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Sample records for monomethyl ether ame

  1. Evaluation of workers exposed to ethylene glycol monomethyl ether and ethylene glycol monomethyl ether acetate.

    Science.gov (United States)

    Park, Jiyoung; Yoon, Chungsik; Byun, Hyaejeong; Kim, Yangho; Park, Donguk; Ha, Kwonchul; Lee, Sang man; Park, Sungki; Chung, Eunkyo

    2012-01-01

    Ethylene glycol monomethyl ether (EGME) and ethylene glycol monomethyl ether acetate (EGMEA) are widely used in industries as solvents for coatings, paint and ink, but exposure data are limited because they are minor components out of mixed solvents, as well as because of inconsistency in desorption solvent use. The objective of this study was to investigate the worker exposure profile of EGME and EGMEA. Our study investigated 27 workplaces from June to September 2008 and detected EGME and EGMEA in 20 and 13, respectively. Both personal and area sampling were conducted using a charcoal tube to collect EGME and EGMEA. Gas chromatography with a flame ionization detector was used to analyze these compounds after desorption using a mixture of methylene chloride and methanol. The arithmetic mean concentrations of EGME and EGMEA during periods of full work shifts were 2.59 ppm and 0.33 ppm, respectively. The exposure levels were lower than the Korean Ministry of Labor (MOL) OEL (5 ppm) but higher than the ACGIH TLV (0.1 ppm). In general, the working environments were poor and required much improvement, including the use of personal protective equipment. Only 50% of the workplaces had local exhaust ventilation systems in operation. The average capture velocity of the operating local exhaust ventilation systems was 0.27 m/s, which did not meet the legal requirement of 0.5 m/s. Educating workers to clearly understand the handling and use of hazardous chemicals and improving working conditions are strongly suggested.

  2. Mechanism of Alternariol monomethyl ether-induced mitochondrial apoptosis in human colon carcinoma cells.

    Science.gov (United States)

    Bensassi, Fatma; Gallerne, Cindy; el Dein, Ossama Sharaf; Hajlaoui, Mohamed Rabeh; Bacha, Hassen; Lemaire, Christophe

    2011-12-18

    Alternariol monomethyl ether (AME) is a major mycotoxin produced by fungi of the genus Alternaria and a common contaminant of food products such as fruits and cereals worldwide. AME can cause serious health problems for animals as well as for humans. In this study, human colon carcinoma cells (HCT116) were used to explore the mechanisms of cell death induced by AME. Exposure of HCT116 cells to AME resulted in significant cytotoxicity manifested by a loss in cell viability mainly mediated by activation of apoptotic process. AME activated the mitochondrial apoptotic pathway evidenced by the opening of the mitochondrial permeability transition pore (PTP), loss of the mitochondrial transmembrane potential (ΔΨm) downstream generation of O(2)(-), cytochrome c release and caspase 9 and 3 activation. Experiments conducted on isolated organelles indicated that AME does not directly target mitochondria to induce PTP-dependent permeabilization of mitochondrial membranes. Moreover, no difference was observed in Bax-KO cells in comparison to parental cells, suggesting that the pro-apoptotic protein Bax is not involved in AME-induced mitochondrial apoptosis. Our findings demonstrate for the first time that AME induces cell death in human colon carcinoma cells by activating the mitochondrial pathway of apoptosis.

  3. 76 FR 69659 - Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether Methacrylate Graft...

    Science.gov (United States)

    2011-11-09

    ... AGENCY 40 CFR Part 180 Methacrylic Acid-Methyl Methacrylate-Polyethylene Glycol Monomethyl Ether... residues of methacrylic acid-methyl methacrylate- polyethylene glycol monomethyl ether methacrylate graft... permissible level for residues of methacrylic acid-methyl methacrylate-polyethylene glycol monomethyl...

  4. Mycoflora and occurrence of alternariol and alternariol monomethyl ether in Brazilian sunflower from sowing to harvest.

    Science.gov (United States)

    Pozzi, Claudia R; Braghini, Raquel; Arcaro, Juliana R P; Zorzete, Patricia; Israel, Ana Lia M; Pozar, Ivani Otsuk; Denucci, Silmar; Corrêa, Benedito

    2005-07-13

    The present study aimed to analyze the mycoflora and the occurrence of alternariol (AOH) and alternariol monomethyl ether (AME) in grain samples of sunflower during different stages of plant development in Nova Odessa, State of São Paulo, Brazil. The data obtained were correlated with the presence of fungi in soil, wind-dispersed fungi, and the predominant climatic conditions of the region where the experiment was carried out. Analysis of the mycoflora revealed the presence of Fusarium verticillioides and Alternaria alternata in 70% and 46% of the samples, respectively. The profile of wind-dispersed fungi also showed F. verticillioides as the most frequently isolated fungus (68%), although A. alternata was detected in 28% of samples. In soil, Penicillium was the most frequent species (49.9%), followed by F. verticillioides (47.7%) and A. alternata (10.9%). Regarding water activity, sunflower grains presenting a high frequency of isolation of F. verticillioides and A. alternatahad a water activity ranging from 0.92 to 0.96, and statistical analysis revealed a negative linear correlation between the isolation of fungi and water activity. HPLC analysis showed that 18% of the sunflower grains were contaminated with alternariol (24.9-170.9 ng/g) and 10% with alternariol monomethyl ether (14.1-108.6 ng/g). The contamination of sunflower grains with AOH and AME in the field was low when compared to the LD50 necessary to cause toxicity to animals. However, the contamination with other toxigenic fungi such as F. verticillioides may indicate the presence of other mycotoxins in sunflower grains and a possible synergistic effect between them. This is the first report of the natural occurrence of alternariol and alternariol monomethyl ether in sunflower grains in Brazil.

  5. Natural occurrence of alternariol and alternariol monomethyl ether in soya beans.

    Science.gov (United States)

    Oviedo, M S; Barros, G G; Chulze, S N; Ramirez, M L

    2012-08-01

    The natural occurrence of alternariol (AOH) and alternariol monomethyl ether (AME) in soya beans harvested in Argentina was evaluated. Both toxins were simultaneously detected by using HPLC analysis coupled with a solid phase extraction column clean-up. Characteristics of this in-house method such as accuracy, precision and detection and quantification limits were defined by means of recovery test with spiked soya bean samples. Out of 50 soya bean samples, 60% showed contamination with the mycotoxins analyzed; among them, 16% were only contaminated with AOH and 14% just with AME. Fifteen of the positive samples showed co-occurrence of both mycotoxins analyzed. AOH was detected in concentrations ranging from 25 to 211 ng/g, whereas AME was found in concentrations ranging from 62 to 1,153 ng/g. Although a limited number of samples were evaluated, this is the first report on the natural occurrence of Alternaria toxins in soya beans and is relevant from the point of view of animal public health.

  6. Degradation of the Alternaria mycotoxins alternariol, alternariol monomethyl ether, and altenuene upon bread baking.

    Science.gov (United States)

    Siegel, David; Feist, Michael; Proske, Matthias; Koch, Matthias; Nehls, Irene

    2010-09-01

    The stability of the Alternaria mycotoxins alternariol, alternariol monomethyl ether, and altenuene upon bread baking was investigated by model experiments using a spiked wholemeal wheat flour matrix. For alternariol and alternariol monomethyl ether, but not for altenuene, degradation products, formed through a sequence of hydrolysis and decarboxylation, could be identified in pilot studies. The simultaneous quantification of alternariol, alternariol monomethyl ether, altenuene, and the degradation products was achieved by a newly developed high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) multimethod. The obtained quantitative data indicate that the Alternaria mycotoxins are barely degraded during wet baking, while significant degradation occurs upon dry baking, with the stability decreasing in the order alternariol monomethyl ether>alternariol>altenuene. The novel degradation products could be detected after the wet baking of flour spiked with alternariol and in a sample survey of 24 commercial cereal based baking products.

  7. Preliminary report of clinical application of hematoporphyrin monomethyl ether in photodynamic therapy for alimentary cancers

    Science.gov (United States)

    Gu, Ying; Li, Junheng; Xu, De-Yu; Zhang, Zi-Qi; Huang, Yingcai; Wang, Kai

    1995-03-01

    A new sensitizer, hematoporphyrin monomethyl ether (HMME), purified by the Second Military Medical University was used with a gold vapor laser for PDT in 8 cases of alimentary cancers. The results showed that 2 cases of early stage gastric cancer and 1 case of rectal polyps with malignancy revealed CR, SR was obtained in 1 case of esophageal cancer and 4 others were MR. No sunburn occurred within the 8 patients who received 12 doses of HMME at 5 mg/kg 2 - 3 hours prior to laser treatment and who were kept away from sun light only 6 hours. Hematoporphyrin monomethyl ether is an effective single compound and safer for PDT.

  8. Ethylene glycol monomethyl ether (EGME) and propylene glycol monomethyl ether (PGME): inhalation fertility and teratogenicity studies in rats, mice and rabbits.

    Science.gov (United States)

    Hanley, T R; Young, J T; John, J A; Rao, K S

    1984-08-01

    A combined dominant lethal-fertility study was conducted in which male and female Sprague-Dawley (CD) rats were exposed to 0, 30, 100 or 300 ppm of ethylene glycol monomethyl ether (EGME) vapor for 6 hr/day, 5 days/week for 13 weeks and then mated to untreated counterparts. Among males, fertility was completely suppressed after exposure to 300 ppm. A partial restoration of reproductive function was evident following 13 weeks of recovery. No treatment-related reproductive effects were observed among males exposed subchronically to 100 ppm, or among females exposed to 300 ppm or below of EGME. Studies to assess the effects of inhaled EGME on embryonal and fetal development were also conducted in Fischer 344 rats, CF-1 mice, and New Zealand White rabbits. Rats and rabbits were exposed to concentrations of 0, 3, 10 or 50 ppm for 6 hr/day on days 6-15 or 6-18 of gestation, respectively. Exposure of rabbits to 50 ppm resulted in significant teratologic effects, an increased resorption rate, and decreased fetal body weight. Slight fetotoxicity in the form of skeletal variations were observed among rats exposed to 50 ppm. Exposure of pregnant mice to 0, 10, or 50 ppm for 6 hr/day on days 6-15 of gestation resulted in slight fetotoxicity at 50 ppm. No significant treatment-related effects were observed at 10 ppm of EGME or below in any of the species tested. Separate groups of pregnant rats and rabbits were exposed to 0, 500, 1500 or 3000 ppm of propylene glycol monomethyl ether (PGME) during organogenesis.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Ethylene glycol monomethyl ether (EGME) and propylene glycol monomethyl ether (PGME): inhalation fertility and teratogenicity studies in rats, mice and rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Hanley, T.R. Jr.; Young, J.T.; John, J.A.; Rao, K.S.

    1984-08-01

    A combined dominant lethal-fertility study was conducted in which male and female Sprague-Dawley (CD) rats were exposed to 0, 30, 100, or 300 ppm of ethylene glycol monomethyl ether (EGME) vapor for 6 hr/day, 5 days/week for 13 weeks and then mated to untreated counterparts. Among males, fertility was completely suppressed after exposure to 300 ppm. A partial restoration of reproductive function was evident following 13 weeks of recovery. No treatment-related reproductive effects were observed among males exposed subchronically to 100 ppm, or among females exposed to 300 ppm or below of EGME. Studies to assess the effects of inhaled EGME on embryonal and fetal development were also conducted in Fischer 344 rats. CF-1 mice, and New Zealand White rabbits. Rats and rabbits were exposed to concentrations of 0, 3, 10, or 50 ppm for 6 hr/day on days 6-15 or 6-18 of gestation, respectively. Exposure of rabbits to 50 ppm resulted in significant teratologic effects, an increased resorption rate, and decreased fetal body weight. Slight fetotoxicity in the form of skeletal variations were observed among rats exposed to 50 ppm. Separate groups of pregnant rats and rabbits were exposed to 0, 500, 1500, or 3000 ppm of propylene glycol monomethyl ether (PGME) during organogenesis. Mild CNS depression was observed among rats and rabbits exposed to 3000 ppm of PGME. Fetal examination revealed no embryotoxic or teratogenic effects among either species. Thus, it was concluded that PGME was not teratogenic at exposure levels up to 3000 ppm.

  10. Rapeseed Oil Monoester of Ethylene Glycol Monomethyl Ether as a New Biodiesel

    Directory of Open Access Journals (Sweden)

    Jiang Dayong

    2011-01-01

    Full Text Available A novel biodiesel named rapeseed oil monoester of ethylene glycol monomethyl ether is developed. This fuel has one more ester group than the traditional biodiesel. The fuel was synthesized and structurally identified through FT-IR and P1PH NMR analyses. Engine test results show that when a tested diesel engine is fueled with this biodiesel in place of 0# diesel fuel, engine-out smoke emissions can be decreased by 25.0%–75.0%, CO emissions can be reduced by 50.0%, and unburned HC emissions are lessened significantly. However, NOx emissions generally do not change noticeably. In the area of combustion performance, both engine in-cylinder pressure and its changing rate with crankshaft angle are increased to some extent. Rapeseed oil monoester of ethylene glycol monomethyl ether has a much higher cetane number and shorter ignition delay, leading to autoignition 1.1°CA earlier than diesel fuel during engine operation. Because of certain amount of oxygen contained in the new biodiesel, the engine thermal efficiency is improved 13.5%–20.4% when fueled with the biodiesel compared with diesel fuel.

  11. Preparation of diethylene glycol monomethyl ether monolaurate catalyzed by active carbon supported KF/CaO.

    Science.gov (United States)

    Lou, Shengfeng; Jia, Lihua; Guo, Xiangfeng; Wu, Ping; Gao, Lianbing; Wang, Jianjun

    2015-01-01

    Diethylene glycol monomethyl ether monolaurate (DGMEML) was synthesized via the reaction of diethylene glycol monomethyl ether (DGME) with methyl laurate (ML) by a new solid base catalyst of KF/CaO/AC, which was prepared by impregnation method using active carbon as carrier. The catalysts were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), nitrogen physisorption-desorption and Hammett indicator methods; the effect of the mole ratio of KF to CaO, DGME to ML molar ratio, amount of catalyst, reaction time and temperature on the yield of DGMEML were studied; and the relationship between the structure of the catalyst and the yield of DGMEML was investigated. The formed KCaF3 and K2O were acting as the main active components in the catalytic transesterification; the highest yield of 96.3 % was obtained as KF-to-CaO molar ratio of 2.0, DGME to ML molar ratio of 4.0, catalyst amount of 5 wt%, and reaction time of 30 min at 75 °C; and the catalyst displayed good stability in the transesterification.

  12. Conjugation of the mycotoxins alternariol and alternariol monomethyl ether in tobacco suspension cells.

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    Hildebrand, Andreas A; Kohn, Beate N; Pfeiffer, Erika; Wefers, Daniel; Metzler, Manfred; Bunzel, Mirko

    2015-05-20

    The mycotoxins alternariol (AOH) and alternariol-9-O-methyl ether (AME) carry three and two phenolic hydroxyl groups, respectively, which makes them candidates for the formation of conjugated metabolites in plants. Such conjugates may escape routine methods of analysis and have therefore been termed masked or, more recently, modified mycotoxins. We report now that AOH and AME are extensively conjugated in suspension cultures of tobacco BY-2 cells. Five conjugates of AOH were identified by MS and NMR spectroscopy as β-D-glucopyranosides (attached in AOH 3- or 9-position) as well as their 6'-malonyl derivatives, and as a gentiobiose conjugate. For AME, conjugation resulted in the d-glucopyranoside (mostly attached in the AME 3-position) and its 6'- and 4'-malonyl derivatives. Pronounced differences were noted for the quantitative pattern of AOH and AME conjugates as well as for their phytotoxicity. Our in vitro study demonstrates for the first time that masked mycotoxins of AOH and AME can be formed in plant cells.

  13. Precise determination of the Alternaria mycotoxins alternariol and alternariol monomethyl ether in cereal, fruit and vegetable products using stable isotope dilution assays.

    Science.gov (United States)

    Asam, Stefan; Konitzer, Katharina; Rychlik, Michael

    2011-02-01

    Cereal, fruit and vegetable products were analyzed for contamination with the Alternaria mycotoxins alternariol (AOH) and alternariol monomethyl ether (AME) using stable isotope dilution assays (SIDAs). Both toxins were practically not detected in cereals and cereal products: AOH-one out of 13 samples at a content of 4.1 μg/kg; AME-two out of 13 samples at contents ranging between 0.2 and 0.6 μg/kg. However, if cereals for animal nutrition were analyzed, much higher values were found: AOH-five out of six samples (13-250 μg/kg); AME-six out of six samples (3-100 μg/kg). This finding may pose a potential problem concerning animal health. AOH and AME were frequently detected in vegetable products: AOH-5 out of 10 samples (2.6-25 μg/kg); AME-6 out of 10 samples (0.1-5 μg/kg). Tomato products were affected, especially. The highest content of AOH (25 μg/kg) and AME (5 μg/kg) were found in triple concentrated tomato paste. Special wines like "Trockenbeerenauslese" or "Spätlese" (affected by noble rot in the vineyard) contained AOH (4/6 samples; 1.2-4.9 μg/kg) and AME (4/6 samples; 0.1-0.3 μg/kg), but the values did not exceed the values of both toxins that were found generally in wines.

  14. Short and stereoselective total synthesis of furano lignans (+/-)-dihydrosesamin, (+/-)-lariciresinol dimethyl ether, (+/-)-acuminatin methyl ether, (+/-)-sanshodiol methyl ether, (+/-)-lariciresinol, (+/-)-acuminatin, and (+/-)-lariciresinol monomethyl ether and furofuran lignans (+/-)-sesamin, (+/-)-eudesmin, (+/-)-piperitol methyl ether, (+/-)-pinoresinol, (+/-)-piperitol, and (+/-)-pinoresinol monomethyl ether by radical cyclization of epoxides using a transition-metal radical source.

    Science.gov (United States)

    Roy, Subhas Chandra; Rana, Kalyan Kumar; Guin, Chandrani

    2002-05-17

    Intramolecular radical cyclization of suitably substituted epoxy ethers 4a-g using bis(cyclopentadienyl)titanium(III) chloride as the radical source resulted in trisubstituted tetrahydrofurano lignans and 2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane lignans depending on the reaction conditions. The titanium(III) species was prepared in situ from commercially available titanocene dichloride and activated zinc dust in THF. Upon radical cyclization followed by acidic workup, epoxy olefinic ethers 4a-g afforded furano lignans dihydrosesamin 1a, lariciresinol dimethyl ether 1b, acuminatin methyl ether 1e, and sanshodiol methyl ether 1g directly and lariciresinol 1h, acuminatin 1i, and lariciresinol monomethyl ether 1j after removal of the benzyl protecting group by controlled hydrogenolysis of the corresponding cyclized products. The furofuran lignans sesamin 2a, eudesmin 2b, and piperitol methyl ether 2e were also prepared directly by using the same precursors 4a-f on radical cyclization followed by treatment with iodine and pinoresinol 2h, piperitol 2i, and pinoresinol monomethyl ether 2j after controlled hydrogenolysis of the benzyl protecting group of the corresponding cyclized products. Two naturally occurring acyclic lignans, secoisolariciresinol 5h and secoisolariciresinol dimethyl ether 5b, have also been prepared by exhaustive hydrogenolysis of 2h and 2b, respectively.

  15. Evaluation of Triethylene Glycol Monomethyl Ether (TRIEGME) as an Alternative Fuel System Icing Inhibitor for JP-8 Fuel

    Science.gov (United States)

    2010-08-01

    could be explained by a non-uniform condensation on the surface of the panel due to non-uniform surface temperatures created by inadequate contact...RXS 10-090 7 RECOMMENDATION Careful engineering review and risk analyses must be performed by weapon systems managers considering switching...heart following prenatal exposure to ethylene glycol monomethyl ether. Drug Chem. Toxicol. 9:1-14. 29. Hoflack, JC; et aI., 1995, Mutat Res, 341(4

  16. Differential morphological effects in rat corpora lutea among ethylene glycol monomethyl ether, atrazine, and bromocriptine.

    Science.gov (United States)

    Taketa, Yoshikazu; Inoue, Kaoru; Takahashi, Miwa; Yamate, Jyoji; Yoshida, Midori

    2013-07-01

    Ethylene glycol monomethyl ether (EGME) or atrazine induces luteal cell hypertrophy in rats. Our previous study suggested that EGME stimulates both new and old corpora lutea (CL), while atrazine stimulates new CL. Bromocriptine (BRC) is known to suppress the luteolysis in rats. This study investigated the light- and electron-microscopic luteal changes induced by EGME, atrazine, or BRC. Female rats were treated with EGME (300 mg/kg/day), BRC (2 mg/kg/day), EGME and BRC (EGME + BRC), or atrazine (300 mg/kg/day) for 7 days. Luteal cell hypertrophy induced by EGME, EGME + BRC, and atrazine was subclassified into the following two types: CL hypertrophy, vacuolated type (CL-V) characterized by intracytoplasmic fine vacuoles, and CL hypertrophy, eosinophilic type (CL-E) characterized by eosinophilic and abundant cytoplasm. The proportions of CL-V and CL-E were different among the treatments. BRC-treated old CL showed lower proportion of endothelial cells and fibroblasts than normal old CL. Ultrastructural observation revealed that the luteal cells of CL-V contained abundant lipid droplets, whereas those of CL-E in EGME and EGME + BRC groups showed uniformly well-developed smooth endoplasmic reticulum. No clear ultrastructural difference was observed between the control CL and atrazine-treated CL-E. These results indicate that EGME, atrazine, and BRC have differential luteal morphological effects.

  17. Effect of hematoporphyrin monomethyl ether-sonodynamic therapy (HMME-SDT on hypertrophic scarring.

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    Hanjun Zhang

    Full Text Available OBJECTIVE: The aim of the present study was to explore the potential for hematoporphyrin monomethyl ether-Sonodynamic Therapy (HMME-SDT treatment of hypertrophic scars within rabbit ears. METHODS: 60 white rabbits were randomly divided into five groups: (1 untreated controls, (2 lesioned, (3 lesioned + HMME, (4 lesioned + US (Ultrasound, and (5 lesioned +HMME-SDT. After induction of a lesion upon the ears of the rabbits, hypertrophic scars were assessed at 14, 28, 42 and 56 days post-lesion +/- treatment. Assessments consisted of visual inspection in the change of the skin, scar formation pathological morphology by hematoxylin and eosin (HE staining technique with optical microscopy, calculation of a hypertrophic index, fibroblastic density measures, and observation of collagen changes in the scar tissue by Van Gieson's (VGStain along with calculation of collagen area density. RESULTS: With continued HMME-SDT treatment there was a gradual improvement in all parameters over the duration of the experiment. The lesion-induced scars of rabbits receiving HMME-SDT treatment were soft, the size was reduced, hyperplasia was flat and the color pale. The fibroblasts and collagens were reduced and the collagens were light red, sparse and orderly. The hypertrophic index was reduced, since the fibroblastic density was lowered and collagen area density was decreased. CONCLUSION: HMME is an effective sonosensitizer and the combination of HMME-SDT treatment can exert significant benefits in reducing the formation of hypertrophic scars.

  18. Photodynamic inactivation of antibiotic-resistant bacteria and biofilms by hematoporphyrin monomethyl ether.

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    Liu, Chengcheng; Hu, Min; Ma, Dandan; Lei, Jin'e; Xu, Jiru

    2016-02-01

    The worldwide increase in bacterial antibiotic resistance has led to a search for alternative antibacterial therapies. A promising approach to killing antibiotic-resistant bacteria is photodynamic antimicrobial chemotherapy, which uses light in combination with a photosensitizer to induce a phototoxic reaction. We evaluated the photodynamic inactivation (PDI) efficiency of hematoporphyrin monomethyl ether (HMME) on antibiotic-resistant bacteria and biofilms. HMME exhibited no significant dark toxicity and provided dose-dependent inactivation of antibiotic-resistant bacteria and biofilms. After incubation with 100-μM HMME and irradiation with 72-J cm(-2) white light, 4.19-7.59 log10 reductions in survival were achieved in planktonic suspension. Antibiotic-resistant strains were as susceptible to PDI in biofilms as in planktonic suspensions, but the inactivation of bacterial cells in biofilms was attenuated. In addition, gram-positive bacterial strains and biofilms were more susceptible than gram-negative strains and biofilms to the PDI effect of HMME. Thus, HMME is a promising photosensitizer for the treatment of infectious diseases caused by antibiotic-resistant bacteria, especially gram-positive bacteria.

  19. Effects of sulpiride and ethylene glycol monomethyl ether on endometrial carcinogenicity in Donryu rats.

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    Taketa, Yoshikazu; Inoue, Kaoru; Takahashi, Miwa; Sakamoto, Yohei; Watanabe, Gen; Taya, Kazuyoshi; Yoshida, Midori

    2016-06-01

    Sulpiride and ethylene glycol monomethyl ether (EGME) are known ovarian toxicants that stimulate prolactin (PRL) secretion, resulting in hypertrophy of the corpora lutea and increased progesterone (P4) production. The purpose of the present study was to investigate how the PRL stimulatory agents affected uterine carcinogenesis and to clarify the effects of PRL on endometrial adenocarcinoma progression in rats. Ten-week-old female Donryu rats were treated once with N-ethyl-N'-nitro-N-nitrosoguanidine (20 mg kg(-1) ), followed by treatment with sulpiride (200 ppm) or EGME (1250 ppm) from 11 weeks of age to 12 months of age. Sulpiride treatment inhibited the incidence of uterine adenocarcinoma and precancerous lesions of atypical endometrial hyperplasia, whereas EGME had no effect on uterine carcinogenesis. Sulpiride markedly prevented the onset of persistent estrus throughout the study period, and EGME delayed and inhibited the onset of persistent estrus. Moreover, sulpiride-treated animals showed high PRL and P4 serum levels without changes in the levels of estradiol-17β, low uterine weights and histological luteal cell hypertrophy. EGME did not affect serum PRL and P4 levels. These results suggest that the prolonged low estradiol-17β to P4 ratio accompanied by persistent estrous cycle abnormalities secondary to the luteal stimulatory effects of PRL may explain the inhibitory effects of sulpiride on uterine carcinogenesis in rats. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Impact of water activity and temperature on growth and alternariol and alternariol monomethyl ether production of Alternaria alternata isolated from soybean.

    Science.gov (United States)

    Oviedo, M S; Ramirez, M L; Barros, G G; Chulze, S N

    2010-02-01

    The objective of this study was to determine the effect of water activity (a(w); 0.995, 0.98, 0.96, 0.94, 0.92, and 0.90), temperature (5, 18, 25, and 30 degrees C), incubation time (7 to 35 days), and their interactions on mycelial growth and alternariol (AOH) and alternariol monomethyl ether (AME) production. Two Alternaria alternata strains isolated from soybeans in Argentina were grown on 2% soybean extract agar. Maximum growth rates were obtained at the highest a(w) (0.995) and 25 degrees C, with growth decreasing as the water availability of the medium was reduced. Maximum amount of AOH was produced at 0.98 a(w) and 25 degrees C for both strains. Maximum AME production was obtained for both strains at 30 degrees C but different a(w) values, 0.92 and 0.94, for the strains RC 21 and RC 39, respectively. The concentrations of both toxins varied considerably depending on the a(w) and temperature interactions assayed. The two metabolites were produced from 5 to 30 degrees C and at a(w) values of 0.92 to 0.995. Although at 5 and 18 degrees C little mycotoxin was produced at a(w) lower than 0.94. Two-dimensional profiles of a(w) by temperature interactions were developed from these data to identify areas where conditions indicate a significant risk from AOH and AME accumulation on soybeans. All the conditions of a(w) and temperature that resulted in maximum production of both toxins are those found during soybean development in the field. Thus, field conditions are likely to be conducive to optimum A. alternata growth and toxin production.

  1. Screening for occupational vitiligo in workers exposed to hydroquinone monomethyl ether and to paratertiary-amyl-phenol

    Energy Technology Data Exchange (ETDEWEB)

    O' Sullivan, J.J.; Stevenson, C.J.

    1981-11-01

    Two men reported previously with vitiligo after occupational exposure to hydroquinone monomethyl ether (HMME) have been reviewed after eight years. Repigmentation of significant degree was found in one man and of limited degree in the other. One hundred and sixty-nine men in the same works have been screened with Wood's light for evidence of vitiligo. No cases were found in the 148 men exposed to HMME (colleagues who screened 100 men exposed to HMME in two other factories also found no case) or in the 129 who had been exposed to paratertiary-amyl-phenol. Loss of light reflection on Wood's light examination was observed in 13 men due to scars or to other skin disorders.

  2. Effects of gamma irradiation on the fungus Alternaria alternata and on mycotoxins Alternariol and Alternariol monomethyl ether in artificially contaminated cereal samples;Efeitos da radiacao gama no fungo Alternaria alternata e nas micotoxinas Alternariol e Alternariol monometil eter em amostras de cereais artificialmente contaminadas

    Energy Technology Data Exchange (ETDEWEB)

    Braghini, Raquel

    2009-07-01

    The present study aimed to evaluate the effects of different gamma irradiation doses on the growth of Alternaria alternata and on production of mycotoxins Alternariol (AOH) and Alternariol Monomethyl Ether (AME) in cereal samples. The results showed a significant reduction in the number of CFU/g in rice grains and sunflower seeds, which were proportional to radiation dose used. However, in corn and wheat grains was observed an increase in the number of CFU/g with the increase of gamma irradiation. The radiation doses used resulted in a reduction of AOH levels. In rice and corn grains, the production of AOH was highest in the group irradiated with 5 kGy. Similar result was obtained with relation to AME. Scanning electron microscopy made it possible to visualize structural alterations on A. alternata induced by the different g-radiation doses used. Analysis of irradiated AOH and AME toxins standards did not show any alteration comparing to the control group. (author)

  3. Evaluation of Hydrogel Suppositories for Delivery of 5-Aminolevulinic Acid and Hematoporphyrin Monomethyl Ether to Rectal Tumors.

    Science.gov (United States)

    Ye, Xuying; Yin, Huijuan; Lu, Yu; Zhang, Haixia; Wang, Han

    2016-10-12

    We evaluated the potential utility of hydrogels for delivery of the photosensitizing agents 5-aminolevulinic acid (ALA) and hematoporphyrin monomethyl ether (HMME) to rectal tumors. Hydrogel suppositories containing ALA or HMME were administered to the rectal cavity of BALB/c mice bearing subcutaneous tumors of SW837 rectal carcinoma cells. For comparison, ALA and HMME were also administered by three common photosensitizer delivery routes; local administration to the skin and intratumoral or intravenous injection. The concentration of ALA-induced protoporphyrin IX or HMME in the rectal wall, skin, and subcutaneous tumor was measured by fluorescence spectrophotometry, and their distribution in vertical sections of the tumor was measured using a fluorescence spectroscopy system. The concentration of ALA-induced protoporphyrin IX in the rectal wall after local administration of suppositories to the rectal cavity was 9.76-fold (1 h) and 5.8-fold (3 h) higher than in the skin after cutaneous administration. The maximal depth of ALA penetration in the tumor was ~3-6 mm at 2 h after cutaneous administration. Much lower levels of HMME were observed in the rectal wall after administration as a hydrogel suppository, and the maximal depth of tumor penetration was suppository is thus a potential delivery route for photodynamic therapy of rectal cancer.

  4. Evaluation of Hydrogel Suppositories for Delivery of 5-Aminolevulinic Acid and Hematoporphyrin Monomethyl Ether to Rectal Tumors

    Directory of Open Access Journals (Sweden)

    Xuying Ye

    2016-10-01

    Full Text Available We evaluated the potential utility of hydrogels for delivery of the photosensitizing agents 5-aminolevulinic acid (ALA and hematoporphyrin monomethyl ether (HMME to rectal tumors. Hydrogel suppositories containing ALA or HMME were administered to the rectal cavity of BALB/c mice bearing subcutaneous tumors of SW837 rectal carcinoma cells. For comparison, ALA and HMME were also administered by three common photosensitizer delivery routes; local administration to the skin and intratumoral or intravenous injection. The concentration of ALA-induced protoporphyrin IX or HMME in the rectal wall, skin, and subcutaneous tumor was measured by fluorescence spectrophotometry, and their distribution in vertical sections of the tumor was measured using a fluorescence spectroscopy system. The concentration of ALA-induced protoporphyrin IX in the rectal wall after local administration of suppositories to the rectal cavity was 9.76-fold (1 h and 5.8-fold (3 h higher than in the skin after cutaneous administration. The maximal depth of ALA penetration in the tumor was ~3–6 mm at 2 h after cutaneous administration. Much lower levels of HMME were observed in the rectal wall after administration as a hydrogel suppository, and the maximal depth of tumor penetration was <2 mm after cutaneous administration. These data show that ALA more readily penetrates the mucosal barrier than the skin. Administration of ALA as an intrarectal hydrogel suppository is thus a potential delivery route for photodynamic therapy of rectal cancer.

  5. pH-Responsive Polyethylene Glycol Monomethyl Ether-ε-Polylysine-G-Poly (Lactic Acid)-Based Nanoparticles as Protein Delivery Systems

    OpenAIRE

    Liu, Huiqin; Li, Yijia; Yang, Rui; Gao, Xiujun; Ying, Guoguang

    2016-01-01

    The application of poly(lactic acid) for sustained protein delivery is restricted by the harsh pH inside carriers. In this study, we synthesized a pH-responsive comb-shaped block copolymer, polyethylene glycol monomethyl ether-ε-polylysine-g-poly (lactic acid) (PEP)to deliver protein (bovine serum albumin (BSA)). The PEP nanoparticles could automatically adjust the internal pH to a milder level, as shown by the quantitative ratio metric results. The circular dichroism spectra showed that prot...

  6. The application of hyaluronic acid-derivatized carbon nanotubes in hematoporphyrin monomethyl ether-based photodynamic therapy for in vivo and in vitro cancer treatment

    Directory of Open Access Journals (Sweden)

    Shi J

    2013-07-01

    Full Text Available Jinjin Shi,* Rourou Ma,* Lei Wang, Jing Zhang, Ruiyuan Liu, Lulu Li, Yan Liu, Lin Hou, Xiaoyuan Yu, Jun Gao, Zhenzhong Zhang School of Pharmaceutical Sciences, Zhengzhou University, Zhengzhou, Henan, People's Republic of China*These authors contributed equally to this workAbstract: Carbon nanotubes (CNTs have shown great potential in both photothermal therapy and drug delivery. In this study, a CNT derivative, hyaluronic acid-derivatized CNTs (HA-CNTs with high aqueous solubility, neutral pH, and tumor-targeting activity, were synthesized and characterized, and then a new photodynamic therapy agent, hematoporphyrin monomethyl ether (HMME, was adsorbed onto the functionalized CNTs to develop HMME-HA-CNTs. Tumor growth inhibition was investigated both in vivo and in vitro by a combination of photothermal therapy and photodynamic therapy using HMME-HA-CNTs. The ability of HMME-HA-CNT nanoparticles to combine local specific photodynamic therapy with external near-infrared photothermal therapy significantly improved the therapeutic efficacy of cancer treatment. Compared with photodynamic therapy or photothermal therapy alone, the combined treatment demonstrated a synergistic effect, resulting in higher therapeutic efficacy without obvious toxic effects to normal organs. Overall, it was demonstrated that HMME-HA-CNTs could be successfully applied to photodynamic therapy and photothermal therapy simultaneously in future tumor therapy.Keywords: photodynamic therapy, photothermal therapy, HA-derivatized carbon nanotubes, tumor targeting, synergistic effect, hematoporphyrin monomethyl ether

  7. 肌醇的天然单甲醚类衍生物研究进展%Nature monomethyl ether derivatives of inositol:research progress

    Institute of Scientific and Technical Information of China (English)

    马杰; 王海勇; 薛晓文

    2014-01-01

    肌醇是自然界中广泛存在的一种六元醇,有广泛的生理、生化作用,特别是能够促进肝和其他组织中的脂肪代谢、降低血中胆固醇,临床用于治疗脂肪肝、肝硬化,动脉硬化及高血脂症。近年来,一些肌醇衍生物已被报道具有其他生物活性,包括降血糖、镇咳,抗炎等作用,其中,松醇、白坚木皮醇、红杉醇等肌醇单甲醚类衍生物的研究较为深入,本文重点对这些肌醇单甲醚类衍生物的生物活性、提取制备和开发应用等方面进行综述。%Inositol,a hexol widely found in nature with a wide range of physiological and biochemical effects,can promote fat metabolism in liver and other tissues and lower blood cholesterol and thus has been used for the clinical treatment of fatty liver, cirrhosis,atherosclerosis and hyperlipidemia. Some derivatives of inositol have been reported to have different biological activities including hypoglycemic,antitussive,anti-inflammatory and other effects. In recent years,its monomethyl ether derivatives,such as pinitol,quebrachitol,and sequoyiol,have been studied widely. In this paper,the bioactivity,extraction,preparation and applications of these monomethyl ether derivatives of inositol are reviewed.

  8. Thermal Conductivity of Liquid Diethylene Glycol Monomethyl Ether%二乙二醇单甲醚液相导热系数的实验研究

    Institute of Scientific and Technical Information of China (English)

    刘雅珺; 李晓静; 吴江涛

    2011-01-01

    利用钽丝作为热线的瞬态双热线系统对温度区间233-373K、压力区间为0.1—30 MPa的液相二乙二醇单甲醚(diethylene glycol monom ethylether,DGMME)的导热系数进行了实验研究,并将实验数据拟合为温度和压力的关联式。实验数据与导热系数关联式计算结果的标准偏差和最大偏差分别为0.23%和0.86%,导热系数的合成标准不确定度小于±1.0%。%The thermal conductivity of liquid diethylene glycol monomethyl ether (DEGMME) was measured from 233 to 373 K and pressures from 0.1 to 30 MPa, by the transient hot-wire technique employing two anodized tantalum hot wires. The experimental data was correlated as a function of temperature and pressure. The absolute average deviation and the maximum deviation of the experimental results from the correlated equation were 0.23% and 0.86%. The uncertainty of the thermal conductivity was 11.0% with a coverage factor of k ±2.

  9. Comparative Environmental Performance of Two-Diesel-Fuel Oxygenates: Dibutyl Maleate (DBM) and Triproplyene Glycol Monomethyl Ether (TGME)

    Energy Technology Data Exchange (ETDEWEB)

    Layton, D.W.; Marchetti, A.A.

    2001-10-01

    Many studies have shown that the addition of oxygen bearing compounds to diesel fuel can significantly reduce particulate emissions. To assist in the evaluation of the environmental performance of diesel-fuel oxygenates, we have implemented a suite of diagnostic models for simulating the transport of compounds released to air, water, and soils/groundwater as well as regional landscapes. As a means of studying the comparative performance of DBM and TGME, we conducted a series of simulations for selected environmental media. Benzene and methyl tertiary butyl ether (MTBE) were also addressed because they represent benchmark fuel-related compounds that have been the subject of extensive environmental measurements and modeling. The simulations showed that DBM and TGME are less mobile in soil because of reduced vapor-phase transport and increased retention on soil particles. The key distinction between these two oxygenates is that DBM is predicted to have a greater potential than TGME for aerobic biodegradation, based on chemical structure.

  10. HematoPorphyrin Monomethyl Ether polymer contrast agent for ultrasound/photoacoustic dual-modality imaging-guided synergistic high intensity focused ultrasound (HIFU) therapy

    Science.gov (United States)

    Yan, Sijing; LU, Min; Ding, Xiaoya; Chen, Fei; He, Xuemei; Xu, Chunyan; Zhou, Hang; Wang, Qi; Hao, Lan; Zou, Jianzhong

    2016-01-01

    This study is to prepare a hematoporphyrin monomethyl ether (HMME)-loaded poly(lactic-co-glycolic acid) (PLGA) microcapsules (HMME/PLGA), which could not only function as efficient contrast agent for ultrasound (US)/photoacoustic (PA) imaging, but also as a synergistic agent for high intensity focused ultrasound (HIFU) ablation. Sonosensitizer HMME nanoparticles were integrated into PLGA microcapsules with the double emulsion evaporation method. After characterization, the cell-killing and cell proliferation-inhibiting effects of HMME/PLGA microcapsules on ovarian cancer SKOV3 cells were assessed. The US/PA imaging-enhancing effects and synergistic effects on HIFU were evaluated both in vitro and in vivo. HMME/PLGA microcapsules were highly dispersed with well-defined spherical morphology (357 ± 0.72 nm in diameter, PDI = 0.932). Encapsulation efficiency and drug-loading efficiency were 58.33 ± 0.95% and 4.73 ± 0.15%, respectively. The HMME/PLGA microcapsules remarkably killed the SKOV3 cells and inhibited the cell proliferation, significantly enhanced the US/PA imaging results and greatly enhanced the HIFU ablation effects on ovarian cancer in nude mice by the HMME-mediated sono-dynamic chemistry therapy (SDT). HMME/PLGA microcapsules represent a potential multifunctional contrast agent for HIFU diagnosis and treatment, which might provide a novel strategy for the highly efficient imaging-guided non-invasive HIFU synergistic therapy for cancers by SDT in clinic. PMID:27535093

  11. Differential stimulation pathways of progesterone secretion from newly formed corpora lutea in rats treated with ethylene glycol monomethyl ether, sulpiride, or atrazine.

    Science.gov (United States)

    Taketa, Yoshikazu; Yoshida, Midori; Inoue, Kaoru; Takahashi, Miwa; Sakamoto, Yohei; Watanabe, Gen; Taya, Kazuyoshi; Yamate, Jyoji; Nishikawa, Akiyoshi

    2011-06-01

    Ethylene glycol monomethyl ether (EGME), sulpiride, and atrazine are known ovarian toxicants, which increase progesterone (P4) secretion and induce luteal cell hypertrophy following repeated administration. The aim of this study was to define the pathways by which these compounds exerted their effects on the ovary and hypothalamic-pituitary-gonadal (HPG) axis. In the ovary, changes in the steroidogenic activity of new and old corpora lutea (CL) were addressed. EGME (300 mg/kg), sulpiride (100 mg/kg), or atrazine (300 mg/kg) were orally given daily for four times from proestrus to diestrus in normal cycling rats. Treatment with all chemicals significantly increased serum P4 levels, and EGME as well as sulpiride induced increases in prolactin (PRL) levels. In new CL, at both the gene and the protein levels, all three chemicals upregulated the following steroidogenic factors: scavenger receptor class B type I, steroidogenic acute regulatory protein, P450 cholesterol side-chain cleavage, and 3β-hydroxysteroid dehydrogenase (HSD) and downregulated the luteolytic gene, 20α-HSD. Coadministration of EGME and bromocriptine, a D2 agonist, completely inhibited PRL but not P4 secretion. Additionally, steroidogenic factor expression levels were upregulated, and 20α-HSD level was downregulated in new CL. These results suggest that EGME both directly and indirectly stimulates P4 production in luteal cells, whereas sulpiride elevates P4 through activation of PRL secretion in the pituitary. Atrazine may directly activate new CL by stimulating steroidogenic factor expressions. The present study suggests that multiple pathways mediate the effects of EGME, sulpiride, and atrazine on the HPG axis and luteal P4 production in female rats in vivo.

  12. HematoPorphyrin Monomethyl Ether polymer contrast agent for ultrasound/photoacoustic dual-modality imaging-guided synergistic high intensity focused ultrasound (HIFU) therapy

    Science.gov (United States)

    Yan, Sijing; Lu, Min; Ding, Xiaoya; Chen, Fei; He, Xuemei; Xu, Chunyan; Zhou, Hang; Wang, Qi; Hao, Lan; Zou, Jianzhong

    2016-08-01

    This study is to prepare a hematoporphyrin monomethyl ether (HMME)-loaded poly(lactic-co-glycolic acid) (PLGA) microcapsules (HMME/PLGA), which could not only function as efficient contrast agent for ultrasound (US)/photoacoustic (PA) imaging, but also as a synergistic agent for high intensity focused ultrasound (HIFU) ablation. Sonosensitizer HMME nanoparticles were integrated into PLGA microcapsules with the double emulsion evaporation method. After characterization, the cell-killing and cell proliferation-inhibiting effects of HMME/PLGA microcapsules on ovarian cancer SKOV3 cells were assessed. The US/PA imaging-enhancing effects and synergistic effects on HIFU were evaluated both in vitro and in vivo. HMME/PLGA microcapsules were highly dispersed with well-defined spherical morphology (357 ± 0.72 nm in diameter, PDI = 0.932). Encapsulation efficiency and drug-loading efficiency were 58.33 ± 0.95% and 4.73 ± 0.15%, respectively. The HMME/PLGA microcapsules remarkably killed the SKOV3 cells and inhibited the cell proliferation, significantly enhanced the US/PA imaging results and greatly enhanced the HIFU ablation effects on ovarian cancer in nude mice by the HMME-mediated sono-dynamic chemistry therapy (SDT). HMME/PLGA microcapsules represent a potential multifunctional contrast agent for HIFU diagnosis and treatment, which might provide a novel strategy for the highly efficient imaging-guided non-invasive HIFU synergistic therapy for cancers by SDT in clinic.

  13. 减压条件下催化酯化合成聚乙二醇单甲醚丙烯酸酯%Synthesis of polyethylene glycol monomethyl ether acrylate by esterification under vacuum condition

    Institute of Scientific and Technical Information of China (English)

    于二雷; 张乐涛; 蔡国星; 周亮; 吾满江·艾力

    2013-01-01

    Polyethylene glycol monomethyl ether acrylate (MPEGAA) was the important monomer for synthesis of comb dispersant.Using p-toluene sulphonic acid as the catalyst,MPEGAA was synthezied by the esterification of polyethylene glycol monomethyl ether (MPEG400) and acrylic acid under vacuum.The structure of the product was characterized by Fourier transform infrared spectroscopy.The results showed that the esterification rate of 92.6% was attained under the optimum reaction condition as follows:reaction temperature 90 ℃,reaction pressure 0.06 MPa,catalyst dosage 2.0% of total mass of the reactants,inhibitor amount 1.5% of acrylic acid mass,molar ratio of acrylic acid to MPEG400 =3∶1 and reaction time 5 h.The results of HPLC analysis indicated that the purity of the product extracted with saturated brine and ethyl acetate was 99.2%.%聚乙二醇单甲醚丙烯酸酯是合成梳形分散剂的重要单体.以聚乙二醇单甲醚和丙烯酸为原料,对甲苯磺酸为催化剂,减压条件下直接酯化合成聚乙二醇单甲醚丙烯酸酯,采用傅立叶红外光谱表征产物结构.对反应条件进行了优化,结果表明,在温度90℃、压力0.06 MPa、催化剂用量为反应物总质量的2.0%、阻聚剂用量为丙烯酸质量的1.5%、丙烯酸与聚乙二醇单甲醚物质的量比3∶1和反应时间5h条件下,酯化率可达92.6%.高效液相色谱分析证明,用饱和食盐水和乙酸乙酯萃取后的产物纯度为99.2%.

  14. Synthesis of Diethylene Glycol Monomethyl Ether Cottonseed Oil Monoester as a Novel Biodiesel%棉籽油二乙二醇甲醚酯新型生物柴油制备

    Institute of Scientific and Technical Information of China (English)

    李正正; 郭和军; 苏俊作; 王汝栋

    2012-01-01

    以精制棉籽油、无水甲醇和二乙二醇单甲醚为原料,KOH为催化剂,通过酯交换反应制备出一种高含氧量的新型生物柴油;采用正交试验研究了醇油比、催化剂用量、温度和反应时间对产率的影响,得出了最佳合成条件;运用红外光谱法、核磁共振法、凝胶渗透色谱法进行了产物结构表征;此外柴油机台架试验也表明燃烧该新型生物柴油可有效减少柴油机的废气排放.%Using diethylene glycol monomethyl ether,anhydrous methanol and cottonseed oil as raw materials and KOH as catalyst ,a novel biodiesel with high oxygen content was synthesized by transesterification reaction. The orthogonal test with four-factor and three-level was used to investigate effects of molar ratio of methanol to cottonseed oil, catalyst dosage, temperature and reaction time on the yield, and optimal reaction conditions were gained. Chemical structure of the new biodiesel was characterized by FT-IR,1H NMR and GPC. A single cylinder, 4-stroke, water-cooled, DI diesel engine was adopted to determine exhaust emissions when using the novel biodiesel.

  15. Effect of Hematoporphyrin Monomethyl Ether Mediated Photodynamic Therapy on Mice Contact Hypersensitivity%血卟啉单甲醚光动力学疗法对小鼠接触性超敏反应的抑制效应

    Institute of Scientific and Technical Information of China (English)

    邱海霞; 刘红梅; 顾瑛; 李德生; 曾耀英; 何贤辉; 刘丽红

    2008-01-01

    目的 探讨血卟啉单甲醚光动力学疗法(hematoporphyrin monomethyl ether mediated photodynamic therapy,HMME-PDT)对小鼠接触性超敏反应(contact hypersensitivity,CHS)的影响.方法 雌性BALB/c小鼠按功率密度分为50和100mW/cm2两个实验组,同时设置单纯照光组、单纯光敏剂组、空白对照组以及DNFB组.PDT处理后3 d,各实验组分别以2,4-二硝基氟苯(DNFB)诱发小鼠右耳变应性接触性皮炎,以游标卡尺测量发敏前后右耳的厚度差;对于功率密度为50 mW/cm2组,进一步观察了PDT处理前4 d或PDT处理后1、3和12 d,DNFB发敏前后小鼠右耳的厚度差,并对PDT后3 d组行组织学检查,以目镜网格测微尺计算浸润炎症细胞数量.结果 处理前4d预先以DNFB致敏,PDT对CHS无抑制作用(P>0.05).反之,PDT照射后1、3或12 d再以DNFB致敏,则PDT能对CHS产生显著抑制作用(P<0.01),其抑制率分别为58%,63%,47%.且无论是以50mW/cm2还是以100mW/cm2功率密度的激光照射,这种抑制作用均存在.未经任何干预,DNFB致敏组致敏右耳浸润的单核细胞和中性粒细胞的数量增加,而经PDT处理后,浸润的炎性细胞明显减少,二者之间存在显著性差异(P<0.01).结论 HMME-PDT能对正常小鼠接触性超敏反应产生明显抑制作用,并有短暂持续效应.

  16. Mechanisms of Anti-microbial Photodynamic Technology Against Listeria monocytogenes by Hematoporyrin Monomethyl Ether%血啉甲醚对单增李斯特菌的光动力灭活作用及机理

    Institute of Scientific and Technical Information of China (English)

    林少玲; 唐书泽; 唐姝姝; 吴希阳; 陈振强

    2011-01-01

    Anti-microbial photodynamic technology (APDT) on L.monocytogenes was conducted using photo sensitizer hematoporyrin monomethyl ether (HMME) followed by tungsten-halogen lamp ( power density 200 mW/cm2 ).The bactericidal effects were measured by counting the reduction of colony forming unit (CFU) after APDT-HMME treatment.The degradation of protein was observed under sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE), and the damage of DNA was investigated by polymerase chain reaction (PCR).Approximately 99.9999% of L.monocytogenes were photo inactivated by illumination with 30 min visible light in the presence of 25 μg/mL HMME.The cell killing effect to L.monocytogenes with illumination was much greater than in the dark at the same concentration of HMME.The protein of L.monocytogeneirradiated with HMME and visible light for 30 min was degraded obviously shown by SDS-PAGE graph and the DNA damage shown by PCR graph was greater in APDT-treated groups compared with the control groups.The significant cell killing effect of APDT-HMME on L.monocytogenes may be explained by the bactericidal mechanism through the degradation of the protein and the damage of DNA.%通过平板菌落计数法研究血啉甲醚对单增李斯特茵的光动力灭活作用,同时采用聚丙烯酰胺凝胶电泳和聚合酶链式反应分析光动力灭菌技术对单增李斯特菌蛋白降解效果和基因组DNA的损伤程度.实验发现浓度为25μg/mL的血啉甲醚在光功密度为200 mW/cm2的溴钨灯光照射30 min杀灭了99.9999%的单增李斯特菌,并导致了其蛋白质降解和基因组DNA片段断裂.血啉甲醚对单增李斯特菌的光动力灭活作用非常显著,其灭活机理可能是通过对蛋白质降解和基因组DNA损伤实现的.

  17. Propylene Glycol Monomethyl Ether Acetate Catalytic Synthesis by Solid Super Acid(SO2-4/ZrO2)%固体超强酸(SO2-4/ZrO2)催化合成丙二醇甲醚醋酸酯

    Institute of Scientific and Technical Information of China (English)

    叶四华; 王鹏; 于冬娥

    2015-01-01

    采用固体超强酸(SO2-4/ZrO2)催化剂,丙二醇甲醚(PM)和冰醋酸(HAc)为原料进行酯化反应合成丙二醇甲醚醋酸酯(PMA)。考察了原料配比、催化剂用量、带水剂用量、反应时间以及反应温度等因素对反应的影响。结果表明,当丙二醇甲醚与冰醋酸摩尔比为1∶1.5,催化剂用量为反应物总质量的3.6%,带水剂用量为 反 应 物 总 质 量 的30%,反 应 温 度 为105~112℃且反应4.2 h 时,丙二醇甲醚醋酸酯收率可达98.84%。%Propylene glycol monomethyl ether acetate(PMA)was synthesized from propylene glycol monomethyl ether(PM)and glycial acetic acid(HAc)with solid super acid(SO2 -4 /ZrO2)as catalyst. It examines the effects of ratio,catalyst amount,water content,reaction time and reaction temperature on reaction.

  18. Autonomy @ Ames

    Science.gov (United States)

    Van Dalsem, William; Krishnakumar, Kalmanje Srinivas

    2016-01-01

    This is a powerpoint presentation that highlights autonomy across the 15 NASA technology roadmaps, including specific examples of projects (past and present) at NASA Ames Research Center. The NASA technology roadmaps are located here: http:www.nasa.govofficesocthomeroadmapsindex.html

  19. NASA Ames ATM Research

    Science.gov (United States)

    Denery, Dallas G.

    2000-01-01

    The NASA Ames research Center, in cooperation with the FAA and the industry, has a series of major research efforts underway that are aimed at : 1) improving the flow of traffic in the national airspace system; and 2) helping to define the future air traffic management system. The purpose of this presentation will be to provide a brief summary of some of these activities.

  20. Rotorcraft simulation at Ames

    Science.gov (United States)

    Alderete, T. S.

    1984-01-01

    Attention is given to rotorcraft simulation experience at NASA's Ames research facility, which has involved complex mathematical modeling, high computational capability requirements, and strong influences from pilot motion and visual cues. A development history and performance assessment is presented for the rotorcraft simulation hardware, together with projections of near term development improvements of capabilities. Greater demand is anticipated for the simulation of all-digital helicopter flight control systems.

  1. Effect of Diethylene Glycol Monomethyl Ether (DiEGME) and Triethylene Glycol Monomethyl Ether (TriEGME) on Microbial Contaminants in Aviation Fuel

    Science.gov (United States)

    2010-03-01

    resinae (ATCC # 20495), and Yarrowia (Candida) tropicalis (ATCC # 20336). P. aeruginosa is a type of bacteria, C. resinae is a fungus, and C. tropicalis...The C. resinae originated from an aircraft fuel tank and was deposited by J. J. Marshall from the NLABS collection in 1977. The C. tropicalis was...species, a Pseudomonas species, Bacillus licheniformis, Clostridium intestinale, Rhodococcus equi, and Hormoconis (Cladosporium) resinae . All are bacteria

  2. Routine environmental audit of Ames Laboratory, Ames, Iowa

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-09-01

    This document contains the findings identified during the routine environmental audit of Ames Laboratory, Ames, Iowa, conducted September 12--23, 1994. The audit included a review of all Ames Laboratory operations and facilities supporting DOE-sponsored activities. The audit`s objective is to advise the Secretary of Energy, through the Assistant Secretary for Environment, Safety and Health, as to the adequacy of the environmental protection programs established at Ames Laboratory to ensure the protection of the environment, and compliance with Federal, state, and DOE requirements.

  3. Comparative evaluation of biochemical changes in tomato (Lycopersicon esculentum Mill. infected by Alternaria alternata and its toxic metabolites (TeA, AOH and AME

    Directory of Open Access Journals (Sweden)

    Mukesh Meena

    2016-09-01

    Full Text Available In the present study, we have evaluated the comparative biochemical defense response generated against Alternaria alternata and its purified toxins viz. alternariol (AOH, alternariol monomethyl ether (AME and tenuazonic acid (TeA. The necrotic lesions developed due to treatment with toxins were almost similar as those produced by pathogen, indicating the crucial role of these toxins in plant pathogenesis. An oxidative burst reaction characterized by the rapid and transient production of a large amount of reactive oxygen species (ROS occurs following the pathogen infection/toxin exposure. The maximum concentration of H2O2 produced was reported in pathogen infected samples (22.2-fold at 24 h post inoculation followed by TeA (18.2-fold, AOH (15.9-fold, and AME (14.1-fold in treated tissues. DAB staining predicted the possible sites of H2O2 accumulation while the extent of cell death were measured by Evans blue dye. The extent of lipid peroxidation and MDA content was higher (15.8-fold at 48 h in the sample of inoculated leaves of pathogen, when compared to control. The cellular damages were observed as increased MDA content and reduced chlorophyll. The activities of antioxidative defense enzymes increased in both pathogen infected as well as toxin treated samples. SOD, activity was 5.9- fold higher at 72 h post inoculation in leaves followed by TeA (5.0-fold, AOH (4.1-fold and AME (2.3-fold treated leaves than control. Catalase activity was found to be increased upto 48 h post inoculation and maximum in pathogen challenged samples followed by other toxins. The native PAGE results showed the variations in the intensities of isozyme (SOD and CAT bands in the pathogen infected and toxin treated samples. APx and GR activities followed the similar trend to scavenge the excess H2O2. The reduction in CAT activities after 48 h post inoculation demonstrate that the biochemical defense programming shown by the host against the pathogen is not well efficient

  4. Cosmic Ether

    CERN Document Server

    Tomaschitz, R

    1998-01-01

    A prerelativistic approach to particle dynamics is explored in an expanding Robertson-Walker cosmology. The receding galactic background provides a distinguished frame of reference and a unique cosmic time. In this context the relativistic, purely geometric space-time concept is criticized. Physical space is regarded as a permeable medium, the cosmic ether, which effects the world-lines of particles and rays. We study in detail a Robertson-Walker universe with linear expansion factor and negatively curved, open three-space; we choose the permeability tensor of the ether in such a way that the semiclassical approximation is exact. Galactic red-shifts depend on the refractive index of the ether. In the local Minkowskian limit the ether causes a time variation of mass, which scales inversely proportional to cosmic time. In the globally geodesic rest frames of galactic observers the ether manifests itself in an unbounded speed of signal transfer, in bifurcations of world-lines, and in time inversion effects.

  5. Environmental Survey preliminary report, Ames Laboratory, Ames, Iowa

    Energy Technology Data Exchange (ETDEWEB)

    1989-03-01

    This report presents the preliminary findings of the first phase of the environmental Survey of the United States Department of Energy's (DOE) Ames Laboratory, conducted April 18 through 22, 1988. The Survey is being conducted by an interdisciplinary team of environmental specialists, led and managed by the Office of Environment, Safety and Health's Office of Environmental Audit. Individual team members are being supplied by private contractors. The objective of the Survey is to identify environmental problems and areas of environmental risk associated with the Ames Laboratory. The Survey covers all environmental media and all areas of environmental regulation. It is being performed in accordance with the DOE Environmental Survey Manual. This phase of the Survey involves the review of existing site environmental data, observations of the operations carried on at the Ames Laboratory, and interviews with site personnel. The Survey team developed a Sampling and Analysis (S A) Plan to assist in further assessing certain of the environmental problems identified during its on-site activities. The S A plan is being developed by the Idaho National Engineering Laboratory. When S A is completed, the results will be incorporated into the Ames Laboratory Environmental Survey findings for inclusion in the Environmental Survey Summary Report. 60 refs., 13 figs., 20 tabs.

  6. NASA Ames Research Center: An Overview

    Science.gov (United States)

    Tu, Eugene; Yan, Jerry Chi Yiu

    2017-01-01

    This overview of NASA Ames Research Center is intended to give the target audience of university students a general understanding of the mission, core competencies, and research goals of NASA and Ames.

  7. AMED: The Allied and Complementary Medicine Database.

    Science.gov (United States)

    Vardell, Emily

    2016-01-01

    AMED: The Allied and Complementary Medicine Database is a resource from the Health Care Information Service of the British Library. AMED offers access to complementary and alternative medicine topics, such as acupuncture, chiropractic, herbalism, homeopathy, hospice care, hypnosis, palliative care, physiotherapy, podiatry, and rehabilitation. This column features a sample search to demonstrate the type of information available within AMED. AMED is available through the EBSCOhost and OVID platforms.

  8. NASA Ames Environmental Sustainability Report 2011

    Science.gov (United States)

    Clarke, Ann H.

    2011-01-01

    The 2011 Ames Environmental Sustainability Report is the second in a series of reports describing the steps NASA Ames Research Center has taken toward assuring environmental sustainability in NASA Ames programs, projects, and activities. The Report highlights Center contributions toward meeting the Agency-wide goals under the 2011 NASA Strategic Sustainability Performance Program.

  9. Management process invaded Ames as the Center shifted from NACA to NASA oversight. Ames constructed

    Science.gov (United States)

    1968-01-01

    Management process invaded Ames as the Center shifted from NACA to NASA oversight. Ames constructed a review room in its headquarters building where, in the graphical style that prevailed in the 1960's, Ames leadership could review progress against schedule, budget and performance measures. Shown, in October 1965 is Merrill Mead chief of Ames' program and resources office. (for H Julian Allen Retirement album)

  10. Ames Life Science Data Archive: Translational Rodent Research at Ames

    Science.gov (United States)

    Wood, Alan E.; French, Alison J.; Ngaotheppitak, Ratana; Leung, Dorothy M.; Vargas, Roxana S.; Maese, Chris; Stewart, Helen

    2014-01-01

    The Life Science Data Archive (LSDA) office at Ames is responsible for collecting, curating, distributing and maintaining information pertaining to animal and plant experiments conducted in low earth orbit aboard various space vehicles from 1965 to present. The LSDA will soon be archiving data and tissues samples collected on the next generation of commercial vehicles; e.g., SpaceX & Cygnus Commercial Cargo Craft. To date over 375 rodent flight experiments with translational application have been archived by the Ames LSDA office. This knowledge base of fundamental research can be used to understand mechanisms that affect higher organisms in microgravity and help define additional research whose results could lead the way to closing gaps identified by the Human Research Program (HRP). This poster will highlight Ames contribution to the existing knowledge base and how the LSDA can be a resource to help answer the questions surrounding human health in long duration space exploration. In addition, it will illustrate how this body of knowledge was utilized to further our understanding of how space flight affects the human system and the ability to develop countermeasures that negate the deleterious effects of space flight. The Ames Life Sciences Data Archive (ALSDA) includes current descriptions of over 700 experiments conducted aboard the Shuttle, International Space Station (ISS), NASA/MIR, Bion/Cosmos, Gemini, Biosatellites, Apollo, Skylab, Russian Foton, and ground bed rest studies. Research areas cover Behavior and Performance, Bone and Calcium Physiology, Cardiovascular Physiology, Cell and Molecular Biology, Chronobiology, Developmental Biology, Endocrinology, Environmental Monitoring, Gastrointestinal Physiology, Hematology, Immunology, Life Support System, Metabolism and Nutrition, Microbiology, Muscle Physiology, Neurophysiology, Pharmacology, Plant Biology, Pulmonary Physiology, Radiation Biology, Renal, Fluid and Electrolyte Physiology, and Toxicology. These

  11. Development and Validation of a LC-ESI-MS/MS Method for the Determination of Alternaria Toxins Alternariol, Alternariol Methyl-Ether and Tentoxin in Tomato and Tomato-Based Products

    Directory of Open Access Journals (Sweden)

    Yelko Rodríguez-Carrasco

    2016-11-01

    Full Text Available Alternaria species are capable of producing several secondary toxic metabolites in infected plants and in agricultural commodities, which play important roles in food safety. Alternaria alternata turn out to be the most frequent fungal species invading tomatoes. Alternariol (AOH, alternariol monomethyl ether (AME, and tentoxin (TEN are some of the main Alternaria mycotoxins that can be found as contaminants in food. In this work, an analytical method based on liquid chromatography (LC tandem mass spectrometry (MS/MS detection for the simultaneous quantification of AOH, AME, and TEN in tomato and tomato-based products was developed. Mycotoxin analysis was performed by dispersive liquid-liquid microextraction (DLLME combined with LC-ESI-MS/MS. Careful optimization of the MS/MS parameters was performed with an LC/MS system with the ESI interface in the positive ion mode. Mycotoxins were efficiently extracted from sample extract into a droplet of chloroform (100 µL by DLLME technique using acetonitrile as a disperser solvent. Method validation following the Commission Decision No. 2002/657/EC was carried out by using tomato juice as a blank matrix. Limits of detection and quantitation were, respectively, in the range 0.7 and 3.5 ng/g. Recovery rates were above 80%. Relative standard deviations of repeatability (RSDr and intermediate reproducibility (RSDR were ≤ 9% and ≤ 15%, respectively, at levels of 25 and 50 ng/g. Five out of 30 analyzed samples resulted positive to at least one Alternaria toxin investigated. AOH was the most common Alternaria toxin found, but at levels close to LOQ (average content: 3.75 ng/g.

