the sternal fracture group in a patient who was ventilator-dependent preoperatively and extubated himself in the early postoperative period. Otherwise, the results were excellent, with no complications occurring in this group. Three patients had their plates removed after boney union was achieved. No evidence of infection or nonunion occurred. The excellent results achieved in the subset of patients with severe chest wall deformities treated initially at our institution and those referred from outside suggest that operative fixation is a useful modality that is likely underused.

  12. Cyanobacteria Occurrence and Nitrogen Fixation Rates in the ...

    African Journals Online (AJOL)

    The occurrence and biological nitrogen fixation rates of epiphytic and benthic diazotrophs were studied in seagrass meadows at sites with seaweed farms and at a control site without seaweed farms from two locations, Chwaka Bay and Jambiani, along the east coast of. Zanzibar. Ten species of cyanobacteria were ...

  13. Biomechanical analysis of titanium fixation plates and screws in ...

    African Journals Online (AJOL)

    2015-08-10

    Aug 10, 2015 ... values on fixative appliances were predicted by means of. 3D FEA. The highest ... such as poor resistance to torsional forces, poor rigidity, and poor stability in ... the adequacy of mathematical models to relate mechanical factors such as ... the risk of bacterial contamination, scarring, postoperative edema ...

  14. Nitrogen fixation and nitrogenase activity of Azotobacter chroococcum

    NARCIS (Netherlands)

    Brotonegoro, S.

    1974-01-01

    The purpose of the present investigation was to study the effect of some chemical, physical and biological factors on growth, efficiency of nitrogen fixation and nitrogenase activity of Azotobacter chroococcum.

    From biochemical studies with cell-free

  15. Resorbable screws for fixation of autologous bone grafts

    NARCIS (Netherlands)

    Raghoebar, GM; Liem, RSB; Bos, RRM; van der Wal, JE; Vissink, A

    The aim of this study was to evaluate the suitability of resorbable screws made of poly (D,L-lactide) acid (PDLLA) for fixation of autologous bone grafts related to graft regeneration and osseointegration of dental implants. In eight edentulous patients suffering from insufficient retention of their

  16. Serious complication 1?year after sacrospinous ligament fixation

    OpenAIRE

    Faber, Violet J.; van der Vaart, Huub C.; Heggelman, Ben G. F.; Schraffordt Koops, Steven E.

    2008-01-01

    Myositis of the gluteal region caused by group A streptococci 1 year after a sacrospinous ligament fixation was recognised as a serious complication of this procedure. Most likely, the infection was spread to the gluteal region through a port d’entree caused by vaginal atrophy, via the non-resorbable sutures. The patient was treated successfully with antibiotics intravenous and local estrogens.

  17. Button fixation technique for Achilles tendon reinsertion: a biomechanical study.

    Science.gov (United States)

    Awogni, David; Chauvette, Guillaume; Lemieux, Marie-Line; Balg, Frédéric; Langelier, Ève; Allard, Jean-Pascal

    2014-01-01

    Chronic insertional tendinopathy of the Achilles tendon is a frequent and disabling pathologic entity. Operative treatment is indicated for patients for whom nonoperative management has failed. The treatment can consist of the complete detachment of the tendon insertion and extensive debridement. We biomechanically tested a new operative technique that uses buttons for fixation of the Achilles tendon insertion on the posterior calcaneal tuberosity and compared it with 2 standard bone anchor techniques. A total of 40 fresh-frozen cadaver specimens were used to compare 3 fixation techniques for reinserting the Achilles tendon: single row anchors, double row anchors, and buttons. The ultimate loads and failure mechanisms were recorded. The button assembly (median load 764 N, range 713 to 888) yielded a median fixation strength equal to 202% (range 137% to 251%) of that obtained with the double row anchors (median load 412 N, range 301 to 571) and 255% (range 213% to 317%) of that obtained with the single row anchors (median load 338 N, range 241 to 433N). The most common failure mechanisms were suture breakage with the buttons (55%) and pull out of the implant with the double row (70%) and single row (85%) anchors. The results of the present biomechanical cadaver study have shown that Achilles tendon reinsertion fixation using the button technique provides superior pull out strength than the bone anchors tested. Copyright © 2014 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  18. Estimates of biological nitrogen fixation by Pterocarpus lucens in a ...

    African Journals Online (AJOL)

    Nitrogen (N2) fixation by Pterocarpus lucens in a natural semi arid ecosystem, in Ferlo, Senegal was estimated using 15N natural abundance (15N) procedure. Other non-fixing trees accompanying P. lucens in the same area were also investigated as control. Results showed an important variation of 15N in leaves between ...

  19. Nodulation and nitrogen fixation in common bean (Phaseolus vulgaris)

    African Journals Online (AJOL)

    Mamadou Gueye

    Nodulation and nitrogen fixation of field grown common bean (Phaseolus vulgaris) as influenced by fungicide seed treatment. Ndeye Fatou Diaw GUENE, Adama DIOUF and Mamadou GUEYE*. MIRCEN/ Laboratoire commun de microbiologie IRD-ISRA-UCAD, BP 1386, DAKAR, Senegal. Accepted 23 June 2003.

  20. Fixating the pelvis in the horizontal plane affects gait characteristics

    NARCIS (Netherlands)

    Veneman, J.F.; Menger, Jasper; van Asseldonk, Edwin H.F.; van der Helm, F.C.T.; van der Kooij, Herman

    2008-01-01

    In assistive devices for neuro-rehabilitation, natural human motions are partly restricted by the device. This may affect the normality of walking during training. This research determines effects on gait of fixating the pelvis translations in the horizontal plane during treadmill walking. Direct

  1. variability in olecranon ao fracture fixation: a radiological study

    African Journals Online (AJOL)

    ABSTRACT. Background: Tension Band Wire(TBW) fixation of olecranon fracture is a commonly used technique by ... There are many classification systems of this injury of which the Mayo is ... backing out by as much as three times in comparison with those ..... “K” wire. A blinded randomized control outcome based clinical.

  2. Differences in fixations between grasping and viewing objects

    NARCIS (Netherlands)

    Brouwer, A.M.; Franz, V.H.; Gegenfurtner, K.R.

    2009-01-01

    Where exactly do people look when they grasp an object? An object is usually contacted at two locations, whereas the gaze can only be at one location at the time. We investigated participants' fixation locations when they grasp objects with the contact positions of both index finger and thumb being

  3. Ad gist : Ad communication in a single eye fixation

    NARCIS (Netherlands)

    Pieters, R.; Wedel, M.

    2012-01-01

    Most ads in practice receive no more than a single eye fixation. This study investigates the limits of what ads can communicate under such adverse exposure conditions. We find that consumers already know at maximum levels of accuracy and with high degree of certainty whether something is an ad or is

  4. Adaptation and fixation in entrepreneurial approaches of a dental laboratory

    Directory of Open Access Journals (Sweden)

    Cornelia M. Ferreira

    2014-08-01

    Research purpose: The study described how the dental laboratory adapted its entrepreneurial approaches over time in response to critical changes that occurred and how aspects in the managerial approach became fixated and proved to be essential to success. Motivation for the study: The study provided insight into how the dental laboratory transformed into a stable and prosperous laboratory by the integration of strategic, economic, cultural and social capital through a process of business decision making. Research design, approach and method: A cohort survey research design, based upon the compilation of longitudinal data over three selected time periods, was employed. The design of the measuring instruments and the interpretation of research results were derived from an adapted entrepreneurial-in-network theoretical framework. A triangulation data compilation approach was followed. Main findings: The results revealed that cultural capital in the dental laboratory became fixated on three value principles, whilst the other critical capitals prescribed exist in sufficient volumes and improve to adapt to changing circumstances in the dental market. Practical/managerial implications: Fixated cultural values acted as a ‘parent’-actor in order to guide the righteousness of behaviour, whereas adaptation required sufficient critical capitals and the proper integration thereof. Contribution/value-added: By adopting the entrepreneurship-in-network approach, the researchers incorporated the dynamic and interactive processes of entrepreneurship. Future studies may employ the same design and use multi-varied analyses to show how a business adapt or fixate its approaches in response to crises or changes in the business environment.

  5. Improved coating and fixation methods for scanning electron microscope autoradiography

    International Nuclear Information System (INIS)

    Weiss, R.L.

    1984-01-01

    A simple apparatus for emulsion coating is described. The apparatus is inexpensive and easily assembled in a standard glass shop. Emulsion coating for scanning electron microscope autoradiography with this apparatus consistently yields uniform layers. When used in conjunction with newly described fixation methods, this new approach produces reliable autoradiographs of undamaged specimens

  6. N-2 fixation by non-heterocystous cyanobacteria

    NARCIS (Netherlands)

    Bergman, B.; Gallon, J.R.; Rai, A.N.; Stal, L.J.

    1997-01-01

    Many, though not all, non-heterocystous cyanobacteria can fix N-2. However, very few strains can fix N-2 aerobically. Nevertheless, these organisms may make a substantial contribution to the global nitrogen cycle. In this general review, N-2 fixation by laboratory cultures and natural populations of

  7. Functional Outcome of Internal Fixation of Radial and Ulna Fracture

    Directory of Open Access Journals (Sweden)

    mehrdad Mansouri

    2006-02-01

    Conclusion: Anatomic reduction and internal fixation is the standard method for treatment of fractures by displacing radios and ulna in adults. According to results, it seems more intension to motions specially pronation and muscle strengthening foream after surgery will have affect on improving patients’ function specially pronation and Grip strength.

  8. Single-suture scleral fixation of subluxated foldable intraocular lenses.

    Science.gov (United States)

    Yarangumeli, Alper; Alp, Mehmet Numan; Kural, Gulcan

    2012-01-01

    To evaluate the results of single-suture scleral fixation of subluxated foldable intraocular lenses (IOL) in eyes with sufficient residual capsular support. The results of IOL repositioning by single-suture scleral fixation in 6 eyes of 6 patients with IOL subluxation were included. All subluxated IOLs were single-piece hydrophilic acrylic. Subluxation resulted from posterior capsule tears in 3 eyes, zonular dialyses in 2 eyes, and zonular dialysis with a capsulorhexis tear in 1 eye. A similar technique was used in all eyes in which one haptic was externalized through a superior clear corneal incision and tied with a Pair-PAK 10-0 polypropylene suture, and was finally retracted and fixated behind the iris close to the ciliary sulcus at the 12:00 meridian. All patients were followed up for at least 6 months. Best-corrected visual acuities ranged between finger counting and 20/70 (mean logMAR 1.02±0.64) preoperatively, and between 20/100 and 20/20 (mean logMAR 0.22±0.26) at the final postoperative visit. All IOLs remained centered and no significant postoperative complications were encountered except for an IOL tilt which resulted in a considerable oblique astigmatism in one eye. Subluxated foldable IOLs may safely be repositioned and secured with a single scleral fixation suture in selected cases with adequate amount of capsular remnants.

  9. Intraocular lens iris fixation. Clinical and macular OCT outcomes

    Science.gov (United States)

    2012-01-01

    Background To assess the efficacy, clinical outcomes, visual acuity (VA), incidence of adverse effects, and complications of peripheral iris fixation of 3-piece acrylic IOLs in eyes lacking capsular support. Thirteen patients who underwent implantation and peripheral iris fixation of a 3-piece foldable acrylic PC IOL for aphakia in the absence of capsular support were followed after surgery. Clinical outcomes and macular SD-OCT (Cirrus OCT; Carl Zeiss Meditec, Germany) were analyzed. Findings The final CDVA was 20/40 or better in 8 eyes (62%), 20/60 or better in 12 eyes (92%), and one case of 20/80 due to corneal astigmatism and mild persistent edema. No intraoperative complications were reported. There were seven cases of medically controlled ocular hypertension after surgery due to the presence of viscoelastic in the AC. There were no cases of cystoid macular edema, chronic iridocyclitis, IOL subluxation, pigment dispersion, or glaucoma. Macular edema did not develop in any case by means of SD-OCT. Conclusions We think that this technique for iris suture fixation provides safe and effective results. Patients had substantial improvements in UDVA and CDVA. This surgical strategy may be individualized however; age, cornea status, angle structures, iris anatomy, and glaucoma are important considerations in selecting candidates for an appropriate IOL fixation method. PMID:23050659

  10. Intermediate results of sutureless intrascleral posterior chamber intraocular lens fixation.

    Science.gov (United States)

    Scharioth, Gabor B; Prasad, Som; Georgalas, Ilias; Tataru, Calin; Pavlidis, Mitrofanis

    2010-02-01

    To report the intermediate multicenter results of a technique of sutureless intrascleral fixation of a standard 3-piece posterior chamber intraocular lens (PC IOL) in the ciliary sulcus. Four European ophthalmology centers. A technique for sutureless intrascleral fixation of the haptics of a standard 3-piece PC IOL was retrospectively evaluated. The technique uses standardized maneuvers to fixate the PC IOL without need for special haptic architecture or preparation or haptic suturing. All patients having IOL implantation by the technique were evaluated for preoperative status (visual acuity, refractive error, preexisting ocular conditions, optical biometry), postoperative status, complications, and need for further surgery. The study evaluated 63 consecutive patients from 4 institutions (4 surgeons). The median follow-up was 7 months. Two dislocated PC IOLs (3.6%) were decentered; the other 61 IOLs (96.8%) were stable and well centered. There were no cases of recurrent dislocation, endophthalmitis, retinal detachment, or glaucoma. Fixation of PC IOL haptics in a limbus-parallel scleral tunnel provided exact centration and axial stability of the IOL and prevented distortion and subluxation in most cases. Copyright 2010 ASCRS and ESCRS. All rights reserved.

