Science.gov

Sample records for acid trihydrate nat

  1. Heterogeneous Formation of Polar Stratospheric Clouds- Part 1: Nucleation of Nitric Acid Trihydrate (NAT)

    NASA Technical Reports Server (NTRS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooss, J.-U.; Peter, T.

    2013-01-01

    Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid-December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled a thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed polar stratospheric clouds (PSCs) very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  2. Heterogeneous formation of polar stratospheric clouds - Part 1: Nucleation of nitric acid trihydrate (NAT)

    NASA Astrophysics Data System (ADS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooß, J.-U.; Peter, T.

    2013-09-01

    Satellite-based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid-December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarization (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled a thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed polar stratospheric clouds (PSCs) very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  3. Heterogeneous formation of polar stratospheric clouds - Part 1: Nucleation of nitric acid trihydrate (NAT)

    NASA Astrophysics Data System (ADS)

    Hoyle, C. R.; Engel, I.; Luo, B. P.; Pitts, M. C.; Poole, L. R.; Grooß, J.-U.; Peter, T.

    2013-03-01

    Satellite based observations during the Arctic winter of 2009/2010 provide firm evidence that, in contrast to the current understanding, the nucleation of nitric acid trihydrate (NAT) in the polar stratosphere does not only occur on preexisting ice particles. In order to explain the NAT clouds observed over the Arctic in mid December 2009, a heterogeneous nucleation mechanism is required, occurring via immersion freezing on the surface of solid particles, likely of meteoritic origin. For the first time, a detailed microphysical modelling of this NAT formation pathway has been carried out. Heterogeneous NAT formation was calculated along more than sixty thousand trajectories, ending at Cloud Aerosol Lidar with Orthogonal Polarisation (CALIOP) observation points. Comparing the optical properties of the modelled NAT with these observations enabled the thorough validation of a newly developed NAT nucleation parameterisation, which has been built into the Zurich Optical and Microphysical box Model (ZOMM). The parameterisation is based on active site theory, is simple to implement in models and provides substantial advantages over previous approaches which involved a constant rate of NAT nucleation in a given volume of air. It is shown that the new method is capable of reproducing observed PSCs very well, despite the varied conditions experienced by air parcels travelling along the different trajectories. In a companion paper, ZOMM is applied to a later period of the winter, when ice PSCs are also present, and it is shown that the observed PSCs are also represented extremely well under these conditions.

  4. Metastable Nitric Acid Trihydrate in Ice Clouds

    PubMed Central

    Weiss, Fabian; Kubel, Frank; Gálvez, Óscar; Hoelzel, Markus; Parker, Stewart F.; Baloh, Philipp; Iannarelli, Riccardo; Rossi, Michel J.

    2016-01-01

    Abstract The composition of high‐altitude ice clouds is still a matter of intense discussion. The constituents in question are ice and nitric acid hydrates, but the exact phase composition of clouds and its formation mechanisms are still unknown. In this work, conclusive evidence for a long‐predicted phase, alpha‐nitric acid trihydrate (alpha‐NAT), is presented. This phase was characterized by a combination of X‐ray and neutron diffraction experiments, allowing a convincing structure solution. Furthermore, vibrational spectra (infrared and inelastic neutron scattering) were recorded and compared with theoretical calculations. A strong interaction between water ice and alpha‐NAT was found, which explains the experimental spectra and the phase‐transition kinetics. On the basis of these results, we propose a new three‐step mechanism for NAT formation in high‐altitude ice clouds. PMID:26879259

  5. Metastable Nitric Acid Trihydrate in Ice Clouds.

    PubMed

    Weiss, Fabian; Kubel, Frank; Gálvez, Óscar; Hoelzel, Markus; Parker, Stewart F; Baloh, Philipp; Iannarelli, Riccardo; Rossi, Michel J; Grothe, Hinrich

    2016-03-01

    The composition of high-altitude ice clouds is still a matter of intense discussion. The constituents in question are ice and nitric acid hydrates, but the exact phase composition of clouds and its formation mechanisms are still unknown. In this work, conclusive evidence for a long-predicted phase, alpha-nitric acid trihydrate (alpha-NAT), is presented. This phase was characterized by a combination of X-ray and neutron diffraction experiments, allowing a convincing structure solution. Furthermore, vibrational spectra (infrared and inelastic neutron scattering) were recorded and compared with theoretical calculations. A strong interaction between water ice and alpha-NAT was found, which explains the experimental spectra and the phase-transition kinetics. On the basis of these results, we propose a new three-step mechanism for NAT formation in high-altitude ice clouds. PMID:26879259

  6. Metastable Nitric Acid Trihydrate in Ice Clouds

    NASA Astrophysics Data System (ADS)

    Weiss, Fabian; Kubel, Frank; Gálvez, Oscar; Hölzel, Markus; Parker, Stewart F.; Baloh, Philipp; Iannarelli, Riccardo; Rossi, Michel J.; Grothe, Hinrich

    2016-04-01

    The composition of high altitude ice clouds is still a matter of intense discussion. The constituents in question are ice and nitric acid hydrates. The identification and formation mechanisms, however, are still unknown but are essential to understand atmospheric processing such as the seasonal ozone depletion in the lower polar stratosphere or the radiation balance of planet Earth. We found conclusive evidence for a long-predicted phase, which has been named alpha nitric acid trihydrate (alpha-NAT). This phase has been proven by combination of X-ray and neutron diffraction experiments allowing a convincing structure solution. Additionally, vibrational spectra (infrared and inelastic neutron scattering) were recorded and compared with theoretical calculations. A strong affinity between water ice and alpha-NAT has been found, which explains the experimental spectra and the phase transition kinetics essential for identification in the atmosphere. On the basis of our results, we propose a new three-step mechanism for NAT-formation in high altitude ice clouds. F. Weiss et al. Angew. Chem. Int. Ed. 2016, accepted, DOI:10.1002/anie.201510841

  7. Dissolution of sulfuric acid tetrahydrate at low temperatures and subsequent growth of nitric acid trihydrate

    NASA Astrophysics Data System (ADS)

    Iraci, Laura T.; Fortin, Tara J.; Tolbert, Margaret A.

    1998-04-01

    Crystalline sulfuric acid tetrahydrate (SAT) has been observed to change phase at temperatures below its melting point, in agreement with recent theoretical predictions of deliquescence. Dissolution of SAT was observed in 63% of experiments expected to show a phase change, leading to formation of a ternary HNO3/H2SO4/H2O solution. This solution, which still contained a portion of the original solid SAT, crystallized to form nitric acid trihydrate (NAT). NAT then continued to grow by condensation of additional nitric acid and water at temperatures several degrees above the ice frost point. This process of SAT dissolution followed by NAT crystallization and growth may offer a mechanism for the formation of type Ia polar stratospheric clouds on frozen sulfate aerosols when SNAT>15.

  8. Heterogeneous reactions on nitric acid trihydrate. [on surfaces of polar stratospheric cloud particles

    NASA Technical Reports Server (NTRS)

    Moore, S. B.; Keyser, L. F.; Leu, M.-T.; Smith, R. H.; Turco, R. P.

    1990-01-01

    The first direct measurements are reported of the reaction probabilities at stratospheric temperatures for two important heterogeneous reactions on nitric acid trihydrate (NAT), the compound which makes up the predominant, type I form of polar stratospheric cloud (PSC). Sticking coefficients and solubilities of HCl and NAT, which are important in modeling physicochemical processes in the stratosphere, are also reported. The results show that the conversion of the chlorine reservoir species in the stratosphere to photochemically active forms can occur within a few days of the first appearance of type I PSCs during the polar winter.

  9. A model for heterogeneous chemical processes on the surfaces of ice and nitric acid trihydrate particles

    NASA Technical Reports Server (NTRS)

    Tabazadeh, Azadeh; Turco, Richard P.

    1993-01-01

    The study presents a model that incorporates the physics and physical chemistry of ice surfaces relevant to polar stratospheric clouds. Surface concentrations of H2O, HCl, HOCl, ClONO2, and N2O5 on ice and nitric acid trihydrate (NAT) crystals are computed, and surface reaction rates and reaction probabilities (sticking coefficients) are determined. For gas pressures of about 10 exp -7 torr and temperatures in the range of 180-200 K, HCl completely coats ice and water-rich NAT surfaces, while HOCl, ClOHO2, and N2O5 may cover 0.01-1 percent of these surfaces. The energy parameters are used to calculate surface temperatures such as adsorption and desorption constants, surface coverages, reaction rate coefficients, surface diffusion coefficients, and reaction probabilities for various species and chemical interactions on ice and NAT surfaces. Implications for chemical processing on polar stratospheric clouds are discussed.

  10. Solubility and equilibrium vapor pressures of HC1 dissolved in polar stratospheric cloud materials - Ice and the trihydrate of nitric acid

    NASA Technical Reports Server (NTRS)

    Hanson, David; Mauersberger, Konrad

    1988-01-01

    Measurements of the pressure-solubility behavior of HC1 in water ice and in the nitric acid trihydrate (NAT) crystal at 200 K are reported. It was found that HC1 is about 20 times more soluble in NAT than in ice for stratospheric conditions. A relation between HC1 pressure and substrate composition based on the Gibbs-Duhem equation is developed. This relation, along with other thermodynamic data, can be used to obtain the HC1 pressure-solubility behavior at different temperatures. Implications of these results for the south polar ozone hole are discussed.

  11. A model for heterogeneous chemical processes on the surfaces of ice and nitric acid trihydrate particles

    SciTech Connect

    Tabazadeh, A.; Turco, R.P.

    1993-07-20

    A model is developed that incorporates the physics and physical chemistry of ice surfaces relevant to polar stratospheric clouds. The Langmuir and Brunauer, Emmett, and Teller (BET) adsorption isotherms are used to compute surface concentrations of H{sub 2}O, HCl, HOCl, ClONO{sub 2} and N{sub 2}O{sub 5} on ice and nitric acid trihydrate (NAT) crystals. Assuming pseudo-first-order kinetics with respect to adsorbed HOCl, ClONO{sub 2} and N{sub 2}O{sub 5}, surface reaction rates and reaction probabilities (sticking coefficients) are determined. The model parameters (surface morphology and energies) are extracted from measured uptake coefficients and reaction probabilities. For gas pressures of about 10{sup {minus}7} torr and temperatures in the range of 180-200 K, HCl completely coats ice and water-rich NAT surfaces, while HOCl, ClONO{sub 2} and N{sub 2}O{sub 5} may cover 0.01-1% of these surfaces. The model is applied to analyze laboratory data, leading to estimates of adsorption free energies, enthalpies and entropies for HCl, HOCl, ClONO{sub 2} and N{sub 2}O{sub 5} on ice and NAT surfaces, and activation energies for the heterogeneous reactions of HCl and H{sub 2}O with HOCl, ClONO{sub 2} and N{sub 2}O{sub 5} on these surfaces. The energy parameters are used to calculate surface parameters such as adsorption and desorption consistants, surface coverages, reaction rate coefficients, surface diffusion coefficients and reaction probabilities for various species and chemical interactions on ice and NAT surfaces. Implications for chemical processing on polar stratospheric clouds are discussed. 53 refs., 6 figs., 4 tabs.

  12. Spectroscopic Evidence Against Nitric Acid Trihydrate in Polar Stratospheric Clouds

    NASA Technical Reports Server (NTRS)

    Toon, Owen B.; Tolbert, Margaret A.

    1995-01-01

    Heterogeneous reactions on polar stratospheric clouds (PSC's) play a key role in the photochemical mechanism thought to be responsible for ozone depletion in the Antarctic and Arctic. Reactions of PSC particles activate chlorine to forms that are capable of photochemical ozone destruction, and sequester nitrogen oxides (NOx) that would otherwise deactivate the chlorine. Although the heterogeneous chemistry is now well established, the composition of the clouds themselves is uncertain. It is commonly thought that they are composed of nitric acid trihydrate, although observations have left this question unresolved. Here we reanalyse infrared spectra of type 1 PSCs obtained in Antarctica in September 1987, using recently measured optical constants of the various compounds that might be present in PSCs. We find these PSCs were not composed of nitric acid trihydrate but instead had a more complex compositon, perhaps that of a ternary solution. Because cloud formation is sensitive to their composition, this finding will alter our understanding of the locations and conditions in which PSCs form. In addition, the extent of ozone loss depends on the ability of the PSCs to remove NOx permanently through sedimentation, The sedimentation rates depend on PSC particle size which in turn is controlled by the composition and formation mechanism.

  13. Impact of stratospheric aircraft on calculations of nitric acid trihydrate cloud surface area densities using NMC temperatures and 2D model constituent distributions

    NASA Technical Reports Server (NTRS)

    Considine, David B.; Douglass, Anne R.

    1994-01-01

    A parameterization of NAT (nitric acid trihydrate) clouds is developed for use in 2D models of the stratosphere. The parameterization uses model distributions of HNO3 and H2O to determine critical temperatures for NAT formation as a function of latitude and pressure. National Meteorological Center temperature fields are then used to determine monthly temperature frequency distributions, also as a function of latitude and pressure. The fractions of these distributions which fall below the critical temperatures for NAT formation are then used to determine the NAT cloud surface area density for each location in the model grid. By specifying heterogeneous reaction rates as functions of the surface area density, it is then possible to assess the effects of the NAT clouds on model constituent distributions. We also consider the increase in the NAT cloud formation in the presence of a fleet of stratospheric aircraft. The stratospheric aircraft NO(x) and H2O perturbations result in increased HNO3 as well as H2O. This increases the probability of NAT formation substantially, especially if it is assumed that the aircraft perturbations are confined to a corridor region.

  14. Efficacy of Magnesium Trihydrate of Ursodeoxycholic Acid and Chenodeoxycholic Acid for Gallstone Dissolution: A Prospective Multicenter Trial

    PubMed Central

    Hyun, Jong Jin; Lee, Hong Sik; Kim, Chang Duck; Dong, Seok Ho; Lee, Seung-Ok; Ryu, Ji Kon; Lee, Don Haeng; Jeong, Seok; Kim, Tae Nyeun; Lee, Jin; Koh, Dong Hee; Park, Eun Taek; Lee, Inseok; Yoo, Byung Moo; Kim, Jin Hong

    2015-01-01

    Background/Aims Cholecystectomy is necessary for the treatment of symptomatic or complicated gallbladder (GB) stones, but oral litholysis with bile acids is an attractive alternative therapeutic option for asymptomatic or mildly symptomatic patients. This study was conducted to evaluate the efficacy of magnesium trihydrate of ursodeoxycholic acid (UDCA) and chenodeoxycholic acid (CDCA) on gallstone dissolution and to investigate improvements in gallstone-related symptoms. Methods A prospective, multicenter, phase 4 clinical study to determine the efficacy of orally administered magnesium trihydrate of UDCA and CDCA was performed from January 2011 to June 2013. The inclusion criteria were GB stone diameter ≤15 mm, GB ejection fraction ≥50%, radiolucency on plain X-ray, and asymptomatic/mildly symptomatic patients. The patients were prescribed one capsule of magnesium trihydrate of UDCA and CDCA at breakfast and two capsules at bedtime for 6 months. The dissolution rate, response rate, and change in symptom score were evaluated. Results A total of 237 subjects were enrolled, and 195 subjects completed the treatment. The dissolution rate was 45.1% and the response rate was 47.2% (92/195) after 6 months of administration of magnesium trihydrate of UDCA and CDCA. Only the stone diameter was significantly associated with the response rate. Both the symptom score and the number of patients with symptoms significantly decreased regardless of stone dissolution. Adverse events necessitating discontinuation of the drug, surgery, or endoscopic management occurred in 2.5% (6/237) of patients. Conclusions Magnesium trihydrate of UDCA and CDCA is a well-tolerated bile acid that showed similar efficacy for gallstone dissolution and improvement of gallstone-related symptoms as that shown in previous studies. PMID:26087862

  15. Reaction of ClONO{sub 2} with HCl on NAT, NAD, and frozen sulfuric acid and hydrolysis of N{sub 2}O{sub 5} and ClONO{sub 2} on frozen sulfuric acid

    SciTech Connect

    Hanson, D.R.; Ravishankara, A.R. |

    1993-12-20

    The reaction of ClONO{sub 2} with HCl on the nitric acid trihydrate (NAT) and dihydrate (NAD) and on frozen sulfuric acid solutions was studied as functions of reactant concentration and temperature representative of the stratosphere. A flow tube reactor equipped with a chemical ionization mass spectrometer detector was used. The measured reactive uptake coefficient shows a strong dependence on temperature at constant H{sub 2}O partial pressure. These results for NAT are qualitatively similar to but quantitatively different from those of Abbatt and Molina. The hydrolysis of N{sub 2}O{sub 5} and ClONO{sub 2} on frozen sulfuric acid were measured to be far less efficient than that in liquid solutions. The implications of these results to the heterogeneous chemistry of the stratosphere are discussed. 19 refs., 5 figs., 2 tabs.

  16. Surface properties of superfine alumina trihydrate after surface modification with stearic acid

    NASA Astrophysics Data System (ADS)

    Liu, Gui-hua; Zhou, Bo-hao; Li, Yun-feng; Qi, Tian-gui; Li, Xiao-bin

    2015-05-01

    The surface properties of superfine alumina trihydrate (ATH) after surface modification were studied by measuring the contact angle, active ratio, oil adsorption, total organic carbon, adsorption ratio, and Fourier transform infrared (FTIR) spectrum. The contact angle increased initially and then slowly decreased with an increase of the amount of stearic acid. However, the surface free energy decreased initially and then increased. Surface modification with stearic acid or sodium stearate can benefit from elevating temperature. The base surface tension component and the free energy of Lewis acid-base both declined sharply following the surface modification. Excess stearic acid was physically adsorbed in the form of multilayer adsorption, and an interaction between oxygen on the ATH surface and hydroxyl in stearic acid was subsequently determined. Our results further indicated that the contact angle and adsorption ratio can be used as control indicators for surface modification compared with active ratio, oil adsorption and total organic carbon.

  17. Extreme Nat Supersaturations In Mountain Wave Pscs - A Clue To

    NASA Astrophysics Data System (ADS)

    Luo, B. P.; Voigt, C.; Fuglistaler, S.; Peter, T.

    There is evidence for the existence of nitric acid trihydrate (NAT) in polar stratospheric clouds (PSCs) and for its role in sedimentary denitrification enhancing chlorine- catalyzed ozone reduction. However, the scientific understanding of NAT formation mechanisms is vague. We show that strong cooling rates in mountain waves, though causing only moderate NAT saturation ratio over supercooled ternary solution (STS) droplets (SNAT < 30) lead to NAT saturation ratios exceeding 500 within the gas phase. Laboratory measurements suggest that such extreme supersaturations promote NAT deposition nucleation on ice or other solid surfaces, as long as they are not coated by STS. Based on airborne lidar PSC observations in three Arctic winters and a com- bined microphysical/optical model, we derive a simple parameterization for a NAT deposition nucleation rate which depends only on NAT supersaturation and tempera- ture. The results indicate that deposition nucleation of NAT on ice driven by extreme NAT supersaturations is able to explain the formation of NAT particle number densi- ties in the observed wide range between 10-4 to 10 cm-3.

  18. Heterogeneous interactions of ClONO{sub 2} and HCl on nitric acid trihydrate at 202 K

    SciTech Connect

    Abbatt, J.P.D.; Molina, M.J.

    1992-09-17

    This report uses a mass spectrometer to measure the reaction probabilities of the reactions: ClONO{sub 2} + H{sub 2}O {yields} HOCl + HNO{sub 3} and ClONO{sub 2} + HCl {yields} Cl{sub 2} + HNO{sub 3}, as a function of the pressure of water vapor of the nitric acid trihydrate film.

  19. Antarctic NAT PSC Belt of June 2003: Observational Validation of the Mountain Wave Seeding Hypothesis

    NASA Technical Reports Server (NTRS)

    Eckermann, S. D.; Hoffmann, L.; Hoepfner, M.; Wu, D. L.; Alexander, M. J.

    2009-01-01

    Satellite observations of polar stratospheric clouds (PSCs) over Antarctica in June 2003 revealed small nitric acid trihydrate (NAT) particles forming suddenly along the vortex edge. Models suggest the trigger was mountain waves over the Antarctic Peninsula (AP) forming ice for NAT nucleation. We test this hypothesis by analyzing perturbations in stratospheric radiances from the Atmospheric Infrared Sounder (AIRS). AIRS data show mountain waves over the AP on 10-14 June, with no resolved wave activity before or after. Peak wave temperature amplitudes derived from independent 40 hPa channels all return values of 10-12 K, in agreement with values used to model this NAT event. These observations support a NAT wake from a small region of mountain wave activity over the AP as the source of this circumpolar NAT outbreak.