  12. Development and Validation of a LC-ESI-MS/MS Method for the Determination of Alternaria Toxins Alternariol, Alternariol Methyl-Ether and Tentoxin in Tomato and Tomato-Based Products

    Science.gov (United States)

    Rodríguez-Carrasco, Yelko; Mañes, Jordi; Berrada, Houda; Juan, Cristina

    2016-01-01

    Alternaria species are capable of producing several secondary toxic metabolites in infected plants and in agricultural commodities, which play important roles in food safety. Alternaria alternata turn out to be the most frequent fungal species invading tomatoes. Alternariol (AOH), alternariol monomethyl ether (AME), and tentoxin (TEN) are some of the main Alternaria mycotoxins that can be found as contaminants in food. In this work, an analytical method based on liquid chromatography (LC) tandem mass spectrometry (MS/MS) detection for the simultaneous quantification of AOH, AME, and TEN in tomato and tomato-based products was developed. Mycotoxin analysis was performed by dispersive liquid-liquid microextraction (DLLME) combined with LC-ESI-MS/MS. Careful optimization of the MS/MS parameters was performed with an LC/MS system with the ESI interface in the positive ion mode. Mycotoxins were efficiently extracted from sample extract into a droplet of chloroform (100 µL) by DLLME technique using acetonitrile as a disperser solvent. Method validation following the Commission Decision No. 2002/657/EC was carried out by using tomato juice as a blank matrix. Limits of detection and quantitation were, respectively, in the range 0.7 and 3.5 ng/g. Recovery rates were above 80%. Relative standard deviations of repeatability (RSDr) and intermediate reproducibility (RSDR) were ≤ 9% and ≤ 15%, respectively, at levels of 25 and 50 ng/g. Five out of 30 analyzed samples resulted positive to at least one Alternaria toxin investigated. AOH was the most common Alternaria toxin found, but at levels close to LOQ (average content: 3.75 ng/g). PMID:27845716

  13. Chitosan grafted monomethyl fumaric acid as a potential food preservative.

    Science.gov (United States)

    Khan, Imran; Ullah, Shafi; Oh, Deog-Hwan

    2016-11-01

    The present study aims at in vitro antibacterial and antioxidant activity evaluation of chitosan modified with monomethyl fumaric acid (MFA) using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) as mediator. Three different kinds of chitosan derivatives Ch-Ds-1,Ch-Ds-2 and Ch-Ds-3 were synthesized by feeding different concentration of MFA. The chemical structures of resulting materials were characterized by (1)H NMR, (13)C NMR, HR-XRD, FT-IR and TNBS assay. The results showed that Ch-Ds-1, Ch-Ds-2 and Ch-Ds-3 were successfully synthesized. The % amino groups of chitosan modified by MFA were evaluated by TNBS assay and ranging from 1.82±0.05% to 7.88±0.04%. All the chitosan derivatives are readily soluble in water and swelled by dimethyl sulfoxide (DMSO), toluene and dimethyl formamide (DMF). The antioxidant activity for all the chitosan derivatives have been significantly improved (Pfood preservative and packaging material for long time food safety and security.

  14. Chronic exposures to monomethyl phthalate in Western clawed frogs.

    Science.gov (United States)

    Mathieu-Denoncourt, Justine; de Solla, Shane R; Langlois, Valerie S

    2015-08-01

    Polymer flexibility and elasticity is enhanced by plasticizers. However, plasticizers are often not covalently bound to plastics and thus can leach from products into the environment. Much research effort has focused on their effects in mammalian species, but data on aquatic species are scarce. In this study, Western clawed frog (Silurana tropicalis) embryos were exposed to 1.3, 12.3, and 128.7mg/L monomethyl phthalate (MMP) until the juvenile stage (11weeks) and to 1.3mg/L MMP until the adult stage (51weeks). MMP decreased survival, hastened metamorphosis, and biased the sex ratio toward males (2M:1F) at the juvenile stage without altering the expression of a subset of thyroid hormone-, sex steroid-, cellular stress- or transcription regulation-related genes in the juvenile frog livers. At the adult stage, exposure to MMP did not have significant adverse health effects, except that females had larger interocular distance and the expression of the heat shock protein 70 was decreased by 60% in the adult liver. In conclusion, this study shows that MMP is unlikely to threaten amphibian populations as only concentrations four orders of magnitude higher than the reported environmental concentrations altered the animal physiology. This is the first complete investigation of the effects of phthalates in a frog species, encompassing the entire life cycle of the organisms. Crown Copyright © 2015. Published by Elsevier Inc. All rights reserved.

  15. Tiger Team Assessment of the Ames Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    This report documents the Tiger Assessment of the Ames Laboratory (Ames), located in Ames, Iowa. Ames is operated for the US Department of Energy (DOE) by Iowa State University. The assessment was conducted from February 10 to March 5, 1992, under the auspices of the Office of Special Projects, Office of the Assistant Secretary of Environment, Safety and Health, Headquarters, DOE. The assessment was comprehensive, encompassing Environment, Safety, and Health (ES H) disciplines; management practices; and contractor and DOE self-assessments. Compliance with applicable Federal, State of Iowa, and local regulations; applicable DOE Orders; best management practices; and internal requirements at Ames Laboratory were assessed. In addition, an evaluation of the adequacy and effectiveness of DOE and the site contractor's management of ES H/quality assurance program was conducted.

  16. SYNTHESIS AND CHARACTERIZATION OF A NEW COMBLIKE POLYMER BASED ON POLY (VINYL METHYL ETHER-ALT-MALEIC ANHYDRIDE) BACKBONE

    Institute of Scientific and Technical Information of China (English)

    DING Liming; LIN Yunqing; ZHOU Zinan; NI Jianlong; CHEN Donglin

    1995-01-01

    A new comblike polymer host for polymer electrolyte was synthesized by reacting monomethyl ether of poly(ethylene glycol) with poly(vinyl methyl ether-alt-maleic anhydride) and endcapping the residual carboxylic acid with methanol. Butanone was selected as a solvent for the esterification in order to obtain a completely soluble product. The synthesis process was traced through by IR. Compared with the model compounds, the presumed structure of this comblike polymer has been proved to be valid by 13C NMR. The comb polymer is a white rubbery solid. It can be dissolved in butanone and THF, and manifests good film forming ability.

  17. The Effect of Diethylene Glycol Monomethyl Ether (DiEGME) on Microbial Contamination of Jet Fuel: A Minimum Concentration Study

    Science.gov (United States)

    2010-03-01

    identification are also listed elsewhere (11). Cladosporium resinae (Roswell) was identified by light microscopy, performed by Forensic Analytical of Rancho...Palm, and E. B. McCray. 2003. Fungal Databases, Systematic Botany & Mycology Laboratory http://nt.ars-grin.gov/fungaldatabases/. USDA Garrity, G

  18. Terminal Area ATM Research at NASA Ames

    Science.gov (United States)

    Tobias, Leonard

    1997-01-01

    The presentation will highlight the following: (1) A brief review of ATC research underway 15 years ago; (2) A summary of Terminal Area ATM Tool Development ongoing at NASA Ames; and (3) A projection of research activities 10-15 years from now.

  19. A Classroom Modification of the Ames Test.

    Science.gov (United States)

    Yavornitzky, Joseph; Trzeciak, Victor

    1979-01-01

    A modification of the Ames test for detecting carcinogens and mutagens using a strain of bacteria is described. A suggestion is given for checking the correctness of procedures by using particular hair dyes which have been shown to be mutogenic. (Author/SA)

  20. NASA Ames Fluid Mechanics Laboratory research briefs

    Science.gov (United States)

    Davis, Sanford (Editor)

    1994-01-01

    The Ames Fluid Mechanics Laboratory research program is presented in a series of research briefs. Nineteen projects covering aeronautical fluid mechanics and related areas are discussed and augmented with the publication and presentation output of the Branch for the period 1990-1993.

  1. AIM: Ames Imaging Module Spacecraft Camera

    Science.gov (United States)

    Thompson, Sarah

    2015-01-01

    The AIM camera is a small, lightweight, low power, low cost imaging system developed at NASA Ames. Though it has imaging capabilities similar to those of $1M plus spacecraft cameras, it does so on a fraction of the mass, power and cost budget.

  2. Systemic lupus erythematosus patients contain significantly less igm against mono-methylated lysine than healthy subjects.

    Directory of Open Access Journals (Sweden)

    Sha Guo

    Full Text Available Post-translational modifications on proteins are important in biological processes but may create neo-epitopes that induce autoimmune responses. In this study, we measured the serum IgG and IgM response to a set of non-modified or acetyl- and methyl-modified peptides corresponding to residues 1-19 of the histone 3 N-terminal tail in systemic lupus erythematosus (SLE patients and healthy subjects. Our results indicated that the SLE patients and healthy subjects produced antibodies (Abs to the peptides, but the two groups had different Ab isotype and epitope preferences. Abs to the non-modified form, H31-19, were of the IgG isotype and produced by SLE patients. They could not recognize the scrambled H31-19, which contained the same amino acid composition but a different sequence as H31-19. In comparison, healthy subjects in general did not produce IgG against H31-19. However, about 70% of the healthy subjects produced IgM Abs against mono-methylated K9 of H31-19 (H31-19K9me. Our further studies revealed that ε-amine mono-methylated lysine could completely inhibit the IgM binding to H31-19K9me, but lysine had no inhibitory effect. In addition, the IgM Abs could bind peptides containing a mono-methylated lysine residue but with totally different sequences. Thus, mono-methylated lysine was the sole epitope for the IgM. Interestingly, SLE patients had much lower levels of this type of IgM. There was no obvious correlation between the IgM levels and disease activity and the decreased IgM was unlikely caused by medical treatments.We also found that the IgM Abs were not polyreactive to dsDNA, ssDNA, lipopolysaccharide (LPS or insulin and they did not exist in umbilical cord serum, implying that they were not natural Abs. The IgM Abs against mono-methylated lysine are present in healthy subjects but are significantly lower in SLE patients, suggesting a distinct origin of production and special physiological functions.

  3. Vinyl ether silicones

    Energy Technology Data Exchange (ETDEWEB)

    Herzig, C.; Dauth, J.; Deubzer, B.; Weis, J. [Wacker-Chemie GmbH, Burghausen (Germany)

    1995-12-01

    Siloxanes with vinyl ether groups are prepared by hydrosilylation reaction of dihydrosiloxanes with divinyl ethers in excess. Different stoichiometry, produces linear copolymers of different viscosities and double bond concentrations always with an active vinyl ether group at each chain end. Polymerisations triggered by UV light were done with mixtures of these compounds and a series of onium salts. Very fast cure is observed even with low doses at 290 nm. V.E. silicones are found to cure essentially quantitative. The comparison with other highly reactive cationic monomers revealed that compounds are among the fastest curing prepolymers in cationic chemistry.

  4. Catalytic oxidation of dimethyl ether

    Science.gov (United States)

    Zelenay, Piotr; Wu, Gang; Johnston, Christina M.; Li, Qing

    2016-05-10

    A composition for oxidizing dimethyl ether includes an alloy supported on carbon, the alloy being of platinum, ruthenium, and palladium. A process for oxidizing dimethyl ether involves exposing dimethyl ether to a carbon-supported alloy of platinum, ruthenium, and palladium under conditions sufficient to electrochemically oxidize the dimethyl ether.

  5. Solubilities of CO2 in some glycol ethers under high pressure by experimental determination and correlation☆

    Institute of Scientific and Technical Information of China (English)

    Wei Wang; Zhi Yun; Zhigang Tang; Xia Gui

    2016-01-01

    The binary vapor–liquid equilibrium data of CO2 in diethylene glycol (monomethyl, monoethyl, monobutyl, di-methyl, diethyl, dibutyl) ether were determined from 288.15 to 318.15 K at pressure up to 6 MPa based on the constant-volume method. It was found by contrast that the ether group in solvents can promote the CO2 absorp-tion, but the hydroxyl group will inhibit the CO2 absorption. Furthermore, the solubilities of CO2 showed an up-ward trend with the increasing molecular lengths of absorbents. The experimental data were also correlated with a modified Patel–Teja equation of state (PT EOS) combined with the traditional van der Waals one-fluid mixing rules and the results showed a satisfactory agreement between the model and the experimental data.

  6. Microbiology and potential applications of aerobic methane oxidation coupled to denitrification (AME-D) process: A review.

    Science.gov (United States)

    Zhu, Jing; Wang, Qian; Yuan, Mengdong; Tan, Giin-Yu Amy; Sun, Faqian; Wang, Cheng; Wu, Weixiang; Lee, Po-Heng

    2016-03-01

    Aerobic methane oxidation coupled to denitrification (AME-D) is an important link between the global methane and nitrogen cycles. This mini-review updates discoveries regarding aerobic methanotrophs and denitrifiers, as a prelude to spotlight the microbial mechanism and the potential applications of AME-D. Until recently, AME-D was thought to be accomplished by a microbial consortium where denitrifying bacteria utilize carbon intermediates, which are excreted by aerobic methanotrophs, as energy and carbon sources. Potential carbon intermediates include methanol, citrate and acetate. This mini-review presents microbial thermodynamic estimations and postulates that methanol is the ideal electron donor for denitrification, and may serve as a trophic link between methanotrophic bacteria and denitrifiers. More excitingly, new discoveries have revealed that AME-D is not only confined to the conventional synergism between methanotrophic bacteria and denitrifiers. Specifically, an obligate aerobic methanotrophic bacterium, Methylomonas denitrificans FJG1, has been demonstrated to couple partial denitrification with methane oxidation, under hypoxia conditions, releasing nitrous oxide as a terminal product. This finding not only substantially advances the understanding of AME-D mechanism, but also implies an important but unknown role of aerobic methanotrophs in global climate change through their influence on both the methane and nitrogen cycles in ecosystems. Hence, further investigation on AME-D microbiology and mechanism is essential to better understand global climate issues and to develop niche biotechnological solutions. This mini-review also presents traditional microbial techniques, such as pure cultivation and stable isotope probing, and powerful microbial techniques, such as (meta-) genomics and (meta-) transcriptomics, for deciphering linked methane oxidation and denitrification. Although AME-D has immense potential for nitrogen removal from wastewater, drinking

  7. Air Traffic Management Research at NASA Ames

    Science.gov (United States)

    Davis, Thomas J.

    2012-01-01

    The Aviation Systems Division at the NASA Ames Research Center conducts leading edge research in air traffic management concepts and technologies. This overview will present concepts and simulation results for research in traffic flow management, safe and efficient airport surface operations, super density terminal area operations, separation assurance and system wide modeling and simulation. A brief review of the ongoing air traffic management technology demonstration (ATD-1) will also be presented. A panel discussion, with Mr. Davis serving as a panelist, on air traffic research will follow the briefing.

  8. PSP Testing at NASA Ames Research Center

    Science.gov (United States)

    Bell, J. H.; Hand, L. A.; Schairer, E. T.; Mehta, R. D.; George, Michael W. (Technical Monitor)

    1997-01-01

    Pressure sensitive paints (PSPs) are now used routinely for measuring surface pressures on wind tunnel models at transonic and supersonic Mach numbers. The method utilizes a surface coating containing fluorescent or phosphorescent materials, the brightness of which varies with the local air pressure on the surface. The present paper will summarize PSP activities (in progress and planned) at the NASA Ames Research Center. One of the main accomplishments at NASA Ames has been the development of a PSP measurement system that is production testing capable. This system has been integrated successfully into the large-scale wind tunnel facilities at Ames. There are several problems related to PSP testing which are unique to large-scale wind tunnel testing. The hardware is often difficult to set-up and must operate under harsh conditions (e.g. high pressures and low temperatures). The data acquisition and reduction times need to be kept to a minimum so that the overall wind tunnel productivity is not compromised. The pressure sensitive paints needs to be very robust; the paints must readily adhere to different surfaces with varying geometries and remain functional for long running times. The paint must have well understood, and preferably minimal, temperature sensitivity since fine control of the tunnel temperature is not easily achievable in the larger wind tunnels. In an effort to improve the overall accuracy of the PSP technique, we are currently evaluating some referenced pressure sensitive paints which contain a pressure- independent luminophor in addition to the one which is affected by the surface pressure. The two luminophors are chosen so that their emission wavelengths are somewhat different. Then by taking two 'wind-on' images with either two cameras (with different filters) or one camera with a rotating filter system, the need for 'wind-off' images can be eliminated. The ratio of the two wind-on images accounts for nonuniform lighting and model motion problems

  9. Modification of chitosan with monomethyl fumaric acid in an ionic liquid solution.

    Science.gov (United States)

    Wang, Zhaodong; Zheng, Liuchun; Li, Chuncheng; Zhang, Dong; Xiao, Yaonan; Guan, Guohu; Zhu, Wenxiang

    2015-03-01

    Antibacterial and antioxidant monomethyl fumaric acid (MFA) was selected to modify chitosan, using aqueous solution of an ionic liquid as a homogeneous and green reaction media. The chemical structures of resulting polymers were systematically characterized by (1)H NMR, diffusion ordered spectroscopy, solid (13)C NMR and wide-angle X-ray diffraction. The results show that two kinds of MFA modified chitosan materials with totally different chemical structures have been synthesized. One product was a MF-chitosan salt composed of chitosan cation and MFA anion, which was obtained with the mediation of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide. The other one synthesized with the mediation of EDC was a MF-chitosan amide in which MFA and chitosan are covalently attached. Solubility of chitosan has been improved, and MF-chitosan salt can be readily dissolved in water. The antioxidant activity has been enhanced with the introduction of MFA, irrespective of the chemical structure.

  10. Developing A New Sampling and Analysis Method for Hydrazine and Monomethyl Hydrazine

    Science.gov (United States)

    Allen, John R.

    2002-01-01

    Solid phase microextraction (SPME) will be used to develop a method for detecting monomethyl hydrazine (MMH) and hydrazine (Hz). A derivatizing agent, pentafluorobenzoyl chloride (PFBCl), is known to react readily with MMH and Hz. The SPME fiber can either be coated with PFBCl and introduced into a gaseous stream containing MMH, or PFBCl and MMH can react first in a syringe barrel and after a short equilibration period a SPME is used to sample the resulting solution. These methods were optimized and compared. Because Hz and MMH can degrade the SPME, letting the reaction occur first gave better results. Only MMH could be detected using either of these methods. Future research will concentrate on constructing calibration curves and determining the detection limit.

  11. Structural characterization of aqueous solution poly(oligo(ethylene oxide) monomethyl methacrylate)-grafted silica nanoparticles.

    Science.gov (United States)

    Lorenzo, Arnaldo T; Ponnapati, Ramakrishna; Chatterjee, Tirtha; Krishnamoorti, Ramanan

    2016-01-01

    The structure of aqueous dispersions of poly(oligo(ethylene oxide) monomethyl methacrylate)-grafted silica nanoparticles was characterized using contrast variation small-angle neutron scattering studies. Modeling the low hybrid concentration dispersion scattering data using a fuzzy sphere and a polydisperse core-shell model, demonstrated that the polymer chains are highly swollen in the dispersions as compared to the dimensions of the free polymer chains in dilute solution. At higher hybrid concentrations, the dispersions were well described using a Percus-Yevick approximation to describe the structure factor. These structural characterization tools are excellent starting points for effective molecular level descriptors of dewetting and macroscopic phase transitions for polymer tethered hybrid nanoparticle systems.

  12. Developing A New Sampling and Analysis Method for Hydrazine and Monomethyl Hydrazine

    Science.gov (United States)

    Allen, John R.

    2002-01-01

    Solid phase microextraction (SPME) will be used to develop a method for detecting monomethyl hydrazine (MMH) and hydrazine (Hz). A derivatizing agent, pentafluorobenzoyl chloride (PFBCl), is known to react readily with MMH and Hz. The SPME fiber can either be coated with PFBCl and introduced into a gaseous stream containing MMH, or PFBCl and MMH can react first in a syringe barrel and after a short equilibration period a SPME is used to sample the resulting solution. These methods were optimized and compared. Because Hz and MMH can degrade the SPME, letting the reaction occur first gave better results. Only MMH could be detected using either of these methods. Future research will concentrate on constructing calibration curves and determining the detection limit.

  13. Center Overview and UAV Highlights at NASA Ames Research Center

    Science.gov (United States)

    Feng, Deborah; Yan, Jerry Chi Yiu

    2017-01-01

    The PowerPoint presentation gives an overview of NASA Ames Research Center and its core competencies, as well as some of the highlights of Unmanned Aerial Vehicle (UAV) and Unmanned Aircraft Systems (UAS) accomplishments and innovations by researchers at Ames.

  14. Radiological survey support activities for the decommissioning of the Ames Laboratory Research Reactor Facility, Ames, Iowa

    Energy Technology Data Exchange (ETDEWEB)

    Wynveen, R.A.; Smith, W.H.; Sholeen, C.M.; Justus, A.L.; Flynn, K.F.

    1984-09-01

    At the request of the Engineering Support Division of the US Department of Energy-Chicago Operations Office and in accordance with the programmatic overview/certification responsibilities of the Department of Energy Environmental and Safety Engineering Division, the Argonne National Laboratory Radiological Survey Group conducted a series of radiological measurements and tests at the Ames Laboratory Research Reactor located in Ames, Iowa. These measurements and tests were conducted during 1980 and 1981 while the reactor building was being decontaminated and decommissioned for the purpose of returning the building to general use. The results of these evaluations are included in this report. Although the surface contamination within the reactor building could presumably be reduced to negligible levels, the potential for airborne contamination from tritiated water vapor remains. This vapor emmanates from contamination within the concrete of the building and should be monitored until such time as it is reduced to background levels. 2 references, 8 figures, 6 tables.

  15. SYNTHESIS AND PROPERTIES OF SULFONATED POLY(ARYLENE ETHER) CONTAINING TRIPHENYL METHANE MOIETIES FROM ISOCYNATE MASKED BISPHENOL

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel sulfonated poly(arylene ether) containing triphenylmethane moieties was synthesized by the sulfonation of a designed parent polymer using chlorosulfonic acid as sulfonation agent. The sulfonation took place at the para position of the pendant phenyl rings because of the specially designed parent polymer. The position and degree of sulfonation were characterized by 1H-NMR and elemental analysis. The sulfonated polymers are highly soluble in common organic solvents, such as dimethylsulfoxide, N,N'-dimethylacetamide, dimethylformamide, ethylene glycol monomethyl ether, and can be readily cast into tough and smooth films from solutions. The films showed good thermal and hydrolysis stabilities. Moreover, Fenton's reagent test revealed that the films exhibited superior stability to oxidation. The proton conductivities of the films were comparable with Nation 117 under same conditions. The membrane electrode assembly (MEA) prepared with the asmade film (706 EW, 100 μm dry thickness) shows better cell performance than Nation 115-MEA in the whole current density range.

  16. Studies of Anomalous Microwave Emission (AME) with the SKA

    CERN Document Server

    Dickinson, Clive; Beswick, Robert J; Casassus, Simon; Cleary, Kieran; Draine, Bruce T; Genova-Santos, Ricardo; Grainge, Keith; Hoang, Thiem C; Lazarian, Alex; Murphy, Eric J; Paladini, Roberta; Peel, Michael W; Perrott, Yvette; Rubino-Martin, Jose-Alberto; Scaife, Anna; Tibbs, Chris T; Verstraete, Laurent; Vidal, Matias; Watson, Robert A; Ysard, Nathalie

    2014-01-01

    In this chapter, we will outline the scientific motivation for studying Anomalous Microwave Emission (AME) with the SKA. AME is thought to be due to electric dipole radiation from small spinning dust grains, although thermal fluctuations of magnetic dust grains may also contribute. Studies of this mysterious component would shed light on the emission mechanism, which then opens up a new window onto the interstellar medium (ISM). AME is emitted mostly in the frequency range $\\sim 10$--100\\,GHz, and thus the SKA has the potential of measuring the low frequency side of the AME spectrum, particularly in band 5. Science targets include dense molecular clouds in the Milky Way, as well as extragalactic sources. We also discuss the possibility of detecting rotational line emission from Poly-cyclic Aromatic Hydrocarbons (PAHs), which could be the main carriers of AME. Detecting PAH lines of a given spacing would allow for a definitive identification of specific PAH species.

  17. Adipose tissue monomethyl branched chain fatty acids and insulin sensitivity: effects of obesity and weight loss

    Science.gov (United States)

    Su, Xiong; Magkos, Faidon; Zhou, Dequan; Eagon, J. Christopher; Fabbrini, Elisa; Okunade, Adewole L.; Klein, Samuel

    2014-01-01

    Objective An increase in circulating branched-chain amino acids (BCAA) is associated with insulin resistance. Adipose tissue is a potentially important site for BCAA metabolism. We evaluated whether monomethyl branched chain fatty acids (mmBCFA) in adipose tissue, which are likely derived from BCAA catabolism, are associated with insulin sensitivity. Design and Methods Insulin-stimulated glucose disposal was determined by using the hyperinsulinemic-euglycemic clamp procedure with stable isotope glucose tracer infusion, in 9 lean and 9 obese subjects, and in a separate group of 9 obese subjects before and 1 year after Roux-en-Y gastric bypass (RYGB) surgery (38% weight loss). Adipose tissue mmBCFA content was measured in tissue biopsies taken in the basal state. Results Total adipose tissue mmBCFA content was ~30% lower in obese than lean subjects (P = 0.02), and increased by ~65% after weight loss in the RYGB group (P = 0.01). Adipose tissue mmBCFA content correlated positively with skeletal muscle insulin sensitivity (R2 = 35%, P = 0.01, n = 18). Conclusions These results demonstrate a novel association between adipose tissue mmBCFA content and obesity-related insulin resistance. Additional studies are needed to determine whether the association between adipose tissue mmBCFA and muscle insulin sensitivity is causal or a simple association. PMID:25328153

  18. Effect of pravastatin on responsiveness to N-monomethyl-L-arginine in patients with hypercholesterolaemia.

    Science.gov (United States)

    Bayerle-Eder, Michaela; Fuchsjäger-Mayrl, Gabriele; Sieder, Anna; Polska, Elzbieta; Roden, Michael; Stulnig, Thomas; Bischof, Martin G; Waldhäusl, Werner; Schmetterer, Leopold; Wolzt, Michael

    2002-01-01

    Improvement of endothelial function in hypercholesterolaemia is attributed to lipid lowering and to pleiotropic effects of statin therapy. We investigated whether responsiveness to inhibition of constitutive NO formation with N-monomethyl-L-arginine (L-NMMA) is improved after 7 and 28 days of pravastatin. Twelve female and four male subjects with mild or moderate primary hypercholesterolaemia were randomized to pravastatin (20 mg per oral (p.o.) n=8) or placebo (n=8) in a double blind parallel group design. Vascular responsiveness was studied by intravenous bolus infusions of L-NMMA (cumulative doses of 3 and 6 mg/kg). Mean arterial blood pressure (MAP) and pulse rate (PR) were measured noninvasively, pulsatile choroidal blood flow was assessed with laser interferometric measurement of fundus pulsation amplitudes (FPA) and renal plasma flow (RPF) was measured by the PAH clearance method. Pravastatin lowered plasma cholesterol levels by 16 and 24% after 7 and 28 days of treatment, respectively (P<0.01). L-NMMA caused comparable changes in MAP, PR and RPF between groups. L-NMMA reduced FPA to a similar extent in both groups before and after 7 days of treatment, but the response to L-NMMA was significantly enhanced after 28 days of pravastatin (21%; P<0.001 vs baseline) and greater than after placebo (15%; P<0.01 vs pravastatin). Pravastatin enhances responsiveness to L-NMMA in the ocular microvasculature. Improved responsiveness is associated with changes in total cholesterol levels.

  19. Dimethyl Mercury in Seawater: a Potential Source of Monomethyl Mercury in Fog

    Science.gov (United States)

    Coale, K. H.; Heim, W. A.; Olson, A.; Chiswell, H.; Byington, A.; Newman, A.; Bonnema, A.; Johnson, M.; Fernandez, D.; Weiss-Penzias, P. S.; Parker, C.

    2015-12-01

    Our collaborative studies show that maritime advective fog transports monomethyl mercury (MMHg) from the oceans to land where terrestrial biota accumulate this neurotoxin to high levels. To date the source of MMHg and the mechanism of this cycling remain unknown. We show that the rate of gaseous evasion of dimethyl mercury (DMHg) is fairly large. Vertical gradients of dimethyl mercury (DMHg) from cyclonic eddies in the California Current indicate an evasive loss of this compound of over 10 pmol m-2 d-1 from these and other upwelling systems. Previous experiments, however, indicated that the rate of photolytic demethylation of DMHg to MMHg is extremely slow in seawater. In this study we performed photodemethylation experiments in both natural seawater and seawater acidified to pH = 5 (the pH of fog). These results confirm the low rates of photodemethylation of DMHg previously observed, yet also show that photodemethylation is a significant factor in the demethylation of DMHg at low pH and thus a potential source of MMHg in fog. These findings suggest photodemethylation may occur atmospherically, and may explain both the high concentrations of MMHg found in fog, and the difference in concentrations of MMHg found in fog water vs rainwater.

  20. Environmental monitoring at Ames Laboratory: Calendar year 1975

    Energy Technology Data Exchange (ETDEWEB)

    Voss, M.D.

    1976-04-01

    This is an annual report summarizing the effluent and environmental monitoring program at the Ames Laboratory of the United States Energy Research and Development Administration. An inventory of the radioactive materials and certain chemicals released to the environment is included. A summary of the radioactivity found in the environment is presented. An estimate of the radiation dose to the public resulting from the operations of the Ames Laboratory is stated. (auth)

  1. Ames Laboratory integrated safety management self-assessment report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-10-01

    The implementation of Integrated Safety Management (ISM) at Ames Laboratory began with the signing of the ISM Implementation Charter on February 24, 1997 (see Appendix A). The first step toward implementation of ISM at Ames Laboratory is the performance of a Self-Assessment (SA). In preparation for the SA, a workshop on ISM was provided to the Laboratory`s Environment, Safety, and Health (ES&H) Coordinators, Safety Review Committee members, and the Environment, Safety, Health and Assurance (ESH&A) staff. In addition, a briefing was given to the Laboratory`s Executive Council and Program Directors. Next, an SA Team was organized. The Team was composed of four Ames Laboratory and four Department of Energy-Chicago Operations Office (DOE-CH) staff members. The purpose of this SA was to determine the current status of ES&H management within Ames Laboratory, as well as to identify areas which need to be improved during ISM implementation. The SA was conducted by reviewing documents, interviewing Ames Laboratory management and staff, and performing walkthroughs of Laboratory areas. At the conclusion of this SA, Ames Laboratory management was briefed on the strengths, weaknesses, and the areas of improvement which will assist in the implementation of ISM.

  2. Direct Dimethyl Ether Synthesis

    Institute of Scientific and Technical Information of China (English)

    Takashi Ogawa; Norio Inoue; Tutomu Shikada; Yotaro Ohno

    2003-01-01

    Dimethyl ether (DME) is a clean and economical alternative fuel which can be produced from natural gas through synthesis gas. The properties of DME are very similar to those of LP gas. DME can be used for various fields as a fuel such as power generation, transportation, home heating and cooking,etc. It contains no sulfur or nitrogen. It is not corrosive to any metal and not harmful to human body. An innovative process of direct synthesis of DME from synthesis gas has been developed. Newly developed catalyst in a slurry phase reactor gave a high conversion and high selectivity of DME production. One and half year pilot scale plant (5 tons per day) testing, which was supported by METI, had successfully finished with about 400 tons DME production.

  3. Mutation in Mg-Protoporphyrin IX Monomethyl Ester Cyclase Decreases Photosynthesis Capacity in Rice

    Science.gov (United States)

    Wang, Xuexia; Huang, Rongfeng; Quan, Ruidang

    2017-01-01

    In photosynthesis, the pigments chlorophyll a/b absorb light energy to convert to chemical energy in chloroplasts. Though most enzymes of chlorophyll biosynthesis from glutamyl-tRNA to chlorophyll a/b have been identified, the exact composition and regulation of the multimeric enzyme Mg-protoporphyrin IX monomethyl ester cyclase (MPEC) is largely unknown. In this study, we isolated a rice pale-green leaf mutant m167 with yellow-green leaf phenotype across the whole lifespan. Chlorophyll content decreases 43–51% and the granal stacks of chloroplasts becomes thinner in m167. Chlorophyll fluorescence parameters, including Fv/Fm (the maximum quantum efficiency of PSII) and quantum yield of PSII (Y(II)), were lower in m167 than those in wild type plants (WT), and photosynthesis rate decreases 40% in leaves of m167 mutant compared with WT plants, which lead to yield reduction in m167. Genetic analysis revealed that yellow-green leaf phenotype of m167 is controlled by a single recessive genetic locus. By positional cloning, a single mutated locus, G286A (Alanine 96 to Threonine in protein), was found in the coding sequence of LOC_Os01g17170 (Rice Copper Response Defect 1, OsCRD1), encoding a putative subunit of MPEC. Expression profile analysis demonstrated that OsCRD1 is mainly expressed in green tissues of rice. Sequence alignment analysis of CRD1 indicated that Alanine 96 is very conserved in all green plants and photosynthetic bacteria. OsCRD1 protein mainly locates in chloroplast and the point mutation A96T in OsCRD1 does not change its location. Therefore, Alanine96 of OsCRD1 might be fundamental for MPEC activity, mutation of which leads to deficiency in chlorophyll biosynthesis and chloroplast development and decreases photosynthetic capacity in rice. PMID:28129387

  4. PMARC - PANEL METHOD AMES RESEARCH CENTER

    Science.gov (United States)

    Ashby, D. L.

    1994-01-01

    Panel methods are moderate cost tools for solving a wide range of engineering problems. PMARC (Panel Method Ames Research Center) is a potential flow panel code that numerically predicts flow fields around complex three-dimensional geometries. PMARC's predecessor was a panel code named VSAERO which was developed for NASA by Analytical Methods, Inc. PMARC is a new program with many additional subroutines and a well-documented code suitable for powered-lift aerodynamic predictions. The program's open architecture facilitates modifications or additions of new features. Another improvement is the adjustable size code which allows for an optimum match between the computer hardware available to the user and the size of the problem being solved. PMARC can be resized (the maximum number of panels can be changed) in a matter of minutes. Several other state-of-the-art PMARC features include internal flow modeling for ducts and wind tunnel test sections, simple jet plume modeling essential for the analysis and design of powered-lift aircraft, and a time-stepping wake model which allows the study of both steady and unsteady motions. PMARC is a low-order panel method, which means the singularities are distributed with constant strength over each panel. In many cases low-order methods can provide nearly the same accuracy as higher order methods (where the singularities are allowed to vary linearly or quadratically over each panel). Low-order methods have the advantage of a shorter computation time and do not require exact matching between panels. The flow problem is solved by assuming that the body is at rest in a moving flow field. The body is modeled as a closed surface which divides space into two regions -- one region contains the flow field of interest and the other contains a fictitious flow. External flow problems, such as a wing in a uniform stream, have the external region as the flow field of interest and the internal flow as the fictitious flow. This arrangement is

  5. Solvent-Induced Crystallization of Poly(ether ether ketone)

    OpenAIRE

    McPeak, Jennifer Lynne

    1999-01-01

    The purpose of this study was learn how the diffusion, swelling, and crystallization processes are coupled during solvent-induced crystallization of poly(ether ether ketone) (PEEK). Unoriented amorphous PEEK films were immersed in aprotic organic liquids at ambient temperature and bulk properties or characteristics were monitored as a function of immersion time. The sorption behavior, Tg and Tm° suppression, crystallinity, and dynamic mechanical response were correlated as a function of sol...

  6. Glyceryl guaiacol ether – review

    OpenAIRE

    Massone, Flávio; Universidade Estadual Paulista; Luna, Stélio Pacca Loureiro; Universidade Estadual Paulista; Castro, Gladys Bastos; Universidade Estadual Paulista

    1996-01-01

    The history, physical and chemical properties, pharmacodynamics, pharmacokinetics, adverse effects, toxicity, clinical use in wild and domestic species and drug interactions with glyceryl guaiacol ether, an a-glyceryt ether, is presented. Guaiphenesin produces muscle relaxation without affecting diaphragmatic function. Besides muscle relaxation, the drug produces hypocholesterolemia, hypouricemia and has antitussive and expectorant actions, among others. It is a safe agent, but can produce th...

  7. Rearrangements of Cycloalkenyl Aryl Ethers

    Directory of Open Access Journals (Sweden)

    Mercedesz Törincsi

    2016-04-01

    Full Text Available Rearrangement reactions of cycloalkenyl phenol and naphthyl ethers and the acid-catalyzed cyclization of the resulting product were investigated. Claisen rearrangement afforded 2-substituted phenol and naphthol derivatives. Combined Claisen and Cope rearrangement resulted in the formation of 4-substituted phenol and naphthol derivatives. In the case of cycloocthylphenyl ether the consecutive Claisen and Cope rearrangements were followed by an alkyl migration. The mechanism of this novel rearrangement reaction is also discussed.

  8. Ether: Bitcoin's competitor or ally?

    OpenAIRE

    Bouoiyour, Jamal; Selmi, Refk

    2017-01-01

    Although Bitcoin has long been dominant in the crypto scene, it is certainly not alone. Ether is another cryptocurrency related project that has attracted an intensive attention because of its additional features. This study seeks to test whether these cryptocurrencies differ in terms of their volatile and speculative behaviors, hedge, safe haven and risk diversification properties. Using different econometric techniques, we show that a) Bitcoin and Ether are volatile and relatively more resp...

  9. The histone H4 lysine 20 monomethyl mark, set by PR-Set7 and stabilized by L(3mbt, is necessary for proper interphase chromatin organization.

    Directory of Open Access Journals (Sweden)

    Ayako Sakaguchi

    Full Text Available Drosophila PR-Set7 or SET8 is a histone methyltransferase that specifically monomethylates histone H4 lysine 20 (H4K20. L(3MBT has been identified as a reader of methylated H4K20. It contains several conserved domains including three MBT repeats binding mono- and dimethylated H4K20 peptides. We find that the depletion of PR-Set7 blocks de novo H4K20me1 resulting in the immediate activation of the DNA damage checkpoint, an increase in the size of interphase nuclei, and drastic reduction of cell viability. L(3mbt on the other hand stabilizes the monomethyl mark, as L(3mbt-depleted S2 cells show a reduction of more than 60% of bulk monomethylated H4K20 (H4K20me1 while viability is barely affected. Ploidy and basic chromatin structure show only small changes in PR-Set7-depleted cells, but higher order interphase chromatin organization is significantly affected presumably resulting in the activation of the DNA damage checkpoint. In the absence of any other known functions of PR-Set7, the setting of the de novo monomethyl mark appears essential for cell viability in the presence or absence of the DNA damage checkpoint, but once newly assembled chromatin is established the monomethyl mark, protected by L(3mbt, is dispensable.

  10. Sources of inorganic and monomethyl mercury to high and sub Arctic marine ecosystems

    Science.gov (United States)

    Kirk, Jane Liza

    Monomethyl mercury (MMHg), a toxic and bioaccumulative form of Hg, is present in some Canadian high and sub Arctic marine mammals at concentrations high enough to pose health risks to Northern peoples using these animals as food. To quantify potentially large sources of Hg to Arctic marine ecosystems, we examined several aspects of Hg cycling in the Canadian Arctic Archipelago (CAA) and Hudson Bay. Firstly, we quantified net Hg inputs to Hudson Bay from atmospheric Hg depletion events (AMDEs). During AMDEs, gaseous elemental Hg(0) (GEM), which is present in the Arctic atmosphere at global background concentrations, is oxidized to inorganic Hg(II) species that deposit to snowpacks. By simultaneously monitoring Hg in the atmosphere and in snowpacks of western Hudson Bay, we demonstrated that most of the Hg(II) deposited during AMDEs is rapidly (photo)reduced and emitted to the atmosphere. Secondly, we examined Hg speciation in marine waters of the CAA and Hudson Bay. We found high concentrations of MMHg and dimethyl Hg (DMHg; a toxic, gaseous form of Hg) in deep marine waters, where they are likely produced from Hg(II). Arctic marine waters were also found to be a substantial source of DMHg and GEM to the atmosphere. Thirdly, we quantified Hg exports to Hudson Bay from two major rivers, the Nelson and the Churchill, which have been altered for hydroelectric power production. When landscapes are inundated during river diversion or reservoir creation, microbial production of MMHg is stimulated in flooded soils. Newly produced MMHg can then be exported to downstream waterbodies. We found that annual inputs of total Hg (THg; includes both Hg(II) and MMHg) to Hudson Bay from combined Nelson and Churchill River discharge were comparable to inputs from AMDEs. MMHg inputs from river discharge are, however, ˜13 times greater than those from annual snowmelt of Hudson Bay snowpacks. Finally, although combined river and AMDE Hg inputs may account for a large portion of the THg

  11. Building Climate Resilience at NASA Ames Research Center

    Science.gov (United States)

    Iraci, L. T.; Mueller, C.; Podolske, J. R.; Milesi, C.

    2016-12-01

    NASA Ames Research Center, located at the southern end of the San Francisco Bay (SFB) estuary, has identified three primary vulnerabilities to changes in climate. The Ames Climate Adaptation Science Investigator (CASI) workgroup has studied each of these challenges to operations and the potential exposure of infrastructure and employees to an increased frequency of hazards. Sea level rise inundation scenarios for the SFB Area generally refer to projected scenarios in mean sea level rather than changes in extreme tides that could occur during future storm conditions. In the summer of 2014, high resolution 3-D mapping of the low-lying portion of Ames was performed. Those data are integrated with improved sea level inundation scenarios to identify the buildings, basements and drainage systems potentially affected. We will also identify the impacts of sea level and storm surge effects on transportation to and from the Center. This information will help Center management develop future master plans. Climate change will also lead to changes in temperature, storm frequency and intensity. These changes have potential impacts on localized floods and ecosystems, as well as on electricity and water availability. Over the coming decades, these changes will be imposed on top of ongoing land use and land cover changes, especially those deriving from continued urbanization and increase in impervious surface areas. These coupled changes have the potential to create a series of cascading impacts on ecosystems, including changes in primary productivity and disturbance of hydrological properties and increased flood risk. The majority of the electricity used at Ames is supplied by hydroelectric dams, which will be influenced by reductions in precipitation or changes in the timing or phase of precipitation which reduces snow pack. Coupled with increased demand for summertime air conditioning and other cooling needs, NASA Ames is at risk for electricity shortfalls. To assess the

  12. Luminescent Lariat Aza-Crown Ether

    Directory of Open Access Journals (Sweden)

    Burkhard König

    2010-03-01

    Full Text Available Lariat ethers are interesting recognition motifs in supramolecular chemistry. The synthesis of a luminescent lariat ether with triglycol chain by azide–alkyne (Huisgen cycloaddition is presented.

  13. Exogenous ether lipids predominantly target mitochondria.

    Directory of Open Access Journals (Sweden)

    Lars Kuerschner

    Full Text Available Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria in ether lipid metabolism and intracellular ether lipid trafficking.

  14. Fisher Ames and Political Judgment: Reason, Passion, and Vehement Style in the Jay Treaty Speech.

    Science.gov (United States)

    Farrell, James M.

    1990-01-01

    Analyzes Fisher Ames' fiery speech of 1796 on the Jay Treaty. Demonstrates the influence of Scottish enlightenment thinkers (particularly in moral sense philosophy and faculty psychology) on Ames and his rhetoric. Demonstrates how Ames made a compelling case to shift the standard of political judgment from reason to passion. (SR)

  15. Developing a New Sampling And Analysis Method For Hydrazine And Monomethyl Hydrazine: Using a Derivatizing Agent With Solid Phase Microextraction

    Science.gov (United States)

    Allen, John

    2001-01-01

    Solid phase microextraction (SPME) will be used to develop a method for detecting monomethyl hydrazine (MMH) and hydrazine (Hz). A derivatizing agent, pentafluorobenzoyl chloride (PFBCI), is known to react readily with MMH and Hz. The SPME fiber can either be coated with PFBCl and introduced into a gaseous stream containing MMH, or PFBCl and MMH can react first in a syringe barrel and after a short equilibration period a SPME is used to sample the resulting solution. These methods were optimized and compared. Because Hz and MMH can degrade the SPME, letting the reaction occur first gave better results. Only MMH could be detected using either of these methods. Future research will concentrate on constructing calibration curves and determining the detection limit.

  16. Identification of the chlE gene encoding oxygen-independent Mg-protoporphyrin IX monomethyl ester cyclase in cyanobacteria.

    Science.gov (United States)

    Yamanashi, Kaori; Minamizaki, Kei; Fujita, Yuichi

    2015-08-07

    The fifth ring (E-ring) of chlorophyll (Chl) a is produced by Mg-protoporphyrin IX monomethyl ester (MPE) cyclase. There are two evolutionarily unrelated MPE cyclases: oxygen-independent (BchE) and oxygen-dependent (ChlA/AcsF) MPE cyclases. Although ChlA is the sole MPE cyclase in Synechocystis PCC 6803, it is yet unclear whether BchE exists in cyanobacteria. A BLAST search suggests that only few cyanobacteria possess bchE. Here, we report that two bchE candidate genes from Cyanothece strains PCC 7425 and PCC 7822 restore the photosynthetic growth and bacteriochlorophyll production in a bchE-lacking mutant of Rhodobacter capsulatus. We termed these cyanobacterial bchE orthologs "chlE."

  17. Developing a New Sampling And Analysis Method For Hydrazine And Monomethyl Hydrazine: Using a Derivatizing Agent With Solid Phase Microextraction

    Science.gov (United States)

    Allen, John

    2001-01-01

    Solid phase microextraction (SPME) will be used to develop a method for detecting monomethyl hydrazine (MMH) and hydrazine (Hz). A derivatizing agent, pentafluorobenzoyl chloride (PFBCI), is known to react readily with MMH and Hz. The SPME fiber can either be coated with PFBCl and introduced into a gaseous stream containing MMH, or PFBCl and MMH can react first in a syringe barrel and after a short equilibration period a SPME is used to sample the resulting solution. These methods were optimized and compared. Because Hz and MMH can degrade the SPME, letting the reaction occur first gave better results. Only MMH could be detected using either of these methods. Future research will concentrate on constructing calibration curves and determining the detection limit.

  18. Developing questionnaires for educational research: AMEE Guide No. 87.

    Science.gov (United States)

    Artino, Anthony R; La Rochelle, Jeffrey S; Dezee, Kent J; Gehlbach, Hunter

    2014-06-01

    In this AMEE Guide, we consider the design and development of self-administered surveys, commonly called questionnaires. Questionnaires are widely employed in medical education research. Unfortunately, the processes used to develop such questionnaires vary in quality and lack consistent, rigorous standards. Consequently, the quality of the questionnaires used in medical education research is highly variable. To address this problem, this AMEE Guide presents a systematic, seven-step process for designing high-quality questionnaires, with particular emphasis on developing survey scales. These seven steps do not address all aspects of survey design, nor do they represent the only way to develop a high-quality questionnaire. Instead, these steps synthesize multiple survey design techniques and organize them into a cohesive process for questionnaire developers of all levels. Addressing each of these steps systematically will improve the probabilities that survey designers will accurately measure what they intend to measure.

  19. Characterization of local vascular effects of the nitric oxide inhibitor NG-monomethyl-L-arginine on dorsal hand veins.

    Science.gov (United States)

    Schindler, Christoph; Leuschner, Sven; Schwanebeck, Uta; Kirch, Wilhelm

    2012-06-01

    Infusion of NG-monomethyl-L-arginine (L-NMMA; 6.4 µmol/min) into hand veins can cause a 20% increase in vein size in specific subjects. This study explored potential underlying mechanisms in healthy male participants. Ten healthy male participants received in phenylephrine (PE)-preconstricted veins a dose-response curve (DRC) to L-NMMA (0.2-6.4 µmol/min) without and with coinfusion of the endothelium-dependent dilator histamine, a DRC to L-arginine with and without coinfusion of L-NMMA, a DRC to NG-monomethyl-D-arginine (D-NMMA), and a DRC to L-NMMA in prostaglandin F(2α)-(PGF(2α))-preconstricted veins. Participants were classified as L-NMMA responders (R) and nonresponders (NR). Infusion of L-NMMA resulted in a maximum venodilation of 38% ± 11% (R) versus 10% ± 5% (NR; P = .005). In PGF(2α)-preconstricted veins, L-NMMA caused venodilation to 26% ± 34% (NS) in responders. Results suggest that endothelial nitric oxide synthase-mediated formation of nitric oxide (NO) from L-NMMA in doses >3.2 µmol/min and continuous PE-induced α-adrenergic stimulation resulting in release of very small amounts of NO from L-NMMA contribute to the observed L-NMMA-induced increase in vein size. Venous reactivity to L-NMMA resulting in a phenotype as R or NR is most likely genetically predetermined, which requires further study.

  20. NASA Ames and Future of Space Exploration, Science, and Aeronautics

    Science.gov (United States)

    Cohen, Jacob

    2015-01-01

    Pushing the frontiers of aeronautics and space exploration presents multiple challenges. NASA Ames Research Center is at the forefront of tackling these issues, conducting cutting edge research in the fields of air traffic management, entry systems, advanced information technology, intelligent human and robotic systems, astrobiology, aeronautics, space, earth and life sciences and small satellites. Knowledge gained from this research helps ensure the success of NASA's missions, leading us closer to a world that was only imagined as science fiction just decades ago.

  1. Insulin sensitivity in long-living Ames dwarf mice

    OpenAIRE

    Wiesenborn, Denise S.; Ayala, Julio E.; King, Emily; Masternak, Michal M.

    2014-01-01

    Long-living Ames dwarf mice (df/df) characterized by growth hormone (GH) deficiency are widely used in aging research because of their 40–60 % lifespan extension compared to normal (N) littermates. Importantly, these mice not only live longer but are also protected from age-related diseases including insulin resistance. Several studies demonstrate that df/df mice have enhanced insulin signaling in different insulin-sensitive tissues and suggest that this is a mechanism for extended lifespan. ...

  2. Ames Laboratory Site Environmental Report, Calendar year 1991

    Energy Technology Data Exchange (ETDEWEB)

    Mathison, L.

    1991-12-31

    The summarized data and conclusions from the Ames Laboratory environmental monitoring program are presented in this Annual Site Environmental Report. This program is a working requirement of Department of Energy (DOE) Order 5484.1, ``Environmental Protection, Safety, and Health Protection Information Reporting Requirements`` and Order 5400.1, ``General Environmental Protection Program.`` Ames Laboratory is located on the campus of Iowa State University (ISU) and occupies several buildings owned by the DOE. The Laboratory also leases space in ISU-owned buildings. Laboratory research activities involve less than ten percent of the total chemical use and one percent of the radioisotope use on the ISU campus. Ames Laboratory is responsible for a small chemical burial site, located on ISU property. The site was used for the disposal of chemical and metal slags from thorium and uranium production. Samples of water from existing test wells and upstream and downstream sites on the nearby Squaw Creek show no detectable migration of the contents of the burial site. A Site Assessment plan submitted to the State of Iowa Department of Natural Resources (DNR) was approved. A Remedial Investigation/Feasibility Study work plan has been completed for additional studies at the site. This has been reviewed and approved by the DOE Chicago Field Office and the DNR. A National Environmental Policy Act (NEPA) review of the site resulted in a categorical exclusion finding which has been approved by the DOE. Ames Laboratory has an area contaminated by diesel fuel at the location of a storage tank which was removed in 1970. Soil corings and groundwater have been analyzed for contamination and an assessment written. Pollution awareness and waste minimization programs and plans were implemented in 1990. Included in this effort was the implementation of a waste white paper and green computer paper recycling program.

  3. Ames Coronagraph Experiment: Enabling Missions to Directly Image Exoplanets

    Science.gov (United States)

    Belikov, Ruslan

    2014-01-01

    Technology to find biomarkers and life on other worlds is rapidly maturing. If there is a habitable planet around the nearest star, we may be able to detect it this decade with a small satellite mission. In the 2030 decade, we will likely know if there is life in our Galactic neighborhood (1000 nearest stars). The Ames Coronagraph Experiment is developing coronagraphic technologies to enable such missions.

  4. Environmental monitoring at Ames Laboratory: calendar year 1980

    Energy Technology Data Exchange (ETDEWEB)

    Voss, M.D.

    1981-04-01

    The results and conclusions from the Ames Laboratory environmental monitoring programs for the Ames Laboratory Research Reactor (ALRR) and other Laboratory facilities are presented. The major areas of radiological monitoring were ALRR effluent air, environmental air, effluent water and environmental water. A summary of the radioactivity found in the environment is presented. The ALRR ceased operation on December 1, 1977. Decommissioning activities began January 3, 1978, and are scheduled for completion October 1, 1981. Analysis of air samples collected at the ALRR on-site station showed no radioactivity that could be attributed to ALRR operations. The radiosotope of significance in the ALRR stack effluent was tritium (H-3). The yearly individual dose from H-3 at the exclusion fence was estimated to be 0.016 mRem and the estimated dose to the entire population within an 80 Km (50 mile) radius of the ALRR was 26.6 man-Rem. These values are 0.0032% and 0.026%, respectively, of the doses derived from the concentration guides. On September 1, 1978, the ALRR site was connected to the City of Ames sanitary sewage system. All liquids (except building foundation and roof water) from the ALRR complex are now discharged to the sewage system negating the requirement for monitoring chemical constituents of effluent and environmental waters. In the radioactive liquid waste released to the City of Ames sewage system from the ALRR complex, H-3 was the predominant isotope. After dilution with other waste water from the ALRR complex, the potential dose was not more than 0.68% of the dose derived from the concentration guide. Building foundation and roof water are discharged to a drainage gulch on site.

  5. Air Traffic Management Research at NASA Ames Research Center

    Science.gov (United States)

    Lee, Katharine

    2005-01-01

    Since the late 1980's, NASA Ames researchers have been investigating ways to improve the air transportation system through the development of decision support automation. These software advances, such as the Center-TRACON Automation System (eTAS) have been developed with teams of engineers, software developers, human factors experts, and air traffic controllers; some ASA Ames decision support tools are currently operational in Federal Aviation Administration (FAA) facilities and some are in use by the airlines. These tools have provided air traffic controllers and traffic managers the capabilities to help reduce overall delays and holding, and provide significant cost savings to the airlines as well as more manageable workload levels for air traffic service providers. NASA is continuing to collaborate with the FAA, as well as other government agencies, to plan and develop the next generation of decision support tools that will support anticipated changes in the air transportation system, including a projected increase to three times today's air-traffic levels by 2025. The presentation will review some of NASA Ames' recent achievements in air traffic management research, and discuss future tool developments and concepts currently under consideration.

  6. The AMES network strategy developments within and outside the EU

    Energy Technology Data Exchange (ETDEWEB)

    Sevini, F.; Debarberis, L. [European Commission, JRC, Institute for Advanced Materials, Petten (Netherlands); Davies, L.M. [LMD Consultancy, Oxford (United Kingdom); English, C. [AEA Technology, Oxfordshire (United Kingdom)

    2001-07-01

    The AMES (Ageing Materials Evaluation and Studies) network started its activity in 1993 with the aim of studying the consequences and the mechanisms of the ageing process in materials used for nuclear reactor components. Together with ENIQ, NESC, EPERC, it forms the so-called ''Structural Integrity of Industrial Components'' cluster of networks operated by the Joint Research Centre - Institute for Advanced Materials of the European Commission. After two initial phases dedicated to the compilation of state-of-the-art reports on non-destructive monitoring techniques for thermal ageing, dosimetry, survey of regulatory requirements, predictive formulas for irradiation embrittlement, AMES has entered its third strategy phase with the fifth EURATOM Framework Program, Nuclear Fission Safety Key Action. Most of the projects proposed for this program and sustained by the Steering committee were selected for funding. Their focus is on the influence of chemical composition, namely phosphorus and nickel content, on the irradiation embrittlement of reactor pressure vessel materials, on the improvement of surveillance temperature measurement, on the validation of the Master Curve approach, and on ND techniques to monitor ageing of irradiated steels. The paper describes the objectives of the new fifth Framework Program projects and how they are part of the AMES strategy, pointing out the involvement of CEEC and NIS countries. (authors)

  7. Surface Heparinization of Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    SUN Hui; CHEN Rui-chao; LIU Shu; XU Guo-zhi

    2012-01-01

    Photo-grafting of hydrophilic monomer and space arms was used to enhance the hydrophilicity of poly(ether ether ketone)(PEEK) with the aim of extending its application to biological fields.PEEK films were surface modified by UV grafting of acrylic acid(AA) to introduce-COOH on PEEK surface.Adipic amine was used as a.space ann to introduce heparin on PEEK surface based on the condensation reaction between -NH2 and -COOH.The modified PEEK(PEEK-COOH,PEEK-NH2 and PEEK-Hep) was characterized by energy-disperse spectroscopy (EDS),X-ray photoelectron spectroscopy(XPS) and water contact angle measurements,which show that heparin was grafted on PEEK surface.The contact angles of modified PEEK films were lower than those of original films,demonstrating a significant improvement of surface hydrophilicity.

  8. ETG举办针对EtherCAT产品提供商的EtherCAT培训

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    随着EtherCAT技术的成功推广,越来越多的中国最终用户对EtherCAT技术及其应用感兴趣,并就EtherCAT产品的需求反馈给相关厂商。同时,EtherCAT的产品供应商将更多的ETherCAT投放到中国市场。因此,这些厂商感到更多更深入地了解EtherCAT技术及相关情况将有助于他们开发相关市场。于是,EtherCAT技术协会中国代表处适时举办针对EtherCAT产品提供商的EtherCAT培训。

  9. Carbon-carbon bond cleavage of 1,2-hydroxy ethers b7 vanadium(V) dipicolinate complexes

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, Susan K [Los Alamos National Laboratory; Gordon, John C [Los Alamos National Laboratory; Thorn, David L [Los Alamos National Laboratory; Scott, Brian L [Los Alamos National Laboratory; Baker, R Tom [Los Alamos National Laboratory

    2009-01-01

    The development of alternatives to current petroleum-based fuels and chemicals is becoming increasingly important due to concerns over climate change, growing world energy demand, and energy security issues. Using non-food derived biomass to produce renewable feedstocks for chemicals and fuels is a particularly attractive possibility. However, the majority of biomass is in the form of lignocellulose, which is often not fully utilized due to difficulties associated with breaking down both lignin and cellulose. Recently, a number of methods have been reported to transform cellulose directly into more valuable materials such as glucose, sorbitol, 5-(chloromethyl)furfural, and ethylene glycol. Less progress has been made with selective transformations of lignin, which is typically treated in paper and forest industries by kraft pulping (sodium hydroxide/sodium sulfide) or incineration. Our group has begun investigating aerobic oxidative C-C bond cleavage catalyzed by dipicolinate vanadium complexes, with the idea that a selective C-C cleavage reaction of this type could be used to produce valuable chemicals or intermediates from cellulose or lignin. Lignin is a randomized polymer containing methoxylated phenoxy propanol units. A number of different linkages occur naturally; one of the most prevalent is the {beta}-O-4 linkage shown in Figure 1, containing a C-C bond with 1,2-hydroxy ether substituents. While the oxidative C-C bond cleavage of 1,2-diols has been reported for a number of metals, including vanadium, iron, manganese, ruthenium, and polyoxometalate complexes, C-C bond cleavage of 1,2-hydroxy ethers is much less common. We report herein vanadium-mediated cleavage of C-C bonds between alcohol and ether functionalities in several lignin model complexes. In order to explore the scope and potential of vanadium complexes to effect oxidative C-C bond cleavage in 1,2-hydroxy ethers, we examined the reactivity of the lignin model complexes pinacol monomethyl ether (A

  10. Decrease of intracellular pH as possible mechanism of embryotoxicity of glycol ether alkoxyacetic acid metabolites.

    Science.gov (United States)

    Louisse, Jochem; Bai, Yanqing; Verwei, Miriam; van de Sandt, Johannes J M; Blaauboer, Bas J; Rietjens, Ivonne M C M

    2010-06-01

    Embryotoxicity of glycol ethers is caused by their alkoxyacetic acid metabolites, but the mechanism underlying the embryotoxicity of these acid metabolites is so far not known. The present study investigates a possible mechanism underlying the embryotoxicity of glycol ether alkoxyacetic acid metabolites using the methoxyacetic acid (MAA) metabolite of ethylene glycol monomethyl ether as the model compound. The results obtained demonstrate an MAA-induced decrease of the intracellular pH (pH(i)) of embryonic BALB/c-3T3 cells as well as of embryonic stem (ES)-D3 cells, at concentrations that affect ES-D3 cell differentiation. These results suggest a mechanism for MAA-mediated embryotoxicity similar to the mechanism of embryotoxicity of the drugs valproic acid and acetazolamide (ACZ), known to decrease the pH(i)in vivo, and therefore used as positive controls. The embryotoxic alkoxyacetic acid metabolites ethoxyacetic acid, butoxyacetic acid and phenoxyacetic acid also caused an intracellular acidification of BALB/c-3T3 cells at concentrations that are known to inhibit ES-D3 cell differentiation. Two other embryotoxic compounds, all-trans-retinoic acid and 5-fluorouracil, did not decrease the pH(i) of embryonic cells at concentrations that affect ES-D3 cell differentiation, pointing at a different mechanism of embryotoxicity of these compounds. MAA and ACZ induced a concentration-dependent inhibition of ES-D3 cell differentiation, which was enhanced by amiloride, an inhibitor of the Na(+)/H(+)-antiporter, corroborating an important role of the pH(i) in the embryotoxic mechanism of both compounds. Together, the results presented indicate that a decrease of the pH(i) may be the mechanism of embryotoxicity of the alkoxyacetic acid metabolites of the glycol ethers.

  11. Primordial follicle activation in the ovary of Ames dwarf mice

    OpenAIRE

    Schneider, Augusto; Zhi, Xu; Moreira, Fabiana; Lucia, Thomaz; Mondadori,Rafael Gianella; Masternak, Michal M.

    2014-01-01

    Background The insulin receptor substrate 1 (IRS1), phosphoinositide 3-kinase (Pi3k), protein kinase B (Akt1), Forkhead Box O3a (FOXO3a) pathway is directly involved in aging and ovarian activation of follicle growth. Therefore, the aim of this work was to measure the expression of genes related to the ovarian pathway for activation of primordial follicles and FOXO3a protein phosphorylation between young and old female Ames dwarf (df/df) and normal (N) mice. Methods For this study ovaries fro...

  12. Evolutionary Ensemble for In Silico Prediction of Ames Test Mutagenicity

    Science.gov (United States)

    Chen, Huanhuan; Yao, Xin

    Driven by new regulations and animal welfare, the need to develop in silico models has increased recently as alternative approaches to safety assessment of chemicals without animal testing. This paper describes a novel machine learning ensemble approach to building an in silico model for the prediction of the Ames test mutagenicity, one of a battery of the most commonly used experimental in vitro and in vivo genotoxicity tests for safety evaluation of chemicals. Evolutionary random neural ensemble with negative correlation learning (ERNE) [1] was developed based on neural networks and evolutionary algorithms. ERNE combines the method of bootstrap sampling on training data with the method of random subspace feature selection to ensure diversity in creating individuals within an initial ensemble. Furthermore, while evolving individuals within the ensemble, it makes use of the negative correlation learning, enabling individual NNs to be trained as accurate as possible while still manage to maintain them as diverse as possible. Therefore, the resulting individuals in the final ensemble are capable of cooperating collectively to achieve better generalization of prediction. The empirical experiment suggest that ERNE is an effective ensemble approach for predicting the Ames test mutagenicity of chemicals.

  13. The Atomic Mass Evaluation (AME2012): Status and Perspectives

    Science.gov (United States)

    Kondev, F. G.; Audi, G.; Wang, M.; Xu, X.; Wapstra, A. H.; MacCormick, M.; Pfeiffer, B.

    2013-10-01

    The atomic mass is a fundamental property of the nucleus that has wide applications in natural sciences and technology. The new evaluated mass table, AME2012, has been recently published as a collaborative effort between scientists from China, Europe and USA, under the leadership of G. Audi. It represents a significant update of the previous AME2003 evaluation by considering a large number of precise experimental results obtained at existing Penning Trap and Storage Ring facilities, thus expending the region of experimentally known masses towards exotic neutron- and proton-rich nuclei. Since the presence of isomers plays an important role in determining the masses of many nuclei, a complementary database, NUBASE2012, that contains the isomer-level properties for all nuclei was also developed. This presentation will briefly review recent achievements of the collaboration, present on-going activities, and reflect on ideas for future developments and challenges in the field of evaluation of atomic masses. The work at ANL was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.

  14. NASA Ames Sustainability Initiatives: Aeronautics, Space Exploration, and Sustainable Futures

    Science.gov (United States)

    Grymes, Rosalind A.

    2015-01-01

    In support of the mission-specific challenges of aeronautics and space exploration, NASA Ames produces a wealth of research and technology advancements with significant relevance to larger issues of planetary sustainability. NASA research on NexGen airspace solutions and its development of autonomous and intelligent technologies will revolutionize both the nation's air transporation systems and have applicability to the low altitude flight economy and to both air and ground transporation, more generally. NASA's understanding of the Earth as a complex of integrated systems contributes to humanity's perception of the sustainability of our home planet. Research at NASA Ames on closed environment life support systems produces directly applicable lessons on energy, water, and resource management in ground-based infrastructure. Moreover, every NASA campus is a 'city'; including an urbanscape and a workplace including scientists, human relations specialists, plumbers, engineers, facility managers, construction trades, transportation managers, software developers, leaders, financial planners, technologists, electricians, students, accountants, and even lawyers. NASA is applying the lessons of our mission-related activities to our urbanscapes and infrastructure, and also anticipates a leadership role in developing future environments for living and working in space.

  15. A Perspective on NASA Ames Air Traffic Management Research

    Science.gov (United States)

    Schroeder, Jeffery A.

    2012-01-01

    This paper describes past and present air-traffic-management research at NASA Ames Research Center. The descriptions emerge from the perspective of a technical manager who supervised the majority of this research for the last four years. Past research contributions built a foundation for calculating accurate flight trajectories to enable efficient airspace management in time. That foundation led to two predominant research activities that continue to this day - one in automatically separating aircraft and the other in optimizing traffic flows. Today s national airspace uses many of the applications resulting from research at Ames. These applications include the nationwide deployment of the Traffic Management Advisor, new procedures enabling continuous descent arrivals, cooperation with industry to permit more direct flights to downstream way-points, a surface management system in use by two cargo carriers, and software to evaluate how well flights conform to national traffic management initiatives. The paper concludes with suggestions for prioritized research in the upcoming years. These priorities include: enabling more first-look operational evaluations, improving conflict detection and resolution for climbing or descending aircraft, and focusing additional attention on the underpinning safety critical items such as a reliable datalink.

  16. The viscosity of dimethyl ether

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Jakobsen, Jørgen

    2007-01-01

    Dimethyl ether (DME) has been recognised as an excellent fuel for diesel engines for over one decade now. Engines fuelled by DME emit virtually no particulate matter even at low NOx levels. This is only possible in the case of diesel oil operation if expensive and efficient lowering particles...... for pressurisation in these methods. The results of the VFVM are consolidated by measurements of the viscosities of propane and butane: these agree with the outcome of measurements using a quartz crystal microbalance (QCM) a method that is supposedly less sensible than the Reynolds number....