  11. Intraocular lens iris fixation. Clinical and macular OCT outcomes

    Directory of Open Access Journals (Sweden)

    Garcia-Rojas Leonardo

    2012-10-01

    Full Text Available Abstract Background To assess the efficacy, clinical outcomes, visual acuity (VA, incidence of adverse effects, and complications of peripheral iris fixation of 3-piece acrylic IOLs in eyes lacking capsular support. Thirteen patients who underwent implantation and peripheral iris fixation of a 3-piece foldable acrylic PC IOL for aphakia in the absence of capsular support were followed after surgery. Clinical outcomes and macular SD-OCT (Cirrus OCT; Carl Zeiss Meditec, Germany were analyzed. Findings The final CDVA was 20/40 or better in 8 eyes (62%, 20/60 or better in 12 eyes (92%, and one case of 20/80 due to corneal astigmatism and mild persistent edema. No intraoperative complications were reported. There were seven cases of medically controlled ocular hypertension after surgery due to the presence of viscoelastic in the AC. There were no cases of cystoid macular edema, chronic iridocyclitis, IOL subluxation, pigment dispersion, or glaucoma. Macular edema did not develop in any case by means of SD-OCT. Conclusions We think that this technique for iris suture fixation provides safe and effective results. Patients had substantial improvements in UDVA and CDVA. This surgical strategy may be individualized however; age, cornea status, angle structures, iris anatomy, and glaucoma are important considerations in selecting candidates for an appropriate IOL fixation method.

  12. Two isotopic methods for estimation of soybean nitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)

    Domenach, A M; Chalamet, A; Pachiaudi, C [Lyon-1 Univ., 69 - Villeurbanne (France)

    1979-07-16

    Measurements of rate of nitrogen symbiotic fixation by Soybean were determined by two different methods: variations in the natural abundance of /sup 15/N in plants; use of 'A' value determined from labelled nitrogen applications to the soil. The results from both methods were in good agreement. Rates of fixed nitrogen were similar when using non nodulated Soybean or Ray-Grass as reference.

  13. The clinical outcome of lateral mass fixation after decompressive ...

    African Journals Online (AJOL)

    Ahmed Yehya

    2014-10-11

    Oct 11, 2014 ... Abstract Lateral mass cervical fixation is the technique of choice for posterior cervical stabiliza- tion of the lower ... In group I, neck pain improved in 68.8% and brachialgia improved in 83.3% .... a p value for Student t-test.

  14. Carbon Dioxide for pH Control

    Energy Technology Data Exchange (ETDEWEB)

    Wagonner, R.C.

    2001-08-16

    Cardox, the major supplier of carbon dioxide, has developed a diffuser to introduce carbon dioxide into a water volume as small bubbles to minimize reagent loss to the atmosphere. This unit is integral to several configurations suggested for treatment to control alkalinity in water streams.

  15. Carbon dioxide sequestration by mineral carbonation

    NARCIS (Netherlands)

    Huijgen, W.J.J.

    2007-01-01

    The increasing atmospheric carbon dioxide (CO2) concentration, mainly caused by fossil fuel combustion, has lead to concerns about global warming. A possible technology that can contribute to the reduction of carbon dioxide emissions is CO2 sequestration by mineral carbonation. The basic concept

  16. Trading coalbed methane for carbon dioxide

    International Nuclear Information System (INIS)

    Greenberger, L.S.

    1991-01-01

    This article discusses a proposal for reducing methane emissions in coal mining activities and at the same time reducing the burden on utilities to cut carbon dioxide emissions. Emission credits would be issued to mines that recover the methane for use. These credits could then be bought by utilities and exchanged for the right to emit carbon dioxide

  17. Pressure pumping of carbon dioxide from soil

    Science.gov (United States)

    E. S. Takle; J. R. Brandle; R. A. Schmidt; R. Garcia; I. V. Litvina; G. Doyle; X. Zhou; Q. Hou; C. W. Rice; W. J. Massman

    2000-01-01

    Recent interest in atmospheric increases in carbon dioxide have heightened the need for improved accuracy in measurements of fluxes of carbon dioxide from soils. Diffusional movement has long been considered the dominant process by which trace gases move from the subsurface source to the surface, although there has been some indication that atmospheric pressure...

  18. Process for the preparation of uranium dioxide

    International Nuclear Information System (INIS)

    Watt, G.W.; Baugh, D.W. Jr.

    1981-01-01

    A method for the preparation of actinide dioxides using actinide nitrate hexahydrates as starting materials is described. The actinide nitrate hexahydrate is reacted with sodium dithionite, and the product is heated in the absence of oxygen to obtain the dioxide. Preferably, the actinide is uranium, plutonium or neptunium. (LL)

  19. Thermoexpanded graphite modification by titanium dioxide

    International Nuclear Information System (INIS)

    Semko, L.S.; Gorbik, P.P.; Chujko, O.O.; Kruchek, Ya.Yi.; Dzyubenko, L.S.; Orans'ka, O.Yi.

    2006-01-01

    A method of the synthesis of thermoexpanded graphite (TEG) powders coated by titanium dioxide is developed. The conversion of n-buthylorthotitanate into TiO 2 on the TEG surface is investigated. The optimal parameters of the synthesis and the structure of titanium dioxide clusters on the TEG surface are determined

  20. Elevated CO2 concentration around alfalfa nodules increases N2 fixation

    OpenAIRE

    Fischinger, Stephanie A.; Hristozkova, Marieta; Mainassara, Zaman-Allah; Schulze, Joachim

    2009-01-01

    Nodule CO2 fixation via PEPC provides malate for bacteroids and oxaloacetate for N assimilation. The process is therefore of central importance for efficient nitrogen fixation. Nodule CO2 fixation is known to depend on external CO2 concentration. The hypothesis of the present paper was that nitrogen fixation in alfalfa plants is enhanced when the nodules are exposed to elevated CO2 concentrations. Therefore nodulated plants of alfalfa were grown in a hydroponic system that allowed separate ae...

  1. Porcine intestinal mast cells. Evaluation of different fixatives for histochemical staining techniques considering tissue shrinkage

    Directory of Open Access Journals (Sweden)

    J. Rieger

    2013-07-01

    Full Text Available Staining of mast cells (MCs, including porcine ones, is critically dependent upon the fixation and staining technique. In the pig, mucosal and submucosal MCs do not stain or stain only faintly after formalin fixation. Some fixation methods are particularly recommended for MC staining, for example the fixation with Carnoy or lead salts. Zinc salt fixation (ZSF has been reported to work excellently for the preservation of fixation-sensitive antigens. The aim of this study was to establish a reliable histological method for counting of MCs in the porcine intestinum. For this purpose, different tissue fixation and staining methods that also allow potential subsequent immunohistochemical investigations were evaluated in the porcine mucosa, as well as submucosa of small and large intestine. Tissues were fixed in Carnoy, lead acetate, lead nitrate, Zamboni and ZSF and stained subsequently with either polychromatic methylene blue, alcian blue or toluidine blue. For the first time our study reveals that ZSF, a heavy metal fixative, preserves metachromatic staining of porcine MCs. Zamboni fixation was not suitable for histochemical visualization of MCs in the pig intestine. All other tested fixatives were suitable. Alcian blue and toluidine blue co-stained intestinal goblet cells which made a prima facie identification of MCs difficult. The polychromatic methylene blue proved to be the optimal staining. In order to compare MC counting results of the different fixation methods, tissue shrinkage was taken into account. As even the same fixation caused shrinkage-differences between tissue from small and large intestine, different factors for each single fixation and intestinal localization had to be calculated. Tissue shrinkage varied between 19% and 57%, the highest tissue shrinkage was found after fixation with ZSF in the large intestine, the lowest one in the small intestine after lead acetate fixation. Our study emphasizes that MC counting results from

  2. Carbon dioxide production in animal houses

    DEFF Research Database (Denmark)

    Pedersen, Søren; Blanes-Vidal, Victoria; Joergensen, H.

    2008-01-01

    cellars are emptied regularly in a four weeks interval. Due to a high and variable carbon dioxide production in deep straw litter houses and houses with indoor storage of manure longer than four weeks, we do not recommend to calculate the ventilation flow based on the carbon dioxide concentration......This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from...... animal houses). The investigations include measurements in respiration chambers and in animal houses, mainly for growing pigs and broilers. Over the last decade a fixed carbon dioxide production of 185 litres per hour per heat production unit, hpu (i.e. 1000 W of the total animal heat production at 20o...

  3. Adjacent-segment disease after thoracic pedicle screw fixation.

    Science.gov (United States)

    Agarwal, Nitin; Heary, Robert F; Agarwal, Prateek

    2018-03-01

    OBJECTIVE Pedicle screw fixation is a technique widely used to treat conditions ranging from spine deformity to fracture stabilization. Pedicle screws have been used traditionally in the lumbar spine; however, they are now being used with increasing frequency in the thoracic spine as a more favorable alternative to hooks, wires, or cables. Although safety concerns, such as the incidence of adjacent-segment disease (ASD) after cervical and lumbar fusions, have been reported, such issues in the thoracic spine have yet to be addressed thoroughly. Here, the authors review the literature on ASD after thoracic pedicle screw fixation and report their own experience specifically involving the use of pedicle screws in the thoracic spine. METHODS Select references from online databases, such as PubMed (provided by the US National Library of Medicine at the National Institutes of Health), were used to survey the literature concerning ASD after thoracic pedicle screw fixation. To include the authors' experience at Rutgers New Jersey Medical School, a retrospective review of a prospectively maintained database was performed to determine the incidence of complications over a 13-year period in 123 consecutive adult patients who underwent thoracic pedicle screw fixation. Children, pregnant or lactating women, and prisoners were excluded from the review. By comparing preoperative and postoperative radiographic images, the occurrence of thoracic ASD and disease within the surgical construct was determined. RESULTS Definitive radiographic fusion was detected in 115 (93.5%) patients. Seven incidences of instrumentation failure and 8 lucencies surrounding the screws were observed. One patient was observed to have ASD of the thoracic spine. The mean follow-up duration was 50 months. CONCLUSIONS This long-term radiographic evaluation revealed the use of pedicle screws for thoracic fixation to be an effective stabilization modality. In particular, ASD seems to be less of a problem in the

  4. Fixation of Soil Using PEC and Separation of Fixed Soil

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Yong Suk; Yang, Hee-Man; Lee, Kune Woo; Seo, Bum-Kyoung; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2014-10-15

    Radioactive cesium (Cs-137) is the most apprehensive element due to its long half-lives, high solubility in water, and strong radiation emission in the form of gamma rays. Because the radioactivity is localized within topsoil, soil surface on topsoil should be fixed to prevent the spreading of the contaminated soils by wind and water erosion. Many methods have been developing for soil fixation to remove radioactive contaminants in soil and prevent to diffuse radioactive materials. Various materials have been used as fixatives such as clays, molecular sieves, polymer, and petroleum based products. One of the methods is a soil fixation or solidification using polyelectrolyte. Polyelectrolytes have many ionic groups and form the polyelectrolyte complex (PEC) due to electrostatic interaction of anion and cation in an aqueous solution. polyelectrolyte complex can fix soil particles by flocculation and formation of crust between soil. The method can prevent a spread of radioactive material by floating on a soil surface. The decontamination efficiency of the surface soils reached about 90%, and dust release was effectively suppressed during the removal of surface soils. However it has a problem that the removed soil must separate soil and polymer to treat as the waste. In this study, the fixation of soil by polyelectrolyte complex to suppress the spread of contaminant and the separation method of soil and polymer was investigated. The properties of polyelectrolyte complex solution and the stability of fixed soil by polyelectrolyte complex were investigated. The concentration of salt in the polyelectrolyte complex solution is a very important parameter for the soil fixation.

  5. Surface fixation of dried blood by glutaraldehyde and peracetic acid.

    Science.gov (United States)

    Kampf, G; Bloss, R; Martiny, H

    2004-06-01

    The difficulties of successful prion inactivation by chemical agents has led to changes in recommendations regarding the reprocessing of instruments including flexible endoscopes. One of the changes is the preference for peracetic acid instead of glutaraldehyde in order to avoid fixation of organic material, but the surface fixation by various active agents has not been fully investigated. We used a standardized amount of dried blood soil on metal carriers (on average 22 mg). One part of the carriers was exposed to different disinfectants (four based on peracetic acid, three based on glutaraldehyde, two based on quaternary ammonium compounds (QAC), one based on QAC and amines, one based on phenols and one cleaning agent) and air dried. The difference compared with the non-exposed soiled carrier was taken as the measure of blood removal by exposure to the disinfectants. In addition the other part of the carriers was exposed to a cleaning agent and air dried. The cleaning agent itself was capable of removing more than 99% of the dried blood and served as a control for non-fixation. The rate of fixation of dried blood was calculated as the ratio of the weight of residual soil on 'soiled, disinfected and cleaned' carriers and on 'soiled and disinfected' carriers. All experiments were repeated eight times. Blood removal varied between 90.3% +/- 1.5% (phenol-based disinfectant) and peracetic acid. No other preparations showed a potential for blood fixation (peracetic acid, and support the evidence that effective cleaning should precede the chemical disinfection. Copyright 2004 The Hospital Infection Society

  6. Surgical treatment of neglected clubfoot using external fixator

    Directory of Open Access Journals (Sweden)

    Rodrigo Mota Pacheco Fernandes

    Full Text Available ABSTRACT The definition of neglected clubfoot (NC includes a variable range of complex deformities of the foot that are refractory to conventional treatments or are treated inappropriately. Several etiologies may be related to this. The Ilizarov method has become established as a tool for treating these deformities. It minimizes soft-tissue damage through gradual correction of the deformity, with a high success rate in relation to achieving a plantigrade foot, with low incidence of recurrence. The indications for treatment include severe rigid deformities (Dimeglio III and IV, or adverse skin conditions. Careful clinical and radiological examination is fundamental for proper planning and installation of the external fixator. The techniques used include selection of external fixation assemblies, which can be closed when there is a connection between the leg, hindfoot and forefoot. This closed assembly may or may not be constricted, according to whether hinges are provided or whether use of the natural anatomical hinges during correction of the deformity is envisaged. An open assembly makes it possible to add flexibility to the foot through histogenesis, while allowing closed corrections of greater precision later on. Hexapod fixators are an innovation with high potential for accuracy in correcting deformities. Procedures associated with external fixation include soft-tissue release and bone procedures. These procedures enable corrections that are more anatomical, for different degrees of severity and stiffness of deformity. It can be concluded from analyzing this case series that treatment of neglected clubfoot using an external fixator has a high rate of good and excellent results, with low frequency of complications.