  20. Knockdown of a nutrient amino acid transporter gene LdNAT1 reduces free neutral amino acid contents and impairs Leptinotarsa decemlineata pupation

    PubMed Central

    Fu, Kai-Yun; Guo, Wen-Chao; Ahmat, Tursun; Li, Guo-Qing

    2015-01-01

    A Leptinotarsa decemlineata SLC6 NAT gene (LdNAT1) was cloned. LdNAT1 was highly expressed in the larval alimentary canal especially midgut. LdNAT1 mRNA levels were high right after the molt and low just before the molt. JH and a JH analog pyriproxyfen activated LdNAT1 expression. RNAi of an allatostatin gene LdAS-C increased JH and upregulated LdNAT1 transcription. Conversely, silencing of a JH biosynthesis gene LdJHAMT decreased JH and reduced LdNAT1 expression. Moreover, 20E and an ecdysteroid agonist halofenozide repressed LdNAT1 expression, whereas a decrease in 20E by RNAi of an ecdysteroidogenesis gene LdSHD and disruption of 20E signaling by knockdown of LdE75 and LdFTZ-F1 activated LdNAT1 expression. Thus, LdNAT1 responded to both 20E and JH. Moreover, knockdown of LdNAT1 reduced the contents of cysteine, histidine, isoleucine, leucine, methionine, phenylalanine and serine in the larval bodies and increased the contents of these amino acids in the larval feces. Furthermore, RNAi of LdNAT1 inhibited insulin/target of rapamycin pathway, lowered 20E and JH titers, reduced 20E and JH signaling, retarded larval growth and impaired pupation. These data showed that LdNAT1 was involved in the absorption of several neutral amino acids critical for larval growth and metamorphosis. PMID:26657797

  1. Metastable NAT in Ice-Clouds

    NASA Astrophysics Data System (ADS)

    Weiss, Fabian; Kubel, Frank; Gálvez, Óscar; Hoelzel, Markus; Parker, Stewart F.; Iannarelli, Riccardo; Rossi, Michel J.; Grothe, Hinrich

    2015-04-01

    Polar Stratospheric Clouds and Cirrus Clouds contain, besides pure water ice, a rather large fraction of various hydrates. These are very important for the formation of the cloud, which is a yet not well understood process. We recently solved the structure of a metastable NAT phase (alpha-NAT), we believe to not only be present, but playing a major role in the formation of clouds. On the basis of previous work on this phase by Grothe et al. [1], we enhanced the production of alpha-NAT to the point, where we could produce enough sample to do neutron diffraction. This enabled us to solve the structure. Our quantum mechanical calculations, using this newly found structure, show a large affinity towards water-ice. With this in mind, we interlaced our results with the experiments of R. Iannarelli [2] to derive a new 3-step NAT-formation mechanism in ice-clouds, which could explain some of the observed kinetics better than the mechanism postulated in Zondlo et al. [3]. 1. Grothe, H., Tizek, H., Waller, D. & Stokes, D. The crystallization kinetics and morphology of nitric acid trihydrate. Phys. Chem. Chem. Phys., 8, 2232-2239 (2006) 2. Iannarelli, R. Multidiagnostic Observations on HCl and HNO3 Hydrate Films in the Temperature Range 170-205K: A Kinetic Study. PhD Thesis 21791, ETH Zürich, (2013). 3. Zondlo, M.A., Hudson, P.K., Prenni A.J. & Tolbert, M.A. Chemistry and microphysics of polar stratospheric clouds and Cirrus clouds. Ann. Rev. Phys. Chem., 51, 473-499 (2000).

  2. 75 FR 22814 - Guidance for Industry: Nucleic Acid Testing (NAT) for Human Immunodeficiency Virus Type 1 (HIV-1...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-04-30

    ... (70 FR 43439), FDA announced the availability of the draft guidance of the same title. FDA received...: Nucleic Acid Testing (NAT) for Human Immunodeficiency Virus Type 1 (HIV-1) and Hepatitis C Virus (HCV... Immunodeficiency Virus Type 1 (HIV-1) and Hepatitis C Virus (HCV): Testing, Product Disposition, and Donor...

  3. Molecular basis of essential amino acid transport from studies of insect nutrient amino acid transporters of the SLC6 family (NAT-SLC6)

    PubMed Central

    Boudko, Dmitri Y.

    2012-01-01

    Two protein families that represent major components of essential amino acid transport in insects have been identified. They are annotated as the SLC6 and SLC7 families of transporters according to phylogenetic proximity to characterized amino acid transporters (HUGO nomenclature). Members of these families have been identified as important apical and basolateral parts of transepithelial essential amino acid absorption in the metazoan alimentary canal. Synergistically, they play critical physiological roles as essential substrate providers to diverse metabolic processes, including generic protein synthesis. This review briefly clarifies the requirements for amino acid transport and a variety of amino acid transport mechanisms, including the aforementioned families. Further it focuses on the large group of Nutrient Amino acid Transporters (NATs), which comprise a recently identified subfamily of the Neurotransmitter Sodium Symporter family (NSS or SLC6). The first insect NAT, cloned from the caterpillar gut, has a broad substrate spectrum similar to mammalian B0 transporters. Several new NAT-SLC6 members have been characterized in an effort to explore mechanisms for the essential amino acid absorption in model dipteran insects. The identification and functional characterization of new B0-like and narrow specificity transporters of essential amino acids in fruit fly and mosquitoes leads to a fundamentally important insight: that NATs evolved and act together as the integrated active core of a transport network that mediates active alimentary absorption and systemic distribution of essential amino acids. This role of NATs is projected from the most primitive prokaryotes to the most complex metazoan organisms, and represents an interesting platform for unraveling the molecular evolution of amino acid transport and modeling amino acid transport disorders. The comparative study of NATs elucidates important adaptive differences between essential amino acid transportomes

  4. Nucleic acid testing (NAT) in high prevalence-low resource settings.

    PubMed

    El Ekiaby, Magdy; Lelie, Nico; Allain, Jean-Pierre

    2010-01-01

    Blood screening by NAT for major transfusion transmitted viral infections (TTIs) was originally intended to complement serology for detection of infected donations. Reports from developed countries showed limited marginal value to NAT blood screening in improving blood safety. Reports on NAT results from Europe indicated yield of 1:0.6 million donations for HBV, <1:M for HCV and HIV-1-related to low prevalence of TTI. In contrast, prevalence of TTI in resource-limited countries is almost always high. As a result, more incident cases can be expected among first-time blood donors. Most reports of NAT blood donation screening in these countries showed NAT confirmed yield as high as 1/2800 for HBV and 1/3100 blood donations for HCV as reported from Thailand and Egypt, respectively. The issues for low resource countries are mostly the high cost of NAT but also the requirements of staff qualification, adequate facilities, reagent procurement and maintenance of delicate equipment. Alternatives to commercial NAT are the use of combos antigen-antibody for HIV and HCV, anti-HBc for HBV and in-house NAT. Most of these alternatives have been reported but very few comparisons are available. Once yield data is available, models for estimation of feasibility and cost-effectiveness are proposed to help decision-making. PMID:20079664

  5. NAT nucleation and denitrification in the polar stratosphere

    NASA Astrophysics Data System (ADS)

    Grooß, Jens-Uwe; Engel, Ines; Hoyle, Christopher R.; Luo, Beiping; Peter, Thomas; Frey, Wiebke; Molleker, Sergej; Borrmann, Stephan; Schlager, Hans; Vömel, Holger; Kivi, Rigel; Walker, Kaley A.; Santee, Michelle L.; Stiller, Gabriele; Pitts, Michael; Müller, Rolf

    2013-04-01

    Nitric acid trihydrate (NAT) particles in the polar stratosphere are known to influence the chemistry of ozone depletion. NAT particles, along with other liquid and crystalline particles, provide heterogeneous surfaces for chlorine activation. More importantly, they can take up significant amounts of HNO3 from the gas phase and transport HNO3 downward by sedimentation. This can lead to denitrification, in the Arctic typically at altitudes above about 20 km, and a re-nitrification below, at the level where the NAT particles evaporate. The nucleation rate of NAT particles is a critical parameter for the simulation of this process. Very low NAT nucleation rates around 2?10-9cm-3s-1 have been deduced for low NAT supersaturations from observations. In previous studies, vertical HNO3 transport has been successfully simulated by Lagrangian 3-D simulations using a constant NAT nucleation rate of around 2?10-9cm-3s-1, for the Arctic winters in the years 2003 and 2005. However, for winter 2009/2010, this approach does not generate satisfying results. Here, saturation dependent NAT nucleation rates were derived from Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), observations under the assumption that NAT nucleates heterogeneously on dust particles that are characterized by active sites with a certain occurrence probability distribution depending on the contact angle. Simulations with the Zurich Optical and Microphysical box Model (ZOMM) along back-trajectories starting from points where PSCs were observed by CALIPSO allow the parametrisation of heterogeneous nucleation rates for NAT and ice on dust, and the reproduction of the different PSC classes observed. We present simulations by the Chemical Lagrangian Model of the Stratosphere (CLaMS) of the winter 2009/2010 applying this new parametrisation of heterogeneous NAT nucleation rates. The CLaMS simulation is initialized using a combination of MLS, MIPAS-ENVISAT and ACE-FTS data. The simulation

  6. Growth of nitric acid hydrates on thin sulfuric acid films

    NASA Technical Reports Server (NTRS)

    Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

    1994-01-01

    Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1-3 x 10(exp -4) Torr H2O and 1-2.5 x 10(exp -6) Torr HNO3) and subjected to cooling and heating cycles. Fourier Transform Infrared (FTIR) spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

  7. Growth of nitric acid hydrates on thin sulfuric acid films

    NASA Astrophysics Data System (ADS)

    Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.

    1994-05-01

    Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1 - 3 × 10-4 Torr H2O and 1 - 2.5 × 10-6 Torr HNO3) and subjected to cooling and heating cycles. FTIR spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.

  8. Multiple Advantageous Amino Acid Variants in the NAT2 Gene in Human Populations

    PubMed Central

    Luca, Francesca; Bubba, Giuseppina; Basile, Massimo; Brdicka, Radim; Michalodimitrakis, Emmanuel; Rickards, Olga; Vershubsky, Galina; Quintana-Murci, Lluis; Kozlov, Andrey I.; Novelletto, Andrea

    2008-01-01

    Background Genetic variation at NAT2 has been long recognized as the cause of differential ability to metabolize a wide variety of drugs of therapeutic use. Here, we explore the pattern of genetic variation in 12 human populations that significantly extend the geographic range and resolution of previous surveys, to test the hypothesis that different dietary regimens and lifestyles may explain inter-population differences in NAT2 variation. Methodology/Principal Findings The entire coding region was resequenced in 98 subjects and six polymorphic positions were genotyped in 150 additional subjects. A single previously undescribed variant was found (34T>C; 12Y>H). Several aspects of the data do not fit the expectations of a neutral model, as assessed by coalescent simulations. Tajima's D is positive in all populations, indicating an excess of intermediate alleles. The level of between-population differentiation is low, and is mainly accounted for by the proportion of fast vs. slow acetylators. However, haplotype frequencies significantly differ across groups of populations with different subsistence. Conclusions/Significance Data on the structure of haplotypes and their frequencies are compatible with a model in which slow-causing variants were present in widely dispersed populations before major shifts to pastoralism and/or agriculture. In this model, slow-causing mutations gained a selective advantage in populations shifting from hunting-gathering to pastoralism/agriculture. We suggest the diminished dietary availability of folates resulting from the nutritional shift, as the possible cause of the fitness increase associated to haplotypes carrying mutations that reduce enzymatic activity. PMID:18773084

  9. Validated stability-indicating spectrophotometric methods for the determination of cefixime trihydrate in the presence of its acid and alkali degradation products.

    PubMed

    Mostafa, Nadia M; Abdel-Fattah, Laila; Weshahy, Soheir A; Hassan, Nagiba Y; Boltia, Shereen A

    2015-01-01

    Five simple, accurate, precise, and economical spectrophotometric methods have been developed for the determination of cefixime trihydrate (CFX) in the presence of its acid and alkali degradation products without prior separation. In the first method, second derivative (2D) and first derivative (1D) spectrophotometry was applied to the absorption spectra of CFX and its acid (2D) or alkali (1D) degradation products by measuring the amplitude at 289 and 308 nm, respectively. The second method was a first derivative (1DD) ratio spectrophotometric method where the peak amplitudes were measured at 311 nm in presence of the acid degradation product, and 273 and 306 nm in presence of its alkali degradation product. The third method was ratio subtraction spectrophotometry where the drug is determined at 286 nm in laboratory-prepared mixtures of CFX and its acid or alkali degradation product. The fourth method was based on dual wavelength analysis; two wavelengths were selected at which the absorbances of one component were the same, so wavelengths 209 and 252 nm were used to determine CFX in presence of its acid degradation product and 310 and 321 nm in presence of its alkali degradation product. The fifth method was bivariate spectrophotometric calibration based on four linear regression equations obtained at the wavelengths 231 and 290 nm, and 231 and 285 nm for the binary mixture of CFX with either its acid or alkali degradation product, respectively. The developed methods were successfully applied to the analysis of CFX in laboratory-prepared mixtures and pharmaceutical formulations with good recoveries, and their validation was carried out following the International Conference on Harmonization guidelines. The results obtained were statistically compared with each other and showed no significant difference with respect to accuracy and precision. PMID:25857876

  10. 21 CFR 520.88h - Amoxicillin trihydrate and clavulanate potassium for oral suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Amoxicillin trihydrate and clavulanate potassium... NEW ANIMAL DRUGS § 520.88h Amoxicillin trihydrate and clavulanate potassium for oral suspension. (a... of amoxicillin with clavulanate potassium equivalent to 12.5 milligrams of clavulanic acid....

  11. 21 CFR 520.88h - Amoxicillin trihydrate and clavulanate potassium for oral suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amoxicillin trihydrate and clavulanate potassium... NEW ANIMAL DRUGS § 520.88h Amoxicillin trihydrate and clavulanate potassium for oral suspension. (a... of amoxicillin with clavulanate potassium equivalent to 12.5 milligrams of clavulanic acid....

  12. 21 CFR 520.88h - Amoxicillin trihydrate and clavulanate potassium for oral suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Amoxicillin trihydrate and clavulanate potassium... NEW ANIMAL DRUGS § 520.88h Amoxicillin trihydrate and clavulanate potassium for oral suspension. (a... of amoxicillin with clavulanate potassium equivalent to 12.5 milligrams of clavulanic acid....

  13. 21 CFR 520.88h - Amoxicillin trihydrate and clavulanate potassium for oral suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Amoxicillin trihydrate and clavulanate potassium... NEW ANIMAL DRUGS § 520.88h Amoxicillin trihydrate and clavulanate potassium for oral suspension. (a... of amoxicillin with clavulanate potassium equivalent to 12.5 milligrams of clavulanic acid....

  14. 21 CFR 520.88h - Amoxicillin trihydrate and clavulanate potassium for oral suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Amoxicillin trihydrate and clavulanate potassium... NEW ANIMAL DRUGS § 520.88h Amoxicillin trihydrate and clavulanate potassium for oral suspension. (a... of amoxicillin with clavulanate potassium equivalent to 12.5 milligrams of clavulanic acid....

  15. Laboratory studies of the formation of polar stratospheric clouds: Nitric acid condensation on thin sulfuric acid films

    NASA Astrophysics Data System (ADS)

    Iraci, Laura T.; Middlebrook, Ann M.; Tolbert, Margaret A.

    1995-10-01

    Thin sulfuric acid films were exposed to 5 × 10-8 - 8 × 10-7 torr HNO3 and 2 - 3 × 10-4 torr H2O and cooled to temperatures near the ice frost point. Fourier transform infrared (FTIR) spectroscopy was used to probe the condensed-phase species during isothermal experiments, and gas pressures were monitored with mass spectrometry. Supercooled liquid sulfuric acid films exposed to HNO3 (6 ≤ SNAT ≤ 114) showed indications of HNO3 uptake to form ternary solutions of approximately 4 wt % HNO3, 38 wt % H2SO4, and 59 wt % H2O, followed by crystallization of nitric acid trihydrate (NAT). NAT crystallization did not initiate significant crystallization of the supercooled H2SO4, but the H2SO4 often crystallized to sulfuric acid tetrahydrate (SAT) upon warming. In contrast, when crystalline SAT films were exposed to HNO3 and water, NAT did not condense within several hours, even at HNO3 saturation ratios of 30 or higher. Calculations of the contact parameter from experimental data indicate that m <0.76 for NAT on SAT. Our film studies suggest that crystalline polar stratospheric cloud (PSC) growth is most easily accomplished when stratospheric sulfate aerosols (SSAs) remain liquid, absorb HNO3, and produce crystalline nitric acid trihydrate via heterogeneous nucleation. If SSAs crystallize to SAT at some point during the winter, nitric acid condensation is hindered, and PSC formation could become more difficult.

  16. Fourier transform infrared studies of model polar stratospheric cloud surfaces - Growth and evaporation of ice and nitric acid/ice

    NASA Technical Reports Server (NTRS)

    Tolbert, Margaret A.; Middlebrook, Ann M.

    1990-01-01

    Fourier-transform infrared surface studies are used to probe the microphysical properties of nitric acid trihydrate (NAT) and ice films representative of type I and II polar stratospheric clouds (PSC). Experiments indicate that, on initial exposure to 1.8 microtorr of HNO3, a layer of ice is quantitatively converted to NAT. However, conversion of ice to NAT does not proceed indefinitely, but rather the system reaches saturation. For longer exposures or higher HNO3 pressures, NAM becomes the dominant nitric acid containing species on the surface. Evaporation studies were performed to test the feasibility of a recent denitrification mechanism. The results indicate that ice coated with 0.20 micron of NAT evaporates at a temperature of about 4 C higher than uncoated ice.

  17. Contribution of liquid, NAT and ice particles to chlorine activation and ozone depletion in Antarctic winter and spring

    NASA Astrophysics Data System (ADS)

    Kirner, O.; Müller, R.; Ruhnke, R.; Fischer, H.

    2015-02-01

    Heterogeneous reactions in the Antarctic stratosphere are the cause of chlorine activation and ozone depletion, but the relative roles of different types of polar stratospheric clouds (PSCs) in chlorine activation is an open question. We use multi-year simulations of the chemistry-climate model ECHAM5/MESSy for Atmospheric Chemistry (EMAC) to investigate the impact that the various types of PSCs have on Antarctic chlorine activation and ozone loss. One standard and three sensitivity EMAC simulations have been performed. In all simulations a Newtonian relaxation technique using the ERA-Interim reanalysis was applied to simulate realistic synoptic conditions. In the three sensitivity simulations, we only changed the heterogeneous chemistry on PSC particles by switching the chemistry on liquid, nitric acid trihydrate (NAT) and ice particles on and off. The results of these simulations show that the significance of heterogeneous reactions on NAT and ice particles for chlorine activation and ozone depletion in Antarctic winter and spring is small in comparison to the significance of heterogeneous reactions on liquid particles. Liquid particles alone are sufficient to activate almost all of the available chlorine, with the exception of the upper PSC regions between 10 and 30 hPa, where temporarily ice particles show a relevant contribution. Shortly after the first PSC occurrence, NAT particles contribute a small fraction to chlorine activation. Heterogeneous chemistry on liquid particles is responsible for more than 90% of the ozone depletion in Antarctic spring in the model simulations. In high southern latitudes, heterogeneous chemistry on ice particles causes only up to 5 DU of additional ozone depletion in the column and heterogeneous chemistry on NAT particles less than 0.5 DU. The simulated HNO3, ClO and O3 results agree closely with observations from the Microwave Limb Sounder (MLS) onboard NASA's Aura satellite.

  18. ISCCP TOVS NAT

    Atmospheric Science Data Center

    2016-02-12

    ISCCP TOVS NAT Atmospheric Profiles, NATIVE file format Project Title:  ... Parameters:  Cloud Amount Cloud Top Pressure Ozone Precipitable Water Profiles Surface Pressure Surface Temperature Temperature Profiles Tropopause Pressure ...