  17. Enhancer-associated H3K4 monomethylation by trithorax-related, the drosophila homolog of mammalian MLL3/MLL4

    NARCIS (Netherlands)

    H.-M. Herz (Hans-Martin); M. Mohan (Man); A.S. Garruss (Alexander); K. Liang (Kaiwei); Y.-H. Takahashi (Yoh-hei); K. Mickey (Kristen); O. Voets (Olaf); C.P. Verrijzer (Peter); A. Shilatifard (Ali)

    2012-01-01

    textabstractMonomethylation of histone H3 on Lys 4 (H3K4me1) and acetylation of histone H3 on Lys 27 (H3K27ac) are histone modifications that are highly enriched over the body of actively transcribed genes and on enhancers. Although in yeast all H3K4 methylation patterns, including H3K4me1, are impl

  18. Aerial Survey of Ames Research Center - Flight Simulation Complex' Flight simulators create an

    Science.gov (United States)

    1967-01-01

    Aerial Survey of Ames Research Center - Flight Simulation Complex' Flight simulators create an authentic aircraft environment by generating the appropriate physical cues that provide the sensations of flight.

  19. The NRF2 transcriptional target, OSGIN1, contributes to monomethyl fumarate-mediated cytoprotection in human astrocytes

    Science.gov (United States)

    Brennan, Melanie S.; Matos, Maria F.; Richter, Karl E.; Li, Bing; Scannevin, Robert H.

    2017-01-01

    Dimethyl fumarate (DMF) is indicated for the treatment of relapsing multiple sclerosis and may exert therapeutic effects via activation of the nuclear factor (erythroid-derived 2)-like 2 (NRF2) pathway. Following oral DMF administration, central nervous system (CNS) tissue is predominantly exposed to monomethyl fumarate (MMF), the bioactive metabolite of DMF, which can stabilize NRF2 and induce antioxidant gene expression; however, the detailed NRF2-dependent mechanisms modulated by MMF that lead to cytoprotection are unknown. Our data identify a mechanism for MMF-mediated cytoprotection in human astrocytes that functions in an OSGIN1-dependent manner, specifically via upregulation of the OSGIN1-61 kDa isoform. NRF2-dependent OSGIN1 expression induced P53 nuclear translocation following MMF administration, leading to cell-cycle inhibition and cell protection against oxidative challenge. This study provides mechanistic insight into MMF-mediated cytoprotection via NRF2, OSGIN1, and P53 in human CNS-derived cells and contributes to our understanding of how DMF may act clinically to ameliorate pathological processes in neurodegenerative disease. PMID:28181536

  20. Adipose tissue monomethyl branched-chain fatty acids and insulin sensitivity: Effects of obesity and weight loss.

    Science.gov (United States)

    Su, Xiong; Magkos, Faidon; Zhou, Dequan; Eagon, J Christopher; Fabbrini, Elisa; Okunade, Adewole L; Klein, Samuel

    2015-02-01

    An increase in circulating branched-chain amino acids (BCAA) is associated with insulin resistance. Adipose tissue is a potentially important site for BCAA metabolism. It was evaluated whether monomethyl branched-chain fatty acids (mmBCFA) in adipose tissue, which are likely derived from BCAA catabolism, are associated with insulin sensitivity. Insulin-stimulated glucose disposal was determined by using the hyperinsulinemic-euglycemic clamp procedure with stable isotope glucose tracer infusion in nine lean and nine obese subjects, and in a separate group of nine obese subjects before and 1 year after Roux-en-Y gastric bypass (RYGB) surgery (38% weight loss). Adipose tissue mmBCFA content was measured in tissue biopsies taken in the basal state. Total adipose tissue mmBCFA content was ∼30% lower in obese than lean subjects (P=0.02) and increased by ∼65% after weight loss in the RYGB group (P=0.01). Adipose tissue mmBCFA content correlated positively with skeletal muscle insulin sensitivity (R(2) =35%, P=0.01, n=18). These results demonstrate a novel association between adipose tissue mmBCFA content and obesity-related insulin resistance. Additional studies are needed to determine whether the association between adipose tissue mmBCFA and muscle insulin sensitivity is causal or a simple association. © 2014 The Obesity Society.

  1. Synthesis and Characterization of Poly(ether amide)s Containing Bisphthalazinone and Ether Linkages

    Institute of Scientific and Technical Information of China (English)

    Cheng LIU; Shou Hai ZHANG; Ming Jing WANG; Qi Zhen LIANG; Xi Gao JIAN

    2005-01-01

    A novel aromatic diacid, 4, 4'-bis[2-(4-carboxyphenyl)phthalazin-1-one-4-yl]-bisphenyl ether Ⅲ, containing bisphthalazinone and ether linkages was prepared from nucleophilic substitution of p-chlorobenzonitrile with the bisphenol-like monomer Ⅰ, followed by alkaline hydrolysis of the intermediate dinitrile Ⅱ. A series of poly(ether amide)s containing bisphthalazinone and ether linkages derived from diacid Ⅲ and aromatic diamines were synthesized by one-step solution condensation polymerization using triphenyl phosphite and pyridine as condensing agents. Moreover, the properties of poly(ether amide)s including thermal stability,solubility and crystallinity were also studied.

  2. 27 CFR 21.108 - Ethyl ether.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT....108 Ethyl ether. (a) Odor. Characteristic odor. (b) Specific gravity at 15.56 °/15.56 °C. Not...

  3. An expedient synthesis of linden ether.

    Science.gov (United States)

    Serra, Stefano; Cominetti, Alessandra A

    2014-03-01

    We here describe a comprehensive study on the preparation of the intensive flavor 3,9-epoxy-p-mentha-1,4(8)-diene (1). Key steps of the presented synthesis are the selective addition of MeLi to the keto-ester 7, the regioselective cyclization of the obtained triol to give the ethers 4 and 8 and the selective dehydration of ether 4 through the use of POCI3 and pyridine. It is worth noting that the presented synthesis represents the first expedient and reliable entry to ether 1. Being present in linden honey, 1 is also known as linden ether and it has been regarded as a potential marker for the authentication of the linden honey origin. Therefore, ether 1 can be used as a useful reference standard for the analysis of the natural flavors, as we demonstrated by means of its identification in a sample ofunifloral linden honey.

  4. Historical Review of Piloted Simulation at NASA Ames

    Science.gov (United States)

    Anderson, Seth B.

    1996-01-01

    This paper traces the conception and development of in-flight and ground based simulators at NASA Ames Research Center, starting in 1947 and continuing to the early 1990's. Problems with their development and operation and how limitations were handled are recounted. Advances needed in simulator equipment to improve performance and fidelity to gain pilot acceptance are discussed. The uses of these simulators in various aircraft research and development programs and their importance to aircraft design and flight testing are reviewed. Challenges remaining include a better understanding of the tradeoff between motion cues and visual cues, the importance of simulation sophistication when examining aircraft with marginal handling qualities characteristics, and the continuing need for upgrading simulation technology as more complex problems are encountered. Additional research is needed to understand the human behavior aspect in the pilot/simulator system.

  5. Scientific visualization in computational aerodynamics at NASA Ames Research Center

    Science.gov (United States)

    Bancroft, Gordon V.; Plessel, Todd; Merritt, Fergus; Walatka, Pamela P.; Watson, Val

    1989-01-01

    The visualization methods used in computational fluid dynamics research at the NASA-Ames Numerical Aerodynamic Simulation facility are examined, including postprocessing, tracking, and steering methods. The visualization requirements of the facility's three-dimensional graphical workstation are outlined and the types hardware and software used to meet these requirements are discussed. The main features of the facility's current and next-generation workstations are listed. Emphasis is given to postprocessing techniques, such as dynamic interactive viewing on the workstation and recording and playback on videodisk, tape, and 16-mm film. Postprocessing software packages are described, including a three-dimensional plotter, a surface modeler, a graphical animation system, a flow analysis software toolkit, and a real-time interactive particle-tracer.

  6. Reduced Crew Operations Research at NASA Ames Research Center

    Science.gov (United States)

    Brandt, Summer L.; Lachter, Joel

    2017-01-01

    In 2012, NASA began exploring the feasibility of single pilot reduced crew operations (SPORCO) in the context of scheduled passenger air carrier operations (i.e., Parts 121 and 135). This research was spurred by two trends in aviation research: the trend toward reducing costs and a shortage of pilots. A series of simulations were conducted to develop tools and a concept of operations to support RCO. This slide deck is a summary of the NASA Ames RCO research prepared for an R T team at Airbus. Airbus is considering moving forward with reducing crew during the cruise phase of flight with long-haul flights and is interested in the work we have completed.

  7. Mutagenicity of Flavonoids Assayed by Bacterial Reverse Mutation (Ames Test

    Directory of Open Access Journals (Sweden)

    Eliana Aparecida Varanda

    2012-05-01

    Full Text Available The mutagenicity of ten flavonoids was assayed by the Ames test, in Salmonella typhimurium strains TA98, TA100 and TA102, with the aim of establishing hydroxylation pattern-mutagenicity relationship profiles. The compounds assessed were: quercetin, kaempferol, luteolin, fisetin, chrysin, galangin, flavone, 3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone. In the Ames assay, quercetin acted directly and its mutagenicity increased with metabolic activation. In the presence of S9 mix, kaempferol and galangin were mutagenic in the TA98 strain and kaempferol showed signs of mutagenicity in the other strains. The absence of hydroxyl groups, as in flavone, only signs of mutagenicity were shown in strain TA102, after metabolization and, among monohydroxylated flavones (3-hydroxyflavone, 5-hydroxyflavone and 7-hydroxyflavone, the presence of hydroxyl groups only resulted in minor changes. Luteolin and fisetin also showed signs of mutagenicity in strain TA102. Finally, chrysin, which has only two hydroxy groups, at the 5-OH and 7-OH positions, also did not induce mutagenic activity in any of the bacterial strains used, under either activation condition. All the flavonoids were tested at concentrations varying from 2.6 to 30.7 nmol/plate for galangin and 12.1 to 225.0 nmol/plate for other flavonoids. In light of the above, it is necessary to clarify the conditions and the mechanisms that mediate the biological effects of flavonoids before treating them as therapeutical agents, since some compounds can be biotransformed into more genotoxic products; as is the case for galangin, kaempferol and quercetin.

  8. A new alternative to expandable pedicle screws: Expandable poly-ether-ether-ketone shell.

    Science.gov (United States)

    Demir, Teyfik

    2015-05-01

    Screw pullout is a very common problem in the fixation of sacrum with pedicle screws. The principal cause of this problem is that the cyclic micro motions in the fixation of sacrum are higher than the other regions of the vertebrae that limit the osteo-integration between bone and screw. In addition to that, the bone quality is very poor at sacrum region. This study investigated a possible solution to the pullout problem without the expandable screws' handicaps. Newly designed poly-ether-ether-ketone expandable shell and classical pedicle screws were biomechanically compared. Torsion test, pullout tests, fatigue tests, flexion/extension moment test, axial gripping capacity tests and torsional gripping capacity tests were conducted in accordance with ASTM F543, F1798 and F1717. Standard polyurethane foam and calf vertebrae were used as embedding medium for pullout tests. Classical pedicle screw pullout load on polyurethane foam was 564.8 N compared to the failure load for calf vertebrae's 1264 N. Under the same test conditions, expandable poly-ether-ether-ketone shell system's pullout loads from polyurethane foam and calf vertebrae were 1196.3 and 1890 N, respectively. The pullout values for expandable poly-ether-ether-ketone shell were 33% and 53% higher than classical pedicle screw on polyurethane foam and calf vertebrae, respectively. The expandable poly-ether-ether-ketone shell exhibited endurance on its 90% of yield load. Contrary to poly-ether-ether-ketone shell, classical pedicle screw exhibited endurance on 70% of its yield load. Expandable poly-ether-ether-ketone shell exhibited much higher pullout performance than classical pedicle screw. Fatigue performance of expandable poly-ether-ether-ketone shell is also higher than classical pedicle screw due to damping the micro motion capacity of the poly-ether-ether-ketone. Expandable poly-ether-ether-ketone shell is a safe alternative to all other expandable pedicle screw systems on mechanical perspective

  9. Photopolymerization of Glycerin Triglycidyl Ether Based Systems

    Institute of Scientific and Technical Information of China (English)

    HUANG Biwu; CHEN Yiwang; DENG Qilan

    2008-01-01

    Photopolymerization process of glycerin triglycidyl ether based systems was studied by an FT-IR spectrometer.An increase in the rate of polymerization for glycerin triglycidyl ether was evident when 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate was added to it.Its copolymerization mechanism was confirmed by using DSC analysis.The effect of ethoxylated trimethyol propane triacrylate on the rate of polymerization for glycerin triglycidyl ether was also studied,and the formation of interpenetrating network tightly cross-link was proposed.

  10. Alternaria toxins: Altertoxin II is a much stronger mutagen and DNA strand breaking mycotoxin than alternariol and its methyl ether in cultured mammalian cells.

    Science.gov (United States)

    Fleck, Stefanie C; Burkhardt, Britta; Pfeiffer, Erika; Metzler, Manfred

    2012-10-02

    Altertoxin II (ATX II) is one of the several mycotoxins produced by Alternaria fungi. It has a perylene quinone structure and is highly mutagenic in Ames Salmonella typhimurium, but its mutagenicity in mammalian cells has not been studied before. Here we report that ATX II is a potent mutagen in cultured Chinese hamster V79 cells, inducing a concentration-dependent increase of mutations at the hypoxanthine guanine phosphoribosyltransferase gene locus at concentrations similar to that of the established mutagen 4-quinoline-N-oxide. Thus, ATX II is at least 50-times more potent as a mutagen than the common Alternaria toxins alternariol (AOH) and alternariol methyl ether (AME). In contrast to AOH and AME, ATX II does not affect the cell cycle of V79 cells. ATX II also causes DNA strand breaks in V79 cells, with a potency again exceeding that of AOH and AME. The high mutagenic and DNA strand breaking activity of ATX II raises the question of whether this Alternaria toxin poses a risk for public health, and warrants studies on the occurrence of ATX II and other perylene quinone-type mycotoxins in food and feed.

  11. A transferable force field to predict phase equilibria and surface tension of ethers and glycol ethers.

    Science.gov (United States)

    Ferrando, Nicolas; Lachet, Véronique; Pérez-Pellitero, Javier; Mackie, Allan D; Malfreyt, Patrice; Boutin, Anne

    2011-09-15

    We propose a new transferable force field to simulate phase equilibrium and interfacial properties of systems involving ethers and glycol ethers. On the basis of the anisotropic united-atom force field, only one new group is introduced: the ether oxygen atom. The optimized Lennard-Jones (LJ) parameters of this atom are identical whatever the molecule simulated (linear ether, branched ether, cyclic ether, aromatic ether, diether, or glycol ether). Accurate predictions are achieved for pure compound saturated properties, critical properties, and surface tensions of the liquid-vapor interface, as well as for pressure-composition binary mixture diagrams. Multifunctional molecules (1,2-dimethoxyethane, 2-methoxyethanol, diethylene glycol) have also been studied using a recently proposed methodology for the calculation of the intramolecular electrostatic energy avoiding the use of additional empirical parameters. This new force field appears transferable for a wide variety of molecules and properties. It is furthermore worth noticing that binary mixtures have been simulated without introducing empirical binary parameters, highlighting also the transferability to mixtures. Hence, this new force field gives future opportunities to simulate complex systems of industrial interest involving molecules with ether functions.

  12. 基于FPGA的EtherCAT从站节点开发%FPGA- based Development of EtherCAT Slave Node

    Institute of Scientific and Technical Information of China (English)

    李昆; 杨建武

    2011-01-01

    随着实时工业以太网技术在工业自动化领域的发展和应用,德国倍福公司推出的EtherCAT技术尤其备受瞩目.EtherCAT技术的核心在于EtherCAT通信机制、EtherCAT主站和EtherCAT从站节点.EtherCAT从站节点通常是采用EtherCAT从站控制芯片和从站控制微处理器来设计实现的,对此提出了一种使用FPGA技术开发实现EtherCAT从站节点功能的方法,并验证了方法的可行性.%With the development and application of the real - time industrial Ethernet technology in industrial automation, EtherCAT technology introduced by Beckhoff is especially well received. The core of EtherCAT technology is the EtherCAT communication mechanisms, EtherCAT Master and EtherCAT Slave Node. EtherCAT slave node is usually designed by using EtherCAT slave controller chip and slave control microprocessor chip to achieve its function, this paper presents a method which is using FPGA technology to develop the EtherCAT slave node, and verifies the feasibility of it.

  13. Vacuum condensates and `ether-drift' experiments

    OpenAIRE

    Consoli, M.; Pagano, A.; Pappalardo, L.

    2003-01-01

    The idea of a `condensed' vacuum state is generally accepted in modern elementary particle physics. We argue that this should motivate a new generation of precise `ether-drift' experiments with present-day technology.

  14. Activity relationships for aromatic crown ethers

    CERN Document Server

    Wilson, M J

    1998-01-01

    This thesis involves an investigation of aromatic crown ethers and a study of their binding constants for alkali metals. The study was motivated by the current needs of the semiconductor industry to improve the scavenging of mobile ions from fabricated circuits. A number of aromatic crown ethers have been sulphonated in an attempt to improve their water solubility and cation binding activity. These materials have been extensively studied and their binding activity determined. In collaboration with a molecular modelling study, the effect of ionisable sulphonate groups on the macrocycles' behaviour has been investigated. The broader issue of the effect of substituents in aromatic crown ethers has also been studied with the preparation of a wide range of substituted crown ethers. The cation binding activity of these materials has been found to bear a simple relationship to the electron withdrawing nature of the aromatic substituents. This relationship can be accurately monitored using electronic charge densities...

  15. Exogenous ether lipids predominantly target mitochondria

    DEFF Research Database (Denmark)

    Kuerschner, Lars; Richter, Doris; Hannibal-Bach, Hans Kristian

    2012-01-01

    Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high......, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria...

  16. NASA Ames Research Center 60 MW Power Supply Modernization

    Science.gov (United States)

    Choy, Yuen Ching; Ilinets, Boris V.; Miller, Ted; Nagel, Kirsten (Technical Monitor)

    2001-01-01

    The NASA Ames Research Center 60 MW DC Power Supply was built in 1974 to provide controlled DC power for the Thermophysics Facility Arc Jet Laboratory. The Power Supply has gradually losing reliability due to outdated technology and component life limitation. NASA has decided to upgrade the existing rectifier modules with contemporary high-power electronics and control equipment. NASA plans to complete this project in 2001. This project includes a complete replacement of obsolete thyristor stacks in all six rectifier modules and rectifier bridge control system. High power water-cooled thyristors and freewheeling diodes will be used. The rating of each of the six modules will be 4000 A at 5500 V. The control firing angle signal will be sent from the Facility Control System to six modules via fiberoptic cable. The Power Supply control and monitoring system will include a Master PLC in the Facility building and a Slave PLC in each rectifier module. This system will also monitor each thyristor level in each stack and the auxiliary equipment.

  17. Ethnography in qualitative educational research: AMEE Guide No. 80.

    Science.gov (United States)

    Reeves, Scott; Peller, Jennifer; Goldman, Joanne; Kitto, Simon

    2013-08-01

    Ethnography is a type of qualitative research that gathers observations, interviews and documentary data to produce detailed and comprehensive accounts of different social phenomena. The use of ethnographic research in medical education has produced a number of insightful accounts into its role, functions and difficulties in the preparation of medical students for clinical practice. This AMEE Guide offers an introduction to ethnography - its history, its differing forms, its role in medical education and its practical application. Specifically, the Guide initially outlines the main characteristics of ethnography: describing its origins, outlining its varying forms and discussing its use of theory. It also explores the role, contribution and limitations of ethnographic work undertaken in a medical education context. In addition, the Guide goes on to offer a range of ideas, methods, tools and techniques needed to undertake an ethnographic study. In doing so it discusses its conceptual, methodological, ethical and practice challenges (e.g. demands of recording the complexity of social action, the unpredictability of data collection activities). Finally, the Guide provides a series of final thoughts and ideas for future engagement with ethnography in medical education. This Guide is aimed for those interested in understanding ethnography to develop their evaluative skills when reading such work. It is also aimed at those interested in considering the use of ethnographic methods in their own research work.

  18. Research activity at the shock tube facility at NASA Ames

    Science.gov (United States)

    Sharma, Surendra P.

    1992-01-01

    The real gas phenomena dominate the relaxation process occurring in the flow around hypersonic vehicles. The air flow around these vehicles undergoes vibrational excitation, chemical dissociation, and ionization. These chemical and kinetic phenomena absorb energy, change compressibility, cause temperature to fall, and density to rise. In high-altitude, low density environments, the characteristic thicknesses of the shock layers can be smaller than the relaxation distances required for the gas to attain chemical and thermodynamic equilibrium. To determine the effects of chemical nonequilibrium over a realistic hypersonic vehicle, it would be desirable to conduct an experiment in which all aspects of fluid flow are simulated. Such an experiment is extremely difficult to setup. The only practical alternative is to develop a theoretical model of the phenomena and to compute the flow around the vehicle including the chemical nonequilibrium, and compare the results with the experiments conducted in the facilities under conditions where only a portion of the flow phenomena is simulated. Three types of experimental data are needed to assist the aerospace community in this model development process: (1) data which will enhance our phenomenological understanding of the relaxation process, (2) data on rate reactions for the relevant reactions, and (3) data on bulk properties, such as spectral radiation emitted by the gas, for a given set of aerodynamic conditions. NASA Ames is in a process of collecting such data by simulating the required aerothermochemical conditions in an electric arc driven shock tube.

  19. Medical education scholarship: an introductory guide: AMEE Guide No. 89.

    Science.gov (United States)

    Crites, Gerald E; Gaines, Julie K; Cottrell, Scott; Kalishman, Summers; Gusic, Maryellen; Mavis, Brian; Durning, Steven J

    2014-08-01

    Abstract This AMEE Guide provides an overview of medical education scholarship for early career scholars, based upon a summary of the existing literature and pragmatic advice derived from the experience of its authors. After providing an introduction to the principles of scholarship and describing questions that the Guide addresses, the authors offer a conceptual description of the complementary traditions of teaching and educational discovery, and advocate for the development of educational scholars with both traditions. They then describe the attributes of effective mentor-mentee relationships and how early career scholars can identify potential mentors who can fulfill this role. In the subsequent sections, they describe the appropriate development of scholarly questions and other components of a complete scholarly plan, including how to use conceptual frameworks in guiding such plans. From here, they describe methods that align with both the teaching and discovery traditions and provide concrete examples of each. They then provide guidelines for assessing the impact of scholarship, identify the various opportunities for sharing it, and how to effectively interpret and describe it. Additionally, they provide practical advice on how appropriately to demonstrate the scholarship in a promotional packet, including the principle of reflectivity in scholarship. Finally, they address the principles of applied research ethics for educational scholarship and when to consider soliciting approval for scholarly activities by a human research board.

  20. Mobile technologies in medical education: AMEE Guide No. 105.

    Science.gov (United States)

    Masters, Ken; Ellaway, Rachel H; Topps, David; Archibald, Douglas; Hogue, Rebecca J

    2016-06-01

    Mobile technologies (including handheld and wearable devices) have the potential to enhance learning activities from basic medical undergraduate education through residency and beyond. In order to use these technologies successfully, medical educators need to be aware of the underpinning socio-theoretical concepts that influence their usage, the pre-clinical and clinical educational environment in which the educational activities occur, and the practical possibilities and limitations of their usage. This Guide builds upon the previous AMEE Guide to e-Learning in medical education by providing medical teachers with conceptual frameworks and practical examples of using mobile technologies in medical education. The goal is to help medical teachers to use these concepts and technologies at all levels of medical education to improve the education of medical and healthcare personnel, and ultimately contribute to improved patient healthcare. This Guide begins by reviewing some of the technological changes that have occurred in recent years, and then examines the theoretical basis (both social and educational) for understanding mobile technology usage. From there, the Guide progresses through a hierarchy of institutional, teacher and learner needs, identifying issues, problems and solutions for the effective use of mobile technology in medical education. This Guide ends with a brief look to the future.

  1. International round-robin study on the Ames fluctuation test.

    Science.gov (United States)

    Reifferscheid, G; Maes, H M; Allner, B; Badurova, J; Belkin, S; Bluhm, K; Brauer, F; Bressling, J; Domeneghetti, S; Elad, T; Flückiger-Isler, S; Grummt, H J; Gürtler, R; Hecht, A; Heringa, M B; Hollert, H; Huber, S; Kramer, M; Magdeburg, A; Ratte, H T; Sauerborn-Klobucar, R; Sokolowski, A; Soldan, P; Smital, T; Stalter, D; Venier, P; Ziemann, Chr; Zipperle, J; Buchinger, S

    2012-04-01

    An international round-robin study on the Ames fluctuation test [ISO 11350, 2012], a microplate version of the classic plate-incorporation method for the detection of mutagenicity in water, wastewater and chemicals was performed by 18 laboratories from seven countries. Such a round-robin study is a precondition for both the finalization of the ISO standardization process and a possible regulatory implementation in water legislation. The laboratories tested four water samples (spiked/nonspiked) and two chemical mixtures with and without supplementation of a S9-mix. Validity criteria (acceptable spontaneous and positive control-induced mutation counts) were fulfilled by 92-100%, depending on the test conditions. A two-step method for statistical evaluation of the test results is proposed and assessed in terms of specificity and sensitivity. The data were first subjected to powerful analysis of variance (ANOVA) after an arcsine-square-root transformation to detect significant differences between the test samples and the negative control (NC). A threshold (TH) value based on a pooled NC was then calculated to exclude false positive test results. Statistically, positive effects observed by the William's test were considered negative, if the mean of all replicates of a sample did not exceed the calculated TH. By making use of this approach, the overall test sensitivity was 100%, and the test specificity ranged from 80 to 100%.

  2. Writing competitive research conference abstracts: AMEE Guide no. 108.

    Science.gov (United States)

    Varpio, Lara; Amiel, Jonathan; Richards, Boyd F

    2016-09-01

    The ability to write a competitive research conference abstract is an important skill for medical educators. A compelling and concise abstract can convince peer reviewers, conference selection committee members, and conference attendees that the research described therein is worthy for inclusion in the conference program and/or for their attendance in the meeting. This AMEE Guide is designed to help medical educators write research conference abstracts that can achieve these outcomes. To do so, this Guide begins by examining the rhetorical context (i.e. the purpose, audience, and structure) of research conference abstracts and then moves on to describe the abstract selection processes common to many medical education conferences. Next, the Guide provides theory-based information and concrete suggestions on how to write persuasively. Finally, the Guide offers some writing tips and some proofreading techniques that all authors can use. By attending to the aspects of the research conference abstract addressed in this Guide, we hope to help medical educators enhance this important text in their writing repertoire.

  3. Thin sulfonated poly(ether ether ketone) films for the dehydration of compressed carbon dioxide

    NARCIS (Netherlands)

    Koziara, B.T.

    2015-01-01

    In this thesis, the properties of thin films from highly sulfonated poly(ether ether ketone) (SPEEK) have been investigated within the context of their application as membranes for the dehydration of compressed carbon dioxide. Spectroscopic ellipsometry has been used as the predominant measurement t

  4. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, Beata; Nijmeijer, Dorothea C.; Benes, Nieck Edwin

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds

  5. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, B.T.; Nijmeijer, D.C.; Benes, N.E.

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds (C20

  6. Making Stuff Outreach at the Ames Laboratory and Iowa State University

    Energy Technology Data Exchange (ETDEWEB)

    Ament, Katherine; Karsjen, Steven; Leshem-Ackerman, Adah; King, Alexander

    2011-04-01

    The U. S. Department of Energy's Ames Laboratory in Ames, Iowa was a coalition partner for outreach activities connected with NOVA's Making Stuff television series on PBS. Volunteers affiliated with the Ames Laboratory and Iowa State University, with backgrounds in materials science, took part in activities including a science-themed Family Night at a local mall, Science Cafes at the Science Center of Iowa, teacher workshops, demonstrations at science nights in elementary and middle schools, and various other events. We describe a selection of the activities and present a summary of their outcomes and extent of their impact on Ames, Des Moines and the surrounding communities in Iowa. In Part 2, results of a volunteer attitude survey are presented, which shed some light on the volunteer experience and show how the volunteers participation in outreach activities has affected their views of materials education.

  7. Analysis of Hexanitrostilbene (HNS) and Dipicryethane (DPE) for Mutagenicity by the Ames/Salmonella Assay

    Energy Technology Data Exchange (ETDEWEB)

    Wu, R; Felton, J

    2007-10-12

    The Ames/Salmonella assay, developed by Professor Bruce Ames at the University of California, Berkeley, is a rapid and sensitive assay for detecting mutagenicity of various chemical compounds (Maron and Ames, 1983). It is a widely accepted short-term assay for detecting chemicals that induce mutations in the histidine (his) gene of Salmonella typhimurium. This is a reverse mutation assay that detects the mutational reversion of his-dependent Salmonella to the his-independent counterpart. Thereby, mutagenic compounds will increase the frequency of occurrence of his-independent bacterial colonies. The assay utilizes the specific genetically constructed strains of bacteria either with or without mammalian metabolic activation enzymes (S9), Aroclor induced rat liver homogenate to assess the mutagenicity of different compounds. In this study, we will use the Ames/Salmonella assay to investigate the mutagenicity of Hexanitrostilbene (HNS) from both Bofors and Pantex, and Dipicryethane (DPE).

  8. Crystal structures of eight mono-methyl alkanes (C26–C32 via single-crystal and powder diffraction and DFT-D optimization

    Directory of Open Access Journals (Sweden)

    Lee Brooks

    2015-09-01

    Full Text Available The crystal structures of eight mono-methyl alkanes have been determined from single-crystal or high-resolution powder X-ray diffraction using synchrotron radiation. Mono-methyl alkanes can be found on the cuticles of insects and are believed to act as recognition pheromones in some social species, e.g. ants, wasps etc. The molecules were synthesized as pure S enantiomers and are (S-9-methylpentacosane, C26H54; (S-9-methylheptacosane and (S-11-methylheptacosane, C28H58; (S-7-methylnonacosane, (S-9-methylnonacosane, (S-11-methylnonacosane and (S-13-methylnonacosane, C30H62; and (S-9-methylhentriacontane, C32H66. All crystallize in space group P21. Depending on the position of the methyl group on the carbon chain, two packing schemes are observed, in which the molecules pack together hexagonally as linear rods with terminal and side methyl groups clustering to form distinct motifs. Carbon-chain torsion angles deviate by less than 10° from the fully extended conformation, but with one packing form showing greater curvature than the other near the position of the methyl side group. The crystal structures are optimized by dispersion-corrected DFT calculations, because of the difficulties in refining accurate structural parameters from powder diffraction data from relatively poorly crystalline materials.

  9. Mercury, monomethyl mercury, and dissolved organic carbon concentrations in surface water entering and exiting constructed wetlands treated with metal-based coagulants, Twitchell Island, California

    Science.gov (United States)

    Stumpner, Elizabeth B.; Kraus, Tamara E.C.; Fleck, Jacob A.; Hansen, Angela M.; Bachand, Sandra M.; Horwath, William R.; DeWild, John F.; Krabbenhoft, David P.; Bachand, Philip A.M.

    2015-09-02

    Coagulation with metal-based salts is a practice commonly employed by drinking-water utilities to decrease particle and dissolved organic carbon concentrations in water. In addition to decreasing dissolved organic carbon concentrations, the effectiveness of iron- and aluminum-based coagulants for decreasing dissolved concentrations both of inorganic and monomethyl mercury in water was demonstrated in laboratory studies that used agricultural drainage water from the Sacramento–San Joaquin Delta of California. To test the effectiveness of this approach at the field scale, nine 15-by-40‑meter wetland cells were constructed on Twitchell Island that received untreated water from island drainage canals (control) or drainage water treated with polyaluminum chloride or ferric sulfate coagulants. Surface-water samples were collected approximately monthly during November 2012–September 2013 from the inlets and outlets of the wetland cells and then analyzed by the U.S. Geological Survey for total concentrations of mercury and monomethyl mercury in filtered (less than 0.3 micrometers) and suspended-particulate fractions and for concentrations of dissolved organic carbon.

  10. Crystal structures of eight mono-methyl alkanes (C26-C32) via single-crystal and powder diffraction and DFT-D optimization.

    Science.gov (United States)

    Brooks, Lee; Brunelli, Michela; Pattison, Philip; Jones, Graeme R; Fitch, Andrew

    2015-09-01

    The crystal structures of eight mono-methyl alkanes have been determined from single-crystal or high-resolution powder X-ray diffraction using synchrotron radiation. Mono-methyl alkanes can be found on the cuticles of insects and are believed to act as recognition pheromones in some social species, e.g. ants, wasps etc. The molecules were synthesized as pure S enantiomers and are (S)-9-methylpentacosane, C26H54; (S)-9-methylheptacosane and (S)-11-methylheptacosane, C28H58; (S)-7-methylnonacosane, (S)-9-methylnonacosane, (S)-11-methylnonacosane and (S)-13-methylnonacosane, C30H62; and (S)-9-methylhentriacontane, C32H66. All crystallize in space group P21. Depending on the position of the methyl group on the carbon chain, two packing schemes are observed, in which the molecules pack together hexagonally as linear rods with terminal and side methyl groups clustering to form distinct motifs. Carbon-chain torsion angles deviate by less than 10° from the fully extended conformation, but with one packing form showing greater curvature than the other near the position of the methyl side group. The crystal structures are optimized by dispersion-corrected DFT calculations, because of the difficulties in refining accurate structural parameters from powder diffraction data from relatively poorly crystalline materials.

  11. Thermodynamic equilibrium calculations of dimethyl ether steam reforming and dimethyl ether hydrolysis

    Science.gov (United States)

    Semelsberger, Troy A.; Borup, Rodney L.

    The production of a hydrogen-rich fuel-cell feed by dimethyl ether (DME) steam reforming was investigated using calculations of thermodynamic equilibrium as a function of steam-to-carbon ratio (0.00-4.00), temperature (100-600 °C), pressure (1-5 atm), and product species. Species considered were acetone, acetylene, carbon dioxide, carbon monoxide, dimethyl ether, ethane, ethanol, ethylene, formaldehyde, formic acid, hydrogen, isopropanol, methane, methanol, methyl-ethyl ether, n-propanol and water. Thermodynamic equilibrium calculations of DME steam reforming indicate complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide at temperatures greater than 200 °C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure ( P = 1 atm). Increasing the operating pressure shifts the equilibrium toward the reactants; increasing the pressure from 1 to 5 atm decreases the conversion of dimethyl ether from 99.5 to 76.2%. The trend of thermodynamically stable products in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol-formaldehyde, formic acid, and acetylene were not observed. Based on the equilibrium calculations, the optimal processing conditions for dimethyl ether steam reforming occur at a steam-to-carbon ratio of 1.50, a pressure of 1 atm, and a temperature of 200 °C. These thermodynamic equilibrium calculations show dimethyl ether processed with steam will produce hydrogen-rich fuel-cell feeds—with hydrogen concentrations exceeding 70%. The conversion of dimethyl ether via hydrolysis (considering methanol as the only product) is limited by thermodynamic equilibrium. Equilibrium conversion increases with temperature and steam-to-carbon ratio. A maximum dimethyl ether conversion of 62% is achieved at a steam-to-carbon ratio of 5.00 and a processing temperature of 600 °C.

  12. "Ames Research Center: Linking our Origins to our Future"

    Science.gov (United States)

    DesMarais, David J.

    2005-01-01

    Our research traces a path from interstellar materials to inhabited worlds and beyond. We examine how protoplanetary disks evolve and form terrestrial planets, the evolutionary paths of habitable planets, and how external factors (e.g., orbital eccentricity) and internal factors (atmospheric circulation) affect habitability. We trace, spectroscopically and chemically, the evolution of organic molecules from the interstellar medium onto habitable bodies. We examine how membranes might form under prebiotic planetary conditions. We evolve proteins capable of sustaining early metabolism, such as synthesis of biopolymers and transport of ions across membranes. We estimate the frequency of finding a functional prebiotic protein that formed spontaneously. We characterize the formation of diagnostic microbial biosignatures in rock-hosted ecosystems in ophiolite springs as an analog for subsurface life within our solar system, and photosynthetic microbial mats as biota that could be detected on extrasolar planets. We develop quantitative models that simulate energy relationships, biogeochemical cycling, trace gas exchange, and biodiversity. We examine the effects of climate variability on a vegetation-rich biosphere over intermediate time scales, using South American ecosystems as a model. We address natural transport of life beyond its planet of origin, such as on a meteorite, where survivors must withstand radiation, desiccation, and time in transit. We fly organisms and ecosystems in low Earth orbit to test their resistance to space. The Ames E&PO program disseminates these themes to national- and international-scale audiences through partnerships with the California Academy of Sciences, Yellow stone National Park, New York Hall of Science, and several K-14 educational organizations.

  13. Flight Test 4 Preliminary Results: NASA Ames SSI

    Science.gov (United States)

    Isaacson, Doug; Gong, Chester; Reardon, Scott; Santiago, Confesor

    2016-01-01

    Realization of the expected proliferation of Unmanned Aircraft System (UAS) operations in the National Airspace System (NAS) depends on the development and validation of performance standards for UAS Detect and Avoid (DAA) Systems. The RTCA Special Committee 228 is charged with leading the development of draft Minimum Operational Performance Standards (MOPS) for UAS DAA Systems. NASA, as a participating member of RTCA SC-228 is committed to supporting the development and validation of draft requirements as well as the safety substantiation and end-to-end assessment of DAA system performance. The Unmanned Aircraft System (UAS) Integration into the National Airspace System (NAS) Project conducted flight test program, referred to as Flight Test 4, at Armstrong Flight Research Center from April -June 2016. Part of the test flights were dedicated to the NASA Ames-developed Detect and Avoid (DAA) System referred to as JADEM (Java Architecture for DAA Extensibility and Modeling). The encounter scenarios, which involved NASA's Ikhana UAS and a manned intruder aircraft, were designed to collect data on DAA system performance in real-world conditions and uncertainties with four different surveillance sensor systems. Flight test 4 has four objectives: (1) validate DAA requirements in stressing cases that drive MOPS requirements, including: high-speed cooperative intruder, low-speed non-cooperative intruder, high vertical closure rate encounter, and Mode CS-only intruder (i.e. without ADS-B), (2) validate TCASDAA alerting and guidance interoperability concept in the presence of realistic sensor, tracking and navigational errors and in multiple-intruder encounters against both cooperative and non-cooperative intruders, (3) validate Well Clear Recovery guidance in the presence of realistic sensor, tracking and navigational errors, and (4) validate DAA alerting and guidance requirements in the presence of realistic sensor, tracking and navigational errors. The results will be

  14. 3rd Annual NASA Ames Space Science and Astrobiology Jamboree

    Science.gov (United States)

    Dotson, Jessie

    2015-01-01

    The Space Science and Astrobiology Division at NASA Ames Research Center consists of over 50 civil servants and more than 110 contractors, co-­-ops, post-­-docs and associates. Researchers in the division are pursuing investigations in a variety of fields including exoplanets, planetary science, astrobiology and astrophysics. In addition, division personnel support a wide variety of NASA missions including (but not limited to) Kepler, SOFIA, LADEE, JWST, and New Horizons. With such a wide variety of interesting research going on, distributed among three branches in at least 5 different buildings, it can be difficult to stay abreast of what one's fellow researchers are doing. Our goal in organizing this symposium is to facilitate communication and collaboration among the scientists within the division, and to give center management and other ARC researchers and engineers an opportunity to see what scientific research and science mission work is being done in the division. We are also continuing the tradition within the Space Science and Astrobiology Division to honor one senior and one early career scientist with the Pollack Lecture and the Early Career Lecture, respectively. With the Pollack Lecture, our intent is to select a senior researcher who has made significant contributions to any area of research within the space sciences, and we are pleased to honor Dr. William Borucki this year. With the Early Career Lecture, our intent is to select a young researcher within the division who, by their published scientific papers, shows great promise for the future in any area of space science research, and we are pleased to honor Dr. Melinda Kahre this year

  15. Thyroxine modifies the effects of growth hormone in Ames dwarf mice

    OpenAIRE

    Do, Andrew; Menon, Vinal; Zhi, Xu; Gesing, Adam; Wiesenborn, Denise S.; Spong, Adam; Sun, Liou; Bartke, Andrzej; Masternak, Michal M.

    2015-01-01

    Ames dwarf (df/df) mice lack growth hormone (GH), thyroid stimulating hormone and prolactin. Treatment of juvenile df/df mice with GH alone stimulates somatic growth, reduces insulin sensitivity and shortens lifespan. Early‐life treatment with thyroxine (T4) alone produces modest growth stimulation but does not affect longevity. In this study, we examined the effects of treatment of juvenile Ames dwarf mice with a combination of GH + T4 and compared them to the effects of GH alone. Treatment ...

  16. The AME2016 atomic mass evaluation (I). Evaluation of input data; and adjustment procedures

    Energy Technology Data Exchange (ETDEWEB)

    Huang, W. J.; Audi, G.; Wang, Meng; Kondev, F. G.; Naimi, S.; Xu, Xing

    2017-03-01

    This paper is the first of two articles (Part I and Part II) that presents the results of the new atomic mass evaluation, Ame2016. It includes complete information on the experimental input data (also including unused and rejected ones), as well as details on the evaluation procedures used to derive the tables of recommended values given in the second part. This article describes the evaluation philosophy and procedures that were implemented in the selection of specific nuclear reaction, decay and mass-spectrometric results. These input values were entered in the least-squares adjustment for determining the best values for the atomic masses and their uncertainties. Details of the calculation and particularities of the Ame are then described. All accepted and rejected data, including outweighted ones, are presented in a tabular format and compared with the adjusted values obtained using the least-squares fit analysis. Differences with the previous Ame2012 evaluation are discussed and specific information is presented for several cases that may be of interest to Ame users. The second Ame2016 article gives a table with the recommended values of atomic masses, as well as tables and graphs of derived quantities, along with the list of references used in both the Ame2016 and the Nubase2016 evaluations (the first paper in this issue). Amdc: http://amdc.impcas.ac.cn/

  17. The AME2012 atomic mass evaluation (Ⅰ).Evaluation of input data, adjustment procedures

    Institute of Scientific and Technical Information of China (English)

    G.Audi; M.Wang; A.H.Wapstra; F.G.Kondev; M.MacCormick; X.Xu; B.Pfeiffer

    2012-01-01

    This paper is the first of two articles (Part Ⅰ and Part Ⅱ) that presents the results of the new atomic mass evaluation,AME2012.It includes complete information on the experimental input data (including not used and rejected ones),as well as details on the evaluation procedures used to derive the tables with recommended values given in the second part.This article describes the evaluation philosophy and procedures that were implemented in the selection of specific nuclear reaction,decay and mass-spectrometer results.These input values were entered in the least-squares adjustment procedure for determining the best values for the atomic masses and their uncertainties.Calculation procedures and particularities of the AME are then described.All accepted and rejected data,including outweighed ones,are presented in a tabular format and compared with the adjusted values (obtained using the adjustment procedure).Differences with the previous AME2003 evaluation are also discussed and specific information is presented for several cases that may be of interest to various AME users.The second AME2012 article,the last one in this issue,gives a table with recommended values of atomic masses,as well as tables and graphs of derived quantities,along with the list of references used in both this AME2012 evaluation and the NUBASE2012 one (the first paper in this issue).

  18. EtherCAT协议分析

    Institute of Scientific and Technical Information of China (English)

    杨晓鸿

    2014-01-01

    <正>EtherCAT协议是德国倍福自动化有限公司(Beckhoff Automation GmbH)于2003年提出,并于2005年被定为IEC标准62407;2007年,IEC把EtherCAT协议加到工业现场总线标准61158。一、协议概述为提高通信效率以及实时性,EtherCAT协议的主要思想有两方面。简化协议,协议兼容以太网的MAC层协议,并由纯硬件完成解析,提高处理速度;而其他协议由软件

  19. Limonene ethers from tire pyrolysis oil

    Energy Technology Data Exchange (ETDEWEB)

    Stanciulescu, Maria; Ikura, Michio [CANMET Energy Technology Centre, Natural Resources Canada, 1 Haanel Drive, Ottawa, ON (Canada)

    2006-03-01

    Tire pyrolysis oil was produced by EnerVision Inc., Halifax, Canada using the continuous ablative reactor (CAR) system. The tire oil was separated by distillation into several fractions. Naphtha and limonene enriched naphtha were reacted with methanol over different catalysts. Batch experiments were carried out to separate limonene as methyl limonene ethers. Whole tire pyrolysis oil was distilled and the resulting distillates were redistilled to separate the limonene (bp about 176{sup o}C). Vacuum distillation yielded on average 25.5wt% naphtha containing 16.3wt% limonene (average). Redistillation increased the limonene concentration to approximately 32-37wt%. The conversion of limonene (mono-terpene) to limonene ethers (terpenoides) shifted the boiling point of the limonene derivatives out of the naphtha boiling range (IBP -190{sup o}C). This allowed the separation of fragrant limonene ethers from foul smelling naphtha. Alkoxylation reactions were performed mostly using methanol and acidic catalysts. The methyl ether [1-methyl-4-({alpha}-methoxy-isopropyl)-1-cyclohexene] has a boiling point of about 198{sup o}C which is higher than the end boiling point of the naphtha cut. Five heterogeneous catalysts (four zeolites and one ion exchange resin) were tested in a batch reactor. {beta}-Zeolite produced excellent results. The reaction of R-(+)-limonene with methanol in the presence of activated {beta}-zeolite yielded methyl ether, 87.5% at selectivity 89.7% with a maximum of 2h reaction time. Limonene conversion from whole naphtha to ethers was also high. (author)

  20. Mixing alcohol with energy drink (AMED) and total alcohol consumption: a systematic review and meta-analysis.

    Science.gov (United States)

    Verster, Joris C; Benson, Sarah; Johnson, Sean J; Scholey, Andrew; Alford, Chris

    2016-01-01

    It has been suggested that consuming alcohol mixed with energy drink (AMED) may increase total alcohol consumption. Aims of this systematic review and meta-analysis were (i) to compare alcohol consumption of AMED consumers with alcohol only (AO) consumers (between-group comparisons), and (ii) to examine if alcohol consumption of AMED consumers differs on AMED and AO occasions (within-subject comparisons). A literature search identified fourteen studies. Meta-analyses of between-group comparisons of N = 5212 AMED consumers and N = 12,568 AO consumers revealed that on a typical single drinking episode AMED consumers drink significantly more alcohol than AO consumers (p = 0.0001, ES = 0.536, 95%CI: 0.349 to 0.724). Meta-analyses of within-subject comparisons among N = 2871 AMED consumers revealed no significant difference in overall alcohol consumption on a typical drinking episode between AMED and AO occasions (p = 0.465, ES = -0.052, 95%CI: -0.192 to 0.088). In conclusion, between-group comparisons suggest that heavy alcohol consumption is one of the several phenotypical differences between AMED and AO consumers. Within-subject comparisons revealed, however, that AMED consumption does not increase the total amount of alcohol consumed on a single drinking episode.

  1. The AME2016 atomic mass evaluation (I). Evaluation of input data; and adjustment procedures

    Science.gov (United States)

    Huang, W. J.; Audi, G.; Wang, Meng; Kondev, F. G.; Naimi, S.; Xu, Xing

    2017-03-01

    This paper is the first of two articles (Part I and Part II) that presents the results of the new atomic mass evaluation, AME2016. It includes complete information on the experimental input data (also including unused and rejected ones), as well as details on the evaluation procedures used to derive the tables of recommended values given in the second part. This article describes the evaluation philosophy and procedures that were implemented in the selection of specific nuclear reaction, decay and mass-spectrometric results. These input values were entered in the least-squares adjustment for determining the best values for the atomic masses and their uncertainties. Details of the calculation and particularities of the AME are then described. All accepted and rejected data, including outweighted ones, are presented in a tabular format and compared with the adjusted values obtained using the least-squares fit analysis. Differences with the previous AME2012 evaluation are discussed and specific information is presented for several cases that may be of interest to AME users. The second AME2016 article gives a table with the recommended values of atomic masses, as well as tables and graphs of derived quantities, along with the list of references used in both the AME2016 and the NUBASE2016 evaluations (the first paper in this issue). AMDC: http://amdc.impcas.ac.cn/ Contents The AME2016 atomic mass evaluation (I). Evaluation of input data; and adjustment proceduresAcrobat PDF (1.2 MB) Table I. Input data compared with adjusted valuesAcrobat PDF (1.3 MB)

  2. Organization Domain Modeling (ODM): Extending systematic D-AME beyond software domains

    Energy Technology Data Exchange (ETDEWEB)

    Simos, M.A. [Organon Motives, Inc., Belmont, MA (United States)

    1996-12-31

    The emerging discipline of domain analysis, modeling, and engineering, or D-AME, has received most attention from the field of systematic software reuse, where the term {open_quotes}domain{close_quotes} usually denotes a well-scoped area of functionality within a set or class of software systems. A central challenge in D-AME research has been in defining processes and representations sufficiently general to apply in the diverse organizational and technical environments in which D-AME can make useful contribution. The systematic reuse community has established ambitious goals for what a D-AME process should address, such as the ability to support design for reuse for all products and processes of the software life cycle, and applicability beyond software domains: e.g., to domains such as business processes, product variability models, or more generally, domains of shared knowledge about particular technical areas of expertise. In practice, though, the search for generalized domain analysis processes and methods has been fraught. with difficulties. Obstacles include: adoption of a too-narrow conception of the nature of {open_quotes}domains{close_quotes}; tight coupling of D-AME process and methods with software engineering representations; and a consequent lack of understanding of the unique aspects of D-AME as a qualitative process. This paper discusses the goals for the extensibility of D-AME, the primary barriers to achieving these goals, and specific features of the Organization Domain Modeling (ODM) methodology that address these issues. ODM is structured as a core life cycle process model which is broadly applicable to diverse domains and organizational contexts. The core process is augmented by a set of supporting methods which facilitate tailorability, for example, by encapsulating commitments to specific software design representations and processes.

  3. Comb-shaped single ion conductors based on polyacrylate ethers and lithium alkyl sulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Sun Xiaoguang [Lawrence Berkeley National Laboratory, EETD, MS 62-203, One Cyclotron Road, Berkeley, CA 94720 (United States)]. E-mail: xsun@lbl.gov; Hou Jun [Lawrence Berkeley National Laboratory, EETD, MS 62-203, One Cyclotron Road, Berkeley, CA 94720 (United States); Kerr, John B. [Lawrence Berkeley National Laboratory, EETD, MS 62-203, One Cyclotron Road, Berkeley, CA 94720 (United States)]. E-mail: jbkerr@lbl.gov

    2005-01-15

    Comb-shaped single ion conductors have been synthesized by (1) sulfonation of small molecule chloroethyleneglycols, which, after ion exchange to the Li{sup +} salt were then converted to the acrylate by reaction with acryloyl chloride and copolymerized with polyethylene glycol monomethyl ether acrylate (Mn = 454, n = 8) (PAE{sub 8}-co-E{sub 3}SO{sub 3}Li); (2) sulfonation of chloride end groups grafted on to prepolymers of polyacrylate ethers (PAE{sub 8}-g-E{sub n}SO{sub 3}Li, n = 2, 3). The highest conductivity at 25 deg. C of 2.0 x 10{sup -7} S cm{sup -1} was obtained for the PAE{sub 8}-co-E{sub 3}SO{sub 3}Li with a salt concentration of EO/Li = 40. The conductivity of PAE{sub 8}-g-E{sub 3}SO{sub 3}Li is lower than that of PAE{sub 8}-co-E{sub 3}SO{sub 3}Li at similar salt concentrations, which is related to the incomplete sulfonation of the grafted polymer that leads to a lower concentration of Li{sup +}. The addition of 50 wt.% of plasticizer, PC/EMC (1/1, v/v), to PAE{sub 8}-g-E{sub 2}SO{sub 3}Li increases the ambient conductivity by three orders of magnitude, which is due to the increased ion mobility in a micro-liquid environment and an increase concentration of free ions as a result of the higher dielectric constant of the solvent. A symmetrical Li/Li cell with an electrolyte membrane consisting of 75 wt.% PC/EMC (1/1, v/v) was cycled at a current density of 100 {mu}A cm{sup -2} at 85 deg. C. The cycling profile showed no concentration polarization after a break-in period during the first few cycles, which was apparently due to reaction of the solvent at the lithium metal surface that reacted with lithium metal to form a stable SEI layer.

  4. Comb-shaped single ion conductors based on polyacrylate ethers and lithium alkyl sulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Xiao Guang Sun; Jan Hou; Kerr, J.B. [Lawrence Berkeley National Lab., CA (United States). EETD

    2005-01-15

    Comb-shaped single ion conductors have been synthesized by (1) sulfonation of small molecule chloroethyleneglycols, which, after ion exchange to the Li{sup +} salt were then converted to the acrylate by reaction with acryloyl chloride and copolymerized with polyethylene glycol monomethyl ether acrylate (Mn = 454, n = 8) (PAE{sub 8}-co-E{sub 3}SO{sub 3}Li); (2) sulfonation of chloride end groups grafted on to prepolymers of polyacrylate ethers (PAE{sub 8}-g-E{sub n}SO{sub 3}Li, n = 2, 3). The highest conductivity at 25 {sup o}C of 2.0 x {sup -7} S cm{sup -1} was obtained for the PAE{sub 8}-co-E{sub 3}SO{sub 3}Li with a salt concentration of EO/Li = 40. The conductivity of PAE{sub 8}-g-E{sub 3}SO{sub 3}Li is lower than that of PAE{sub 8}-co-E{sub 3}SO{sub 3}Li at similar salt concentrations, which is related to the incomplete sulfonation of the grafted polymer that leads to a lower concentration of Li{sup +}. The addition of 50 wt.% of plasticizer, PC/EMC (1/1, v/v), to PAE{sub 8}-g-E{sub 2}SO{sub 3}Li increases the ambient conductivity by three orders of magnitude, which is due to the increased ion mobility in a micro-liquid environment and an increase concentration of free ions as a result of the higher dielectric constant of the solvent. A symmetrical Li/Li cell with an electrolyte membrane consisting of 75 wt.% PC/EMC (1/1, v/v) was cycled at a current density of 100 {mu}A cm{sup -2} at 85 {sup o}C. The cycling profile showed no concentration polarization after a break-in period during the first few cycles, which was apparently due to reaction of the solvent at the lithium metal surface that reacted with lithium metal to form a stable SEI layer. (Author)

  5. Finkelstein Reaction in Functionalized Crown-ether Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    Xiao Hua WANG; Han Zhi WANG; Hui LIU; Yuan KOU

    2006-01-01

    Functional crown-ether ionic liquids were used as catalytic green solvents of Finkelstein reaction of 1-bromooctane and iodide. The rate and yield of the reaction were obvious improved compared with that using crown ether in water. No free crown ether loss was observed after reaction.

  6. 40 CFR 721.3435 - Butoxy-substituted ether alkane.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butoxy-substituted ether alkane. 721... Substances § 721.3435 Butoxy-substituted ether alkane. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as butoxy-substituted ether...

  7. 46 CFR 151.50-42 - Ethyl ether.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Ethyl ether. 151.50-42 Section 151.50-42 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-42 Ethyl ether. (a)(1) Gravity tanks... liquid. (g) Precautions shall be taken to prevent the contamination of ethyl ether by strong...

  8. Orphan enzymes in ether lipid metabolism.

    Science.gov (United States)

    Watschinger, Katrin; Werner, Ernst R

    2013-01-01

    Ether lipids are an emerging class of lipids which have so far not been investigated and understood in every detail. They have important roles as membrane components of e.g. lens, brain and testis, and as mediators such as platelet-activating factor. The metabolic enzymes for biosynthesis and degradation have been investigated to some extent. As most involved enzymes are integral membrane proteins they are tricky to handle in biochemical protocols. The sequence of some ether lipid metabolising enzymes has only recently been reported and other sequences still remain obscure. Defined enzymes without assigned sequence are known as orphan enzymes. One of these enzymes with uncharacterised sequence is plasmanylethanolamine desaturase, a key enzyme for the biosynthesis of one of the most abundant phospholipids in our body, the plasmalogens. This review aims to briefly summarise known functions of ether lipids, give an overview on their metabolism including the most prominent members, platelet-activating factor and the plasmalogens. A special focus is set on the description of orphan enzymes in ether lipid metabolism and on the successful strategies how four previous orphans have recently been assigned a sequence. Only one of these four was characterised by classical protein purification and sequencing, whereas the other three required alternative strategies such as bioinformatic candidate gene selection and recombinant expression or development of an inhibitor and multidimensional metabolic profiling.

  9. POLYBROMINATED DIPHENYL ETHERS IN SOUTHERN MISSISSIPPI CATFISH

    Science.gov (United States)

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in a wide variety of consumer products. Concerns surrounding these compounds are primarily due do their ubiquitous presence in the environment as well as in human tissue, such as milk, coupled with evidence indi...

  10. Ether, Luminosity and Galactic Source Counts

    CERN Document Server

    Tomaschitz, R

    1998-01-01

    An interpretation of the cosmological redshift in terms of a cosmic ether is given. We study a Robertson-Walker cosmology in which the ether is phenomenologically defined by a homogeneous and isotropic permeability tensor. The speed of light becomes so a function of cosmic time like in a dielectric medium. However, the cosmic ether is dispersion free, it does not lead to a broadening of spectral lines. Locally, in Euclidean frames, the scale factors of the permeability tensor get absorbed in the fundamental constants. Mass and charge scale with cosmic time, and so do atomic energy levels. This substantially changes the interpretation of the cosmological redshift as a Doppler shift. Photon frequencies are independent of the expansion factor; their time scaling is determined by the permeability tensor. The impact of the ether on the luminosity-distance, on the distance-redshift relation, and on galactic number counts is discussed. The Hubble constant is related to the scale factors of the metric and the permeab...

  11. Biosynthesis of archaeal membrane ether lipids

    NARCIS (Netherlands)

    Jain, Samta; Caforio, Antonella; Driessen, Arnold J. M.

    2014-01-01

    A vital function of the cell membrane in all living organism is to maintain the membrane permeability barrier and fluidity. The composition of the phospholipid bilayer is distinct in archaea when compared to bacteria and eukarya. In archaea, isoprenoid hydrocarbon side chains are linked via an ether

  12. Based Design EtherCAT Slave%基于EtherCAT的从站设计

    Institute of Scientific and Technical Information of China (English)

    文辉

    2015-01-01

    Fieldbus has become an important part of the automatic control technology, through a large number of practical experiments and testing, now widely applied. EtherCAT has good real-time capability to adapt to the small amount of data communications, and affordable, the industrial control has been widely used. However, due to EtherCAT Slave design must use a special chip, leading from the station complex hardware design, commissioning difficulties, increasing costs. In this paper, AM3358 Cortex A8 processor plus Ethernet physical layer transceiver (PHY) program, due to the integrated chip inside AM3358 Industrial communications subsystem (PRU-ICSS) EtherCAT protocol can be achieved, so long as the external PHY can become EtherCAT Slave ..%现场总线已经成为自动化控制技术重要组成部分,通过大量的实践实验与测试,如今已经获得广泛的应用。EtherCAT具有良好的实时能力,适应小数据量通信,并且价格经济,在工业控制上得到广泛的应用。但由于EtherCAT从站设计必须使用专门的芯片,导致从站的硬件设计复杂、调试困难、成本增加。文章采用AM3358 Cortex A8处理器外加以太网物理层收发器(PHY)的方案,由于AM3358片内集成工业用通信子系统(PRU-ICSS)可以实现EtherCAT协议,因此只要外加PHY就可以成为EtherCAT从站。

  13. Synthesis of poly(vinyl ether)s with perfluoroalkyl pendant groups

    NARCIS (Netherlands)

    Höpken, Jens; Möller, Martin; Lee, Myongsoo; Percec, Virgil

    1992-01-01

    2-Perfluoro(alkyl)ethyl vinyl ethers, F(CF2)nCH2CH2OCHCH2, (n = 6 or 8), were synthesized and polymerized by means of cationic initiators (HI/ZnI2 and CF3SO3H/(CH3)2S). The perfluorohexyl-substituted poly(vinyl ether) is completely amorphous. The polymer with perfluorooctyl segments shows side chain

  14. Vitamin D₃ and monomethyl fumarate enhance natural killer cell lysis of dendritic cells and ameliorate the clinical score in mice suffering from experimental autoimmune encephalomyelitis.

    Science.gov (United States)

    Al-Jaderi, Zaidoon; Maghazachi, Azzam A

    2015-11-13

    Experimental autoimmune encephalomyelitis (EAE) is a CD4⁺ T cell mediated inflammatory demyelinating disease that is induced in mice by administration of peptides derived from myelin proteins. We developed EAE in SJL mice by administration of PLP139-151 peptide. The effect of treating these mice with 1α,25-Dihydroxyvitamin D₃ (vitamin D₃), or with monomethyl fumarate (MMF) was then examined. We observed that both vitamin D₃ and MMF inhibited and/or prevented EAE in these mice. These findings were corroborated with isolating natural killer (NK) cells from vitamin D₃-treated or MMF-treated EAE mice that lysed immature or mature dendritic cells. The results support and extend other findings indicating that an important mechanism of action for drugs used to treat multiple sclerosis (MS) is to enhance NK cell lysis of dendritic cells.

  15. Preparation and characterization of monovalent ion selective cation exchange membranes based on sulphonated poly(ether ether ketone)

    NARCIS (Netherlands)

    Balster, J.H.; Krupenko, O.; Krupenko, O.; Punt, Ineke G.M.; Stamatialis, Dimitrios; Wessling, Matthias

    2005-01-01

    This paper analyses the separation properties of various commercial cation exchange membranes (CEMs) and tailor made membranes based on sulphonated poly(ether ether ketone) and poly(ether sulphone) for binary electrolyte solutions containing protons and calcium ions. All membranes are thoroughly

  16. Preparation and characterisation of monovalent ion selective cation exchange membranes based on sulphonated poly(ether ether ketone)

    NARCIS (Netherlands)

    Balster, J.; Krupenko, O.; Punt, I.G.M.; Stamatialis, D.; Wessling, M.

    2005-01-01

    This paper analyses the separation properties of various commercial cation exchange membranes (CEMs) and tailor made membranes based on sulphonated poly(ether ether ketone) and poly(ether sulphone) for binary electrolyte solutions containing protons and calcium ions. All membranes are thoroughly cha

  17. The AME2016 atomic mass evaluation (II). Tables, graphs and references

    Science.gov (United States)

    Wang, Meng; Audi, G.; Kondev, F. G.; Huang, W. J.; Naimi, S.; Xu, Xing

    2017-03-01

    This paper is the second part of the new evaluation of atomic masses, AME2016. Using least-squares adjustments to all evaluated and accepted experimental data, described in Part I, we derive tables with numerical values and graphs to replace those given in AME2012. The first table lists the recommended atomic mass values and their uncertainties. It is followed by a table of the influences of data on primary nuclides, a table of various reaction and decay energies, and finally, a series of graphs of separation and decay energies. The last section of this paper lists all references of the input data used in the AME2016 and the NUBASE2016 evaluations (first paper in this issue). AMDC: http://amdc.impcas.ac.cn/ Contents The AME2016 atomic mass evaluation (II). Tables, graphs and referencesAcrobat PDF (293 KB) Table I. The 2016 Atomic mass tableAcrobat PDF (273 KB) Table II. Influences on primary nuclidesAcrobat PDF (160 KB) Table III. Nuclear-reaction and separation energiesAcrobat PDF (517 KB) Graphs of separation and decay energiesAcrobat PDF (589 KB) References used in the AME2016 and the NUBASE2016 evaluationsAcrobat PDF (722 KB)

  18. Tween as a Substitute for Diethyl Ether in the Formalin-Ether Sedimentation Technique

    Directory of Open Access Journals (Sweden)

    NA Ahmadi

    2007-10-01

    Full Text Available Background: Tween as a substitute for diethyl ether in the formalin-ether sedimentation technique was evaluated for para­site detection.Methods: Fresh fecal material free of parasites with 10% formalin to prepare standardized specimen was thoroughly pooled. This specimen was divided into 5 equal portions; one was without infection, and each of the others was individually seeded with Entamoeba coli, and Giardia lamblia cysts, ova of Ascaris lumbericoides, and Hymenolepis nana. Six hundred and eighty four slides including 228 stool samples for each of formalin-tween, formalin-ether and direct wet mount proce­dures were examined.Results: The sensitivity of above mentioned procedures were computed 72.1%, 55% and 30 %; their negative predictive value were 69.3%, 58.3% and 47.3%; and their false negative error rate were 27.9%, 45% and 70%, respectively. There were no false-positive results among the 264 specimens previously identified as negative for the presence of intestinal para­sites. Therefore, specificity for each technique was 100%.Conclusion: In the range of our study, formalin-tween method proved to be equivalent to or better than formalin-ether tech­nique in concentrating parasite eggs, and cysts, as well as in maintaining characteristic morphology. Tween is more stable, safer, cheaper, and less flammable than that of ether; and promises to be a useful alternative to ether.

  19. Processing Earth Observing images with Ames Stereo Pipeline

    Science.gov (United States)

    Beyer, R. A.; Moratto, Z. M.; Alexandrov, O.; Fong, T.; Shean, D. E.; Smith, B. E.

    2013-12-01

    ICESat with its GLAS instrument provided valuable elevation measurements of glaciers. The loss of this spacecraft caused a demand for alternative elevation sources. In response to that, we have improved our Ames Stereo Pipeline (ASP) software (version 2.1+) to ingest satellite imagery from Earth satellite sources in addition to its support of planetary missions. This enables the open source community a free method to generate digital elevation models (DEM) from Digital Globe stereo imagery and alternatively other cameras using RPC camera models. Here we present details of the software. ASP is a collection of utilities written in C++ and Python that implement stereogrammetry. It contains utilities to manipulate DEMs, project imagery, create KML image quad-trees, and perform simplistic 3D rendering. However its primary application is the creation of DEMs. This is achieved by matching every pixel between the images of a stereo observation via a hierarchical coarse-to-fine template matching method. Matched pixels between images represent a single feature that is triangulated using each image's camera model. The collection of triangulated features represents a point cloud that is then grid resampled to create a DEM. In order for ASP to match pixels/features between images, it requires a search range defined in pixel units. Total processing time is proportional to the area of the first image being matched multiplied by the area of the search range. An incorrect search range for ASP causes repeated false positive matches at each level of the image pyramid and causes excessive processing times with no valid DEM output. Therefore our system contains automatic methods for deducing what the correct search range should be. In addition, we provide options for reducing the overall search range by applying affine epipolar rectification, homography transform, or by map projecting against a prior existing low resolution DEM. Depending on the size of the images, parallax, and image

  20. The AME2016 atomic mass evaluation (II). Tables, graphs and references

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Meng; Audi, G.; Kondev, F. G.; Huang, W. J.; Naimi, S.; Xu, Xing

    2017-03-01

    This paper is the second part of the new evaluation of atomic masses, Ame2016. Using least-squares adjustments to all evaluated and accepted experimental data, described in Part I, we derive tables with numerical values and graphs to replace those given in Ame2012. The first table lists the recommended atomic mass values and their uncertainties. It is followed by a table of the influences of data on primary nuclides, a table of various reaction and decay energies, and finally, a series of graphs of separation and decay energies. The last section of this paper lists all references of the input data used in the Ame2016 and the Nubase2016 evaluations (first paper in this issue). Amdc: http://amdc.impcas.ac.cn/

  1. Study of optical techniques for the Ames unitary wind tunnels. Part 3: Angle of attack

    Science.gov (United States)

    Lee, George

    1992-01-01

    A review of optical sensors that are capable of accurate angle of attack measurements in wind tunnels was conducted. These include sensors being used or being developed at NASA Ames and Langley Research Centers, Boeing Airplane Company, McDonald Aircraft Company, Arnold Engineering Development Center, National Aerospace Laboratory of the Netherlands, National Research Council of Canada, and the Royal Aircraft Establishment of England. Some commercial sensors that may be applicable to accurate angle measurements were also reviewed. It was found that the optical sensor systems were based on interferometers, polarized light detector, linear or area photodiode cameras, position sensing photodetectors, and laser scanners. Several of the optical sensors can meet the requirements of the Ames Unitary Plan Wind Tunnel. Two of these, the Boeing interferometer and the Complere lateral effect photodiode sensors are being developed for the Ames Unitary Plan Wind Tunnel.