  7. Flanged Intrascleral Intraocular Lens Fixation with Double-Needle Technique.

    Science.gov (United States)

    Yamane, Shin; Sato, Shimpei; Maruyama-Inoue, Maiko; Kadonosono, Kazuaki

    2017-08-01

    To report the clinical outcomes of a new technique for transconjunctival intrascleral fixation of an intraocular lens (IOL). Prospective, noncomparative, interventional case series. One hundred eyes of 97 consecutive patients with aphakia, dislocated IOL, or subluxated crystalline lens who underwent posterior chamber sutureless implantation of an IOL were studied. Two angled incisions parallel to the limbus were made by 30-gauge thin-wall needles. Haptics of an IOL were externalized with the needles and cauterized to make a flange of the haptics. The flange of the haptics were pushed back and fixed into the scleral tunnels. Best-corrected visual acuity (VA), corneal endothelial cell density, IOL tilt, and complications were determined. The IOLs were fixed with exact centration and axial stability. The mean preoperative best-corrected VA was 0.25 logarithm of the minimum angle of resolution (logMAR) units; after surgery, it improved significantly to 0.11 logMAR, 0.09 logMAR, 0.12 logMAR, and 0.04 logMAR at 6, 12, 24, and 36 months, respectively (P IOL tilt was 3.4°±2.5°. The postoperative complications included iris capture by the IOL in 8 eyes (8%), vitreous hemorrhage in 5 eyes (5%), and cystoid macular edema in 1 eye (1%). There were no incidents of postoperative retinal detachment, endophthalmitis, or IOL dislocation. We have developed a new technique for intrascleral IOL fixation. The flanged IOL fixation technique is a simple and minimally invasive method for achieving good IOL fixation with firm haptic fixation. Copyright © 2017 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

  8. Ethanol-Glycerin Fixation with Thymol Conservation: A Potential Alternative to Formaldehyde and Phenol Embalming

    Science.gov (United States)

    Hammer, Niels; Loffler, Sabine; Feja, Christine; Sandrock, Mara; Schmidt, Wolfgang; Bechmann, Ingo; Steinke, Hanno

    2012-01-01

    Anatomical fixation and conservation are required to prevent specimens from undergoing autolysis and decomposition. While fixation is the primary arrest of the structures responsible for autolysis and decomposition, conservation preserves the state of fixation. Although commonly used, formaldehyde has been classified as carcinogenic to humans. For…

  9. The effect of hubs and shortcuts on fixation time in evolutionary graphs

    Science.gov (United States)

    Askari, Marziyeh; Moradi Miraghaei, Zeinab; Aghababaei Samani, Keivan

    2017-07-01

    How can a new species (like a gene, an idea, or a strategy) take over the whole of a population? This process, which is called fixation, is considerably affected by the structure of the population. There are two key quantities to quantify the fixation process, namely fixation probability and fixation time. Fixation probability has been vastly studied in recent years, but fixation time has not been completely explored, yet. This is because the discovery of a relationship between fixation time and network structure is quite challenging. In this paper we investigate this relationship for a number of well-known complex networks. We show that the existence of a few high-degree nodes (hubs) in the network results in a longer fixation time, while the existence of a few short-cuts decreases the fixation time. Furthermore we investigate the effect of network parameters, such as connection probability, on fixation time. We show that by increasing the density of edges, fixation time decreases for all types of studied networks. Finally, we survey the effect of rewiring probability in a Watts-Strogatz network on fixation time.

  10. The role of minimally invasive plate osteosynthesis in rib fixation : A review

    NARCIS (Netherlands)

    Bemelman, Michael; Van Baal, Mark; Yuan, Jian Zhang; Leenen, Luke

    2016-01-01

    More than a century ago, the first scientific report was published about fracture fixation with plates. During the 1950's, open reduction and plate fixation for fractures were standardized by the founders of Arbeitsgemeinschaft für osteosynthesefragen/Association for the Study of Internal Fixation.

  11. The interactive effects of temperature and moisture on nitrogen fixation in two temperate-arctic mosses

    DEFF Research Database (Denmark)

    Rousk, Kathrin; Pedersen, Pia Agerlund; Dyrnum, Kristine

    2017-01-01

    fixation in mosses under controlled conditions have rarely been investigated separately, rendering the interactive effects of the two climatic factors on N2 fixation unknown. Here, we tested the interactive effects of temperature and moisture on N2 fixation in the two most dominant moss species...

  12. Comparison of /sup 15/N-aided methods for determining symbiotic dinitrogen fixation

    Energy Technology Data Exchange (ETDEWEB)

    Rennie, R J [International Atomic Energy Agency, Vienna (Austria). Joint FAO/IAEA Div. of Atomic Energy in Food and Agriculture

    1979-01-01

    Three methods of calculating the amount of symbiotic dinitrogen fixation in navy beans (Phaseolus vulgaris cv. Sanilac) were compared in a greenhouse experiment. /sup 15/N-isotope dilution procedures yielded the most logical estimation of dinitrogen fixation. The classical difference method was not in agreement. Potential errors of the 'A'-value procedure to calculate dinitrogen fixation are discussed.

  13. Four quadrant parallel peripheral screw fixation for displaced femoral neck fractures in elderly patients

    Directory of Open Access Journals (Sweden)

    Bhava RJ Satish

    2013-01-01

    Conclusion: Closed reduction and cannulated cancellous screw fixation gives satisfactory functional results in large group of elderly patients. The four quadrant parallel peripheral (FQPP screw fixation technique gives good stability, allows controlled collapse, avoids fixation failure and achieves predictable bone healing in displaced femoral neck fracture in patients ≥50 years of age.

  14. Fixation of Radionuclides in Titanium Dioxide and Titanates via co-Precipitation; Fixation de Radioelements dans le Bioxyde de Titane et dans les Titanates par Coprecipitation; 0424 0418 041a 0421 0410 0426 0418 042f 0420 0410 0414 0418 041e 0418 0417 041e 0422 041e 041f 041e 0412 0412 0414 0412 0423 041e 041a 0418 0421 0418 0422 0418 0422 0410 041d 0410 0418 1 0418 0422 0410 041d 0410 0422 0410 0425 041c 0415 0422 041e 0414 041e 041c 0421 041e 041e 0421 0410 0416 0414 0415 041d 0418 042f ; Fijacion de Radionuclidos en Dioxido de Titanio y Titanatos por Coprecipitacion

    Energy Technology Data Exchange (ETDEWEB)

    Levi, H. W. [Hahn-Meitner Institut fuer Kernforschung, Berlin-Wannsee, Federal Republic of Germany (Germany)

    1963-02-15

    Calcination and adsorption on clay minerals are the most frequently studied ways of radionuclide fixation. A third way - fixation via co-precipitation - has not attracted much interest up to now. The characteristic for all three methods is high-temperature treatment of a pre-product containing the radioactivity, but they differ in introducing the activity into this pre-product. The disadvantages of co-precipitation are the difficult separation of the highly active sludge from solution and its bad qualification for caesium removal. Its advantages are the suitability for head-end processes, the less restricted volume capacity compared with clay mineral adsorption, and the avoidance of evaporation operations. Therefore it seemed worth while to look more closely into the chemistry of proper co-precipitation systems. The first system chosen was TiO{sub 2} * aq because of the good fixation qualities of TiO{sub 2} and titanates. The co-precipitation properties of TiO{sub 2} * aq were studied under different experimental conditions. For some radionuclides the distribution coefficient was found to be as good as or better than that for other oxide hydrates. High concentration of the radionuclide ion or similar ions causes decreasing distribution coefficient. This could be avoided by simultaneously precipitating carbonates or oxalates which remove the bulk oi the ions. The influence of high aluminium content was studied as well. An investigation of the formation of anatas and rutil from pure TiO{sub 2} * aq precipitates and of titanates from TiO{sub 2} * aq + carbonate or oxalate precipitates during high-temperature treatment was started. (author) [French] La calcination et l'adsorption par les mineraux argileux sont les modes de fixation des radioelements les plus frequemment etudies. Une troisieme methode, la fixation par coprecipitation, n'a guere suscite d'interet jusqu'a present. Ces trois methodes ont un point commun: le traitement a haute temperature des matieres

  15. Mucin secretion induced by titanium dioxide nanoparticles.

    Directory of Open Access Journals (Sweden)

    Eric Y T Chen

    2011-01-01

    Full Text Available Nanoparticle (NP exposure has been closely associated with the exacerbation and pathophysiology of many respiratory diseases such as Chronic Obstructive Pulmonary Disease (COPD and asthma. Mucus hypersecretion and accumulation in the airway are major clinical manifestations commonly found in these diseases. Among a broad spectrum of NPs, titanium dioxide (TiO(2, one of the PM10 components, is widely utilized in the nanoindustry for manufacturing and processing of various commercial products. Although TiO(2 NPs have been shown to induce cellular nanotoxicity and emphysema-like symptoms, whether TiO(2 NPs can directly induce mucus secretion from airway cells is currently unknown. Herein, we showed that TiO(2 NPs (<75 nm can directly stimulate mucin secretion from human bronchial ChaGo-K1 epithelial cells via a Ca(2+ signaling mediated pathway. The amount of mucin secreted was quantified with enzyme-linked lectin assay (ELLA. The corresponding changes in cytosolic Ca(2+ concentration were monitored with Rhod-2, a fluorescent Ca(2+ dye. We found that TiO(2 NP-evoked mucin secretion was a function of increasing intracellular Ca(2+ concentration resulting from an extracellular Ca(2+ influx via membrane Ca(2+ channels and cytosolic ER Ca(2+ release. The calcium-induced calcium release (CICR mechanism played a major role in further amplifying the intracellular Ca(2+ signal and in sustaining a cytosolic Ca(2+ increase. This study provides a potential mechanistic link between airborne NPs and the pathoetiology of pulmonary diseases involving mucus hypersecretion.

  16. Regulation of methanol oxidation and carbon dioxide fixation in Xanthobacter strain 25a grown in continuous culture

    NARCIS (Netherlands)

    Croes, L.M.; Meijer, Wilhelmus; Dijkhuizen, L.

    The regulation of C1-metabolism in Xanthobacter strain 25a was studied during growth of the organism on acetate, formate and methanol in chemostat cultures. No activity of methanol dehydrogenase (MDH), formate dehydrogenase (FDS) or ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisC/O) could be

  17. Interpretation of Post-operative Distal Humerus Radiographs After Internal Fixation: Prediction of Later Loss of Fixation

    NARCIS (Netherlands)

    Claessen, F.M.; Stoop, N.; Doornberg, J.N.; Guitton, T.G.; Bekerom, M.P. van den; Ring, D.; Biert, J.; et al.,

    2016-01-01

    PURPOSE: Stable fixation of distal humerus fracture fragments is necessary for adequate healing and maintenance of reduction. The purpose of this study was to measure the reliability and accuracy of interpretation of postoperative radiographs to predict which implants will loosen or break after

  18. A review on photo-thermal catalytic conversion of carbon dioxide

    Directory of Open Access Journals (Sweden)

    Ee Teng Kho

    2017-07-01

    Full Text Available The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a significant limiting factor in the system's performance. By utilising energy from the sun, through a range of key routes, this limitation can be overcome. In this review, we present a comprehensive and critical overview of the potential routes to harvest the sun's energy, primarily through solar-thermal technologies and plasmonic resonance effects. Focusing on the localised heating approach, this review shortlists and compares viable catalysts for the photo-thermal catalytic conversion of carbon dioxide. Further, the pathways and potential products of different carbon dioxide conversion routes are outlined with the reverse water gas shift, methanation, and methanol synthesis being of key interest. Finally, the challenges in implementing such systems and the outlook to the future are detailed. Keywords: Carbon dioxide conversion, Photo-thermal, Plasmonic catalysis, Solar thermal

  19. Forest response to carbon dioxide

    International Nuclear Information System (INIS)

    Pitelka, L.