  19. NAT: perspectives for cellular components.

    PubMed

    Barbara, J A

    1999-12-01

    The introduction of routine testing to detect viral genomes in donated blood was originally driven by requirements for plasma fractionation in relation to exclusion of hepatitis C virus (HCV) RNA. Nevertheless, it was obvious from the outset that a dual standard for fractionated products and individual blood components would be untenable. In many countries therefore, planning for introduction of nucleic acid testing (NAT) of blood incorporated progression to release of HCV RNA tested components. HCV was singled out because of its long seronegative 'window period', relatively high prevalence and incidence in blood donors, rapid burst time and high genome copy number during seroconversion. The latter properties made HCV particularly suitable for detection in pools of samples. If HCV RNA testing is required for release of labile components such as platelets, rapid provision of NAT results is vital because of short shelf life of platelets and the problems of delays when resolving the infectious unit in a reactive pool. For NAT release of labile components smaller sample pool sizes allow faster resolution of RNA positive units. Smaller pools involve high test throughput, the likely need for more testing laboratories and ensuing increased costs. Single sample testing is the ultimate extrapolation of reducing sample pool size. With reduced pool sizes or single sample testing, the option of testing for other viruses (e.g. HIV or HBV) singly or in multiplex also arises. The cost-benefit and incremental yield of such strategies in the light of 'combo' assays for HIV Ag/Ab and the recently described HCV Ag assay will require careful and objective assessment, together with re-appraisal of anti-HBc screening for detection of HBV infected donors at the "tail-end" of carriage. PMID:10686060

  20. 21 CFR 520.88d - Amoxicillin trihydrate soluble powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amoxicillin trihydrate soluble powder. 520.88d... trihydrate soluble powder. (a) Specifications. Each gram contains amoxicillin trihydrate equivalent to 115.4... veal calves. (3) Limitations. Administer by drench or by mixing in milk. Treatment should be...

  1. 21 CFR 520.90e - Ampicillin trihydrate soluble powder.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ampicillin trihydrate soluble powder. 520.90e Section 520.90e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... trihydrate soluble powder. (a) Specifications. Each gram contains ampicillin trihydrate equivalent to...

  2. 21 CFR 520.90e - Ampicillin trihydrate soluble powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Ampicillin trihydrate soluble powder. 520.90e Section 520.90e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... trihydrate soluble powder. (a) Specifications. Each gram contains ampicillin trihydrate equivalent to...

  3. 21 CFR 520.88d - Amoxicillin trihydrate soluble powder.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Amoxicillin trihydrate soluble powder. 520.88d Section 520.88d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... trihydrate soluble powder. (a) Specifications. Each gram contains amoxicillin trihydrate equivalent to...

  4. Spectroscopic evidence of large aspherical β-NAT particles involved in denitrification in the December 2011 Arctic stratosphere

    NASA Astrophysics Data System (ADS)

    Woiwode, Wolfgang; Höpfner, Michael; Bi, Lei; Pitts, Michael C.; Poole, Lamont R.; Oelhaf, Hermann; Molleker, Sergej; Borrmann, Stephan; Klingebiel, Marcus; Belyaev, Gennady; Ebersoldt, Andreas; Griessbach, Sabine; Grooß, Jens-Uwe; Gulde, Thomas; Krämer, Martina; Maucher, Guido; Piesch, Christof; Rolf, Christian; Sartorius, Christian; Spang, Reinhold; Orphal, Johannes

    2016-07-01

    We analyze polar stratospheric cloud (PSC) signatures in airborne MIPAS-STR (Michelson Interferometer for Passive Atmospheric Sounding - STRatospheric aircraft) observations in the spectral regions from 725 to 990 and 1150 to 1350 cm-1 under conditions suitable for the existence of nitric acid trihydrate (NAT) above northern Scandinavia on 11 December 2011. The high-resolution infrared limb emission spectra of MIPAS-STR show a characteristic "shoulder-like" signature in the spectral region around 820 cm-1, which is attributed to the ν2 symmetric deformation mode of NO3- in β-NAT. Using radiative transfer calculations involving Mie and T-Matrix methods, the spectral signatures of spherical and aspherical particles are simulated. The simulations are constrained using collocated in situ particle measurements. Simulations assuming highly aspherical spheroids with aspect ratios (AR) of 0.1 or 10.0 and a lognormal particle mode with a mode radius of 4.8 µm reproduce the observed spectra to a high degree. A smaller lognormal mode with a mode radius of 2.0 µm, which is also taken into account, plays only a minor role. Within the scenarios analyzed, the best overall agreement is found for elongated spheroids with AR = 0.1. Simulations of spherical particles and spheroids with AR = 0.5 and 2.0 return results very similar to each other and do not allow us to reproduce the signature around 820 cm-1. The observed "shoulder-like" signature is explained by the combination of the absorption/emission and scattering characteristics of large highly aspherical β-NAT particles. The size distribution supported by our results corresponds to ˜ 9 ppbv of gas-phase equivalent HNO3 at the flight altitude of ˜ 18.5 km. The results are compared with the size distributions derived from the in situ observations, a corresponding Chemical Lagrangian Model of the Stratosphere (CLaMS) simulation, and excess gas-phase HNO3 observed in a nitrification layer directly below the observed PSC. The

  5. Genetic polymorphism in N-Acetyltransferase (NAT): Population distribution of NAT1 and NAT2 activity.

    PubMed

    Walker, Katy; Ginsberg, Gary; Hattis, Dale; Johns, Douglas O; Guyton, Kathryn Z; Sonawane, Babasaheb

    2009-01-01

    N-Acetyltransferases (NAT) are key enzymes in the conjugation of certain drugs and other xenobiotics with an arylamine structure. Polymorphisms in NAT2 have long been recognized to modulate toxicity produced by the anti-tubercular drug isoniazid, with molecular epidemiologic studies suggesting a link between acetylator phenotype and increased risk for bladder cancer. Recent evidence indicates that the other major NAT isozyme, NAT1, is also polymorphic. The current analysis characterizes the main polymorphisms in both NAT2 and NAT1 in terms of their effect on enzyme activity and frequency in the population. Multiple NAT2 alleles (NAT2*5, *6, *7, and *14) have substantially decreased acetylation activity and are common in Caucasians and populations of African descent. In these groups, most individuals carry at least one copy of a slow acetylator allele, and less than 10% are homozygous for the wild type (fast acetylator) trait. Incorporation of these data into a Monte Carlo modeling framework led to a population distribution of NAT2 activity that was bimodal and associated with considerable variability in each population assessed. The ratio of the median to the first percentile of NAT2 activity ranged from 7 in Caucasians to 18 in the Chinese population. This variability indicates the need for more quantitative approaches (e.g., physiologically based pharmacokinetic [PBPK] modeling) to assess the full distribution of internal dose and adverse responses to aromatic amines and other NAT2 substrates. Polymorphisms in NAT1 are generally associated with relatively minor effects on acetylation function, with Monte Carlo analysis indicating less interindividual variability than seen in NAT2 analysis. PMID:20183529

  6. High-speed civil transport impact: Role of sulfate, nitric acid trihydrate, and ice aerosols studied with a two-dimensional model including aerosol physics

    SciTech Connect

    Pitari, G.; Ricciardulli, L.; Visconti, G.; Rizi, V.

    1993-12-20

    The authors discuss a two-dimensional model used to study the atmospheric interactions of ozone with exhaust gases from high speed civil transport (HSCT) fleets. Their model encompases the stratosphere and troposphere, includes photochemical reactions as part of the sulfur cycle, and models sulfuric acid aerosols. The inclusion of heterogeneous chemistry effects tempers the impact of nitrogen oxide emissions from HSCT on ozone depletion, in support of previous work from other studies.

  7. NAT Usage in Residential Broadband Networks

    NASA Astrophysics Data System (ADS)

    Maier, Gregor; Schneider, Fabian; Feldmann, Anja

    Many Internet customers use network address translation (NAT) when connecting to the Internet. To understand the extend of NAT usage and its implications, we explore NAT usage in residential broadband networks based on observations from more than 20,000 DSL lines. We present a unique approach for detecting the presence of NAT and for estimating the number of hosts connected behind a NAT gateway using IP TTLs and HTTP user-agent strings. Furthermore, we study when each of the multiple hosts behind a single NAT gateway is active. This enables us to detect simultaneous use. In addition, we evaluate the accuracy of NAT analysis techniques when fewer information is available.

  8. 21 CFR 520.88f - Amoxicillin trihydrate tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amoxicillin trihydrate tablets. 520.88f Section 520.88f Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88f Amoxicillin trihydrate tablets. (a) Specifications....

  9. 21 CFR 520.90b - Ampicillin trihydrate tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ampicillin trihydrate tablets. 520.90b Section 520.90b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90b Ampicillin trihydrate tablets. (a) Specifications. Each...

  10. 21 CFR 520.88e - Amoxicillin trihydrate boluses.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amoxicillin trihydrate boluses. 520.88e Section 520.88e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88e Amoxicillin trihydrate boluses. (a) Specifications....

  11. 21 CFR 520.88c - Amoxicillin trihydrate oral suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amoxicillin trihydrate oral suspension. 520.88c Section 520.88c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88c Amoxicillin trihydrate oral suspension....

  12. 21 CFR 520.88c - Amoxicillin trihydrate oral suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Amoxicillin trihydrate oral suspension. 520.88c Section 520.88c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88c Amoxicillin trihydrate oral suspension....

  13. 21 CFR 520.88e - Amoxicillin trihydrate boluses.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Amoxicillin trihydrate boluses. 520.88e Section 520.88e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88e Amoxicillin trihydrate boluses. (a) Specifications....

  14. 21 CFR 520.88d - Amoxicillin trihydrate soluble powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Amoxicillin trihydrate soluble powder. 520.88d Section 520.88d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88d Amoxicillin trihydrate soluble powder....

  15. 21 CFR 520.88c - Amoxicillin trihydrate oral suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Amoxicillin trihydrate oral suspension. 520.88c Section 520.88c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88c Amoxicillin trihydrate oral suspension....

  16. 21 CFR 520.88e - Amoxicillin trihydrate boluses.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Amoxicillin trihydrate boluses. 520.88e Section 520.88e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88e Amoxicillin trihydrate boluses. (a) Specifications....

  17. 21 CFR 520.88c - Amoxicillin trihydrate oral suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Amoxicillin trihydrate oral suspension. 520.88c Section 520.88c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88c Amoxicillin trihydrate oral suspension....

  18. 21 CFR 520.88d - Amoxicillin trihydrate soluble powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Amoxicillin trihydrate soluble powder. 520.88d Section 520.88d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88d Amoxicillin trihydrate soluble powder....

  19. 21 CFR 520.88e - Amoxicillin trihydrate boluses.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Amoxicillin trihydrate boluses. 520.88e Section 520.88e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88e Amoxicillin trihydrate boluses. (a) Specifications....

  20. 21 CFR 522.90b - Ampicillin trihydrate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Ampicillin trihydrate. 522.90b Section 522.90b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.90b Ampicillin trihydrate. (a) Specifications....

  1. 21 CFR 520.88c - Amoxicillin trihydrate oral suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Amoxicillin trihydrate oral suspension. 520.88c Section 520.88c Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88c Amoxicillin trihydrate oral suspension....

  2. 21 CFR 520.88d - Amoxicillin trihydrate soluble powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Amoxicillin trihydrate soluble powder. 520.88d Section 520.88d Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88d Amoxicillin trihydrate soluble powder....

  3. 21 CFR 520.88e - Amoxicillin trihydrate boluses.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Amoxicillin trihydrate boluses. 520.88e Section 520.88e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.88e Amoxicillin trihydrate boluses. (a) Specifications....

  4. 21 CFR 520.90e - Ampicillin trihydrate soluble powder.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ampicillin trihydrate soluble powder. 520.90e Section 520.90e Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.90e Ampicillin trihydrate soluble powder....

  5. 21 CFR 522.90b - Ampicillin trihydrate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Ampicillin trihydrate. 522.90b Section 522.90b Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS IMPLANTATION OR INJECTABLE DOSAGE FORM NEW ANIMAL DRUGS § 522.90b Ampicillin trihydrate. (a) Specifications....

  6. Infrared studies of sulfuric acid and its impact on polar and global ozone

    NASA Astrophysics Data System (ADS)

    Iraci, Laura Tracy

    Sulfuric acid aerosols are present throughout the lower stratosphere and play an important role in both polar and global ozone depletion. In the polar regions, stratospheric sulfate aerosols (SSAs) act as nuclei for the growth of polar stratospheric clouds (PSCs). Heterogeneous reactions can occur on these PSCs, leading to chlorine activation and catalytic ozone destruction. This thesis addresses the issue of polar ozone depletion through laboratory studies which examine the nucleation of PSCs on sulfuric acid. In addition, chemistry which occurs directly on sulfate aerosols may impact ozone at midlatitudes, and studies describing one such reaction are presented as well. To study the growth of type I PSCs on sulfuric acid, thin H2SO4 films were exposed to water and nitric acid vapors at stratospheric temperatures. Fourier transform infrared spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films which condensed. Supercooled liquid sulfuric acid films showed uptake of HNO3 to form ternary solutions, followed by crystallization of nitric acid trihydrate (NAT). When crystalline sulfuric acid tetrahydrate (SAT) films were exposed to nitric acid and water, condensation of a supercooled HNO3/H2O layer was often observed. As predicted by theory, some of the SAT crystal then dissolved, creating a ternary H2SO4/HNO3/H2O solution. From this solution, NAT nearly always crystallized, halting the phase change of sulfuric acid. If a supercooled nitric acid layer did not condense on frozen sulfuric acid, crystalline NAT was not deposited from the gas phase when SNAT/leq41. At significantly higher supersaturations, NAT could be forced to condense on sulfuric acid, regardless of its phase. Calculations of the contact parameter from experimental data indicate that m<0.79 for NAT on SAT, predicting a significant barrier to nucleation of NAT from the gas phase. While PSCs can form only in the cold polar regions of the stratosphere, sulfuric

  7. Crystal structure of potassium sodium tartrate trihydrate

    SciTech Connect

    Egorova, A. E. Ivanov, V. A.; Somov, N. V.; Portnov, V. N.; Chuprunov, E. V.

    2011-11-15

    Crystals of potassium sodium tartrate trihydrate (dl-KNaC{sub 4}H{sub 4}O{sub 6} {center_dot} 3H{sub 2}O) were obtained from an aqueous solution. The crystal shape was described. The atomic structure of the compound was determined and compared with the known structures of dl-KNaC{sub 4}H{sub 4}O{sub 6} {center_dot} 4H{sub 2}O and l-KNaC{sub 4}H{sub 4}O{sub 6} {center_dot} 4H{sub 2}O.

  8. Genetic Variation at the N-acetyltransferase (NAT) Genes in Global Populations

    EPA Science Inventory

    Functional variability at the N-acetyltransferase (NAT) genes is associated with adverse drug reactions and cancer susceptibility in humans. Previous studies of small sets of ethnic groups have indicated that the NAT genes have high levels of amino acid variation that differ in f...

  9. N-acetyltransferase 2 (Nat2) polymorphism in the sand rat Psammomys obesus.

    PubMed

    Khelil, Malika; Djerdjouri, Bahia; Tayebi, Bouchentouf

    2010-10-01

    Human arylamine N-acetyltransferase 1 (NAT1) and its homologue in rodents (Nat2) are polymorphic xenobiotic metabolizing enzymes and also seem to play a role in endogenous metabolism. NAT1 and Nat2 polymorphism was associated to cancers under xenobiotic procarcinogens metabolism as well as under endogenous substrate metabolism. This study investigated the p-aminobenzoic acid (PABA) -Nat2 catalytic activity and its polymorphism in liver homogenates of adult sand rats Psammomys obesus Cretzschmar, 1828. These Saharian sand rats develop high incidence of spontaneous cancers under standard laboratory diet. The average value of PABA-Nat2 specific activity tested in nine sand rats was significant (2.96 ± 2.16 nmoles/min/mg). The N-acetylation exhibited a bimodal distribution. There was a significant difference (p<0.01) between PABA-Nat2 activity in the fast acetylators group (4.10 ± 1.67 nmol/min/mg) and slow acetylators group (0.7 ± 0.27 nmol/min/mg). The percentage of the fast acetylator group was 66.66%. These results support the presence of Nat2 polymorphism in the liver of the strain sand rats Psammomys obesus. This strain is useful for investigating the role of Nat2 polymorphisms in susceptibility to cancers related to arylamine carcinogen exposures as well as to endogenous substrate metabolism. PMID:20550432

  10. 40 CFR 721.10562 - Aluminum trihydrate and silane homopolymer (generic).

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Aluminum trihydrate and silane... Specific Chemical Substances § 721.10562 Aluminum trihydrate and silane homopolymer (generic). (a) Chemical... as aluminum trihydrate and silane homopolymer (PMN P-07-375) is subject to reporting under...

  11. 40 CFR 721.10562 - Aluminum trihydrate and silane homopolymer (generic).

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Aluminum trihydrate and silane... Specific Chemical Substances § 721.10562 Aluminum trihydrate and silane homopolymer (generic). (a) Chemical... as aluminum trihydrate and silane homopolymer (PMN P-07-375) is subject to reporting under...

  12. 21 CFR 520.88g - Amoxicillin trihydrate and clavulanate potassium film-coated tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Amoxicillin trihydrate and clavulanate potassium... ANIMAL DRUGS § 520.88g Amoxicillin trihydrate and clavulanate potassium film-coated tablets. (a) Specifications. Each tablet contains amoxicillin trihydrate and clavulanate potassium, equivalent to either...

  13. 21 CFR 520.88g - Amoxicillin trihydrate and clavulanate potassium film-coated tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Amoxicillin trihydrate and clavulanate potassium... ANIMAL DRUGS § 520.88g Amoxicillin trihydrate and clavulanate potassium film-coated tablets. (a) Specifications. Each tablet contains amoxicillin trihydrate and clavulanate potassium, equivalent to either...

  14. 21 CFR 520.88g - Amoxicillin trihydrate and clavulanate potassium film-coated tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Amoxicillin trihydrate and clavulanate potassium... ANIMAL DRUGS § 520.88g Amoxicillin trihydrate and clavulanate potassium film-coated tablets. (a) Specifications. Each tablet contains amoxicillin trihydrate and clavulanate potassium, equivalent to either...

  15. 21 CFR 520.88g - Amoxicillin trihydrate and clavulanate potassium film-coated tablets.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Amoxicillin trihydrate and clavulanate potassium... ANIMAL DRUGS § 520.88g Amoxicillin trihydrate and clavulanate potassium film-coated tablets. (a) Specifications. Each tablet contains amoxicillin trihydrate and clavulanate potassium, equivalent to either...

  16. 21 CFR 520.88g - Amoxicillin trihydrate and clavulanate potassium film-coated tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Amoxicillin trihydrate and clavulanate potassium... ANIMAL DRUGS § 520.88g Amoxicillin trihydrate and clavulanate potassium film-coated tablets. (a) Specifications. Each tablet contains amoxicillin trihydrate and clavulanate potassium, equivalent to either...

  17. CFH Y402H and ARMS2 A69S Polymorphisms and Oral Supplementation with Docosahexaenoic Acid in Neovascular Age-Related Macular Degeneration Patients: The NAT2 Study

    PubMed Central

    Merle, Bénédicte M. J.; Richard, Florence; Benlian, Pascale; Puche, Nathalie; Delcourt, Cécile; Souied, Eric H.