  2. Induction of Monocular Stereopsis by Altering Focus Distance: A Test of Ames's Hypothesis.

    Science.gov (United States)

    Vishwanath, Dhanraj

    2016-03-01

    Viewing a real three-dimensional scene or a stereoscopic image with both eyes generates a vivid phenomenal impression of depth known as stereopsis. Numerous reports have highlighted the fact that an impression of stereopsis can be induced in the absence of binocular disparity. A method claimed by Ames (1925) involved altering accommodative (focus) distance while monocularly viewing a picture. This claim was tested on naïve observers using a method inspired by the observations of Gogel and Ogle on the equidistance tendency. Consistent with Ames's claim, most observers reported that the focus manipulation induced an impression of stereopsis comparable to that obtained by monocular-aperture viewing.

  3. A Survey of Knowledge Management Research & Development at NASA Ames Research Center

    Science.gov (United States)

    Keller, Richard M.; Clancy, Daniel (Technical Monitor)

    2002-01-01

    This chapter catalogs knowledge management research and development activities at NASA Ames Research Center as of April 2002. A general categorization scheme for knowledge management systems is first introduced. This categorization scheme divides knowledge management capabilities into five broad categories: knowledge capture, knowledge preservation, knowledge augmentation, knowledge dissemination, and knowledge infrastructure. Each of nearly 30 knowledge management systems developed at Ames is then classified according to this system. Finally, a capsule description of each system is presented along with information on deployment status, funding sources, contact information, and both published and internet-based references.

  4. Study of optical techniques for the Ames unitary wind tunnel, part 7

    Science.gov (United States)

    Lee, George

    1993-01-01

    A summary of optical techniques for the Ames Unitary Plan wind tunnels are discussed. Six optical techniques were studied: Schlieren, light sheet and laser vapor screen, angle of attack, model deformation, infrared imagery, and digital image processing. The study includes surveys and reviews of wind tunnel optical techniques, some conceptual designs, and recommendations for use of optical methods in the Ames Unitary Plan wind tunnels. Particular emphasis was placed on searching for systems developed for wind tunnel use and on commercial systems which could be readily adapted for wind tunnels. This final report is to summarize the major results and recommendations.

  5. Inhibition of diethyl ether degradation in Rhodococcus sp. strain DEE5151 by glutaraldehyde and ethyl vinyl ether.

    Science.gov (United States)

    Kim, Yong-Hak; Engesser, Karl-Heinrich

    2005-02-15

    Alkyl ether-degrading Rhodococcus sp. strain DEE5151, isolated from activated sewage sludge, has an activity for the oxidation of a variety of alkyl ethers, aralkyl ethers and dibenzyl ether. The whole cell activity for diethyl ether oxidation was effectively inhibited by 2,3-dihydrofurane, ethyl vinyl ether and glutaraldehyde. Glutaraldehyde of less than 30 microM inhibited the activity by a competitive manner with the inhibition constant, K(I) of 7.07+/-1.36 microM. The inhibition type became mixed at higher glutaraldehyde concentrations >30 microM, probably due to the inactivation of the cell activity by the Schiff-base formation. Structurally analogous ethyl vinyl ether inhibited the diethyl ether oxidation activity in a mixed manner with decreasing the apparent maximum oxidation rate, v(max)(app), and increasing the apparent Michaelis-Menten constant, K(M)(app). The mixed type inhibition by ethyl vinyl ether seemed to be introduced not only by the structure similarity with diethyl ether, but also by the reactivity of the vinyl ether with cellular components in the whole cell system.

  6. PMARC_12 - PANEL METHOD AMES RESEARCH CENTER, VERSION 12

    Science.gov (United States)

    Ashby, D. L.

    1994-01-01

    Panel method computer programs are software tools of moderate cost used for solving a wide range of engineering problems. The panel code PMARC_12 (Panel Method Ames Research Center, version 12) can compute the potential flow field around complex three-dimensional bodies such as complete aircraft models. PMARC_12 is a well-documented, highly structured code with an open architecture that facilitates modifications and the addition of new features. Adjustable arrays are used throughout the code, with dimensioning controlled by a set of parameter statements contained in an include file; thus, the size of the code (i.e. the number of panels that it can handle) can be changed very quickly. This allows the user to tailor PMARC_12 to specific problems and computer hardware constraints. In addition, PMARC_12 can be configured (through one of the parameter statements in the include file) so that the code's iterative matrix solver is run entirely in RAM, rather than reading a large matrix from disk at each iteration. This significantly increases the execution speed of the code, but it requires a large amount of RAM memory. PMARC_12 contains several advanced features, including internal flow modeling, a time-stepping wake model for simulating either steady or unsteady (including oscillatory) motions, a Trefftz plane induced drag computation, off-body and on-body streamline computations, and computation of boundary layer parameters using a two-dimensional integral boundary layer method along surface streamlines. In a panel method, the surface of the body over which the flow field is to be computed is represented by a set of panels. Singularities are distributed on the panels to perturb the flow field around the body surfaces. PMARC_12 uses constant strength source and doublet distributions over each panel, thus making it a low order panel method. Higher order panel methods allow the singularity strength to vary linearly or quadratically across each panel. Experience has shown

  7. Emergent gravity and ether-drift experiments

    CERN Document Server

    Consoli, M

    2009-01-01

    In principle, ether-drift experiments could distinguish phenomenologically emergent-gravity approaches, where an effective curvature emerges from hydrodynamic distortions of the same physical, flat-space vacuum, from the more conventional scenario where curvature is considered a fundamental property of space-time down to extremely small length scales and the speed of light represents a universal constant. From an experimental point of view, in this particular context, besides time modulations that might be induced by the Earth's rotation (and its orbital revolution), one should also consider the possibility of random fluctuations of the signal. These might reflect the stochastic nature of the underlying 'quantum ether' and be erroneously interpreted as mere instrumental noise. To test the present interpretation, we have extracted the mean amplitude of the signal from various experiments with different systematics, operating both at room temperature and in the cryogenic regime. They all give the same consisten...

  8. Synthesis of New Liquid Crystalline Diglycidyl Ethers

    Directory of Open Access Journals (Sweden)

    Issam Ahmed Mohammed

    2012-01-01

    Full Text Available The phenolic Schiff bases I–VI were synthesized by condensation reactions between various diamines, namely o-dianisidine, o-tolidine and ethylenediamine with vanillin or p-hydroxybenzaldehyde and subsequent reactions between these phenolic Schiff bases and epichlorohydrin to produce new diglycidyl ethers Ia–VIa. The structures of these compounds were confirmed by CHN, FT-IR, 1H-NMR, and 13C-NMR spectroscopy. Their thermotropic liquid crystalline behavior was studied using differential scanning calorimetry (DSC and polarizing optical microscopy (POM. All the diglycidyl ethers prepared exhibit nematic mesophases, except for Va and VIa, which did not show any transition mesophases, but simply flow to liquids.

  9. Fluoroalkylation of aryl ether perfluorocyclobutyl polymers

    OpenAIRE

    Ligon, Clark; Ameduri, Bruno; Boutevin, Bernard; Smith, Dennis

    2008-01-01

    International audience; Post functionalization of aryl ether perfluorocyclobutyl (PFCB) polymers with fluoroalkyl side chains was accomplished with Umemoto's FITS reagents. The fluoroalkylated PFCB polymers (20 % functionalized) showed increases in both hydrophobicity and oleophobicity. Static contact angle for hexadecane was increased after fluoroalkylation from 0° to greater than 30° for the two PFCB polymers tested. Increased oil repellency makes these materials potential candidates for va...

  10. Catalytic intermolecular hydroamination of vinyl ethers.

    Science.gov (United States)

    Pahadi, Nirmal K; Tunge, Jon A

    2009-12-01

    This manuscript details the development of a palladium-catalyzed hydroamination of vinyl ethers. It is proposed that palladium catalyzes the hydroamination via Bronsted base catalysis, where palladium is protonated by the relatively acidic sulfonamide to generate a palladium hydride as well as the active anionic sulfonamide nucleophile. Thus, this process is distinct from known palladium-catalyzed hydroaminations of styrene derivatives that utilize less acidic amines.

  11. Converting biogenic dimethyl ether into fuels

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Michael; Otto, Thomas N.; Dinjus, Eckhard [Karlsruher Institut fuer Technologie (KIT), Eggenstein-Leopoldshafen (Germany). Inst. fuer Katalyseforschung und -technologie (IKFT)

    2013-06-01

    In the seventies, the MtG (''methanol-to-gasoline'') process was an alternative to the Fischer-Tropsch process developed in the thirties of the past century. The MtG process is performed with dimethyl ether (DME) as an intermediate. Hydrocarbons (C{sub 1}-C{sub 10}) directly synthesised via DME with the assistance of zeolites as catalysts offers considerable advantages over the MtG process. Zeolites play an important role in the production of biomass-based fuels from synthesis gas. Known and mature technologies exist for synthesis gas of fossil origin (coal, natural gas, petroleum). These established technologies may also be transferred to synthesis gas of biogenous origin. Dimethyl ether produced from biomass-based synthesis gas is a central intermediate product. In the MtG and DtG (''dimethyl ether-to-gasoline'') process H-ZSM-5 zeolites are of major significance. Modification of H-ZSM-5 catalysts is the basis of customized product synthesis. Hierarchic structures of zeolites change the diffusion properties of the crystals and can help to achieve a more selective range of products. (orig.)

  12. Nikola Tesla, the Ether and his Telautomaton

    Science.gov (United States)

    Milar, Kendall

    2014-03-01

    In the nineteenth century physicists' understanding of the ether changed dramatically. New developments in thermodynamics, energy physics, and electricity and magnetism dictated new properties of the ether. These have traditionally been examined from the perspective of the scientists re-conceptualizing the ether. However Nikola Tesla, a prolific inventor and writer, presents a different picture of nineteenth century physics. Alongside the displays that showcased his inventions he presented alternative interpretations of physical, physiological and even psychical research. This is particularly evident in his telautomaton, a radio remote controlled boat. This invention and Tesla's descriptions of it showcase some of his novel interpretations of physical theories. He offered a perspective on nineteenth century physics that focused on practical application instead of experiment. Sometimes the understanding of physical theories that Tesla reached was counterproductive to his own inventive work; other times he offered new insights. Tesla's utilitarian interpretation of physical theories suggests a more scientifically curious and invested inventor than previously described and a connection between the scientific and inventive communities.

  13. Mutagenic Potential of DIGL-RO Solid Propellant in the Ames Salmonella/ Mammalian Microsome Mutagenicity Test

    Science.gov (United States)

    1988-09-01

    303913 11. TITLE (Include Security Clasification ) Mutagenic Potential of DIGL-RP Solid Propellant in the Ames Salmonella/Mammalian Microsome Mutagenicity...mg protein /plate. After all the ingredients were added, the top agar was mixed, then overlaid on MGA plates. These plates contained 2% glucose and

  14. A survey of planning and scheduling research at the NASA Ames Research Center

    Science.gov (United States)

    Zweben, Monte

    1989-01-01

    NASA Ames Research Center has a diverse program in planning and scheduling. Some research projects as well as some applications are highlighted. Topics addressed include machine learning techniques, action representations and constraint-based scheduling systems. The applications discussed are planetary rovers, Hubble Space Telescope scheduling, and Pioneer Venus orbit scheduling.

  15. Satellite communications provisions on NASA Ames instrumented aircraft platforms for Earth science research/applications

    Science.gov (United States)

    Shameson, L.; Brass, J. A.; Hanratty, J. J.; Roberts, A. C.; Wegener, S. S.

    1995-01-01

    Earth science activities at NASA Ames are research in atmospheric and ecosystem science, development of remote sensing and in situ sampling instruments, and their integration into scientific research platform aircraft. The use of satellite communications can greatly extend the capability of these agency research platform aircraft. Current projects and plans involve satellite links on the Perseus UAV and the ER-2 via TDRSS and a proposed experiment on the NASA Advanced Communications Technology Satellite. Provisions for data links on the Perseus research platform, via TDRSS S-band multiple access service, have been developed and are being tested. Test flights at Dryden are planned to demonstrate successful end-to-end data transfer. A Unisys Corp. airborne satcom STARLink system is being integrated into an Ames ER-2 aircraft. This equipment will support multiple data rates up to 43 Mb/s each via the TDRS S Ku-band single access service. The first flight mission for this high-rate link is planned for August 1995. Ames and JPL have proposed an ACTS experiment to use real-time satellite communications to improve wildfire research campaigns. Researchers and fire management teams making use of instrumented aircraft platforms at a prescribed burn site will be able to communicate with experts at Ames, the U.S. Forest Service, and emergency response agencies.

  16. Research and technology activities at Ames Research Center's Biomedical Research Division

    Science.gov (United States)

    Martello, N.

    1985-01-01

    Various research and technology activities at Ames Research Center's Biomedical Research Division are described. Contributions to the Space Administration's goals in the life sciences include descriptions of research in operational medicine, cardiovascular deconditioning, motion sickness, bone alterations, muscle atrophy, fluid and electrolyte changes, radiation effects and protection, behavior and performance, gravitational biology, and life sciences flight experiments.

  17. Mutagenic and antimutagenic activities of bioflavonoids and structural analogues in the Ames/Salmonella test

    NARCIS (Netherlands)

    Mohn GR; Van der Stel JJ; Stavenuiter JFC; Hamzink MRJ; Kreijl CF; LEO; LBO

    1996-01-01

    The mutagenic and antimutagenic properties of bioflavonoids were determined in the bacterial mutagenicity test of Ames, using Salmonella typhimurium strains TA98 and TA100. The decreasing order of mutagenic activity found in both strains was quercetin>myricetin-kaempferol>morin hydrate. The compound

  18. The NASA Ames Polycyclic Aromatic Hydrocarbon Infrared Spectroscopic Database : The Computed Spectra

    NARCIS (Netherlands)

    Bauschlicher, C. W.; Boersma, C.; Ricca, A.; Mattioda, A. L.; Cami, J.; Peeters, E.; de Armas, F. Sanchez; Saborido, G. Puerta; Hudgins, D. M.; Allamandola, L. J.

    2010-01-01

    The astronomical emission features, formerly known as the unidentified infrared bands, are now commonly ascribed to polycyclic aromatic hydrocarbons (PAHs). The laboratory experiments and computational modeling done at the NASA Ames Research Center to create a collection of PAH IR spectra relevant t

  19. The NASA Ames Polycyclic Aromatic Hydrocarbon Infrared Spectroscopic Database: The Computed Spectra

    NARCIS (Netherlands)

    Bauschlicher, C. W.; Boersma, C.; Ricca, A.; Mattioda, A. L.; Cami, J.; Peeters, E.; Sánchez de Armas, F.; Puerta Saborido, G.; Hudgins, D. M.; Allamandola, L. J.

    2010-01-01

    The astronomical emission features, formerly known as the unidentified infrared bands, are now commonly ascribed to polycyclic aromatic hydrocarbons (PAHs). The laboratory experiments and computational modeling done at the NASA Ames Research Center to create a collection of PAH IR spectra relevant t

  20. Expression of oxidative phosphorylation components in mitochondria of long-living Ames dwarf mice

    Science.gov (United States)

    Reduced signaling of the growth hormone (GH)/insulin-like growth factor-1(IGF-1) pathway is associated with extended life span in several species. Ames dwarf mice are GH and IGF-1 deficient and live 50-68% longer than wild type littermates (males and females, respectively). Previously, we have shown...

  1. The NASA Ames Polycyclic Aromatic Hydrocarbon Infrared Spectroscopic Database : The Computed Spectra

    NARCIS (Netherlands)

    Bauschlicher, C. W.; Boersma, C.; Ricca, A.; Mattioda, A. L.; Cami, J.; Peeters, E.; de Armas, F. Sanchez; Saborido, G. Puerta; Hudgins, D. M.; Allamandola, L. J.

    The astronomical emission features, formerly known as the unidentified infrared bands, are now commonly ascribed to polycyclic aromatic hydrocarbons (PAHs). The laboratory experiments and computational modeling done at the NASA Ames Research Center to create a collection of PAH IR spectra relevant

  2. The NASA Ames Polycyclic Aromatic Hydrocarbon Infrared Spectroscopic Database: The Computed Spectra

    NARCIS (Netherlands)

    Bauschlicher, C. W.; Boersma, C.; Ricca, A.; Mattioda, A. L.; Cami, J.; Peeters, E.; Sánchez de Armas, F.; Puerta Saborido, G.; Hudgins, D. M.; Allamandola, L. J.

    2010-01-01

    The astronomical emission features, formerly known as the unidentified infrared bands, are now commonly ascribed to polycyclic aromatic hydrocarbons (PAHs). The laboratory experiments and computational modeling done at the NASA Ames Research Center to create a collection of PAH IR spectra relevant t

  3. AME - Asteroseismology Made Easy. Estimating stellar properties by use of scaled models

    CERN Document Server

    Lundkvist, M; Aguirre, V Silva

    2014-01-01

    We present a new method to obtain stellar properties for stars exhibiting solar-like oscillations in an easy, fast, and transparent way. The method, called Asteroseismology Made Easy (AME), can determine stellar masses, mean-densities, radii, and surface gravities, as well as estimate ages. In this writing we present AME as a visual and powerful tool which could be useful; in particular in the light of the large number of exoplanets being found. AME consists of a set of figures from which the stellar parameters are deduced. These figures are made from a grid of stellar evolutionary models that cover masses ranging from 0.7 Msun to 1.6 Msun in steps of 0.1 Msun and metallicities in the interval -0.3 dex <= [Fe/H] <= +0.3 dex in increments of 0.1 dex. The stellar evolutionary models are computed using the Modules for Experiments in Stellar Astrophysics (MESA) code with simple input physics. We have compared the results from AME with results for three groups of stars; stars with radii determined from inter...

  4. From ether theory to ether theology: Oliver Lodge and the physics of immortality.

    Science.gov (United States)

    Raia, Courtenay Grean

    2007-01-01

    This article follows the development of physicist Oliver Lodge's religio-scientific worldview, beginning with his reticent attraction to metaphysics in the early 1880s to the full formulation of his "ether theology" in the late 1890s. Lodge undertook the study of psychical phenomena such as telepathy, telekinesis, and "ectoplasm" to further his scientific investigations of the ether, speculating that electrical and psychical manifestations were linked phenomena that described the deeper underlying structures of the universe, beneath and beyond matter. For Lodge, to fully understand the ether was to force from the universe an ultimate Revelation, and psychical research, as the most modern and probatory science, was poised to replace religion as the means of that disclosure. (c) 2007 Wiley Periodicals, Inc.

  5. Synthesis of Diaryl Ethers, Diaryl Sulfides, Heteroaryl Ethers and Heteroaryl Sulfides under Microwave Heating

    Institute of Scientific and Technical Information of China (English)

    LI,Feng; ZOU,Jiong; WANG,Quan-Rui; TAO,Feng-Gang

    2004-01-01

    @@ Diaryl ether moiety is found in a pool of naturally occurring and medicinally important compounds.[1] As a consequent, considerable efforts have been devoted to the assembly of this framework.[2] Recently, we have developed a microwave heating version of the synthesis of diaryl ethers as well as aryl sulfides. Under our conditions, even the extremely electron-poor 4-nitrophenol works well and its reaction with 1-halo-4-nitrobenzenes produces 4-(nitrophenoxy)-benzonitriles in satisfactory yield. The scope of the present protocol has been expanded to hydroxylated six-membered heterocycles as well as 2-pyrimidinethiol with mildly activated aryl halides, affording heteroaryl ethers and respectively sulfides. The advantages of the present method include the wide substrate scope, no use of any metal catalysts, the ease of product isolation and high yields.

  6. Cultivating a Grassroots Aerospace Innovation Culture at NASA Ames Research Center

    Science.gov (United States)

    D'Souza, Sarah; Sanchez, Hugo; Lewis, Ryan

    2017-01-01

    This paper details the adaptation of specific 'knowledge production' methods to implement a first of its kind, grassroots event that provokes a cultural change in how the NASA Ames civil servant community engages in the creation and selection of innovative ideas. Historically, selection of innovative proposals at NASA Ames Research Center is done at the highest levels of management, isolating the views and perspectives of the larger civil servant community. Additionally, NASA innovation programs are typically open to technical organizations and do not engage non-technical organizations to bring forward innovative processes/business practices. Finally, collaboration on innovative ideas and associated solutions tend to be isolated to organizational silos. In this environment, not all Ames employees feel empowered to innovate and opportunities for employee collaboration are limited. In order to address these issues, the 'innovation contest' method was adapted to create the NASA Ames Innovation Fair, a unique, grassroots innovation opportunity for the civil servant community. The Innovation Fair consisted of a physical event with a virtual component. The physical event provided innovators the opportunity to collaborate and pitch their innovations to the NASA Ames community. The civil servant community then voted for the projects that they viewed as innovative and would contribute to NASA's core mission, making this event a truly grassroots effort. The Innovation Fair website provided a location for additional knowledge sharing, discussion, and voting. On March 3rd, 2016, the 'First Annual NASA Ames Innovation Fair' was held with 49 innovators and more than 300 participants collaborating and/or voting for the best innovations. Based on the voting results, seven projects were awarded seed funding for projects ranging from innovative cost models to innovations in aerospace technology. Surveys of both innovators and Fair participants show the Innovation Fair was successful

  7. Comparison of Properties among Dendritic and Hyperbranched Poly(ether ether ketone)s and Linear Poly(ether ketone)s.

    Science.gov (United States)

    Morikawa, Atsushi

    2016-02-16

    Poly(ether ether ketone) dendrimers and hyperbranched polymers were prepared from 3,5-dimethoxy-4'-(4-fluorobenzoyl)diphenyl ether and 3,5-dihydroxy-4'-(4-fluorobenzoyl)diphenyl ether through aromatic nucleophilic substitution reactions. 1-(tert-Butyldimethylsiloxy)-3,5-bis(4-fluorobenzoyl)benzene was polycondensed with bisphenols, followed by cleavage of the protective group to form linear poly(ether ketone)s having the same hydroxyl groups in the side chains as the chain ends of the dendrimer and hyperbranched polymers. Their properties, such as solubilities, reduced viscosities, and thermal properties, were compared with one another. Similar comparisons were also carried out among the corresponding methoxy group polymers, and the size of the molecules was shown to affect the properties.

  8. 76 FR 38026 - Diethylene Glycol Mono Butyl Ether; Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2011-06-29

    ... butyl ether, also a glycol ether differing in only one ethyl group from DEGBE. These data were used to... monobutyl ether, also a glycol ether differing only in one ethyl group. This data was used to assess the... AGENCY 40 CFR Part 180 Diethylene Glycol Mono Butyl Ether; Exemption From the Requirement of a...

  9. Azidated Ether-Butadiene-Ether Block Copolymers as Binders for Solid Propellants

    Science.gov (United States)

    Cappello, Miriam; Lamia, Pietro; Mura, Claudio; Polacco, Giovanni; Filippi, Sara

    2016-07-01

    Polymeric binders for solid propellants are usually based on hydroxyl-terminated polybutadiene (HTPB), which does not contribute to the overall energy output. Azidic polyethers represent an interesting alternative but may have poorer mechanical properties. Polybutadiene-polyether copolymers may combine the advantages of both. Four different ether-butadiene-ether triblock copolymers were prepared and azidated starting from halogenated and/or tosylated monomers using HTPB as initiator. The presence of the butadiene block complicates the azidation step and reduces the storage stability of the azidic polymer. Nevertheless, the procedure allows modifying the binder properties by varying the type and lengths of the energetic blocks.

  10. Investigating the Mutagenic Effects of Three Commonly Used Pulpotomy Agents Using the Ames Test

    Directory of Open Access Journals (Sweden)

    Mohammad Samiei

    2015-03-01

    Full Text Available Purpose: The mutagenic potency of materials used in dentistry is of great concern. The Ames test is a bacterial reverse mutation assay, which is used to determine the mutagenicity potential of chemicals. In this study, the Ames test was used to compare mutagenic effects of three pulpotomy agents, namely, CEM cement, formocresol and ferric sulfate. Methods: TA100 strain of Salmonella typhimurium was used to evaluate mutagenicity of different concentrations of pulpotomy materials in the presence and absence of enzymatic system found in rat liver S9 fraction. Negative controls were 1% dimethyl sulfoxide and water. The positive controls were sodium azide and 2-aminoanthracene. The number of colonies per plate was counted. The material was regarded mutagenic if the number of histidine revertant colonies was twice or more than the spontaneous revertant colonies (Ames mutagenicity ratio. Results: Ferric sulfate was found mutagenic in the concentrations prepared by addition of 50 μL of its 1 in 100 and 1 in 1000 times diluted solutions to the culture medium in the absence of S9 fraction (Ames test ratios of 2.8 and 2.2, respectively. Formocresol showed strong toxicity toward TA100 strain of S. typhimurium up to the concentration as low achieved using 1000 times diluted solution of the original preparation, particularly in the presence of S9 fraction. Ames assay failed to detect significant reverse mutations in all the concentrations of CEM cement. Conclusion: In contrast to formocresol and ferric sulfate, CEM cement is a less toxic and non-mutagenic agent.

  11. Investigating the Mutagenic Effects of Three Commonly Used Pulpotomy Agents Using the Ames Test

    Science.gov (United States)

    Samiei, Mohammad; Asgary, Saeed; Farajzadeh, Malak; Bargahi, Nasrin; Abdolrahimi, Majid; Kananizadeh, Usef; Dastmalchi, Siavoush

    2015-01-01

    Purpose: The mutagenic potency of materials used in dentistry is of great concern. The Ames test is a bacterial reverse mutation assay, which is used to determine the mutagenicity potential of chemicals. In this study, the Ames test was used to compare mutagenic effects of three pulpotomy agents, namely, CEM cement, formocresol and ferric sulfate. Methods: TA100 strain of Salmonella typhimurium was used to evaluate mutagenicity of different concentrations of pulpotomy materials in the presence and absence of enzymatic system found in rat liver S9 fraction. Negative controls were 1% dimethyl sulfoxide and water. The positive controls were sodium azide and 2-aminoanthracene. The number of colonies per plate was counted. The material was regarded mutagenic if the number of histidine revertant colonies was twice or more than the spontaneous revertant colonies (Ames mutagenicity ratio). Results: Ferric sulfate was found mutagenic in the concentrations prepared by addition of 50 µL of its 1 in 100 and 1 in 1000 times diluted solutions to the culture medium in the absence of S9 fraction (Ames test ratios of 2.8 and 2.2, respectively). Formocresol showed strong toxicity toward TA100 strain of S. typhimurium up to the concentration as low achieved using 1000 times diluted solution of the original preparation, particularly in the presence of S9 fraction. Ames assay failed to detect significant reverse mutations in all the concentrations of CEM cement. Conclusion: In contrast to formocresol and ferric sulfate, CEM cement is a less toxic and non-mutagenic agent. PMID:25789229

  12. AMES Stereo Pipeline Derived DEM Accuracy Experiment Using LROC-NAC Stereopairs and Weighted Spatial Dependence Simulation for Lunar Site Selection

    Science.gov (United States)

    Laura, J. R.; Miller, D.; Paul, M. V.

    2012-03-01

    An accuracy assessment of AMES Stereo Pipeline derived DEMs for lunar site selection using weighted spatial dependence simulation and a call for outside AMES derived DEMs to facilitate a statistical precision analysis.

  13. Phenolic ethers in the organic polymer of the Murchison meteorite

    Science.gov (United States)

    Hayatsu, R.; Winans, R. E.; Scott, R. G.; McBeth, R. L.; Moore, L. P.; Studier, M. H.

    1980-03-01

    Results of the oxidation of the organic polymer of the Murchison meteorite with alkaline cupric oxide, a mild-oxidant specific for cleaving ether linkages, are reported. Qualitative analyses by gas chromatography-mass spectrometry, solid-probe mass spectrometry and high-resolution mass spectrometry reveal the presence of large amounts of meta-hydroxybenzoic acid and 3-hydroxy-1,5-benzenedicarboxylic acid, along with seven phenolic acids, in the oxidized solution, indicating the presence of phenolic ethers and of aryl alkyl ethers having no nuclear hydroxy group in the meteorite. The formation of phenolic ethers in the solar nebula by Fischer-Tropsch type reactions is then discussed.

  14. Alcohol dehydration: Mechanism of ether formation using an alumina catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Shi, B.; Davis, B.H. [Univ. of Kentucky, Lexington, KY (United States)

    1995-12-01

    Ether formation during the dehydration of secondary alcohols, namely, 2-butanol, 3-pentanol, and 1-cyclopentylethanol, was investigated. Using the proper reaction conditions, the yield of di-2-butyl ether during the dehydration of 2-butanol on alumina can be as high as 40%. That ether is formed by adding an alcohol to the alkene is ruled out by the results from deuterium tracer studies. Results from experiments using S(+)- 2-butanol suggest that the formation of di-2-butyl ether occurs by a S{sub N}2-type mechanism. 33 refs., 5 figs., 3 tabs.

  15. Both H4K20 mono-methylation and H3K56 acetylation mark transcription-dependent histone turnover in fission yeast

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Hanna [Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Kwon, Chang Seob [Department of Chemistry and Biology, Korea Science Academy of KAIST, Busan, 614-822 (Korea, Republic of); Choi, Yoonjung, E-mail: jjungii@kaist.ac.kr [Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of); Lee, Daeyoup, E-mail: daeyoup@kaist.ac.kr [Department of Biological Sciences, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 34141 (Korea, Republic of)

    2016-08-05

    Nucleosome dynamics facilitated by histone turnover is required for transcription as well as DNA replication and repair. Histone turnover is often associated with various histone modifications such as H3K56 acetylation (H3K56Ac), H3K36 methylation (H3K36me), and H4K20 methylation (H4K20me). In order to correlate histone modifications and transcription-dependent histone turnover, we performed genome wide analyses for euchromatic regions in G2/M-arrested fission yeast. The results show that transcription-dependent histone turnover at 5′ promoter and 3′ termination regions is directly correlated with the occurrence of H3K56Ac and H4K20 mono-methylation (H4K20me1) in actively transcribed genes. Furthermore, the increase of H3K56Ac and H4K20me1 and antisense RNA production was observed in the absence of the histone H3K36 methyltransferase Set2 and histone deacetylase complex (HDAC) that are involved in the suppression of histone turnover within the coding regions. These results together indicate that H4K20me1 as well as H3K56Ac are bona fide marks for transcription-dependent histone turnover in fission yeast.

  16. Developmental Defects of Caenorhabditis elegans Lacking Branched-chain α-Ketoacid Dehydrogenase Are Mainly Caused by Monomethyl Branched-chain Fatty Acid Deficiency.

    Science.gov (United States)

    Jia, Fan; Cui, Mingxue; Than, Minh T; Han, Min

    2016-02-01

    Branched-chain α-ketoacid dehydrogenase (BCKDH) catalyzes the critical step in the branched-chain amino acid (BCAA) catabolic pathway and has been the focus of extensive studies. Mutations in the complex disrupt many fundamental metabolic pathways and cause multiple human diseases including maple syrup urine disease (MSUD), autism, and other related neurological disorders. BCKDH may also be required for the synthesis of monomethyl branched-chain fatty acids (mmBCFAs) from BCAAs. The pathology of MSUD has been attributed mainly to BCAA accumulation, but the role of mmBCFA has not been evaluated. Here we show that disrupting BCKDH in Caenorhabditis elegans causes mmBCFA deficiency, in addition to BCAA accumulation. Worms with deficiency in BCKDH function manifest larval arrest and embryonic lethal phenotypes, and mmBCFA supplementation suppressed both without correcting BCAA levels. The majority of developmental defects caused by BCKDH deficiency may thus be attributed to lacking mmBCFAs in worms. Tissue-specific analysis shows that restoration of BCKDH function in multiple tissues can rescue the defects, but is especially effective in neurons. Taken together, we conclude that mmBCFA deficiency is largely responsible for the developmental defects in the worm and conceivably might also be a critical contributor to the pathology of human MSUD.

  17. Glatiramer Acetate, Dimethyl Fumarate, and Monomethyl Fumarate Upregulate the Expression of CCR10 on the Surface of Natural Killer Cells and Enhance Their Chemotaxis and Cytotoxicity

    Science.gov (United States)

    Maghazachi, Azzam A.; Sand, Kristin L.; Al-Jaderi, Zaidoon

    2016-01-01

    In vitro harnessing of immune cells is the most important advance in the field of cancer immunotherapy. Results shown in the current paper may be used to harness natural killer (NK) cells in vitro. It is observed that drugs used to treat multiple sclerosis such as glatiramer acetate, dimethyl fumarate, and monomethyl fumarate upregulate the expression of chemokines receptor 10 (CCR10) on the surface of human IL-2-activated NK cells. This is corroborated with increased chemotaxis of these cells toward the concentration gradients of the ligands for CCR10, namely CCL27 and CCL28. It is also demonstrated that these three drugs enhance NK cell cytotoxicity against tumor target cells, an activity that is abrogated by prior incubation of the cells with anti-CCR10 antibody. Because CCL27 and CCL28 are secreted by selective tumor types such as malignant melanoma, squamous cell carcinomas, and colorectal cancer, respectively, it is hypothesized that activated NK cells may be harnessed in vitro with any of these drugs before utilizing them as a therapeutic modality for cancer.

  18. Lithiated and sulphonated poly(ether ether ketone) solid state electrolyte films for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, K.-F.; Su, S.-H., E-mail: minimono42@gmail.com

    2013-10-01

    Poly(ether ether ketone) (PEEK) films have been synthesised and used as solid-state electrolytes for supercapacitors. In order to increase their ion conductivity, the PEEK films were sulphonated by sulphuric acid, and various amounts of LiClO{sub 4} were added. The solid-state electrolyte films were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The ionic conductivities of the electrolyte films were analysed by performing electrochemical impedance spectroscopy. The obtained electrolyte films can be sandwiched or directly coated on activated carbon electrodes to form solid-state supercapacitors. The electrochemical characteristics of these supercapacitors were investigated by performing cyclic voltammetry and charge–discharge tests. Under an optimal content of LiClO{sub 4}, the supercapacitor can provide a capacitance as high as 190 F/g. After 1000 cycles, the supercapacitors show almost no capacitance fading, indicating high stability of the solid-state electrolyte films. - Highlights: • Poly(ether ether ketone) (PEEK) films have been used as solid-state electrolytes. • LiClO4 addition can efficiently improve the ionic conductivity. • Supercapacitors using PEEK electrolyte films deliver high capacitance.

  19. Syntheses and GABA uptake properties of 6-ether- and 6-enol ether-substituted nipecotic acids.

    Science.gov (United States)

    N'Goka, Victor; Bissantz, Caterina; Bisel, Philippe; Stenbøl, Tine B; Krogsgaard-Larsen, Povl; Schlewer, Gilbert

    2004-07-01

    6-aralkylether- and 6-arylenol-ether-substituted nipecotic acids were synthesized. These analogues are poor GABA uptake inhibitors. The electronegative region concept developed in the N-substituted nipecotic acid series cannot be transferred on the side chain of this series of 6-substituted analogues.

  20. Novel high T{sub g} high-strength poly(aryl ether)s

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Maier, G. [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl fuer Makromolekulare Stoffe

    1999-08-01

    A novel 2-perfluoroalkyl-activated bisfluoro monomer has been synthesized successfully using a Pd(0)-catalyzed cross-coupling reaction of 4-fluoro-3-trifluoromethyl phenyl boronic acid with 4,4{prime}-dibromodiphenylbenzene. This monomer was converted to novel poly(aryl ether)s by nucleophilic displacement of the fluorine atoms on the benzene ring with several bisphenols. The products obtained by displacement of the fluorine atoms exhibit weight average molar masses up to 1.06 {times} 10{sup 5} g/mol in GPC. These poly(aryl ether)s showed outstanding thermooxidative stability up to 534 C for 5% weight loss in TGA under synthetic air and high glass transition temperatures (T{sub g}) even up to 300 C in DSC and DMTA. These polymers are soluble in a wide range of organic solvents, e.g., CHCl{sub 3}, THF, NMP, DMF, toluene, etc., and are insoluble in DMSO and acetone. Transparent thin films of these polymers cast from DMF exhibited tensile strengths up to 115 MPa, moduli up to 2.59 GPa, and elongations up to 120% depending on their exact repeating unit structures. These values are comparable to those of high performance thermoplastic materials such as PEEK or Ultem PEI.

  1. Novel high T[sub g] high-strength poly(aryl ether)s

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Maier, G. (Technische Univ. Muenchen, Garching (Germany). Lehrstuhl fuer Makromolekulare Stoffe)

    1999-08-01

    A novel 2-perfluoroalkyl-activated bisfluoro monomer has been synthesized successfully using a Pd(0)-catalyzed cross-coupling reaction of 4-fluoro-3-trifluoromethyl phenyl boronic acid with 4,4[prime]-dibromodiphenylbenzene. This monomer was converted to novel poly(aryl ether)s by nucleophilic displacement of the fluorine atoms on the benzene ring with several bisphenols. The products obtained by displacement of the fluorine atoms exhibit weight average molar masses up to 1.06 [times] 10[sup 5] g/mol in GPC. These poly(aryl ether)s showed outstanding thermooxidative stability up to 534 C for 5% weight loss in TGA under synthetic air and high glass transition temperatures (T[sub g]) even up to 300 C in DSC and DMTA. These polymers are soluble in a wide range of organic solvents, e.g., CHCl[sub 3], THF, NMP, DMF, toluene, etc., and are insoluble in DMSO and acetone. Transparent thin films of these polymers cast from DMF exhibited tensile strengths up to 115 MPa, moduli up to 2.59 GPa, and elongations up to 120% depending on their exact repeating unit structures. These values are comparable to those of high performance thermoplastic materials such as PEEK or Ultem PEI.

  2. Alternariol 9-O-methyl ether

    Directory of Open Access Journals (Sweden)

    Brett A. Neilan

    2012-05-01

    Full Text Available The title compound (AME; systematic name: 3,7-dihydroxy-9-methoxy-1-methyl-6H-benzo[c]chromen-6-one, C15H12O5, was isolated from an endophytic fungi Alternaria sp., from Catharanthus roseus (common name: Madagascar periwinkle. There is an intramolecular O—H...O hydrogen bond in the essentially planar molecule (r.m.s. deviation 0.02 Å. In the crystal, the molecule forms an O—H...O hydrogen bond with its centrosymmetric counterpart with four bridging interactions (two O—H...O and two C—H...O. The almost planar sheets of the dimeric units thus formed are stacked along b axis via C—H...π and π–π contacts [with C...C short contacts between aromatic moieties of 3.324 (3, 3.296 (3 and 3.374 (3 Å].

  3. 75 FR 28804 - An Exposure Assessment of Polybrominated Diphenyl Ethers (PBDEs)

    Science.gov (United States)

    2010-05-24

    ... AGENCY An Exposure Assessment of Polybrominated Diphenyl Ethers (PBDEs) AGENCY: Environmental Protection...'s 2006 Polybrominated Diphenyl Ethers (PBDEs) Project Plan. This document ] provides an assessment of the exposure of Americans to polybrominated diphenyl ethers (PBDEs), a class of brominated...

  4. Endothelial function and vascular oxidative stress in long-lived GH/IGF-deficient Ames dwarf mice

    Science.gov (United States)

    Csiszar, Anna; Labinskyy, Nazar; Perez, Viviana; Recchia, Fabio A.; Podlutsky, Andrej; Mukhopadhyay, Partha; Losonczy, Gyorgy; Pacher, Pal; Austad, Steven N.; Bartke, Andrzej; Ungvari, Zoltan

    2008-01-01

    Hypopituitary Ames dwarf mice have low circulating growth hormone (GH)/IGF-I levels, and they have extended longevity and exhibit many symptoms of delayed aging. To elucidate the vascular consequences of Ames dwarfism we compared endothelial O2•− and H2O2 production, mitochondrial reactive oxygen species (ROS) generation, expression of antioxidant enzymes, and nitric oxide (NO) production in aortas of Ames dwarf and wild-type control mice. In Ames dwarf aortas endothelial O2•− and H2O2 production and ROS generation by mitochondria were enhanced compared with those in vessels of wild-type mice. In Ames dwarf aortas there was a less abundant expression of Mn-SOD, Cu,Zn-SOD, glutathione peroxidase (GPx)-1, and endothelial nitric oxide synthase (eNOS). NO production and acetylcholine-induced relaxation were also decreased in aortas of Ames dwarf mice. In cultured wild-type mouse aortas and in human coronary arterial endothelial cells treatment with GH and IGF significantly reduced cellular O2•− and H2O2 production and ROS generation by mitochondria and upregulated expression of Mn-SOD, Cu,Zn-SOD, GPx-1, and eNOS. Thus GH and IGF-I promote antioxidant phenotypic changes in the endothelial cells, whereas Ames dwarfism leads to vascular oxidative stress. PMID:18757483

  5. A non-randomized [corrected] controlled trial of the active music engagement (AME) intervention on children with cancer.

    Science.gov (United States)

    Robb, Sheri L; Clair, Alicia A; Watanabe, Masayo; Monahan, Patrick O; Azzouz, Faouzi; Stouffer, Janice W; Ebberts, Allison; Darsie, Emily; Whitmer, Courtney; Walker, Joey; Nelson, Kirsten; Hanson-Abromeit, Deanna; Lane, Deforia; Hannan, Ann

    2008-07-01

    Coping theorists argue that environmental factors affect how children perceive and respond to stressful events such as cancer. However, few studies have investigated how particular interventions can change coping behaviors. The active music engagement (AME) intervention was designed to counter stressful qualities of the in-patient hospital environment by introducing three forms of environmental support. The purpose of this multi-site randomized controlled trial was to determine the efficacy of the AME intervention on three coping-related behaviors (i.e. positive facial affect, active engagement, and initiation). Eighty-three participants, ages 4-7, were randomly assigned to one of three conditions: AME (n = 27), music listening (ML; n = 28), or audio storybooks (ASB; n = 28). Conditions were videotaped to facilitate behavioral data collection using time-sampling procedures. After adjusting for baseline differences, repeated measure analyses indicated that AME participants had a significantly higher frequency of coping-related behaviors compared with ML or ASB. Positive facial affect and active engagement were significantly higher during AME compared with ML and ASB (p<0.0001). Initiation was significantly higher during AME than ASB (p<0.05). This study supports the use of the AME intervention to encourage coping-related behaviors in hospitalized children aged 4-7 receiving cancer treatment. (c) 2007 John Wiley & Sons, Ltd.

  6. Use of the modified Ames test as an indicator of the carcinogenicity of residual aromatic extracts

    Energy Technology Data Exchange (ETDEWEB)

    Boogaard, P.; Hedelin, A.; Riley, A.; Rushton, E.; Vaissiere, M.; Minsavage, G.; Rohde, A.; Dalbey, W.

    2013-01-15

    Existing data demonstrate that residual aromatic extracts (RAEs) can be either carcinogenic or non-carcinogenic. CONCAWE had previously concluded that 'Although limited data available indicate that some RAEs are weakly carcinogenic, it is not possible to provide a general recommendation. Classify on a case-by-case basis' (CONCAWE 2005). Therefore CONCAWE's Health/Toxicology Subgroup (H/TSG) has developed a proposal for the use of the modified Ames test as a short-term predictive screening tool for decisions on the classification of RAEs for carcinogenicity. The relationship between RAE chemistry and carcinogenic potential is not as well understood as it is for some other categories of substances, e.g. Other Lubricant Base Oils (OLBO). However, a correlation has been found between the results of the skin carcinogenicity bioassay and the mutagenicity index (MI) obtained from the modified Ames test. Data supporting this correlation are summarised in this report. The H/TSG confirmed that the modified Ames test can be used as a predictive screening tool and that a cut-off value can be established to make a distinction between carcinogenic and non-carcinogenic products. RAEs with a MI > 0.4 demonstrated carcinogenic potential upon dermal application to mouse skin with chronic exposure. RAEs with a MI > 0.4 did not demonstrate a carcinogenic potential. To justify the use of the modified Ames test with RAEs, additional analysis of the repeatability of the test with RAEs was required. With this objective, CONCAWE sponsored a round robin study with different samples of RAEs from member companies, at three different laboratories. The repeatability demonstrated in the round robin study with RAEs support the proposed use of the modified Ames test. As part of the tools available for use by member companies, the H/TSG proposed a standard operating procedure (SOP) (included as an Appendix to this report) on the conduct of the modified Ames test with RAEs. The H

  7. Next Generation Framework for Aquatic Modeling of the Earth System (NextFrAMES)

    Science.gov (United States)

    Fekete, B. M.; Wollheim, W. M.; Lakhankar, T.; Vorosmarty, C. J.

    2008-12-01

    Earth System model development is becoming an increasingly complex task. As scientists attempt to represent the physical and bio-geochemical processes and various feedback mechanisms in unprecedented detail, the models themselves are becoming increasingly complex. At the same time, the surrounding IT infrastructure needed to carry out these detailed model computations is growing increasingly complex as well. To be accurate and useful, Earth System models must manage a vast amount of data in heterogenous computing environments ranging from single CPU systems to Beowulf type computer clusters. Scientists developing Earth System models increasingly confront obstacles associated with IT infrastructure. Numerous development efforts are on the way to ease that burden and offer model development platforms that reduce IT challenges and allow scientists to focus on their science. While these new modeling frameworks (e.g. FMS, ESMF, CCA, OpenMI) do provide solutions to many IT challenges (performing input/output, managing space and time, establishing model coupling, etc.), they are still considerably complex and often have steep learning curves. Over the course of the last fifteen years ,the University of New Hampshire developed several modeling frameworks independently from the above-mentioned efforts (Data Assembler, Frameworks for Aquatic Modeling of the Earth System and NextFrAMES which is continued at CCNY). While the UNH modeling frameworks have numerous similarities to those developed by other teams, these frameworks, in particular the latest NextFrAMES, represent a novel model development paradigm. While other modeling frameworks focus on providing services to modelers to perform various tasks, NextFrAMES strives to hide all of those services and provide a new approach for modelers to express their scientific thoughts. From a scientific perspective, most models have two core elements: the overall model structure (defining the linkages between the simulated processes

  8. Application of simplified PC-SAFT to glycol ethers

    DEFF Research Database (Denmark)

    Avlund, Ane Søgaard; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2012-01-01

    The simplified PC-SAFT (sPC-SAFT) equation of state is applied for binary glycol ether-containing mixtures, and it is investigated how the results are influenced by inclusion of intramolecular association in the association theory. Three different glycol ethers are examined: 2-methoxyethanol, 2-e...

  9. Congenital malformations and maternal occupational exposure to glycol ethers

    NARCIS (Netherlands)

    Cordier, S; Bergeret, A; Goujard, J; Ha, MC; Ayme, S; Calzolari, E; DeWalle, HEK; KnillJones, R; Candela, S; Dale, [No Value; Dananche, B; deVigan, C; Fevotte, J; Kiel, G; Mandereau, L

    1997-01-01

    Glycol ethers are found in a wide range of domestic and industrial products, many of which are used in women's work environments. Motivated by concern about their potential reproductive toxicity, we have evaluated the risk of congenital malformations related to glycol ether exposure during preg nanc

  10. Characterization of Poly(ether)urethanes - High Resolution Thermogravimetric Analysis

    Science.gov (United States)

    2004-02-01

    ether)urethanes.11 Table 5. Percent weight loss for steps in stepwise isothermal TGA analysis .......................... 14 viii DRDC Atlantic...Stepwise isothermal plots for the six poly(ether)urethanes. Table 5. Percent weight loss for steps in stepwise isothermal TGA analysis . SAMPLE/ % WT LOSS

  11. Quantitative predictivity of the transformation in vitro assay compared with the Ames test. [Hamsters

    Energy Technology Data Exchange (ETDEWEB)

    Parodi, S.; Taningher, M.; Russo, P.; Pala, M.; Vecchio, D.; Fassina, G.; Santi, L.

    For 59 chemical compounds, homogeneous data on transformation in vitro, mutagenicity in the Ames test, and carcinogenicity was reviewed. The potency in inducing transformation in vitro in hamster fibroblast cells was compared with the carcinogenic potency and a modest correlation coefficient was found between the two parameters. For these same 59 compounds it was also possible to compare mutagenic potency in the Ames test with carcinogenic potency. The correlation level was very similar. The predictivity of transformation in vitro increased significantly when only compounds for which some kind of dose-response relationship was available were utilized. This result stresses the importance of the quantitative aspect of the response in predictivity studies. The present study is compared with previous studies on the quantitative predictivity of different short-term tests. The work is not definitive, but gives an idea of the possible type of approach to the problem of comparing quantitative predictivities.

  12. Lanthanum nitrate genotoxicity evaluation: Ames test, mouse micronucleus assay, and chromosome aberration test.

    Science.gov (United States)

    Yang, Hui; Zhang, Xiaopeng; Liu, Haibo; Cui, Wenming; Zhang, Qiannan; Li, Yongning; Yu, Zhou; Jia, Xudong

    2016-11-01

    The increasing use of rare-earth elements (REE) and their compounds has led to their accumulation in the environment and has raised concern about their safety. The toxic effects of REE such as lanthanum are largely unknown; genotoxicity studies have been limited and results are controversial. We evaluated the genotoxicity of lanthanum nitrate (La(NO3)3) in several in vitro and in vivo tests, including bacterial reverse mutation assay (Ames test), mouse bone marrow micronucleus assay, and chromosome aberration assay. La(NO3)3 was not mutagenic in the Ames test. La(NO3)3 did not increase the frequencies of bone marrow micronuclei or chromosome aberration in the mouse after repeated treatments at oral doses up to 735 (females) and 855mg/kg (males). The compound did not increase the frequency of chromosome aberrations in CHO cells in vitro. These results indicate that lanthanum is not a genotoxic hazard.

  13. The NASA Ames Life Sciences Data Archive: Biobanking for the Final Frontier

    Science.gov (United States)

    Rask, Jon; Chakravarty, Kaushik; French, Alison J.; Choi, Sungshin; Stewart, Helen J.

    2017-01-01

    The NASA Ames Institutional Scientific Collection involves the Ames Life Sciences Data Archive (ALSDA) and a biospecimen repository, which are responsible for archiving information and non-human biospecimens collected from spaceflight and matching ground control experiments. The ALSDA also manages a biospecimen sharing program, performs curation and long-term storage operations, and facilitates distribution of biospecimens for research purposes via a public website (https:lsda.jsc.nasa.gov). As part of our best practices, a tissue viability testing plan has been developed for the repository, which will assess the quality of samples subjected to long-term storage. We expect that the test results will confirm usability of the samples, enable broader science community interest, and verify operational efficiency of the archives. This work will also support NASA open science initiatives and guides development of NASA directives and policy for curation of biological collections.

  14. Robust Mosaicking of Stereo Digital Elevation Models from the Ames Stereo Pipeline

    Science.gov (United States)

    Kim, Tae Min; Moratto, Zachary M.; Nefian, Ara Victor

    2010-01-01

    Robust estimation method is proposed to combine multiple observations and create consistent, accurate, dense Digital Elevation Models (DEMs) from lunar orbital imagery. The NASA Ames Intelligent Robotics Group (IRG) aims to produce higher-quality terrain reconstructions of the Moon from Apollo Metric Camera (AMC) data than is currently possible. In particular, IRG makes use of a stereo vision process, the Ames Stereo Pipeline (ASP), to automatically generate DEMs from consecutive AMC image pairs. However, the DEMs currently produced by the ASP often contain errors and inconsistencies due to image noise, shadows, etc. The proposed method addresses this problem by making use of multiple observations and by considering their goodness of fit to improve both the accuracy and robustness of the estimate. The stepwise regression method is applied to estimate the relaxed weight of each observation.

  15. Early Postnatal Administration of Growth Hormone Increases Tuberoinfundibular Dopaminergic Neuron Numbers in Ames Dwarf Mice

    OpenAIRE

    Khodr, Christina E; Clark, Sara; Bokov, Alex F.; Richardson, Arlan; Strong, Randy; Hurley, David L.; Phelps, Carol J.

    2010-01-01

    Hypothalamic tuberoinfundibular dopaminergic (TIDA) neurons secrete dopamine, which inhibits pituitary prolactin (PRL) secretion. PRL has demonstrated neurotrophic effects on TIDA neuron development in PRL-, GH-, and TSH-deficient Ames (df/df) and Snell (dw/dw) dwarf mice. However, both PRL and PRL receptor knockout mice exhibit normal-sized TIDA neuron numbers, implying GH and/or TSH influence TIDA neuron development. The current study investigated the effect of porcine (p) GH on TIDA neuron...

  16. Microplate Ames MPF™ test use in assessment of mutagenic properties of dust pollution

    Directory of Open Access Journals (Sweden)

    Agnieszka Kozłowska

    2012-09-01

    Full Text Available Background: Highly industrialized Upper Silesia Region is particularly polluted by both anthropogenic and natural airborne particulate matters, which may lead to negative health effects in human. Materials and methods: The aim of the study was to assess the mutagenic properties of dust extracts which were collected in six cities in the Silesian Voivodeship. Dust samples were collected on glass fiber filters by the aspirator with air flow ca. 1 m3/min. Extraction of pollution was carried out using dichlorometane. The extracted samples were dissolved in dimethylsulfoxide (DMSO. The mutagenic properties were assessed using microplate Ames assay MPFTM with the use of bacteria Salmonella typhimurium strain TA98 and TA100. Results: In microplate Ames assay MPFTM there was observed a linear dose-response relationship in both metabolic variants of TA98 strain. Similar relationship was observed for TA100 strain with metabolic activation (S9. Mutagenic activity (AM of 100% extracts for TA98 strain in both metabolic variants (S9 exceeded 2, what indicate highly mutagenic effects of dust extracts. There was no mutagenic activity observed in the assay with TA100 (S9, AM 1. In the variant with exogenous metabolic activation (S9 in TA100 strain AM values ranged from AM1,160,15 to AM9,671,02. Mutagenic activity varied between different cities. Conclusions: The study demonstrated that microplate Ames assay MPFTM is fast and complex method of assessing the mutagenic properties of dust pollution, which exert toxic effect on organisms. The use of microplate Ames assay MPFTM together with chemical analyses of air dust pollution may evaluate the level of exposure in the environment and enable to perform health risk assessment in populations exposed to mutagenic, toxic and cytotoxic substances.

  17. Study of optical techniques for the Ames unitary wind tunnel. Part 5: Infrared imagery

    Science.gov (United States)

    Lee, George

    1992-01-01

    A survey of infrared thermography for aerodynamics was made. Particular attention was paid to boundary layer transition detection. IR thermography flow visualization of 2-D and 3-D separation was surveyed. Heat transfer measurements and surface temperature measurements were also covered. Comparisons of several commercial IR cameras were made. The use of a recently purchased IR camera in the Ames Unitary Plan Wind Tunnels was studied. Optical access for these facilities and the methods to scan typical models was investigated.

  18. Shock Tube and Ballistic Range Facilities at NASA Ames Research Center

    Science.gov (United States)

    Grinstead, Jay H.; Wilder, Michael C.; Reda, Daniel C.; Cornelison, Charles J.; Cruden, Brett A.; Bogdanoff, David W.

    2010-01-01

    The Electric Arc Shock Tube (EAST) facility and the Hypervelocity Free Flight Aerodynamic Facility (HFFAF) at NASA Ames Research Center are described. These facilities have been in operation since the 1960s and have supported many NASA missions and technology development initiatives. The facilities have world-unique capabilities that enable experimental studies of real-gas aerothermal, gas dynamic, and kinetic phenomena of atmospheric entry.

  19. Development of the AMES network throughout the 4th and 5th EURATOM framework programmes

    Energy Technology Data Exchange (ETDEWEB)

    Sevini, F.; Debarberis, L.; Toerroenen, K.; Gerard, R.; Davies, L.M

    2004-08-01

    The AMES (Ageing Materials European Strategy) network started its activity in 1993 with the aim of studying ageing mechanisms and remedial procedures for structural materials used for nuclear reactor components. Acad. L.M. Davies led AMES during successful development from the beginning until the end of the 4th Framework Programme, and greatly contributed during the 5th Framework Programme with his precious advice and as EPLAF Chairman. Among others, during the 4th EURATOM Framework Program some projects co-financed by the European Commission were carried out on non-destructive monitoring techniques for thermal ageing, reference dosimetry, and reconstitution techniques applied to Charpy specimens. Within the 5th EURATOM Framework Program, other projects were approved for funding and are currently running. Their focus is on the mechanism of irradiation embrittlement of reactor pressure vessel materials, namely the influence of chemical composition, on the improvement of surveillance temperature measurement, on the validation of the master curve approach, and on non-destructive techniques to monitor ageing of irradiated steels, which all have relations to plant life management and extension. The paper will present an overview of the outcome of the projects having plant life management implications, especially non-destructive techniques applied to thermal ageing and neutron embrittlement monitoring (AMES-NDT and GRETE), improved surveillance for VVER 440 reactors (COBRA), dosimetry (AMES-DOSIMETRY, MADAM and REDOS), PISA and FRAME. The project co-ordinators have provided most of the material here presented, but together with them all the project members gave their contribution and are therefore acknowledged.

  20. Study of optical techniques for the Ames unitary wind tunnel: Digital image processing, part 6

    Science.gov (United States)

    Lee, George

    1993-01-01

    A survey of digital image processing techniques and processing systems for aerodynamic images has been conducted. These images covered many types of flows and were generated by many types of flow diagnostics. These include laser vapor screens, infrared cameras, laser holographic interferometry, Schlieren, and luminescent paints. Some general digital image processing systems, imaging networks, optical sensors, and image computing chips were briefly reviewed. Possible digital imaging network systems for the Ames Unitary Wind Tunnel were explored.

  1. Comparative investigations of genotoxic activity of five nitriles in the comet assay and the Ames test.

    Science.gov (United States)

    Wu, Jong-C; Hseu, You C; Chen, Chin-H; Wang, Shu-H; Chen, Ssu C

    2009-09-30

    Two short-term assays, the modified Ames test and the comet assay, were carried out to evaluate the genotoxicity of five nitriles (acetonitrile, propionitrile, methacrylonitrile, butyronitrile, and benzonitrile). With the comet assay, all the nitriles studied were found to induce the genotoxicity in human lymphocytes and Hep G2 cells. Except for butyronitrile, the genotoxic potency in lymphocytes was more pronounced than that in Hep G2 cells, and the rank order of genotoxicity induced by these five nitriles in lymphocytes was different from that in Hep G2 cells, indicating that the pathways leading to genotoxicity in both types of cells were different. In the modified Ames test, no tested nitriles showed mutagenic activity on Salmonella typhimurium strain TA 98 and TA 100 with and without metabolic activation. Comparing the results obtained from both tests in this study, the comet assay seems to be more sensitive than the modified Ames test. Thus, the comet assay can be used to detect the genotoxicity of all nitriles.

  2. Ameli-EAUR project: which lessons for the promotion of agricultural value chains?

    Science.gov (United States)

    Traoré, M. B.; Dakouré, M. S.; Maïga, A. H.

    2017-03-01

    Due to the lack of rain, dry spell and agricultural insufficient inputs, agricultural yields are very low and do not allow achieving food self-sufficiency in countries such as Burkina Faso. To fight against this situation in the context of climate change, several researches have emerged such as agronomic research with the promotion of crop varieties that require little water and short growth period. The Ameli-EAUR project is another example of research. This project aimed to promote hygiene and sanitation by the use of sanitation by-product in rural and sub-urban areas of Burkina Faso. Ameli-EAUR project was initiated and implemented within five years. Completed in 2015, it appears necessary to think over its impacts on production hence the question: which lessons for the promotion of agriculture, specifically for agricultural value chains“? Based on the result of a post-survey performed one year after the end of the project, the aim of this presentation is to show that project can support the promotion of agricultural Value Chains in spite of difficulties if we take into account some parameters. To do this, we will start by presenting briefly Ameli-EAUR; then we will take stock of the project; finally, we will examine the possibilities it offers for the promotion of agricultural value chains, taking as example the vegetable gardening. We will also try to show the limits of value chains which are presented nowadays as a solution to many problems of agriculture in Africa.

  3. A mutagenicity and cytotoxicity study of limonium effusum aqueous extracts by Allium, Ames and MTT tests.

    Science.gov (United States)

    Eren, Y; Ozata, A; Konuk, M; Akyil, D; Liman, R

    2015-01-01

    Nowadays plants or plant extracts have become very important for alternative medicine. Plants and their extracts have many therapeutical advantages but some of them are potentially toxic, mutagenic, carcinogenic and teratogenic. Root, stem and leafparts of Limonium effusum were used in this study and this species is an endemic species for Turkey. Mutagenic and cytotoxic effects of root, stem and leaf aqueous extracts were observed with Allium, Ames and MTT tests. Allium root growth inhibition test and mitotic index studies showed that aqueous extracts have dose-dependent toxic effects. Chromosome aberration studies indicated that especially sticky chromosome, anaphase-telophase disorder and laggard chromosome anomalies were highly observed. Ames test performed with Limonium effusum root aqueous extracts, showed weak mutagenic effects in Salmonella typhimurium TA98 strain with S9. MTT test based on mitochondrial activity indicated that most of the aqueous extracts have cytotoxic effects. This study aimed to determine the possible mutagenic and cytotoxic effects of L. effusum aqueous extracts by using bacterial, plant and mammalian cells. This research showed that some low concentrations of the L. effusum extracts have inhibited cytotoxic effects but high concentrations have induced cytotoxicity. On the other hand only a weak mutagenic activity was identified by Ames test with TA98 S9(+).

  4. Consolidated Laser-Induced Fluorescence Diagnostic Systems for the NASA Ames Arc Jet Facilities

    Science.gov (United States)

    Grinstead, Jay; Wilder, Michael C.; Porter, Barry; Brown, Jeff; Yeung, Dickson; Battazzo, Steve; Brubaker, Tim

    2016-01-01

    The spectroscopic diagnostic technique of two photon absorption laser-induced fluorescence (TALIF) of atomic species for non-intrusive arc jet flow property measurement was first implemented at NASA Ames in the mid-1990s. Use of TALIF expanded at NASA Ames and to NASA Johnsons arc jet facility in the late 2000s. In 2013-2014, NASA combined the agency's large-scale arc jet test capabilities at NASA Ames. Concurrent with that effort, the agency also sponsored a project to establish two comprehensive LIF diagnostic systems for the Aerodynamic Heating Facility (AHF) and Interaction Heating Facility (IHF) arc jets. The scope of the project enabled further engineering development of the existing IHF LIF system as well as the complete reconstruction of the original AHF LIF system. The updated LIF systems are identical in design and capability. They represent the culmination of over 20 years of development experience in transitioning a specialized laboratory research tool into a measurement system for large-scale, high-demand test facilities. This paper documents the overall system design from measurement requirements to implementation. Representative data from the redeveloped AHF and IHF LIF systems are also presented.

  5. NASA Ames DEVELOP Interns: Helping the Western United States Manage Natural Resources One Project at a Time

    Science.gov (United States)

    Justice, Erin; Newcomer, Michelle

    2010-01-01

    The western half of the United States is made up of a number of diverse ecosystems ranging from arid desert to coastal wetlands and rugged forests. Every summer for the past 7 years students ranging from high school to graduate level gather at NASA Ames Research Center (ARC) as part of the DEVELOP Internship Program. Under the guidance of Jay Skiles [Ames Research Center (ARC) - Ames DEVELOP Manager] and Cindy Schmidt [ARC/San Jose State University Ames DEVELOP Coordinator] they work as a team on projects exploring topics including: invasive species, carbon flux, wetland restoration, air quality monitoring, storm visualizations, and forest fires. The study areas for these projects have been in Washington, Utah, Oregon, Nevada, Hawaii, Alaska and California. Interns combine data from NASA and partner satellites with models and in situ measurements to complete prototype projects demonstrating how NASA data and resources can help communities tackle their Earth Science related problems.

  6. State of the Art High-Throughput Approaches to Genotoxicity: Flow Micronucleus, Ames II, GreenScreen and Comet

    Science.gov (United States)

    State of the Art High-Throughput Approaches to Genotoxicity: Flow Micronucleus, Ames II, GreenScreen and Comet (Presented by Dr. Marilyn J. Aardema, Chief Scientific Advisor, Toxicology, Dr. Leon Stankowski, et. al. (6/28/2012)

  7. Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins,

    Directory of Open Access Journals (Sweden)

    Mathew Obichukwu EDOGA

    2006-07-01

    Full Text Available First, phenol - formaldehyde (PF and urea - formaldehyde (UFII resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure. Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER (i.e. UFIII and glycerol (GLYC (i.e. UFV cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out.The results showed that the unmodified UF resin (UF II synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, showed features in their spectra which are consistent with a tri-, and/or tetra-substituted urea in the reaction to give a 3 - dimensional network cured UF resin. Modification of the UF resin(UF II with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I, the only clear distinction between spectra for the UF resin II and UF resins (III/V is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V, cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.

  8. AMeDASデータを用いた時刻別日射量の推定法

    OpenAIRE

    赤坂, 裕; "二宮, 秀與"; アカサカ, ヒロシ; ニミヤ, ヒデヨ; Akasaka, Hiroshi; NIMIYA, Hideyo

    1986-01-01

    This paper reports on a method to estimate the hourly solar radiation using AMeDAS (Automated Meteorological Data Aquisition System) data. AMeDAS is a weather data measuring system established by the Meteorological Agency of Japan and can provide us with accurate, comprehensive data because it covers all of the Japanese islands with 840 measuring stations. Sunshine hours over a long period is known to be strongly correlated with the global solar radiation of the corresponding period. In chapt...