    1992-01-01

    It has been suggested that planting trees could help slow the buildup of carbon dioxide in the atmosphere. Since elevated levels of CO 2 are known to enhance photosynthesis and growth in many plants, it is possible that trees could become progressively more effective in storing carbon as atmospheric CO 2 increases. However, early results from experiments with ponderosa and loblolly pines indicate that the relationship between tree growth and rising CO 2 concentrations may be more complex than scientists once thought. In these experiments, the response to elevated CO 2 has been highly dependent both on species and on mineral nutrient levels in the soil. Further work is necessary to clarify the mechanisms involved. This research will ultimately contribute to an integrated model for predicting forest ecosystem response to elevated CO 2

  20. Electrochemical processing of carbon dioxide.

    Science.gov (United States)

    Oloman, Colin; Li, Hui

    2008-01-01

    With respect to the negative role of carbon dioxide on our climate, it is clear that the time is ripe for the development of processes that convert CO(2) into useful products. The electroreduction of CO(2) is a prime candidate here, as the reaction at near-ambient conditions can yield organics such as formic acid, methanol, and methane. Recent laboratory work on the 100 A scale has shown that reduction of CO(2) to formate (HCO(2)(-)) may be carried out in a trickle-bed continuous electrochemical reactor under industrially viable conditions. Presuming the problems of cathode stability and formate crossover can be overcome, this type of reactor is proposed as the basis for a commercial operation. The viability of corresponding processes for electrosynthesis of formate salts and/or formic acid from CO(2) is examined here through conceptual flowsheets for two process options, each converting CO(2) at the rate of 100 tonnes per day.

  1. Nongovernmental valorization of carbon dioxide

    International Nuclear Information System (INIS)

    Petersen, Gene; Viviani, Donn; Magrini-Bair, Kim; Kelley, Stephen; Moens, Luc; Shepherd, Phil; DuBois, Dan

    2005-01-01

    Carbon dioxide (CO 2 ) is considered the largest contributor to the greenhouse gas effect. Most attempts to manage the flow of CO 2 or carbon into our environment involve reducing net emissions or sequestering the gas into long-lived sinks. Using CO 2 as a chemical feedstock has a long history, but using it on scales that might impact the net emissions of CO 2 into the atmosphere has not generally been considered seriously. There is also a growing interest in employing our natural biomes of carbon such as trees, vegetation, and soils as storage media. Some amelioration of the net carbon emissions into the atmosphere could be achieved by concomitant large withdrawals of carbon. This report surveys the potential and limitations in employing carbon as a resource for organic chemicals, fuels, inorganic materials, and in using the biome to manage carbon. The outlook for each of these opportunities is also described

  2. Erbium diffusion in titanium dioxide

    Directory of Open Access Journals (Sweden)

    Louise Basse

    2017-04-01

    Full Text Available The diffusivity of erbium in the anatase phase of titanium dioxide (TiO2 has been studied for various temperatures ranging from 800 °C to 1, 000 °C. Samples of TiO2, with a 10 nm thick buried layer containing 0.5 at% erbium, were fabricated by radio-frequency magnetron sputtering and subsequently heat treated. The erbium concentration profiles were measured by secondary ion mass spectrometry, allowing for determination of the temperature-dependent diffusion coefficients. These were found to follow an Arrhenius law with an activation energy of ( 2.1 ± 0.2 eV. X-ray diffraction revealed that the TiO2 films consisted of polycrystalline grains of size ≈ 100 nm.

  3. Clinical efficacy and safety of limited internal fixation combined with external fixation for Pilon fracture: A systematic review and meta-analysis

    OpenAIRE

    Zhang, Shaobo; Zhang, Yibao; Wang, Shenghong; Zhang, Hua; Liu, Peng; Zhang, Wei; Ma, Jing-Lin; Wang, Jing

    2017-01-01

    Purpose: To compare the clinical efficacy and complications of limited internal fixation combined with external fixation (LIFEF) and open reduction and internal fixation (ORIF) in the treatment of Pilon fracture. Methods: We searched databases including Pubmed, Embase, Web of science, Cochrane Library and China Biology Medicine disc for the studies comparing clinical efficacy and complications of LIFEF and ORIF in the treatment of Pilon fracture. The clinical efficacy was evaluated by the ...

  4. Analysis and an overview of fixators in medicine and the methods of processing materials for producing fixators

    Directory of Open Access Journals (Sweden)

    Dalibor Milojko Đenadić

    2013-06-01

    Full Text Available The fixator is a medical device that provides support to fractured biological structures. Metal biomaterials are mainly used for replacing broken or damaged hard tissues such as bones because of their high strenght, toughness and corrosion resistance. Materials such as stainless steel, titanium and aluminium alloys (Ti-6Al-4V, cobalt and chromium alloys, composite materials and other biocompatible materials are used in orthopedy for the stabilization of connective tissue injuries or as a substitute for the bone tissues. Fixators are classified according to the place of installation to external and internal fixators. Widely used medical fixators are pins, rods plates, screws, pipes, wires, nails and external fixators. Conventional and non-conventional methods of processing are used in the production process for all types of fixators. Introduction Fixators are medical devices manufactured to support damaged biological structures. In the field of orthopedic surgery that deals with skeletal disorders such as bone, spine, joints, muscles and tendons injuries and diseases, various metals, titanium and cobalt alloys etc. are used to stabilize the supporting tissue injuries or as a substitute for bone tissues. Metallic implants are frequently used in orthopedic surgery as joint prosthesis (hip, knee and elbow fracture fixation devices (plates, screws, external fixators and devices for the fixation of the spine. In principle, fixators are devided into external and internal ones, depending on the place of installation (outside or inside the body. The most common types of medical fixators are pins, rods and plates. This paper presents some of the most common materials used for the production of fixators, their processing and possibilties of use in medicine for various purposes. Types of fixators and materials used for their production Nowadays, biocompatible materials are usually used for the production of fixators and implants. These materials show good

  5. Carbon dioxide cleaning pilot project

    International Nuclear Information System (INIS)

    Knight, L.; Blackman, T.E.

    1994-01-01

    In 1989, radioactive-contaminated metal at the Rocky Flats Plant (RFP) was cleaned using a solvent paint stripper (Methylene chloride). One-third of the radioactive material was able to be recycled; two-thirds went to the scrap pile as low-level mixed waste. In addition, waste solvent solutions also required disposal. Not only was this an inefficient process, it was later prohibited by the Resource Conservation and Recovery Act (RCRA), 40 CFR 268. A better way of doing business was needed. In the search for a solution to this situation, it was decided to study the advantages of using a new technology - pelletized carbon dioxide cleaning. A proof of principle demonstration occurred in December 1990 to test whether such a system could clean radioactive-contaminated metal. The proof of principle demonstration was expanded in June 1992 with a pilot project. The purpose of the pilot project was three fold: (1) to clean metal so that it can satisfy free release criteria for residual radioactive contamination at the Rocky Flats Plant (RFP); (2) to compare two different carbon dioxide cleaning systems; and (3) to determine the cost-effectiveness of decontamination process in a production situation and compare the cost of shipping the metal off site for waste disposal. The pilot project was completed in August 1993. The results of the pilot project were: (1) 90% of those items which were decontaminated, successfully met the free release criteria , (2) the Alpheus Model 250 was selected to be used on plantsite and (3) the break even cost of decontaminating the metal vs shipping the contaminated material offsite for disposal was a cleaning rate of 90 pounds per hour, which was easily achieved

  6. The implications of carbon dioxide and methane exchange for the heavy mitigation RCP2.6 scenario under two metrics

    NARCIS (Netherlands)

    Huntingford, Chris; Lowe, Jason A.; Howarth, Nicholas; Bowerman, Niel H.A.; Gohar, Laila K.; Otto, Alexander; Lee, David S.; Smith, Stephen M.; den Elzen, Michel G.J.; van Vuuren, Detlef P.; Millar, Richard J.; Allen, Myles R.

    2015-01-01

    Greenhouse gas emissions associated with Representative Concentration Pathway RCP2.6 could limit global warming to around or below a 2°C increase since pre-industrial times. However this scenario implies very large and rapid reductions in both carbon dioxide (CO2) and non-CO2 emissions, and suggests

  7. Role of photoexcited nitrogen dioxide chemistry on ozone formation and emission control strategy over the Pearl River Delta, China

    Science.gov (United States)

    A new hydroxyl radical formation pathway via photo-excited nitrogen dioxide chemistry is incorporated into a chemistry-only box model as well as a 3D air quality model to examine its potential role on ozone formation and emission control strategy over the Pearl River Delta region...

  8. Nanoparticulate cerium dioxide and cerium dioxide-titanium dioxide composite thin films on glass by aerosol assisted chemical vapour deposition

    International Nuclear Information System (INIS)

    Qureshi, Uzma; Dunnill, Charles W.; Parkin, Ivan P.

    2009-01-01

    Two series of composite thin films were deposited on glass by aerosol assisted chemical vapour deposition (AACVD)-nanoparticulate cerium dioxide and nanoparticulate cerium dioxide embedded in a titanium dioxide matrix. The films were analysed by a range of techniques including UV-visible absorption spectroscopy, X-ray diffraction, scanning electron microscopy and energy dispersive analysis by X-rays. The AACVD prepared films showed the functional properties of photocatalysis and super-hydrophilicity. The CeO 2 nanoparticle thin films displaying photocatalysis and photo-induced hydrophilicity almost comparable to that of anatase titania.

  9. Glue versus suture for mesh fixation in inguinal hernia repair.

    Science.gov (United States)

    Chandrasekar, Shruthi; Jeyakumar, S; Ganapathy, Tharun

    2018-03-22

    Inguinal hernia is one of the most common surgical problem presenting to the surgical OPD. Surgery is the mainstay of treatment for inguinal hernia today. Surgery for inguinal hernia has undergone a great evolution over a period of several centuries. Lichenstein's tension free hernioplasty is the one of the first surgeries taught to a surgical resident. The main aim of surgeries in this era is to give the best possible results with the least possible pain, scar and time. This has given rise to so many modifications to the classical Lichenstein's procedure and also to laparoscopic hernioplasty. Pain after inguinal hernia surgery is found to be debilitating and altering the quality of life in several patients, which has been attributed to the traumatic fixation of the mesh with sutures. This has paved way to the development of various atraumatic methods of fixation, tissue glue is one such development. Hence this study, to compare traumatic and atraumatic methods of mesh fixation in inguinal hernia repair. The aim of this study was to compare suture fixation versus tissue glue fixation of the mesh in inguinal hernia repair. Primary objective was to compare the immediate and chronic post-operative pain. Secondary objective was to compare the time taken for the procedure by the two methods in use and also to compare the presence of any complications. and methodology: This study was done in the General Surgery department of XXX hospital, medical college and research centre, kattangulathur after Ethics committee clearance. It is a single blinded study. The study was done on 51 patients consenting for the study and meeting the inclusion criterias from the period of March 2016 to August 2017 out of which 26 were selected for glue mesh fixation and 25 for suture mesh fixation according to simple randomization. The suture group patients underwent classical Lichenstein's tension free hernioplasty and the glue group underwent Lichenstein's hernioplasty with glue where dots of

  10. The influence on the contact condition and initial fixation stability of the main design parameters of a self-expansion type anterior cruciate ligament fixation device

    International Nuclear Information System (INIS)

    Kim, Jong Dae; Oh, Chae Youn; Kim, Cheol Sang

    2008-01-01

    This paper proposes a self-expansion type anterior cruciate ligament fixation device. The proposed fixation device provides graft fixation force by maintaining contact with the bone tunnel. Since the device maintains contact with the bone tunnel by the force that expands by the self-driven elastic force of the device, the main design parameters that determine the performance of this device are the ring thickness and expansion angle. This paper develops the three-dimensional finite element models of the fixation device and bone. By simulation with the developed finite element model, this paper studies the influence of the main design parameters of the device on the maximum stress around the ring when grasping the fixation device. Through the analysis of the stress on the bone tunnel wall when the fixation device comes in contact with the bone tunnel, this paper shows the influence of the main design parameters of the fixation device on the contact condition. In addition, through the analysis of the migration that occur upon application of the pull-out force, this paper studies the influence of the main design parameters on the initial fixation stability of the fixation device

  11. The influence on the contact condition and initial fixation stability of the main design parameters of a self-expansion type anterior cruciate ligament fixation device

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Dae [Jeonju University, Jeonju (Korea, Republic of); Oh, Chae Youn; Kim, Cheol Sang [Chonbuk National University, Jeonju (Korea, Republic of)

    2008-12-15

    This paper proposes a self-expansion type anterior cruciate ligament fixation device. The proposed fixation device provides graft fixation force by maintaining contact with the bone tunnel. Since the device maintains contact with the bone tunnel by the force that expands by the self-driven elastic force of the device, the main design parameters that determine the performance of this device are the ring thickness and expansion angle. This paper develops the three-dimensional finite element models of the fixation device and bone. By simulation with the developed finite element model, this paper studies the influence of the main design parameters of the device on the maximum stress around the ring when grasping the fixation device. Through the analysis of the stress on the bone tunnel wall when the fixation device comes in contact with the bone tunnel, this paper shows the influence of the main design parameters of the fixation device on the contact condition. In addition, through the analysis of the migration that occur upon application of the pull-out force, this paper studies the influence of the main design parameters on the initial fixation stability of the fixation device

  12. The methionine salvage pathway in Bacillus subtilis

    Directory of Open Access Journals (Sweden)

    Danchin Antoine

    2002-04-01

    Full Text Available Abstract Background Polyamine synthesis produces methylthioadenosine, which has to be disposed of. The cell recycles it into methionine through methylthioribose (MTR. Very little was known about MTR recycling for methionine salvage in Bacillus subtilis. Results Using in silico genome analysis and transposon mutagenesis in B. subtilis we have experimentally uncovered the major steps of the dioxygen-dependent methionine salvage pathway, which, although similar to that found in Klebsiella pneumoniae, recruited for its implementation some entirely different proteins. The promoters of the genes have been identified by primer extension, and gene expression was analyzed by Northern blotting and lacZ reporter gene expression. Among the most remarkable discoveries in this pathway is the role of an analog of ribulose diphosphate carboxylase (Rubisco, the plant enzyme used in the Calvin cycle which recovers carbon dioxide from the atmosphere as a major step in MTR recycling. Conclusions A complete methionine salvage pathway exists in B. subtilis. This pathway is chemically similar to that in K. pneumoniae, but recruited different proteins to this purpose. In particular, a paralogue or Rubisco, MtnW, is used at one of the steps in the pathway. A major observation is that in the absence of MtnW, MTR becomes extremely toxic to the cell, opening an unexpected target for new antimicrobial drugs. In addition to methionine salvage, this pathway protects B. subtilis against dioxygen produced by its natural biotope, the surface of leaves (phylloplane.