    2015-01-01

    Purpose Genetic susceptibility could be modified by environmental factors and may also influence differential responses to treatments for age-related macular degeneration (AMD). We investigated whether genotype could influence response to docosahexaenoic acid (DHA)-supplementation in the occurrence of choroidal new vessels (CNV). Methods The Nutritional AMD Treatment 2 (NAT2) study was a randomized, placebo-controlled, double-blind, parallel, comparative study, including 250 patients aged 55 to 85 years with early lesions of age-related maculopathy, visual acuity better than 0.4 Logarithm of Minimum Angle of Resolution units in the study eye and neovascular AMD in the fellow eye. Patients were randomized at baseline to receive either 3 daily fish-oil capsules, each containing 280 mg DHA, 90 mg EPA and 2 mg Vitamin E, or placebo. Results Patients carrying the risk allele (C) for CFH Y402H had no statistically significant increased risk for developing CNV in the study eye (Hazard Ratio (HR)=0.97; 95% Confidence Interval (CI): 0.54-1.76 for heterozygous and HR=1.29; 95%CI: 0.69-2.40 for homozygous). Patients carrying the risk allele (T) for ARMS2 A69S had no statistically significant increased risk for developing CNV in the study eye (HR=1.68; 95%CI: 0.91-3.12) for heterozygous and HR=1.78; 95%CI: 0.90-3.52 for homozygous). A significant interaction was observed between CFH Y402H and DHA-supplementation (p=0.01). We showed a protective effect of DHA-supplementation among homozygous non-risk patients. Among these patients, occurrence of CNV was 38.2% in placebo group versus 16.7% in DHA group (p=0.008). Conclusions These results suggest that a genetic predisposition to AMD conferred by the CFH Y402H variant limits the benefit provided by DHA supplementation. Trial Registration ISRCTN registry 98246501 PMID:26132079

  18. Rapid birth-and-death evolution of the xenobiotic metabolizing NAT gene family in vertebrates with evidence of adaptive selection

    PubMed Central

    2013-01-01

    Background The arylamine N-acetyltransferases (NATs) are a unique family of enzymes widely distributed in nature that play a crucial role in the detoxification of aromatic amine xenobiotics. Considering the temporal changes in the levels and toxicity of environmentally available chemicals, the metabolic function of NATs is likely to be under adaptive evolution to broaden or change substrate specificity over time, making NATs a promising subject for evolutionary analyses. In this study, we trace the molecular evolutionary history of the NAT gene family during the last ~450 million years of vertebrate evolution and define the likely role of gene duplication, gene conversion and positive selection in the evolutionary dynamics of this family. Results A phylogenetic analysis of 77 NAT sequences from 38 vertebrate species retrieved from public genomic databases shows that NATs are phylogenetically unstable genes, characterized by frequent gene duplications and losses even among closely related species, and that concerted evolution only played a minor role in the patterns of sequence divergence. Local signals of positive selection are detected in several lineages, probably reflecting response to changes in xenobiotic exposure. We then put a special emphasis on the study of the last ~85 million years of primate NAT evolution by determining the NAT homologous sequences in 13 additional primate species. Our phylogenetic analysis supports the view that the three human NAT genes emerged from a first duplication event in the common ancestor of Simiiformes, yielding NAT1 and an ancestral NAT gene which in turn, duplicated in the common ancestor of Catarrhini, giving rise to NAT2 and the NATP pseudogene. Our analysis suggests a main role of purifying selection in NAT1 protein evolution, whereas NAT2 was predicted to mostly evolve under positive selection to change its amino acid sequence over time. These findings are consistent with a differential role of the two human isoenzymes

  19. A laboratory study of the nucleation kinetics of nitric acid hydrates under stratospheric conditions

    NASA Astrophysics Data System (ADS)

    James, Alexander D.; Murray, Benjamin J.; Plane, John M. C.

    2016-04-01

    Measurements of the kinetics of crystallisation of ternary H2O-H2SO4-HNO3 mixtures to produce nitric acid hydrate phases, as occurs in the lower stratosphere, have been a long-standing challenge for investigators in the laboratory. Understanding polar stratospheric chlorine chemistry and thereby ozone depletion is increasingly limited by descriptions of nucleation processes. Meteoric smoke particles have been considered in the past as heterogeneous nuclei, however recent studies suggest that these particles will largely dissolve, leaving mainly silica and alumina as solid inclusions. In this study the nucleation kinetics of nitric acid hydrate phases have been measured in microliter droplets at polar stratospheric cloud (PSC) temperatures, using a droplet freezing assay. A clear heterogeneous effect was observed when silica particles were added. A parameterisation based on the number of droplets activated per nuclei surface area (ns) has been developed and compared to global model data. Nucleation experiments on identical droplets have been performed in an X-Ray Diffractometer (XRD) to determine the nature of the phase which formed. β-Nitric Acid Trihydrate (NAT) was observed alongside a mixture of Nitric Acid Dihydrate (NAD) phases. It is not possible to determine whether NAT nucleates directly or is formed by a phase transition from NAD (likely requiring the presence of a mediating liquid phase). Regardless, these results demonstrate the possibility of forming NAT on laboratory timescales. In the polar stratosphere, sulfuric acid (present at several weight percent of the liquid under equilibrium conditions) could provide such a liquid phase. This study therefor provides insight into previous discrepancies between phases formed in the laboratory and those observed in the atmosphere. It also provides a basis for future studies into atmospheric nucleation of solid PSCs.

  20. P-CSCF's Algorithm for Solving NAT Traversal

    NASA Astrophysics Data System (ADS)

    Kim, Jung-Ho; Cho, Jae-Hyoung; Lee, Jae-Oh

    Many ways for efficient use of limited IP address of IPv4 are existed. The one of these ways is to construct the private network using Network Address Translator (NAT). NAT filtering rule makes network management easier. However, NAT Filtering rule makes NAT Traversal. Many solutions like Simple Traversal of UDP through NAT (STUN), Traversal Using Relay NAT (TURN) and Media Relay method exist. But these solutions require additional servers or devices. So, we suggest that P-CSCFs in the IP Multimedia Subsystem (IMS) change the packet's header and solve the NAT Traversal without any additional equipment.

  1. NAT8L (N-Acetyltransferase 8-Like) Accelerates Lipid Turnover and Increases Energy Expenditure in Brown Adipocytes*

    PubMed Central

    Pessentheiner, Ariane R.; Pelzmann, Helmut J.; Walenta, Evelyn; Schweiger, Martina; Groschner, Lukas N.; Graier, Wolfgang F.; Kolb, Dagmar; Uno, Kyosuke; Miyazaki, Toh; Nitta, Atsumi; Rieder, Dietmar; Prokesch, Andreas; Bogner-Strauss, Juliane G.

    2013-01-01

    NAT8L (N-acetyltransferase 8-like) catalyzes the formation of N-acetylaspartate (NAA) from acetyl-CoA and aspartate. In the brain, NAA delivers the acetate moiety for synthesis of acetyl-CoA that is further used for fatty acid generation. However, its function in other tissues remained elusive. Here, we show for the first time that Nat8l is highly expressed in adipose tissues and murine and human adipogenic cell lines and is localized in the mitochondria of brown adipocytes. Stable overexpression of Nat8l in immortalized brown adipogenic cells strongly increases glucose incorporation into neutral lipids, accompanied by increased lipolysis, indicating an accelerated lipid turnover. Additionally, mitochondrial mass and number as well as oxygen consumption are elevated upon Nat8l overexpression. Concordantly, expression levels of brown marker genes, such as Prdm16, Cidea, Pgc1α, Pparα, and particularly UCP1, are markedly elevated in these cells. Treatment with a PPARα antagonist indicates that the increase in UCP1 expression and oxygen consumption is PPARα-dependent. Nat8l knockdown in brown adipocytes has no impact on cellular triglyceride content, lipogenesis, or oxygen consumption, but lipolysis and brown marker gene expression are increased; the latter is also observed in BAT of Nat8l-KO mice. Interestingly, the expression of ATP-citrate lyase is increased in Nat8l-silenced adipocytes and BAT of Nat8l-KO mice, indicating a compensatory mechanism to sustain the acetyl-CoA pool once Nat8l levels are reduced. Taken together, our data show that Nat8l impacts on the brown adipogenic phenotype and suggests the existence of the NAT8L-driven NAA metabolism as a novel pathway to provide cytosolic acetyl-CoA for lipid synthesis in adipocytes. PMID:24155240

  2. Comparison of CYP1A2 and NAT2 Phenotypes between Black and White Smokers

    PubMed Central

    Muscat, Joshua E.; Pittman, Brian; Kleinman, Wayne; Lazarus, Philip; Stellman, Steven D.; Richie, John P.

    2008-01-01

    The lower incidence rate of transitional cell carcinoma of the urinary bladder in blacks than in whites may be due to racial differences in the catalytic activity of enzymes that metabolize carcinogenic arylamines in tobacco smoke. To examine this, we compared cytochrome P4501A2 (CYP1A2) and N-acetyltransferase-2 activities (NAT2) in black and white smokers using urinary caffeine metabolites as a probe for enzyme activity in a community-based study of 165 black and 183 white cigarette smokers. The paraxanthine (1,7-dimethylxanthine, 17X)/caffeine (trimethylxanthine, 137X) ratio or [17X + 1,7-dimethyluric acid (17U)]/137X ratio was used as an indicator of CYP1A2 activity. The 5-acetyl-amino-6-formylamino-3-methyluracil (AFMU)/1-methylxanthine (1X) ratio indicated NAT2 activity. The odds ratio for the slow NAT2 phenotype associated with black race was 0.4; 95% confidence intervals 0.2–0.7. The putative combined low risk phenotype (slow CYP1A2/rapid NAT2) was more common in blacks than in whites (25% vs. 15%, P<0.02). There were no significant racial differences in slow and rapid CYP1A2 phenotypes, and in the combined slow NAT2/rapid CYP1A2 phenotype. Age, education, cigarette smoking amount, body mass index, GSTM1 and GSTM3 genotypes were unrelated to CYP1A2 and NAT2 activity. Intake of cruciferous vegetables (primarily broccoli), red meat, carrots, grapefruit and onions predicted CYP1A2 activity either for all subjects or in race-specific analyses. Carrot and grapefruit consumption was related to NAT2 activity. Collectively, these results indicated that phenotypic differences in NAT2 alone or in combination with CYP1A2 might help explain the higher incidence rates of transitional cell bladder cancer in whites. PMID:18703023

  3. Comparison of CYP1A2 and NAT2 phenotypes between black and white smokers.

    PubMed

    Muscat, Joshua E; Pittman, Brian; Kleinman, Wayne; Lazarus, Philip; Stellman, Steven D; Richie, John P

    2008-10-01

    The lower incidence rate of transitional cell carcinoma of the urinary bladder in blacks than in whites may be due to racial differences in the catalytic activity of enzymes that metabolize carcinogenic arylamines in tobacco smoke. To examine this, we compared cytochrome P4501A2 (CYP1A2) and N-acetyltransferase-2 activities (NAT2) in black and white smokers using urinary caffeine metabolites as a probe for enzyme activity in a community-based study of 165 black and 183 white cigarette smokers. The paraxanthine (1,7-dimethylxanthine, 17X)/caffeine (trimethylxanthine, 137X) ratio or [17X+1,7-dimethyluric acid (17U)]/137X ratio was used as an indicator of CYP1A2 activity. The 5-acetyl-amino-6-formylamino-3-methyluracil (AFMU)/1-methylxanthine (1X) ratio indicated NAT2 activity. The odds ratio for the slow NAT2 phenotype associated with black race was 0.4; 95% confidence intervals 0.2-0.7. The putative combined low risk phenotype (slow CYP1A2/rapid NAT2) was more common in blacks than in whites (25% vs. 15%, P<0.02). There were no significant racial differences in slow and rapid CYP1A2 phenotypes, and in the combined slow NAT2/rapid CYP1A2 phenotype. Age, education, cigarette smoking amount, body mass index, GSTM1 and GSTM3 genotypes were unrelated to CYP1A2 and NAT2 activity. Intake of cruciferous vegetables (primarily broccoli), red meat, carrots, grapefruit and onions predicted CYP1A2 activity either for all subjects or in race-specific analyses. Carrot and grapefruit consumption was related to NAT2 activity. Collectively, these results indicated that phenotypic differences in NAT2 alone or in combination with CYP1A2 might help explain the higher incidence rates of transitional cell bladder cancer in whites. PMID:18703023

  4. Simultaneous determination of cefixime trihydrate and dicloxacillin sodium in pharmaceutical dosage form by reversed-phase high-performance liquid chromatography.

    PubMed

    Dhoka, Madhura V; Sandage, Shakuntala J; Dumbre, Snehal C

    2010-01-01

    A simple, precise, accurate, and sensitive RP-HPLC method for simultaneous determination of cefixime trihydrate and dicloxacillin sodium in combined tablet dosage form was developed and validated. Chromatographic separation of the two drugs was performed on a Purospher BDS C18 column (25 cm x 4.6 mm id, 5 microm particle size). The mobile phase methanol-0.01 M phosphate buffer (75 + 25, v/v), adjusted to pH 3 with glacial acetic acid, was delivered at a flow rate of 1.0 mL/min. Detection was performed at 227 nm. Separation was completed within 10 min. Calibration curves were linear with R2 between 0.99 to 1.0 over a concentration range of 2-10 microg/mL for cefixime trihydrate and 5-25 micromL for dicloxacillin sodium. The RSD for intraday and interday precision was < 2.0%. PMID:20480900

  5. NAT THE RAT - PUPIL'S BOOK. (TITLE SUPPLIED).

    ERIC Educational Resources Information Center

    ROJAS, PAULINE M.; AND OTHERS

    THE EXPERIMENTAL EDITION OF "NAT THE RAT" REPRESENTS LEVEL TWO OF THE "MIAMI LINGISTIC READERS" DESIGNED TO BE USED IN TEACHING BEGINNING READING TO PUPILS WHOSE PRESCHOOL LANGUAGE WAS OTHER THAN ENGLISH. THE FIVE MAJOR CHARACTERS IN THE STORY ARE INTRODUCED ON THE FIRST FIVE PAGES OF THE PUPILS' BOOK. ILLUSTRATIONS (BLACK AND WHITE) TO REINFORCE…

  6. Worldwide distribution of NAT2 diversity: Implications for NAT2 evolutionary history

    PubMed Central

    Sabbagh, Audrey; Langaney, André; Darlu, Pierre; Gérard, Nathalie; Krishnamoorthy, Rajagopal; Poloni, Estella S

    2008-01-01

    Background The N-acetyltransferase 2 (NAT2) gene plays a crucial role in the metabolism of many drugs and xenobiotics. As it represents a likely target of population-specific selection pressures, we fully sequenced the NAT2 coding region in 97 Mandenka individuals from Senegal, and compared these sequences to extant data on other African populations. The Mandenka data were further included in a worldwide dataset composed of 41 published population samples (6,727 individuals) from four continental regions that were adequately genotyped for all common NAT2 variants so as to provide further insights into the worldwide haplotype diversity and population structure at NAT2. Results The sequencing analysis of the NAT2 gene in the Mandenka sample revealed twelve polymorphic sites in the coding exon (two of which are newly identified mutations, C345T and C638T), defining 16 haplotypes. High diversity and no molecular signal of departure from neutrality were observed in this West African sample. On the basis of the worldwide genotyping survey dataset, we found a strong genetic structure differentiating East Asians from both Europeans and sub-Saharan Africans. This pattern could result from region- or population-specific selective pressures acting at this locus, as further suggested in the HapMap data by extremely high values of FST for a few SNPs positions in the NAT2 coding exon (T341C, C481T and A803G) in comparison to the empirical distribution of FST values accross the whole 400-kb region of the NAT gene family. Conclusion Patterns of sequence variation at NAT2 are consistent with selective neutrality in all sub-Saharan African populations investigated, whereas the high level of population differentiation between Europeans and East Asians inferred from SNPs could suggest population-specific selective pressures acting at this locus, probably caused by differences in diet or exposure to other environmental signals. PMID:18304320

  7. Real refractive indices of infrared-characterized nitric-acid/ice films: Implications for optical measurements of polar stratospheric clouds

    NASA Technical Reports Server (NTRS)

    Middlebrook, Ann M.; Berland, Brian S.; George, Steven M.; Tolbert, Margaret A.; Toon, Owen B.

    1994-01-01

    The infrared spectra of nitric-acid/ice films representative of polar stratospheric clouds (PSCs) were collected with simultaneous optical interference measurements to determine the real refractive indices at lambda = 632 nm. Ice and amphorous nitric-acid/ice films were prepared by condensation of water and nitric acid vapors onto a wedged Al2O3 substrate. The real refractive indices of these films were determined from the optical interference of a reflected helium-neon laser during film growth. The indices of the amphorous films varied smoothly from n = 1.30 for ice to n = 1.49 for nitric acid, similar to observations in previous work. We were unable to obtain the refractive index of crystlline films during adsorption because of optical scattering caused by surface roughness. Therefore crystlline nitric acid hydrate films were prepared by annealing amphorous nitric-acid/ice films. Further heating caused desorption of the crystalline hydrate films. During desorption, the refractive indices for ice, NAM (nitric acid monohydrate), alpha- and beta-NAT (nitric acid trihydrate) films were measured using the optical interference technique. In agreement with earlier data, the real refractive indices for ice and NAM determined in desorption were n = 1.30 +/- 0.01 and n = 1.53 +/- 0.03, respectively. The real refractive indices for alpha- and beta-NAT were found to be n = 1.51 +/- 0.01 and n greater than or equal to 1.46, respectively. Our measurements also suggest that the shape of crystalline nitric acid particles may depend on whether they nucleate from the liquid or by vapor deposition. If confirmed by future studies, this observation may provide a means of distinguishing the nucleation mechanism of crystalline PSCs.

  8. Balloon-Borne Measurements of Total Reactive Nitrogen, Nitric Acid, and Aerosol in the Cold Arctic Stratosphere

    NASA Technical Reports Server (NTRS)

    Kondo, Y.; Aimedieu, P.; Matthews, W. A.; Fahey, D. W.; Murcray, D. G.; Hofmann, D. J.; Johnston, P. V.; Iwasaka, Y.; Iwata, A.; Sheldon, W. R.

    1990-01-01

    Total reactive nitrogen (NO(Y)) between 15 and 29 km was measured for the first time on board a balloon within the Arctic cold vortex. Observations of HNO3, aerosol, and ozone were made by instruments on the same balloon gondola which was launched from Esrange, Sweden (68 deg N, 20 deg E) on January 23, 1989. The NO(y) mixing ratio was observed to increase very rapidly from 6 ppbv at 18 km altitude to a maximum of 21 ppbv at 21 km, forming a sharp layer with a thickness of about 2 km. A minimum in the NO(y) mixing ratio of 5 ppbv was found at 27 km. The measured HNO3 profile shows broad similarities to that of NO(y). This observation, together with the observed very low column amount of NO2, shows that NO(x) had been almost totally converted to HNO3, and that NO(y) was composed mainly of HNO3. The enhanced aerosol concentration between 19 and 22 km suggests that the maximum abundance of HNO3 trapped in the form of nitric acid trihydrate (NAT) was about 6 ppbv at 21 km. The sampled air parcels were highly supersaturated with respect to NAT. Although extensive denitrification throughout the stratosphere did not prevail, an indication of denitrification was found at altitudes of 27 and 22 km, and between 18 and 15 km.

  9. Recoil studies of photonuclear reactions on natCu, natAg, natTa, and 197Au at intermediate energies

    NASA Astrophysics Data System (ADS)

    Fujiwara, I.; Haba, H.; Matsumura, H.; Sakamoto, K.; Miyamoto, Y.; Oura, Y.; Shibata, S.; Furukawa, M.

    1999-01-01

    The recoil properties of nuclides produced in the photonuclear reactions on natCu, natAg, natTa, and 197Au induced by bremsstrahlung of end-point energies (E o) of 250 to 1000 MeV have been investigated using the thick-target thick-catcher method. The obtained mean ranges of produced nuclides smoothly increase with an increase of the mass difference (ΔA) between products and target, and show E 0-independence at E 0≥600 MeV, reflecting the limiting behavior above (3, 3) resonance region. The mean kinetic energies, T, deduced from the mean ranges show the following two components; (1) (γ, xn) products by giant-resonance and/or quasi-deuteron resonance absorption, (2) (γ, xnyp) products by mainly (3, 3) resonance absorption. Slightly rapid increase of T was found around ΔA=15, 18, 24, and 25 for natCu, natAg, natTa and 197Au, respectively, reflecting a change in mechanism. Kinematic properties of the product nuclei were calculated by using the PICA (Photon-Induced Intranuclear Cascade Analysis) code. The T calculated by the PICA code at E 0=400 MeV well reproduced the experimental results of natCu, but the same calculation for natAg, natTa, and 197Au gave lower mean kinetic energies than the experimental results.

  10. Recoil studies of photonuclear reactions on natCu, natAg, natTa, and 197Au at intermediate energies

    NASA Astrophysics Data System (ADS)

    Fujiwara, I.; Haba, H.; Matsumura, H.; Sakamoto, K.; Miyamoto, Y.; Oura, Y.; Shibata, S.; Furukawa, M.

    1999-01-01

    The recoil properties of nuclides produced in the photonuclear reactions on natCu, natAg, natTa, and 197Au induced by bremsstrahlung of end-point energies ( E o) of 250 to 1000 MeV have been investigated using the thick-target thick-catcher method. The obtained mean ranges of produced nuclides smoothly increase with an increase of the mass difference (ΔA) between products and target, and show E 0-independence at E 0≥600 MeV, reflecting the limiting behavior above (3, 3) resonance region. The mean kinetic energies, T, deduced from the mean ranges show the following two components; (1) (γ, xn) products by giant-resonance and/or quasi-deuteron resonance absorption, (2) (γ, xnyp) products by mainly (3, 3) resonance absorption. Slightly rapid increase of T was found around ΔA=15, 18, 24, and 25 for natCu, natAg, natTa and 197Au, respectively, reflecting a change in mechanism. Kinematic properties of the product nuclei were calculated by using the PICA (Photon-Induced Intranuclear Cascade Analysis) code. The T calculated by the PICA code at E 0=400 MeV well reproduced the experimental results of natCu, but the same calculation for natAg, natTa, and 197Au gave lower mean kinetic energies than the experimental results.