  9. Polymeric 32-channel arrayed waveguide grating multiplexer using fluorinated poly (ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    Fei Wang(王菲); Wei Sun(孙伟); Aize Li(李艾泽); Maobin Yi(衣茂斌); Zhenhua Jiang(姜振华); Daming Zhang(张大明)

    2004-01-01

    In wavelength division multiplexing (WDM) systems, an arrayed waveguide grating (AWG) multiplexer is a key component. A polymeric AWG multiplexer has recently attracted much attention due to its low cost processing and a potential of integration with other devices. Fluorinated poly (ether ether ketone)(FPEEK) is excellent material for fabrication of optical waveguides due to its low absorption loss at 1.55-μm wavelength and high thermal stability. A 32-channel AWG multiplexer has been designed based on the grating diffraction theory and fabricated using newly synthesized FPEEK. During the fabrication process of the Polymer/Si AWG device, spin coating, vaporizing, photolithographic patterning and reactive ion etching (RIE) are used. The AWG multiplexer measurement system is based on a tunable semiconductor laser, infrared camera and a Peltier-type heater. The device exhibits a wavelength channel spacing of 0.8nm and a center wavelength of 1548 nm in the room temperature.

  10. Origin of mechanical modifications in poly (ether ether ketone)/carbon nanotube composite

    Energy Technology Data Exchange (ETDEWEB)

    Pavlenko, Ekaterina; Puech, Pascal; Bacsa, Wolfgang, E-mail: wolfgang.bacsa@cemes.fr [CEMES-CNRS and University of Toulouse, 29 Jeanne Marvig, 31055 Toulouse (France); Boyer, François; Olivier, Philippe [Université de Toulouse, Institut Clément Ader, I.U.T. Université Paul Sabatier - 133C Avenue de Rangueil - B.P. 67701, 31077 Toulouse CEDEX 4 (France); Sapelkin, Andrei [School of Physics and Astronomy, Queen Mary, University of London, Mile End Road, E1 4NS London (United Kingdom); King, Stephen; Heenan, Richard [ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX Didcot (United Kingdom); Pons, François; Gauthier, Bénédicte; Cadaux, Pierre-Henri [AIRBUS FRANCE (B.E. M and P Toulouse), 316 Route de Bayonne, 31060 Toulouse (France)

    2014-06-21

    Variations in the hardness of a poly (ether ether ketone) beam electrically modified with multi-walled carbon nanotubes (MWCNT, 0.5%-3%) are investigated. It is shown that both rupture and hardness variations correlate with the changes in carbon nanotube concentration when using micro indentation and extended Raman imaging. Statistical analysis of the relative spectral intensities in the Raman image is used to estimate local tube concentration and polymer crystallinity. We show that the histogram of the Raman D band across the image provides information about the amount of MWCNTs and the dispersion of MWCNTs in the composite. We speculate that we have observed a local modification of the ordering between pure and modified polymer. This is partially supported by small angle neutron scattering measurements, which indicate that the agglomeration state of the MWCNTs is the same at the concentrations studied.

  11. Sulfonated poly(tetramethydiphenyl ether ether ketone) membranes for vanadium redox flow battery application

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Zhensheng; Bi, Cheng; Dai, Hua [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Huamin; Li, Xianfeng [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China)

    2011-01-01

    Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium redox flow battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge-discharge test. (author)

  12. Modification of Poly(ether ether ketone Polymer for Fuel Cell Application

    Directory of Open Access Journals (Sweden)

    Devesh Shukla

    2013-01-01

    Full Text Available Polyelectrolyte membrane (PEM is an important part of PEM fuel cell. Nafion is a commercially known membrane which gives the satisfactory result in PEM fuel cell operating at low temperature. Present research paper includes functionalization of Poly(ether ether ketone (PEEK polymer with phosphonic acid group. The functionalization was done with the help of nickel-based catalyst. Further, the polymer was characterized by the FTIR, EDAX, DSC, TGA, and 1H NMR, and it was found that PEEK polymer was functionalized with phosphonic acid group with good thermal stability in comparison to virgin PEEK. Finally, the thin films of functionalized polymer were prepared by solution casting method, and proton conductivity of film samples was measured by impedance spectra whose value was found satisfactory with good thermal stability in comparison to commercially available Nafion membrane.

  13. Evaluation of Stabilization Performances of Antioxidants in Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zheng; ZHOU Fu-gui; ZHANG Shu-ling; MU Jian-xin; YUE Xi-gui; WANG Gui-bin

    2012-01-01

    Two types of antioxidants(a primary antioxidant and a secondary antioxidant) were used to improve the stability of poly(ether ether ketone)(PEEK).The effects of the antioxidants on the properties of PEEK and the stabilization mechanism were investigated by some characterization methods,such as rheometer,thermogravinetric analysis(TGA),universal tester and electron spin resonance(ESR).The results indicate that the efficiency of the phosphorous antioxidant(DS) in improving the stability of PEEK was better than that of the phenolic antioxidant(DN) in both melting stability and thermal stability,and the thermal stability of PEEK sample containing 0.07%(mass fraction) DS was the best among all the samples due to the decrease of the free radicals density,as proven by ESR measurement.Additionally,no obvious changes could be observed in mechanical properties of PEEK containing antioxidants compared to those of virgin PEEK.

  14. Sulfonated poly(tetramethydiphenyl ether ether ketone) membranes for vanadium redox flow battery application

    Science.gov (United States)

    Mai, Zhensheng; Zhang, Huamin; Li, Xianfeng; Bi, Cheng; Dai, Hua

    Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium redox flow battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge-discharge test.

  15. ELECTROCHEMICAL POLYMERIZATION OF 5-CYANOINDOLE IN MIXED ELECTROLYTES OF BORON TRIFLUORIDE DIETHYL ETHERATE AND DIETHYL ETHER

    Institute of Scientific and Technical Information of China (English)

    Jing-kun Xu; Wei-qiang Zhou; Jian Hou; Shou-zhi Pu; Jing-wu Wang; Liu-shui Yan

    2006-01-01

    High quality poly(5-cyanoindole) (P5CI) films were electrosynthesized by direct anodic oxidation of 5-cyanoindole on stainless steel sheet in the mixed electrolytes of boron trifluoride diethyl etherate (BFEE) and diethyl ether (EE) (by volume 1:1) + 0.05 mol L-1 Bu4NBF4. The film formed can be peeled off the electrode into freestanding films. The addition of EE into BFEE can improve the solubility of monomer. P5CI films obtained from this medium showed excellent electrochemical behavior with conductivity of 10-2 Scm-1. Structural studies showed that the polymerization of 5-cyanoindole occurred at the 2,3 position. As-formed P5CI films were thoroughly soluble in strong polar organic solvent dimethyl sulfoxide (DMSO) while partly soluble in tetrahydrofuran (THF) or acetone. Fluorescence spectral studies indicated that P5CI was a good blue-light emitter.

  16. Dielectric properties of poly (1,4-phenylene ether-ether-sulfone)

    CERN Document Server

    Spasevska, H

    2002-01-01

    Dielectric properties of Poly (1,4-phenylene ether-ether-sulfone) are obtained from dielectric spectroscopy of the polymer pellet. The values of relative dielectric constant epsilon', dielectric losses epsilon sup , dielectric dissipation factor tan delta and complex impedance are obtained at temperature of 75 sup o C. The temperature dependence of these parameters is investigated for three frequencies (8x10 sup 4 Hz; 8x10 sup 5 Hz; 8x10 sup 6 Hz) of applied electric field. The specific conductivity sigma, which depends on temperature, is related to the ohmic resistance R, at temperature in the interval from 66 to 83 sup o C. Fitting the experimental data, the value of the activation energy U is obtained. (Original)

  17. Poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Mi-Lim; Choi, Jisun; Woo, Hyun-Su; Kumar, Vinod; Sohn, Joon-Yong; Shin, Junhwa, E-mail: shinj@kaeri.re.kr

    2014-02-15

    Highlights: • PEEK-g-PVBSA, a polymer electrolyte membrane was prepared by a radiation grafting technique. • Poly(ether ether ketone) (PEEK), an aromatic hydrocarbon polymer was used as a grafting backbone film. • The water uptake, proton conductivity, and methanol permeability of the membranes were evaluated. • PEEK-g-PVBSA membranes show considerably lower methanol permeability compared to a Nafion membrane. -- Abstract: In this study, an aromatic hydrocarbon based polymer electrolyte membrane, poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) (PEEK-g-PVBSA), has been prepared by the simultaneous irradiation grafting of vinylbenzyl chloride (VBC) monomer onto a PEEK film and subsequent sulfonation. Each chemical conversion was monitored by FT-IR and SEM–EDX instruments. The physicochemical properties including IEC, water uptake, proton conductivity, and methanol permeability of the prepared membranes were also investigated and found that the values of these properties increase with the increase of degree of grafting. It was observed that the IEC values of the prepared PEEK-g-PVBSA membranes with 32%, 58%, and 80% DOG values were 0.50, 1.05, and 1.22 meq/g while the water uptakes were 14%, 20%, and 21%, respectively. The proton conductivities (0.0272–0.0721 S/cm at 70 °C) were found to be somewhat lower than Nafion 212 (0.126 S/cm at 70 °C) at a relative humidity of 90%. However, the prepared membranes showed a considerably lower methanol permeability (0.61–1.92 × 10{sup −7} cm{sup 2}/s) compared to a Nafion 212 membrane (5.37 × 10{sup −7} cm{sup 2}/s)

  18. Mass transport of direct methanol fuel cell species in sulfonated poly(ether ether ketone) membranes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, V.S.; Boaventura, M.; Mendes, A.M.; Madeira, L.M. [LEPAE, Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Ruffmann, B.; Vetter, S.; Nunes, S.P. [GKSS Research Centre, Max-Planck Str., 21502 Geesthacht (Germany)

    2006-05-05

    Homogeneous membranes based on sulfonated poly(ether ether ketone) (sPEEK) with different sulfonation degrees (SD) were prepared and characterized. In order to perform a critical analysis of the SD effect on the polymer barrier and mass transport properties towards direct methanol fuel cell species, proton conductivity, water/methanol pervaporation and nitrogen/oxygen/carbon dioxide pressure rise method experiments are proposed. This procedure allows the evaluation of the individual permeability coefficients in hydrated sPEEK membranes with different sulfonation degrees. Nafion{sup (R)} 112 was used as reference material. DMFC tests were also performed at 50{sup o}C. It was observed that the proton conductivity and the permeability towards water, methanol, oxygen and carbon dioxide increase with the sPEEK sulfonation degree. In contrast, the SD seems to not affect the nitrogen permeability coefficient. In terms of selectivity, it was observed that the carbon dioxide/oxygen selectivity increases with the sPEEK SD. In contrast, the nitrogen/oxygen selectivity decreases. In terms of barrier properties for preventing the DMFC reactants loss, the polymer electrolyte membrane based on the sulfonated poly(ether ether ketone) with SD lower or equal to 71%, although having slightly lower proton conductivity, presented much better characteristics for fuel cell applications compared with the well known Nafion{sup (R)} 112. In terms of the DMFC tests of the studied membranes at low temperature, the sPEEK membrane with SD=71% showed to have similar performance, or even better, as that of Nafion{sup (R)} 112. However, the highest DMFC overall efficiency was achieved using sPEEK membrane with SD=52%. (author)

  19. Microwave Spectrum of the Ethylmethyl Ether Molecule

    Directory of Open Access Journals (Sweden)

    Kojiro Takagi

    2003-01-01

    Full Text Available We have observed rotational transitions of ethylmethyl ether (CH3CH2OCH3 in the 24-110 GHz frequency range. We newly assigned the transitions of four Q-branch series for J=1-38 with Ka=0-5 and six R-branch series of b-type transitions for J=7-37 with Ka=0-3. All these assigned transitions were observed to be split into two or four components due to the internal rotations of the methyl groups. We analyzed the averaged frequencies of the split components on the basis of the Watson A-reduced Hamiltonian, neglecting the effect of the internal rotations. A total of 122 transitions were fitted to eight molecular parameters to a 1s standard deviation of 24 kHz. The parameters A, B, C and DJ were improved, and DJK, Dk, dJ and dK were determined for the first time.

  20. Molecular dynamics model of dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Lin, B.; Halley, W.J. [Univ. of Minnesota, Minneapolis, MN (United States)

    1995-11-02

    We report a molecular dynamics model of the monomeric liquid dimethyl ether. The united atom approach is used to treat CH{sub 3} groups as point source centers. Partial charges are derived from the experimental dipole moment. Harmonic force constants are used for intramolecular interactions, and their values are so chosen that the model`s fundamental frequencies agree with experimental results. Because we are interested in solvation properties, the model contains flexible molecules, allowing molecular distortion and internal dynamical quantities. We report radial distribution functions and the static structure factors as well as some dynamical quantities such as the dynamical structure factor, infrared absorption, and Raman scattering spectra. Calculated results agree reasonably well with experimental and other simulation results. 25 refs., 8 figs., 1 tab.

  1. Thermolysis of phenethyl phenyl ether: A model of ether linkages in low rank coal

    Energy Technology Data Exchange (ETDEWEB)

    Britt, P.F.; Buchanan, A.C. III; Malcolm, E.A.

    1994-09-01

    Currently, an area of interest and frustration for coal chemists has been the direct liquefaction of low rank coal. Although low rank coals are more reactive than bituminous coals, they are more difficult to liquefy and offer lower liquefaction yields under conditions optimized for bituminous coals. Solomon, Serio, and co-workers have shown that: in the pyrolysis and liquefaction of low rank coals, a low temperature cross-linking reaction associated with oxygen functional groups occurs before tar evolution. A variety of pretreatments (demineralization, alkylation, and ion-exchange) have been shown to reduce these retrogressive reactions and increase tar yields, but the actual chemical reactions responsible for these processes have not been defined. In order to gain insight into the thermochemical reactions leading to cross-linking in low rank coal, we have undertaken a study of the pyrolysis of oxygen containing coal model compounds. Solid state NMR studies suggest that the alkyl aryl ether linkage may be present in modest amounts in low rank coal. Therefore, in this paper, we will investigate the thermolysis of phenethyl phenyl ether (PPE) as a model of 0-aryl ether linkages found in low rank coal, lignites, and lignin, an evolutionary precursor of coal. Our results have uncovered a new reaction channel that can account for 25% of the products formed. The impact of reaction conditions, including restricted mass transport, on this new reaction pathway and the role of oxygen functional groups in cross-linking reactions will be investigated.

  2. Cationic Poly(benzyl ether)s as Self-Immolative Antimicrobial Polymers.

    Science.gov (United States)

    Ergene, Cansu; Palermo, Edmund F

    2017-10-09

    Self-immolative polymers (SIMPs) are macromolecules that spontaneously undergo depolymerization into small molecules when triggered by specific external stimuli. We report here the first examples of antimicrobial SIMPs with potent, rapid, and broad-spectrum bactericidal activity. Their antibacterial and hemolytic activities were examined as a function of cationic functionality. Polymers bearing primary ammonium cationic groups showed more potent bactericidal activity against Escherichia coli, relative to tertiary and quaternary ammonium counterparts, whereas the quaternary ammonium polymers showed the lowest hemolytic toxicity. These antibacterial polycations undergo end-to-end depolymerization when triggered by an externally applied stimulus. Specifically, poly(benzyl ether)s end-capped with a silyl ether group and bearing pendant allyl side chains were converted to polycations by photoinitiated thiol-ene radical addition using cysteamine HCl. The intact polycations are stable in solution, but they spontaneously unzip into their component monomers upon exposure to fluoride ions, with excellent sensitivity and selectivity. Upon triggered depolymerization, the antibacterial potency was largely retained but the hemolytic toxicity was substantially reduced. Thus, we reveal the first example of a self-immolative antibacterial polymer platform that will enable antibacterial materials to spontaneously unzip into biologically active small molecules upon the introduction of a specifically designed stimulus.

  3. High temperature fuel cell membranes based on poly(arylene ether)s containing benzimidazole groups

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Sik [Los Alamos National Laboratory; Kim, Yu Seung [Los Alamos National Laboratory; Lee, Kwan - Soo [Los Alamos National Laboratory; Boncella, James M [Los Alamos National Laboratory; Kuiper, David [Los Alamos National Laboratory; Guiver, Michael D [CANADA

    2009-01-01

    Development of new high-performance polymer membranes that retain their proton conductivity under low humidity conditions is one of the most critical requirements to commercialize PEMFC systems. Current sulfonated proton exchange membranes acquire proton conductivity by water that solvates ion and carries proton. Consequently, a loss of water under low RH conditions immediately results in a loss of proton conductivity. One approach to maintain proton conductivity under low RH conditions is to replace water with a less volatile proton solvent. Kreuer has pointed out the possibility to develop fully polymeric proton-conducting membranes based on nitrogen-containing heterocycles such as imidazole, benzimidazole, and pyrazole. We have attempted to blend those less volatile proton solvent with sulfonated copolymers such as polystyrene sulfonic acid, Nafion, poly(arylene ether sulfone, BPSH-xx). [Ref. DOE review meeting 2007 and 2008] However, we observed that imidazole was slowly sublimated out as temperature and humidity increases which could cause poisoning of electro-catalyst, corrosion and losing conductivity. In this presentation, we report the synthesis of novel poly(arylene ether sulfone)s containing benzimidazole groups These benzimidazole containing polymer was blended with sulfonated poly(arylene ether sulfone). In the blend system, benzimidazole group attached to the polysulfone acts as a medium through the basic nitrogen for transfer of protons between the sulfonic acid groups. Proton conductivity of the blend membranes was investigated as a function of water content at 80 C and compared the performance with water based proton conduction system.

  4. Formulating liquid ethers for microtubular SOFCs

    Science.gov (United States)

    Kendall, Kevin; Slinn, Matthew; Preece, John

    One of the key problems of applying solid oxide fuel cells (SOFCs) in transportation is that conventional fuels like kerosene and diesel do not operate directly in SOFCs without prereforming to hydrogen and carbon monoxide which can be handled by the nickel cermet anode. SOFCs can internally reform certain hydrocarbon molecules such as methanol and methane. However, other liquid fuels usable in petrol or diesel internal combustion engines (ICEs) have not easily been reformable directly on the anode. This paper describes a search for liquid fuels which can be mixed with petrol or diesel and also injected directly into an SOFC without destroying the nickel anode. When fuel molecules such as octane are injected onto the conventional nickel/yttria stabilised zirconia (Ni/YSZ) SOFC fuel electrode, the anode rapidly becomes blocked by carbon deposition and the cell power drops to near zero in minutes. This degeneration of the anode can be inhibited by injection of air or water into the anode or by some upstream reforming just before entry to the SOFC. Some smaller molecules such as methane, methanol and methanoic acid produce a slight tendency to carbon deposition but not sufficient to prevent long term operation. In this project we have investigated a large number of molecules and now found that some liquid ethers do not significantly damage the anode when directly injected. These molecules and formulations with other components have been evaluated in this study. The theory put forward in this paper is that carbon-carbon bonds in the fuel are the main reason for anode damage. By testing a number of fuels without such bonds, particularly liquid ethers such as methyl formate and dimethoxy methane, it has been shown that SOFCs can run without substantial carbon formation. The proposal is that conventional fuels can be doped with these molecules to allow hybrid operation of an ICE/SOFC device.

  5. Vapor intrusion risk of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME) and ethyl tert-butyl ether (ETBE): A modeling study.

    Science.gov (United States)

    Ma, Jie; Xiong, Desen; Li, Haiyan; Ding, Yi; Xia, Xiangcheng; Yang, Yongqi

    2017-06-15

    Vapor intrusion of synthetic fuel additives represents a critical yet still neglected problem at sites contaminated by petroleum fuel releases. This study used an advanced numerical model to investigate the vapor intrusion potential of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME), and ethyl tert-butyl ether (ETBE). Simulated indoor air concentration of these compounds can exceed USEPA indoor air screening level for MTBE (110μg/m(3)). Our results also reveal that MTBE has much higher chance to cause vapor intrusion problems than TAME and ETBE. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the vertical screening criteria for petroleum hydrocarbons may not provide sufficient protectiveness for fuel additives, and ether oxygenates in particular. In addition to adverse impacts on human health, ether oxygenate vapor intrusion may also cause aesthetic problems (i.e., odour and flavour). Overall, this study points out that ether oxygenates can cause vapor intrusion problems. We recommend that USEPA consider including the field measurement data of synthetic fuel additives in the existing PVI database and possibly revising the PVI Guidance as necessary.

  6. Characterization of Microsolvated Crown Ethers from Broadband Rotational Spectroscopy

    Science.gov (United States)

    Perez, Cristobal; Schnell, Melanie; Blanco, Susana; Lopez, Juan Carlos

    2016-06-01

    Since they were first synthetized, crown ethers have been extensively used in organometallic chemistry due to their unparalleled binding selectivity with alkali metal cations. From a structural point of view, crown ethers are heterocycles containing oxygen and/or other heteroatoms, although the most common ones are formed from ethylene oxide unit. Crown ethers are conventionally seen as being hydrophilic inside and hydrophobic outside when the structures found for the metal cation complexes are considered. However, crown ethers are extremely flexible and in isolation may present a variety of stable conformations so that their structure may be easily adapted in presence of a strong ligand as an alkali metal cation minimize the energy of the resulting complex. Water can be considered a soft ligand which interacts with crown ethers through moderate hydrogen bonds. It is thus interesting to investigate which conformers are selected by water to form complexes, the preferred interaction sites and the possible conformational changes due to the presence of one or more water molecules. Previous studies identified microsolvated crown ethers but in all cases with a chromophore group attached to the structure. Here we present a broadband rotational spectroscopy study of microsolvated crown ethers produced in a pulsed molecular jet expansion. Several 1:1 and 1:2 crown ether:water aggregates are presented for 12-crown-4, 15-crown-5 and 18-crown-6. Unambiguous identification of the structures has been achieved using isotopic substitution within the water unit. The subtle changes induced in the structures of the crown ether monomer upon complexation and the hydrogen-bonding network that hold them together will be also discussed. F. Gámez, B. Martínez-Haya, S. Blanco,J. C. López and J. L. Alonso, Phys. Chem. Chem. Phys. 2014, 14 12912-12918 V. A. Shubert, C.W. Müller and T. Zwier, J. Phys. Chem. A 2009, 113 8067-8079

  7. 德国赫优讯EtherCAT新产品

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    EtherCAT作为实时以太网协议之一,以其强大的性能和“On the fly”的速度,以及网络抖动小于1μs的同步功能.成为发展最快的实时网络协议。同时,EtherCAT全球组织在中国代表处的设立,表明了EtherCAT全球组织对中国市场的关心。

  8. Impact of cellulose ethers on the cement paste microstructure

    OpenAIRE

    Pourchez, Jérémie; Grosseau, Philippe; Rouèche-Pourchez, Emilie; Debayle, Johan; Pinoli, Jean-Charles; Maire, Eric; Boller, Elodie; Parra-Denis, Estelle

    2007-01-01

    ISBN = 3-87264-022-4 7 pages; International audience; Complementary investigation tools (2D and 3D observations by optical microscopy and fast X-ray microtomography and then image analysis) were developed in order to examine the effects of cellulose ethers on the cement paste microstructure. The obtained results show that the presence of cellulose ether may induce an increase of both 50-250 µm-diameter air voids. The chemistry of the cellulose ethers appears as a main controlling factor of th...

  9. Synthesis and Adsorption Property of Dihydroxyl Azacrown Ether-Grafted Chitosan

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel dihydroxyl azacrown ether chitosan was synthesized by reacting dihydroxyl azacrown ether with epoxy activated chitosan. The adsorption property of the azacrown ether chitosan for Pb2+, Cr3+, and Ag+, were determined. The experimental results showed that the dihydroxyl azacrown ether grafted chitosan has high adsorption capacity and high selectivity for some metal ions.

  10. Le parole etrusche ame, amce e la revisione di IE. *yem- ‘paaren’

    Directory of Open Access Journals (Sweden)

    Adolfo Zavaroni

    2001-12-01

    Full Text Available The main purpose of this article is to demonstrate the groundlessness of the old and common thesis according to which Etr. ame, amuke, amce are parts of the verb “to be”. We can search for the true meaning of these words with the help of the so-called “comparative method”, a method that, in the last few decades, did not enjoy its due share of attention. My underlying thesis is that Etruscan, although not being an Indo-European language, has many IndoEuropean stems, which it acquired during many centuries of contacts. The comparative method might be of help just provided we strictly stick to the rules that define the phonological system of Etruscan (in the present work I present the system of the stops only. The term am(uce indicates ‘to be united, to make a pair with, co-’. In fact, amce is mainly found in connection with the words puia ‘wife’ and zilaθ (magistracy constituted by two or more persons. In extant inscriptions, we also find twice the word ame connected to puia, yet in most cases ame is a particle placed after the verb, where it fulfills the same function of the latin preverb cum, co-. As an example, in the Tabula Cortonensis the words eprus ame mean ‘co-operantur, (they sacrifice together’. Moreover, there are five occurrences of the particle ama connected with the word ipa. In my view, ipa … ama can be interpreted as ‘simul… cum’ = ‘pariter… cum’. There are further Etruscan words beginning with *am -that belong to the same root of ame, am(uce. See for example amθuras, amaνunice, amnu, aminθ. There is also a personage represented in several engravings on mirrors the name of whom is amuke, which is said to echo Greek Αμυκος. Nonetheless, amuke has indeed an Etruscan meaning. In order to explain such Germanic words as Got. ibns ‘eben’, Ags. efn, emn etc. and Lat. imitor, aemulus etc. the I-E root *yem- ‘paaren; to pair, match, couple’ was assumed. Anyhow, it can be smoothly replaced

  11. Genotoxicity evaluation of titanium dioxide nanoparticles using the Ames test and Comet assay.

    Science.gov (United States)

    Woodruff, Robert S; Li, Yan; Yan, Jian; Bishop, Michelle; Jones, M Yvonne; Watanabe, Fumiya; Biris, Alexandru S; Rice, Penelope; Zhou, Tong; Chen, Tao

    2012-11-01

    Titanium dioxide nanoparticles (TiO2-NPs) are being used increasingly for various industrial and consumer products, including cosmetics and sunscreens because of their photoactive properties. Therefore, the toxicity of TiO2-NPs needs to be thoroughly understood. In the present study, the genotoxicity of 10nm uncoated sphere TiO2-NPs with an anatase crystalline structure, which has been well characterized in a previous study, was assessed using the Salmonella reverse mutation assay (Ames test) and the single-cell gel electrophoresis (Comet) assay. For the Ames test, Salmonella strains TA102, TA100, TA1537, TA98 and TA1535 were preincubated with eight different concentrations of the TiO2-NPs for 4 h at 37 °C, ranging from 0 to 4915.2 µg per plate. No mutation induction was found. Analyses with transmission electron microscopy (TEM) and energy-dispersive X-ray spectroscopy (EDS) showed that the TiO2-NPs were not able to enter the bacterial cell. For the Comet assay, TK6 cells were treated with 0-200 µg ml(-1) TiO2-NPs for 24 h at 37 °C to detect DNA damage. Although the TK6 cells did take up TiO2-NPs, no significant induction of DNA breakage or oxidative DNA damage was observed in the treated cells using the standard alkaline Comet assay and the endonuclease III (EndoIII) and human 8-hydroxyguanine DNA-glycosylase (hOGG1)-modified Comet assay, respectively. These results suggest that TiO2-NPs are not genotoxic under the conditions of the Ames test and Comet assay.

  12. Genotoxicity of silver nanoparticles evaluated using the Ames test and in vitro micronucleus assay.

    Science.gov (United States)

    Li, Yan; Chen, David H; Yan, Jian; Chen, Ying; Mittelstaedt, Roberta A; Zhang, Yongbin; Biris, Alexandru S; Heflich, Robert H; Chen, Tao

    2012-06-14

    Silver nanoparticles (AgNPs) have antimicrobial properties, which have contributed to their widespread use in consumer products. A current issue regarding nanomaterials is the extent to which existing genotoxicity assays are useful for evaluating the risks associated with their use. In this study, the genotoxicity of 5 nm AgNPs was assessed using two standard genotoxicity assays, the Salmonella reverse mutation assay (Ames test) and the in vitro micronucleus assay. Using the preincubation version of the Ames assay, Salmonella strains TA102, TA100, TA1537, TA98, and TA1535 were treated with 0.15-76.8 μg/plate of the AgNPs. Toxicity limited the doses that could be assayed to 2.4-38.4 μg/plate; no increases in mutant frequency over the vehicle control were found for the concentrations that could be assayed. Human lymphoblastoid TK6 cells were treated with 10-30 μg/ml AgNPs, and additional cells were treated with water and 0.73 gy X-rays as vehicle and positive controls. Micronucleus frequency was increased by the AgNP treatment in a dose-dependent manner. At a concentration of 30 μg/ml (with 45.4% relative population doubling), AgNPs induced a significant, 3.17-fold increase with a net increase of 1.60% in micronucleus frequency over the vehicle control, a weak positive response by our criteria. These results demonstrate that the 5 nm AgNP are genotoxic in TK6 cells. Also, the data suggest that the in vitro micronucleus assay may be more appropriate than the Ames test for evaluating the genotoxicity of the AgNPs.

  13. Ames S-32 O-16 O-18 Line List for High-Resolution Experimental IR Analysis

    Science.gov (United States)

    Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.

    2016-01-01

    By comparing to the most recent experimental data and spectra of the SO2 628 ?1/?3 bands (see Ulenikov et al., JQSRT 168 (2016) 29-39), this study illustrates the reliability and accuracy of the Ames-296K SO2 line list, which is accurate enough to facilitate such high-resolution spectroscopic analysis. The SO2 628 IR line list is computed on a recently improved potential energy surface (PES) refinement, denoted Ames-Pre2, and the published purely ab initio CCSD(T)/aug-cc-pVQZ dipole moment surface. Progress has been made in both energy level convergence and rovibrational quantum number assignments agreeing with laboratory analysis models. The accuracy of the computed 628 energy levels and line list is similar to what has been achieved and reported for SO2 626 and 646, i.e. 0.01-0.03 cm(exp -1) for bands up to 5500 cm(exp -1). During the comparison, we found some discrepancies in addition to overall good agreements. The three-IR-list based feature-by-feature analysis in a 0.25 cm(exp -1) spectral window clearly demonstrates the power of the current Ames line lists with new assignments, correction of some errors, and intensity contributions from varied sources including other isotopologues. We are inclined to attribute part of detected discrepancies to an incomplete experimental analysis and missing intensity in the model. With complete line position, intensity, and rovibrational quantum numbers determined at 296 K, spectroscopic analysis is significantly facilitated especially for a spectral range exhibiting such an unusually high density of lines. The computed 628 rovibrational levels and line list are accurate enough to provide alternatives for the missing bands or suspicious assignments, as well as helpful to identify these isotopologues in various celestial environments. The next step will be to revisit the SO2 828 and 646 spectral analyses.

  14. Ames 32S16O18O line list for high-resolution experimental IR analysis

    Science.gov (United States)

    Huang, Xinchuan; Schwenke, David W.; Lee, Timothy J.

    2016-12-01

    By comparing to the most recent experimental data and spectra of the SO2 628 ν1/ν3 bands (see Ulenikov et al., JQSRT 168 (2016) 29-39), this study illustrates the reliability and accuracy of the Ames-296K SO2 line list, which is accurate enough to facilitate such high-resolution spectroscopic analysis. The SO2 628 IR line list is computed on a recently improved potential energy surface (PES) refinement, denoted Ames-Pre2, and the published purely ab initio CCSD(T)/aug-cc-pV(Q+d)Z dipole moment surface. Progress has been made in both energy level convergence and rovibrational quantum number assignments agreeing with laboratory analysis models. The accuracy of the computed 628 energy levels and line list is similar to what has been achieved and reported for SO2 626 and 646, i.e. 0.01-0.03 cm-1 for bands up to 5500 cm-1. During the comparison, we found some discrepancies in addition to overall good agreements. The three-IR-list based feature-by-feature analysis in a 0.25 cm-1 spectral window clearly demonstrates the power of the current Ames line lists with new assignments, correction of some errors, and intensity contributions from varied sources including other isotopologues. We are inclined to attribute part of detected discrepancies to an incomplete experimental analysis and missing intensity in the model. With complete line position, intensity, and rovibrational quantum numbers determined at 296 K, spectroscopic analysis is significantly facilitated especially for a spectral range exhibiting such an unusually high density of lines. The computed 628 rovibrational levels and line list are accurate enough to provide alternatives for the missing bands or suspicious assignments, as well as helpful to identify these isotopologues in various celestial environments. The next step will be to revisit the SO2 828 and 646 spectral analyses.

  15. NASA Ames Research Center R and D Services Directorate Biomedical Systems Development

    Science.gov (United States)

    Pollitt, J.; Flynn, K.

    1999-01-01

    The Ames Research Center R&D Services Directorate teams with NASA, other government agencies and/or industry investigators for the development, design, fabrication, manufacturing and qualification testing of space-flight and ground-based experiment hardware for biomedical and general aerospace applications. In recent years, biomedical research hardware and software has been developed to support space-flight and ground-based experiment needs including the E 132 Biotelemetry system for the Research Animal Holding Facility (RAHF), E 100 Neurolab neuro-vestibular investigation systems, the Autogenic Feedback Systems, and the Standard Interface Glove Box (SIGB) experiment workstation module. Centrifuges, motion simulators, habitat design, environmental control systems, and other unique experiment modules and fixtures have also been developed. A discussion of engineered systems and capabilities will be provided to promote understanding of possibilities for future system designs in biomedical applications. In addition, an overview of existing engineered products will be shown. Examples of hardware and literature that demonstrate the organization's capabilities will be displayed. The Ames Research Center R&D Services Directorate is available to support the development of new hardware and software systems or adaptation of existing systems to meet the needs of academic, commercial/industrial, and government research requirements. The Ames R&D Services Directorate can provide specialized support for: System concept definition and feasibility Mathematical modeling and simulation of system performance Prototype hardware development Hardware and software design Data acquisition systems Graphical user interface development Motion control design Hardware fabrication and high-fidelity machining Composite materials development and application design Electronic/electrical system design and fabrication System performance verification testing and qualification.

  16. Evaluation of crystallization kinetics of poly (ether-ketone-ketone and poly (ether-ether-ketone by DSC

    Directory of Open Access Journals (Sweden)

    Gibran da Cunha Vasconcelos

    2010-08-01

    Full Text Available The poly (aryl ether ketones are used as matrices in advanced composites with high performance due to its high thermal stability, excellent environmental performance and superior mechanical properties. Most of the physical, mechanical and thermodynamic properties of semi-crystalline polymers depend on the degree of crystallinity and morphology of the crystalline regions. Thus, a study on the crystallization process promotes a good prediction of how the manufacturing parameters affect the developed structure, and the properties of the final product. The objective of this work was to evaluate the thermoplastics polymers PEKK e PEEK by DSC, aiming to obtain the relationship between kinetics, content, nucleation and geometry of the crystalline phases, according to the parameters of the Avrami and Kissinger models. The analysis of the Avrami exponents obtained for the studied polymers indicates that both showed the formation of crystalline phases with heterogeneous nucleation and growth geometry of the type sticks or discs, depending on the cooling conditions. It was also found that the PEEK has a higher crystallinity than PEKK.

  17. Spatial trends of polybrominated diphenyl ether (PBDE) congeners

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spatial trends of polybrominated diphenyl ether (PBDE) congeners were analyzed in young of the year bluefish collected along the U.S. Atlantic coastline from...

  18. Fluorinated Alkyl Ether Epoxy Resin Compositions and Applications Thereof

    Science.gov (United States)

    Wohl, Christopher J. (Inventor); Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Siochi, Emilie J. (Inventor); Gardner, John M. (Inventor); Palmieri, Frank M. (Inventor)

    2017-01-01

    Epoxy resin compositions prepared using amino terminated fluoro alkyl ethers. The epoxy resin compositions exhibit low surface adhesion properties making them useful as coatings, paints, moldings, adhesives, and fiber reinforced composites.

  19. Changes of Ovarian microRNA Profile in Long-Living Ames Dwarf Mice during Aging

    OpenAIRE

    Schneider, Augusto; Scot J. Matkovich; Victoria, Berta; Spinel, Lina; Bartke, Andrzej; Golusinski, Pawel; Masternak, Michal M.

    2017-01-01

    The Ames dwarf (df/df) mice have extended longevity and can preserve the ovarian reserve longer than Normal (N) mice. Based on this, the aim of our study was to evaluate the ovarian microRNA (miRNA) profile in young and aged df/df and N mice. Ovarian tissue was collected at 5–6 months and at 21–22 months of age for miRNA sequencing. We detected a total of 404 miRNAs in the ovarian samples, from which the abundance of 22 and 33 miRNAs changed with age in N and df/df mice, respectively. Of thes...

  20. An evaluation of instant and regular coffee in the Ames mutagenicity test.

    Science.gov (United States)

    Aeschbacher, H U; Würzner, H P

    1980-02-01

    High concentrations of "home brew" and instant coffe induced revertants 2--3-fold the spontaneous level with the Ames Salmonella tester strain TA 100 but not with the strains TA 98, TA 1535, TA 1537 and TA 1538. This borderline effect, which may also have been due to non-mutagenic interactions (false positives) occurred only at bacterial levels of coffees and was completely abolished in the presence of the microsomal "metabolic activation system". Negative results were obtained in host-mediated assays when mice received up to 6 g instant coffee/kg body weight. An extrapolation in respect of possible carcinogenic risks is dubious.

  1. Recent Progress in Entry Radiation Measurements in the NASA Ames Electric ARC Shock Tube Facility

    Science.gov (United States)

    Cruden, Brett A.

    2012-01-01

    The Electric Arc Shock Tube (EAST) at NASA Ames Research Center is NASA's only working shock tube capable of obtaining conditions representative of entry in a multitude of planetary atmospheres. The facility is capable of mapping spectroscopic signatures of a wide range of planetary entries from the Vacuum Ultraviolet through Mid-Wave Infrared (120-5500 nm). This paper summarizes the tests performed in EAST for Earth, Mars and Venus entries since 2008, then focuses on a specific test case for CO2/N2 mixtures. In particular, the paper will focus on providing information for the proper interpretation of the EAST data.

  2. Testing of SLA-561V in NASA-Ames' Turbulent Flow Duct with Augmented Radiative Heating

    Science.gov (United States)

    Sepka, Steven A.; Kornienko, Robert S.; Radbourne, Chris A.

    2010-01-01

    As part of Mars Science Laboratory s (MSL) heatshield development program, SLA-561 was tested in NASA Ames Turbulent Flow Duct (TFD) Facility. For these tests, the TFD facility was modified to include a ceramic plate located in the wall opposite to the test model. Normally the TFD wall opposite to the test model is water-cooled steel. Installing a noncooled ceramic plate allows the ceramic to absorb convective heating and radiate the energy back to the test model as the plate heats up. This work was an effort to increase the severity of TFD test conditions. Presented here are the results from these tests.

  3. Study of optical techniques for the Ames unitary wind tunnels. Part 4: Model deformation

    Science.gov (United States)

    Lee, George

    1992-01-01

    A survey of systems capable of model deformation measurements was conducted. The survey included stereo-cameras, scanners, and digitizers. Moire, holographic, and heterodyne interferometry techniques were also looked at. Stereo-cameras with passive or active targets are currently being deployed for model deformation measurements at NASA Ames and LaRC, Boeing, and ONERA. Scanners and digitizers are widely used in robotics, motion analysis, medicine, etc., and some of the scanner and digitizers can meet the model deformation requirements. Commercial stereo-cameras, scanners, and digitizers are being improved in accuracy, reliability, and ease of operation. A number of new systems are coming onto the market.

  4. Study of optical techniques for the Ames unitary wind tunnels. Part 1: Schlieren

    Science.gov (United States)

    Lee, George

    1992-01-01

    Alignment procedures and conceptual designs for the rapid alignment of the Ames Unitary Wind Tunnel schlieren systems were devised. The schlieren systems can be aligned by translating the light source, the mirrors, and the knife edge equal distances. One design for rapid alignment consists of a manual pin locking scheme. The other is a motorized electronic position scheme. A study of two optical concepts which can be used with the schlieren system was made. These are the 'point diffraction interferometers' and the 'focus schlieren'. Effects of vibrations were studied.

  5. Global biology - An interdisciplinary scientific research program at NASA, Ames Research Center

    Science.gov (United States)

    Lawless, J. G.; Colin, L.

    1983-01-01

    NASA has initiated new effort in Global Biology, the primary focus of which is to understand biogeochemical cycles. As part of this effort, an interdisciplinary team of scientists has formed at Ames Research Center to investigate the cycling of sulfur in the marine coastal zone and to study the cycling of nitrogen in terrestrial ecosystems. Both studies will use remotely sensed data, coupled with ground-based research, to identify and measure the transfer of major and minor biologically produced gases between these ecosystems and global reservoirs.

  6. Global Biology: An Interdisciplinary Scientific Research Program at NASA Ames Research Center

    Science.gov (United States)

    Lawless, James G.; Colin, Lawrence

    1984-01-01

    NASA has initiated new effort in Global Biology, the primary focus of which is to understand biogeochemical cycles. As part of this effort, an interdisciplinary team of scientists has formed at Ames Research Center to investigate the cycling of sulfur in the marine coastal zone and to study the cycling of nitrogen in terrestrial ecosystems. Both studies will use remotely sensed data, coupled with ground-based research, to identify and measure the transfer of major and minor biologically produced gases between these ecosystems and global reservoirs.

  7. 德国赫优讯EtherCAT产品

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    德国赫优讯自动化系统有限公司作为EtherCAT国际组织的重要成员之一,推出基于实时以太网EtherCAT的计算机通信板卡cifX系列产品和嵌入式通信模块comX系列产品。

  8. Nickel-catalyzed direct synthesis of dialkoxymethane ethers

    Indian Academy of Sciences (India)

    MURUGAN SUBARAMANIAN; ABHIJIT BERA; BHAGAVATULA L V PRASAD; EKAMBARAM BALARAMAN

    2017-08-01

    A simple and efficient method for the preparation of dialkoxymethane ethers (oxymethylene ethers) from alcohols and paraformaldehyde in the presence of commercially available nickel(II) salt is described. The reaction proceeds readily under neutral, solvent-free conditions using paraformaldehyde as a C1 source. The present strategy has a broad substrate scope including aliphatic (both primary and secondary) and aromatic alcohols and provides a benign method for the preparation of symmetrical dialkoxymethanes in good yields (up to 89%).

  9. Imide/Arylene Ether Copolymers Containing Phosphine Oxide

    Science.gov (United States)

    Jensen, Brian J.; Partos, Richard D.

    1993-01-01

    Phosphine oxide groups react with oxygen to form protective phosphate surface layers. Series of imide/arylene ether block copolymers containing phosphine oxide units in backbone synthesized and characterized. In comparison with commercial polyimide, these copolymers display better resistance to etching by oxygen plasma. Tensile strengths and tensile moduli greater than those of polyarylene ether homopolymer. Combination of properties makes copolymers attractive for films, coatings, adhesives, and composite matrices where resistance to atomic oxygen needed.

  10. Marine Sponge Dysidea herbacea revisited: Another Brominated Diphenyl Ether

    Directory of Open Access Journals (Sweden)

    Bruce F. Bowden

    2005-03-01

    Full Text Available Abstract: A pentabrominated phenolic diphenyl ether (1 that has not previously been reported from marine sources has been isolated from Dysidea herbacea collected at Pelorus Island, Great Barrier Reef, Australia. The structure was determined by comparison of NMR data with those of known structurally-related metabolites. NMR spectral assignments for (1 are discussed in context with those of three previously reported isomeric pentabrominated phenolic diphenyl ethers.

  11. Effect of diethyl ether on the biliary excretion of acetaminophen.

    Science.gov (United States)

    Watkins, J B; Siegers, C P; Klaassen, C D

    1984-10-01

    The biliary and renal excretion of acetaminophen and its metabolites over 8 hr was determined in rats exposed to diethyl ether by inhalation for 1 hr. Additional rats were anesthetized with urethane (1 g/kg ip) while control animals were conscious throughout the experiment (surgery was performed under hexobarbital narcosis: 150 mg/kg ip; 30-min duration). The concentration of UDP-glucuronic acid was decreased 80% in livers from ether-anesthetized rats but was not reduced in urethane-treated animals when compared to that in control rats. The concentration of reduced glutathione was not affected by either urethane or diethyl ether. Basal bile flow was not altered by the anesthetic agents. Bile flow rate after acetaminophen injection (100 mg/kg iv) was increased slightly over basal levels for 2 hr in hexobarbital-treated control rats, was unaltered in urethane-anesthetized animals, and was decreased throughout the 8-hr experiment in rats exposed to diethyl ether for 1 hr. In control and urethane-anesthetized animals, approximately 30-35% of the total acetaminophen dose (100 mg/kg iv) was excreted into bile in 8 hr, while only 16% was excreted in rats anesthetized with diethyl ether. Urinary elimination (60-70% of the dose) was not altered by exposure to ether. Separation of metabolites by reverse-phase high-pressure liquid chromatography showed that ether decreased the biliary elimination of unchanged acetaminophen and its glucuronide, sulfate, and glutathione conjugates by 47, 40, 49, and 73%, respectively, as compared to control rats. Excretion of unchanged acetaminophen and the glutathione conjugate into bile was depressed in urethane-anesthetized animals by 45 and 66%, respectively, whereas elimination of the glucuronide and sulfate conjugates was increased by 27 and 50%, respectively. These results indicate that biliary excretion is influenced by the anesthetic agent and that diethyl ether depresses conjugation with sulfate and glutathione as well as glucuronic

  12. Advanced hybrid fluoropolymers from the cycloaddition of aryl trifluorovinyl ethers

    Science.gov (United States)

    Ligon, S. Clark, Jr.

    This dissertation discusses the synthesis of aryl trifluorovinyl ethers and their cycloaddition polymerization to give perfluorocyclobutyl (PFCB) polymers. To explore the stereochemistry of these polymers, simple monomfunctional aryl trifluorovinyl ethers were dimerized and the resultant cis and trans isomers were separated. Differences in structure help to improve understanding of the amorphous nature of the bulk PFCB polymeric material. To apply this knowledge, crown ether containing perfluorocyclobutyl (PFCB) polymers were synthesized for use in lithium ion battery applications. While poor solubility has hindered further development of these materials, slight modifications to structure may provide a solution. Also described is a fluorinated aryl vinyl ether and its attempted copolymerization with chlorotrifluoroethylene. While this copolymerization did not yield the desired materials, novel semifluorinated phenol precursors have been utilized in reactions with carboxylic acids to give polyesters and most recently with phosgene like species to give polycarbonates. Next, PFCB polymers were post functionalized with fluoroalkyl tethers to improve oleophobicity and hydrophobicity without decreasing thermal stability or optical clarity. In addition, various silica nanostructures were functionalized with aryl trifluorovinyl ethers. This includes the reaction of aryl silanes to give trifluorovinyl ether functional POSS and their polymerization to provide PFCB hybrid materials. Silane coupling agents were also used to functionalize colloidal silica and fumed silica nanoparticles. These procedures allow excellent dispersion of the silica nanoparticles throughout the fluoropolymer matrix. Finally, the reaction of aryl trifluorovinyl ether with nonfluorinated alkenes and alkynes was explored. In these reactions, the fluorinated olefin adds with the hydrocarbon olefin to give semifluorinated cyclobutanes (SFCB) and with the alkyne to give semifluorinated cyclobutene. The

  13. Effects of the ether phospholipid AMG-PC on mast cells are similar to that of the ether lipid AMG but different from that of the analogue hexadecylphosphocholine

    DEFF Research Database (Denmark)

    Grosman, Nina

    1991-01-01

    Farmakologi, ether phospholipid, hexacylphosphocholine, miltefosine, protein kinase C, AMG-PC(alkyl-methyl-glycero-phosphocholine), Histamine release, mast cell......Farmakologi, ether phospholipid, hexacylphosphocholine, miltefosine, protein kinase C, AMG-PC(alkyl-methyl-glycero-phosphocholine), Histamine release, mast cell...

  14. Review on Modification of Sulfonated Poly (-ether-ether-ketone Membranes Used as Proton Exchange Membranes

    Directory of Open Access Journals (Sweden)

    Xiaomin GAO

    2015-11-01

    Full Text Available The proton exchange membrane fuel cell (PEMFC is a type of modern power, but the traditional proton exchange membranes (PEM of PEMFC are limited by high methanol permeability and water uptake. Poly-ether-ether-ketone (PEEK is a widely used thermoplastic with good cost-effective property. Sulfonated poly (-ether-ether-ketone (SPEEK has high electric conductivity and low methanol permeability, as well as comprehensive property, which is expected to be used as PEMs. However, the proton exchange ability, methanol resistance, mechanical property and thermal stability of SPEEK are closely related to the degree of sulfonation (DS of SPEEK membranes. Additionally, the proton conductivity, methanol permeability, and stability of SPEEK membranes applied in various conditions need to be further improved. In this paper, the research into modification of SPEEK membranes made by SPEEK and other polymers, inorganic materials are introduced. The properties and modification situation of the SPEEK and the composite membranes, as well as the advantages and disadvantages of membranes prepared by different materials are summarized. From the results we know that, the methanol permeability of SPEEK/PES-C membranes is within the order of magnitude, 10-7cm2/s. The proton conductivity of the SPPESK/SPEEK blend membrane reaches 0.212 S cm-1 at 80 °C. The cross-linked SPEEK membranes have raised thermal and dimensional stability. The non-solvent caused aggregation of the SPEEK ionomers. The proton conductivity of SPEEK/50%BMIMPF6/4.6PA membrane maintains stable as 2.0 x 10-2S cm-1 after 600 h at 160 °C. Incorporation of aligned CNT into SPEEK increases the proton conductivity and reduces the methanol permeability of the composite membranes. The PANI improves the hydrothermal stability. More proton transfer sites lead to a more compact structure in the composite membranes. According to the results, the proton exchange capacity, water uptake, and conductivity of

  15. Conversion of dimethyl ether on zeolite catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Abramova, A.V.; Kulumbegov, R.V.; Khadzhiev, S.N. [Russian Academy of Sciences, Moscow (Russian Federation). A.V. Topchiev Inst. of Petrochemical Synthesis

    2006-07-01

    Catalytic conversion of dimethyl ether to hydrocarbons was investigated using zeolite catalyst ZSM-5 type. 2% MexOy - 60% HZVM(analogue of ZSM-5)/Al{sub 2}O{sub 3}, (Me = Zn, Ga, Fe, Co, V, Ni) catalyst samples have been obtained. The reaction was carried out in a fixed bed reaction set-up at 350-400 C, pressure 3 MPa, gas mix (% vol.): 24 DME, 76 N{sub 2}, WHSV=1300 l/l-{sub kat.}h. Most effective catalysts of DME conversion are pentasil based catalysts with promoter metals zinc, iron and cobalt by totality DME-conversion, gas and liquid hydrocarbon selectivity, ethylene and propylene content in gas. The best work temperatures are 350 and 375 C, thereupon increasing of temperature to 400 C leads to considerable growth of methane in hydrocarbon gas. Liquid hydrocarbons have high content of aromatics and iso-paraffins. Liquid hydrocarbon product is characterized by high octane number (RON) 90-98. (orig.)

  16. Dimethyl ether (DME) as an alternative fuel

    Science.gov (United States)

    Semelsberger, Troy A.; Borup, Rodney L.; Greene, Howard L.

    With ever growing concerns on environmental pollution, energy security, and future oil supplies, the global community is seeking non-petroleum based alternative fuels, along with more advanced energy technologies (e.g., fuel cells) to increase the efficiency of energy use. The most promising alternative fuel will be the fuel that has the greatest impact on society. The major impact areas include well-to-wheel greenhouse gas emissions, non-petroleum feed stocks, well-to-wheel efficiencies, fuel versatility, infrastructure, availability, economics, and safety. Compared to some of the other leading alternative fuel candidates (i.e., methane, methanol, ethanol, and Fischer-Tropsch fuels), dimethyl ether appears to have the largest potential impact on society, and should be considered as the fuel of choice for eliminating the dependency on petroleum. DME can be used as a clean high-efficiency compression ignition fuel with reduced NO x, SO x, and particulate matter, it can be efficiently reformed to hydrogen at low temperatures, and does not have large issues with toxicity, production, infrastructure, and transportation as do various other fuels. The literature relevant to DME use is reviewed and summarized to demonstrate the viability of DME as an alternative fuel.

  17. Polybrominated diphenyl ethers and novel flame retardants

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Vorkamp, Katrin; Nielsen, Jesper Bo

    ,4,6-tribromophenyl ether (TBP-DBPE) and dechlorane plus (DDC-CO) have been detected in the same dust samples previously analysed for PBDEs and are currently being analysed in the corresponding human milk samples. [1] Stapleon H.M., Eagle S., Sjödin A., Webster T.F. (2012). Serum PBDEs in a North Carolina Toddler......, the objectives were to study whether i) the associations observed for plasma also existed for human milk, ii) the PBDE profiles in dust and milk could provide insights into the bioavailability and bioaccumulation of individual congeners, iii) NFRs were measurable in human milk, and iv) infants were exposed...... to significant amounts of NFRs via breast feeding. PBDEs were detected in all of the 40 milk samples analysed in this study. ΣPBDEtri-hepta ranged from 0.98-45.8 ng/g lw, with a median of 2.26 ng/g lw. The main congener in milk was BDE-153, accounting for 35% of ΣPBDEtri-hepta. This is much higher than in dust...

  18. Molecular Design of Crown Ethers.22.Synthesis of Benzocrown Ether Derivatives and Their Solvent Extraction with Univalent/Bivalent Metal Picrates

    Institute of Scientific and Technical Information of China (English)

    YANG,Ying-Wei(杨英威); LI,Chun-Ju(李春举); ZHANG,Heng-Yi(张衡益); LIU,Yu(刘育)

    2004-01-01

    Three novel benzocrown ether derivatives have been synthesized and their cation binding behavior with uniand bi-valent metal ions was evaluated by the solvent extraction of aqueous metal picrates. The obtained results indicate that the size-fit of crown ether and metal cation, and electron effect of the side arm attached to benzocrown ethers affect their cation binding ability and selectivity.

  19. Recent Advancements in the Infrared Flow Visualization System for the NASA Ames Unitary Plan Wind Tunnels

    Science.gov (United States)

    Garbeff, Theodore J., II; Baerny, Jennifer K.

    2017-01-01

    The following details recent efforts undertaken at the NASA Ames Unitary Plan wind tunnels to design and deploy an advanced, production-level infrared (IR) flow visualization data system. Highly sensitive IR cameras, coupled with in-line image processing, have enabled the visualization of wind tunnel model surface flow features as they develop in real-time. Boundary layer transition, shock impingement, junction flow, vortex dynamics, and buffet are routinely observed in both transonic and supersonic flow regimes all without the need of dedicated ramps in test section total temperature. Successful measurements have been performed on wing-body sting mounted test articles, semi-span floor mounted aircraft models, and sting mounted launch vehicle configurations. The unique requirements of imaging in production wind tunnel testing has led to advancements in the deployment of advanced IR cameras in a harsh test environment, robust data acquisition storage and workflow, real-time image processing algorithms, and evaluation of optimal surface treatments. The addition of a multi-camera IR flow visualization data system to the Ames UPWT has demonstrated itself to be a valuable analyses tool in the study of new and old aircraft/launch vehicle aerodynamics and has provided new insight for the evaluation of computational techniques.

  20. Consolidated Laser-Induced Fluorescence Diagnostic Systems for the NASA Ames Arc Jet Facilities

    Science.gov (United States)

    Grinstead, Jay H.; Wilder, Michael C.; Porter, Barry J.; Brown, Jeffrey D.; Yeung, Dickson; Battazzo, Stephen J.; Brubaker, Timothy R.

    2016-01-01

    The spectroscopic diagnostic technique of two photon absorption laser-induced fluorescence (LIF) of atomic species for non-intrusive arc jet flow property measurement was first implemented at NASA Ames in the mid-1990s. In 2013-2014, NASA combined the agency's large-scale arc jet test capabilities at NASA Ames. Concurrent with that effort, the agency also sponsored a project to establish two comprehensive LIF diagnostic systems for the Aerodynamic Heating Facility (AHF) and Interaction Heating Facility (IHF) arc jets. The scope of the project enabled further engineering development of the existing IHF LIF system as well as the complete reconstruction of the AHF LIF system. The updated LIF systems are identical in design and capability. They represent the culmination of over 20 years of development experience in transitioning a specialized laboratory research tool into a measurement system for large-scale, high-demand test facilities. This paper will document the latest improvements of the LIF system design and demonstrations of the redeveloped AHF and IHF LIF systems.

  1. Genotoxic evaluation of Halfenprox using the human peripheral lymphocyte micronucleus assay and the Ames test.

    Science.gov (United States)

    Akyıl, Dilek; Eren, Yasin; Konuk, Muhsin; Dere, Hatice; Serteser, Ahmet

    2017-04-01

    The genotoxicity and mutagenicity of Halfenprox, a synthetic pyrethroid insecticide and acaricide, was assessed using two standard genotoxicity assays of the Salmonella typhimurium mutagenicity assay (Ames test) and in vitro micronucleus (MN) assay in human peripheral lymphocytes. In the Ames test, Salmonella strains TA98 and TA100 were treated with or without S9 fraction. The doses of Halfenprox were 6.25, 12.5, 25, 50, and 100 μg/plate and test materials were dissolved in DMSO. The concentrations of Halfenprox did not show mutagenic activity on both strains with and without S9 fraction. The MN assay was used to investigate the genotoxic effects of Halfenprox in human peripheral lymphocytes treated with 250, 500, 750, and 1000 μg/ml concentrations of Halfenprox for 24 and 48 h, and at 1000 μg/ml the concentration was significantly increased and the MN formation was compared with the negative control for both treatment periods. In addition, a significant decrease of the nuclear devision index (NDI) values at the higher concentrations of Halfenprox and at both treatment periods was observed.

  2. Are effects of common ragwort in the Ames test caused by pyrrolizidine alkaloids?

    Science.gov (United States)

    Bovee, Toine F H; Helsdingen, Richard J R; Hoogenboom, Ron L A P; de Nijs, Monique W C M; Liu, Xiaojie; Vrieling, Klaas; Klinkhamer, Peter G L; Peijnenburg, Ad A C M; Mulder, Patrick P J

    2015-08-01

    It has previously been demonstrated by others that acetone extracts of Senecio jacobaea (syn. Jacobaea vulgaris, common or tansy ragwort) test positive in the Salmonella/microsome mutagenicity test (Ames test). Pyrrolizidine alkaloids (PAs) are thought to be responsible for these mutagenic effects. However, it was also observed that the major PA present in common ragwort, jacobine, produced a negative response (with and without the addition of rat liver S9) in Salmonella test strains TA98, TA100, TA1535 and TA1537. To investigate which compounds in the plant extracts were responsible for the positive outcome, the present study investigated the contents and mutagenic effects of methanol and acetone extracts prepared from dried ground S. jacobaea and Senecio inaequidens (narrow-leafed ragwort). Subsequently, a fractionation approach was set up in combination with LC-MS/MS analysis of the fractions. It was shown that the positive Ames test outcomes of S. jacobaea extracts are unlikely to be caused by PAs, but rather by the flavonoid quercetin. This study also demonstrates the importance of identifying compounds responsible for positive test results in bioassays.

  3. Effects of growth hormone and thyroxine replacement therapy on insulin signaling in Ames dwarf mice.

    Science.gov (United States)

    Louis, Audreen; Bartke, Andrzej; Masternak, Michal M

    2010-04-01

    Ames dwarf (Prop1(df), df/df) mice lack growth hormone (GH), prolactin, and thyrotropin and live remarkably longer than their normal siblings. Significance of reduced activity of the somatotropic and thyroid axes during development and adulthood on longevity are unknown. Because enhanced insulin sensitivity and reduced insulin levels are among likely mechanisms responsible for increased longevity in these mutants, we compared the effects of GH and thyroxine (T4) replacement on various parameters related to insulin signaling in young and old male df/df mice. The results suggest that altered plasma adiponectin and insulin-like growth factor-1 (IGF-1) and hepatic IGF-1, insulin receptor (IR), IR substrate-1, peroxisome proliferator-activated receptor (PPAR) gamma, and PPARgamma coactivator-1 alpha may contribute to increased insulin sensitivity in Ames dwarfs. The stimulatory effect of GH and T4 treatment on plasma insulin and inhibitory effect on expression of hepatic glucose transporter-2 were greater in old than in young dwarfs. These results indicate that GH and T4 treatment has differential impact on insulin signaling during development and adulthood.

  4. Thyroxine modifies the effects of growth hormone in Ames dwarf mice

    Science.gov (United States)

    Do, Andrew; Menon, Vinal; Zhi, Xu; Gesing, Adam; Wiesenborn, Denise S.; Spong, Adam; Sun, Liou; Bartke, Andrzej; Masternak, Michal M.

    2015-01-01

    Ames dwarf (df/df) mice lack growth hormone (GH), thyroid stimulating hormone and prolactin. Treatment of juvenile df/df mice with GH alone stimulates somatic growth, reduces insulin sensitivity and shortens lifespan. Early‐life treatment with thyroxine (T4) alone produces modest growth stimulation but does not affect longevity. In this study, we examined the effects of treatment of juvenile Ames dwarf mice with a combination of GH + T4 and compared them to the effects of GH alone. Treatment of female and male dwarfs with GH + T4 between the ages of 2 and 8 weeks rescued somatic growth yet did not reduce lifespan to match normal controls, thus contrasting with the previously reported effects of GH alone. While the male dwarf GH + T4 treatment group had no significant effect on lifespan, the female dwarfs undergoing treatment showed a decrease in maximal longevity. Expression of genes related to GH and insulin signaling in the skeletal muscle and white adipose tissue (WAT) of female dwarfs was differentially affected by treatment with GH + T4 vs. GH alone. Differences in the effects of GH + T4 vs. GH alone on insulin target tissues may contribute to the differential effects of these treatments on longevity. PMID:25935838

  5. The contribution of visceral fat to improved insulin signaling in Ames dwarf mice

    Science.gov (United States)

    Menon, Vinal; Zhi, Xu; Hossain, Tanvir; Bartke, Andrzej; Spong, Adam; Gesing, Adam; Masternak, Michal M

    2014-01-01

    Ames dwarf (Prop1df, df/df) mice are characterized by growth hormone (GH), prolactin, and thyrotropin deficiency, remarkable extension of longevity and increased insulin sensitivity with low levels of fasting insulin and glucose. Plasma levels of anti-inflammatory adiponectin are increased in df/df mice, while pro-inflammatory IL-6 is decreased in plasma and epididymal fat. This represents an important shift in the balance between pro- and anti-inflammatory adipokines in adipose tissue, which was not exposed to GH signals during development or adult life. To determine the role of adipose tissue in the control of insulin signaling in these long-living mutants, we examined the effects of surgical removal of visceral (epididymal and perinephric) adipose tissue. Comparison of the results obtained in df/df mice and their normal (N) siblings indicated different effects of visceral fat removal (VFR) on insulin sensitivity and glucose tolerance. The analysis of the expression of genes related to insulin signaling indicated that VFR improved insulin action in skeletal muscle in N mice. Interestingly, this surgical intervention did not improve insulin signaling in df/df mice skeletal muscle but caused suppression of the signal in subcutaneous fat. We conclude that altered profile of adipokines secreted by visceral fat of Ames dwarf mice may act as a key contributor to increased insulin sensitivity and extended longevity of these animals. PMID:24690289

  6. The contribution of visceral fat to improved insulin signaling in Ames dwarf mice.

    Science.gov (United States)

    Menon, Vinal; Zhi, Xu; Hossain, Tanvir; Bartke, Andrzej; Spong, Adam; Gesing, Adam; Masternak, Michal M

    2014-06-01

    Ames dwarf (Prop1(df), df/df) mice are characterized by growth hormone (GH), prolactin, and thyrotropin deficiency, remarkable extension of longevity and increased insulin sensitivity with low levels of fasting insulin and glucose. Plasma levels of anti-inflammatory adiponectin are increased in df/df mice, while pro-inflammatory IL-6 is decreased in plasma and epididymal fat. This represents an important shift in the balance between pro- and anti-inflammatory adipokines in adipose tissue, which was not exposed to GH signals during development or adult life. To determine the role of adipose tissue in the control of insulin signaling in these long-living mutants, we examined the effects of surgical removal of visceral (epididymal and perinephric) adipose tissue. Comparison of the results obtained in df/df mice and their normal (N) siblings indicated different effects of visceral fat removal (VFR) on insulin sensitivity and glucose tolerance. The analysis of the expression of genes related to insulin signaling indicated that VFR improved insulin action in skeletal muscle in N mice. Interestingly, this surgical intervention did not improve insulin signaling in df/df mice skeletal muscle but caused suppression of the signal in subcutaneous fat. We conclude that altered profile of adipokines secreted by visceral fat of Ames dwarf mice may act as a key contributor to increased insulin sensitivity and extended longevity of these animals. © 2014 The Authors. Aging Cell published by the Anatomical Society and John Wiley & Sons Ltd.

  7. Ames Mutagenicity Assessment of Flavored Water Pipe Tobacco Products :A Cross Sectional Study in Tehran

    Directory of Open Access Journals (Sweden)

    Shahrzad Sadri

    2016-12-01

    Full Text Available Waterpipe smoking has become a global youth trend especially in the Middle East countries and Iran . The aim of this study was to determine the mutagenic effects of three most popular flavored tobaccos by four different salmonella typhimurium strains and compare the possible mutagenic effects of the test samples. Ames mutagenicity assessment was conducted according to the OECD guideline using TA100, TA98 , YG1024 and YG1029 strains. Charcoal burned flavored tobaccos of three different flavors including Orange, Double Apple, and Lime Mint were filtered and exposed to all strains after strain identification tests and MIC ,MBC determinations. The Ames test results indicated significant mutagenic effects of tobacco samples in all four test strains when compared with negative control (p≤0.0001. The highest Mutagenic Factor (MF was seen in Double Apple samples using TA 98 (MF=11.5±3.3 . In all experiments, TA strains showed higher sensitivity to the samples than YG strains which suggest these two strains for further regulatory toxicity tests ,policy making purposes and tobacco control programs . Present results represents an important step in understanding the genotoxic potentials of three most popular flavored tobaccos samples of a famous brand in the global markets .