  13. Complications Using Bioabsorbable Cross-Pin Femoral Fixation: A Case Report and Review of the Literature

    Directory of Open Access Journals (Sweden)

    Saqib Hasan

    2011-01-01

    Full Text Available The use of bioabsorbable cross-pin transcondylar fixation has remained a viable option for femoral fixation in anterior cruciate ligament reconstruction. Although numerous biomechanical studies have demonstrated high fixation strength and minimal slippage with use of this method of fixation, there have been increasing reports of a variety of clinical complications associated with these implants. We reviewed the literature for all complications associated with the Bio-TransFix implant and present a case report of a patient status after ACL reconstruction using Bio-TransFix cross-pin femoral fixation with iliotibial band friction syndrome from a broken cross-pin four month post-operatively.

  14. Fixation of a human rib by an intramedullary telescoping splint anchored by bone cement.

    Science.gov (United States)

    Liovic, Petar; Šutalo, Ilija D; Marasco, Silvana F

    2016-09-01

    A novel concept for rib fixation is presented that involves the use of a bioresorbable polymer intramedullary telescoping splint. Bone cement is used to anchor each end of the splint inside the medullary canal on each side of the fracture site. In this manner, rib fixation is achieved without fixation device protrusion from the rib, making the splint completely intramedullary. Finite element analysis is used to demonstrate that such a splint/cement composite can preserve rib fixation subjected to cough-intensity force loadings. Computational fluid dynamics and porcine rib experiments were used to study the anchor formation process required to complete the fixation.

  15. Novel anterior cruciate ligament graft fixation device reduces slippage

    Directory of Open Access Journals (Sweden)

    Lopez MJ

    2013-05-01

    Full Text Available Mandi J Lopez,1 Allen Borne,2 W Todd Monroe,3 Prakash Bommala,1 Laura Kelly,1 Nan Zhang11Laboratory for Equine and Comparative Orthopedic Research, Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, 2Louisiana State University, New Orleans Health Sciences Center, School of Medicine, New Orleans, 3Department of Biological and Agricultural Engineering, Agricultural Center, Louisiana State University, Baton Rouge, LA, USAAbstract: Clinically significant laxity occurs in 10%–30% of knees after anterior cruciate ligament reconstruction. Graft slippage and tension loss at the hamstring graft tibial fixation site during and after reconstruction surgery contribute to postoperative joint laxity and are detrimental to long-term knee stability and graft properties. Limiting graft slippage will reduce associated complications. We sought to compare the in vitro mechanical properties and in vivo joint stabilization, postoperative limb use, and graft incorporation of the novel GraftGrab™ (GG device designed to reduce hamstring graft tibial fixation slippage with the commercially available bioabsorbable Bio-Post™ and spiked washer (BP. Mechanical testing was performed on canine tibia-hamstring graft constructs to quantify initial fixation properties. In vivo joint stabilization, postoperative limb use and graft incorporation of hamstring graft reconstructions were determined in a canine model. Outcomes included tibial translation and ground reaction forces preoperatively and 4 and 8 weeks postoperatively, three-dimensional graft and bone tunnel dimensions at the latter two time points, and graft-bone microstructure, as well as mechanical properties 8 weeks after implantation. Immediately after fixation, all grafts slipped from the BP constructs versus about 30% of GG constructs. In vivo limb use remained low, and tibial translation increased with time in the BP cohort. These results together

  16. EXPERIMENTAL APPROVAL OF COMBINED FIXATION FOR FEMUR LENGTHENING

    Directory of Open Access Journals (Sweden)

    M. A. Stepanov

    2017-01-01

    Full Text Available Elimination of congenital shortening of lower limb still remains a complex and unsolved orthopaedic task which requires an improved fixation technique as well as adjusted tactics of treatment and rehabilitation procedures.Purpose of the study — experimental approval of femur lengthening technique by external fixation with Ilizarov apparatus and internal fixation by plate.Materials and methods. Femur lengthening was performed in 6 mongrel dogs. Average animal age was 1,5±0,3 years, average weight — 20±5 kg, femur length — 22±2 sm. External apparatus with two supports and a titanium plate of an original design were applied under general anesthesia on the right femur of animals. Lengthening was performed manually at a rate of1 mm per day in 4 stages at a distance of 10% from initial segment length. External apparatus was removed on the last day of distraction after locking the plate. X-ray examination was done on the day of surgery, in 7, 14 and 25 days from the onset of distraction as well as in 14, 30, 60 and 90 days after completion of distraction and removal of external apparatus. Three animals were taken out of experiment in 30 days of fixation, remaining three animals — in 90 days. After euthanasia the authors performed autopsy of the organic femur complex and tissues contacting the plate.Results. The use of operated limb was not restricted during the whole distraction period. The authors observed first roentgenological signs of distraction osteogenesis on 7th day of lengthening. By the end of distraction period, at 25th day, shadows of regenerates demonstrated longitudinal striated structures in all cases. Median lucency area of 1–5 mm was located diagonally and across the regenerate or was intermittent. In 60 days of fixation X-rays demonstrated homogeneous regenerate. External fixation index was 13,9±1,5 days/sm (p≤0,05. The authors observed no cases of implants fracture or deformity during the experiment

  17. Deepwater Nitrogen Fixation: Who's Doing it, Where, and Why?

    Science.gov (United States)

    Montoya, J. P.; Weber, S.; Vogts, A.; Voss, M.; Saxton, M.; Joye, S. B.

    2016-02-01

    Nitrogen availability frequently limits marine primary production and N2-fixation plays an important role in supporting biological production in surface waters of many oligotrophic regions. Although subsurface waters typically contain high concentrations of nitrate and other nutrients, measurements from a variety of oceanic settings show measurable, and at times high rates of N2-fixation in deep, dark waters below the mixed layer. We have explored the distribution of N2-fixation throughout the water column of the Gulf of Mexico (GoM) during a series of cruises beginning shortly after the Deepwater Horizon (DWH) spill in 2010 and continuing at roughly annual intervals. These cruises allowed us to sample oligotrophic waters across a range of depths, and to explore the connections between the C and N cycles mediated by release of oil and gas (petrocarbon) from natural seeps as well as anthropogenic sources (e.g., the DWH). We used stable isotope abundances (15N and 13C) in particles and zooplankton in combination with experimental measurements of N2-fixation and CH4 assimilation to assess the contribution of oil- and gas-derived C to the pelagic food web, and the impact of CH4 releases on the pelagic C and N cycles. Our isotopic measurements document the movement of petrocarbon into the pelagic food web, and our experiments revealed that high rates of N2-fixation were widespread in deep water immediately after the DWH incident, and restricted to the vicinity of natural seeps in subsequent years. Unfortunately, these approaches provided no insight into the organisms actually responsible for N2-fixation and CH4-assimilation. We used nano-scale Secondary Ion Mass Spectrometry (nanoSIMS) to image the organisms responsible for these processes, and molecular approaches to explore the diversity of methanotrophs and diazotrophs present in the system. The ability to resolve isotopic distributions on the scale of individual cells is a critical part of bridging the gap between

  18. Seasonal patterns of periphyton nitrogen fixation in calcareous wetlands

    Science.gov (United States)

    Liao, X.; Inglett, P.

    2011-12-01

    Periphyton mats are an ecologically important component of the Everglades ecosystem and plays various vital ecological functions. However, nitrogen fixation of periphyton, has received little attention throughout much of the Everglades system. The objective of this study was to characterize the seasonal pattern of periphyton N2 fixation in the Hole-in-the-Donut (HID) of Florida Everglades, where farmed marl prairie wetlands have been restored through complete soil removal (CSR) to reduce nutrient levels. Two restored areas (i.e., cleared in 2000 and 2003) and a reference (natural and unfarmed) marl prairie wetland sites were selected in the HID. Seven times of sampling were performed across the wet and dry season during the 2010 and 2011. The annual fixed nitrogen was approximately 0.4gN m-2 yr-1 in the restored sites which was higher in the reference site (~0.2gN m-2 yr-1). All the three sites showed similar seasonal patterns of N2 fixation that is higher values were observed in the wet season; but the peak value was one month later in reference sits (i.e., September) comparing to the restored areas (i.e., July). The peak of periphyton AR rates in the 2000- and 2003-restored areas appeared in July (i.e., wet season) within the range of 20-79 nmols g-1dw h-1 and 31-53nmols g-1dw h-1, respectively. In contrast, the peak of reference site was observed in September with the range of 2-5 nmols g-1dw h-1. Stable N isotopic ratios (i.e., δ15N) also varied with time but didn't show consistent seasonal pattern as nitrogen fixation. N2 fixation positively correlated with periphyton total phosphorus (TP) and negatively correlated with total nitrogen and phosphorus molar ratios (TN:TP), indicating that N2 fixation would be a indicator of nutrient limitation. In general, δ15N was negatively correlated with nitrogenase activity but the correlation became weakened in the wet season, especially in the flooded July and September, which would be explained by other environmental

  19. Clinical comparison between the retromandibular approach for reduction and fixation and endoscope-assisted open reduction and internal fixation for mandibular condyle fractures.

    Science.gov (United States)

    Nogami, Shinnosuke; Takahashi, Tetsu; Yamauchi, Kensuke; Miyamoto, Ikuya; Kaneuji, Takeshi; Yamamoto, Noriaki; Yoshiga, Daigo; Yamashita, Yoshihiro

    2012-11-01

    Endoscope-assisted transoral open reduction and internal fixation (EAORIF) for mandibular condyle fractures has recently become popular because it is minimally invasive, provides excellent visibility without a large incision, and reduces surgical scarring and the risk of facial nerve injury. This report describes a retrospective clinical study that compared certain clinical parameters, including postoperative function, between the retromandibular (RM) approach and EAORIF. Fifteen patients were treated by the RM approach, whereas 15 underwent EAORIF between July 2006 and September 2011 at Kyushu Dental College, Japan. Clinical indices comprised fracture line, fracture type, number of plates used, surgical duration, bleeding amount, and functional items, including maximum interincisal opening, mandibular deviation on the opening pathway, malocclusion, facial paresthesia, and temporomandibular joint pain and clicking. The areas subjected to either approach included lower neck and subcondyle. The RM approach was used for mandibular condyle fractures with dislocation of a small bone segment. Both groups used 2 plates in all cases. Surgical duration, maximum interincisal opening, mandibular deviation, occlusion, and temporomandibular joint function at 6 months after surgery were comparable between groups. The average bleeding amount in the EAORIF group was greater than in the RM group. One patient from the RM group developed facial paresthesia that persisted for 6 months after surgery. It was concluded that surgical treatment was suitable for fractures of the lower neck and subcondylar. Both procedures showed good results in the functional items of this study.

  20. Nitrogen Fixation by Gliding Arc Plasma: Better Insight by Chemical Kinetics Modelling.

    Science.gov (United States)

    Wang, Weizong; Patil, Bhaskar; Heijkers, Stjin; Hessel, Volker; Bogaerts, Annemie

    2017-05-22

    The conversion of atmospheric nitrogen into valuable compounds, that is, so-called nitrogen fixation, is gaining increased interest, owing to the essential role in the nitrogen cycle of the biosphere. Plasma technology, and more specifically gliding arc plasma, has great potential in this area, but little is known about the underlying mechanisms. Therefore, we developed a detailed chemical kinetics model for a pulsed-power gliding-arc reactor operating at atmospheric pressure for nitrogen oxide synthesis. Experiments are performed to validate the model and reasonable agreement is reached between the calculated and measured NO and NO 2 yields and the corresponding energy efficiency for NO x formation for different N 2 /O 2 ratios, indicating that the model can provide a realistic picture of the plasma chemistry. Therefore, we can use the model to investigate the reaction pathways for the formation and loss of NO x . The results indicate that vibrational excitation of N 2 in the gliding arc contributes significantly to activating the N 2 molecules, and leads to an energy efficient way of NO x production, compared to the thermal process. Based on the underlying chemistry, the model allows us to propose solutions on how to further improve the NO x formation by gliding arc technology. Although the energy efficiency of the gliding-arc-based nitrogen fixation process at the present stage is not comparable to the world-scale Haber-Bosch process, we believe our study helps us to come up with more realistic scenarios of entering a cutting-edge innovation in new business cases for the decentralised production of fertilisers for agriculture, in which low-temperature plasma technology might play an important role. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Regional constraints to biological nitrogen fixation in post-fire forest communities

    Science.gov (United States)

    Yelenik, Stephanie; Perakis, Steven S.; Hibbs, David

    2013-01-01

    Biological nitrogen fixation (BNF) is a key ecological process that can restore nitrogen (N) lost in wildfire and shape the pace and pattern of post-fire forest recovery. To date, there is limited information on how climate and soil fertility interact to influence different pathways of BNF in early forest succession. We studied asymbiotic (forest floor and soil) and symbiotic (the shrub Ceanothus integerrimus) BNF rates across six sites in the Klamath National Forest, California, USA. We used combined gradient and experimental phosphorus (P) fertilization studies to explore cross-site variation in BNF rates and then related these rates to abiotic and biotic variables. We estimate that our measured BNF rates 22 years after wildfire (6.1–12.1 kg N·ha-1·yr-1) are unlikely to fully replace wildfire N losses. We found that asymbiotic BNF is P limited, although this is not the case for symbiotic BNF in Ceanothus. In contrast, Ceanothus BNF is largely driven by competition from other vegetation: in high-productivity sites with high potential evapotranspiration (Et), shrub biomass is suppressed as tree biomass increases. Because shrub biomass governed cross-site variation in Ceanothus BNF, this competitive interaction led to lower BNF in sites with high productivity and Et. Overall, these results suggest that the effects of nutrients play a larger role in driving asymbiotic than symbiotic fixation across our post-fire sites. However, because symbiotic BNF is 8–90x greater than asymbiotic BNF, it is interspecific plant competition that governs overall BNF inputs in these forests.