  11. Standardization of NAT for Blood-Borne Pathogens

    PubMed Central

    Baylis, Sally A.; Chudy, Michael; Nübling, C. Micha

    2015-01-01

    Summary Assays based on nucleic acid amplification technology (NAT) are increasingly used for screening of blood and for diagnosis or monitoring of patients. Both regulatory requirements for blood screening and international recommendations for the treatment of patients are based on common reference materials available globally for the standardization of NAT assays. World Health Organization International Standards (WHO ISs) and International Reference Panels (WHO IRPs) are primary reference materials. The characterization and manufacture of WHO reference materials as well as their evaluation is performed on behalf of the WHO by collaborating centers; their establishment is decided upon by the WHO Expert Committee on Biological Standardization (ECBS). The potency of the first WHO IS is defined by the ‘international unit’ (IU) which should be maintained upon replacement of the IS. The IU, unlike copy number or genome equivalent, is defined by the IS with a physical existence, is available worldwide, and allows traceability and comparability of results. The anticipated use of WHO ISs is the calibration of secondary standards or the validation of essential assay features, e.g. limit of detection. PMID:26557812

  12. IR spectroscopic investigations of amoxicillin trihydrate, included in the technological models sirup granules in ethylcellulose

    NASA Astrophysics Data System (ADS)

    Gasheva, L. M.; Kalinkova, G.; Minkov, E.; Krestev, V.

    1984-03-01

    Employing IR spectroscopy some technological models of amoxicillin trihydrate, included in ethyl-, methyl-, carboxymethyl- and methylhydroxyethyl-cellulose have been studied. Interactions were established only between amoxicillin trihydrate and ethylcellulose. The IR absorption spectra suggest a H-bonded antibiotic with hydroxyl groups in the ethylcellulose molecule. The IR spectral differences observed are not due to polymorphic transformation; this was proved by X-ray powder diffraction.

  13. Effect of arylamine acetyltransferase Nat3 gene knockout on N-acetylation in the mouse.

    PubMed

    Sugamori, K S; Brenneman, D; Wong, S; Gaedigk, A; Yu, V; Abramovici, H; Rozmahel, R; Grant, D M

    2007-07-01

    Arylamine N-acetyltransferases (NAT) catalyze the biotransformation of many important arylamine drugs and procarcinogens. NAT can either detoxify or activate procarcinogens, complicating the manner in which these enzymes may participate in enhancing or preventing toxic responses to particular agents. Mice possess three NAT isoenzymes: Nat1, Nat2, and Nat3. Whereas Nat1 and Nat2 can efficiently acetylate many arylamines, few substrates appear to be appreciably metabolized by Nat3. We generated a Nat3 knockout mouse strain and used it along with our double Nat1/2(-/-) knockout strain to further investigate the functional role of Nat3. Nat3(-/-) mice showed normal viability and reproductive capacity. Nat3 expression was very low in wild-type animals and completely undetectable in Nat3(-/-) mice. In contrast, greatly elevated expression of Nat3 transcript was observed in Nat1/2(-/-) mice. We used a transcribed marker polymorphism approach to establish that the increased expression of Nat3 in Nat1/2(-/-) mice is a positional artifact of insertion of the phosphoglycerate kinase-neomycin resistance cassette in place of the Nat1/Nat2 gene region and upstream of the intact Nat3 gene, rather than a biological compensatory mechanism. Despite the increase in Nat3 transcript, the N-acetylation of p-aminosalicylate, sulfamethazine, 2-aminofluorene, and 4-aminobiphenyl was undetectable either in vivo or in vitro in Nat1/2(-/-) animals. In parallel, no difference was observed in the in vivo clearance or in vitro metabolism of any of these substrates between wild-type and Nat3(-/-) mice. Thus, Nat3 is unlikely to play a significant role in the N-acetylation of arylamines either in wild-type mice or in mice lacking Nat1 and Nat2 activities. PMID:17403913

  14. Comparison of Procleix Ultrio Elite and Procleix Ultrio NAT Assays for Screening of Transfusion Transmitted Infections among Blood Donors in India

    PubMed Central

    Chaurasia, Rahul; Rout, Diptiranjan; Zaman, Shamsuz; Chatterjee, Kabita; Pandey, Hem Chandra; Maurya, Abhishek Kumar

    2016-01-01

    Background. Introduction of nucleic acid testing (NAT) has helped in decreasing window period donations, resulting in increased safety of blood supplies. NAT combines the advantages of direct and highly sequence-specific detection of viral genomes. We analysed the performance of newer Procleix Ultrio Elite (PUE) and Procleix Ultrio assay (PUA) for the screening of the viral markers in our donor population. Material and Methods. 10,015 donor samples were screened by routine immunoassays and both versions of NAT. NAT yields detected were subjected to viral load estimation and to other serological markers. Results. A total of 21 NAT yields were detected; three were positive by both NAT systems, whereas 18 samples were reactive by PUE only. NAT yields include 18 HBV and 3 HCV yields, of which 17 HBV yields were occult infections and 1 was window period (WP) infection. All 3 HCV yields were WP infections. No HIV-1/HIV-2 yield was found. Conclusion. Efficient target capture chemistry in the new TMA assay version significantly improved sensitivity. NAT is superior to serological immunoassays for screening of the viral markers; and the efficient target capture system in the newer TMA assay, namely, the PUE system, has significantly improved sensitivity over the earlier versions. PMID:26904124

  15. Association Between NAT2 Polymorphisms and Lung Cancer Susceptibility.

    PubMed

    Liu, Chang; Cui, Wei; Cong, Lin; Wang, Li; Ruan, Xinjian; Jia, Jia; Liu, Yanfang; Jia, Xiaoyan; Zhang, Xia

    2015-12-01

    To further investigate the association between NAT2 polymorphisms and lung cancer susceptibility.In terms of phenotypes, we investigated the acetylator status of NAT2 polymorphisms associated with lung cancer risk. Additionally, in view of genotypes, we mainly analyzed 5 single nucleotide polymorphisms (SNPs) in NAT2 gene, namely C282T, A803G, C481T, G590A, and G857A. Twenty-six eligible studies were included in our meta-analysis by searching PubMed, Embase, and CNKI databases. We used odds ratios (ORs) with corresponding 95% confidence intervals (CIs) to evaluate the susceptibility to lung cancer associated with NAT2 polymorphisms.Overall, based on phenotypes, the pooled ORs showed no significant association between NAT2 polymorphisms and lung cancer susceptibility. In the subgroup analyses by ethnicity and source of control, there was still no significant association. In terms of genotypes, overall, no obvious relationship was observed between NAT2 polymorphisms and lung cancer risk. But increased risk of lung cancer was found in association with NAT2 C282T polymorphism (TT vs. CC + TC: OR = 1.58, 95% CI = 1.11-2.25).Our meta-analysis demonstrates that TT genotype in NAT2 C282T polymorphism may be a risk factor for lung cancer susceptibility. Additionally, the acetylator status of 5 SNPs in NAT2 gene may not be associated with lung cancer risk. PMID:26656326

  16. Determination of NAT2 acetylation status in the Greenlandic population.

    PubMed

    Geller, Frank; Soborg, Bolette; Koch, Anders; Michelsen, Sascha Wilk; Bjorn-Mortensen, Karen; Carstensen, Lisbeth; Birch, Emilie; Nordholm, Anne Christine; Johansen, Marie Mila Broby; Børresen, Malene Landbo; Feenstra, Bjarke; Melbye, Mads

    2016-04-01

    N-acetyltransferase 2 (NAT2) is a well-studied phase II xenobiotic metabolizing enzyme relevant in drug metabolism and cancerogenesis. NAT2 activity is largely determined by genetic polymorphisms in the coding region of the corresponding gene. We investigated NAT2 acetylation status in 1556 individuals from Greenland based on four different single nucleotide polymorphism (SNP) panels and the tagging SNP rs1495741. There was good concordance between the NAT2 status inferred by the different SNP combinations. Overall, the fraction of slow acetylators was low with 17.5 % and varied depending on the degree of Inuit ancestry; in individuals with <50 % Inuit ancestry, we observed more than 25 % slow acetylators reflecting European ancestry. Greenland has a high incidence of tuberculosis, and individual dosing of isoniazid according to NAT2 status has been shown to improve treatment and reduce side effects. Our findings could be a first step in pharmacogenetics-based tuberculosis therapy in Greenland. PMID:25794903

  17. 16 CFR 1630.63 - Suspension of washing requirements for carpets and rugs with alumina trihydrate in the backing.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Alternatively the... carpets and rugs with alumina trihydrate in the backing. 1630.63 Section 1630.63 Commercial Practices... carpets and rugs with alumina trihydrate in the backing. (a)(1) The Standard for the Surface...

  18. 16 CFR 1630.63 - Suspension of washing requirements for carpets and rugs with alumina trihydrate in the backing.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Alternatively the... carpets and rugs with alumina trihydrate in the backing. 1630.63 Section 1630.63 Commercial Practices... carpets and rugs with alumina trihydrate in the backing. (a)(1) The Standard for the Surface...

  19. Genetic variation in N-acetyltransferase 1 (NAT1) and 2 (NAT2) and risk of non-Hodgkin lymphoma

    PubMed Central

    Morton, Lindsay M.; Schenk, Maryjean; Hein, David W.; Davis, Scott; Zahm, Shelia Hoar; Cozen, Wendy; Cerhan, James R.; Hartge, Patricia; Welch, Robert; Chanock, Stephen J.; Rothman, Nathaniel; Wang, Sophia S.

    2007-01-01

    Background Animal studies suggest that lymphomagenesis can be induced by exposure to carcinogenic aromatic and heterocyclic amines found in diet, cigarette smoke, and the environment, but human epidemiologic investigations of these exogenous exposures have yielded conflicting results. As part of our evaluation of the role of aromatic and heterocyclic amines, which are metabolized by N-acetyltransferase (NAT) enzymes, in the etiology of non-Hodgkin lymphoma (NHL), we examined NHL risk in relation to genetic variation in NAT1 and NAT2 and exposure to cigarette smoke and dietary heterocyclic amines and mutagens. Methods We genotyped ten common single nucleotide polymorphisms (SNPs) in NAT1 and NAT2 among 1136 cases and 922 controls from a population-based case–control study in four geographic areas of the US. Relative risk of NHL for NAT1 and NAT2 genotypes, NAT2 acetylation phenotype, and exposure to cigarette smoke and dietary heterocyclic amines and mutagens was estimated using odds ratios (ORs) and 95% confidence intervals (CIs) derived from unconditional logistic regression models. Results We observed increased risk of NHL among individuals with the NAT1*10/*10 genotype compared with individuals with other NAT1 genotypes (OR=1.60, 95% CI 1.04–2.46, p=0.03). We also observed increased NHL risk in a dose-dependent model among NAT2 intermediate- and rapid-acetylators in comparison with slow-acetylators, although only the trend was statistically significant (intermediate: OR=1.18, 95% CI 0.97–1.44, p=0.1; rapid: OR=1.43, 95% CI 0.97–2.14, p=0.07; p for linear trend=0.03). Compared with nonsmokers, NHL risk estimates for current cigarette smoking were increased only among NAT2 intermediate/rapid-acetylators (OR=2.44, 95% CI 1.15–5.20, p=0.02). Conclusions Our data provide evidence that NAT1 and NAT2 genotypes are associated with NHL risk and support a contributory role for carcinogenic aromatic and/or heterocyclic amines in the multi-factorial etiology of

  20. Mechanical Properties of a Calcium Dietary Supplement, Calcium Fumarate Trihydrate.

    PubMed

    Sun, Shijing; Henke, Sebastian; Wharmby, Michael T; Yeung, Hamish H-M; Li, Wei; Cheetham, Anthony K

    2015-12-01

    The mechanical properties of calcium fumarate trihydrate, a 1D coordination polymer considered for use as a calcium source for food and beverage enrichment, have been determined via nanoindentation and high-pressure X-ray diffraction with single crystals. The nanoindentation studies reveal that the elastic modulus (16.7-33.4 GPa, depending on crystallographic orientation), hardness (1.05-1.36 GPa), yield stress (0.70-0.90 GPa), and creep behavior (0.8-5.8 nm/s) can be rationalized in view of the anisotropic crystal structure; factors include the directionality of the inorganic Ca-O-Ca chain and hydrogen bonding, as well as the orientation of the fumarate ligands. High-pressure single-crystal X-ray diffraction studies show a bulk modulus of ∼ 20 GPa, which is indicative of elastic recovery intermediate between small molecule drug crystals and inorganic pharmaceutical ingredients. The combined use of nanoindentation and high-pressure X-ray diffraction techniques provides a complementary experimental approach for probing the critical mechanical properties related to tableting of these dietary supplements. PMID:26588472

  1. Single crystal growth and characterization of holmium tartrate trihydrate

    NASA Astrophysics Data System (ADS)

    Want, Basharat; Ahmad, Farooq; Kotru, P. N.

    2007-02-01

    The growth of holmium tartrate trihydrate (HTT) single crystals is achieved in organic (agar-agar) as well as in inorganic (silica) gels by single gel diffusion method. Results of the study on nucleation kinetics of crystals grown in silica gel are described. The crystals exhibit the morphological form of a tetragonal dipyramidal class with {0 0 1} and {1 1 1} as dominant faces. Elemental and thermogravimetric analysis (TGA) supplemented by energy dispersive analysis of X-rays (EDAX) support the suggested chemical formula of the grown crystals to be [Ho (C 4H 4O 6) (C 4H 5O 6)·3H 2O]. Single crystal X-ray diffraction (XRD) studies indicate that the crystals belong to tetragonal system with the cell parameters a=5.97 Å, c=36.09 Å, bearing the space group P4 1. Fourier transform infrared (FT-IR) spectroscopic study indicates the presence of tartrate ligands and suggests that one of the tartrate ions is singly ionized. TGA suggests that the material is thermally stable up to 220 °C.

  2. Simulations of the Vertical Redistribution of HNO3 by NAT or NAD PSCs: The Sensitivity to the Number of Cloud Particles Formed and the Cloud Lifetime

    NASA Technical Reports Server (NTRS)

    Jensen, Eric J.; Tabazadeh, Azadeh; Drdla, Katja; Toon, Owen B.; Gore, Warren J. (Technical Monitor)

    2000-01-01

    Recent satellite and in situ measurements have indicated that limited denitrification can occur in the Arctic stratosphere. In situ measurements from the SOLVE campaign indicate polar stratospheric clouds (PSCs) composed of small numbers (about 3 x 10^ -4 cm^-3) of 10-20 micron particles (probably NAT or NAD). These observations raise the issue of whether low number density NAT PSCs can substantially denitrify the air with reasonable cloud lifetimes. In this study, we use a one dimensional cloud model to investigate the verticle redistribution of HNO3 by NAT/NAD PSCs. The cloud formation is driven by a temperature oscillation which drops the temperature below the NAT/NAD formation threshold (about 195 K) for a few days. We assume that a small fraction of the available aerosols act as NAT nuclei when the saturation ratio of HNO3 over NAT(NAD) exceeds 10(l.5). The result is a cloud between about 16 and 20 km in the model, with NAT/NAD particle effective radii as large as about 10 microns (in agreement with the SOLVE data). We find that for typical cloud lifetimes of 2-3 days or less, the net depletion of HNO3 is no more than 1-2 ppbv, regardless of the NAT or NAD particle number density. Repeated passes of the air column through the cold pool build up the denitrification to 3-4 ppbv, and the cloud altitude steadily decreases due to the downward transport of nitric acid. Increasing the cloud lifetime results in considerably more effective denitrification, even with very low cloud particle number densities. As expected, the degree of denitrification by NAT clouds is much larger than that by NAD Clouds. Significant denitrification by NAD Clouds is only possible if the cloud lifetime is several days or more. The clouds also cause a local maximum HNO3 mixing ratio at cloud base where the cloud particles sublimate.

  3. Automated Triplex (HBV, HCV and HIV) NAT Assay Systems for Blood Screening in India

    PubMed Central

    2016-01-01

    This review is confined to triplex nucleic acid testing (NAT) assays to be used on fully automated platform. Around the world, these assays are being used at various transfusion medicine centres or blood banks to screen blood units for HBV, HCV and HIV. These assay systems can screen up to 1000 blood units for HBV, HCV and HIV simultaneously in a day. This area has been dominated by mainly two manufacturers: M/s Gen-Probe-Novartis and M/s Roche Molecular Systems. The triplex NAT assay systems of both manufacturers are licensed by United States Food and Drug Administration. There is not much awareness about the technology and procedures used in these assays. The main objective of this review is to create awareness about the technology and procedure of these assays. PMID:27042485

  4. Automated Triplex (HBV, HCV and HIV) NAT Assay Systems for Blood Screening in India.

    PubMed

    Rajput, Manoj Kumar

    2016-02-01

    This review is confined to triplex nucleic acid testing (NAT) assays to be used on fully automated platform. Around the world, these assays are being used at various transfusion medicine centres or blood banks to screen blood units for HBV, HCV and HIV. These assay systems can screen up to 1000 blood units for HBV, HCV and HIV simultaneously in a day. This area has been dominated by mainly two manufacturers: M/s Gen-Probe-Novartis and M/s Roche Molecular Systems. The triplex NAT assay systems of both manufacturers are licensed by United States Food and Drug Administration. There is not much awareness about the technology and procedures used in these assays. The main objective of this review is to create awareness about the technology and procedure of these assays. PMID:27042485

  5. The hydration number n of calcium dipicolinate trihydrate, CaDP center dot nH(2)O, and its effect on the IR spectra of sporulated Bacillus bacteria

    SciTech Connect

    Johnson, Timothy J.; Williams, Stephen D.; Valentine, Nancy B.; Su, Yin-Fong

    2010-05-26

    Previous results have shown a unique "quartet" of peaks in the infrared spectra of the sporulated phase of Bacillus bacteria, the four peaks being observed reproducibly for many different species of Bacillus endospores. We consistently observe peaks at 766, 725, 701, and 659 cm-1 and with the same relative amplitudes, as well as other spore peaks at 1441, 1277, 1015 cm-1. We have previously suggested that the peaks arise from calcium dipicolinate, not the conjugate acid. In this paper we conduct a theoretical and experimental study to show that the IR peaks not only arise from the calcium dipicolinate, a known spore component, but specifically the trihydrate salt, CaDP•3H2O. This is shown by calculating the absolute IR intensities of the lone dipicolinate dianion, the calcium salt, as well as the mono-, di- and tri-hydrate salts of calcium dipicolinate. The quartet peaks arise from the crystalline trihydrate salt as we verify both experimentally as well as using quantum chemistry methods. Using a method whereby the calculated intensities are not normalized, only the trihydrate spectrum shows low frequency modes (below 1000 cm-1, including the quartet) having intensities comparable to those of the pyridine ring. The vibrational modes in this part of the spectrum are associated with many internal coordinate motions including contributions from the Ca2+ counterion and the three waters including Ca-O-H bends, H2O-Ca-O torsions and O-C-O bends. Index Headings: Infrared, calcium dipicolinate, Bacillus, Bacteria, Endospores

  6. Cysteamine effects on somatostatin, catecholamines, pineal NAT and melatonin in rats

    SciTech Connect

    Webb, S.M.; Champney, T.H.; Steger, R.W.; Vaughan, M.K.; Reiter, R.J.

    1986-03-01

    The thiol reagent cysteamine was administered to adult male rats with the aim of investigating its effect on different neural and pineal components. As expected, immunoreactive somatostatin decreased in the median eminence (ME) (p less than 0.05) and gastric antrum (p less than 0.05) after cysteamine; however, no significant change was observed in the pineal IRS content after drug treatment. A decrease in norepinephrine was observed in the ME (p less than 0.001), hypothalamus (p less than 0.001) and pineal gland (p less than 0.05), together with a rise in ME (p less than 0.005) and hypothalamic dopamine (p less than 0.005) content; these results are consistent with a dopamine-beta-hydroxylase inhibiting effect of cysteamine. No effect was observed on hypothalamic serotonin and 5-hydroxyindole-acetic acid content. Pineal N-acetyltransferase (NAT) activity was significantly higher (p less than 0.05) after cysteamine than after saline, but no statistically significant effect was observed on pineal melatonin content. The mechanism involved in the NAT rise is presumably not related to the known stimulatory effect of norepinephrine, which fell after cysteamine. It is suggested that cysteamine may act at an intracellular level, inhibiting NAT degradation, an effect demonstrated in vitro and thought to be related to a thiol:disulfide exchange mechanism.