  8. Assessment of diphenylcyclopropenone for photochemically induced mutagenicity in the Ames assay

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, M.G.; Connor, T.H.; Henkin, J.; Wilkin, J.K.; Matney, T.S.

    1987-10-01

    The photochemical conversion of diphenylcyclopropenone to diphenylacetylene has recently been reported. Diphenylcyclopropenone is used in the treatment of alopecia areata and is nonmutagenic in a limited Ames assay. We examined diphenylcyclopropenone and diphenylacetylene, as well as synthetic precursors of diphenylcyclopropenone--dibenzylketone and alpha,alpha'-dibromodibenzylketone--for mutagenicity against TA100, TA98, TA102, UTH8413, and UTH8414. All compounds were nonmutagenic except alpha,alpha'-dibromodibenzylketone, which was a potent mutagen in TA100 with and without S-9 activation. The effect of photochemical activation of diphenylcyclopropenone in the presence of bacteria demonstrated mutagenicity in UTH8413 (two times background) at 10 micrograms/plate with S-9 microsomal activation. 8-Methoxypsoralen produces a mutagenic response in TA102 at 0.1 microgram/plate with 60 seconds of exposure to 350 nm light. In vitro photochemically activated Ames assay with S-9 microsomal fraction may enhance the trapping of short-lived photochemically produced high-energy mutagenic intermediates. This technique offers exciting opportunities to trap high-energy intermediates that may play an important role in mutagenesis. This method can be applied to a variety of topically applied dermatologic agents, potentially subjected to photochemical changes in normal use.

  9. The Effects of Sulfonated Poly(ether ether ketone Ion Exchange Preparation Conditions on Membrane Properties

    Directory of Open Access Journals (Sweden)

    Rebecca S. L. Yee

    2013-08-01

    Full Text Available A low cost cation exchange membrane to be used in a specific bioelectrochemical system has been developed using poly(ether ether ketone (PEEK. This material is presented as an alternative to current commercial ion exchange membranes that have been primarily designed for fuel cell applications. To increase the hydrophilicity and ion transport of the PEEK material, charged groups are introduced through sulfonation. The effect of sulfonation and casting conditions on membrane performance has been systematically determined by producing a series of membranes synthesized over an array of reaction and casting conditions. Optimal reaction and casting conditions for producing SPEEK ion exchange membranes with appropriate performance characteristics have been established by this uniquely systematic experimental series. Membrane materials were characterized by ion exchange capacity, water uptake, swelling, potential difference and NMR analysis. Testing this extensive membranes series established that the most appropriate sulfonation conditions were 60 °C for 6 h. For mechanical stability and ease of handling, SPEEK membranes cast from solvent casting concentrations of 15%–25% with a resulting thickness of 30–50 µm were also found to be most suitable from the series of tested casting conditions. Drying conditions did not have any apparent impact on the measured parameters in this study. The conductivity of SPEEK membranes was found to be in the range of 10−3 S cm−1, which is suitable for use as a low cost membrane in the intended bioelectrochemical systems.

  10. Molecular sieve/sulfonated poly(ether ketone ether sulfone) composite membrane as proton exchange membrane

    Science.gov (United States)

    Changkhamchom, Sairung; Sirivat, Anuvat

    2012-02-01

    A proton exchange membrane (PEM) is an electrolyte membrane used in both polymer electrolyte membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFCs). Currently, PEMs typically used for PEMFCs are mainly the commercially available Nafion^ membranes, which is high cost and loss of proton conductivity at elevated temperature. In this work, the Sulfonated poly(ether ketone ether sulfone), (S-PEKES), was synthesized by the nucleophilic aromatic substitution polycondensation between bisphenol S and 4,4'-dichlorobenzophenone, and followed by the sulfonation reaction with concentrated sulfuric acid. The molecular sieve was added in the S-PEKES matrix at various ratios to form composite membranes to be the candidate for PEM. Properties of both pure sulfonated polymer and composite membranes were compared with the commercial Nafion^ 117 membrane from Dupont. S-PEKES membranes cast from these materials were evaluated as a polymer electrolyte membrane for direct methanol fuel cells. The main properties investigated were the proton conductivity, methanol permeability, thermal, chemical, oxidative, and mechanical stabilities by using a LCR meter, Gas Chromatography, Thermogravimetric Analysis, Fourier Transform Infrared Spectroscopy, Fenton's reagent, and Universal Testing Machine. The addition of the molecular sieve helped to increase both the proton conductivity and the methanol stability. These composite membranes are shown as to be potential candidates for use as a Proton Exchange Membrane (PEM).

  11. UV-induced Self-initiated Graft Polymerization of Acrylamide onto Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    CHEN Rui-chao; SUN Hui; LI Ang; XU Guo-zhi

    2012-01-01

    Photo-grafting of hydrophilic monomer was used to enhance the hydrophilicity of poly(ether ether ketone)(PEEK) with the aim of extending its applications to biological fields.PEEK sheets were surface modified by grafting of acrylamide(AAm) with ultraviolet(UV) irradiation in the presence or absence of benzophenone(BP).The effects of BP,irradiation time and monomer concentration on the surface wettability of PEEK were investigated.Characterization of modified PEEK using scanning electron microscopy(SEM),energy-disperse spectrometer(EDS) and water contact angle measurements shows that AAm was successfully grafted on PEEK surface both in presence and absence of BP.With the increase in irradiation time and monomer concentration,contact angles decrease to as low as 30°,demonstrating a significant improvement of surface hydrophilicity.In agreement with the decrease in contact angle,under identical conditions,the nitrogen concentration increases,suggesting the increase in grafting degree of the grafting polymerization.This investigation demonstrates a self-initiation of PEEK due to its BP-like structure in the backbone of the polymer.Though the graft polymerization proceeds more readily in the presence of BP,the self-initiated graft polymerization is clearly observed.

  12. Probing the electronic structures and properties of neutral and charged monomethylated arsenic species (CH3As(n)((-1,0,+1)), n = 1-7) using Gaussian-3 theory.

    Science.gov (United States)

    Bai, Xue; Zhang, Qiancheng; Yang, Jucai; Ning, Hongmei

    2012-09-20

    The structures and energies of neutral and charged monomethylated arsenic species CH(3)As(n)((-1,0,+1)) (n = 1-7) have been systematically investigated with the Gaussian-3 (G3) method. The ground-state structures of monomethylated arsenic species including the neutrals and the ions are vertex-methylated type. The lowest-energy structures of neutral methylated arsenic species and their ions can be viewed as being derived from corresponding to neutral and ionic arsenic clusters, respectively. The reliable electron affinities and ionization potentials of CH(3)As(n) have been evaluated. And there are odd-even alternations in both electron affinities and ionization potentials as a function of size of CH(3)As(n). The dissociation energies of CH(3) from neutral CH(3)As(n) and their ions have been calculated to examine relative stabilities. The results characterized the odd-numbered neutral CH(3)As(n) as more stable than the even-numbered systems, and the even-numbered cationic CH(3)As(n)(+) as more stable than the odd-numbered species with the exception of n = 1. The dissociation energy of CH(3)As(+) is the maximum among all of these values. There are no odd-even alternations for anionic CH(3)As(n)(-) with n ≤ 7.

  13. EtherCAT bus application in CNC system%EtherCAT总线在数控系统中的应用

    Institute of Scientific and Technical Information of China (English)

    丁琳娜

    2012-01-01

    文章首先对应用EtherCAT的数控系统相关知识进行介绍,然后针对引入EtherCAT的数控系统的实现,提出了一种基于EtherCAT技术的实时通信及PC控制的可行系统方案,构建了EtherCAT主从站网络结构,并详细分析了EtherCAT主站与从站的软硬件设计.

  14. The Use of the Ames Test as a Tool for Addressing Problem-Based Learning in the Microbiology Lab

    Directory of Open Access Journals (Sweden)

    Eliana Rodríguez

    2012-08-01

    Full Text Available Our environment is full of potential carcinogens such as UV light, industrial pollutants, pesticides, and food additives, among others. It is estimated that 90% of all carcinogens are also mutagens. The Ames test is one of the most common tests for mutagens. In this problem-based learning activity, undergraduate biology students used the Ames test to screen a substance they provided, to see if it could be considered a mutagen. The idea of surveying substances used in everyday life appealed to our students, and helped engage them in this activity.

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

    Science.gov (United States)

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

    2001-01-01

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

  16. Updates on Modeling the Water Cycle with the NASA Ames Mars Global Climate Model

    Science.gov (United States)

    Kahre, M. A.; Haberle, R. M.; Hollingsworth, J. L.; Montmessin, F.; Brecht, A. S.; Urata, R.; Klassen, D. R.; Wolff, M. J.

    2017-01-01

    Global Circulation Models (GCMs) have made steady progress in simulating the current Mars water cycle. It is now widely recognized that clouds are a critical component that can significantly affect the nature of the simulated water cycle. Two processes in particular are key to implementing clouds in a GCM: the microphysical processes of formation and dissipation, and their radiative effects on heating/ cooling rates. Together, these processes alter the thermal structure, change the dynamics, and regulate inter-hemispheric transport. We have made considerable progress representing these processes in the NASA Ames GCM, particularly in the presence of radiatively active water ice clouds. We present the current state of our group's water cycle modeling efforts, show results from selected simulations, highlight some of the issues, and discuss avenues for further investigation.­

  17. Development of a new laser Doppler velocimeter for the Ames High Reynolds Channel No. II

    Science.gov (United States)

    Seegmiller, H. L.; Bader, J. B.; Cooney, J. P.; De Young, A.; Donaldson, R. W., Jr.

    1985-01-01

    A new two-channel laser Doppler velocimeter developed for the Ames High Reynolds Channel No. 2 is described. Design features required for the satisfactory operation of the optical system in the channel environment are discussed. Fiber optics are used to transmit the megahertz Doppler signal to the photodetectors located outside the channel pressure vessel, and provision is made to isolate the optical system from pressure and thermal strain effects. Computer-controlled scanning mirrors are used to position the laser beams in the channel flow. Techniques used to seed the flow with 0.5-micron-diam polystyrene spheres avoiding deposition on the test-section windows and porous boundary-layer removal panels are described. Preliminary results are presented with a discussion of several of the factors affecting accuracy.

  18. Development of a new laser Doppler velocimeter for the Ames High Reynolds Channel No. 2

    Science.gov (United States)

    Seegmiller, H. L.; Bader, J. B.; Cooney, J. P.; Deyoung, A.; Donaldson, R. W., Jr.; Gunter, W. D., Jr.; Harrison, D. R.

    1985-01-01

    A new two-channel laser Doppler velocimeter developed for the Ames High Reynolds Channel No. 2 is described. Design features required for the satisfactory operation of the optical system in the channel environment are discussed. Fiber optics are used to transmit the megahertz Doppler signal to the photodetectors located outside the channel pressure vessel, and provision is made to isolate the optical system from pressure and thermal strain effects. Computer-controlled scanning mirrors are used to position the laser beams in the channel flow. Techniques used to seed the flow with 0.5-micron-diam polystyrene spheres avoiding deposition on the test-section windows and porous boundary-layer removal panels are described. Preliminary results are presented with a discussion of several of the factors affecting accuracy.

  19. Comparative metabolism and mutagenicity of azo and hydrazone dyes in the Ames test.

    Science.gov (United States)

    De France, B F; Carter, M H; Josephy, P D

    1986-02-01

    Enteric bacterial and hepatic azoreductase enzymes are capable of reducing azo dyes to yield the constituent aromatic amines. Azo dyes based on benzidine and benzidine congeners have received particular attention because of their widespread use and the known carcinogenicity of benzidine to humans. Azo dyes based on beta-diketone coupling components exist preferentially as the tautomeric hydrazones. A series of hydrazone dyes based on benzidine and benzidine congeners was prepared and characterized by NMR and UV-visible spectroscopy. These dyes were tested for mutagenicity using a modified Ames assay and, unlike the true azo dyes, showed no significant mutagenic activity. The hydrazone dyes were resistant to enzymatic reduction by FMN-supplemented hamster-liver post-mitochondrial supernatant (S-9); under identical conditions, azo dyes such as trypan blue were rapidly reduced.

  20. Development of Implicit Methods in CFD NASA Ames Research Center 1970's - 1980's

    Science.gov (United States)

    Pulliam, Thomas H.

    2010-01-01

    The focus here is on the early development (mid 1970's-1980's) at NASA Ames Research Center of implicit methods in Computational Fluid Dynamics (CFD). A class of implicit finite difference schemes of the Beam and Warming approximate factorization type will be addressed. The emphasis will be on the Euler equations. A review of material pertinent to the solution of the Euler equations within the framework of implicit methods will be presented. The eigensystem of the equations will be used extensively in developing a framework for various methods applied to the Euler equations. The development and analysis of various aspects of this class of schemes will be given along with the motivations behind many of the choices. Various acceleration and efficiency modifications such as matrix reduction, diagonalization and flux split schemes will be presented.

  1. New Diagnostic, Launch and Model Control Techniques in the NASA Ames HFFAF Ballistic Range

    Science.gov (United States)

    Bogdanoff, David W.

    2012-01-01

    This report presents new diagnostic, launch and model control techniques used in the NASA Ames HFFAF ballistic range. High speed movies were used to view the sabot separation process and the passage of the model through the model splap paper. Cavities in the rear of the sabot, to catch the muzzle blast of the gun, were used to control sabot finger separation angles and distances. Inserts were installed in the powder chamber to greatly reduce the ullage volume (empty space) in the chamber. This resulted in much more complete and repeatable combustion of the powder and hence, in much more repeatable muzzle velocities. Sheets of paper or cardstock, impacting one half of the model, were used to control the amplitudes of the model pitch oscillations.

  2. New Quantitative Structure-Activity Relationship Models Improve Predictability of Ames Mutagenicity for Aromatic Azo Compounds.

    Science.gov (United States)

    Manganelli, Serena; Benfenati, Emilio; Manganaro, Alberto; Kulkarni, Sunil; Barton-Maclaren, Tara S; Honma, Masamitsu

    2016-10-01

    Existing Quantitative Structure-Activity Relationship (QSAR) models have limited predictive capabilities for aromatic azo compounds. In this study, 2 new models were built to predict Ames mutagenicity of this class of compounds. The first one made use of descriptors based on simplified molecular input-line entry system (SMILES), calculated with the CORAL software. The second model was based on the k-nearest neighbors algorithm. The statistical quality of the predictions from single models was satisfactory. The performance further improved when the predictions from these models were combined. The prediction results from other QSAR models for mutagenicity were also evaluated. Most of the existing models were found to be good at finding toxic compounds but resulted in many false positive predictions. The 2 new models specific for this class of compounds avoid this problem thanks to a larger set of related compounds as training set and improved algorithms.

  3. Development and Flight of the NASA-Ames Research Center Payload on Spacelab-J

    Science.gov (United States)

    Schmidt, Gregory K.; Ball, Sally M.; Stolarik, Thomas M.; Eodice, Michael T.

    1993-01-01

    Spacelab-J was an international Spacelab mission with numerous innovative Japanese and American materials and life science experiments. Two of the Spacelab-J experiments were designed over a period of more than a decade by a team from NASA-Ames Research Center. The Frog Embryology Experiment investigated and is helping to resolve a century-long quandary on the effects of gravity on amphibian development. The Autogenic Feedback Training Experiment, flown on Spacelab-J as part of a multi-mission investigation, studied the effects of Autogenic Feedback Therapy on limiting the effects of Space Motion Sickness on astronauts. Both experiments employed the use of a wide variety of specially designed hardware to achieve the experiment objectives. This paper reviews the development of both experiments, from the initial announcement of opportunity in 1978, through selection on Spacelab-J and subsequent hardware and science procedures development, culminating in the highly successful Spacelab-J flight in September 1992.

  4. Crystal structures of bis[2-(diphenylphosphinothioylphenyl] ether and bis{2-[diphenyl(selanylidenephosphanyl]phenyl} ether

    Directory of Open Access Journals (Sweden)

    Daron E. Janzen

    2014-12-01

    Full Text Available The title compounds, C36H28OP2S2, (1, and C36H28OP2Se2, (2, exhibit remarkably similar structures although they are not isomorphous. The whole molecule of compound (2 is generated by twofold symmetry, with the ether O atom located on the twofold axis. Both compounds have intramolecular π–π interactions between terminal phenyl rings with centroid–centroid distances of 3.6214 (16 and 3.8027 (14 Å in (1 and (2, respectively. In the crystal of (1, short C—H...S hydrogen bonds link the molecules, forming chains along [001], while in (2 there are no analogous C—H...Se interactions present.

  5. The Ames dwarf mutation attenuates Alzheimer's disease phenotype of APP/PS1 mice.

    Science.gov (United States)

    Puig, Kendra L; Kulas, Joshua A; Franklin, Whitney; Rakoczy, Sharlene G; Taglialatela, Giulio; Brown-Borg, Holly M; Combs, Colin K

    2016-04-01

    APP/PS1 double transgenic mice expressing human mutant amyloid precursor protein (APP) and presenilin-1 (PS1) demonstrate robust brain amyloid beta (Aβ) peptide containing plaque deposition, increased markers of oxidative stress, behavioral dysfunction, and proinflammatory gliosis. On the other hand, lack of growth hormone, prolactin, and thyroid-stimulating hormone due to a recessive mutation in the Prop 1 gene (Prop1df) in Ames dwarf mice results in a phenotype characterized by potentiated antioxidant mechanisms, improved learning and memory, and significantly increased longevity in homozygous mice. Based on this, we hypothesized that a similar hormone deficiency might attenuate disease changes in the brains of APP/PS1 mice. To test this idea, APP/PS1 mice were crossed to the Ames dwarf mouse line. APP/PS1, wild-type, df/+, df/df, df/+/APP/PS1, and df/df/APP/PS1 mice were compared at 6 months of age through behavioral testing and assessing amyloid burden, reactive gliosis, and brain cytokine levels. df/df mice demonstrated lower brain growth hormone and insulin-like growth factor 1 concentrations. This correlated with decreased astrogliosis and microgliosis in the df/df/APP/PS1 mice and, surprisingly, reduced Aβ plaque deposition and Aβ 1-40 and Aβ 1-42 concentrations. The df/df/APP/PS1 mice also demonstrated significantly elevated brain levels of multiple cytokines in spite of the attenuated gliosis. These data indicate that the df/df/APP/PS1 line is a unique resource in which to study aging and resistance to disease and suggest that the affected pituitary hormones may have a role in regulating disease progression.

  6. Alveolar macrophages infected with Ames or Sterne strain of Bacillus anthracis elicit differential molecular expression patterns.

    Directory of Open Access Journals (Sweden)

    Felicia D Langel

    Full Text Available Alveolar macrophages (AMs phagocytose Bacillus anthracis following inhalation and induce the production of pro-inflammatory cytokines and chemokines to mediate the activation of innate immunity. Ames, the virulent strain of B. anthracis, contains two plasmids that encode the antiphagocytic poly-γ-d-glutamic acid capsule and the lethal toxin. The attenuated Sterne strain of B. anthracis, which lacks the plasmid encoding capsule, is widely adapted as a vaccine strain. Although differences in the outcome of infection with the two strains may have originated from the presence or absence of an anti-phagocytic capsule, the disease pathogenesis following infection will be manifested via the host responses, which is not well understood. To gain understanding of the host responses at cellular level, a microarray analysis was performed using primary rhesus macaque AMs infected with either Ames or Sterne spores. Notably, 528 human orthologs were identified to be differentially expressed in AMs infected with either strain of the B. anthracis. Meta-analyses revealed genes differentially expressed in response to B. anthracis infection were also induced upon infections with multiple pathogens such as Francisella Novicida or Staphylococcus aureus. This suggests the existence of a common molecular signature in response to pathogen infections. Importantly, the microarray and protein expression data for certain cytokines, chemokines and host factors provide further insights on how cellular processes such as innate immune sensing pathways, anti-apoptosis versus apoptosis may be differentially modulated in response to the virulent or vaccine strain of B. anthracis. The reported differences may account for the marked difference in pathogenicity between these two strains.

  7. Mutagenicity of the cysteine S-conjugate sulfoxides of trichloroethylene and tetrachloroethylene in the Ames test.

    Science.gov (United States)

    Irving, Roy M; Elfarra, Adnan A

    2013-04-01

    The nephrotoxicity and nephrocarcinogenicity of trichloroethylene (TCE) and tetrachloroethylene (PCE) are believed to be mediated primarily through the cysteine S-conjugate β-lyase-dependent bioactivation of the corresponding cysteine S-conjugate metabolites S-(1,2-dichlorovinyl)-l-cysteine (DCVC) and S-(1,2,2-trichlorovinyl)-l-cysteine (TCVC), respectively. DCVC and TCVC have previously been demonstrated to be mutagenic by the Ames Salmonella mutagenicity assay, and reduction in mutagenicity was observed upon treatment with the β-lyase inhibitor aminooxyacetic acid (AOAA). Because DCVC and TCVC can also be bioactivated through sulfoxidation to yield the potent nephrotoxicants S-(1,2-dichlorovinyl)-l-cysteine sulfoxide (DCVCS) and S-(1,2,2-trichlorovinyl)-l-cysteine sulfoxide (TCVCS), respectively, the mutagenic potential of these two sulfoxides was investigated using the Ames Salmonella typhimurium TA100 mutagenicity assay. The results show both DCVCS and TCVCS were mutagenic, and TCVCS exhibited 3-fold higher mutagenicity than DCVCS. However, DCVCS and TCVCS mutagenic activity was approximately 700-fold and 30-fold lower than DCVC and TCVC, respectively. DCVC and DCVCS appeared to induce toxicity in TA100, as evidenced by increased microcolony formation and decreased mutant frequency above threshold concentrations. TCVC and TCVCS were not toxic in TA100. The toxic effects of DCVC limited the sensitivity of TA100 to DCVC mutagenic effects and rendered it difficult to investigate the effects of AOAA on DCVC mutagenic activity. Collectively, these results suggest that DCVCS and TCVCS exerted a definite but weak mutagenicity in the TA100 strain. Therefore, despite their potent nephrotoxicity, DCVCS and TCVCS are not likely to play a major role in DCVC or TCVC mutagenicity in this strain.

  8. Uji Mutagenik Ames untuk Melengkapi Data Keamanan Ekstrak Gambir (Uncaria gambir Roxb.

    Directory of Open Access Journals (Sweden)

    Novi Sulistyaningrum

    2015-05-01

    Full Text Available The main compound of Uncaria gambir Roxb. (gambir, catechin and it’s derivates have been believed to be potential as antiviral. Epigallocatechin gallate (EGCG and epicatechin are catechin derivates which are found to be potential as antiviral against Human Immunodeficiency Virus (HIV. However, gambir extract also contains quercetin that has possibility to be mutagenic. Therefore, a preliminary study towards safety of those compounds within gambir extract, mutagenicity assay using Ames Method has been performed.Sample (gambir extract was obtained from West Sumatera, Indonesia. The extract was characterized according to Farmakope Herbal Indonesia and WHO methods. Mutagenicity test by Ames method utilized a colorimetric microplate in 6 various concentration (125 mg/mL; 62.5 mg/mL; 31.25 mg/mL; 15.625 mg/mL; 7.81 mg/mL dan 3.91 mg/mL against mutant bacteria Salmonella typhimurium TA 98, Salmonella typhimurium TA 100 and Escherichia coli WP2 uvrA with and without the addition of S-9 enzyme. Extract of gambir in this study contains 86.60% of catechin, 12.92% moisture content, 22.49% water-soluble extract content, 80.63% ethanol-soluble extract content, 0.81% total ash, 0.32% acid insoluble ash content and 10.38% in dryness level. From the mutagenicity test and calculation, fold increase (over baseline of the sample in 6 various concentration with and without adding S-9 enzyme are lower than 2. Gambir extract from West Sumatra with catechin contains 86.6% hasn’t showed mutagenic effect due to the fold increase (over baseline of mutagenicity test lower than 2.

  9. The NASA Ames Research Center Institutional Scientific Collection: History, Best Practices and Scientific Opportunities

    Science.gov (United States)

    Rask, Jon C.; Chakravarty, Kaushik; French, Alison; Choi, Sungshin; Stewart, Helen

    2017-01-01

    The NASA Ames Life Sciences Institutional Scientific Collection (ISC), which is composed of the Ames Life Sciences Data Archive (ALSDA) and the Biospecimen Storage Facility (BSF), is managed by the Space Biosciences Division and has been operational since 1993. The ALSDA is responsible for archiving information and animal biospecimens collected from life science spaceflight experiments and matching ground control experiments. Both fixed and frozen spaceflight and ground tissues are stored in the BSF within the ISC. The ALSDA also manages a Biospecimen Sharing Program, performs curation and long-term storage operations, and makes biospecimens available to the scientific community for research purposes via the Life Science Data Archive public website (https:lsda.jsc.nasa.gov). As part of our best practices, a viability testing plan has been developed for the ISC, which will assess the quality of archived samples. We expect that results from the viability testing will catalyze sample use, enable broader science community interest, and improve operational efficiency of the ISC. The current viability test plan focuses on generating disposition recommendations and is based on using ribonucleic acid (RNA) integrity number (RIN) scores as a criteria for measurement of biospecimen viablity for downstream functional analysis. The plan includes (1) sorting and identification of candidate samples, (2) conducting a statiscally-based power analysis to generate representaive cohorts from the population of stored biospecimens, (3) completion of RIN analysis on select samples, and (4) development of disposition recommendations based on the RIN scores. Results of this work will also support NASA open science initiatives and guides development of the NASA Scientific Collections Directive (a policy on best practices for curation of biological collections). Our RIN-based methodology for characterizing the quality of tissues stored in the ISC since the 1980s also creates unique

  10. Stress shielding and fatigue limits of poly-ether-ether-ketone dental implants.

    Science.gov (United States)

    Lee, Woo-Taek; Koak, Jai-Young; Lim, Young-Jun; Kim, Seong-Kyun; Kwon, Ho-Beom; Kim, Myung-Joo

    2012-05-01

    The poly-ether-ether-ketone (PEEK) polymer is of great interest as an alternative to titanium in orthopedics because of its biocompatibility and low elastic modulus. This study evaluated the fatigue limits of PEEK and the effects of the low elastic modulus PEEK in relation to existing dental implants. Compressive loading tests were performed with glass fiber-reinforced PEEK (GFR-PEEK), carbon fiber-reinforced PEEK (CFR-PEEK), and titanium rods. Among these tests, GFR-PEEK fatigue tests were performed according to ISO 14801. For the finite element analysis, three-dimensional models of dental implants and bone were constructed. The implants in the test groups were coated with a 0.5-mm thick and 5-mm long PEEK layer on the upper intrabony area. The strain energy densities (SED) were calculated, and the bone resorption was predicted. The fatigue limits of GFR-PEEK were 310 N and were higher than the static compressive strength of GFR-PEEK. The bone around PEEK-coated implants showed higher levels of SED than the bone in direct contact with the implants, and the wider diameter and stiffer implants showed lower levels of SED. The compressive strength of the GFR-PEEK and CFR-PEEK implants ranged within the bite force of the anterior and posterior dentitions, respectively, and the PEEK implants showed adequate fatigue limits for replacing the anterior teeth. Dental implants with PEEK coatings and PEEK implants may reduce stress shielding effects. Dental implant application of PEEK polymer-fatigue limit and stress shielding. Copyright © 2012 Wiley Periodicals, Inc.

  11. Influence of Cellulose Ethers on Hydration Products of Portland Cement

    Institute of Scientific and Technical Information of China (English)

    MA Baoguo; OU Zhihua; JIAN Shouwei; XU Rulin

    2011-01-01

    Cellulose ethers are widely used to mortar formulations, and it is significant to understand the interaction between cellulose ethers and cement pastes. FT-IR spectra, thermal analysis and SEM are used to investigate hydration products in the cement pastes modified by HEMC and HPMC in this article. The results show that the hydration products in modified cement pastes were finally identical with those in the unmodified cement paste, but the major hydration products, such as CH (calcium hydroxide), ettringite and C-S-H, appeared later in the modified cement pastes than in the unmodified cement paste. The cellulose ethers decrease the outer products and increase inner products of C-S-H gels. Compared to unmodified cement pastes, no new products are found in the modified cement pastes in the present experiment. The HEMC and HPMC investigation shows almost the same influence on the hydration products of Portland cement.

  12. Synthesis and characterization of novel cellulose ether sulfates.

    Science.gov (United States)

    Rohowsky, Juta; Heise, Katja; Fischer, Steffen; Hettrich, Kay

    2016-05-20

    The synthesis and characterization of novel cellulose sulfate derivatives was reported. Various cellulose ethers were prepared in a homogeneous reaction with common sulfating agents. The received product possess different properties in dependence on the reaction conditions like sulfating agent, solvent, reaction time and reaction temperature. The cellulose ether sulfates are all soluble in water, they rheological behavior could be determined by viscosity measurements and the determination of the sulfur content by elemental analysis lead to a resulting degree of substitution ascribed to sulfate groups (DSSul) of the product. A wide range of products from DSSul 0.1 to DSSul 2.7 will be obtained. Furthermore the cellulose sulfate ethers could be characterized by Raman spectroscopy.

  13. Spontaneous Generation of Chirality in Simple Diaryl Ethers.

    Science.gov (United States)

    Lennartson, Anders; Hedström, Anna; Håkansson, Mikael

    2015-07-01

    We studied the spontaneous formation of chiral crystals of four diaryl ethers, 3-phenoxybenzaldehyde, 1; 1,3-dimethyl-2-phenoxybenzene, 2; di(4-aminophenyl) ether, 3; and di(p-tolyl) ether, 4. Compounds 1, 3, and 4 form conformationally chiral molecules in the solid state, while the chirality of 2 arises from the formation of supramolecular helices. Compound 1 is a liquid at ambient temperature, but 2-4 are crystalline, and solid-state CD-spectroscopy showed that they could be obtained as optically active bulk samples. It should be noted that the optical activity arise upon crystallization, and no optically active precursors were used. Indeed, even commercial samples of 3 and 4 were found to be optically active, giving evidence for the ease at which total spontaneous resolution may occur in certain systems.

  14. Highly efficient palladium-catalyzed hydrostannation of ethyl ethynyl ether.

    Science.gov (United States)

    Andrews, Ian P; Kwon, Ohyun

    2008-12-08

    The palladium-catalyzed hydrostannation of acetylenes is widely exploited in organic synthesis as a means of forming vinyl stannanes for use in palladium-catalyzed cross-coupling reactions. Application of this methodology to ethyl ethynyl ether results in an enol ether that is challenging to isolate from the crude reaction mixture because of incompatibility with typical silica gel chromatography. Reported here is a highly efficient procedure for the palladium-catalyzed hydrostannation of ethyl ethynyl ether using 0.1% palladium(0) catalyst and 1.0 equiv of tributyltin hydride. The product obtained is a mixture of regioisomers that can be carried forward with exclusive reaction of the beta-isomer. This method is highly reproducible; relative to previously reported procedures, it is more economical and involves a more facile purification procedure.

  15. 76 FR 36349 - Diethylene Glycol MonoEthyl Ether (DEGEE); Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2011-06-22

    ... study. Several mutagenicity studies (Ames test, micronucleus assay and unscheduled DNA synthesis) with DEGEE were available for review. One Ames test reported ambiguous results, another reported positive results at high doses. However, in vivo assays (micronucleus and unscheduled DNA synthesis)...

  16. The effect of calorie restriction on insulin signaling in skeletal muscle and adipose tissue of Ames dwarf mice.

    Science.gov (United States)

    Wiesenborn, Denise S; Menon, Vinal; Zhi, Xu; Do, Andrew; Gesing, Adam; Wang, Zhihui; Bartke, Andrzej; Altomare, Deborah A; Masternak, Michal M

    2014-10-01

    Long-living Ames dwarf (df/df) mice are homozygous for a mutation of the Prop1(df) gene. As a result, mice are deficient in growth hormone (GH), prolactin (PRL) and thyrotropin (TSH). In spite of the hormonal deficiencies, df/df mice live significantly longer and healthier lives compared to their wild type siblings. We studied the effects of calorie restriction (CR) on the expression of insulin signaling genes in skeletal muscle and adipose tissue of normal and df/df mice. The analysis of genes expression showed that CR differentially affects the insulin signaling pathway in these insulin target organs. Moreover, results obtained in both normal and Ames dwarf mice indicate more direct effects of CR on insulin signaling genes in adipose tissue than in skeletal muscle. Interestingly, CR reduced the protein levels of adiponectin in the epididymal adipose tissue of normal and Ames dwarf mice, while elevating adiponectin levels in skeletal muscle and plasma of normal mice only. In conclusion, our findings suggest that both skeletal muscle and adipose tissue are important mediators of insulin effects on longevity. Additionally, the results revealed divergent effects of CR on expression of genes in the insulin signaling pathway of normal and Ames dwarf mice.

  17. ASCORBIC ACID REDUCTION OF ACTIVE CHLORINE PRIOR TO DETERMINING AMES MUTAGENICITY OF CHLORINATED NATURAL ORGANIC MATTER (NOM)

    Science.gov (United States)

    Many potable water disinfection byproducts (DBPs) that result from the reaction of natural organic matter (NOM) with oxidizing chlorine are known or suspected to be carcinogenic and mutagenic. The Ames assay is routinely used to assess an overall level of mutagenicity for all com...

  18. Phenotypic Data Collection and Sample Preparation for Genomics of Wood Formation and Cellulosic Biomass Traits in Sunflower: Ames, IA location.

    Energy Technology Data Exchange (ETDEWEB)

    Marek, Laura F.

    2011-06-17

    Three fields were planted in Ames in 2010, two association mapping fields, N3 and A, and a recombinant inbred line field, N13. Phenotype data and images were transferred to UGA to support genetic and genomic analyses of woody biomass-related traits.

  19. EtherCAT被纳入EUROMAP协议规范

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    7月10日,欧洲的塑料和橡胶机械制造商协会批准在其应用中采用EtherCAT技术:EtherCAT被纳入EUROMAP75协议规范,成为其底层的通讯技术。在该协议规范的第三部分,描述有该实时以太网系统的实施。

  20. EtherCAT以太网现场总线

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    EtherCAT为现场总线系统树立了新的性能标准。它具备灵活的网络拓扑结构,系统配置简单,和现场总线系统一样操作直观简便。另外,由于EtherCAT实现成本低廉,因此使系统得以在过去无法应用现场总线网络的应用场合中选用现场总线。

  1. ELMO驱动器获得EtherCAT审批

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    ELMO公司宣布其Gold伺服驱动器已通过严格的EtherCAT一致性测试,使得ELMO成为仅有的通过测试的六家公司之一。ELMO投入了大量的时间、财力和技术来遵守行业协议,如EtherCAT协议,以及诸如Safety和EMC这样的标准。ELMO认为,遵守协议是强制性的,以确保任何工业设备的可靠运行。

  2. Enzymatic network for production of ether amines from alcohols

    DEFF Research Database (Denmark)

    Palacio, Cyntia M.; Crismaru, Ciprian G.; Bartsch, Sebastian

    2016-01-01

    of the desired ether amines from the corresponding ether alcohols with inorganic ammonium as the only additional substrate. To examine conversion, individual and overall reaction equilibria were established. Using these data, it was found that the experimentally observed conversions of up to 60% observed...... for reactions containing 10mM alcohol and up to 280mM ammonia corresponded well to predicted conversions. The results indicate that efficient amination can be driven by high concentrations of ammonia and may require improving enzyme robustness for scale-up....

  3. Synthesis and biophysical characterization of chlorambucil anticancer ether lipid prodrugs.

    Science.gov (United States)

    Pedersen, Palle J; Christensen, Mikkel S; Ruysschaert, Tristan; Linderoth, Lars; Andresen, Thomas L; Melander, Fredrik; Mouritsen, Ole G; Madsen, Robert; Clausen, Mads H

    2009-05-28

    The synthesis and biophysical characterization of four prodrug ether phospholipid conjugates are described. The lipids are prepared from the anticancer drug chlorambucil and have C16 and C18 ether chains with phosphatidylcholine or phosphatidylglycerol headgroups. All four prodrugs have the ability to form unilamellar liposomes (86-125 nm) and are hydrolyzed by phospholipase A(2), resulting in chlorambucil release. Liposomal formulations of prodrug lipids displayed cytotoxicity toward HT-29, MT-3, and ES-2 cancer cell lines in the presence of phospholipase A(2), with IC(50) values in the 8-36 microM range.

  4. Synthesis and Biophysical Characterization of Chlorambucil Anticancer Ether Lipid Prodrugs

    DEFF Research Database (Denmark)

    Pedersen, Palle Jacob; Christensen, Mikkel Stochkendahl; Ruysschaert, Tristan

    2009-01-01

    The synthesis and biophysical characterization of four prodrug ether phospholipid conjugates are described. The lipids are prepared from the anticancer drug chlorambucil and have C16 and C18 ether chains with phosphatidylcholine or phosphatidylglycerol headgroups. All four prodrugs have the ability...... to form unilamellar liposomes (86-125 nm) and are hydrolyzed by phospholipase A2, resulting in chlorambucil release. Liposomal formulations of prodrug lipids displayed cytotoxicity toward HT-29, MT-3, and ES-2 cancer cell lines in the presence of phospholipase A2, with IC50 values in the 8-36 μM range....

  5. Effects of dimethyl ether on n-butane oxidation

    OpenAIRE

    Bekat, Tuğçe; İnal, Fikret

    2014-01-01

    Dimethyl ether (DME) is the simplest ether and it is used as an alternative fuel or fuel additive to reduce toxic emissions from combustion processes. The effects of DME on n-butane oxidation were investigated for two different concentrations of DME in the fuel mixture (i.e., 20% and 50%) and two different fuel-rich equivalence ratios (i.e., 2.6 and 3.0) using detailed chemical kinetic modeling. Reactor model was selected as atmospheric-pressure, adiabatic, tubular reactor, operated under lam...

  6. Diphytanyl and dibiphytanyl glycerol ether lipids of methanogenic archaebacteria

    Energy Technology Data Exchange (ETDEWEB)

    Tornabene, T.G. (Colorado State Univ., Fort Collins); Langworthy, T.A.

    1979-01-05

    The lipids of nine different methanogenic bacterial strains are comprised of diphytanyl glycerol diethers, previously known only in extremely halophilic bacteria, as well as dibiphytanyl diglycerol tetraethers, known formerly only in the extremely thermoacidophilic bacteria Thermoplasma and Sulfolobus. Of the methanogens examined from four representative taxonomic groups, Methanobacterium and Methanospirillum contained both types of isopranyl ethers in nearly equal proportions, whereas the coccal forms, Methanosarcina and Methanococcus, possessed diphytanyl glycerol diethers, but with only a trace of or no dibiphytanyl diglycerol tetraethers. The occurrence of both types of isopranyl glycerol ethers in methanogenic bacteria supports the proposal that they have a close genealogical relationship to the extremely halophilic and thermoacidophilic bacteria.

  7. Environmental analysis of higher brominated diphenyl ethers and decabromodiphenyl ethane.

    Science.gov (United States)

    Kierkegaard, Amelie; Sellström, Ulla; McLachlan, Michael S

    2009-01-16

    Methods for environmental analysis of higher brominated diphenyl ethers (PBDEs), in particular decabromodiphenyl ether (BDE209), and the recently discovered environmental contaminant decabromodiphenyl ethane (deBDethane) are reviewed. The extensive literature on analysis of BDE209 has identified several critical issues, including contamination of the sample, degradation of the analyte during sample preparation and GC analysis, and the selection of appropriate detection methods and surrogate standards. The limited experience with the analysis of deBDethane suggests that there are many commonalities with BDE209. The experience garnered from the analysis of BDE209 over the last 15 years will greatly facilitate progress in the analysis of deBDethane.

  8. IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) ...

    Science.gov (United States)

    The IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) was released for external peer review in April 2017. EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) will conduct a peer review of the scientific basis supporting the ETBE assessment and release a final report of their review. Information regarding the peer review can be found on the SAB website. EPA is conducting an Integrated Risk Information System (IRIS) health assessment for Ethyl Tertiary Butyl Ether (ETBE). The outcome of this project is a Toxicological Review and IRIS Summary for ETBE that will be entered into the IRIS database.

  9. Acid Catalyzed Condensation of Phenylethanal Enol or Thiol Enol Ether to 2-Phenylnaphthalene

    Institute of Scientific and Technical Information of China (English)

    CHANG, Yu-An

    2007-01-01

    Treatment of enol ether or thiol enol ether of phenylethanals with sulfuric or polyphosphoric acid in toluene or xylene gave 2-phenylnaphthalene in good yield. More importantly, a one-pot reaction has been developed.

  10. Antimutagenic activity of major fractions of Zataria multiflora Boiss by Ames method

    Directory of Open Access Journals (Sweden)

    Fariba Sharififar

    2015-01-01

    Full Text Available Zataria multiflora is a medicinal plant that has been interested in antimutagenicity effect because of its high antioxidant activity and richness of flavonoids. Antimutagenicity effect of total extract of the plant has been reported previously. Aerial parts of Z. multiflora were extracted by petroleum ether, chloroform and 80% methanol by liquid-liquid extraction method consequently. The fractions were concentrated in vacuum and dried at 40°C in oven. The genotype of two standard strains of Salmonella typhimurium (TA98, TA100 was confirmed by the evaluation of two important factors of histidine requirement and the presence of R factor. The minimum inhibition concentration (MIC of the fractions against these two strains was determined by agar dilution method. From each fraction, various concentrations less than MIC were studied for anti-mutagenic test. The sample along with bacterial strain and mutagen agent were incubated at 37°C for 48 h. The number of revertant colonies was counted and compared with control plates. Our results showed that all fractions especially petroleum ether and chloroform ones maintain the number of colonies in the standard range in control plates and prevent from the growth of many strains of bacteria and increase of revertant colonies enhancement in a concentration-dependent manner. This effect was prominent against TA100 starin. Methanolic fraction exhibited anti-mutagen activity just in the highest used concentration in the presence of TA98.

  11. Aliphatic polycarbonates based on carbon dioxide, furfuryl glycidyl ether, and glycidyl methyl ether: reversible functionalization and cross-linking.

    Science.gov (United States)

    Hilf, Jeannette; Scharfenberg, Markus; Poon, Jeffrey; Moers, Christian; Frey, Holger

    2015-01-01

    Well-defined poly((furfuryl glycidyl ether)-co-(glycidyl methyl ether) carbonate) (P((FGE-co-GME)C)) copolymers with varying furfuryl glycidyl ether (FGE) content in the range of 26% to 100% are prepared directly from CO2 and the respective epoxides in a solvent-free synthesis. All materials are characterized by size-exclusion chromatography (SEC), (1)H NMR spectroscopy, and differential scanning calorimetry (DSC). The furfuryl-functional samples exhibit monomodal molecular weight distributions with Mw/Mn in the range of 1.16 to 1.43 and molecular weights (Mn) between 2300 and 4300 g mol(-1). Thermal properties reflect the amorphous structure of the polymers. Both post-functionalization and cross-linking are performed via Diels-Alder chemistry using maleimide derivatives, leading to reversible network formation. This transformation is shown to be thermally reversible at 110 °C.

  12. Two Reaction Mechanisms via Iminium Ion Intermediates: The Different Reactivities of Diphenylprolinol Silyl Ether and Trifluoromethyl-Substituted Diarylprolinol Silyl Ether.

    Science.gov (United States)

    Gotoh, Hiroaki; Uchimaru, Tadafumi; Hayashi, Yujiro

    2015-08-24

    The reactions of α,β-unsaturated aldehydes with cyclopentadiene in the presence of diarylprolinol silyl ethers as catalyst proceed via iminium cations as intermediates, and can be divided into two types; one involving a Michael-type reaction (type A) and one involving a cycloaddition (type B). Diphenylprolinol silyl ethers and trifluoromethyl-substituted diarylprolinol silyl ethers, which are widely used proline-type organocatalysts, have been investigated in this study. As the LUMO of the iminium ion derived from trifluoromethyl-substituted diarylprolinol silyl ether is lower in energy than that derived from diphenylprolinol silyl ether, as supported by ab initio calculations, the trifluoromethyl-substituted catalyst is more reactive in a type B reaction. The iminium ion from an α,β-unsaturated aldehyde is generated more quickly with diphenylprolinol silyl ether than with the trifluoromethyl-substituted diarylprolinol silyl ether. When the generation of the iminium ion is the rate-determining step, the diphenylprolinol silyl ether catalyst is the more reactive. Because acid accelerates the generation of iminium ions and reduces the generation of anionic nucleophiles in the Michael-type reaction (type A), it is necessary to select the appropriate acid for specific reactions. In general, diphenylprolinol silyl ether is a superior catalyst for type A reactions, whereas the trifluoromethyl-substituted diarylprolinol silyl ether catalyst is preferred for type B reactions.

  13. Growth Hormone Alters the Glutathione S-Transferase and Mitochondrial Thioredoxin Systems in Long-Living Ames Dwarf Mice

    Science.gov (United States)

    Rojanathammanee, Lalida; Rakoczy, Sharlene

    2014-01-01

    Ames dwarf mice are deficient in growth hormone (GH), prolactin, and thyroid-stimulating hormone and live significantly longer than their wild-type (WT) siblings. The lack of GH is associated with stress resistance and increased longevity. However, the mechanism underlying GH’s actions on cellular stress defense have yet to be elucidated. In this study, WT or Ames dwarf mice were treated with saline or GH (WT saline, Dwarf saline, and Dwarf GH) two times daily for 7 days. The body and liver weights of Ames dwarf mice were significantly increased after 7 days of GH administration. Mitochondrial protein levels of the glutathione S-transferase (GST) isozymes, K1 and M4 (GSTK1 and GSTM4), were significantly higher in dwarf mice (Dwarf saline) when compared with WT mice (WT saline). GH administration downregulated the expression of GSTK1 proteins in dwarf mice. We further investigated GST activity from liver lysates using different substrates. Substrate-specific GST activity (bromosulfophthalein, dichloronitrobenzene, and 4-hydrox-ynonenal) was significantly reduced in GH-treated dwarf mice. In addition, GH treatment attenuated the activity of thioredoxin and glutaredoxin in liver mitochondria of Ames mice. Importantly, GH treatment suppressed Trx2 and TrxR2 mRNA expression. These data indicate that GH has a role in stress resistance by altering the functional capacity of the GST system through the regulation of specific GST family members in long-living Ames dwarf mice. It also affects the regulation of thioredoxin and glutaredoxin, factors that regulate posttranslational modification of proteins and redox balance, thereby further influencing stress resistance. PMID:24285747

  14. Sulfoalkyl ether-alkyl ether cyclodextrin derivatives, their synthesis, NMR characterization, and binding of 6alpha-methylprednisolone.

    Science.gov (United States)

    Tongiani, Serena; Velde, David Vander; Ozeki, Tetsuya; Stella, Valentino J

    2005-11-01

    The objective of this study is to see if random alkyl ethers of various sulfoalkyl ether cyclodextrins can be synthesized and characterized. The purpose of the alkylation was to test the hypothesis that an increase in the "height" of a cyclodextrins cavity would help in the binding/complexation of larger more structurally complex molecules. The synthesis of new cyclodextrin derivatives comprising a mixture of sulfoalkyl ether and alkyl ether substituents on the same cyclodextrin ring was performed in aqueous alkaline solutions using various sultones and alkylsulfates. The method presented provided an easy and efficient way to modify cyclodextrins avoiding the use of organic solvents and high quantities of alkylating agents and could be carried out in either a two step or "one pot" single step process. Purification was by neutralization followed by ultrafiltration. The derivatives were characterized by 1D, ((1)H and (13)C), and a 2D NMR technique (HMQC, Heteronuclear Multiple Quantum Coherence). The combination of these techniques allowed an analysis of the degree of substitution and the site of substitution on the cyclodextrin (CD) nucleus. For both beta- and gamma-CD, sulfoakylation was preferred on the 2 > 3 > 6 hydroxyls while alkylation was preferred 6 > 2 > 3. Due to the simultaneous presence of short alkyl ether chains and negatively charged sulfoalkyl ether chains, these mixed water-soluble cyclodextrin derivatives, especially those of gamma-cyclodextrin, should be able to bind more complex drugs. The improved binding capacity of these new modified CDs with the model drug 6alpha-methylprednisolone is reported.

  15. Research of EtherCAT master based on Linux-RTAI%基于Linux-RTAI的EtherCAT主站研究

    Institute of Scientific and Technical Information of China (English)

    张少勋; 郗晓田

    2013-01-01

    工业以太网EtherCAT具有很好的实时性.为了进一步提高工业控制的实时性,本文创新性提出了基于Linux-RTAI的EtherCAT主站新架构;同时,详细阐述了其工作原理.最后在凌动D520工控机上进行测试,实验结果表明该架构具有极佳的实时性,非常适用于高实时控制场合.

  16. SULPHONATED POLY ETHER ETHER KETONE/POLYVINYL ALCOHOL/PHOSPHOTUNGSTIC ACID COMPOSITE MEMBRANES FOR PEM FUEL CELLS

    Institute of Scientific and Technical Information of China (English)

    S. Guhan; N.Arun Kumar; D.Sangeetha

    2009-01-01

    Composite membranes with polyvinyl alcohol (PVA),sulphonated poly ether ether ketone (SPEEK) and phosphotungstic acid (PWA) were prepared using solvent casting method.The proton conductivities of such membranes were found to be in the order of 10-3 S/cm in the fully hydrated condition at room temperature as measured by impedance spectroscopy.The crystalline properties were studied by X-ray diffraction analysis.The thermal properties were determined by TGA and DSC techniques.The tensile strength and percentage elongation were obtained from UTM studies.Water and methanol uptake of these membranes were studied.

  17. EtherCAT技术协会宣布成立中国代表处

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    在北京一年一度的自动化展会FA/PA2007的高峰论坛上。EtherCAT技术协会(EtherCAT Technology Group,ETG)主席Martin Rostan先生宣布了EtherCAT技术协会中国代表处的成立。

  18. 21 CFR 177.1970 - Vinyl chloride-lauryl vinyl ether copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl chloride-lauryl vinyl ether copolymers. 177... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1970 Vinyl chloride-lauryl vinyl ether copolymers. The vinyl chloride-lauryl vinyl ether copolymers identified in...

  19. Synthesis and Properties of New-type Troponoid Dithio-Crown Ethers

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Condensation of 3,7-dichloromethyl-5-isopropyl-2-methoxytropone 4 with bis (mer-captoethyl) ether 5a and mono, di, and tri-ethylene glycol bis(mercaptoethyl) ethers 5b-5d gave troponoid-annexed dithiocrown ethers 6a-6d. Compounds 6a-6d have selective and reversible mercury salt capturing ability.

  20. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs P...

  1. Specific detection of intramitochondrial superoxide produced by either cell activation or apoptosis by employing a newly developed cell-permeative lucigenin derivative, 10,10'-dimethyl-9,9'-biacridinium bis(monomethyl terephthalate).

    Science.gov (United States)

    Sasaki, Soichiro; Yamada, Sachiko; Iwamura, Michiko; Kobayashi, Yoshiro

    2013-12-01

    Here we developed a new cell-permeative lucigenin derivative, 10,10'-dimethyl-9,9'-biacridinium bis(monomethyl terephthalate) (MMT), to detect intracellular superoxide production. Both MMT and lucigenin were specific to superoxide among reactive oxygen species tested. Although lucigenin barely penetrated into cells, MMT accumulated in mitochondria in a variety of cells such as neutrophils. By employing MMT, we found that, upon activation of neutrophils with phorbol myristate acetate, superoxide was generated extracellularly as well as intramitochondrially and that such intramitochondrial superoxide production was dependent on oxidative phosphorylation. We also found that, during apoptosis, superoxide was gradually produced in mitochondria in association with phosphatidylserine exposure and that the kinetics of superoxide production was very heterogeneous at the single-cell level. Thus this study demonstrates that MMT could serve as a specific probe for intramitochondrial superoxide in either activated or apoptotic cells.

  2. Selection and identification of bacterial strains with methyl-tert-butyl ether, ethyl-tert-butyl ether, and tert-amyl methyl ether degrading capacities.

    Science.gov (United States)

    Purswani, Jessica; Pozo, Clementina; Rodríguez-Díaz, Marina; González-López, Jesús

    2008-11-01

    Nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/L of one of the following gasoline oxygenates: Methyl-tert-butyl ether (MTBE), ethyl-tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). These strains were identified by amplification of their 16S rRNA gene, using fDl and rD1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and cometabolic media. The isolates were classified as Bacillus simplex, Bacillus drentensis, Arthrobacter sp., Acinetobacter calcoaceticus, Acinetobacter sp., Gordonia amicalis (two strains), Nocardioides sp., and Rhodococcus ruber. Arthrobacter sp. (strain MG) and A. calcoaceticus (strain M10) consumed 100 (cometabolic medium) and 82 mg/L (mineral medium) of oxygenate TAME in 21 d, respectively, under aerobic conditions. Rhodococcus ruber (strain E10) was observed to use MTBE and ETBE as the sole carbon and energy source, whereas G. amicalis (strain T3) used TAME as the sole carbon and energy source for growth. All the bacterial strains transformed oxygenates better in the presence of an alternative carbon source (ethanol) with the exception of A. calcoaceticus (strain M10). The capacity of the selected strains to remove MTBE, ETBE, and TAME looks promising for application in bioremediation technologies.

  3. Dimethyl ether in diesel engines - progress and perspectives

    DEFF Research Database (Denmark)

    Sorenson, Spencer C

    2001-01-01

    A review of recent developments related to the use of dimethyl ether (DME) in engines is presented Research work discussed is in the areas of engine performance and emissions, fuel injection systems, spray and ignition delay, and detailed chemical kinetic modeling. DME's properties and safety...

  4. Ether lipids of planktonic archae in the marine water column

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Hoefs, M.J.L.; Schouten, S.; King, L.L.; Wakeham, S.G.; Leeuw, J.W. de

    1997-01-01

    Acyclic and cyclic biphytanes derived from the membrane ether lipids of archaea were found in water column particulate and sedimentary organic matter from several oxic and anoxic marine environments. Compound-specific isotope analyses of the carbon skeletons suggest that planktonic archaea utilize a

  5. The effect of gasses on the viscosity of dimethyl ether

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Jakobsen, Jørgen

    2008-01-01

    Dimethyl ether (DME) has been recognised as a clean substitute for diesel oil as it does not form soot during combustion. DME has a vapour pressure of 6 bar at 25 degrees C; so pressurisation is necessary to keep DME liquid at ambient temperature. Inert gases are good candidates as pressurising m...

  6. Conversion Excess Coal Gas to Dimethyl Ether in Steel Works

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the technical progress of metallurgical industry, more excess gas will be produced in steel works. The feasibility of producing dimethyl ether by gas synthesis was discussed, which focused on marketing, energy balance, process design, economic evaluation, and environmental protection etc. DME was considered to be a new way to utilize excess coal gas in steel works.

  7. Synthesis of hydroxytyrosyl alkyl ethers from olive oil waste waters

    OpenAIRE

    Juan Fernández-Bolaños; Mariana Trujillo; Guillermo Rodríguez; Raquel Mateos; Gema Pereira-Caro; Andrés Madrona; Espartero, José L.

    2009-01-01

    The preparation of a new type of derivatives of the naturally occurring antioxidant hydroxytyrosol is reported. Hydroxytyrosyl alkyl ethers were obtained in high yield by a three-step procedure starting from hydroxytyrosol isolated from olive oil waste waters. Preliminary results obtained by the Rancimat method have shown that these derivatives retain the high protective capacity of free hydroxytyrosol.

  8. Synthesis of Hydroxytyrosyl Alkyl Ethers from Olive Oil Waste Waters

    Directory of Open Access Journals (Sweden)

    Juan Fernández-Bolaños

    2009-05-01

    Full Text Available The preparation of a new type of derivatives of the naturally occurring antioxidant hydroxytyrosol is reported. Hydroxytyrosyl alkyl ethers were obtained in high yield by a three-step procedure starting from hydroxytyrosol isolated from olive oil waste waters. Preliminary results obtained by the Rancimat method have shown that these derivatives retain the high protective capacity of free hydroxytyrosol.

  9. Antiknock evaluation of hydrocarbons and ethers as aviation fuel components

    Science.gov (United States)

    Barnett, Henry C

    1950-01-01

    The results of a NACA investigation conducted over a period of several years to evaluate the anti-knock characteristics of organic compounds are summarized. Included are data for 18 branched paraffins and olefins, 27 aromatics, and 22 ethers. The factors of performance investigated were blending characteristics, temperature sensitivity, lead response, and relation between molecular structure and antiknock ratings. Four engines were used.

  10. Why do crown ethers activate enzymes in organic solvents?

    NARCIS (Netherlands)

    Unen, van Dirk-Jan; Engbersen, Johan F.J.; Reinhoudt, David N.

    2002-01-01

    One of the major drawbacks of enzymes in nonaqueous solvents is that their activity is often dramatically low compared to that in water. This limitation can be largely overcome by crown ether treatment of enzymes. In this paper, we describe a number of carefully designed new experiments that have im

  11. Anthracylmethyl Benzoazacrown Ether as Selective Fluorescence Sensors for Zn2+

    Institute of Scientific and Technical Information of China (English)

    Li Hua JIA; Xiang Feng GUO; Yuan Yuan LIU; Xu Hong QIAN

    2004-01-01

    A new benzoazacrown ether fluorescence sensor was synthesized with 9-anthrylmethyl chloride and benzoaza-15-crown-5 in CH3CN, which particularly shows a strong affinity for Zn2+. Its fluorescence quantum yield increase more than one order of magnitude and a red shift could be noticed when passing from the apolar to the polar solvent.

  12. Photodegradation of poly(ether sulphone). Part 2

    DEFF Research Database (Denmark)

    Norrman, K.; Krebs, Frederik C

    2004-01-01

    The photodegradation of poly(ether sulphone) (PES) was investigated systematically by time-of-flight SIMS (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS). The effect of varying the irradiation dose, wavelength and the atmosphere was studied along with mechanistic photooxidation studies using...

  13. Functionalization of thiocrown ethers containing the thioacetal unit

    NARCIS (Netherlands)

    Buter, Jan; Meijer, Renzo H.; Kellogg, Richard M.; Meijer, H.C.

    1998-01-01

    Thiocrown ethers containing thioacetal units are readily prepared by reaction of the cesium salts of long chain dithiols with methylene dibromide. Preparation of the trimethylsilyl derivatives followed by condensation with aldehydes under basic conditions (Peterson reaction) leads to the expected ma

  14. Isotope effects of hafnium in solvent extraction using crown ethers

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Toshiyuki; Moriyama, Hirotake [Research Reactor Institute, Kyoto University, Osaka (Japan); Hirata, Takafumi [Laboratory for Planetary Sciences, Tokyo Institute of Technology, Tokyo (Japan); Nishizawa, Kazushige [Department of Nuclear Engineering, Graduate School of Engineering, Osaka University, Osaka (Japan)

    2001-06-01

    Hafnium isotopes were fractionated in a liquid-liquid extraction system by using seven types of crown ethers, tributyl phosphate, or {omicron}-diethoxybenzene. The largest isotope effect was observed in the isotope pair of {sup 177}Hf-{sup 179}Hf with dibenzo-24-crown-8; the isotope enrichment factor was observed to be 0.0129{+-}0.0032. (author)

  15. Lithium air batteries having ether-based electrolytes

    Science.gov (United States)

    Amine, Khalil; Curtiss, Larry A.; Lu, Jun; Lau, Kah Chun; Zhang, Zhengcheng; Sun, Yang-Kook

    2016-10-25

    A lithium-air battery includes a cathode including a porous active carbon material, a separator, an anode including lithium, and an electrolyte including a lithium salt and polyalkylene glycol ether, where the porous active carbon material is free of a metal-based catalyst.

  16. Transforming BIM to BEM: Generation of Building Geometry for the NASA Ames Sustainability Base BIM

    Energy Technology Data Exchange (ETDEWEB)

    O' Donnell, James T. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Maile, Tobias [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rose, Cody [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mrazovic, Natasa [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Morrissey, Elmer [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Regnier, Cynthia [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Parrish, Kristen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Bazjanac, Vladimir [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2013-01-01

    Typical processes of whole Building Energy simulation Model (BEM) generation are subjective, labor intensive, time intensive and error prone. Essentially, these typical processes reproduce already existing data, i.e. building models already created by the architect. Accordingly, Lawrence Berkeley National Laboratory (LBNL) developed a semi-automated process that enables reproducible conversions of Building Information Model (BIM) representations of building geometry into a format required by building energy modeling (BEM) tools. This is a generic process that may be applied to all building energy modeling tools but to date has only been used for EnergyPlus. This report describes and demonstrates each stage in the semi-automated process for building geometry using the recently constructed NASA Ames Sustainability Base throughout. This example uses ArchiCAD (Graphisoft, 2012) as the originating CAD tool and EnergyPlus as the concluding whole building energy simulation tool. It is important to note that the process is also applicable for professionals that use other CAD tools such as Revit (“Revit Architecture,” 2012) and DProfiler (Beck Technology, 2012) and can be extended to provide geometry definitions for BEM tools other than EnergyPlus. Geometry Simplification Tool (GST) was used during the NASA Ames project and was the enabling software that facilitated semi-automated data transformations. GST has now been superseded by Space Boundary Tool (SBT-1) and will be referred to as SBT-1 throughout this report. The benefits of this semi-automated process are fourfold: 1) reduce the amount of time and cost required to develop a whole building energy simulation model, 2) enable rapid generation of design alternatives, 3) improve the accuracy of BEMs and 4) result in significantly better performing buildings with significantly lower energy consumption than those created using the traditional design process, especially if the simulation model was used as a predictive

  17. Study on the Multi-axis Motion Controller Based on EtherCAT%基于EtherCAT的多轴运动控制器研究

    Institute of Scientific and Technical Information of China (English)

    刘艳强; 王健; 单春荣

    2008-01-01

    研究了EtherCAT技术的原理、技术特点、性能以及EtherCAT主站和从站的实现方法.并在此基础上实现了一种基于EtherCAT的多轴运动控制器,用于数控设备和工业机器人的控制.

  18. EtherCAT-Industrial Ethernet Fieldbus and Its Driver Design%工业以太网现场总线EtherCAT及驱动程序设计

    Institute of Scientific and Technical Information of China (English)

    单春荣; 刘艳强; 郇极

    2007-01-01

    EtherCAT是一种新型的实时工业以太网现场总线.文章介绍了EtherCAT技术的原理、技术特点、性能以及EtherCAT主站和从站的配置方法、主站和从站驱动程序设计技术等.

  19. NETWORK CROWN ETHER POLYMERS WITH CENTRIC FUNCTIONAL GROUPS.Ⅱ.SYNTHESIS OF NETROWK CROWN ETHER POLYMER WITH PENDANT SULFIDE SIDE CHAIN AND ITS PLATINUM COMPLEX

    Institute of Scientific and Technical Information of China (English)

    CHENYuanyin; MENGLingzhi; 等

    1995-01-01

    Network crown ether polymer with pendant sulfide side chain in the network structure units has been synthesized via ring-opening copolymerization of β-ethylthioethyl glycidyl ether and diethylene glycol bisglycidyl ether.A kind of active catalyst suitable for this reaction was suggested.The title polymer was found to be a good ligand for platinous chloride,and the platinous complex could catalyze the hydrosilylation of ole fins with triethoxysilane efficiently.

  20. Ether CAT总线在数控系统中的应用

    Institute of Scientific and Technical Information of China (English)

    丁琳娜

    2012-01-01

    文章首先对应用EtherCAT的数控系统相关知识进行介绍,然后针对引入EtherCAT的数控系统的实现,提出了一种基于EtherCAT技术的实时通信及PC控制的可行系统方案,构建了EtherCAT主从站网络结构,并详细分析了EtherCAT主站与从站的软硬件设计。

  1. A mild and efficient procedure for the synthesis of ethers from various alkyl halides

    Directory of Open Access Journals (Sweden)

    Mosstafa Kazemi

    2013-10-01

    Full Text Available A simple, mild and practical procedure has been developed for the synthesis of symmetrical and unsymmetrical ethers by using DMSO, TBAI in the presence of K2CO3. We extended the utility of Potassium carbonate as an efficient base for the preparation of ethers. A wide range of alkyl aryl and dialkyl ethers are synthezied from treatment of aliphatic alcohols and phenols with various alkyl halides in the prescence of efficient base Potassium carbonate. Secondary alkyl halides were easily converted to corresponding ethers in releatively good yields . This is a mild, simple and practical procedure for the preparation of ethers in high yields and suitable times under mild condition.

  2. Modified nanocrystal cellulose/fluorene-containing sulfonated poly(ether ether ketone ketone) composites for proton exchange membranes

    Science.gov (United States)

    Wei, Yingcong; Shang, Yabei; Ni, Chuangjiang; Zhang, Hanyu; Li, Xiaobai; Liu, Baijun; Men, Yongfeng; Zhang, Mingyao; Hu, Wei

    2017-09-01

    Highly sulfonated poly(ether ether ketone ketone)s (SFPEEKKs) with sulfonation degrees of 2.34 (SFPEEKK5) and 2.48 (SFPEEKK10) were synthesized through the direct sulfonation of a fluorene-containing poly(ether ether ketone ketone) under a relatively mild reaction condition. Using the solution blending method, sulfonated nanocrystal cellulose (sNCC)-enhanced SFPEEKK composites (SFPEEKK/sNCC) were successfully prepared for investigation as proton exchange membranes. Transmission electron microscopy showed that sNCC was uniformly distributed in the composite membranes. The properties of the composite membranes, including thermal stability, mechanical properties, water uptake, swelling ratio, oxidative stability and proton conductivity were thoroughly evaluated. Results indicated that the insertion of sNCC could contribute to water management and improve the mechanical performance of the membranes. Notably, the proton conductivity of SFPEEKK5/sNCC-5 was as high as 0.242 S cm-1 at 80 °C. All data proved the potential of SFPEEKK/sNCC composites for proton exchange membranes in medium-temperature fuel cells.

  3. Comparative photophysical behaviour of naphthalene-linked crown ethers and aza crown ethers of varying cavity dimensions

    Indian Academy of Sciences (India)

    Subhodip Samanta; Pinki Saha Sardar; Shyam Sundar Maity; Anirban Pal; Maitrayee Basu Roy; Sanjib Ghosh

    2007-03-01

    A comparative time-resolved emission studies of several naphtho-crown ethers I-V, where metal ions can be complexed in a predetermined orientation with respect to the naphthalene (Naph) - plane and naphthalene-linked aza crown ethers (L1 and L2) have been presented. In both the systems, crown ethers and aza crown ethers, naphthalene fluorescence gets quenched. In the systems I to V, the quenching is mainly due to efficient spin-orbit coupling (SOC) leading to greater population of the lowest triplet state of naphthalene. This SOC depends on the orientation of the crown ring with respect to the Naph--plane. However, in the systems L1 and L2, the quenching is due to photoinduced electron transfer (PET) from nitrogen lone pair of the aza crown ring to naphthalene moiety and consequent exciplex formation. The results have been interpreted using the time-resolved emission studies of all the compounds in various solvents, their alkali metal ion complexes, and protonated ligands.