  2. Ball-joint versus single monolateral external fixators for definitive treatment of tibial shaft fractures.

    Science.gov (United States)

    Beltsios, Michail; Mavrogenis, Andreas F; Savvidou, Olga D; Karamanis, Eirineos; Kokkalis, Zinon T; Papagelopoulos, Panayiotis J

    2014-07-01

    To compare modular monolateral external fixators with single monolateral external fixators for the treatment of open and complex tibial shaft fractures, to determine the optimal construct for fracture union. A total of 223 tibial shaft fractures in 212 patients were treated with a monolateral external fixator from 2005 to 2011; 112 fractures were treated with a modular external fixator with ball-joints (group A), and 111 fractures were treated with a single external fixator without ball-joints (group B). The mean follow-up was 2.9 years. We retrospectively evaluated the operative time for fracture reduction with the external fixator, pain and range of motion of the knee and ankle joints, time to union, rate of malunion, reoperations and revisions of the external fixators, and complications. The time for fracture reduction was statistically higher in group B; the rate of union was statistically higher in group B; the rate of nonunion was statistically higher in group A; the mean time to union was statistically higher in group A; the rate of reoperations was statistically higher in group A; and the rate of revision of the external fixator was statistically higher in group A. Pain, range of motion of the knee and ankle joints, rates of delayed union, malunion and complications were similar. Although modular external fixators are associated with faster intraoperative fracture reduction with the external fixator, single external fixators are associated with significantly better rates of union and reoperations; the rates of delayed union, malunion and complications are similar.

  3. Time Savings and Surgery Task Load Reduction in Open Intraperitoneal Onlay Mesh Fixation Procedure

    Directory of Open Access Journals (Sweden)

    Sanjoy Roy

    2015-01-01

    Full Text Available Background. This study assessed the reduction in surgeon stress associated with savings in procedure time for mechanical fixation of an intraperitoneal onlay mesh (IPOM compared to a traditional suture fixation in open ventral hernia repair. Study Design. Nine general surgeons performed 36 open IPOM fixation procedures in porcine model. Each surgeon conducted two mechanical (using ETHICON SECURESTRAPTM Open and two suture fixation procedures. Fixation time was measured using a stopwatch, and related surgeon stress was assessed using the validated SURG-TLX questionnaire. T-tests were used to compare between-group differences, and a two-sided 95% confidence interval for the difference in stress levels was established using nonparametric methodology. Results. The mechanical fixation group demonstrated an 89.1% mean reduction in fixation time, as compared to the suture group (p<0.00001. Surgeon stress scores measured using SURG-TLX were 55.5% lower in the mechanical compared to the suture fixation group (p<0.001. Scores in five of the six sources of stress were significantly lower for mechanical fixation. Conclusions. Mechanical fixation with ETHICON SECURESTRAPTM Open demonstrated a significant reduction in fixation time and surgeon stress, which may translate into improved operating efficiency, improved performance, improved surgeon quality of life, and reduced overall costs of the procedure.

  4. Reaction of yttrium polonides with carbon dioxide

    International Nuclear Information System (INIS)

    Abakumov, A.S.; Khokhlov, A.D.; Reznikova, N.F.

    1986-01-01

    It has been proved that heating of yttrium and tantalum in carbon dioxide to 500 and 800 0 C alters the gas phase composition, causing formation of carbon monoxide and reduction of oxygen content. A study of the thermal stability of yttrium polonides in carbon dioxide showed that yttrium sesqui- and monopolonides decompose at 400-430 0 C. The temperature dependence of the vapor pressure of polonium obtained upon decomposition of the referred polonides has been determined in a carbon dioxide environment radiotensometrically. The enthalpy of the process calculated from this dependence is close to the enthalpy of vaporization of elemental polonium in vacuo. The mechanism of the reactions has been suggested

  5. Small bowel obstruction in percutaneous fixation of traumatic pelvic fractures

    Directory of Open Access Journals (Sweden)

    Roberto Bini

    2013-01-01

    Full Text Available The use of external fixation for the initial treatment of unstable, complex pelvic injuries with hemodynamic instability remains an effective treatment for multiply injured patients. Bowel entrapment within a pelvic fracture is a rarely reported, potentially fatal complication. Here, we report a polytrauma patient with pelvic fractures who developed an intestinal obstruction after an external fixation. At an explorative laparotomy, we found an ileum segment trapped in the sacral fracture. Reported cases of bowel entrapment in pelvic fractures, especially in sacral fractures, are exceedingly rare. The diagnosis is often delayed due to difficulty distinguishing entrapment from the more common adynamic ileus. In conclusion, clinicians and radiologists should be aware of this potentially lethal complication of pelvic fractures treatment. To exclude bowel entrapment, patients with persistent ileus or sepsis should undergo early investigations.

  6. Molecular nitrogen fixation and nitrogen cycle in nature

    Energy Technology Data Exchange (ETDEWEB)

    Virtanen, A I

    1952-01-01

    The origin of nitrogen oxides in the atmosphere is discussed. Evidently only a small proportion of the nitrate-and nitrite-nitrogen found in the precipitation is formed through electric discharges from molecular nitrogen, photochemical nitrogen fixation being probably of greater importance. Formation of nitrate nitrogen through atmospheric oxidation of nitrous oxide (N/sub 2/O) evaporating from the soil is also considered likely. Determination of nitrogen compounds at different altitudes is indispensable for gaining information of the N/sub 2/-fixation in the atmosphere and, in general, of the origin of nitrogen oxides and their decomposition. International cooperation is needed for this as well as for the quantitative determination of the nitrogen compounds removed from the soil by leaching and brought by waters into the seas.

  7. Bone graft materials in fixation of orthopaedic implants in sheep

    DEFF Research Database (Denmark)

    Babiker, Hassan

    2013-01-01

    Bone graft is widely used within orthopaedic surgery especially in revision joint arthroplasty and spine fusion. The early implant fixation in the revision situation of loose joint prostheses is important for the long-term survival. Bone autograft has been considered as gold standard in many...... orthopaedic procedures, whereas allograft is the gold standard by replacement of extensive bone loss. However, the use of autograft is associated with donor site morbidity, especially chronic pain. In addition, the limited supply is a significant clinical challenge. Limitations in the use of allograft include...... the risk of bacterial contamination and disease transmission as well as non-union and poor bone quality. Other bone graft and substitutes have been considered as alternative in order to improve implant fixation. Hydroxyapatite and collagen type I composite (HA/Collagen) have the potential in mimicking...

  8. Optimising biological N2 fixation by legumes in farming systems

    International Nuclear Information System (INIS)

    Hardarson, Gudni; Atkins, Craig

    2001-01-01

    Whether grown as pulses for grain, as green manure, as pastures or as the tree components of agro-forestry systems, the value of leguminous crops lies in their ability to fix atmospheric N 2 , so reducing the use of expensive fertiliser N and enhancing soil fertility. N 2 fixing legumes provide the basis for developing sustainable farming systems that incorporate integrated nutrient management. By exploiting the stable nitrogen isotope 15 N, it has been possible to reliably measure rates of N 2 fixation in a wide range of agro-ecological field situations involving many leguminous species. The accumulated data demonstrate that there is a wealth of genetic diversity among legumes and their Rhizobium symbionts which can be used to enhance N 2 fixation. Practical agronomic and microbiological means to maximise N inputs by legumes have also been identified. (author)

  9. Fixation Of Mo In Uranium Leach Liquor By Activated Carbon

    International Nuclear Information System (INIS)

    Mainar, S.; Guswita, A.; Erni, R.A.; Susilaningtyas

    1996-01-01

    The use of activated carbon for Mo fixation by bulk system is reported. Several factors influencing the fixation process were examined, including contact time, carbon particle size, carbon porosity and the effect of other elements present in Mo containing solutions. Experimental data showed that an adsorption equilibrium of Mo on of activated carbon and 0,85 to 1,18 mm of carbon particle size under forced-convection mass transfer in 100 ml solution that contains + 0,56 m mol of Mo and +. 0,25 m mol Of U was reached after 6 hours period. Under those conditions, about 0,50 m mol of Mo and 0,026 m mol of U were adsorbed into carbon. High concentration of rare earth elements decreased Mo adsorption, hence, the use of activated carbon was not effective to separate Mo from the digestion liquor of Rirang are where Mo was adsorbed, into the carbon + 34,5 %

  10. Monotest in the complement fixation test: the Chorus system

    Directory of Open Access Journals (Sweden)

    Laura Meli

    2009-06-01

    Full Text Available The complement fixation test (CFT is a method used for the detection of antibodies against pathogens of infectious diseases, it has been proved to be a useful diagnostic method in the detection of acute disease in many medical laboratories.The test performed manually is time consuming and needs very skilled personnel.This study evaluates the automated Chorus CFT system with 87 serum samples in comparison with manual method using Virion-Serion reagents, against a panel of antigens, such as Adenovirus, Influenza A and B virus, Respiratory Syncythial Virus, Parainfluenza Mix, Mycoplasma Pneumoniae, and Echinococcus. The Chorus system includes standardized reagents and a monotest device to perform the single assay. In comparison to the manual CFT method, the correlation is 91.6% (7/83.The results obtained show that the automated Chorus system can be applied for detecting complement fixation antibodies against different infectious disease agents.

  11. Scleral fixation of a single-piece multifocal intraocular lens.

    Science.gov (United States)

    Can, Ertugrul; Basaran, M Resat; Gül, Adem

    2013-01-01

    We describe an ab interno technique for injector implantation of a one-piece multifocal intraocular lens (IOL). Transscleral fixation of multifocal posterior chamber IOL implantation using an injector with ab interno technique was performed in an eye of a 9-year-old girl who had undergone pars plana lensectomy 2 years before for bilateral lens subluxation with unknown etiology. No major complications were encountered during a 3-month follow-up of the patient and excellent centration was observed during the follow-up period. Her preoperative best spectacle-corrected distance visual acuity of 20/32 improved to uncorrected distance visual acuity of 20/25. Closed-loop design of IOL served the function of eyelets and position of the IOL was provided using only a 2-point fixation. Intraoperative position adjustment of the IOL provided an excellent centralization of multifocal IOL.

  12. Fixational eye movement: a negligible source of dynamic aberration.

    Science.gov (United States)

    Mecê, Pedro; Jarosz, Jessica; Conan, Jean-Marc; Petit, Cyril; Grieve, Kate; Paques, Michel; Meimon, Serge

    2018-02-01

    To evaluate the contribution of fixational eye movements to dynamic aberration, 50 healthy eyes were examined with an original custom-built Shack-Hartmann aberrometer, running at a temporal frequency of 236Hz, with 22 lenslets across a 5mm pupil, synchronized with a 236Hz pupil tracker. A comparison of the dynamic behavior of the first 21 Zernike modes (starting from defocus) with and without digital pupil stabilization, on a 3.4s sequence between blinks, showed that the contribution of fixational eye movements to dynamic aberration is negligible. Therefore we highlighted the fact that a pupil tracker coupled to an Adaptive Optics Ophthalmoscope is not essential to achieve diffraction-limited resolution.

  13. [Effectiveness comparison of flexible fixation and rigid fixation in treatment of ankle pronation-external rotation fractures with distal tibiofibular syndesmosis].

    Science.gov (United States)

    Li, Yuewei; Zhang, Minghui; Li, Xiaorong; Chen, Xiaoyong; Deng, Jianlong

    2017-07-01

    To compare the effectiveness of flexible fixation and rigid fixation in the treatment of ankle pronation-external rotation fractures with distal tibiofibular syndesmosis. A retrospective analysis was made on the clinical data of 50 patients with ankle pronation-external rotation fractures and distal tibiofibular syndesmosis treated between January 2013 and December 2015. Suture-button fixation was used in 23 patients (flexible fixation group) and cortical screw fixation in 27 patients (rigid fixation group). There was no significant difference in age, gender, weight, side, fracture type, and time from trauma to surgery between 2 groups ( P >0.05). The operation time, medial clear space (MCS), tibiofibular clear space (TFCS), tibiofibular overlap (TFO), American Orthopaedic Foot and Ankle Society (AOFAS) score, and Foot and Ankle Disability Index (FADI) score were compared between 2 groups. The operation time was (83.0±9.1) minutes in the flexible fixation group and was (79.6±13.1) minutes in the rigid fixation group, showing no significant difference ( t =1.052, P =0.265). All patients achieved healing of incision by first intention. The patients were followed up 12-20 months (mean, 14 months). The X-ray films showed good healing of fracture in 2 groups. There was no screw fracture, delayed union or nounion. The fracture healing time was (12.1±2.5) months in the flexible fixation group and was (11.3±3.2) months in the rigid fixation group, showing no significant difference between 2 groups ( t =1.024, P =0.192). Reduction loss occurred after removal of screw in 2 cases of the rigid fixation group. At last follow-up, there was no significant difference in MCS, TFCS, TFO, AOFAS score and FADI score between 2 groups ( P >0.05). Suture-button fixation has similar effectiveness to screw fixation in ankle function and imaging findings, and flexible fixation has lower risk of reduction loss of distal tibiofibular syndesmosis than rigid fixation.