  7. Silica-alumina trihydrate filled epoxy castings resistant to arced SF.sub.6

    DOEpatents

    Chenoweth, Terrence E.; Yeoman, Frederick A.

    1978-01-01

    A cured, insulating, casting composition, having a coefficient of linear thermal expansion of below about 38 .times. 10.sup.-6 in./in./.degree. C and being resistant to arced sulfur hexafluoride gas, in contact with a metal surface in a sulfur hexafluoride gas environment, is made from hydantoin epoxy resin, anhydride curing agent and a filler combination of fused silica and alumina trihydrate.

  8. Evaluation of the Procleix Ultrio Plus ID NAT assay for detection of HIV 1, HBV and HCV in blood donors

    PubMed Central

    Makroo, Raj Nath; Chowdhry, Mohit; Bhatia, Aakanksha; Antony, Minimol

    2015-01-01

    Introduction: The Procleix Ultrio Plusassay is a new-generation qualitative in vitro nucleic acid amplification test used to screen for human immunodeficiency virus type 1 (HIV-1) RNA, hepatitis C virus (HCV) RNA and hepatitis B virus (HBV) DNA in blood donors. This study was performed to compare the Procleix Ultrio assay with the new-generation Procleix Ultrio Plus Nucleic Acid Test (NAT) assays. Materials and Methods: Ten thousand three hundred and two donor samples were run in parallel for ID NAT using the Procleix Ultrio and the Procleix Ultrio Plus assay. Simultaneously, enzyme-linked immunosorbent assay testing was performed on an EVOLIS Walk away System for HIV, HCV, HBsAg and anti-HBc. Reactive samples were confirmed using polymerase chain reaction. Results: In the 10,302 samples tested during the study period, we identified 15 NAT yields, and all these revealed HBV DNA in the discriminatory assays. Eight of these were exclusive yields from the Ultrio Plus assay and the remaining seven cases were determined as HBV NAT yield, both by the Procleix Ultrio as well as the Ultrio Plus assays, i.e. “Combined” yields. No HCV or HIV 1 yields were detected during the study period by either of two assays. Conclusion: With an overall yield rate of 1 in 687 and an exclusive yield rate of 1 in 1287, the Procleix Ultrio Plus assay proved to be highly sensitive in detecting occult HBV infections. PMID:25722569

  9. Evaluation of the Procleix Ultrio Elite Assay and the Panther-System for Individual NAT Screening of Blood, Hematopoietic Stem Cell, Tissue and Organ Donors

    PubMed Central

    Heim, Albert

    2016-01-01

    Summary Background The performance of the multiplex Procleix Ultrio Elite assay as individual donor nucleic acid test (ID-NAT) for the detection of HIV-1, HIV-2, HCV, and HBV was evaluated in a retrospective, single center study. Methods ID-NAT results of 21,181 blood donors, 984 tissue donors, 293 hematopoietic stem cell donors and 4 organ donors were reviewed in synopsis with results of serological screening and additional discriminatory and repetitive NAT in case of positive donors. Results Specificity of the initial Procleix Ultrio Elite assay was 99.98% and after discriminatory testing 100.00%. Initially invalid results were observed in 75 of 21,181 blood donors (0.35%) but 16 of 984 tissue donors (1.62%, p < 0.001) which included non-heart-beating (‘cadaveric’) donors. All these had valid negative ID-NAT results after repeated testing or testing of 1:5 diluted specimens in case of tissue donors. Occult hepatitis B (defined here as HBV DNAemia without HBsAg detection) was demonstrated by ID-NAT in two anti-HBc-positive tissue donors and suspected in two other tissue donors, where a definite diagnosis was not achieved due to the insufficient sample volumes available. Conclusion The Procleix Ultrio Elite assay proved to be specific, robust and rapid. Therefore, routine ID-NAT may also be feasible for organ and granulocyte donors.

  10. Arylamine N-acetyl Transferase (NAT) in the blue secretion of Telescopium telescopium: xenobiotic metabolizing enzyme as a biomarker for detection of environmental pollution.

    PubMed

    Gorain, Bapi; Chakraborty, Sumon; Pal, Murari Mohan; Sarkar, Ratul; Samanta, Samir Kumar; Karmakar, Sanmoy; Sen, Tuhinadri

    2014-01-01

    Telescopium telescopium, a marine mollusc collected from Sundarban mangrove, belongs to the largest mollusca phylum in the world and exudes a blue secretion when stimulated mechanically. The blue secretion was found to metabolize (preferentially) para-amino benzoic acid, a substrate for N-acetyl transferase (NAT), thereby indicating acetyl transferase like activity of the secretion. Attempts were also made to characterise bioactive fraction of the blue secretion and to further use this as a biomarker for monitoring of marine pollution. NAT like enzyme from marine mollusc is a potential candidate for detoxification of different harmful chemicals. A partially purified extract of blue secretion was obtained by fractional precipitation with (NH4)2SO4. From different fractions obtained by precipitation, the 0-30% fraction (30S) displayed NAT like activity (using para amino benzoic acid as a substrate with para nitrophenyl phosphate or acetyl coenzyme A as acetyl group donors). Maximum NAT like enzyme activity was attained at 25°C and at a pH of 6. The enzyme activity was found to be inhibited by 5 mM phenyl methyl sulfonyl fluoride. The divalent metal ions reduced NAT like activity of 30S. Moreover, Cu(2+) and Zn(2+) (at concentration of 1 mM) completely inhibited NAT activity. The thermal stability and bench-top stability studies were performed and it was found that the enzyme was stable at room temperature for more than 24 hours. Results from the present study further indicate that heavy metal content in blue secretion gradually decreased from pre-monsoon to post-monsoon season, which also corresponded to the change in NAT like activity. Therefore, this article stresses the importance of biomarker research for monitoring pollution. PMID:26034680

  11. PlantNATsDB: a comprehensive database of plant natural antisense transcripts

    PubMed Central

    Chen, Dijun; Yuan, Chunhui; Zhang, Jian; Zhang, Zhao; Bai, Lin; Meng, Yijun; Chen, Ling-Ling; Chen, Ming

    2012-01-01

    Natural antisense transcripts (NATs), as one type of regulatory RNAs, occur prevalently in plant genomes and play significant roles in physiological and pathological processes. Although their important biological functions have been reported widely, a comprehensive database is lacking up to now. Consequently, we constructed a plant NAT database (PlantNATsDB) involving approximately 2 million NAT pairs in 69 plant species. GO annotation and high-throughput small RNA sequencing data currently available were integrated to investigate the biological function of NATs. PlantNATsDB provides various user-friendly web interfaces to facilitate the presentation of NATs and an integrated, graphical network browser to display the complex networks formed by different NATs. Moreover, a ‘Gene Set Analysis’ module based on GO annotation was designed to dig out the statistical significantly overrepresented GO categories from the specific NAT network. PlantNATsDB is currently the most comprehensive resource of NATs in the plant kingdom, which can serve as a reference database to investigate the regulatory function of NATs. The PlantNATsDB is freely available at http://bis.zju.edu.cn/pnatdb/. PMID:22058132

  12. Age difference in pharmacokinetics of an amoxycillin trihydrate-15% formulation administered intramuscularly to ruminants.

    PubMed

    Nouws, J F; Guelen, P; Mevius, D; Driessens, F

    1986-10-01

    Intramuscular administration of an amoxycillin trihydrate-15% formulation to three groups of animals revealed in preruminant calves (age 3-4 weeks) significant higher plasma peak drug concentrations and shorter biological half-lives than in 5-month-old ruminant calves and dairy cows. Differences in pharmacokinetics were related to age-difference in drug absorption capability at the injection site regarding the formulation. PMID:3798717

  13. NAT2 genetic variations among South Indian populations.

    PubMed

    Lakkakula, Saikrishna; Mohan Pathapati, Ram; Chaubey, Gyaneshwer; Munirajan, Arasambattu Kannan; Lakkakula, Bhaskar Vks; Maram, Rajasekhar

    2014-01-01

    The N-acetyltransferases (NATs) are xenobiotic-metabolizing enzymes involved in the metabolism of drugs, environmental toxins and the aromatic amine carcinogens present in cigarette smoke. Genetic variations in NAT2 have long been recognized as the cause of variable enzymatic activity or stability, leading to slow or rapid acetylation. In the present study, we genotyped three single-nucleotide polymorphisms (SNPs) from the NAT2 gene (rs1799929, rs1799930 and rs1799931), using TaqMan allelic discrimination, among 212 individuals from six major South Indian populations and compared the results with other available Indian and worldwide data. All three of the markers followed Hardy-Weinberg equilibrium and were highly polymorphic in the studied populations. The constructed haplotypes showed a high level of heterozygosity. All of the populations in the present study commonly shared only four haplotypes out of the eight possible three-site haplotypes. The haplotypes exhibited fairly high frequencies across multiple populations, where three haplotypes were shared by all six populations with a cumulative frequency ranging from 88.2% (Madiga) to 97.0% (Balija). We also observed a tribal-specific haplotype. A strong linkage disequilibrium (LD) between rs1799929 and rs1799930 was consistent in all of the studied populations, with the exception of the Madiga. A comparison of the genomic regions 20-kb up- and downstream of rs1799930 in a large number of worldwide samples showed a strong LD of this SNP with another NAT2 SNP, rs1112005, among the majority of the populations. Moreover, our lifestyle test (hunter-gatherer versus agriculturist) in comparison with the NAT2 variant suggested that two of the studied populations (Balija and Madiga) have likely shifted their diet more recently. PMID:27081506

  14. Condensation of HNO3 on falling ice particles - Mechanism for denitrification of the polar stratosphere

    NASA Technical Reports Server (NTRS)

    Wofsy, S. C.; Salawitch, R. J.; Yatteau, J. H.; Mcelroy, M. B.; Gandrud, B. W.

    1990-01-01

    Ice particles created in polar stratospheric cooling events are predicted to descend into Type I PSCs and accrete a coating of nitric acid trihydrate (NAT) that inhibits evaporation. Coated particles efficiently strip HNO3 from the atmosphere, providing a mechanism for denitrification without significant dehydration. Coatings that disintegrate may release large particles of NAT that influence subsequent particle growth.

  15. Identification of N-Acetyltransferase 2 (NAT2) Transcription Start Sites and Quantitation of NAT2-specific mRNA in Human Tissues

    PubMed Central

    Husain, Anwar; Zhang, Xiaoyan; Doll, Mark A.; States, J. Christopher; Barker, David F.; Hein, David W.

    2007-01-01

    Human N-acetyltransferase 2 (NAT2) genetic polymorphism is associated with drug toxicity and/or carcinogenesis in various tissues. Knowledge of NAT2 gene structure and expression are critical for understanding these associations. Previous findings suggest that human NAT2 expression is highest in liver and gut, but expressed at functional levels in other tissues. A sensitive and specific TaqMan reverse transcriptase polymerase chain reaction (RT-PCR) assay with intron-spanning primers was developed and used, together with a second TaqMan RT-PCR assay based on amplification of a NAT2 open reading frame (ORF) exon segment, to measure NAT2 mRNA in 29 different human tissues. Cap-dependent amplification of mRNA 5′ termini and review of public database information was done to more precisely define the NAT2 promoter(s) and to validate the quantitative RT-PCR assay design. The great majority (40/41) of NAT2 liver cDNAs had 5′ termini between 8682 and 8752 nucleotides upstream of the NAT2 ORF exon, and 34/40 5′-termini were at the -8711 and -8716 adenines. All of 59 NAT2 cDNAs with 5′ termini in this vicinity, including 40 of the liver isolates and 19 cDNAs in public databases from liver and other sources, showed direct splicing to the ORF exon, with no other non-coding exon detected. NAT2 mRNA was highest in liver, small intestine and colon and readily detected in most other tissues albeit at much lower levels. NAT2 expression in diverse human tissues provides further mechanistic support underlying associations between NAT2 genetic polymorphism, drug toxicity and/or chemical carcinogenesis. PMID:17287389

  16. Improvements in algorithms for phenotype inference: the NAT2 example.

    PubMed

    Selinski, Silvia; Blaszkewicz, Meinolf; Ickstadt, Katja; Hengstler, Jan G; Golka, Klaus

    2014-02-01

    Numerous studies have analyzed the impact of N-acetyltransferase 2 (NAT2) polymorphisms on drug efficacy, side effects as well as cancer risk. Here, we present the state of the art of deriving haplotypes from polymorphisms and discuss the available software. PHASE v2.1 is currently considered a gold standard for NAT2 haplotype assignment. In vitro studies have shown that some slow acetylation genotypes confer reduced protein stability. This has been observed particularly for G191A, T341C and G590A. Substantial ethnic variations of the acetylation status have been described. Probably, upcoming agriculture and the resulting change in diet caused a selection pressure for slow acetylation. In recent years much research has been done to reduce the complexity of NAT2 genotyping. Deriving the haplotype from seven SNPs is still considered a gold standard. However, meanwhile several studies have shown that a two-SNP combination, C282T and T341C, results in a similarly good distinction in Caucasians. However, attempts to further reduce complexity to only one 'tagging SNP' (rs1495741) may lead to wrong predictions where phenotypically slow acetylators were genotyped as intermediate or rapid. Numerous studies have shown that slow NAT2 haplotypes are associated with increased urinary bladder cancer risk and increased risk of anti-tuberculosis drug-induced hepatotoxicity. A drawback of the current practice of solely discriminating slow, intermediate and rapid genotypes for phenotype inference is limited resolution of differences between slow acetylators. Future developments to differentiate between slow and ultra-slow genotypes may further improve individualized drug dosing and epidemiological studies of cancer risk. PMID:24524665

  17. Production cross section of At radionuclides from 7Li+natPb and 9Be+natTl reactions

    NASA Astrophysics Data System (ADS)

    Maiti, Moumita; Lahiri, Susanta

    2011-12-01

    Earlier we reported theoretical studies on the probable production of astatine radionuclides from 6,7Li- and 9Be-induced reactions on natural lead and thallium targets, respectively. The production of astatine radionuclides were investigated experimentally with two heavy-ion-induced reactions: 9Be + natTl and 7Li + natPb. Formation cross sections of the evaporation residues, 207,208,209,210At, produced in the (HI,xn) channel, were measured by the stacked-foil technique followed by off-line γ spectrometry at low incident energies (<50 MeV). Measured excitation functions were interpreted in terms of a compound nuclear reaction mechanism using Weisskopf-Ewing and Hauser-Feshbach models. Measured cross-section values are lower than the respective theoretical predictions.

  18. Microstructure-property relationships in alumina trihydrate filled poly (methyl methacrylate) composite materials

    NASA Astrophysics Data System (ADS)

    Zhang, Ruoyu

    2015-07-01

    The mechanical properties (Young's modulus and fracture toughness) of composite made from a poly (methyl methacrylate) (PMMA) matrix filled with alumina trihydrate(ATH) are reported. The experiments were performed using flexural tests and single edge notched bend (SENB) tests. The composites samples were tested at a range of filler volume fractions (34.7%, 39.4% and 44.4%) and mean filler diameters (8 pm, 15 pm and 25 pm). The data of Young's modulus agreed well with the results of Lielens model and finite element analysis (FEA) model.

  19. Persistent Water-Nitric Acid Condensate with Saturation Water Vapor Pressure Greater than That of Hexagonal Ice.

    PubMed

    Gao, Ru-Shan; Gierczak, Tomasz; Thornberry, Troy D; Rollins, Andrew W; Burkholder, James B; Telg, Hagen; Voigt, Christiane; Peter, Thomas; Fahey, David W

    2016-03-10

    A laboratory chilled mirror hygrometer (CMH), exposed to an airstream containing water vapor (H2O) and nitric acid (HNO3), has been used to demonstrate the existence of a persistent water-nitric acid condensate that has a saturation H2O vapor pressure greater than that of hexagonal ice (Ih). The condensate was routinely formed on the mirror by removing HNO3 from the airstream following the formation of an initial condensate on the mirror that resembled nitric acid trihydrate (NAT). Typical conditions for the formation of the persistent condensate were a H2O mixing ratio greater than 18 ppm, pressure of 128 hPa, and mirror temperature between 202 and 216 K. In steady-state operation, a CMH maintains a condensate of constant optical diffusivity on a mirror through control of only the mirror temperature. Maintaining the persistent condensate on the mirror required that the mirror temperature be below the H2O saturation temperature with respect to Ih by as much as 3 K, corresponding to up to 63% H2O supersaturation with respect to Ih. The condensate was observed to persist in steady state for up to 16 h. Compositional analysis of the condensate confirmed the co-condensation of H2O and HNO3 and thereby strongly supports the conclusion that the Ih supersaturation is due to residual HNO3 in the condensate. Although the exact structure or stoichiometry of the condensate could not be determined, other known stable phases of HNO3 and H2O are excluded as possible condensates. This persistent condensate, if it also forms in the upper tropical troposphere, might explain some of the high Ih supersaturations in cirrus and contrails that have been reported in the tropical tropopause region. PMID:26447682

  20. Proton and deuteron induced reactions on natGa: Experimental and calculated excitation functions

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Adam-Rebeles, R.; Tárkányi, F.; Takács, S.; Ditrói, F.

    2015-09-01

    Cross-sections for reactions on natGa, induced by protons (up to 65 MeV) and deuterons (up to 50 MeV), producing γ-emitting radionuclides with half-lives longer than 1 h were measured in a stacked-foil irradiation using thin Ga-Ni alloy (70-30%) targets electroplated on Cu or Au backings. Excitation functions for generation of 68,69Ge, 66,67,68,72Ga and 65,69mZn on natGa are discussed, relative to the monitor reactions natAl(d,x)24,22Na, natAl(p,x)24,22Na, natCu(p,x)62Zn and natNi(p,x)57Ni. The results are compared to our earlier measurements, the scarce literature values and to the results of the code TALYS 1.6 (online database TENDL-2014).

  1. Spectrophotometric Determination of Cefixime Trihydrate in Pharmaceutical Formulations Based on Ion-Pair Reaction with Bromophenol Blue.