  4. Designed poly(ether-imide)s and fluoro-copoly(ether-imide)s: Synthesis, characterization and their film properties

    Energy Technology Data Exchange (ETDEWEB)

    Vora, Rohitkumar H. [Advanced Polymer Research and Technologies, 505 Cinder Road, Edison, NJ 08820 (United States)]. E-mail: rohitvora@apr-technologies.com; Goh, Suat Hong [Department of Chemistry, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore)

    2006-07-25

    Two series of amorphous fluoro-poly(ether-imide) (6F-PEI) and one series of fluoro-coploy(ether-imide) (6F-CoPEI) polymers based on 2,2'-bis(3,4-dicarboxyphenyl) hexafluropropane dianhydride (6FDA) and di-ether-containing diamines: 1,2'-bis(4-aminophenoxy)benzene (o-BAPOB) and 4,4'-bis(4-aminophenoxy)diphenyl sulfone (p-SED) were synthesized. The solution properties, chemical resistance, thermal stability, mechanical properties, thermo-oxidative and hydrolytic stability of selected 6F-PEIs and 6F-CoPEIs were studied. The dielectric constant ({epsilon}') values of 6F-PEI and 6F-CoPEI were estimated by additive group contribution calculation using mathematical equations defined by the Lorentz-Lorenz's theory and the Vogel's theory, and by Vora-Wang equations, respectively. These polymers not only showed excellent electrical properties but also excellent long-term thermo-oxidative stability and reduced water absorption relative to non-fluorinated polyimides. The estimated dielectric constant of these polymers ({epsilon}' < 3.15) were lower than those of commercially available poly(ether-imide) ULTEM[reg] 1000 and polyimides Kapton[reg] H, respectively at 1 kHz. The analytical results are summarized and discussed.

  5. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha, E-mail: sangeetha@annauniv.edu

    2014-03-01

    Graphical abstract: - Highlights: • Sulfonated poly ether ether ketone (SPEEK) membrane in SCMFC used to determine the BOD. • The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm. • This sensing range was 62.5% higher than that of Nafion{sup ®}. • SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}. • Nafion{sup ®} shows high anodic internal resistance (67 Ω) than the SPEEK (39 Ω). - Abstract: The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion{sup ®}. The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}, resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria.

  6. Use of fluorinated polybrominated diphenyl ethers and simplified cleanup for the analysis of polybrominated diphenyl ethers in house dust

    Science.gov (United States)

    A simple, cost-effective method is described for the analysis of polybrominated diphenyl ethers (PBDEs) in house dust using pressurized fluid extraction, cleanup with modified silica solid phase extraction tubes, and fluorinated internal standards. There are 14 PBDE congeners inc...

  7. Evaluation of genotoxicity of Trois through Ames and in vitro chromosomal aberration tests

    Institute of Scientific and Technical Information of China (English)

    Manu Chaudhary; Anurag Payasi

    2013-01-01

    Objective: To investigate the mutagenic potential of Trois using the bacterial reverse mutation assay (Ames test) and in vitro chromosomal aberration test.Methods:typhimurium (TA 98, TA100, TA1535 and TA1537) and Escherichia coli (WP2 uvrA) with and without metabolic activation system (S9 mix) at the dose range of 313 to 5000 µg/plate. Chromosomal aberrations were evaluated in Chinese hamster lung (CHL) cell line at the dose levels of 15, 7.5, 3.7, 1.9 and 0.9 mg/mL in the absence and presence of S9 mix.Results:The ability of Trois to induce reverse mutations was evaluated in Salmonella Trois used in the study with and without S9 mix in all tester strains. Trois did not produce any structural aberration in CHL cells in the presence or absence of S9 mix. There were no increases in the number of revertant colonies at any concentrations of Conclusions: Results of this study suggest that Trois is non-mutagenic.

  8. Passive dosing: an approach to control mutagen exposure in the Ames fluctuation test.

    Science.gov (United States)

    Bougeard, Cynthia; Gallampois, Christine; Brack, Werner

    2011-04-01

    One of the major challenges for mutagenicity assessment of environmental samples and individual compounds for example in the Ames fluctuation test (AFT) is the establishment and control of a well defined exposure concentration. Thus, a combination of passive dosing with silicone O-rings (SRs) together with an analytical confirmation of the freely dissolved concentration (FDC) is presented. FDCs are often determined with a combination of solid phase micro-extraction (SPME) with gas chromatography (GC). For compounds with poor performance in GC, a high performance liquid chromatography-mass spectrometry (HPLC-MS) analysis of bi-distilled water dosed with identically loaded SRs is suggested to avoid interference of the bacterial culture. The approach was tested for six amino-, nitro-, and keto-substituted polycyclic aromatic compounds with a logK(OW) range of 2.5-5.1 without metabolic activation. The method provided reliable concentration-effect relationships and freely dissolved 50% effect concentrations (DEC(50)) 3-33 times lower than nominal effect concentrations (NEC(50)) derived in parallel solvent-dosed AFT. Partition coefficients and NEC(50)/DEC(50) ratios were well correlated with lipophilicity.

  9. Emission Spectroscopy and Radiometric Measurements in the NASA Ames IHF Arc Jet Facility

    Science.gov (United States)

    Winter, Michael W.; Raiche, George A.; Prabhu, Dinesh K.

    2012-01-01

    Plasma diagnostic measurement campaigns in the NASA Ames Interaction Heating Facility (IHF) have been conducted over the last several years with a view towards characterizing the flow in the arc jet facility by providing data necessary for modeling and simulation. Optical emission spectroscopy has been used in the plenum and in the free jet of the nozzle. Radiation incident over a probe surface has also been measured using radiometry. Plenum measurements have shown distinct radial profiles of temperature over a range of operating conditions. For cases where large amounts of cold air are added radially to the main arc-heated stream, the temperature profiles are higher by as much as 1500 K than the profiles assumed in flow simulations. Optical measurements perpendicular to the flow direction in the free jet showed significant contributions to the molecule emission through inverse pre-dissociation, thus allowing determination of atom number densities from molecular emission. This has been preliminarily demonstrated with the N2 1st Positive System. Despite the use of older rate coefficients, the resulting atom densities are reasonable and surprisingly close to flow predictions.

  10. Scholarship, publication, and career advancement in health professions education: AMEE Guide No. 43.

    Science.gov (United States)

    McGaghie, William C

    2009-07-01

    Scholarship and publication are key contributors to career advancement in health professions education worldwide. Scholarship is expressed in many ways including original research; integration and synthesis of ideas and data, often across disciplines; application of skill and knowledge to problems that have consequences for health professionals, students, and patients; and teaching in many forms. Professional publication also has diverse outlets ranging from empirical articles in peer reviewed journals, textbook chapters, videos, simulation technologies, and many other means of expression. Scholarship and publication are evaluated and judged using criteria that are consensual, public, and transparent. This three-part AMEE Guide presents advice about how to prepare and publish health professions education research reports and other forms of scholarship in professional journals and other outlets. Part One addresses scholarship-its varieties, assessment, and attributes of productive scholars and scholarly teams. Part Two maps the road to publication, beginning with what's important and reportable and moving to manuscript planning and writing, gauging manuscript quality, manuscript submission and review, and writing in English. Part Three offers 21 practical suggestions about how to advance a successful and satisfying career in the academic health professions. Concluding remarks encourage health professions educators to pursue scholarship with vision and reflection.

  11. Incorporation of EGPWS in the NASA Ames Research Center 747-400 Flight Simulator

    Science.gov (United States)

    Sallant, Ghislain; DeGennaro, Robert A.

    2001-01-01

    The NASA Ames Research Center CAE Boeing 747300 flight simulator is used primarily for the study of human factors in aviation safety. The simulator is constantly upgraded to maintain a configuration match to a specific United Airlines aircraft and maintains the highest level of FAA certification to ensure credibility to the results of research programs. United's 747-400 fleet and hence the simulator are transitioning from the older Ground Proximity Warning System (GPWS) to the state-of-the-art Enhanced Ground Proximity Warning System (EGPWS). GPWS was an early attempt to reduce or eliminate Controlled Flight Into Terrain (CFIT). Basic GPWS alerting modes include: excessive descent rate, excessive terrain closure rate, altitude loss after takeoff, unsafe terrain clearance, excessive deviation below glideslope, advisory callouts and windshear alerting. However, since GPWS uses the radar altimeter which looks straight down, ample warning is not always provided. EGPWS retains all of the basic functions of GPWS but adds the ability to look ahead by comparing the aircraft position to an internal database and provide additional alerting and display capabilities. This paper evaluates three methods of incorporating EGPWS in the simulator and describes the implementation and architecture of the preferred option.

  12. Multifragmentation in Xe(50 AMeV) + Sn: Confrontation of theory and data

    CERN Document Server

    Nebauer, R; Assenard, M; Auger, G; Bacri, C O; Bocage, F; Bougault, R; Brou, R; Buchet, P; Charvet, J L; Chbihi, A; Colin, J; Cussol, D; Dayras, R; Demeyer, A N; Doré, D; Durand, D; Eudes, P; Galíchet, E; Genouin-Duhamel, E; Gerlic, E; Germain, M; Gourio, D; Guinet, D; Lautesse, P; Laville, J L; Lefort, T; Legrain, R; Le Neindre, N; López, O; Louvel, M; Maskay, A M; Nalpas, L; Nguyen, A D; Pârlog, M; Péter, J; Rahmani, A; Reposeur, T; Rosato, E; Saint-Laurent, F; Salou, S; Steckmeyer, J C; Stern, M; Tabacaru, G; Tamain, B; Tassan-Got, L; Tirel, O; Vient, E; Volant, C; Wieleczko, J P

    1999-01-01

    We compare in detail central collisions Xe(50 AMeV) +Sn, recently measured by the INDRA collaboration, with the Quantum Molecular Dynamics (QMD) model in order to identify the reaction mechanism which leads to multifragmentation. We find that QMD describes most of the data quite well, in the projectile/target region as well as in the midrapidity zone where also statistical models can be and have been employed. The agreement between QMD and data allows us to use this dynamical model to investigate the reaction in detail. We arrive at the following observations: (a) the in-medium nucleon-nucleon cross section is not significantly different from the free cross section, (b) even the central collisions have a binary character, (c) most of the fragments are produced in the central collisions, (d) the simulations as well as the data show a strong attractive in-plane flow resembling deep inelastic collisions, and (e) at midrapidity the results from QMD and those from statistical model calculations agree for almost al...

  13. Ames stereo pipeline-derived digital terrain models of Mercury from MESSENGER stereo imaging

    Science.gov (United States)

    Fassett, Caleb I.

    2016-12-01

    In this study, 96 digital terrain models (DTMs) of Mercury were created using the Ames Stereo Pipeline, using 1456 pairs of stereo images from the Mercury Dual Imaging System instrument on MESSENGER. Although these DTMs cover only 1% of the surface of Mercury, they enable three-dimensional characterization of landforms at horizontal resolutions of 50-250 m/pixel and vertical accuracy of tens of meters. This is valuable in regions where the more precise measurements from the Mercury Laser Altimeter (MLA) are sparse. MLA measurements nonetheless provide an important geodetic framework for the derived stereo products. These DTMs, which are publicly released in conjunction with this paper, reveal topography of features at relatively small scales, including craters, graben, hollows, pits, scarps, and wrinkle ridges. Measurements from these data indicate that: (1) hollows have a median depth of 32 m, in basic agreement with earlier shadow measurement, (2) some of the deep pits (up to 4 km deep) that are interpreted to form via volcanic processes on Mercury have surrounding rims or rises, but others do not, and (3) some pits have two or more distinct, low-lying interior minima that could represent multiple vents.

  14. Flow Property Measurement Using Laser-Induced Fluorescence in the NASA Ames Interaction Heating Facility

    Science.gov (United States)

    Grinstead, Jay Henderson; Porter, Barry J.; Carballo, Julio Enrique

    2011-01-01

    The spectroscopic diagnostic technique of two photon absorption laser-induced fluorescence (TALIF) of atomic species has been applied to single-point measurements of velocity and static temperature in the NASA Ames Interaction Heating Facility (IHF) arc jet. Excitation spectra of atomic oxygen and nitrogen were recorded while scanning a tunable dye laser over the absorption feature. Thirty excitation spectra were acquired during 8 arc jet runs at two facility operating conditions; the number of scans per run varied between 2 and 6. Curve fits to the spectra were analyzed to recover their Doppler shifts and widths, from which the flow velocities and static temperatures, respectively, were determined. An increase in the number of independent flow property pairs from each as-measured scan was obtained by extracting multiple lower-resolution scans. The larger population sample size enabled the mean property values and their uncertainties for each run to be characterized with greater confidence. The average plus or minus 2 sigma uncertainties in the mean velocities and temperatures for all 8 runs were plus or minus 1.4% and plus or minus 11%, respectively.

  15. Ames expedited site characterization demonstration at the former manufactured gas plant site, Marshalltown, Iowa

    Energy Technology Data Exchange (ETDEWEB)

    Bevolo, A.J.; Kjartanson, B.H.; Wonder, J.D.

    1996-03-01

    The goal of the Ames Expedited Site Characterization (ESC) project is to evaluate and promote both innovative technologies (IT) and state-of-the-practice technologies (SOPT) for site characterization and monitoring. In April and May 1994, the ESC project conducted site characterization, technology comparison, and stakeholder demonstration activities at a former manufactured gas plant (FMGP) owned by Iowa Electric Services (IES) Utilities, Inc., in Marshalltown, Iowa. Three areas of technology were fielded at the Marshalltown FMGP site: geophysical, analytical and data integration. The geophysical technologies are designed to assess the subsurface geological conditions so that the location, fate and transport of the target contaminants may be assessed and forecasted. The analytical technologies/methods are designed to detect and quantify the target contaminants. The data integration technology area consists of hardware and software systems designed to integrate all the site information compiled and collected into a conceptual site model on a daily basis at the site; this conceptual model then becomes the decision-support tool. Simultaneous fielding of different methods within each of the three areas of technology provided data for direct comparison of the technologies fielded, both SOPT and IT. This document reports the results of the site characterization, technology comparison, and ESC demonstration activities associated with the Marshalltown FMGP site. 124 figs., 27 tabs.

  16. Physical-Chemical Solid Waste Processing for Space Missions at Ames Research Center

    Science.gov (United States)

    Fisher, John W.; Pisharody, Suresh; Moran, Mark; Wignarajah, K.; Tleimat, Maher; Pace, Greg

    2001-01-01

    As space missions become longer in duration and reach out to more distant locations such as Mars, solids waste processing progresses from storage technologies to reclamation technologies. Current low Earth orbit technologies consist of store-and dispose to space or return to Earth. Fully regenerative technologies recycle wastes. The materials reclaimed from waste can be used to provide the basic materials to support plant growth for food including carbon dioxide, water, and nutrients. Other products can also be reclaimed from waste such as hydrocarbons and activated carbon. This poster describes development at Ames Research Center of a process to make activated carbon from space mission wastes and to make an incineration system that produces clean flue gas. Inedible biomass and feces contain hydrocarbons in a form that can be pyrolyzed and converted to activated carbon. The activated carbon can then be used to clean up contaminants from various other life support systems; in particular, the activated carbon can be used regeneratively to remove NOx from incinerator flue gas. Incinerator flue gas can also be cleaned up by the use of reductive and oxidative catalysts. A catalytic incinerator flue gas cleanup system has been developed at ARC that produces flue gas clean enough (with the exception of carbon dioxide) to meet the Space Minimum Allowable Concentration limits for human exposure.

  17. Low-level jets in the NASA Ames Mars general circulation model

    Science.gov (United States)

    Joshi, M. M.; Haberle, R. M.; Barnes, J. R.; Murphy, J. R.; Schaeffer, J.

    1997-03-01

    Previous simulations of the Martian atmosphere have shown how topography acts to confine the low-level Hadley cell flow into intense jets on the eastern flanks of Tharsis and Syrtis Major. We now conduct detailed studies of these jets using the NASA Ames Mars general circulation model (MGCM). The structure of the flow is found to be sensitive to local topography as well as large-scale diabatic heating patterns, consistent with terrestrial studies, and MGCM studies carried out with simplified topography. The summer subtropical zonal winds associated with the Hadley circulation also form spatially confined intense jet cores. Diurnal variations in heating affect jet structure in three distinct ways. Global tides interact with the jets, resulting in effects such as the two reinforcing each other at the summer subtropics near midday, leading to high winds and surface stresses at this time. Slope winds act to change the character of the jets during the course of a day, especially at Syrtis Major and the Hellas basin, where slopes are large. Vertical mixing acts to decrease low-level winds during the late afternoon. The sensitivity of the results to atmospheric dust loading is examined. We finally show how a decrease in boundary layer height due to dust loading actually augments mid-afternoon jet strength near the surface. The resulting increase in maximum surface stress indicates that this is a positive feedback to dust lifting.

  18. Training for life science experiments in space at the NASA Ames Research Center

    Science.gov (United States)

    Rodrigues, Annette T.; Maese, A. Christopher

    1993-01-01

    As this country prepares for exploration to other planets, the need to understand the affects of long duration exposure to microgravity is evident. The National Aeronautics and Space Administration (NASA) Ames Research Center's Space Life Sciences Payloads Office is responsible for a number of non-human life sciences payloads on NASA's Space Shuttle's Spacelab. Included in this responsibility is the training of those individuals who will be conducting the experiments during flight, the astronauts. Preparing a crew to conduct such experiments requires training protocols that build on simple tasks. Once a defined degree of performance proficiency is met for each task, these tasks are combined to increase the complexity of the activities. As tasks are combined into in-flight operations, they are subjected to time constraints and the crew enhances their skills through repetition. The science objectives must be completely understood by the crew and are critical to the overall training program. Completion of the in-flight activities is proof of success. Because the crew is exposed to the background of early research and plans for post-flight analyses, they have a vested interest in the flight activities. The salient features of this training approach is that it allows for flexibility in implementation, consideration of individual differences, and a greater ability to retain experiment information. This training approach offers another effective alternative training tool to existing methodologies.

  19. Biodegradability of fuel-ethers in environment; Biodegradabilite des ethers-carburants dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Fayolle-Guichard, F.

    2005-04-01

    Fuel ethers (methyl tert-butyl ether or MTBE, ethyl tert-butyl ether or ETBE and tert-amyl methyl ether or TAME have been used as gasoline additives since about twenty years in order to meet the requirements for the octane index and to limit the polluting emission in exhaust pipe gas (unburnt hydrocarbons and carbon monoxide). The high water solubility and the poor biodegradability of these compounds make them pollutants frequently encountered in aquifers. The present manuscript summarizes the knowledge concerning the biodegradability of fuel ethers obtained both at IFP and during collaborations with the Pasteur Institute (Paris), the Biotechnology Research Institute (Montreal, Canada) and the Center for Environmental Biotechnology (University of Tennessee, USA). Rhodococcus ruber IFP 2001 and Mycobacterium austroafricanum IFP 2012, two microorganisms isolated at IFP for their ability to grow, respectively, on ETBE and MTBE, were studied in order to determine the intermediates produced during MTBE and ETBE biodegradation and the enzymes required for each biodegradation step, thus allowing us to propose MTBE and ETBE catabolic pathways. A proteomic approach, from the protein induced during the degradation of ETBE or MTBE to the genes encoding these different enzymes, was carried out. The isolation of such genes is required:1) to use them for help in determining the bio-remediation capacities in polluted aquifers (DNA micro-arrays), 2) to monitor the microorganisms isolated for their degradative capacities during bio-remediation processes (fluorescent in situ hybridization or FISH) and 3) to create new tools for the detection and the quantification of ETBE or MTBE in contaminated aquifers (bio-sensor). The manuscript also describes the different ways for the adaptation of microorganisms to the presence of a xenobiotic compound. (author)

  20. Degradation of various alkyl ethers by alkyl ether-degrading Actinobacteria isolated from activated sludge of a mixed wastewater treatment.

    Science.gov (United States)

    Kim, Yong-Hak; Cha, Chang-Jun; Engesser, Karl-Heinrich; Kim, Sang-Jong

    2008-11-01

    Various substrate specificity groups of alkyl ether (AE)-degrading Actinobacteria coexisted in activated sewage sludge of a mixed wastewater treatment. There were substrate niche overlaps including diethyl ether between linear AE- and cyclic AE-degrading strains and phenetole between monoalkoxybenzene- and linear AE-degrading strains. Representatives of each group showed different substrate specificities and degradation pathways for the preferred substrates. Determining the rates of initial reactions and the initial metabolite(s) from whole cell biotransformation helped us to get information about the degradation pathways. Rhodococcus sp. strain DEE5311 and Rhodococcus rhodochrous strain 117 both were able to degrade anisole and phenetole through aromatic 2-monooxygenation to form 2-alkoxyphenols. In contrast, diethyl ether-oxidizing strain DEE5311 capable of degrading a broad range of linear AE, dibenzyl ether and monoalkoxybenzenes initially transformed anisole and phenetole to phenol via direct O-dealkylation. Compared to this, cyclic AE-degrading Rhodococcus sp. strain THF100 preferred tetrahydrofuran (265 ± 35 nmol min(-1)mg(-1) protein) to diethyl ether (diethoxybenzene-degrading Rhodococcus sp. strain DEOB100 and Gordonia sp. strain DEOB200 transformed 1,3-/1,4-dialkoxybenzenes to 3-/4-alkoxyphenols by similar manners in the order of rates (nmol min(-1) mg(-1) protein): 1,4-diethoxybenzene (11.1 vs. 3.9)>1,4-dimethoxybenzene (1.6 vs. 2.6)>1,3-dimethoxybenzene (0.6 vs. 0.6). This study suggests that the AE-degrading Actinobacteria can orchestrate various substrate specificity responses to the degradation of various categories of AE pollutants in activated sludge communities.

  1. Out-of-plane emission of nuclear matter in Au+Au collisions between 100 and 800 AMeV

    Energy Technology Data Exchange (ETDEWEB)

    Bastid, N.; Buta, A.; Crochet, P. [and others; FOPI Collaboration

    1996-12-31

    We present new experimental results concerning the azimuthal distributions of light and intermediate mass fragments at midrapidity for Au (100 - 800 AMeV) +Au collisions measured with the phase I setup of the FOPI detector at GSI in Darmstadt. The azimuthal distributions are investigated as a function of the collision centrality, the incident energy, the fragment charge and transverse momentum. The maximum of the azimuthal anisotropy is obtained for collisions associated with impact parameters around 7 fm. Intermediate mass fragments present a stronger out-of-plane emission signal that light fragments. We show in particular that the azimuthal anisotropy as a function of the scaled fragment transverse momentum follows an universal curve for incident energies ranging from 250 to 800 AMeV. A signature for a transition from in-plane to out-of-plane emission is evidenced at the lowest beam energies. (author).

  2. Comparison of the HeLa DNA-synthesis inhibition test and the Ames test for screening of mutagenic carcinogens

    Energy Technology Data Exchange (ETDEWEB)

    Painter, R.B.; Howard, R.

    1978-01-01

    The action of most mutagens is mediated by damage to DNA, which causes at least a temporary inhibition of DNA syntesis in mammalian cells. Assays for mammalian DNA-synthesis inhibition, both in vivo (mouse testes) and in vitro (HeLa cells), have been proposed as possible screening tests for mutagenic carcinogens. The mouse system has recently been chekced with 100 chemicals; of 88 known carcinogens and/or mutagens in this group, 76 were positive. The most generally used non-animal screening procedure is the Ames test, which uses auxotrophic strains of Salmonella typhimurium to measure mutagenesis. In this communication we summarize our results with 19 chemicals tested in HeLa cells and show that they correlate very well with the results obtained in the Ames test. Most of these chemicals act by alkylation, but an intercalator (adriamycin) is included among them as well as aflatoxin B/sub 1/, whose action is not established.

  3. Genotoxicity assessment of low-level doses of gamma radiation with the SOS chromotest and the Ames test.

    Science.gov (United States)

    Bolsunovsky, A Ya; Sinitsyna, O I; Frolova, T S; Vasyunina, E A; Dementyev, D V

    2016-07-01

    This is the first study to present data on the genotoxicity of low γ-irradiation doses for E. coli and S. typhimurium cells obtained using the SOS chromotest and the Ames test. The most pronounced effect was recorded in the first 24 h of γ-irradiation. After 72 h in the Ames test and after 96 h in the SOS chromotest, a significant effect of γ-irradiation on bacterial cells was detected. The absence of genotoxicity at the later stages can be explained by the adaptation of bacterial cells to the conditions of exposure. The findings allow the bacterial test system to be used for studying the effects of low doses at the early stages of exposure to radiation.

  4. EtherCAT高性能从站的设计与实现%Design and implementation of EtherCAT high performance slave station

    Institute of Scientific and Technical Information of China (English)

    任计羽; 范永坤; 熊皑

    2014-01-01

    The use of dedicated EtherCAT slave chip leads to high cost, low hardware integration, software complexity and difficulty in debugging, so a new hardware and software design method of EtherCAT slave station was presented. In the method, the AM3359 ARM chip was used, in which all functions including EtherCAT slave communication and application layer ware achieved, so the hardware cost was greatly reduced. A layered approach was used in software design, so it became simple and convenient to program and debug software. EtherCAT slave was implemented, at the same time, a EtherCAT network was designed to test and analyze the performance of EtherCAT slave. The EtherCAT slave station could work well.%针对使用专用芯片导致EtherCAT从站成本增加、硬件集成度下降、软件复杂、调试困难的问题,提出了新的EtherCAT从站软硬件设计方法。该方法使用AM3359 ARM芯片,在一块芯片内实现了EtherCAT从站通信功能和应用层功能,使硬件成本降低;使用分层的软件设计方法,软件编程简单,调试方便。通过搭建EtherCAT测试网络对所设计的从站功能进行测试,从站能够完好地工作。

  5. Circulating blood leukocyte gene expression profiles: Effects of the Ames dwarf mutation on pathways related to immunity and inflammation

    OpenAIRE

    Dhahbi, Joseph; Li, Xichen; Tran, Tim; Masternak, Michal M.; Bartke, Andrzej

    2007-01-01

    Aging is associated with a decline of immune competence and an increase in markers of inflammation. There is considerable evidence that inflammatory processes play a role in aging and the determination of lifespan. Hypopituitary Ames dwarf mice have extended longevity and exhibit many symptoms of delayed aging, although various aspects of immune function are suppressed in the mutants. In the present study, the expression of genes related to immunity and inflammation was compared in peripheral...

  6. AME News|金秋捷报:CCO成为AME第六本被Scopus收录的期刊

    Institute of Scientific and Technical Information of China (English)

    黄晓曼

    2015-01-01

    金秋十月,作为专注于国际医学类期刊和书籍出版的AME Publishing company再度捷报频传,10月30日,AME编辑部收到消息,Chinese Clinical Oncology(简称CCO)通过美国Content Selection&Advisory Board(CSAB)的审核,

  7. Investigation of seismicity and related effects at NASA Ames-Dryden Flight Research Facility, Computer Center, Edwards, California

    Science.gov (United States)

    Cousineau, R. D.; Crook, R., Jr.; Leeds, D. J.

    1985-01-01

    This report discusses a geological and seismological investigation of the NASA Ames-Dryden Flight Research Facility site at Edwards, California. Results are presented as seismic design criteria, with design values of the pertinent ground motion parameters, probability of recurrence, and recommended analogous time-history accelerograms with their corresponding spectra. The recommendations apply specifically to the Dryden site and should not be extrapolated to other sites with varying foundation and geologic conditions or different seismic environments.

  8. Assessing the mutagenic activities of smoke from different cigarettes in direct exposure experiments using the modified Ames Salmonella assay.

    Science.gov (United States)

    Ishikawa, Shinkichi; Kanemaru, Yuki; Nara, Hidenori; Erami, Kazuo; Nagata, Yasufumi

    2016-06-01

    The Ames assay is useful for evaluating the mutagenic potentials of chemicals, and it has been used to evaluate the mutagenic potential of cigarette smoke (CS). In vitro direct exposure systems have been developed to mimic CS exposure in the human respiratory tract, and the Ames assay has been used with such systems. Ames tests were performed using the Vitrocell(®) direct exposure system in this study. The mutagenic potentials of whole mainstream CS and gas/vapor phase fractions produced by conventional combustible cigarettes under two smoking regimens were compared. Salmonella Typhimurium TA98 and TA100 were used with and without metabolic activation, and the number of revertants induced by exposure to each CS was determined. The amount of smoke particles to which cells were exposed were also determined, and dose-response curves describing the relationships between exposure to smoke particles and the number of revertants induced were plotted. The slopes of linear regressions of the dose-response curves were determined, and the slope for each CS was used as a mutagenic activity index for that CS. A new heated cigarette was also tested and smoke from the heated cigarette had a lower mutagenic activity in TA98 and TA100 with metabolic activation than did the conventional CS. The results indicate that the direct exposure system and the Ames test can be used to determine the mutagenic potentials of CS produced by different cigarettes under different conditions (i.e., using different Salmonella Typhimurium strains with and without metabolic activation, and using different smoking conditions).

  9. Biographical sketch: Nosrat Ollah Ameli, MB, ChB (Hons), ChM (Birm), FICS, FRCS (Eng).

    Science.gov (United States)

    Alimi, Marjan; Rahimi-Movaghar, Vafa

    2012-10-01

    Nosrat Ollah Ameli (1913-2010) was one of the pioneers in Iranian neurosurgery. After training in England in the 1950s, Ameli returned to his country to found the Darioush Kabir Hospital, where he started the first neurosurgical ward in collaboration with Prof. E. Samiy. Here he applied his genius and innovation to develop unique approaches to the management of challenging neurosurgical techniques, in the context of limited resource available at that time. He started the training of neurosurgeons in Iran. He was internationally recognised being elected as a vice president of the World Federation of Neurosurgical Societies (WFNS). His efforts extended beyond neurosurgery to many other fields. He published extensively in international peer reviewed medical journals around the world and contributed to the foundation of Acta Medica Iranica journal, the first scientific medical journal in English published by Tehran University of Medical Sciences. His efforts to improve medical education in Iran continued even through his years of retirement. This article recounts Nosrat Ollah Ameli's many contributions to Iran's medical education as well as his achievements as a neurosurgeon.

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

    Science.gov (United States)

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

    1997-11-01

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

  11. SYNTHESIS OF ALLYL PHENYL ETHER AND CLAISEN REARRANGEMENT

    Directory of Open Access Journals (Sweden)

    Gagik Torosyan

    2011-12-01

    Full Text Available It has been established the possibility for phenol allylation on natural zeolites and them analogs. Here is demonstrated the synthesis of allyl phenol, which has wide industrial applications. The offered method in comparison with the traditional methods has more advantages – higher selectivity, smaller material and power resources consumption. It has been obtained the mixture of allylating phenols (30% in general with allyl phenyl ether (1 with 80% yields. At 600 K is obtained allylphenyl ether, at 700 K beginning the formation of allyl phenols, which is the result of direct C-allylation of the aromatic ring. It has been investigated the possibility of Claisen rearrangement in the same conditions. All of that are established by gas-liquid chromatography and liquid chromatography data.

  12. [Ethylene glycol and propylene glycol ethers - Reproductive and developmental toxicity].

    Science.gov (United States)

    Starek-Świechowicz, Beata; Starek, Andrzej

    2015-01-01

    Both ethylene and propylene glycol alkyl ethers (EGAEs and PGAEs, respectively) are widely used, mainly as solvents, in industrial and household products. Some EGAEs demonstrate gonadotoxic, embriotoxic, fetotoxic and teratogenic effects in both humans and experimental animals. Due to the noxious impact of these ethers on reproduction and development of organisms EGAEs are replaced for considerably less toxic PGAEs. The data on the mechanisms of testicular, embriotoxic, fetotoxic and teratogenic effects of EGAEs are presented in this paper. Our particular attention was focused on the metabolism of some EGAEs and their organ-specific toxicities, apoptosis of spermatocytes associated with changes in the expression of various genes that code for oxidative stress factors, protein kinases and nuclear hormone receptors.

  13. Synthesis of hydroxylated and methoxylated polybrominated diphenyl ethers

    Institute of Scientific and Technical Information of China (English)

    ZHENG Ke-wen; GAO Li-ping; CAO Jie; YU Hai-wen; ZHANG Zhang

    2009-01-01

    Hydroxylated/methoxylated polybrominated diphenyl ethers (OH/MeO-PBDEs) are not only detected as natural products, but also regarded as metabolites formed from polybrominated diphenyl ethers (PBDEs), which are widely used as flame-retardants in various materials. The aim of the present study was to synthesize authentic OH-PBDEs and MeO-PBDEs, as reference standards for environmental exploration. Twenty OH-PBDEs and their corresponding MeO-PBDEs containing three to six bromine atoms were synthesized via a trial of reactions including coupling, oxidation, bromination, methylation, etc. The products were characterized by GC-MS and 1H-NMR spectroscopy in the work. As results show, all compounds synthesized were up to 99% on purity and be reqarded as authentic standards for detecting the chemical pollutants in the emvironment.

  14. Synthesis of Ethers via Reaction of Carbanions and Monoperoxyacetals

    Science.gov (United States)

    2015-01-01

    Although transfer of electrophilic alkoxyl (“RO+”) from organic peroxides to organometallics offers a complement to traditional methods for etherification, application has been limited by constraints associated with peroxide reactivity and stability. We now demonstrate that readily prepared tetrahydropyranyl monoperoxyacetals react with sp3 and sp2 organolithium and organomagnesium reagents to furnish moderate to high yields of ethers. The method is successfully applied to the synthesis of alkyl, alkenyl, aryl, heteroaryl, and cyclopropyl ethers, mixed O,O-acetals, and S,S,O-orthoesters. In contrast to reactions of dialkyl and alkyl/silyl peroxides, the displacements of monoperoxyacetals provide no evidence for alkoxy radical intermediates. At the same time, the high yields observed for transfer of primary, secondary, or tertiary alkoxides, the latter involving attack on neopentyl oxygen, are inconsistent with an SN2 mechanism. Theoretical studies suggest a mechanism involving Lewis acid promoted insertion of organometallics into the O–O bond. PMID:26560686

  15. CATALYSTS FOR HIGH CETANE ETHERS AS DIESEL FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Kamil Klier; Richard G. Herman; James G.C. Shen; Qisheng Ma

    2000-08-31

    A novel 1,2-ethanediol, bis(hydrogen sulfate), disodium salt precursor-based solid acid catalyst with a zirconia substrate was synthesized and demonstrated to have significantly enhanced activity and high selectivity in producing methyl isobutyl ether (MIBE) or isobutene from methanol-isobutanol mixtures. The precursor salt was synthesized and provided by Dr. T. H. Kalantar of the M.E. Pruitt Research Center, Dow Chemical Co., Midland, MI 48674. Molecular modeling of the catalyst synthesis steps and of the alcohol coupling reaction is being carried out. A representation of the methyl transfer from the surface activated methanol molecule (left) to the activated oxygen of the isobutanol molecule (right) to form an ether linkage to yield MIBE is shown.

  16. Structural Study of Mismatched Disila-Crown Ether Complexes

    Directory of Open Access Journals (Sweden)

    Kirsten Reuter

    2017-02-01

    Full Text Available Mismatched complexes of the alkali metals cations Li+ and Na+ were synthesized from 1,2-disila[18]crown-6 (1 and 2 and of K+ from 1,2,4,5-tetrasila[18]crown-6 (4. In these alkali metal complexes, not all crown ether O atoms participate in the coordination, which depicts the coordination ability of the C-, Si/C-, and Si-bonded O atoms. Furthermore, the inverse case—the coordination of the large Ba2+ ion by the relatively small ligand 1,2-disila[15]crown-5—was investigated, yielding the dinuclear complex 5. This structure represents a first outlook on sandwich complexes based on hybrid crown ethers.

  17. Intrinsic Kinetics of Dimethyl Ether Synthesis from Syngas

    Institute of Scientific and Technical Information of China (English)

    Zhaoguang Nie; Hongwei Liu; Dianhua Liu; Weiyong Ying; Dingye Fang

    2005-01-01

    The intrinsic kinetics of dimethyl ether (DME) synthesis from syngas over a methanol synthesis catalyst mixed with methanol dehydration catalyst has been investigated in a tubular integral reactor at 3-7 MPa and 220-260 ℃. The three reactions including methanol synthesis from CO and H2, CO2 and H2, and methanol dehydration were chosen as the independent reactions. The L-H kinetic model was presented for dimethyl ether synthesis and the parameters of the model were obtained by using simplex method combined with genetic algorithm. The model is reliable according to statistical analysis and residual error analysis. The synergy effect of the reactions over the bifunctional catalyst was compared with the effect for methanol synthesis catalyst under the same conditions based on the model. The effects of syngas containing N2 on the reactions were also simulated.

  18. A Facile Synthesis of Two Sesquiterpenes Methyl Ether

    Institute of Scientific and Technical Information of China (English)

    DU Zhen-Ting; ZHANG Yan-Mei; WANG Zi-Kun; WU Tong-Xing; PAN Xin-Fu

    2003-01-01

    @@ Bisabolane sesquiterpenes are a big family of naturally occurring products with significantly biological activities most of which can be separated from Chinese traditional medicines. Parahigginone (1a) was firstly separated as a bisabolane by Shen Y. C. et al. from the Taiwan marine sponges in 1999, [1] it shows very promising antitumor activity.[1] As far as we know, there is no synthetic report on it. Curcuphenol (2a) was a cytotoxic sesquiterpene which was first discovered in Pseudopterogorgia rigida[2,3] which has been synthesized by Frank[2] and Tsutomu[4] before. In order to study the relationship between the structures and the activities, we have synthesized parahiggi none methyl ether (1) and curcuphenol methyl ether (2) in six steps successfully, and the stereoselective synthesis is carried out in progress.

  19. Numerical investigation on the effect of injection pressure on the internal flow characteristics for diethyl ether, dimethyl ether and diesel fuel injectors using CFD

    Directory of Open Access Journals (Sweden)

    Vijayakumar Thulasi

    2011-01-01

    Full Text Available The spray characteristics of the diesel fuel are greatly affected by the cavitation formed inside the injector due to the high pressure differential across the nozzle. Many researchers across the globe are exploring the potential of using diethyl ether and dimethyl ether as an alternate for diesel fuel to meet the strict emission norms. Due to the variation in the fuel properties the internal flow characteristics in injectors for ether fuels are expected to be different from that of the diesel fuel. In this paper computational technique is used to study and compare the internal flow characteristics of diethyl ether, dimethyl ether and diesel fuel. The two phase flow model considering the fuel as a mixture of liquid and vapor is adopted for the simulation study. The injection pressure is varied from 100 to 400 bar and the flow characteristics of all three fuels are simulated and compared. Results indicate that all three fuels have distinct cavitating patterns owing to different property values. The dimethyl ether is found to be more cavitating than diesel and diethyl ether fuels as expected. The mass of fuel injected are found to be decreasing for the ether fuels when compared with diesel fuel at all injection pressures.

  20. NETWORK CROWN ETHER POLYMERS WITH CENTRIC FUNCTIONAL GROUP (Ⅳ) SYNTHESIS OF NETWORK CROWN ETHER POLYMER WITH PENDANT DIETHYLAMINO THIAALKYL GROUP AND ITS PLATINUM COMPLEX

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuanyin; MENG Lingzhi; YIN Yihua; GENG Chengai

    1994-01-01

    The title polymer was prepared from 5-diethylamino-3-thia-pentyl glycidyl ether and diethylene glycol bisglycidyl ether via ring-opening copolymerization. It was found that this reaction could be catalyzed by sodium, but not Lewis acid. The obtained polymer can coordinate with platinum compound, and the platinum complex is a new kind of catalyst for the hydrosilylation of olefins with triethoxysilane.

  1. EL2595 EtherCAT端子模块

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    全新的EtherCAT端子模块EL2595用作控制“LED镇流器”,可直接连接LED灯。端子模块宽度仅为12mm,集成了控制、调光和监测功能。它可以连接各种电压和电流范围的灯具,

  2. Synthesis and adsorption properties of chitosan-crown ether resins

    Institute of Scientific and Technical Information of China (English)

    彭长宏; 陈艺锋; 唐谟堂

    2003-01-01

    Two kinds of novel chitosan-crown ether resins, Schiff base type chitosan-benzo-15-crown-5 (CTS-B15)and chitosan-benzo-18-crown-6 (CTS-B18), were synthesized through the reaction between -NH2 in chitosan and -CHO in 4′-formyl benzo-crown ethers. Their structures were characterized by elemental analysis and FT-IR spectra analysis. The elemental analysis results show that the mass fractions of nitrogen in CTS-B15 and CTS-B18 are much lower than those of chitosan. The results of FT-IR spectra of CTS-B15 and CTS-B18 reveal that there exist characteristic peak of C= N, N-H and Ar, and characteristic peak of pyr anoside in the chain of chitosan-crown ether resins, showing that the structures of chitosan-crown ethers are as expected. The adsorption properties of CTS-B15 and CTS-B18 for Pd2+ , Cu2 + and Hg2+ were studied and the experimental results show that these adsorbents have both good adsorption characterization and especially high particular adsorption selectivity for Pd2+ when Cu2+ and Hg2+ are in coexistence, and the coefficients of selectivity of CTS-B15 and CTS-B18 for metal ions are KPd2+/cu2+ =7.56, KPd2+/Hg2+ = 68.00, Kcu2+/Hg2+ = 9.00 and KPd2+/cu2+ = 6.00, KPd2+/Hg2+ = 19. 00, Kcu2+/Hg2+ = 3.00, respectively.

  3. Patch test with ether extracts in salicaceae allergy

    Directory of Open Access Journals (Sweden)

    Sawhney M

    2002-01-01

    Full Text Available A total of 23 cases suggestive of airborne contact dermatitis were patch tested with ether extracts of flowers and leaves of populus sp. and salix sp. in a study conducted in Ladakh at an altitude of 3445 meters above sea level. Overall positivity was found in 12 (52.17%, with populus sp. alone in 7 (30. 43%, salix sp. alone in 4 17.39% and to both in one (8.33%.

  4. Cross sections for electron collisions with dimethyl ether

    OpenAIRE

    Sugohara, RT; Homem, MGP; Iga, I; de Souza, GLC; MACHADO, LE; Ferraz, JR; dos Santos, AS; Brescansin, LM; Lucchese, RR; Lee, MT

    2013-01-01

    We report a joint theoretical-experimental investigation of electron collision with dimethyl ether (DME) in the low- and intermediate-energy ranges. Experimental absolute differential, integral, and momentum-transfer cross sections for elastic e(-)-DME scattering are reported in the 100-1000 eV energy range. Our measurements were performed using a crossed electron-beam-molecular-beam geometry. The angular distribution of the scattered electrons was converted to absolute cross section using th...

  5. 12-Crown-4 Ether Improves Rechargeable Lithium Cells

    Science.gov (United States)

    Nagasubramanian, Ganesan; Attia, Alan I.

    1992-01-01

    Experiments show addition of 12-crown-4 ether (12Cr4) to thin film of polyethylene oxide (PEO) and LiBF4 reduces charge-transfer resistance of film and enhances performance of electrochemical cell in which film is electrolyte, anode is lithium, and cathode is LixCoO2. By increasing conductivity of the electrolyte, 12Cr4 reduces polarization loss; enabling cell to sustain higher current. Result is new type of rechargeable lithium cell.

  6. 高速无线EtherNet/IP模块

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    ProSoft Technology专为Control Logix平台设计的高速无线Ether Net/IP模块(MVI56-WA-ElP)使无线以太网连接和编程成为可能。无需打开工厂底层设备箱保护你的设备,并且减少由于弧光的危险带来的停工期。

  7. Study on Synergy Effect in Dimethyl Ether Synthesis from Syngas

    Institute of Scientific and Technical Information of China (English)

    王志良; 刁杰; 王金福; 金涌

    2001-01-01

    Influence of reaction temperature, pressure and space velocity on the direct synthesis of dimethyl ether (DME) from syngas is studied in an isothermal fixed-bed reactor. The catalyst is a physical mixture of C30 copper-based methanol (MeOH) synthesis catalyst and ZSM-5 dehydration catalyst. The experimental results show that the chemical synergy between methanol synthesis reaction and methanol dehydration reaction is evident. The conversion of carbon monoxide is over 90%.

  8. Homogeneous Charge Compression Ignition Combustion of Dimethyl Ether

    OpenAIRE

    Pedersen, Troels Dyhr; Schramm, Jesper

    2011-01-01

    This thesis is based on experimental and numerical studies on the use of dimethyl ether (DME) in the homogeneous charge compression ignition (HCCI) combustion process. The first paper in this thesis was published in 2007 and describes HCCI combustion of pure DME in a small diesel engine. The tests were designed to investigate the effect of engine speed, compression ratio and equivalence ratio on the combustion timing and the engine performance. It was found that the required compression ratio...

  9. Surface Lander Missions to Mars: Support via Analysis of the NASA Ames Mars General Circulation Model

    Science.gov (United States)

    Murphy, James R.; Bridger, Alison F.C.; Haberle, Robert M.

    1997-01-01

    We have characterized the near-surface martian wind environment as calculated with a set of numerical simulations carried out with the NASA Ames Mars General Circulation Model (Mars GCM). These wind environments are intended to offer future spacecraft missions to the martian surface a data base from which to choose those locations which meet the mission's criteria for minimal near surface winds to enable a successful landing. We also became involved in the development and testing of the wind sensor which is currently onboard the Mars-bound Pathfinder lander. We began this effort with a comparison of Mars GCM produced winds with those measured by the Viking landers during their descent through the martian atmosphere and their surface wind measurements during the 3+ martian year lifetime of the mission. Unexpected technical difficulties in implementing the sophisticated Planetary Boundary Layer (PBL) scheme of Haberle et al. (1993) within the Mars GCM precluded our carrying out this investigation with the desired improvement to the model's treatment of the PBL. Thus, our results from this effort are not as conclusive as we had anticipated. As it turns out, similar difficulties have been experienced by other Mars modelling groups in attempting to implement very similar PBL routines into their GCMs (Mars General Circulation Model Intercomparison Workshop, held at Oxford University, United Kingdom, July 22-24, 1996; organized by J. Murphy, J. Hollingsworth, M. Joshi). These problems, which arise due to the nature of the time stepping in each of the models, are near to being resolved at the present. The model discussions which follow herein are based upon results using the existing, less sophisticated PBL routine. We fully anticipate implementing the tools we have developed in the present effort to investigate GCM results with the new PBL scheme implemented, and thereafter producing the technical document detailing results from the analysis tools developed during this

  10. Biochemical and structural characterization of alanine racemase from Bacillus anthracis (Ames

    Directory of Open Access Journals (Sweden)

    Hill Ryan E

    2009-08-01

    Full Text Available Abstract Background Bacillus anthracis is the causative agent of anthrax and a potential bioterrorism threat. Here we report the biochemical and structural characterization of B. anthracis (Ames alanine racemase (AlrBax, an essential enzyme in prokaryotes and a target for antimicrobial drug development. We also compare the native AlrBax structure to a recently reported structure of the same enzyme obtained through reductive lysine methylation. Results B. anthracis has two open reading frames encoding for putative alanine racemases. We show that only one, dal1, is able to complement a D-alanine auxotrophic strain of E. coli. Purified Dal1, which we term AlrBax, is shown to be a dimer in solution by dynamic light scattering and has a Vmax for racemization (L- to D-alanine of 101 U/mg. The crystal structure of unmodified AlrBax is reported here to 1.95 Å resolution. Despite the overall similarity of the fold to other alanine racemases, AlrBax makes use of a chloride ion to position key active site residues for catalysis, a feature not yet observed for this enzyme in other species. Crystal contacts are more extensive in the methylated structure compared to the unmethylated structure. Conclusion The chloride ion in AlrBax is functioning effectively as a carbamylated lysine making it an integral and unique part of this structure. Despite differences in space group and crystal form, the two AlrBax structures are very similar, supporting the case that reductive methylation is a valid rescue strategy for proteins recalcitrant to crystallization, and does not, in this case, result in artifacts in the tertiary structure.

  11. Assessment of mutagenic potential of pyrolysis biochars by Ames Salmonella/mammalian-microsomal mutagenicity test.

    Science.gov (United States)

    Anjum, Reshma; Krakat, Niclas; Toufiq Reza, M; Klocke, Michael

    2014-09-01

    Biochar is of raising interest in sustainable biomass utilization concepts. Particularly biochar derived from pyrolysis attaches important agricultural capacities mandatory for an improved carbon sequestration, soil fertility and amelioration, respectively. In fact, large scale field trials and commercial business with biochar materials have already been started but still only few are known about the mutagenic potential of biochars produced. In this study hemp bedding and wood pellet biomass were used for biochar production by pyrolysis. The total concentrations of polycyclic aromatic hydrocarbons (PAHs) were 34.9µgg(-1) of dry mass and 33.7µgg(-1) of dry mass for hemp biochar and wood biochar, respectively. The concentration of PAHs in tar produced during wood carbonization was 17.4µgg(-1). The concentrations of phenolic compounds were 55µgg(-1) and 8.3µgg(-1) for hemp and wood biochar, respectively. Salmonella/microsomal mutagenicity tests (i.e. Ames test) revealed a maximum mutagenicity for hemp biochar extracts with strains TA97, TA98 and TA100 in the presence and absence of liver microsomal fractions, respectively. Wood biochar and tar extract exhibited maximum mutagenicity with strains TA98 and T100 both in the presence and absence of liver microsomal fraction. The reversion of the applied tester strains increased in the presence and absence of liver microsomal fractions with an increasing dose of hemp biochar extract up to 2µl per plate and decreased at a concentration of 2.5µl per plate. For wood biochar and tar extracts, reversion of tester strains increased both in the presence and absence of S9 at extract concentrations of 4µl per plate and declined at a dose of 8µl per plate. By this study a significant higher mutagenic potential for hemp biochar compared to wood biochar and tar could be observed suggesting careful application in soil melioration.

  12. General overview of the theories used in assessment: AMEE Guide No. 57.

    Science.gov (United States)

    Schuwirth, Lambert W T; van der Vleuten, Cees P M

    2011-01-01

    There are no scientific theories that are uniquely related to assessment in medical education. There are many theories in adjacent fields, however, that can be informative for assessment in medical education, and in the recent decades they have proven their value. In this AMEE Guide we discuss theories on expertise development and psychometric theories, and the relatively young and emerging framework of assessment for learning. Expertise theories highlight the multistage processes involved. The transition from novice to expert is characterised by an increase in the aggregation of concepts from isolated facts, through semantic networks to illness scripts and instance scripts. The latter two stages enable the expert to recognise the problem quickly and form a quick and accurate representation of the problem in his/her working memory. Striking differences between experts and novices is not per se the possession of more explicit knowledge but the superior organisation of knowledge in his/her brain and pairing it with multiple real experiences, enabling not only better problem solving but also more efficient problem solving. Psychometric theories focus on the validity of the assessment - does it measure what it purports to measure and reliability - are the outcomes of the assessment reproducible. Validity is currently seen as building a train of arguments of how best observations of behaviour (answering a multiple-choice question is also a behaviour) can be translated into scores and how these can be used at the end to make inferences about the construct of interest. Reliability theories can be categorised into classical test theory, generalisability theory and item response theory. All three approaches have specific advantages and disadvantages and different areas of application. Finally in the Guide, we discuss the phenomenon of assessment for learning as opposed to assessment of learning and its implications for current and future development and research.

  13. SYBR Gold and SYBR Green II are not mutagenic in the Ames test.

    Science.gov (United States)

    Kirsanov, Kirill I; Lesovaya, Ekaterina A; Yakubovskaya, Marianna G; Belitsky, Gennady A

    2010-06-17

    Favorable photo-physical properties and high affinity to nucleic acids make new fluorescent cyanine dyes of the SYBR-type particularly useful for DNA and RNA visualization. The growing popularity of SYBR-type dyes is also explained by the fact that removal of the dye from the nucleic acids by ethanol precipitation is more efficient and less time-consuming than the phenol-chloroform extraction applied for the widely used phenanthridine DNA stain, ethidium bromide. To evaluate the safety of nucleic acid staining by SYBR Gold and SYBR Green II we compared the mutagenicity of these compounds, with characteristics corresponding to those of ethidium bromide, by use of the Salmonella/mammalian microsome reverse-mutation assays (Ames test). SYBR Green II and SYBR Gold did not show mutagenicity either in frame-shift or in base-substitution indicator strains, TA98 and TA100, respectively. These results were observed both in the presence and in the absence of supernatant from a rat-liver homogenate S9. Mutagenicity of these stains was not observed although their toxic concentration was reached. Toxic effects of SYBR Green II and SYBR Gold were seen approximately at the same molar concentrations as reported previously for SYBR Green I. As expected, ethidium bromide revealed strong mutagenicity with a maximum increase of 60-fold above the vehicle controls in the frame-shift indicator strain TA98 in the presence of rat-liver S9 extract. Thus, SYBR Gold and SYBR Green II do not show mutagenicity in our tests, even at toxic doses, and these DNA stains represent safer alternatives to ethidium bromide for nucleic acid visualization.

  14. Bacillus cereus G9241 Makes Anthrax Toxin and Capsule like Highly Virulent B. anthracis Ames but Behaves like Attenuated Toxigenic Nonencapsulated B. anthracis Sterne in Rabbits and Mice

    Science.gov (United States)

    2011-08-01

    Microbiology. All Rights Reserved. Bacillus cereus G9241 Makes Anthrax Toxin and Capsule like Highly Virulent B. anthracis Ames but Behaves like...G9241 for mice requires the presence of both plasmids. The Bacillus cereus group, of which Bacillus anthracis, Bacil- lus thuringiensis , and B... Bacillus cereus G9241 Makes Anthrax Toxin and Capsule like Highly Virulent B. anthracis Ames but Behaves like Attenuated Toxigenic Nonencapsulated B

  15. Diethyl Ether Production Process with Various Catalyst Type

    Directory of Open Access Journals (Sweden)

    Widayat

    2013-01-01

    Full Text Available Several H-zeolite and HZSM-5 catalysts was preparated and their characters have also been investigated. H-zeolit Catalyst was preparated from Natural Zeolite that obtained from Malang District and Gunung Kidul District. Diethyl ether was produced by Ethanol with concentration of 95%. This research use fixed bed reactor that 1 gram of catalyst as bed catalyst, atmospheric pressure and temperature 140oC as the operating condition. Ethanol vapor from vaporization tank was driven by 200 ml/min Nitrogen stream. The responds in this research is liquid product concentration; diethyl ether, ethanol, methanol and water concentration. The results showed that the largest ethanol conversion was produced by the use of 56.44% HZSM-5 and the largest yield of diethyl ether diethyl was produced by the use of alumina and H-zeolite catalyst. The larger ratio between natural zeolite with HCl solvent will produce the larger surface area of catalyst and ethanol conversion. The largest ethanol conversion was produced at reactan ratio 1:20.

  16. Thermolysis of surface-immobilized phenethyl phenyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Britt, P.F.; Buchanan, A.C. III; Hitsman, V.M.

    1991-01-01

    Our research has focused on modeling the constraints on free-radical reactions that might be imposed in coal as a consequence of its cross-linked macromolecular structure by covalently bonding diphenylalkanes to an inert silica surface. A surface-immobilized phenethyl phenyl ether ({approx}PhCH{sub 2}CH{sub 2}POh, or {approx}PPE-3) has been prepared as a model for ether linkages in lignin by the condensation of p-HOPhCH{sub 2}CH{sub 2}OPh with the surface hydroxyls of a high purity fumed silica. Thermolysis of {approx}PPE-3 at saturation surface coverage at 375{degree}C produces {approx}PhCH = CH{sub 2} and PhOH as the major products which are consistent with the proposed free-radical chain mechanism for the decomposition of fluid-phase phenethyl phenyl ether. However, significant quantities of {approx}PhCH{sub 3} and PhCHO (ca. 18% of the products) are produced indicating the emergence of a new reaction pathway on the surface. The mechanism for the decomposition of {approx}PPE-3 will be discussed in light of this new information. 18 refs., 1 fig.

  17. Radical addition-initiated domino reactions of conjugated oxime ethers.

    Science.gov (United States)

    Ueda, Masafumi

    2014-01-01

    The application of conjugated oxime ethers to the synthesis of complex chemical scaffolds using domino radical reactions has been described in detail. The triethylborane-mediated hydroxysulfenylation reaction allows for the regioselective construction of a carbon-sulfur bond and a carbon-oxygen bond in a single operation for the formation of β-hydroxy sulfides. This reaction proceeds via a radical pathway involving regioselective thiyl addition and the subsequent trapping of the resulting α-imino radical with O₂, where the imino group enhances the stability of the intermediate radical. Hydroxyalkylation reactions that occur via a carbon radical addition reaction followed by the hydroxylation of the resulting N-borylenamine with O₂ have also been developed. We investigated sequential radical addition aldol-type reactions in detail to explore the novel domino reactions that occur via the generation of N-borylenamine. The radical reaction of a conjugated oxime ether with triethylborane in the presence of an aldehyde affords γ-butyrolactone via sequential processes including ethyl radical addition, the generation of N-borylenamine, an aldol-type reaction with an aldehyde, and a lactonization reaction. A novel domino reaction has also been developed involving the [3,3]-sigmatropic rearrangement of N-boryl-N-phenoxyenamine. The triethylborane-mediated domino reactions of O-phenyl-conjugated oxime ethers afforded the corresponding benzofuro[2,3-b]pyrrol-2-ones via a radical addition/[3,3]-sigmatropic rearrangement/cyclization/lactamization cascade.

  18. Preparation and antioxidant activity of tyrosyl and homovanillyl ethers.

    Science.gov (United States)

    Madrona, A; Pereira-Caro, G; Bravo, L; Mateos, R; Espartero, J L

    2011-12-01

    Preparation of tyrosyl and homovanillyl lipophilic derivatives was carried out as a response to the food industry's increasing demand for new synthetic lipophilic antioxidants. Tyrosyl and homovanillyl ethers were synthesized in high yields by a three-step procedure starting from tyrosol (Ty) and homovanillic alcohol (HMV). The antioxidant activity of these new series of alkyl tyrosyl and homovanillyl ethers was evaluated by the Rancimat test in a lipophilic food matrix and by the FRAP, ABTS and ORAC assays and compared to free Ty and HMV as well as two antioxidants widely used in the food industry, butylhydroxytoluene (BHT) and α-tocopherol. The results pointed out the higher activity of homovanillyl series in comparison with tyrosyl series with all the assayed methods. However, while both synthetic series were less antioxidant than BHT and α-tocopherol in a lipophilic matrix after their Rancimat test evaluation, homovanillyl alkyl ethers showed the best reducing power and radical scavenging activity of all evaluated compounds. This batch of synthetic lipophilic compounds, derived from biologically active compounds such as Ty and HMV, provide interesting and potentially bioactive compounds.

  19. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor.

    Science.gov (United States)

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha

    2014-03-25

    The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion(®). The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion(®), resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria.

  20. Rheological and electrical percolation in melt-processed poly(ether ether ketone)/multi-wall carbon nanotube composites

    Science.gov (United States)

    Bangarusampath, D. S.; Ruckdäschel, Holger; Altstädt, Volker; Sandler, Jan K. W.; Garray, Didier; Shaffer, Milo S. P.

    2009-11-01

    Multi-wall carbon nanotubes were dispersed homogeneously throughout a poly(ether ether ketone) matrix by melt processing. The influence of nanotube content on both rheological and electrical properties was analysed. The dynamic storage modulus, G', shows a characteristic solid-like behavior above 1 wt% nanotubes. A sharp transition from an electrically insulating to a conductive composite was observed between 1 and 1.5 wt%. By applying a power-law relation, the rheological and electrical percolation thresholds were found to be 0.9 wt%, and 1.3 wt%, respectively. Considering this data, Guth's filler reinforcement theory provides a valuable estimation of the aspect ratio of the nanotubes after processing and indicates substantial length degradation during the dispersion process.

  1. Poly (ether ether ketone) membranes for fuel cells; Membranas de poli (eter eter cetona) sulfonado para celulas a combustivel

    Energy Technology Data Exchange (ETDEWEB)

    Marrero, Jacqueline C.; Gomes, Ailton de S.; Filho, Jose C.D., E-mail: jacquecosta@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Hui, Wang S. [Universidade de Sao Paulo (USP), Sao Paulo, SP (Brazil); Oliveira, Vivianna S. de [Escola Tecnica Rezende-Rammel, Rio de Janeiro, RJ (Brazil)

    2015-07-01

    Polymeric membranes were developed using a SPEEK polymer matrix (sulphonated poly (ether ether ketone)), containing hygroscopic particles of zirconia (Zr) (incorporated by sol-gel method), for use as electrolyte membranes in fuel cells. SPEEK with different sulfonation degrees were used: 63 and 86%. The thermal analysis (TGA and DSC) was carried out to characterize the membranes and electrochemical impedance spectroscopy (EIS) was carried out to evaluating the proton conductivity of the membranes. Additional analysis were underway in order to characterize these membranes, which include: X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) in order to evaluate the influence of zirconia and sulfonation degree on the properties of the membranes. (author)

  2. An estimation of fatigue life for a carbon fibre/poly ether ether ketone hip joint prosthesis.

    Science.gov (United States)

    Akay, M; Aslan, N

    1995-01-01

    A fracture mechanics approach was applied to estimate the life of a prosthesis injection moulded from short carbon fibre reinforced poly ether ether ketone. Flexural modulus and strength, fracture toughness, fatigue endurance limit, fatigue crack growth rate and threshold stress intensity factor were determined. The dimensions of the test pieces were selected to yield fibre orientation and fibre length distributions similar to those obtained in the prosthesis. Stress levels generated in the prosthesis under different activities were estimated by conducting three-dimensional finite element analysis. It was shown by a fracture mechanics approach that a fatigue failure due to the propagation of an embedded elliptical slit, under these stresses, would be unlikely for a crack length smaller than 1.85 mm. However, the cement would fail under the same conditions, irrespective of the type of the prosthesis employed.

  3. Preparation of poly(ether ether ketone)-based polymer electrolytes for fuel cell membranes using grafting technique

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Shin; Suzuki, Yasuyuki [Conducting Polymer Materials Group, Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370 1292 (Japan); Maekawa, Yasunari [Conducting Polymer Materials Group, Environment and Industrial Materials Research Division, Quantum Beam Science Directorate, Japan Atomic Energy Agency (JAEA), 1233 Watanuki, Takasaki, Gunma 370 1292 (Japan)], E-mail: maekawa.yasunari@jaea.go.jp

    2008-05-15

    Poly(ether ether ketone) (PEEK)-based polymer electrolyte membranes (PEMs) was successfully prepared by radiation grafting of a styrene monomer into PEEK films and the consequent selective sulfonation of the grafting chains in the film state. Using milder sulfonation, the sulfonation reactions proceeded at the grafted chains in preference to the phenylene rings of PEEK main chains; as a result, the grafted films could successfully transform to a PEM with conductivity of more than 0.1 S/cm. The ion exchange capacity (IEC) and conductivity of the grafted PEEK electrolyte membranes were controlled to the ranges of 1.2-2.9 mmol/g and 0.03-0.18 S/cm by changing the grafting degree. It should be noted that this is the first example of directly transforming super-engineering plastic films into a PEM using radiation grafting.

  4. ETBE (ethyl tert butyl ether) and TAME (tert amyl methyl ether) affect microbial community structure and function in soils.

    Science.gov (United States)

    Bartling, Johanna; Esperschütz, Jürgen; Wilke, Berndt-Michael; Schloter, Michael

    2011-03-15

    Ethyl tert butyl ether (ETBE) and tert amyl methyl ether (TAME) are oxygenates used in gasoline in order to reduce emissions from vehicles. The present study investigated their impact on a soil microflora that never was exposed to any contamination before. Therefore, soil was artificially contaminated and incubated over 6 weeks. Substrate induced respiration (SIR) measurements and phospholipid fatty acid (PLFA) analysis indicated shifts in both, microbial function and structure during incubation. The results showed an activation of microbial respiration in the presence of ETBE and TAME, suggesting biodegradation by the microflora. Furthermore, PLFA concentrations decreased in the presence of ETBE and TAME and Gram-positive bacteria became more dominant in the microbial community.

  5. Influence of the angle between two crown ether moieties on supramolecular copolymerization of bis(crown ether)s and bisparaquat homoditopic monomers

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Bis(crown ether) homoditopic monomers containing two bis(p-phenylene)-34-crown-10 moieties with different angles(180° for monomer 3,120°for monomer 4,and 60°for monomer 5) and a complementary bisparaquat homoditopic monomer(7) were designed and synthesized.The three bis(crown ether) monomers could organize into linear supramolecular polymers in concentrated solutions in CHCl3/CH3CN with the bisparaquat monomer 7,as demonstrated by 1 H NMR and viscosity studies. The pseudorotaxanes or supramolecular polymers formed from 3+7 and 4+7 had larger values of Ka,p,n,slope 1,and slope 2 than those of 5+7.This result was attributed to the greater steric hindrance of compound 5 than that of 3 and 4,which resulted in less effective formation of linear supramolecular polymers from 5 with compound 7 than those from compounds 3 and 4 with compound 7,as also demonstrated by UV-vis method.

  6. A facile synthesis of highly stable multiblock poly(arylene ether)s based alkaline membranes for fuel cells

    Science.gov (United States)

    Jasti, Amaranadh; Shahi, Vinod K.

    2014-12-01

    Herein, we are disclosing simple route for the preparation of alkaline membranes (AMs) based on aminated multiblock poly(arylene ether)s (AMPEs) synthesized by nucleophilic substitution-poly condensation followed by quaternization and alkalization reactions. In this procedure, four quaternary ammonium groups are successfully introduced without use of carcinogenic reagents such as chloromethylmethyl ether (CMME). Hydrophilic/hydrophobic phase separation is responsible for their high hydroxide conductivity (∼150 mS cm-1 at 80 °C) due to development of interconnected ion transport pathway. AMs are exhibiting good alkaline stability due to the presence of two vicinal quaternary ammonium groups and avoid degradation such as Sommelet-Hauser rearrangement and Hofmann elimination. Vicinal quaternary ammonium groups also resist nucleophilic (OH-) attack and suppress the Stevens rearrangement as well as SN2 substitution reaction due to stearic hindrance. Optimized AM (AMPE-M20N15 (55% DCM)) exhibits about 0.95 V open circuit voltage (OCV) and 48.8 mW cm-2 power density at 65 °C in alkaline direct methanol fuel cell (ADMFC) operation. These results suggest promising begin for the preparation of stable and conductive AMs for ADMFC applications and useful for developing hydroxide conductive materials.