  14. 46 CFR 97.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 97.37-9 Section 97.37-9 Shipping... Markings for Fire and Emergency Equipment, Etc. § 97.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...

  15. 46 CFR 78.47-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 3 2010-10-01 2010-10-01 false Carbon dioxide alarm. 78.47-9 Section 78.47-9 Shipping... and Emergency Equipment, Etc. § 78.47-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” (b) [Reserved] ...

  16. 46 CFR 169.732 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 169.732 Section 169.732 Shipping... Control, Miscellaneous Systems, and Equipment Markings § 169.732 Carbon dioxide alarm. Each carbon dioxide alarm must be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED.” ...

  17. 46 CFR 196.37-9 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Carbon dioxide alarm. 196.37-9 Section 196.37-9 Shipping... Markings for Fire and Emergency Equipment, etc. § 196.37-9 Carbon dioxide alarm. (a) All carbon dioxide alarms shall be conspicuously identified: “WHEN ALARM SOUNDS—VACATE AT ONCE. CARBON DIOXIDE BEING...

  18. 46 CFR 108.627 - Carbon dioxide alarm.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Carbon dioxide alarm. 108.627 Section 108.627 Shipping... EQUIPMENT Equipment Markings and Instructions § 108.627 Carbon dioxide alarm. Each carbon dioxide alarm must be identified by marking: “WHEN ALARM SOUNDS VACATE AT ONCE. CARBON DIOXIDE BEING RELEASED” next to...

  19. Fixation of zygomatic and mandibular fractures with biodegradable plates

    OpenAIRE

    Degala, Saikrishna; Shetty, Sujeeth; Ramya, S

    2013-01-01

    Context: In this prospective study, 13 randomly selected patients underwent treatment for zygomatic?complex fractures (2 site fractures) and mandibular fractures using 1.5 / 2 / 2.5-mm INION CPS biodegradable plates and screws. Aims: To assess the fixation of zygomatic-complex and mandibular fractures with biodegradable copolymer osteosynthesis system. Materials and Methods: In randomly selected 13 patients, zygomatic-complex and mandibular fractures were plated using resorbable plates and sc...

  20. Fixation of zygomatic and mandibular fractures with biodegradable plates.

    Science.gov (United States)

    Degala, Saikrishna; Shetty, Sujeeth; Ramya, S

    2013-01-01

    In this prospective study, 13 randomly selected patients underwent treatment for zygomatic-complex fractures (2 site fractures) and mandibular fractures using 1.5 / 2 / 2.5-mm INION CPS biodegradable plates and screws. To assess the fixation of zygomatic-complex and mandibular fractures with biodegradable copolymer osteosynthesis system. In randomly selected 13 patients, zygomatic-complex and mandibular fractures were plated using resorbable plates and screws using Champy's principle. All the cases were evaluated clinically and radiologically for the type of fracture, need for the intermaxillary fixation (IMF) and its duration, duration of surgery, fixation at operation, state of reduction at operation, state of bone union after operation, anatomic reduction, paresthesia, occlusal discrepancies, soft tissue infection, immediate and late inflammatory reactions related to biodegradation process, and any need for the removal of the plates. Descriptives, Frequencies, and Chi-square test were used. In our study, the age group range was 5 to 55 years. Road traffic accidents accounted for the majority of patients six, (46.2%). Postoperative occlusal discrepancies were found in seven patients as mild to moderate, which resolved with IMF for 1-8 weeks. There were minimal complications seen and only as soft tissue infection. Use of biodegradable osteosynthesis system is a reliable alternative method for the fixation of zygomatic-complex and mandibular fractures. The biodegradable system still needs to be refined in material quality and handling to match the stability achieved with metal system. Biodegradable plates and screws is an ideal system for pediatric fractures with favorable outcome.

  1. Measures and limits of models of fixation selection.

    Directory of Open Access Journals (Sweden)

    Niklas Wilming

    Full Text Available Models of fixation selection are a central tool in the quest to understand how the human mind selects relevant information. Using this tool in the evaluation of competing claims often requires comparing different models' relative performance in predicting eye movements. However, studies use a wide variety of performance measures with markedly different properties, which makes a comparison difficult. We make three main contributions to this line of research: First we argue for a set of desirable properties, review commonly used measures, and conclude that no single measure unites all desirable properties. However the area under the ROC curve (a classification measure and the KL-divergence (a distance measure of probability distributions combine many desirable properties and allow a meaningful comparison of critical model performance. We give an analytical proof of the linearity of the ROC measure with respect to averaging over subjects and demonstrate an appropriate correction of entropy-based measures like KL-divergence for small sample sizes in the context of eye-tracking data. Second, we provide a lower bound and an upper bound of these measures, based on image-independent properties of fixation data and between subject consistency respectively. Based on these bounds it is possible to give a reference frame to judge the predictive power of a model of fixation selection. We provide open-source python code to compute the reference frame. Third, we show that the upper, between subject consistency bound holds only for models that predict averages of subject populations. Departing from this we show that incorporating subject-specific viewing behavior can generate predictions which surpass that upper bound. Taken together, these findings lay out the required information that allow a well-founded judgment of the quality of any model of fixation selection and should therefore be reported when a new model is introduced.

  2. Development of cermets for high-level radioactive waste fixation

    International Nuclear Information System (INIS)

    Aaron, W.S.; Quinby, T.C.; Kobisk, E.H.

    1979-01-01

    A method is currently under development for the solidification and fixation of commercial and defense high-level radioactive wastes in the form of ceramic particles encapsulated by metal, i.e., a cermet. The chemical and physical processing techniques which have been developed and the properties of the resulting cermet bodies are described in this paper. These cermets have the advantages of high thermal conductivity and low leach rates

  3. Salvage of infected total knee arthroplasty with Ilizarov external fixator

    Directory of Open Access Journals (Sweden)

    Venkata Gurava Reddy

    2011-01-01

    Full Text Available Background: Knee arthrodesis may be the only option of treatment in cases of chronic infected total knee arthroplasty (TKA with concomitant irreparable extensor mechanism disruption, extensive bone loss or severe systemic morbidities. Circular external fixation offers possible progressive adjustment to stimulate the bony fusion and to make corrections in alignment. We evaluated the results of knee arthrodesis with one or two stage circular external fixator for infected TKA. Materials and Methods: 16 cases of femoro-tibial fusion were retrospectively evaluated. Male-to-female ratio was 10:6. Mean age of the patients was 62.2 years. Cierney-Mader classification was used for anatomical and physiological evaluation while the bone stock deficiency was classified into mild, moderate and severe. Surgical technique involved either single or two stage arthrodesis using circular external fixator. Results: Union was achieved in 15 patients (93.75%. The mean duration for union (frame application time in these patients was 28.33 weeks (range 22 to 36 weeks. Analysis showed that in the group with frame application time of less than 28 weeks, the incidence of mild to moderate bone deficiency was 83.33%, while in the frame application time more than 28 weeks group the incidence was 20% (P-value 0.034. Similarly the incidence of Cierney-Mader 4B (Bl, Bs, Bls was found to be 33.33% in the group of frame application time of less than 28 weeks, while it was 90% in the group with frame application time more than 28 weeks (P-value 0.035. Conclusion: Circular external fixator is a safe and reliable method to achieve knee arthrodesis in cases of deep infection following TKA. Severe bone stock deficiency and Cierney- Mader type B host are likely risk factors for prolonged frame application time. We recommend a two-stage procedure especially when there is compromised host or severe bone loss.

  4. Complications associated with distraction plate fixation of wrist fractures.

    Science.gov (United States)

    Hanel, Douglas P; Ruhlman, Scott David; Katolik, Leo I; Allan, Christopher H

    2010-05-01

    This article discusses the major and minor complications of distal plating in the light of a cohort study carried out by the authors, who reviewed all patients undergoing bridge distraction plate fixation of distal radius fractures by three surgeons in a single level I trauma center. The article discusses the effectiveness and the complication rates associated with the technique. Copyright (c) 2010 Elsevier Inc. All rights reserved.

  5. Failure analysis of stainless steel femur fixation plate.

    Science.gov (United States)

    Hussain, P B; Mohammad, M

    2004-05-01

    Failure analysis was performed to investigate the failure of the femur fixation plate which was previously fixed on the femur of a girl. Radiography, metallography, fractography and mechanical testing were conducted in this study. The results show that the failure was due to the formation of notches on the femur plate. These notches act as stress raisers from where the cracks start to propagate. Finally fracture occurred on the femur plate and subsequently, the plate failed.

  6. Bacteria on External Fixators: Which Prep is Best?

    Science.gov (United States)

    2012-01-01

    aureus (lux). After 12 hours in the broth, a sufficient time to allow biofilm formation ,11 the constructs were individually removed and baseline imaging...difference when cleansing components consisting of stainless steel and alumi- num.15–17 We also found that a simulated external fixator adjustment exposed...Albert E, et al. Direct continuous method for monitoring biofilm infection in a mouse model. Infect Immun. 2003;71: 882–890. 11. Charles CA, Ricotti CA

  7. Early Experience with Biodegradable Fixation of Pediatric Mandibular Fractures.

    Science.gov (United States)

    Mazeed, Ahmed Salah; Shoeib, Mohammed Abdel-Raheem; Saied, Samia Mohammed Ahmed; Elsherbiny, Ahmed

    2015-09-01

    This clinical study aims to evaluate the stability and efficiency of biodegradable self-reinforced poly-l/dl-lactide (SR-PLDLA) plates and screws for fixation of pediatric mandibular fractures. The study included 12 patients (3-12 years old) with 14 mandibular fractures. They were treated by open reduction and internal fixation by SR-PLDLA plates and screws. Maxillomandibular fixation was maintained for 1 week postoperatively. Clinical follow-up was performed at 1 week, 6 weeks, 3 months, and 12 months postoperatively. Radiographs were done at 1 week, 3 months, and 12 months postoperatively to observe any displacement and fracture healing. All fractures healed both clinically and radiologically. No serious complications were reported in the patients. Normal occlusion was achieved in all cases. Biodegradable osteofixation of mandibular fractures offers a valuable clinical solution for pediatric patients getting the benefit of avoiding secondary surgery to remove plates, decreasing the hospital stay, further painful procedures, and psychological impact.

  8. Sorption and fixation of large cations by shale formations

    International Nuclear Information System (INIS)

    Brindley, G.W.

    1977-01-01

    Large cations such as Cs + are preferentially sorbed and partially fixed by fine-grained 2 : 1 type layer silicates such as micas, vermiculites, smectites and various mixed-layer minerals. Since these minerals are common constituents of many shale formations, these formations may provide suitable location for the burial of radioactive waste containers. However, the usual investigations of cation sorption and fixation must be extended to the conditions likely to develop in the vicinity of buried radioactive waste. Prior to possible leakage from buried containers, elevated temperatures around the burial site will develop leading to hydrothermal modification of the surrounding mineralogy. A range of temperature and of mineralogy must be envisaged. If and when leakage occurs, an outward diffusion of radioactive ions will occur by solvation in the fluids in the shale. The ratio of radioactive ions/normal ions will diminish outwards from the source. At near distances from the source high temperature modifications of the clay minerals and high concentrations of radioactive cations may lead to saturation of the fixation capacity. At greater distances, little or no thermal modification of the clay minerals and lower concentrations of ions will permit maximum sorption and fixation

  9. New fixation method for maxillary distraction osteogenesis using locking attachments.

    Science.gov (United States)

    Suzuki, Eduardo Yugo; Buranastidporn, Boonsiva; Ishii, Masatoshi

    2006-10-01

    The external traction hooks of the intraoral splint used in the rigid external distraction (RED) system for maxillary distraction osteogenesis interfere with the surgical procedures. The purpose of this study is to introduce an innovative splint fixation method for maxillary distraction osteogenesis with Locking Attachments and evaluate their advantages, such as reduction of operating time compared with the traditional intraoral splint method. Retrospective comparison of operative times of maxillary Le Fort I osteotomy procedures was carried out with the traditional protocol using the intraoral splint cemented to the maxillary dentition (n = 14), and a removable intraoral splint that is inserted postsurgically (n = 14). Operative procedure times were compared and analyzed statistically using the data extracted from the surgical records. There were no complications inserting the removable splint postsurgically, including pain, discomfort, or time-consuming procedure. Stable and secure splint fixation was obtained before the distraction procedure and the desired treatment goals were obtained in all patients. The total operative procedure times were significantly reduced in the Locking Attachments group by 24% to 41% (approximately 65 minutes) compared with earlier operations involving the conventional splints (P Maxillary distraction osteogenesis with the Locking Attachments is a highly effective fixation approach to manage severe hypoplastic maxilla, eliminating lip constraints resulting from scarring and allowing for easier, more deliberate and careful dissection. The use of the Locking Attachments is reliable in craniofacial surgery and has proved to be advantageous in the reduction of the operating time and surgical risks.