    PubMed

    Keskar, Mrudul R; Jugade, Ravin M

    2015-01-01

    Cefixime trihydrate is a broad spectrum cephalosporin antibiotic, effective against gram-positive and gram-negative bacterial infections. Simple and rapid method has been developed for the determination of cefixime trihydrate in bulk and pharmaceutical formulations. This method was based on the formation of bluish-green ion-pair complex of cefixime trihydrate with bromophenol blue in dimethyl sulfoxide (DMSO)-acetonitrile medium. Different parameters were studied and optimized. A 2:1 complex was formed between the drug and reagent almost instantaneously at room temperature which has λmax of 610 nm. Under optimum conditions, calibration curve was found to be linear over the range of 10-130 μg mL(-1). The method was subjected to analytical quality control. The limit of detection was found to be 1.08 μg mL(-1). Recovery studies and interference studies were carried out. The proposed method was successfully applied to the determination of cefixime trihydrate in bulk and pharmaceutical formulations with high precision and accuracy. PMID:26279621

  2. Spectrophotometric Determination of Cefixime Trihydrate in Pharmaceutical Formulations Based on Ion-Pair Reaction with Bromophenol Blue

    PubMed Central

    Keskar, Mrudul R; Jugade, Ravin M

    2015-01-01

    Cefixime trihydrate is a broad spectrum cephalosporin antibiotic, effective against gram-positive and gram-negative bacterial infections. Simple and rapid method has been developed for the determination of cefixime trihydrate in bulk and pharmaceutical formulations. This method was based on the formation of bluish-green ion-pair complex of cefixime trihydrate with bromophenol blue in dimethyl sulfoxide (DMSO)–acetonitrile medium. Different parameters were studied and optimized. A 2:1 complex was formed between the drug and reagent almost instantaneously at room temperature which has λmax of 610 nm. Under optimum conditions, calibration curve was found to be linear over the range of 10–130 μg mL−1. The method was subjected to analytical quality control. The limit of detection was found to be 1.08 μg mL−1. Recovery studies and interference studies were carried out. The proposed method was successfully applied to the determination of cefixime trihydrate in bulk and pharmaceutical formulations with high precision and accuracy. PMID:26279621

  3. Global analysis of cis-natural antisense transcripts and their heat-responsive nat-siRNAs in Brassica rapa

    PubMed Central

    2013-01-01

    Background Brassica rapa includes several important leaf vegetable crops whose production is often damaged by high temperature. Cis-natural antisense transcripts (cis-NATs) and cis-NATs-derived small interfering RNAs (nat-siRNAs) play important roles in plant development and stress responses. However, genome-wide cis-NATs in B. rapa are not known. The NATs and nat-siRNAs that respond to heat stress have never been well studied in B. rapa. Here, we took advantage of RNA-seq and small RNA (sRNA) deep sequencing technology to identify cis-NATs and heat responsive nat-siRNAs in B. rapa. Results Analyses of four RNA sequencing datasets revealed 1031 cis-NATs B. rapa ssp. chinensis cv Wut and B. rapa ssp. pekinensis cv. Bre. Based on sequence homology between Arabidopsis thaliana and B. rapa, 303 conserved cis-NATs in B. rapa were found to correspond to 280 cis-NATs in Arabidopsis; the remaining 728 novel cis-NATs were identified as Brassica-specific ones. Using six sRNA libraries, 4846 nat-siRNAs derived from 150 cis-NATs were detected. Differential expression analysis revealed that nat-siRNAs derived from 12 cis-NATs were responsive to heat stress, and most of them showed strand bias. Real-time PCR indicated that most of the transcripts generating heat-responsive nat-siRNAs were upregulated under heat stress, while the transcripts from the opposite strands of the same loci were downregulated. Conclusions Our results provide the first subsets of genome-wide cis-NATs and heat-responsive nat-siRNAs in B. rapa; these sRNAs are potentially useful for the genetic improvement of heat tolerance in B. rapa and other crops. PMID:24320882

  4. The Infrared Spectra of Bacillus Bacteria Part II: Sporulated Bacillus-the Effect of Vegetative Cells and Contributions of Calcium Dipicolinate Trihydrate, CaDP•3H2O

    SciTech Connect

    Johnson, Timothy J.; Williams, Stephen D.; Valentine, Nancy B.; Su, Yin-Fong

    2009-08-01

    Our previous paper showed that certain IR peaks, e.g. the peak at 1739 cm-1, are due to varying (trace) amounts of vegetative cells amongst the Bacillus spores and that these and other vegetative bands are associated with lipid-soluble compounds, likely phosphatidyl glycerol or phosphatidyl ethanolamine. This work investigates the infrared spectra of eight different sporulated Bacillus bacteria. For the endospores it is observed that peaks at 1441, 1277, 1015 cm-1 along with a distinct quartet of peaks at 766, 725, 701, and 659 cm-1 are clearly associated with calcium dipicolinate trihydrate, CaDP•3H2O. It is emphasized that the spore peaks, especially the quartet, arise from the calcium dipicolinate trihydrate and not from dipicolinic acid or other dipicolinate hydrate salts. The CaDP•3H2O vibrational peaks and the effects of hydration are studied using quantum chemistry in the PQS software package. The quartet is associated with many modes including contributions from the Ca2+ counterion and hydration waters including Ca-O-H bends, H2O-Ca-O torsions and O-C-O bends. The 1441 and 1015 cm-1 modes are planar pyridine modes with the 1441 mode primarily a ring C-N stretch and the 1015 mode primarily a ring C-C stretch.

  5. Low temperature structural phase transition in hafnium and zirconium tetrafluoride trihydrates

    NASA Astrophysics Data System (ADS)

    Dey, S. K.; Dey, C. C.; Saha, S.

    2016-04-01

    From time-differential perturbed angular correlation (TDPAC) measurements, the monoclinic and triclinic crystal structures in hafnium and zirconium tetrafluoride trihydrates are found to be present simultaneously in both the compounds. From previous TDPAC and XRD investigations, a monoclinic crystal structure for HfF4·3H2O but, for its analogues zirconium compound, a triclinic structure was reported. Contrary to earlier reports, the triclinic fraction in HfF4·3H2O is found to be maximum (80%) at room temperature. In fact, the triclinic crystal structure of HfF4·3H2O is reported here which was not known prior to this report. In ZrF4·3H2O, a strong signal (80-90%) for the triclinic structure is found at room temperature while the monoclinic fraction appears as a weak signal (10-15%). Structural phase transitions in these trihydrate compounds have been observed in the temperature range 298-333 K.

  6. Induction of micronuclei in rat bone marrow after chronic exposure to lead acetate trihydrate.

    PubMed

    Alghazal, M A; Sutiaková, I; Kovalkovicová, N; Legáth, J; Falis, M; Pistl, J; Sabo, R; Benová, K; Sabová, L; Váczi, P

    2008-10-01

    Lead increasingly contributes to pollution of the environment and may play a role in the development of adverse effects in the human and animal body. Data concerning its mutagenic, clastogenic, and carcinogenic properties have been conflicting. In this study, we evaluated the frequency of micronuclei in bone marrow erythrocytes of rats treated with lead acetate trihydrate. Outbred Wistar rats were exposed to a daily dose of 100 mg/L drinking water for 125 days. The mean value of the total number of micronuclei observed in polychromatic erythrocytes of female rats was significantly higher than that found in the control group (13.375 +/- 2.722 against 9.625 +/- 3.204 micronuclei/1000 cells; P = 0.024 in ANOVA). In exposed female animals, no significant reduction of the ratio of polychromatic to normochromatic erythrocytes was observed (0.990 +/- 0.228 against 1.208 +/- 0.195; P = 0.060 in ANOVA). The effects of lead acetate trihydrate in male rats are both cytotoxic and genotoxic because of a decrease in ratio of polychromatic to normochromatic erythrocytes (0.715 +/- 0.431 against 1.343 +/- 0.306; P = 0.023, ANOVA followed by Tukey test) and an increase in frequency of micronucleated polychromatic erythrocytes (24.167 +/- 7.859 against 4.0 +/- 4.528 micronuclei/1000 cells; P < or = 0.001, ANOVA followed by Tukey test), respectively. PMID:19106125

  7. The NatA Acetyltransferase Couples Sup35 Prion Complexes to the [PSI+] Phenotype

    PubMed Central

    Pezza, John A.; Langseth, Sara X.; Raupp Yamamoto, Rochele; Doris, Stephen M.; Ulin, Samuel P.; Salomon, Arthur R.

    2009-01-01

    Protein-only (prion) epigenetic elements confer unique phenotypes by adopting alternate conformations that specify new traits. Given the conformational flexibility of prion proteins, protein-only inheritance requires efficient self-replication of the underlying conformation. To explore the cellular regulation of conformational self-replication and its phenotypic effects, we analyzed genetic interactions between [PSI+], a prion form of the S. cerevisiae Sup35 protein (Sup35[PSI+]), and the three Nα-acetyltransferases, NatA, NatB, and NatC, which collectively modify ∼50% of yeast proteins. Although prion propagation proceeds normally in the absence of NatB or NatC, the [PSI+] phenotype is reversed in strains lacking NatA. Despite this change in phenotype, [PSI+] NatA mutants continue to propagate heritable Sup35[PSI+]. This uncoupling of protein state and phenotype does not arise through a decrease in the number or activity of prion templates (propagons) or through an increase in soluble Sup35. Rather, NatA null strains are specifically impaired in establishing the translation termination defect that normally accompanies Sup35 incorporation into prion complexes. The NatA effect cannot be explained by the modification of known components of the [PSI+] prion cycle including Sup35; thus, novel acetylated cellular factors must act to establish and maintain the tight link between Sup35[PSI+] complexes and their phenotypic effects. PMID:19073888

  8. Neutron emission asymmetries from linearly polarized γ rays on ^natCd, ^natSn, and ^181Ta

    NASA Astrophysics Data System (ADS)

    Clarke Smith, W.; Feldman, Gerald

    2011-10-01

    Azimuthal asymmetries in neutron yields produced by bombarding targets with linearly polarized photons via (γ,n), (γ,2n), and (γ,f) reactions are being investigated as a possible means of identifying various nuclear isotopes. The High Intensity γ-ray Source (HIγS) at Duke University provides nearly monochromatic, circularly or linearly polarized γ rays with high intensity by Compton backscattering free-electron-laser photons from stored electrons. Linearly polarized γ rays produced by HIγS were incident on ^natCd, ^natSn, and ^181Ta targets at six energies Eγ between 11.0 and 15.5 MeV and emitted neutrons were detected both parallel and perpendicular to the plane of polarization by an array of 18 liquid-scintillator detectors at angles in the range θ=55^o--142^o. Detected neutrons were distinguished from Compton scattered photons by pulse-shape-discrimination and timing cuts, and their energies (En) were determined using time-of-flight information over a 0.5 m flight path. The characteristic plots of Rn, the ratio of neutron counts parallel to neutron counts perpendicular to the plane of the incident γ-ray polarization, against En were constructed for each value of Eγ and θ and then compared to those for other targets studied at HIγS, including fissile nuclei ^235U and ^238U.

  9. A Study Guide for Stephen B. Oates' "The Fires of Jubilee: Nat Turner's Fierce Rebellion"

    ERIC Educational Resources Information Center

    Briley, Ron

    2006-01-01

    This document is a study guide for Stephen B. Oates biography of Nat Turner, "The Fires of Jubilee." The book is a practical reading vehicle for introducing Nat Turner to secondary students in grades 11 and 12. Oates divides his work into four parts, which could provide the basis for four reading assignments, although the sections are not of equal…

  10. NAT10, a nucleolar protein, localizes to the midbody and regulates cytokinesis and acetylation of microtubules

    SciTech Connect

    Shen, Qi; Zheng, Xingzheng; McNutt, Michael A.; Guang, Lizhao; Sun, Ying; Wang, Jiaochen; Gong, Yilei; Hou, Lin; Zhang, Bo

    2009-06-10

    The midbody is a structural organelle formed in late phase mitosis which is responsible for completion of cytokinesis. Although various kinds of proteins have been found to distribute or immigrate to this organelle, their functions have still not been completely worked out. In this study, we demonstrated that NAT10 (N-acetyltransferase 10, NAT10) is not only predominantly distributed in the nucleolus in interphase, but is also concentrated in the mitotic midbody during telophase. The domain in N-terminal residues 549-834 of NAT10 specifically mediated its subcellular localization. Treatment with genotoxic agents or irradiation increased concentration of NAT10 in both the nucleolus and midbody. Moreover, DNA damage induced increase of NAT10 in the midbody apparently accompanied by in situ elevation of the level of acetylated {alpha}-tubulin, suggesting that it plays a role in maintaining or enhancing stability of {alpha}-tubulin. The depletion of NAT10 induced defects in nucleolar assembly, cytokinesis and decreased acetylated {alpha}-tubulin, leading to G2/M cell cycle arrest or delay of mitotic exit. In addition, over-expression of NAT10 was found in a variety of soft tissue sarcomas, and correlated with tumor histological grading. These results indicate that NAT10 may play an important role in cell division through facilitating reformation of the nucleolus and midbody in the late phase of cell mitosis, and stabilization of microtubules.

  11. Metabolic activation and analgesic effect of flupirtine in healthy subjects, influence of the polymorphic NAT2, UGT1A1 and GSTP1

    PubMed Central

    Siegmund, Werner; Modess, Christiane; Scheuch, Eberhard; Methling, Karen; Keiser, Markus; Nassif, Ali; Rosskopf, Dieter; Bednarski, Patrick J; Borlak, Jürgen; Terhaag, Bernd

    2015-01-01

    Aims The rare association of flupirtine with liver injury is most likely caused by reactive quinone diimines and their oxidative formation may be influenced by the activities of N-acetyltransferases (NAT) that conjugate the less toxic metabolite D13223, and by glucuronosyltransferases (UGT) and glutathione S-transferases (GST) that generate stable terminal glucuronides and mercapturic acid derivatives, respectively. The influence of genetic polymorphisms of NAT2, UGT1A1 and GSTP1 on generation of the terminal mercapturic acid derivatives and analgesic effects was evaluated to identify potential genetic risk factors for hepatotoxicity of flupirtine. Methods Metabolic disposition of flupirtine was measured after intravenous administration (100 mg), after swallowing an immediate-release (IR) tablet (100 mg) and after repeated administration of modified release (MR) tablets (400 mg once daily 8 days) in 36 selected healthy subjects. Analgesic effects were measured using pain models (delayed onset of muscle soreness, electric pain). Results Flupirtine IR was rapidly but incompletely absorbed (∼72%). Repeated administration of flupirtine MR showed lower bioavailability (∼60%). Approximately 12% of bioavailable flupirtine IR and 8% of bioavailable flupiritine MR was eliminated as mercapturic acid derivatives into the urine independent of the UGT1A1, NAT2 and GSTP1 genotype. Carriers of variant GSTP1 alleles showed lower bioavailability but increased intestinal secretion of flupirtine and increased efficiency in experimental pain. Flupirtine was not a substrate for ABCB1 and ABCC2. Conclusions Formation of mercapturic acid derivatives is a major elimination route for flupirtine in man. However, the theoretically toxic pathway is not influenced by the frequent polymorphisms of UGT1A1, NAT2 and GSTP1. PMID:25264565

  12. A new compound in kidney stones? Powder X-ray diffraction study of calcium glycinate trihydrate.

    PubMed

    Le Bail, Armel; Daudon, Michel; Bazin, Dominique

    2013-07-01

    The present identification of a new compound in kidney stones is relevant in clinical practice. Here, poly[[di-μ-aqua-bis(glycinato-κ(2)N,O)calcium(II)] monohydrate], {[Ca(C2H4NO2)2(H2O)2]·H2O}n, has been identified in a possible kidney concretion, although it could be a 'false calculus' associated with Munchausen syndrome. The crystal packing is characterized by an infinite zigzag chain of Ca atoms in [Ca(OW)4O2N2] (OW is a water O atom) square antiprisms, sharing edges formed by water molecules. An uncoordinated water molecule interconnects the parallel chains in a three-dimensional hydrogen-bonding scheme. Similarities between the trihydrate and the monohydrate are described. PMID:23832032

  13. 76 FR 72950 - Draft Guidance for Industry: Use of Nucleic Acid Tests on Pooled and Individual Samples From...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-11-28

    ... (HBV) deoxyribonucleic acid (DNA) and recommendations for product testing and disposition, donor...- licensed NAT to screen blood donors for HBV DNA. FDA is also providing these blood establishments...

  14. EEG markers for characterizing anomalous activities of cerebral neurons in NAT (neuronal activity topography) method.

    PubMed

    Musha, Toshimitsu; Matsuzaki, Haruyasu; Kobayashi, Yohei; Okamoto, Yoshiwo; Tanaka, Mieko; Asada, Takashi

    2013-08-01

    A pair of markers, sNAT and vNAT, is derived from the electroencephalogram (EEG) power spectra (PS) recorded for 5 min with 21 electrodes (4-20 Hz) arranged according to the 10-20 standard. These markers form a new diagnosis tool "NAT" aiming at characterizing various brain disorders. Each signal sequence is divided into segments of 0.64 s and its discrete PS consists of eleven frequency components from 4.68 (3 × 1.56) Hz through 20.34 (13 × 1.56) Hz. PS is normalized to its mean and the bias of PS components on each frequency component across the 21 signal channels is reset to zero. The marker sNAT consists of ten frequency components on 21 channels, characterizing neuronal hyperactivity or hypoactivity as compared with NLc (normal controls). The marker vNAT consists of ten ratios between adjacent PS components denoting the over- or undersynchrony of collective neuronal activities as compared with NLc. The likelihood of a test subject to a specified brain disease is defined in terms of the normalized distance to the template NAT state of the disease in the NAT space. Separation of MCI-AD patients (developing AD in 12-18 months) from NLc is made with a false alarm rate of 15%. Locations with neuronal hypoactivity and undersynchrony of AD patients agree with locations of rCBF reduction measured by SPECT. The 2-D diagram composed of the binary likelihoods between ADc and NLc in the two representations of sNAT and vNAT enables tracing the NAT state of a test subject approaching the AD area, and the follow-up of the treatment effects. PMID:23559020

  15. Infrared spectra of solid films formed from vapors containing water and nitric acid

    NASA Technical Reports Server (NTRS)

    Smith, Roland H.; Leu, Ming-Taun; Keyser, Leon F.

    1991-01-01

    The paper presents infrared spectra recorded at 188 K for crystalline mono- and trihydrates of nitric acid formed by vapor deposition, along with spectra of fully deuterated forms of these compounds. The spectra are interpreted in terms of the known ionic structures of the hydrates and the known spectra of oxonium and nitrate ions. Two additional species were identified: a molecular hydrogen-bonded HNO3-H2O complex, stable only at temperatures below 120 or 150 K, and a substance considered to be a crystalline mixtgure of trihydrate and ice. The relevance of these findings to the stratospheric ozone hole problem is discussed.

  16. Partial Least-Squares and Linear Support Vector Regression Chemometric Methods for Simultaneous Determination of Amoxicillin Trihydrate and Dicloxacillin Sodium in the Presence of Their Common Impurity.

    PubMed

    Naguib, Ibrahim A; Abdelaleem, Eglal A; Zaazaa, Hala E; Hussein, Essraa A

    2016-07-01

    Two multivariate chemometric models, namely, partial least-squares regression (PLSR) and linear support vector regression (SVR), are presented for the analysis of amoxicillin trihydrate and dicloxacillin sodium in the presence of their common impurity (6-aminopenicillanic acid) in raw materials and in pharmaceutical dosage form via handling UV spectral data and making a modest comparison between the two models, highlighting the advantages and limitations of each. For optimum analysis, a three-factor, four-level experimental design was established, resulting in a training set of 16 mixtures containing different ratios of interfering species. To validate the prediction ability of the suggested models, an independent test set consisting of eight mixtures was used. The presented results show the ability of the two proposed models to determine the two drugs simultaneously in the presence of small levels of the common impurity with high accuracy and selectivity. The analysis results of the dosage form were statistically compared to a reported HPLC method, with no significant difference regarding accuracy and precision, indicating the ability of the suggested multivariate calibration models to be reliable and suitable for routine analysis of the drug product. Compared to the PLSR model, the SVR model gives more accurate results with a lower prediction error, as well as high generalization ability; however, the PLSR model is easy to handle and fast to optimize. PMID:27305461

  17. Effect of NAT2 gene polymorphism on bladder cancer risk in Slovak population.

    PubMed

    Klimčáková, Lucia; Habalová, Viera; Sivoňová, Monika; Nagy, Vincent; Šalagovič, Ján; Židzik, Jozef

    2011-02-01

    N-acetyltransferase 2 (NAT2) is phase II enzyme with major roles in catalyzing the detoxification of aromatic amines, which are known risk factors for bladder cancer, and are ubiquitously present in the environment. We assessed the association between common polymorphisms in NAT2 gene and the risk of bladder cancer in 90 Slovak patients and 274 ethnicity-matched healthy controls. Effect modifications by smoking, age and gender were also evaluated. Overall, NAT2 slow acetylation was associated with significantly increased risk of bladder cancer (OR = 1.90; 95% CI, 1.15-3.16). In stratified analyses by age and gender, the elevated risk conferred by slow acetylator genotype was evident in older individuals (OR = 3.55; 95% CI, 1.77-7.35) and males (OR = 4.65; 95% CI, 1.68-16.10), with further increasing in NAT2*5B/*6A genotype carriers. Smoking was confirmed to be important risk factor, moreover, the risk was markedly increased in smokers with NAT2 slow acetylator genotype, and NAT2*5B/*6A carriers especially. In summary, these findings are consistent with previous literature suggesting that individual susceptibility to bladder cancer may be modulated by NAT2 polymorphisms, particularly in interaction with relevant environmental exposures such as smoking. PMID:20568013

  18. Dehydration of Uranyl Nitrate Hexahydrate to Uranyl Nitrate Trihydrate under Ambient Conditions as Observed via Dynamic Infrared Reflectance Spectroscopy

    SciTech Connect

    Johnson, Timothy J.; Sweet, Lucas E.; Meier, David E.; Mausolf, Edward J.; Kim, Eunja; Weck, Philippe F.; Buck, Edgar C.; McNamara, Bruce K.