  7. Crystallization Kinetics and Melting Behavior of PA1010/Ether-based TPU Blends

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shu-ling; ZHAO Yan; SUN Xiao-bo; JIANG Zhen-hua; WU Zhong-wen; WANG Gui-Bin

    2007-01-01

    Polyamide 1010(PA1010)/thermoplastic poly(ether urethane) elastomer(ether-based TPU) blends were prepared via melt extrusion. The crystallization kinetics and melting behavior of PA1010/ether-based TPU blends were systematically investigated using differential scanning calorimetry. The crystallization kinetics results show that the addition of ether-based TPU hinders the crystallization of PA1010, and the hindrance effect increases with the increase of the concentration of ether-based TPU. Both pure PA1010 and PA1010/ether-based TPU blends exhibit double melting peaks in the process of nonisothermal crystallization. The double melting peaks change differently with the variation of cooling rate and blend composition. The cooling rate only influences the lower melting peak; however, the blend composition influences not only the lower melting peak but also the higher melting peak. The reason for the phenomenon must be the interaction between the two compositions.

  8. Antimutagenic effect of crown ethers on heavy metal-induced sister chromatid exchanges.

    Science.gov (United States)

    Cai, M Y; Arenaz, P

    1998-01-01

    Macrocyclic polyethers (crown ethers) are a family of compounds that possess the ability to complex with and transport metal ions across membranes. Because of their unique ionophoric characteristic, they have wide application in industry and research, chemistry and biology. In the current investigation the relationship between heavy metal mutagenesis and crown ether co-mutagenicity and/or antimutagenicity in mammalian cells has been examined using sister chromatid exchange (SCE) as the cytogenetic end point. Chinese hamster ovary cells were treated with lead or cadmium, with and without selected crown ethers. Several genotoxic end points, including SCEs were scored and statistically compared. We report here that most of the crown ethers studied had little or no influence on lead- or cadmium-induced SCEs or chromosome aberrations. On the other hand, the substituted crown ether dicyclohexyl 21-crown-7 significantly decreased both spontaneous and metal-induced SCE frequencies, suggesting that this crown ether may possess antimutagenic activity.

  9. The Wireless Gateway Design of the Industrial Ethernet EtherCAT Network%工业以太网EtherCAT的无线网关设计

    Institute of Scientific and Technical Information of China (English)

    魏亚鹏; 韩卫光

    2013-01-01

    The Real-time Ethernet technology is a hot issue in the industrial communication area,and the EtherCAT technology has a bright prospect in such field.The wireless sensor network ZigBee technology can bring forth the convenience of the transmission channel on the deployment and planning,which can reduce many costs and troubles of the network cabling construction.Making a gateway which connects the EtherCAT network with the ZigBee network can expand the range of the industrial communication networks.In this way,the EtherCAT master can achieve a perception of the change in the industrial manufacturing environment.On the basis of further study on these two protocols,an implementation scheme of ZigBee accessing EtherCAT is proposed,and a communication model of an EtherCAT-ZigBee gateway is designed,and the gateway which connects the EtherCAT network and the ZigBee network is designed and realized through using ARM Cortex-A8 and CC2530.After tests,it shows that the EtherCAT network and the ZigBee network can communicate with each other through the gateway,which is able to meet the needs of real-time collection of field data.%实时工业以太网技术是目前工业通信领域研究的热点,EtherCAT技术具有光明的应用前景.无线传感网ZigBee技术可以带来传输通道部署和规划上的便利,可以减少大量布线施工的代价与困扰.开发连接EtherCAT和ZigBee的网关可以拓展工业通信网络的范围,实现对工业制造现场的环境变化的感知.在对两种协议深入研究的基础上,提出了ZigBee接入EtherCAT的实现方案,设计了EtherCAT和ZigBee的网关通信模型,并且采用ARM Cortex-A8和CC2530设计并实现了连接EtherCAT与ZigBee的网关.经过测试表明,该网关实现了EtherCAT与ZigBee网络通信的协议转换功能,能够满足实时采集现场数据的需要.

  10. Thermodynamics of Hydrogen Production from Dimethyl Ether Steam Reforming and Hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    T.A. Semelsberger

    2004-10-01

    The thermodynamic analyses of producing a hydrogen-rich fuel-cell feed from the process of dimethyl ether (DME) steam reforming were investigated as a function of steam-to-carbon ratio (0-4), temperature (100 C-600 C), pressure (1-5 atm), and product species: acetylene, ethanol, methanol, ethylene, methyl-ethyl ether, formaldehyde, formic acid, acetone, n-propanol, ethane and isopropyl alcohol. Results of the thermodynamic processing of dimethyl ether with steam indicate the complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide for temperatures greater than 200 C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure (P = 1 atm). Increasing the operating pressure was observed to shift the equilibrium toward the reactants; increasing the pressure from 1 atm to 5 atm decreased the conversion of dimethyl ether from 99.5% to 76.2%. The order of thermodynamically stable products in decreasing mole fraction was methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol--formaldehyde, formic acid, and acetylene were not observed. The optimal processing conditions for dimethyl ether steam reforming occurred at a steam-to-carbon ratio of 1.5, a pressure of 1 atm, and a temperature of 200 C. Modeling the thermodynamics of dimethyl ether hydrolysis (with methanol as the only product considered), the equilibrium conversion of dimethyl ether is limited. The equilibrium conversion was observed to increase with temperature and steam-to-carbon ratio, resulting in a maximum dimethyl ether conversion of approximately 68% at a steam-to-carbon ratio of 4.5 and a processing temperature of 600 C. Thermodynamically, dimethyl ether processed with steam can produce hydrogen-rich fuel-cell feeds--with hydrogen concentrations exceeding 70%. This substantiates dimethyl ether as a viable source of hydrogen for PEM fuel cells.

  11. Integrated catalytic and electrocatalytic conversion of substituted phenols and diaryl ethers

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yang; Chia, Shao H.; Sanyal, Udishnu; Gutierrez, Oliver Y.; Lercher, Johannes A.

    2016-10-17

    Electrocatalytic hydrogenation and catalytic thermal hydrogenation of substituted phenols and diaryl ethers were studied on carbon-supported Rh. For electrocatalytic and catalytic thermal hydrogen addition reactions, the dominant reaction pathway is hydrogenation to cyclic alcohols and cycloalkyl ethers. The presence of substituting methyl or methoxy groups led to lower rates compared to unsubstituted phenol or diphenyl ether. Methoxy or benzyloxy groups, however, undergo C-O bond cleavage via hydrogenolysis and hydrolysis (minor pathway).

  12. An investigation into pharmaceutically relevant mutagenicity data and the influence on Ames predictive potential

    Directory of Open Access Journals (Sweden)

    McCarren Patrick

    2011-11-01

    Full Text Available Abstract Background In drug discovery, a positive Ames test for bacterial mutation presents a significant hurdle to advancing a drug to clinical trials. In a previous paper, we discussed success in predicting the genotoxicity of reagent-sized aryl-amines (ArNH2, a structure frequently found in marketed drugs and in drug discovery, using quantum mechanics calculations of the energy required to generate the DNA-reactive nitrenium intermediate (ArNH:+. In this paper we approach the question of what molecular descriptors could improve these predictions and whether external data sets are appropriate for further training. Results In trying to extend and improve this model beyond this quantum mechanical reaction energy, we faced considerable difficulty, which was surprising considering the long history and success of QSAR model development for this test. Other quantum mechanics descriptors were compared to this reaction energy including AM1 semi-empirical orbital energies, nitrenium formation with alternative leaving groups, nitrenium charge, and aryl-amine anion formation energy. Nitrenium formation energy, regardless of the starting species, was found to be the most useful single descriptor. External sets used in other QSAR investigations did not present the same difficulty using the same methods and descriptors. When considering all substructures rather than just aryl-amines, we also noted a significantly lower performance for the Novartis set. The performance gap between Novartis and external sets persists across different descriptors and learning methods. The profiles of the Novartis and external data are significantly different both in aryl-amines and considering all substructures. The Novartis and external data sets are easily separated in an unsupervised clustering using chemical fingerprints. The chemical differences are discussed and visualized using Kohonen Self-Organizing Maps trained on chemical fingerprints, mutagenic substructure

  13. AME survey-003 A1-part 2: the motivation factors of medical doctors in China.

    Science.gov (United States)

    Wáng, Yì-Xiáng J; Káplár, Zoltán; L, Yáo T

    2015-12-01

    The professional moral and job satisfaction of medical profession remain highly disputed in media in China. On the other hand, there is wide disaffection of patients toward doctors in China. This survey aims to obtain a better understanding of the motivation of Chinese medical professionals. An anonymous online cross-sectional survey, AME survey III, was conducted using the platform provided by DXY (www.dxy.cn) during the period of September 10-23, 2015. In total 2,356 DXY users completed the survey, including 1,740 males and 617 females, with a mean age of 31.96±7.03 yrs. The reasons (multiple choices) for career disaffection included poor patient/doctor relationship (88.6%), imbalance between workload and pay (79.5%), could not enter the preferred specialty (14.14%), and working in small clinics with no career progress (11.17%). If given the choice to enter the specialty as well as the hospital grade of their choice, 73.8% dissatisfied respondents replied they would like to be a doctor. For the dis-satisfied respondents, university teacher appeared to be the most popular career choice. The cited high workload was considered to be due to (I) imbalance in geographical allocation of doctors and insufficient training of doctors; (II) many red-tapism formalities; (III) Chinese patients often have unreasonable requests; (IV) over-examination and over-treatment; (V) high pressure to publish papers. One hundred and twelve respondents have their child/children attending university or graduated from university, 25.0% of them are pursuing a career in medicine. Nine hundred and ninety respondents have child/children while did not reach university age yet, among them 23.62% would like their child/children to study medicine. 64.87% of the 2,356 participants favor China to open up medical market to qualified foreign medical organizations to take part in fair competition, and 57.91% favor the government supporting regulated private hospitals. The moral and motivation of medical

  14. AMEE Guide 32: e-Learning in medical education Part 1: Learning, teaching and assessment.

    Science.gov (United States)

    Ellaway, Rachel; Masters, Ken

    2008-06-01

    In just a few years, e-learning has become part of the mainstream in medical education. While e-learning means many things to many people, at its heart it is concerned with the educational uses of technology. For the purposes of this guide, we consider the many ways that the information revolution has affected and remediated the practice of healthcare teaching and learning. Deploying new technologies usually introduces tensions, and e-learning is no exception. Some wish to use it merely to perform pre-existing activities more efficiently or faster. Others pursue new ways of thinking and working that the use of such technology affords them. Simultaneously, while education, not technology, is the prime goal (and for healthcare, better patient outcomes), we are also aware that we cannot always predict outcomes. Sometimes, we have to take risks, and 'see what happens.' Serendipity often adds to the excitement of teaching. It certainly adds to the excitement of learning. The use of technology in support of education is not, therefore, a causal or engineered set of practices; rather, it requires creativity and adaptability in response to the specific and changing contexts in which it is used. Medical Education, as with most fields, is grappling with these tensions; the AMEE Guide to e-Learning in Medical Education hopes to help the reader, whether novice or expert, navigate them. This Guide is presented both as an introduction to the novice, and as a resource to more experienced practitioners. It covers a wide range of topics, some in broad outline, and others in more detail. Each section is concluded with a brief 'Take Home Message' which serves as a short summary of the section. The Guide is divided into two parts. The first part introduces the basic concepts of e-learning, e-teaching, and e-assessment, and then focuses on the day-to-day issues of e-learning, looking both at theoretical concepts and practical implementation issues. The second part examines technical

  15. Growth hormone abolishes beneficial effects of calorie restriction in long-lived Ames dwarf mice.

    Science.gov (United States)

    Gesing, Adam; Al-Regaiey, Khalid A; Bartke, Andrzej; Masternak, Michal M

    2014-10-01

    Disruption of the growth hormone (GH) axis promotes longevity and delays aging. In contrast, GH over-expression may lead to accelerated aging and shorter life. Calorie restriction (CR) improves insulin sensitivity and may extend lifespan. Long-lived Ames dwarf (df/df) mice have additional extension of longevity when subjected to 30% CR. The aim of the study was to assess effects of CR or GH replacement therapy separately and as a combined (CR+GH) treatment in GH-deficient df/df and normal mice, on selected metabolic parameters (e.g., insulin, glucose, cholesterol), insulin signaling components (e.g., insulin receptor [IR] β-subunit, phosphorylated form of IR [IR pY1158], protein kinase C ζ/λ [p-PKCζ/λ] and mTOR [p-mTOR]), transcription factor p-CREB, and components of the mitogen-activated protein kinase (MAPK) signaling (p-ERK1/2, p-p38), responsible for cell proliferation, differentiation and survival. CR decreased plasma levels of insulin, glucose, cholesterol and leptin, and increased hepatic IR β-subunit and IR pY1158 levels as well as IR, IRS-1 and GLUT-2 gene expression compared to ad libitum feeding, showing a significant beneficial diet intervention effect. Moreover, hepatic protein levels of p-PKCζ/λ, p-mTOR and p-p38 decreased, and p-CREB increased in CR mice. On the contrary, GH increased levels of glucose, cholesterol and leptin in plasma, and p-mTOR or p-p38 in livers, and decreased plasma adiponectin and hepatic IR β-subunit compared to saline treatment. There were no GH effects on adiponectin in N mice. Moreover, GH replacement therapy did not affect IR, IRS-1 and GLUT-2 gene expression. GH treatment abolishes the beneficial effects of CR; it may suggest an important role of GH-IGF1 axis in mediating the CR action. Suppressed somatotrophic signaling seems to predominate over GH replacement therapy in the context of the examined parameters and signaling pathways.

  16. Recent Progress in Planetary Laboratory Astrophysics achieved with NASA Ames' COSmIC Facility

    Science.gov (United States)

    Salama, Farid; Sciamma-O'Brien, Ella; Bejaoui, Salma

    2016-10-01

    We describe the characteristics and the capabilities of the laboratory facility, COSmIC, that was developed at NASA Ames to generate, process and analyze interstellar, circumstellar and planetary analogs in the laboratory [1]. COSmIC stands for "Cosmic Simulation Chamber" and is dedicated to the study of neutral and ionized molecules and nanoparticles under the low temperature and high vacuum conditions that are required to simulate various space environments such as planetary atmospheres. COSmIC integrates a variety of state-of-the-art instruments that allow forming, processing and monitoring simulated space conditions for planetary, circumstellar and interstellar materials in the laboratory. The COSmIC experimental setup is composed of a Pulsed Discharge Nozzle (PDN) expansion, that generates a plasma in the stream of a free supersonic jet expansion, coupled to two high-sensitivity, complementary in situ diagnostics: a Cavity Ring Down Spectroscopy (CRDS) and laser induced fluorescence (LIF) systems for photonic detection [2, 3], and a Reflectron Time-Of-Flight Mass Spectrometer (ReTOF-MS) for mass detection [4].Recent results obtained using COSmIC will be highlighted. In particular, the progress that has been achieved in an on-going study investigating the formation and the characterization of laboratory analogs of Titan's aerosols generated from gas-phase molecular precursors [5] will be presented. Plans for future laboratory experiments on planetary molecules and aerosols in the growing field of planetary laboratory astrophysics will also be addressed, as well as the implications of studies underway for astronomical observations.References: [1] Salama F., in Organic Matter in Space, IAU S251, Kwok & Sandford eds, CUP, S251, 4, 357 (2008).[2] Biennier L., Salama, F., Allamandola L., & Scherer J., J. Chem. Phys., 118, 7863 (2003)[3] Tan X, & Salama F., J. Chem. Phys. 122, 84318 (2005)[4] Ricketts C., Contreras C., Walker, R., Salama F., Int. J. Mass Spec, 300

  17. EtherCAT主导运动控制通信技术

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    日前,40个厂商准备或已宣布将EtherCAT伺服驱动产品推向市场。厂商们表明EtherCAT在运动控制领域已成为主导的通信技术。2008年纽伦堡SPS/IPC/Drives展会上,ETG展台证明了EtherCAT技术的成功。高性能、低成本和灵活的拓扑结构是众多伺服厂商及用户选择EtherCAT技术的根本原因。

  18. Synthesis and characterization of quaternized poly(phthalazinone ether sulfone ketone) for anion-exchange membrane

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Chloromethylated poly(phthalazinone ether sulfone ketone) (CMPPESK) was prepared from poly(phthalazinone ether sulfone ketone) (PPESK) using chloromethyl octyl ethers (CMOE) with lower toxicity as chloromethylated regent. CMPPESK was soluble in N-methyl-2-pyrrolidone (NMP), N,N-dimethylacetamide (DMAc) and chloroform. Quatemized poly(phthalazinone ether sulfone ketone) (QAPPESK) was prepared from CMPPESK by quaternization. QAPPESK had excellent solvent resistance,which was only partly soluble in sulfuric acid (98%) and swollen in N,N-dimethylformamide (DMF). The vanadium redox flow battery (V-RFB) using QAPPESK anion-exchange membrane had better performance with 88.3% of overall energy efficiency.

  19. AIRBORNE POLYBROMINATED DIPHENYL ETHERS IN A COMPUTER CLASSROOM OF COLLEGE IN TAIWAN

    Directory of Open Access Journals (Sweden)

    F. H. Chang ، C. R. Yang ، C. Y. Tsai ، W. C. Lin

    2009-04-01

    Full Text Available This study characterized the airborne exposure of students to thirty polybrominated diphenyl ether congeners inside and outside a computer classroom in a southern Taiwan college. Arithmetic mean values of total indoor and outdoor polybrominated diphenyl ether concentrations were 125.0 pg/m3 (89.8 to 203.9 pg/m3 and 110.3 pg/m3 (83.5 to 157.0 pg/m3, respectively. Total indoor polybrominated diphenyl ether concentrations were one order of magnitude lower than those detected in homes in Birmingham, United Kingdom and in Ottawa, Canada but were several times higher than those measured in the ambient air in Ottawa, Canada and from the Bohai Sea to the Arctic. The five highest indoor concentrations of polybrominated diphenyl ether congeners were decabromodiphenyl ether (23.0 pg/m3, 4,4’-dibromodiphenyl ether (15.9 pg/m3, 2,2’,3,4,4’,5,5’,6-octabromodiphenyl ether (10.6 pg/m3, 2,4-dibromodiphenyl ether (10.3 pg/m3 and 2,2’,3,4,4’,5’,6-heptabromodiphenyl ether (10.0 pg/m3. Although indoor and outdoor total polybrominated diphenyl ether concentrations did not significantly differ, the indoor concentrations of 2,4-dibromodiphenyl ether, 2,2’,4-tribromodiphenyl ether, 2,4,4’-tribromodiphenyl ether, 2,2’,4,5’-tetrabromodiphenyl ether and 2,3’,4’,6-tetrabromodiphenyl ether were significantly higher than their outdoor concentrations. This study suggests the following measures: 1 to increase the air exchange rate and open classroom doors and windows for several minutes before classes to reduce indoor PBDE concentrations; 2 to reduce polybrominated diphenyl ether emissions from new devices, it’s better to use computer-related products that meet the Restriction of Hazardous Substances Directive adopted by the European Union.

  20. Oxidation of ethyl ether on borate glass: chemiluminescence, mechanism, and development of a sensitive gas sensor.

    Science.gov (United States)

    Hu, Jing; Xu, Kailai; Jia, Yunzhen; Lv, Yi; Li, Yubao; Hou, Xiandeng

    2008-11-01

    A gas sensor was developed by using the chemiluminescence (CL) emission from the oxidation of ethyl ether by oxygen in the air on the surface of borate glass. Theoretical calculation, together with experimental investigation, revealed the main CL reactions: ethyl ether is first oxidized to acetaldehyde and then to acetic acid, during which main luminous intermediates such as CH 3CO (*) are generated and emit light with a peak at 493 nm. At a reaction temperature of 245 degrees C, the overall maximal emission was found at around 460 nm, and the linear range of the CL intensity versus the concentration of ethyl ether was 0.12-51.7 microg mL (-1) ( R = 0.999, n = 7) with a limit of detection (3sigma) of 0.04 microg mL (-1). Interference from foreign substances including alcohol (methanol, ethanol and isopropanol), acetone, ethyl acetate, n-hexane, cyclohexane, dichloromethane, or ether ( n-butyl ether, tetrahydrofuran, propylene oxide, isopropyl ether and methyl tert-butyl ether) was not significant except a minimal signal from n-butyl ether (ethyl ether.

  1. Glatiramer Acetate, Dimethyl Fumarate and Monomethyl Fumarate Up-Regulate the Expression of CCR10 on the Surface of Natural Killer Cells and Enhance their Chemotaxis and Cytotoxicity. Implications for Cancer Immunotherapy

    Directory of Open Access Journals (Sweden)

    Azzam Maghazachi

    2016-10-01

    Full Text Available In vitro harnessing of immune cells is the most important advance in the field of cancer immunotherapy. Results shown in the current paper may be used to harness natural killer (NK cells in vitro. It is observed that drugs used to treat multiple sclerosis such as glatiramer acetate, dimethyl fumarate and monomethyl fumarate up-regulate the expression of chemokines receptor 10 (CCR10 on the surface of human IL-2-activated NK cells. This is corroborated with increased chemotaxis of these cells towards the concentration gradients of the ligands for CCR10, namely CCL27 and CCL28. It is also demonstrated that these three drugs enhance NK cell cytotoxicity against tumor target cells, an activity that is abrogated by prior incubation of the cells with anti-CCR10 antibody. Because CCL27 and CCL28 are secreted by selective tumor types such as malignant melanoma, squamous cell carcinomas and colorectal cancer, respectively, it is hypothesized that activated NK cells may be harnessed in vitro with any of these drugs before utilizing them as a therapeutic modality for cancer.

  2. Reliability Analysis of Mine Monitoring Network Based on Ether CAT%EtherCAT井下监控网络可靠性分析研究

    Institute of Scientific and Technical Information of China (English)

    王玉梅; 张国治

    2015-01-01

    为进一步推动EtherCAT实时以太网技术在井下监控系统的应用并探寻最适宜井下实际情况、同时可靠性也最高的EtherCAT监控网络,首先通过对EtherCAT和ESC通讯技术的研究,并结合井下配电系统的实际情况,提出了EtherCAT有分站和无分站两种不同的井下监控网络,然后通过EtherCAT冗余网络可靠度计算的方法,分别对EtherCAT有分站和无分站两种监控网络可靠度进行了详细地分析、计算,并对两种监控网络可靠度的计算结果进行了对比论证,结果表明:EtherCAT无分站井下监控网络可靠性更高,可推广应用.

  3. Mutagenicity of automobile workshop soil leachate and tobacco industry wastewater using the Ames Salmonella fluctuation and the SOS chromotests.

    Science.gov (United States)

    Okunola, Alabi A; Babatunde, Esan E; Chinwe, Duru; Pelumi, Oyedele; Ramatu, Salihu G

    2016-06-01

    Environmental management of industrial solid wastes and wastewater is an important economic and environmental health problem globally. This study evaluated the mutagenic potential of automobile workshop soil-simulated leachate and tobacco wastewater using the SOS chromotest on Escherichia coli PQ37 and the Ames Salmonella fluctuation test on Salmonella typhimurium strains TA98 and TA100 without metabolic activation. Physicochemical parameters of the samples were also analyzed. The result of the Ames test showed mutagenicity of the test samples. However, the TA100 was the more responsive strain for both the simulated leachate and tobacco wastewater in terms of mutagenic index in the absence of metabolic activation. The SOS chromotest results were in agreement with those of the Ames Salmonella fluctuation test. Nevertheless, the E. coli PQ37 system was slightly more sensitive than the Salmonella assay for detecting genotoxins in the tested samples. Iron, cadmium, manganese, copper, nickel, chromium, arsenic, zinc, and lead contents analyzed in the samples were believed to play significant role in the observed mutagenicity in the microbial assays. The results of this study showed that the simulated leachate and tobacco wastewater showed strong indication of a genotoxic risk. Further studies would be required in the analytical field in order to identify and quantify other compounds not analyzed for in this study, some of which could be responsible for the observed genotoxicity. This will be necessary in order to identify the sources of toxicants and thus to take preventive and/or curative measures to limit the toxicity of these types of wastes. © The Author(s) 2014.

  4. ELAPSE - NASA AMES LISP AND ADA BENCHMARK SUITE: EFFICIENCY OF LISP AND ADA PROCESSING - A SYSTEM EVALUATION

    Science.gov (United States)

    Davis, G. J.

    1994-01-01

    One area of research of the Information Sciences Division at NASA Ames Research Center is devoted to the analysis and enhancement of processors and advanced computer architectures, specifically in support of automation and robotic systems. To compare systems' abilities to efficiently process Lisp and Ada, scientists at Ames Research Center have developed a suite of non-parallel benchmarks called ELAPSE. The benchmark suite was designed to test a single computer's efficiency as well as alternate machine comparisons on Lisp, and/or Ada languages. ELAPSE tests the efficiency with which a machine can execute the various routines in each environment. The sample routines are based on numeric and symbolic manipulations and include two-dimensional fast Fourier transformations, Cholesky decomposition and substitution, Gaussian elimination, high-level data processing, and symbol-list references. Also included is a routine based on a Bayesian classification program sorting data into optimized groups. The ELAPSE benchmarks are available for any computer with a validated Ada compiler and/or Common Lisp system. Of the 18 routines that comprise ELAPSE, provided within this package are 14 developed or translated at Ames. The others are readily available through literature. The benchmark that requires the most memory is CHOLESKY.ADA. Under VAX/VMS, CHOLESKY.ADA requires 760K of main memory. ELAPSE is available on either two 5.25 inch 360K MS-DOS format diskettes (standard distribution) or a 9-track 1600 BPI ASCII CARD IMAGE format magnetic tape. The contents of the diskettes are compressed using the PKWARE archiving tools. The utility to unarchive the files, PKUNZIP.EXE, is included. The ELAPSE benchmarks were written in 1990. VAX and VMS are trademarks of Digital Equipment Corporation. MS-DOS is a registered trademark of Microsoft Corporation.

  5. 工业以太网EtherCAT技术的原理及其实现%The principle of Industry Ethernet-EtherCAT and its implementation

    Institute of Scientific and Technical Information of China (English)

    王维建

    2010-01-01

    工业以太网技术是工业控制行业中的研究热点.EtherCAT技术以其高速、简单、易于实现正在获得越来越多的研发人员的关注.本文详细介绍了EtherCAT技术的原理和协议形式,并结合TMS320LF2407给出了一种具体的EtherCAT从站实现方式.

  6. Office of Health and Environmental Research. Quarterly report, April 1, 1979-June 30, 1979. [Ames Municipal Solid Waste Recovery System

    Energy Technology Data Exchange (ETDEWEB)

    Fassel, V.A.

    1979-10-01

    Progress in the following areas of research reported: characterization of organic pollutants emitted by fossil fuel processing and energy generating plants; environmental effects of using municipal solid wastes as a supplementary fuel; microbiological air quality at the Ames Municipal Solid Waste Recovery System; solid waste to methane environmental study; x-ray and ultraviolet excited optical luminescence (SEOL, UVEOL) of carcinogens - analytical possibilities; laser pumped luminescence (LPL) spectroscopy; and multielement characterization of air particulates. New laser-based methods for the determination of organic pollutants via fluorescence are discussed. (JGB)

  7. 2015 Review on the Extension of the AMedP-8(C) Methodology to New Agents, Materials, and Conditions

    Science.gov (United States)

    2016-06-01

    I N S T I T U T E F O R D E F E N S E A N A L Y S E S 2015 Review on the Extension of the AMedP-8(C) Methodology to New Agents, Materials, and... Methodology to New Agents, Materials, and Conditions Carl A. Curling Mark E. Bohannon This page is intentionally blank. iii Executive Summary In...Treaty Organization (NATO) planning guide documenting a methodology to estimate casualties from chemical, biological, radiological, and nuclear (CBRN

  8. Study of optical techniques for the Ames unitary wind tunnels. Part 2: Light sheet and vapor screen

    Science.gov (United States)

    Lee, George

    1992-01-01

    Light sheet and vapor screen methods have been studied with particular emphasis on those systems that have been used in large transonic and supersonic wind tunnels. The various fluids and solids used as tracers or light scatters and the methods for tracing generation have been studied. Light sources from high intensity lamps and various lasers have been surveyed. Light sheet generation and projection methods were considered. Detectors and location of detectors were briefly studied. A vapor screen system and a technique for location injection of tracers for the NASA Ames 9 by 7 foot Supersonic Wind Tunnel were proposed.

  9. NASA Ames's electric arc-driven shock tube facility and research on nonequilibrium phenomena in low density hypersonic flows

    Science.gov (United States)

    Sharma, Surendra P.

    1992-01-01

    Basic requirements for a ground test facility simulating low density hypersonic flows are discussed. Such facilities should be able to produce shock velocities in the range of 10-17 km/sec in an initial pressure of 0.010 to 0.050 Torr. The facility should be equipped with diagnostics systems to be able to measure the emitted radiation, characteristic temperatures and populations in various energy levels. In the light of these requirements, NASA Ames's electric arc-driven low density shock tube facility is described and available experimental diagnostics systems and computational tools are discussed.

  10. Freeze-out configuration properties in the 197Au + 197Au reaction at 23 AMeV

    CERN Document Server

    Najman, R; Sochocka, A; Amorini, F; Auditore, L; Cap, T; Cardella, G; De Filippo, E; Geraci, E; Grzeszczuk, A; Kowalski, S; Kozik, T; Lanzalone, G; Lombardo, I; Majka, Z; Nicolis, N G; Pagano, A; Piasecki, E; Pirrone, S; Politi, G; Rizzo, F; Russotto, P; Siwek-Wilczynska, K; Skwira-Chalot, I; Trifiro, A; Trimarchi, M; Wilczynski, J; Zipper, W

    2015-01-01

    Data from the experiment on the 197Au + 197Au reaction at 23 AMeV are analyzed with an aim to find signatures of exotic nuclear configurations such as toroid-shaped objects. The experimental data are compared with predictions of the ETNA code dedicated to look for such configurations and with the QMD model. A novel criterion of selecting events possibly resulting from the formation of exotic freeze-out configurations, "the efficiency factor", is tested. Comparison between experimental data and model predictions may indicate for the formation of flat/toroidal nuclear systems.

  11. Polybrominated diphenyl ethers (PBDEs): new pollutants-old diseases.

    Science.gov (United States)

    Siddiqi, Muhammad Akmal; Laessig, Ronald H; Reed, Kurt D

    2003-10-01

    Polybrominated diphenyl ethers (PBDEs) are a class of recalcitrant and bioaccumulative halogenated compounds that have emerged as a major environmental pollutant. PBDEs are used as a flame-retardant and are found in consumer goods such as electrical equipment, construction materials, coatings, textiles and polyurethane foam (furniture padding). Similar in structure to polychlorinated biphenyls (PCBs), PBDEs resist degradation in the environment. Less brominated PBDEs like tetra-, penta- and hexa- demonstrate high affinity for lipids and can accumulate in the bodies of animals and humans. Breast milk from North American women contained much higher amounts of PBDEs than levels in breast milk from Swedish women, indicating that North American exposures to PBDEs may be particularly high. Evidence to date suggests that tetra- and penta-BDEs are likely to be the more toxic and bioaccumulative of the PBDE compounds, compared to octa- and deca-congeners. PBDEs are sold as mixtures, under names such as "pentabromodiphenyl ether" and "octabromodiphenyl ether." The pentabromo product is a mixture of tetra-BDEs and penta-BDEs in approximately equal amounts. Pentabromo consists of PBDEs that are believed to be the most toxic. This mixture has been banned by the European Union, but is still used in North America. The United States is the leading producer and user of pentabromo. In August 2003, the State of California passed a bill to phase out the use of penta- and octa-PBDE by 2008. The toxicology of PBDEs is not well understood, but PBDEs have been associated with tumors, neurodevelopmental toxicity and thyroid hormone imbalance. The neurotoxic effects of PBDEs are similar to those observed for PCBs. Children exposed to PBDEs are prone to subtle but measurable developmental problems. It is presumed that PBDEs are endocrine disruptors, but research in this area is scant. Further studies are imperative in a multitude of health and environmental disciplines to determine the

  12. On the radiation stability of crown ethers in ionic liquids.

    Energy Technology Data Exchange (ETDEWEB)

    Shkrob, I.; Marin, T.; Dietz, M. (Chemical Sciences and Engineering Division); (Benedictine Univ.); (Univ. of Wisconsin at Milwaukee)

    2011-04-14

    Crown ethers (CEs) are macrocyclic ionophores used for the separation of strontium-90 from acidic nuclear waste streams. Room temperature ionic liquids (ILs) are presently being considered as replacements for traditional molecular solvents employed in such separations. It is desirable that the extraction efficacy obtained with such solvents should not deteriorate in the strong radiation fields generated by decaying radionuclides. This deterioration will depend on the extent of radiation damage to both the IL solvent and the CE solute. While radiation damage to ILs has been extensively studied, the issue of the radiation stability of crown ethers, particularly in an IL matrix, has not been adequately addressed. With this in mind, we have employed electron paramagnetic resonance (EPR) spectroscopy to study the formation of CE-related radicals in the radiolysis of selected CEs in ILs incorporating aromatic (imidazolium and pyridinium) cations. The crown ethers have been found to yield primarily hydrogen loss radicals, H atoms, and the formyl radical. In the low-dose regime, the relative yield of these radicals increases linearly with the mole fraction of the solute, suggesting negligible transfer of the excitation energy from the solvent to the solute; that is, the solvent has a 'radioprotective' effect. The damage to the CE in the loading region of practical interest is relatively low. Under such conditions, the main chemical pathway leading to decreased extraction performance is protonation of the macrocycle. At high radiation doses, sufficient to increase the acidity of the IL solvent significantly, such proton complexes compete with the solvent cations as electron traps. In this regime, the CEs will rapidly degrade as the result of H abstraction from the CE ring by the released H atoms. Thus, the radiation dose to which a CE/IL system is exposed must be maintained at a level sufficiently low to avoid this regime.

  13. Microbial degradation of 4-monobrominated diphenyl ether with anaerobic sludge

    Energy Technology Data Exchange (ETDEWEB)

    Shih, Yang-hsin, E-mail: yhs@ntu.edu.tw [Department of Agricultural Chemistry, National Taiwan University, Taipei 106, Taiwan, ROC (China); Chou, Hsi-Ling [Department of Soil and Environmental Sciences, National Chung Hsing University, Taichung 407, Taiwan, ROC (China); Peng, Yu-Huei [Department of Agricultural Chemistry, National Taiwan University, Taipei 106, Taiwan, ROC (China)

    2012-04-30

    Highlights: Black-Right-Pointing-Pointer BDE-3 was degraded with two anaerobes in different rates. Black-Right-Pointing-Pointer Glucose addition augment the debromination efficiencies. Black-Right-Pointing-Pointer Hydrogen gas was detected and relative microbes were identified. Black-Right-Pointing-Pointer Extra-carbon source enhanced degradation partial due to H{sub 2}-generation bacteria. - Abstract: Polybrominated diphenyl ethers (PBDEs) are widely used flame retardant additives for many plastic and electronic products. Owing to their ubiquitous distribution in the environment, multiple toxicity to humans, and increasing accumulation in the environment, the fate of PBDEs is of serious concern for public safety. In this study, the degradation of 4-monobrominated diphenyl ether (BDE-3) in anaerobic sludge and the effect of carbon source addition were investigated. BDE-3 can be degraded by two different anaerobic sludge samples. The by-products, diphenyl ether (DE) and bromide ions, were monitored, indicating the reaction of debromination within these anaerobic samples. Co-metabolism with glucose facilitated BDE-3 biodegradation in terms of kinetics and efficiency in the Jhongsing sludge. Through the pattern of amplified 16S rRNA gene fragments in denatured gradient gel electrophoresis (DGGE), the composition of the microbial community was analyzed. Most of the predominant microbes were novel species. The fragments enriched in BDE-3-degrading anaerobic sludge samples are presumably Clostridium sp. This enrichment coincides with the H{sub 2} gas generation and the facilitation of debromination during the degradation process. Findings of this study provide better understanding of the biodegradation of brominated DEs and can facilitate the prediction of the fate of PBDEs in the environment.

  14. CATALYSTS FOR HIGH CETANE ETHERS AS DIESEL FUELS

    Energy Technology Data Exchange (ETDEWEB)

    Kamil Klier; Richard G. Herman; Heock-Hoi Kwon; James G. C. Shen; Qisheng Ma; Robert A. Hunsicker; Andrew P. Butler; Scott J. Bollinger

    2003-03-01

    A tungstena-zirconia (WZ) catalyst has been investigated for coupling methanol and isobutanol to unsymmetrical ethers, i.e. methyl isobutyl ether (MIBE) and compared with earlier studied sulfated-zirconia (SZ) and Nafion-H catalysts. In all cases, the ether synthesis mechanism is a dual site S{sub N}2 process involving competitive adsorption of reactants on proximal acid sites. At low reaction temperatures, methylisobutylether (MIBE) is the predominant product. However, at temperatures >135 C the WZ catalyst is very good for dehydration of isobutanol to isobutene. The surface acid sites of the WZ catalyst and a Nafion-H catalyst were diagnosed by high resolution X-ray photoelectron spectroscopy (XPS) of N 1s shifts after adsorption of amines. Using pyridine, ethylenediamine, and triethylamine, it is shown that WZ has heterogeneous strong Broensted acid sites. Theoretical study located the transition state of the alcohol coupling reaction on proximal Broensted acid sites and accounted well for XPS core-level shifts upon surface acid-base interactions. While computations have not been carried out with WZ, it is shown that the SZ catalyst is a slightly stronger acid than CF{sub 3}SO{sub 3}H (a model for Nafion-H) by 1.3-1.4 kcal/mol. A novel sulfated zirconia catalyst having proximal strong Broensted acid sites was synthesized and shown to have significantly enhanced activity and high selectivity in producing MIBE or isobutene from methanol/isobutanol mixtures. The catalyst was prepared by anchoring 1,2-ethanediol bis(hydrogen sulfate) salt precursor onto zirconium hydroxide, followed by calcination to remove the -(CH{sub 2}CH{sub 2})- bridging residues.

  15. Green mechanochemical oxidative decomposition of powdery decabromodiphenyl ether with persulfate

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Aizhen; Zhang, Zhimin; Wang, Nan [College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zhu, Lihua, E-mail: lhzhu63@hust.edu.cn [College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zou, Jing [School of Chemistry and Environmental Engineering, Wuhan Institute of Technology, Wuhan 430073 (China)

    2016-01-25

    Highlights: • MC process greatly enhanced the decomposition of PS into reactive sulfate radicals. • The mechanochemical (MC) activation of persulfate was applied to degrade BDE209. • This method could achieve a rapid and complete debromination and mineralization of BDE209. • No toxic low brominated polybrominated diphenyl ethers were produced and accumulated. • Sulfate radicals were the main oxidizing species for the decomposition of BDE209. - Abstract: A method was developed for efficiently degrading powdery decabromodiphenyl ether (BDE209) by using mechanochemical (MC) activation of persulfate (PS). Characteristic Raman spectra of BDE209 corresponding to C−Br and C−O bonds were decreased in intensity and finally disappeared as the MC reaction proceeded. The BDE209 removal was influenced by the molar ratio of PS to BDE209, the mass ratio of milling ball to reaction mixtures, the ball size, and the ball rotation speed. Under optimal conditions, the new method could achieve a complete degradation, debromination and mineralization of BDE209 within 3 h of milling. However, the degradation removal (or debromination efficiency) was decreased to only 51.7% (15.6%) and 67.8% (31.5%) for the use of CaO and peroxymonosulfate, respectively. The analyses of products demonstrated that once the degradation was initiated, BDE209 molecules were deeply debrominated and fully mineralized in the MC-PS system. The strong oxidizing ability of this system was due to the reactive sulfate radicals generated from the MC-enhanced activation of PS, which was confirmed with electron spin resonance spectroscopy. Because no toxic low brominated polybrominated diphenyl ethers were accumulated as byproducts, the proposed MC oxidative degradation method will have promising applications in the treatment of solid BDE209 at high concentrations.

  16. EtherCAT技术协会精彩亮相

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    EtherCAT技术协会(ETG)携会员单位:德国倍福、欧姆龙、伦茨、科尔摩根、ACS、山洋电气、路斯特传动、TR、英国翠欧、瑞萨电子、顺德计算所、清能德创等12家国内外知名自动化厂商,以联合展台的形式精彩亮相SIAF2013。

  17. Degradation of β-Aryl Ether Bonds in Transgenic Plants

    DEFF Research Database (Denmark)

    Mnich, Ewelina

    of the monolignols coniferyl alcohol, p-coumaryl alcohol and sinapyl alcohol which during radical-mediated oxidative coupling bind together forming different linkage types. Lignin is the main obstacle in biofuel production as it forms a mechanical barrier limiting accessibility for polysaccharide hydrolyzing enzymes...... system to degrade lignin. An important step in this degradation is cleavage of the most abundant lignin linkage type, β-aryl ether. It is cleaved in a three step reaction catalyzed by a dehydrogenase, a glutathione S-transferase and a glutathione lyase. Due to the nature of the enzymatic reactions...

  18. Fluorescence properties of crown ethers with phenylbenzothiozole pendant group

    Science.gov (United States)

    Kapoor, S.; Sapre, A. V.; Kumar, S.; Mashraqui, S. H.; Mukherjee, T.

    2005-06-01

    Photophysical characteristics of 2-phenylbenzothiazole (PBT) substituted crown ether (CRE-PBT) molecules have been investigated in various polar protic solvents. Large Stokes' and good solvatochromic shifts have been observed for CRE-PBT molecules. It is seen that in these molecules, the fluorescence lifetimes and quantum yields increase as compared to the pristine PBT molecule. Temperature-dependence studies have been carried out to understand the effect of CRE substitution and the role of C-C single bond rotation on the fluorescence quantum yield and lifetime.

  19. Developments of Catalysts for Hydrogen Production from Dimethyl Ether

    Institute of Scientific and Technical Information of China (English)

    Kaoru; Takeishi

    2007-01-01

    1 Results Dimethyl ether (DME) is expected as a clean fuel of the 21st century.I have developed new catalysts for hydrogen production by steam reforming of DME.Cu-Zn/Al2O3 catalysts prepared by the sol-gel method produce large quantities of H2 and CO2 by DME steam reforming under lower reaction temperature[1].However,the sol-gel catalysts will be more expensive than general catalysts prepared by impregnation methods and coprecipitation methods,because the precursor,alkoxides are very expensive.For pract...

  20. Dimethyl ether production from methanol and/or syngas

    Energy Technology Data Exchange (ETDEWEB)

    Dagle, Robert A; Wang, Yong; Baker, Eddie G; Hu, Jianli

    2015-02-17

    Disclosed are methods for producing dimethyl ether (DME) from methanol and for producing DME directly from syngas, such as syngas from biomass. Also disclosed are apparatus for DME production. The disclosed processes generally function at higher temperatures with lower contact times and at lower pressures than conventional processes so as to produce higher DME yields than do conventional processes. Certain embodiments of the processes are carried out in reactors providing greater surface to volume ratios than the presently used DME reactors. Certain embodiments of the processes are carried out in systems comprising multiple microchannel reactors.

  1. Synthesis of dimethyl ether from methane mediated by HBr

    Institute of Scientific and Technical Information of China (English)

    Qin You; Zhen Liu; Wensheng Li; Xiaoping Zhou

    2009-01-01

    Dimethyl ether (DME) was synthesized from methane through a two-step process,in which CH_3 Br was prepared from the oxidative bromination reaction of methane in the presence of HBr and oxygen over a Rh-SiO_2 catalyst and then,in the second step,CH_3Br was hydrolyzed to DME over a silica supported metal chloride catalyst. 12 mol%ZnCl_2/SiO_2 catalyst was found to be the most active,but it deactivated because of Cl- losing.

  2. An aging study of wire chambers with dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Jibaly, M.; Chrusch, P. Jr.; Hilgenberg, G.; Majewski, S.; Wojcik, R.; Sauli, F.; Gaudaen, J.

    1989-02-01

    The authors report results on the aging of different types of resistive and non-resistive wires in wire chambers filled with dimethyl ether (DME) of varying degrees of purity. Among the Freon impurities detected in our DME batches, only Freon-11 was found to contribute to the aging process. Of the resistive wires, Nicotin and Stablohm produced fast aging, whereas stainless steel withstood extended irradiation in purified DME (up to 1 C/cm) without any apparent damage. Gold-plated tungsten and molybdenum wires produced results comparable to those of the stainless steel.

  3. Electrochemical Study of Diphenyl Ether Derivatives Used as Herbicides

    Directory of Open Access Journals (Sweden)

    Amira Zaouak

    2011-01-01

    Full Text Available The electrochemical behaviour of five nitro diphenyl ethers used as herbicides is investigated in acetonitrile. A detailed study by cyclic voltammetry and exhaustive electrolysis is carried out for the anodic oxidation of 2-Chloro-6-nitro-3-phenoxyaniline (aclonifen and shows that the major oxidation product is a dimeric compound. A mechanistic scheme involving a coupling process is postulated for the electrochemical oxidation of this compound. Furthermore, the use of differential pulse voltammetry on a glassy carbon electrode permits the selective determination of aclonifen. The limit of detection is 0.6 μg/mL.

  4. Direct dimethyl ether high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Vassiliev, Anton; Jensen, Jens Oluf; Li, Qingfeng

    and suffers from low DME solubility in water. When the DME - water mixture is fed as vapour miscibility is no longer a problem. The increased temperature is more beneficial for the kinetics of the direct oxidation of DME than of methanol. The Open Circuit Voltage (OCV) with DME operation was 50 to 100 m......A high temperature polybenzimidazole (PBI) polymer fuel cell was fed with dimethyl ether (DME) and water vapour mixture on the anode at ambient pressure with air as oxidant. A peak power density of 79 mW/cm2 was achieved at 200°C. A conventional polymer based direct DME fuel cell is liquid fed...

  5. Polybrominated diphenyl ethers (PBDEs) in house dust in Beijing, China.

    Science.gov (United States)

    Li, K; Fu, S

    2013-10-01

    Eleven house dust samples were collected in Beijing to quantify 42 different polybrominated diphenyl ethers (PBDEs). Total PBDEs concentrations ranged from 140 to 1,300 ng g(-1). The dominant PBDEs congener identified was BDE 209, which made up more than 70% of all PBDEs congeners. Concentrations of PBDEs in Chinese house dust were lower than in other countries. The most polluted areas were electronics shops and households. It is likely that PBDEs exposure is a potential threat for Beijing residents, particularly toddlers.

  6. Density measurements of compressed-liquid dimethyl ether + pentane mixtures.

    Science.gov (United States)

    Outcalt, Stephanie L; Lemmon, Eric W

    2016-01-01

    Compressed-liquid densities of three compositions of the binary mixture dimethyl ether (CAS No. 115-10-6) + pentane (CAS No. 109-66-0) have been measured with a vibrating U-tube densimeter. Measurements were made at temperatures from 270 K to 390 K with pressures from 1.0 MPa to 50 MPa. The overall combined uncertainty (k=2) of the density data is 0.81 kg·m(-3). Data presented here have been used to improve a previously formulated Helmholtz energy based mixture model. The newly derived parameters are given.

  7. Nucleophilic Addition of Organozinc Reagents to 2-Sulfonyl Cyclic Ethers

    Science.gov (United States)

    Kim, Hyoungsu; Kasper, Amanda C.; Moon, Eui Jung; Park, Yongho; Wooten, Ceshea M.; Dewhirst, Mark W.; Hong, Jiyong

    2009-01-01

    A convergent route to the synthesis of manassantins A and B, potent inhibitors of HIF-1, is described. Central to the synthesis is a stereoselective addition of an organozinc reagent to a 2-benzenesulfonyl cyclic ether to achieve the 2,3-cis-3,4-trans-4,5-cis-tetrahydrofuran of the natural products. Preliminary structure—activity relationships suggested that the (R)-configuration at C-7 and C-7″′ is not critical for HIF-1 inhibition. In addition, the hydroxyl group at C-7 and C-7″′ can be replaced with carbonyl group without loss of activity. PMID:19111058

  8. Synthesis and Characterization of a Novel Cellulose Nonionic Ether

    Institute of Scientific and Technical Information of China (English)

    SHAO Zi-qiang; XU Kun; TIAN Yong-sheng; WANG Fei-jun; WANG Ji-xun

    2005-01-01

    A kind of novel cellulose ether-trihydroxybutyl cellulose (THBC) was synthesized. The process includes the steam explosion treatment of cotton cellulose, alkalization, etherification and purification. Sweep electron microscope (SEM), Fourier transform infrared (FTIR) and X-ray diffraction were used to characterize the cellulose pretreated and the product. The effects of reaction conditions (temperature, time) on the molecular substitution (Sm) were discussed. To obtain a higher degree of molecular substitution, the reaction temperature is 80 ℃, and the reaction time is 4 h.

  9. Structure and Reactivity of Alkyl Ethers Adsorbed on CeO(2)(111) Model Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Calaza, Florencia C [ORNL; Chen, Tsung-Liang [ORNL; Mullins, David R [ORNL; Overbury, Steven {Steve} H [ORNL

    2011-01-01

    The effect of surface hydroxyls on the adsorption of ether on ceria was explored. Adsorption of dimethyl ether (DME) and diethyl ether (DEE) on oxidized and reduced CeO{sub 2}(111) films was studied and compared with Ru(0001) using RAIRS and sXPS within a UHV environment. On Ru(0001) the ethers adsorb weakly with the molecular plane close to parallel to the surface plane. On the ceria films, the adsorption of the ethers was stronger than on the metal surface, presumably due to stronger interaction of the ether oxygen lone pair electrons with a cerium cation. This interaction causes the ethers to tilt away from the surface plane compared to the Ru(0001) surface. No pronounced differences were found between oxidized (CeO{sub 2}) and reduced (CeOx) films. The adsorption of the ethers was found to be perturbed by the presence of OH groups on hydroxylated CeOx. In the case of DEE, the geometry of adsorption resembles that found on Ru, and in the case of dimethyl ether DME is in between that one found on clean CeOx and the metal surface. Decomposition of the DEE was observed on the OH/CeOx surface following high DEE exposure at 300 K and higher temperatures. Ethoxides and acetates were identified as adsorbed species on the surface by means of RAIRS and ethoxides and formates by s-XPS. No decomposition of dimethyl ether was observed on the OH/CeOx at these higher temperatures, implying that the dissociation of the C-O bond from ethers requires the presence of {beta}-hydrogen.

  10. Genotoxic evaluation of aspirin eugenol ester using the Ames test and the mouse bone marrow micronucleus assay.

    Science.gov (United States)

    Li, Jianyong; Kong, Xiaojun; Li, Xiwang; Yang, Yajun; Zhang, Jiyu

    2013-12-01

    Aspirin eugenol ester (AEE) is a promising drug candidate for treatment of inflammation, pain and fever and prevention of cardiovascular diseases with less side effects and it is important to characterize its genotoxicity. In this study, the genotoxicity of AEE was assessed with two standard genotoxicity assays of the Salmonella typhimurium mutagenicity assay (Ames test) and the mouse bone marrow micronucleus assay. In the Ames test, Salmonella strains TA97, TA98, TA100, TA102 and TA1535 were treated with or without the metabolic activation with a S9 fraction from Acroclor-induced rat liver. The doses of AEE were 5 mg/plate, 2.5 mg/plate, 1.25 mg/plate, 0.625 mg/plate and 0.3125 mg/plate, respectively. In the above tested strains, mutagenicity with or without the S-9 mixture was not detected. In the mammalian erythrocyte micronucleus assay, fifty mice were divided into five groups evenly and the AEE dose at 5000 mg/kg, 2500 mg/kg and 1250 mg/kg and the cyclophosphamide dose at 40 mg/kg as a positive control, the 0.5% of CMC-Na as negative control were administered. The results showed that AEE did not induce any significant increase in micronucleated erythrocytes after 24 h (p<0.01). Our results suggested that AEE was non-genotoxic in vivo or in vitro.

  11. Determination of mutagenicity and genotoxicity of indium tin oxide nanoparticles using the Ames test and micronucleus assay.

    Science.gov (United States)

    Akyıl, Dilek; Eren, Yasin; Konuk, Muhsin; Tepekozcan, Aykut; Sağlam, Esra

    2016-09-01

    In this study, the mutagenicity and genotoxicity of indium tin oxide (ITO) nanomaterial were assessed using two standard genotoxicity assays, the Salmonella reverse mutation assay (Ames test) and the in vitro micronucleus (MN) assay. Seven different concentrations (12.5, 25, 50, 75, 100, 125, and 150 µg/plate) of this nanomaterial were tested using the Ames test on the TA98 and TA100 strains in the presence and absence of the S9 mixture. At all the concentrations tested, this substance did not significantly increase the number of revertant colonies compared with the control with or without S9 mixture. The genotoxic effects of ITO were investigated in human peripheral lymphocytes treated with 125, 250, 500, and 750 µg/ml concentrations of this substance for 24- and 48-h treatment periods using an MN test. Nuclear division index (NDI) was also calculated in order to determine the cytotoxicity of ITO. It was determined that ITO increased MN frequency in the 750 µg/ml concentration in 24- and 48-h treatments. In addition, ITO dose dependently decreased the NDI significantly for two treatment periods.

  12. Measurement of 100 B. anthracis Ames spores within 15 minutes by SERS at the US Army Edgewood Chemical Biological Ctr.

    Science.gov (United States)

    Farquharson, Stuart; Shende, Chetan; Smith, Wayne; Huang, Hermes; Sperry, Jay; Sickler, Todd; Prugh, Amber; Guicheteau, Jason

    2014-05-01

    Since the distribution of Bacillus anthracis-Ames spores through the US Postal System, there has been a persistent fear that biological warfare agents will be used by terrorists against our military abroad and our civilians at home. While there has been substantial effort since the anthrax attack of 2001 to develop analyzers to detect this and other biological warfare agents, the analyzers remain either too slow, lack sensitivity, produce high false-positive rates, or cannot be fielded. In an effort to overcome these limitations we have been developing a surface-enhanced Raman spectroscopy system. Here we describe the use of silver nanoparticles functionalized with a short peptide to selectively capture Bacillus anthracis spores and produce SER scattering. Specifically, measurements of 100 B. anthracis-Ames spores/mL in ~25 minutes performed at the US Army's Edgewood Chemical Biological Center are presented. The measurements provide a basis for the development of systems that can detect spores collected from the air or water supplies with the potential of saving lives during a biological warfare attack.

  13. Genotoxicity evaluation of locally produced dental porcelain--an in vitro study using the Ames and Comet assays.

    Science.gov (United States)

    Noushad, Mohammed; Kannan, Thirumulu Ponnuraj; Husein, Adam; Abdullah, Haswati; Ismail, Abdul Rashid

    2009-09-01

    The aim of this study was to determine the genotoxicity of a locally produced dental porcelain (Universiti Sains Malaysia, Malaysia) using the Ames and Comet assays. In the Ames assay, four genotypic variants of the Salmonella strains (TA98, TA100, TA1537 and TA1535) carrying mutations in several genes were used. The dental porcelain was incubated with these four strains in five different doses both in the presence and absence of metabolic activation (S9) and the result was assessed based on the number of revertant colonies. Concurrently, appropriate positive controls were used so as to validate the test. The average number of revertant colonies per plate treated with locally produced dental porcelain was less than double as compared to that of negative control. In the Comet assay, L929 (CCL-1 ATCC, USA) mouse fibroblast cells were treated with the dental porcelain in three different concentrations along with concurrent negative and positive controls. The tail moment which was used as a measurement of DNA damage was almost equal to that of the negative control, suggesting that the locally produced dental porcelain did not induce any DNA damage. The results indicated that the locally produced dental porcelain is non-genotoxic under the present test conditions.

  14. In vitro mutagenicity assay (Ames test and phytochemical characterization of seeds oil of Helianthus annuus Linné (sunflower

    Directory of Open Access Journals (Sweden)

    Nelma de Mello Silva Oliveira

    2016-01-01

    Full Text Available The objective of this research was to investigate the genotoxic potential of the oil of H. annuus L. (sunflower seeds via the Ames test as well as its oxidative properties and lipid composition. The pre-incubation method, system metabolic activation (S9 fraction and five S. typhimurium strains (TA97, TA98, TA100, TA1535 and TA102 were employed for the Ames test. The oxidative stability and fatty acid composition were analyzed by standard methods and gas chromatography. A revertant analysis showed no significant differences between the treatment doses (10–200 μl/plate and the negative controls, regardless of S9+ and S9−, and included all of the S. typhimurium strains. Chromatographic analysis showed high levels of polyunsaturated fatty acids, followed by monounsaturated, saturated and total trans-isomers. Among the polyunsaturated, monounsaturated and saturated fatty acids, linoleic, oleic and palmitic acids predominated. The results suggest that the sunflower oil is not genotoxic as indicated by frameshift mutations and base pair substitutions regardless of the treatment dose, but shows dose-dependent toxicity. The oxidative properties of the sunflower oil were consistent with the requirements of national and international standards. However, its composition could also indicate phytotherapeutic properties.

  15. Sorption-desorption behavior of polybrominated diphenyl ethers in soils

    Energy Technology Data Exchange (ETDEWEB)

    Olshansky, Yaniv; Polubesova, Tamara [Department of Soil and Water Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100 (Israel); Vetter, Walter [Institute of Food Chemistry (170b), University of Hohenheim, Garbenstr. 28, D-70599 Stuttgart (Germany); Chefetz, Benny, E-mail: chefetz@agri.huji.ac.il [Department of Soil and Water Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100 (Israel)

    2011-10-15

    Polybrominated diphenyl ethers (PBDEs) are flame retardants that are commonly found in commercial and household products. These compounds are considered persistent organic pollutants. In this study, we used 4,4'-dibromodiphenyl ether (BDE-15) as a model compound to elucidate the sorption and desorption behavior of PBDEs in soils. The organic carbon-normalized sorption coefficient (K{sub OC}) of BDE-15 was more than three times higher for humin than for bulk soils. However, pronounced desorption hysteresis was obtained mainly for bulk soils. For humin, increasing concentration of sorbed BDE-15 resulted in decreased desorption. Our data illustrate that BDE-15 and probably other PBDEs exhibit high sorption affinity to soils. Moreover, sorption is irreversible and thus PBDEs can potentially accumulate in the topsoil layer. We also suggest that although humin is probably a major sorbent for PBDEs in soils, other humic materials are also responsible for their sequestration. - Highlights: > BDE-15 exhibited pronounced desorption hysteresis. > BDE-15 sowed higher sorption affinity to humin as compared to the bulk soils. > Sequestration of PBDEs depends on soil organic matter constitutes other than humin. - Pronounced desorption hysteresis was observed for BDE-15 in natural soils.

  16. Alkali-crown ether complexes at metal surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Thontasen, Nicha; Deng, Zhitao; Rauschenbach, Stephan [Max Planck Institute for Solid State Research, Stuttgart (Germany); Levita, Giacomo [University of Trieste, Trieste (Italy); Malinowski, Nikola [Max Planck Institute for Solid State Research, Stuttgart (Germany); Bulgarian Academy of Sciences, Sofia (Bulgaria); Kern, Klaus [Max Planck Institute for Solid State Research, Stuttgart (Germany); EPFL, Lausanne (Switzerland)

    2010-07-01

    Crown ethers are polycyclic ethers which, in solution, selectively bind cations depending on the size of the ring cavity. The study of a single host-guest complex is highly desirable in order to reveal the characteristics of these specific interactions at the atomic scale. Such detailed investigation is possible at the surface where high resolution imaging tools like scanning tunneling microscopy (STM) can be applied. Here, electrospray ion beam deposition (ES-IBD) is employed for the deposition of Dibenzo-24-crown-8 (DB24C8)-H{sup +}, -Na{sup +} and -Cs{sup +} complexes on a solid surface in ultrahigh vacuum (UHV). Where other deposition techniques have not been successful, this deposition technique combines the advantages of solution based preparation of the complex ions with a highly clean and controlled deposition in UHV. Single molecular structures and the cation-binding of DB24C8 at the surface are studied in situ by STM and MALDI-MS (matrix assisted laser desorption ionization mass spectrometry). The internal structure of the complex, i.e. ring and cavity, is observable only when alkali cations are incorporated. The BD24C8-H{sup +} complex in contrast appears as a compact feature. This result is in good agreement with theoretical models based on density functional theory calculations.

  17. High octane ethers from synthesis gas-derived alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Klier, K.; Herman, R.G.; DeTavernier, S.; Johannson, M.; Kieke, M.; Bastian, R.D.

    1991-07-01

    The temperature dependence of ether synthesis, particularly unsymmetric methylisobutylether (MIBE), was carried out over the Nafion-H microsaddles (MS) catalyst. The principal product formed under the rather severe reaction conditions of 1100 psig pressure and temperatures in the range of 123--157{degree}C was the expected MIBE formed directly by coupling the methanol/isobutanol reactants. In addition, significantly larger quantities of the dimethylether (DME) and hydrocarbon products were observed than were obtained under milder reaction conditions. Deactivation of the Nafion-H MS catalyst was determined by periodically testing the catalyst under a given set of reaction conditions for the synthesis of MIBE and MTBE from methanol/isobutanol = 2/1, i.e. 123{degree}C, 1100 psig, and total GHSV = 248 mol/kg cat/hr. After carrying out various tests over a period of 2420 hr, with intermittant periods of standing under nitrogen at ambient conditions, the yields of MIBE and MTBE had decreased by 25% and 41%, respectively. In order to gain insight into the role of the surface acidity in promoting the selective coupling of the alcohols to form the unsymmetric ether, the strengths of the acid sites on the catalysts are still being probed by calorimetric titrations in non-aqueous solutions. 11 refs., 13 figs., 9 tabs.

  18. Evaluating the Swelling, Erosion and Compaction Properties of Cellulose Ethers.

    Science.gov (United States)

    Ghori, Muhammad U; Grover, Liam M; Asare-Addo, Kofi; Smith, Alan M; Conway, Barbara R

    2017-10-06

    Swelling, erosion, deformation and consolidation properties can affect the performance of cellulose ethers, the most commonly used matrix former in hydrophilic sustained tablet formulations. The present study was designed to comparatively evaluate the swelling, erosion, compression, compaction and relaxation properties of the cellulose ethers in a comprehensive study using standardised conditions. The interrelationship between various compressional models and the inherent deformation and consolidation properties of the polymers on the derived swelling and erosion parameters are consolidated. The impact of swelling (Kw) on erosion rates (KE) and the inter-relationship between Heckel and Kawakita plasticity constants was also investigated. It is evident from the findings that the increases in both substitution and polymer chain length led to higher Kw, but a lower KE; this was also true for all particle size fractions regardless of polymer grade. Smaller particle size and high substitution levels tend to increase the relative density of the matrix but reduce porosity, yield pressure (Py), Kawakita plasticity parameter (b(-1)) and elastic relaxation. Both KW vs KE (R(2) = 0.949-0.980) and Py vs b(-1) correlations (R(2) = 0.820-0.934) were reasonably linear with regards to increasing hydroxypropyl substitution and molecular size. Hence, it can be concluded that the combined knowledge of swelling and erosion kinetics in tandem with the in and out-of-die compression findings can be used to select a specific polymer grade and further to develop and optimise formulations for oral controlled drug delivery applications.

  19. Developmental toxicity of diphenyl ether herbicides in nestling American kestrels

    Science.gov (United States)

    Hoffman, D.J.; Spann, J.W.; LeCaptain, L.J.; Bunck, C.M.; Rattner, B.A.

    1991-01-01

    Beginning the day after hatching, American kestrel (Falco sparverius) nestlings were orally dosed for 10 consecutive days with 5 microliters/g of corn oil (controls) or one of the diphenyl ether herbicides (nitrofen, bifenox, or oxyfluorfen) at concentrations of 10, 50, 250, or 500 mg/kg in corn oil. At 500 mg/kg, nitrofen resulted in complete nestling mortality, bifenox in high (66%) mortality, and oxyfluorfen in no mortality. Nitrofen at 250 mg/kg reduced nestling growth as reflected by decreased body weight, crownrump length, and bone lengths including humerus, radiusulna, femur, and tibiotarsus. Bifenox at 250 mg/kg had less effect on growth than nitrofen, but crownrump, humerus, radiusulna, and femur were significantly shorter than controls. Liver weight as a percent of body weight increased with 50 and 250 mg/kg nitrofen. Other manifestations of impending hepatotoxicity following nitrofen ingestion included increased hepatic GSH peroxidase activity in all nitrofentreated groups, and increased plasma enzyme activities for ALT, AST, and LDHL in the 250mg/kg group. Bifenox ingestion resulted in increased hepatic GSH peroxidase activity in the 50and 250mg/kg groups. Nitrofen exposure also resulted in an increase in total plasma thyroxine (T4) concentration. These findings suggest that altricial nestlings are more sensitive to diphenyl ether herbicides than young or adult birds of precocial species.

  20. Molecular dynamics simulations of ether- and ester-linked phospholipids.

    Science.gov (United States)

    Kruczek, James; Saunders, Matthew; Khosla, Meghna; Tu, Yicheng; Pandit, Sagar A

    2017-09-04

    Dissimilarities in the bulk structure of bilayers composed of ether- vs ester-linked lipids are well-established; however, the atomistic interactions responsible for these differences are not well known. These differences are important in understanding of why archaea have a different bilayer composition than the other domains of life and why humans have larger concentrations of plasmalogens in specialized membranes? In this paper, we simulate two lipid bilayers, the ester linked dipalmitoylphosphatidylcholine (DPPC) and the ether lined dihexadecylphosphatidylcholine (DHPC), to study these variations. The structural analysis of the bilayers reveals that DPPC is more compressible than DHPC. A closer examination of dipole potential shows DHPC, despite having a smaller dipole potential of the bilayer, has a higher potential barrier than DPPC at the surface. Analysis of water order and dynamics suggests DHPC has a more ordered, less mobile layer of water in the headgroup. These results seem to resolve the issue as to whether the decrease in permeability of DHPC is due to of differences in minimum area per lipid (A0) or diffusion coefficient of water in the headgroup region (Dhead) (Guler et al., 2009) since we have shown significant changes in the order and mobility of water in that region. Copyright © 2017 Elsevier B.V. All rights reserved.