  10. Stress Fractures of Tibia Treated with Ilizarov External Fixator.

    Science.gov (United States)

    Górski, Radosław; Żarek, Sławomir; Modzelewski, Piotr; Górski, Ryszard; Małdyk, Paweł

    2016-08-30

    Stress fractures are the result of cyclic loading of the bone, which gradually becomes damaged. Most often they are treated by rest or plaster cast and, in rare cases, by internal fixation. There is little published data on initial reposition followed by stabilization with the Ilizarov apparatus in such fractures. Six patients were treated with an external fixator according to the Ilizarov method for a stress fracture of the tibia between 2007 and 2015. Three patients were initially treated conservatively. Due to increasing tibial deformation, they were qualified for surgical treatment with external stabilization. In the other patients, surgery was the first-line treatment. All patients demonstrated risk factors for a stress fracture. After the surgery, they fully loaded the operated limb. No patient developed malunion, nonunion, infection or venous thrombosis. The average time from the first operation to the removal of the external fixator was 19 weeks. Radiographic and clinical outcomes were satisfactory in all patients. 1. The Ilizarov method allows for successful stabilization of stress fractures of the tibia. 2. It may be a good alternative to internal stabilization, especially in patients with multiple comorbidities which affect bone quality and may impair soft tissue healing.

  11. Rib fractures in trauma patients: does operative fixation improve outcome?

    Science.gov (United States)

    Majak, Peter; Næss, Pål A

    2016-12-01

    Renewed interest in surgical fixation of rib fractures has emerged. However, conservative treatment is still preferred at most surgical departments. We wanted to evaluate whether operative treatment of rib fractures may benefit severely injured patients. Several studies report a reduction in mechanical ventilation time, ICU length of stay (LOS), hospital LOS, pneumonia, need for tracheostomy, pain and costs in operatively treated patients with multiple rib fractures compared with patients treated nonoperatively. Although patient selection and timing of the operation seem crucial for successful outcome, no consensus exists. Mortality reduction has only been shown in a few studies. Most studies are retrospective cohort and case-control studies. Only four randomized control trials exist. Conservative treatment, consisting of respiratory assistance and pain control, is still the treatment of choice in the vast majority of patients with multiple rib fractures. In selected patients, operative fixation of fractured ribs within 72 h postinjury may lead to better outcome. More randomized control trials are needed to further determine who benefits from surgical fixation of rib fractures.

  12. Nitrogen fixation in four dryland tree species in central Chile

    International Nuclear Information System (INIS)

    Ovalle, C.; Arredondo, S.; Aronson, J.; Longeri, L.; Avendano, J.

    1998-01-01

    Results are presented from a 5-year experiment using 15 N-enriched fertilizer to determine N 2 fixation in four tree species on degraded soils in a Mediterranean-climate region of central Chile in which there are 5 months of drought. Species tested included three slow-growing but long-lived savannah trees native to southers South America, (acacia caven, Prosopic alba and P. chilensis; Mimosoideae), and Tagasaste (Chamaecytisus proliferus ssp. palmensis; Papilonoideae), a fast-growing but medium-lived tree from the Canary Islands. Tagasaste produced four- to twenty-fold more biomass than the other species, but showed declining N 2 fixation and biomass accumulation during the 5th year, corresponding to the juvenile-to-adult developmental transition. Nitrogen content was significantly higher in Tagasaste and Acacia caven than in the other species. The data revealed inter-specific differences in resource allocation and phenology of N 2 fixation rarely detailed for woody plants in dryland regions. (author)

  13. Treatment Approach for Infection of Healed Fractures After Internal Fixation.

    Science.gov (United States)

    Lawrenz, Joshua M; Frangiamore, Salvatore J; Rane, Ajinkya A; Cantrell, William Alex; Vallier, Heather A

    2017-11-01

    To review the efficacy of a treatment approach for patients with infection and colonized implants after open reduction and internal fixation of fractures. Retrospective case series. Level one trauma center. Twenty patients were treated for wound infection with colonized implants after open reduction and internal fixation. Surgical debridement, removal of implants, and a short postoperative oral antibiotic course. The course of patients after surgical debridement and removal of implants, including culture results, antibiotic administration, and presence of recurrent clinical infection and radiographic union. Twenty patients had clinical presentations, including skin breakdown, serous drainage, purulent drainage and/or exposed implants, most commonly of the tibia (15 of 20). Mean time from index procedure to debridement with implant removal was 19.7 months. At the time of debridement and implant removal, 18 of 20 (90%) patients had a positive intraoperative culture (16 routine cultures and 2 broth cultures). The most common bacteria were Enterobacter cloacae (5/17) and methicillin-sensitive Staphylococcus aureus (4/17). All patients had soft tissue healing without signs of recurrent infection after mean follow up of 40 months after implant removal. Surgical debridement with implant removal plus a short oral antibiotic course is effective to resolve wound infection with a colonized implant in the setting of healed fracture after internal fixation. Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

  14. Awake craniotomy using electromagnetic navigation technology without rigid pin fixation.

    Science.gov (United States)

    Morsy, Ahmed A; Ng, Wai Hoe

    2015-11-01

    We report our institutional experience using an electromagnetic navigation system, without rigid head fixation, for awake craniotomy patients. The StealthStation® S7 AxiEM™ navigation system (Medtronic, Inc.) was used for this technique. Detailed preoperative clinical and neuropsychological evaluations, patient education and contrast-enhanced MRI (thickness 1.5mm) were performed for each patient. The AxiEM Mobile Emitter was typically placed in a holder, which was mounted to the operating room table, and a non-invasive patient tracker was used as the patient reference device. A monitored conscious sedation technique was used in all awake craniotomy patients, and the AxiEM Navigation Pointer was used for navigation during the procedure. This offers the same accuracy as optical navigation, but without head pin fixation or interference with intraoperative neurophysiological techniques and surgical instruments. The application of the electromagnetic neuronavigation technology without rigid head fixation during an awake craniotomy is accurate, and offers superior patient comfort. It is recommended as an effective adjunctive technique for the conduct of awake surgery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Tissue fixation and autoradiographic negative chemography in rat oral epithelium

    Energy Technology Data Exchange (ETDEWEB)

    Prime, S.S.; MacDonald, D.G. (Glasgow Dental Hospital (UK))

    1983-01-01

    The effect of routine methods of tissue fixation on autoradiographic negative chemography was investigated in adult rat palatal and tongue epithelia following the incorporation of /sup 3/H thymidine in vivo. Tissues fixed in formalin or Bouin's without acetic acid demonstrated more negative chemography than those fixed in Bouin's fluid, formol-acetic-methanol or Carnoy's solutions. These findings were associated with the lowest silver grain counts per nucleus in the formalin fixed tissues, low grain counts in tissues fixed in Bouin's without acetic acid, but the addition of acetic acid to make complete Bouin's fluid gave results similar to those following fixation with Carnoy's solution. The highest silver grain counts were obtained with tissues fixed in formol-acetic-methanol. The relationship between negative chemography and the labelling indices of tissues was unclear except where the negative chemographic effects were severe. Formalin fixed tissues showed the maximum negative chemographic effects and the lowest labelling indices. Carnoy's solution appeared to be the fixative of choice for cell kinetic studies of oral epithelium.

  16. Liquifying PLDLLA Anchor Fixation in Achilles Reconstruction for Insertional Tendinopathy.

    Science.gov (United States)

    Boden, Stephanie A; Boden, Allison L; Mignemi, Danielle; Bariteau, Jason T

    2018-04-01

    Insertional Achilles tendinopathy (IAT) is a frequent cause of posterior heel pain and is often associated with Haglund's deformity. Surgical correction for refractory cases of IAT has been well studied; however, the method of tendon fixation to bone in these procedures remains controversial, and to date, no standard technique has been identified for tendon fixation in these surgeries. Often, after Haglund's resection, there is large exposed cancellous surface for Achilles reattachment, which may require unique fixation to optimize outcomes. Previous studies have consistently demonstrated improved patient outcomes after Achilles tendon reconstruction with early rehabilitation with protected weight bearing, evidencing the need for a strong and stable anchoring of the Achilles tendon that allows early weight bearing without tendon morbidity. In this report, we highlight the design, biomechanics, and surgical technique of Achilles tendon reconstruction with Haglund's deformity using a novel technique that utilizes ultrasonic energy to liquefy the suture anchor, allowing it to incorporate into surrounding bone. Biomechanical studies have demonstrated superior strength of the suture anchor utilizing this novel technique as compared with prior techniques. However, future research is needed to ensure that outcomes of this technique are favorable when compared with outcomes using traditional suture anchoring methods. Level V: Operative technique.

  17. Transcriptional Profiling of Nitrogen Fixation in Azotobacter vinelandii▿†

    Science.gov (United States)

    Hamilton, Trinity L.; Ludwig, Marcus; Dixon, Ray; Boyd, Eric S.; Dos Santos, Patricia C.; Setubal, João C.; Bryant, Donald A.; Dean, Dennis R.; Peters, John W.

    2011-01-01

    Most biological nitrogen (N2) fixation results from the activity of a molybdenum-dependent nitrogenase, a complex iron-sulfur enzyme found associated with a diversity of bacteria and some methanogenic archaea. Azotobacter vinelandii, an obligate aerobe, fixes nitrogen via the oxygen-sensitive Mo nitrogenase but is also able to fix nitrogen through the activities of genetically distinct alternative forms of nitrogenase designated the Vnf and Anf systems when Mo is limiting. The Vnf system appears to replace Mo with V, and the Anf system is thought to contain Fe as the only transition metal within the respective active site metallocofactors. Prior genetic analyses suggest that a number of nif-encoded components are involved in the Vnf and Anf systems. Genome-wide transcription profiling of A. vinelandiicultured under nitrogen-fixing conditions under various metal amendments (e.g., Mo or V) revealed the discrete complement of genes associated with each nitrogenase system and the extent of cross talk between the systems. In addition, changes in transcript levels of genes not directly involved in N2fixation provided insight into the integration of central metabolic processes and the oxygen-sensitive process of N2fixation in this obligate aerobe. The results underscored significant differences between Mo-dependent and Mo-independent diazotrophic growth that highlight the significant advantages of diazotrophic growth in the presence of Mo. PMID:21724999

  18. Photosynthate partitioning and nitrogen fixation of alfalfa and birdsfoot trefoil

    International Nuclear Information System (INIS)

    Shieh, W.J.

    1985-01-01

    Nodule mass and number are usually correlated with rates of nitrogen fixation in legumes. Birdsfoot trefoil (Lotus corniculatus L.) with more than twice the nodule number and mass, however, fixes far less nitrogen than alfalfa (Medicago sativa L.) at the same age. In this research, photosynthesis and photosynthate partitioning and utilization in relation to nitrogen fixation of alfalfa and birdsfoot trefoil were examined in order to determine their relationship to nitrogen fixation potential. Photosynthate to nodules was studied using 14 CO 2 labeling techniques. Partitioning patterns were altered by shading and dark depletion treatments. Efficiency of photosynthate utilization was examined by determining turnover of 14 C photosynthate in nodule metabolites and by studying rates of cyanide-resistant and cyanide-sensitive O 2 uptake. Alfalfa nodule activity was greater than trefoil expressed on a hole pot or nodule dry weight basis. Both shading and dark treatments significantly reduced nodule activity as estimated by the acetylene reduction assay. Shoots of both species were found to be the dominant sinks for photosynthate. Percentage 14 C recovered in alfalfa roots was more than twice that of trefoil at 1,2,3,4 and 24 h after labeling. Greater relative specific radioactivity (RSA) in nodules of both species suggests that they were stronger sinks for current photosynthate than roots

  19. Fixation probability in a two-locus intersexual selection model.

    Science.gov (United States)

    Durand, Guillermo; Lessard, Sabin

    2016-06-01

    We study a two-locus model of intersexual selection in a finite haploid population reproducing according to a discrete-time Moran model with a trait locus expressed in males and a preference locus expressed in females. We show that the probability of ultimate fixation of a single mutant allele for a male ornament introduced at random at the trait locus given any initial frequency state at the preference locus is increased by weak intersexual selection and recombination, weak or strong. Moreover, this probability exceeds the initial frequency of the mutant allele even in the case of a costly male ornament if intersexual selection is not too weak. On the other hand, the probability of ultimate fixation of a single mutant allele for a female preference towards a male ornament introduced at random at the preference locus is increased by weak intersexual selection and weak recombination if the female preference is not costly, and is strong enough in the case of a costly male ornament. The analysis relies on an extension of the ancestral recombination-selection graph for samples of haplotypes to take into account events of intersexual selection, while the symbolic calculation of the fixation probabilities is made possible in a reasonable time by an optimizing algorithm. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Tissue fixation and autoradiographic negative chemography in rat oral epithelium

    International Nuclear Information System (INIS)

    Prime, S.S.; MacDonald, D.G.

    1983-01-01

    The effect of routine methods of tissue fixation on autoradiographic negative chemography was investigated in adult rat palatal and tongue epithelia following the incorporation of 3 H thymidine in vivo. Tissues fixed in formalin or Bouin's without acetic acid demonstrated more negative chemography than those fixed in Bouin's fluid, formol-acetic-methanol or Carnoy's solutions. These findings were associated with the lowest silver grain counts per nucleus in the formalin fixed tissues, low grain counts in tissues fixed in Bouin's without acetic acid, but the addition of acetic acid to make complete Bouin's fluid gave results similar to those following fixation with Carnoy's solution. The highest silver grain counts were obtained with tissues fixed in formol-acetic-methanol. The relationship between negative chemography and the labelling indices of tissues was unclear except where the negative chemographic effects were severe. Formalin fixed tissues showed the maximum negative chemographic effects and the lowest labelling indices. Carnoy's solution appeared to be the fixative of choice for cell kinetic studies of oral epithelium. (author)