    2015-05-22

    the hexahydrate [UO2(NO3)2(H2O)6] (UNH) and the trihydrate [UO2(NO3)2(H2O)3] (UNT) forms. Their stabilities depend on both relative humidity and temperature. Both phases have previously been studied by infrared transmission spectroscopy, but the data were limited by both instrumental resolution and the ability to prepare the samples as pellets without desiccating them. We report time-resolved infrared (IR) measurements using an integrating sphere that allow us to observe the transformation from the hexahydrate to the trihydrate simply by flowing dry nitrogen gas over the sample. Hexahydrate samples were prepared and confirmed via known XRD patterns, then measured in reflectance mode. The hexahydrate has a distinct uranyl asymmetric stretch band at 949.0 cm-1 that shifts to shorter wavelengths and broadens as the sample dehydrates and recrystallizes to the trihydrate, first as a blue edge shoulder but ultimately resulting in a doublet band with reflectance peaks at 966 and 957 cm-1. The data are consistent with transformation from UNH to UNT since UNT has two non-equivalent UO22+ sites. The dehydration of UO2(NO3)2(H2O)6 to UO2(NO3)2(H2O)3 is both a morphological and structural change that has the lustrous lime green crystals changing to the dull greenish yellow of the trihydrate. Crystal structures and phase transformation were confirmed theoretically using DFT calculations and experimentally via microscopy methods. Both methods showed a transformation with two distinct sites for the uranyl cation in the trihydrate, as opposed to a single crystallographic site in the hexahydrate.

  19. Formation of nitric acid hydrates - A chemical equilibrium approach

    NASA Technical Reports Server (NTRS)

    Smith, Roland H.

    1990-01-01

    Published data are used to calculate equilibrium constants for reactions of the formation of nitric acid hydrates over the temperature range 190 to 205 K. Standard enthalpies of formation and standard entropies are calculated for the tri- and mono-hydrates. These are shown to be in reasonable agreement with earlier calorimetric measurements. The formation of nitric acid trihydrate in the polar stratosphere is discussed in terms of these equilibrium constants.

  20. Investigations of natTi(d,x)48V nuclear reactions for beam monitoring purposes

    NASA Astrophysics Data System (ADS)

    Khandaker, Mayeen Uddin; Haba, Hiromitsu; Kanaya, Jumpei; Otuka, Naohiko; Kassim, Hasan Abu; Amin, Yusoff Mohd

    2013-05-01

    We investigated the natTi(d,x)48V reaction cross-sections by using a stacked-foil activation technique in combination with HPGe γ-ray spectrometry at the AVF cyclotron facility of the RIKEN RI Beam Factory, Wako, Japan. An overall good agreement is found between the measured data and the literature ones, whereas partial agreement is obtained with the theoretical data extracted from the TENDL-2011 library provided by the TALYS model calculations. Measured cross-sections of natTi(d,x)48V reactions find significance in monitoring of deuteron beam parameters from threshold to 50 MeV. Furthermore, IAEA recommended cross-sections of natTi(d,x)48V reaction has been verified here, and found a very good agreement. Additionally, measured cross-sections of the natTi(d,x)48V reactions find significance in various practical applications including nuclear medicine.

  1. Expression of NAT2 in immune system cells and the relation of NAT2 gene polymorphisms in the anti-tuberculosis therapy in Mexican mestizo population.

    PubMed

    Salazar-González, R; Gómez, R; Romano-Moreno, S; Medellín-Garibay, S; Núñez-Ruíz, A; Magaña-Aquino, M; Milán-Segovia, R C; Portales-Pérez, D P

    2014-12-01

    Arylamine N-acetyltransferase 2 (NAT2) metabolizes isoniazid (INH) and Single Nucleotide Polymorphisms (SNP) responsible for its activity has been reported. The aim of this study in the Mexican mestizo population was to evaluate NAT2 expression at the protein level in immune cells, as well as the distribution and frequency of six NAT2 SNPs and their association with anti-TB therapy, by measuring the plasma levels of INH and Acetyl-INH (AcINH). We performed genotyping assays of NAT2 SNPs in 40 TB patients and 121 healthy volunteers by real-time PCR. A method for detecting NAT2 in immune cells using flow cytometry was developed. Plasma concentrations of INH and AcINH were obtained by HPLC in TB patients and the Metabolic Ratio (MR) was calculated. The phenotypes obtained in the healthy volunteers were as follows; 18.87 % of subjects had the rapid acetylator phenotype, 45.45 % had the intermediate phenotype and 39.66 % exhibited the slow acetylator phenotype. In the TB patient group, 35 % of patients had the rapid acetylator phenotype, 32.5 % were intermediate and 32.5 % showed the slow acetylator phenotype. A higher expression level of NAT2 in innate immune cells from TB patients compared to those from healthy volunteers was detected (P < 0.013). In TB patients the MR showed a bimodal distribution with an antimode of 0.7, which was used as a threshold value for acetylator classification. A high correspondence between the rapid and slow acetylator phenotype with MR was demonstrated. In conclusion, the 282C>T, 341T>C, 481C>T, 590G>A, 803A>G, 857G>A SNPs of NAT2 gene provides accurate for prediction of the acetylator phenotype in Mexican mestizo population. A statistical difference was found in frequency of rapid metabolizer phenotype, which was higher in TB patients. In addition, the expression of NAT2 protein in immune cells can lead to further studies related to its functional role in the innate immune response against M. tuberculosis and other xenobiotics

  2. Detection of Mycobacterium tuberculosis by EasyNAT diagnostic kit in sputum samples from Tanzania.

    PubMed

    Mhimbira, Francis A; Bholla, Maira; Sasamalo, Mohamed; Mukurasi, William; Hella, Jerry J; Jugheli, Levan; Reither, Klaus

    2015-04-01

    The EasyNAT assay was evaluated for the detection of tuberculosis in sputum smears from presumptive pulmonary tuberculosis (TB) patients in an African high-TB and high-HIV setting. The sensitivity of the EasyNAT assay was 66.7%, and the specificity and positive predictive value were 100% for the culture-positive patients. The sensitivity was only 10% in the smear-negative and culture-positive patients. PMID:25609720

  3. NAT2 gene polymorphisms in three indigenous groups in the Colombian Caribbean Coast region

    PubMed Central

    Arias, Isis; Lecompte, Nelly; Visbal, Lila; Curiel, Iliana; Hernández, Enio; Garavito, Pilar

    2014-01-01

    Objective: To study the NAT2 gene polymorphisms 481T, 590A and 857A in the Chimila, Wiwa and Wayuu indigenous groups of the Colombian Caribbean to determine the frequencies of the alleles NAT2*4, NAT2*5, NAT2*6, and NAT2*7 and to determine the types of acetylators present in these populations. Methods: A total of 202 subjects were studied: 47 Chimila, 55 Wiwa, and 100 Wayuu. The polymorphisms were identified using a real-time PCR method for allelic discrimination designed using Taqman of Applied Biosystems. Results: The following alleles were found at the highest frequency in the following groups: the NAT2*4 allele (wild type) in the Wayuu group (55.3%), the NAT2*5 allele in the Wiwa group (34.5%), and the NAT2*7 allele in the Chimila group (24.2%). A higher frequency of the rapid acetylator status was found in the Wayuu group (31.3%) and Chimila group (29.5%) compared with the Wiwa group (12.7%). The intermediate acetylator status distribution was very similar in all three groups, and the frequency of the slow acetylator status was higher in the Wiwa group (32.7%) compared with the Chimila and Wayuu groups (20.5% and 21.2%, respectively). Conclusion: The results demonstrated the allelic distribution and pharmacogenetic differences of the three groups studied and revealed the most frequent acetylator status and phenotype. Because of the high prevalence of slow acetylators, a greater incidence of tuberculosis (TB) drug-induced hepatotoxicity is predicted in these populations, with a higher frequency in the Wiwa group. PMID:25767302

  4. SP-100 GES/NAT radiation shielding systems design and development testing

    NASA Astrophysics Data System (ADS)

    Disney, Richard K.; Kulikowski, Henry D.; McGinnis, Cynthia A.; Reese, James C.; Thomas, Kevin; Wiltshire, Frank

    The design approach and development testing to support the design, fabrication, and assembly of three shield components for use within the vacuum vessel of the SP-100 Ground Engineering System Nuclear Assembly Test (GES/NAT) are described. The GES/NAT shields must be designed to operate in a high vacuum which simulates space operations. Shielding, thermal, and structural performance have been demonstrated by a combination of detailed analyses. Key tests to obtain critical design data and design feature performance are reviewed.

  5. Clarifying haplotype ambiguity of NAT2 in multi-national cohorts.

    PubMed

    Selinski, Silvia; Blaszkewicz, Meinolf; Agundez, Jose A G; Martinez, Carmen; Garcia-Martin, Elena; Hengstler, Jan G; Golka, Klaus

    2013-01-01

    N-Acetyltransferase 2 (NAT2) is the key enzyme in aromatic amine metabolism. NAT2 genotyping requires a subsequent determination of the haplotype pairs (formerly: alleles) to derive the acetylation status. The chromosomal phase of the single nucleotide polymorphisms (SNPs) is unclear for about 2/3 of the genotypes. We investigated NAT2 genotypes of 1,234 bladder cancer cases and 2,207 controls from Germany, Hungary, Pakistan and Venezuela plus 696 further German cancer cases. We reconstructed NAT2 haplotypes using PHASE v2.1.1. We analysed if the variability of the NAT2 haplotypes affected the haplotype reconstruction. Furthermore, we compared population haplotype frequencies in three Caucasian control cohorts (German, Hungarian, Spanish), in Pakistanis and Venezuelans and the impact on bladder cancer. We conclude that a common haplotype reconstruction is feasible, enhances precision and reliability. Hungarian controls showed the largest intra-ethnic variability whereas the Pakistanis showed a haplotype distribution typical for Caucasians. The main differences could be observed for the slow haplotypes *5B, *6A and *7B. The association of slow NAT2 genotypes with bladder cancer risk was most prominent in the Venezuelan study group. PMID:23277078

  6. Floating mucoadhesive alginate beads of amoxicillin trihydrate: A facile approach for H. pylori eradication.

    PubMed

    Dey, Sanjoy Kumar; De, Pintu Kumar; De, Arnab; Ojha, Souvik; De, Ronita; Mukhopadhyay, Asish Kumar; Samanta, Amalesh

    2016-08-01

    This study investigates the design of sunflower oil entrapped floating and mucoadhesive beads of amoxicillin trihydrate using sodium alginate and hydroxypropyl methylcellulose as matrix polymers and chitosan as coating polymer to localize the antibiotic at the stomach site against Helicobacter pylori. Beads prepared by ionotropic gellation technique were evaluated for different physicochemical, in-vitro and in-vivo properties. Beads of all batches were floated for >24h with a maximum lag time of 46.3±3.2s. Scanning electron microscopy revealed that the beads were spherical in shape with few oil filled channels distributed throughout the surfaces and small pocket structures inside the matrix confirming oil entrapment. Prepared beads showed good mucoadhesiveness of 75.7±3.0% to 85.0±5.5%. The drug release profile was best fitted to Higuchi model with non fickian driven mechanism. The optimized batch showed 100% Helicobacter pylori growth inhibition in 15h in in-vitro culture. Furthermore, X-ray study in rabbit stomach confirmed the gastric retention of optimized formulation. The results exhibited that formulated beads may be preferred to localize the antibiotic in the gastric region to allow more availability of antibiotic at gastric mucus layer acting on Helicobacter pylori, thereby improving the therapeutic efficacy. PMID:27177460

  7. Formulation and Evaluation of Cefixime Trihydrate Matrix Tablets Using HPMC, Sodium CMC, Ethyl Cellulose.

    PubMed

    Sirisolla, Janakidevi; Ramanamurthy, K V

    2015-01-01

    The objective of the present work is to design sustained release matrix tablets of cefixime trihydrate by incorporating drug in a matrix made up of release retardant polymers, which prolong drug release leading to minimization of the peak and valley effect in the plasma and provide patient convenience. The effect of combination of polymers on parameters like release pattern, release mechanism of the drug were studied. Total nine formulations each containing 200 mg of drug were prepared by direct compression method. The formulations F-1, F-2, F-3 were prepared with a 1:1 drug to polymer ratio using hydroxypropyl methylcellulose, carboxymethyl cellulose sodium and ethyl cellulose. F-4 was prepared with a 1:1 ratio of hydroxypropyl methylcellulose, carboxymethyl cellulose sodium, F-5 as prepared with a 1:1 ratio of hydroxypropyl methylcellulose and ethyl cellulose, F-6 was prepared with a 1:1 ratio of carboxymethyl cellulose sodium and ethyl cellulose, F-7, F-8, F-9 were prepared by using polymers hydroxypropyl methylcellulose, carboxymethyl cellulose sodium and ethyl cellulose in the ratios of 0.5:0.5:1, 0.5:1:0.5, and 1:0.5:0.5. Designed matrix tablets were evaluated for various pre-compression and post-compression parameters. Formulation F-5 showed 102.15 % release at the end of 12 h and it is selected as the best formulation. All Formulations followed zero order with non-Fickian diffusion method. PMID:26180278

  8. Formulation and Evaluation of Cefixime Trihydrate Matrix Tablets Using HPMC, Sodium CMC, Ethyl Cellulose

    PubMed Central

    Sirisolla, Janakidevi; Ramanamurthy, K. V.

    2015-01-01

    The objective of the present work is to design sustained release matrix tablets of cefixime trihydrate by incorporating drug in a matrix made up of release retardant polymers, which prolong drug release leading to minimization of the peak and valley effect in the plasma and provide patient convenience. The effect of combination of polymers on parameters like release pattern, release mechanism of the drug were studied. Total nine formulations each containing 200 mg of drug were prepared by direct compression method. The formulations F-1, F-2, F-3 were prepared with a 1:1 drug to polymer ratio using hydroxypropyl methylcellulose, carboxymethyl cellulose sodium and ethyl cellulose. F-4 was prepared with a 1:1 ratio of hydroxypropyl methylcellulose, carboxymethyl cellulose sodium, F-5 as prepared with a 1:1 ratio of hydroxypropyl methylcellulose and ethyl cellulose, F-6 was prepared with a 1:1 ratio of carboxymethyl cellulose sodium and ethyl cellulose, F-7, F-8, F-9 were prepared by using polymers hydroxypropyl methylcellulose, carboxymethyl cellulose sodium and ethyl cellulose in the ratios of 0.5:0.5:1, 0.5:1:0.5, and 1:0.5:0.5. Designed matrix tablets were evaluated for various pre-compression and post-compression parameters. Formulation F-5 showed 102.15 % release at the end of 12 h and it is selected as the best formulation. All Formulations followed zero order with non-Fickian diffusion method. PMID:26180278

  9. Effect of Silver Nanoparticles on the Thermal Properties of Sodium Acetate Trihydrate

    NASA Astrophysics Data System (ADS)

    Garay-Ramírez, B.; Cruz-Orea, A.; San Martín-Martínez, E.

    2015-06-01

    Sodium acetate trihydrate (SAT) is used as a phase change material (PCM) because of its high latent heat of fusion. Mixtures were prepared with SAT, a blend of the polymer sodium carboxymethil cellulose (CMC) and silica gel, silver nanoparticles (AgNPs), and anhydrous sodium sulfate to form a composite-PCM (c-PCM) based on SAT; the relative proportions of CMC/silica gel in the blend and AgNP content were varied according to a central composite experimental design. The thermal properties were determined for raw SAT, CMC, , and c-PCM samples. The thermal effusivity of samples was evaluated by the inverse photopyroelectric technique. The thermal diffusivity was obtained for samples by the open photoacoustic cell technique. The thermal conductivity was calculated from the obtained and values. To assess the thermal performance of the c-PCM compared to raw SAT, samples were studied through differential scanning calorimetry which served to determine the latent heat recovery ( LHR). Properties , and LHR were analyzed by response surface methodology and compared. The SAT-based c-PCM was found to be more thermally conductive than raw SAT. The best LHR with good thermal diffusivity and thermal conductivity was identified in the region of the central composite experimental design with medium-low AgNPs and higher proportions of CMC in the polymer blend.

  10. Arylamine N-Acetyltransferase 2 (NAT2) Genetic Diversity and Traditional Subsistence: A Worldwide Population Survey

    PubMed Central

    Sabbagh, Audrey; Darlu, Pierre; Crouau-Roy, Brigitte; Poloni, Estella S.

    2011-01-01

    Arylamine N-acetyltransferase 2 (NAT2) is involved in human physiological responses to a variety of xenobiotic compounds, including common therapeutic drugs and exogenous chemicals present in the diet and the environment. Many questions remain about the evolutionary mechanisms that have led to the high prevalence of slow acetylators in the human species. Evidence from recent surveys of NAT2 gene variation suggests that NAT2 slow-causing variants might have become targets of positive selection as a consequence of the shift in modes of subsistence and lifestyle in human populations in the last 10,000 years. We aimed to test more extensively the hypothesis that slow acetylation prevalence in humans is related to the subsistence strategy adopted by the past populations. To this end, published frequency data on the most relevant genetic variants of NAT2 were collected from 128 population samples (14,679 individuals) representing different subsistence modes and dietary habits, allowing a thorough analysis at both a worldwide and continent scale. A significantly higher prevalence of the slow acetylation phenotype was observed in populations practicing farming (45.4%) and herding (48.2%) as compared to populations mostly relying on hunting and gathering (22.4%) (P = 0.0007). This was closely mirrored by the frequency of the slow 590A variant that was found to occur at a three-fold higher frequency in food producers (25%) as compared to hunter-gatherers (8%). These findings are consistent with the hypothesis that the Neolithic transition to subsistence economies based on agricultural and pastoral resources modified the selective regime affecting the NAT2 acetylation pathway. Furthermore, the vast amount of data collected enabled us to provide a comprehensive and up-to-date description of NAT2 worldwide genetic diversity, thus building up a useful resource of frequency data for further studies interested in epidemiological or anthropological research questions involving

  11. Time-resolved infrared reflectance studies of the dehydration-induced transformation of uranyl nitrate hexahydrate to the trihydrate form

    DOE PAGESBeta

    Johnson, Timothy J.; Sweet, Lucas E.; Meier, David E.; Edward J. Mausolf; Kim, Eunja; Weck, Philippe F.; Buck, Edgar C.; Bruce K. McNamara

    2015-09-08

    Uranyl nitrate is a key species in the nuclear fuel cycle. However, this species is known to exist in different states of hydration, including the hexahydrate ([UO2(NO3)2(H2O)6] often called UNH), the trihydrate [UO2(NO3)2(H2O)3 or UNT], and in very dry environments the dihydrate form [UO2(NO3)2(H2O)2]. Their relative stabilities depend on both water vapor pressure and temperature. In the 1950s and 1960s, the different phases were studied by infrared transmission spectroscopy but were limited both by instrumental resolution and by the ability to prepare the samples for transmission. We have revisited this problem using time-resolved reflectance spectroscopy, which requires no sample preparationmore » and allows dynamic analysis while the sample is exposed to a flow of N2 gas. Samples of known hydration state were prepared and confirmed via X-ray diffraction patterns of known species. In reflectance mode the hexahydrate UO2(NO3)2(H2O)6 has a distinct uranyl asymmetric stretch band at 949.0 cm–1 that shifts to shorter wavelengths and broadens as the sample desiccates and recrystallizes to the trihydrate, first as a shoulder growing in on the blue edge but ultimately results in a doublet band with reflectance peaks at 966 and 957 cm–1. The data are consistent with transformation from UNH to UNT as UNT has two inequivalent UO22+ sites. The dehydration of UO2(NO3)2(H2O)6 to UO2(NO3)2(H2O)3 is both a structural and morphological change that has the lustrous lime green UO2(NO3)2(H2O)6 crystals changing to the matte greenish yellow of the trihydrate solid. As a result, the phase transformation and crystal structures were confirmed by density functional theory calculations and optical microscopy methods, both of which showed a transformation with two distinct sites for the uranyl cation in the trihydrate, with only one in the hexahydrate.« less

  12. Time-Resolved Infrared Reflectance Studies of the Dehydration-Induced Transformation of Uranyl Nitrate Hexahydrate to the Trihydrate Form

    SciTech Connect

    Johnson, Timothy J.; Sweet, Lucas E.; Meier, David E.; Mausolf, Edward J.; Kim, Eunja; Weck, Philippe F.; Buck, Edgar C.; McNamara, Bruce K.

    2015-10-01

    Uranyl nitrate is a key species in the nuclear fuel cycle. However, this species is known to exist in different states of hydration, including the hexahydrate ([UO2(NO3)2(H2O)6] often called UNH), the trihydrate [UO2(NO3)2(H2O)3 or UNT], and in very dry environments the dihydrate form [UO2(NO3)2(H2O)2]. Their relative stabilities depend on both water vapor pressure and temperature. In the 1950s and 1960s the different phases were studied by infrared transmission spectroscopy, but were limited both by instrumental resolution and by the ability to prepare the samples for transmission. We have revisited this problem using time-resolved reflectance spectroscopy, which requires no sample preparation and allows dynamic analysis while the sample is exposed to a flow of N2 gas. Samples of known hydration state were prepared and confirmed via X-ray diffraction patterns of known species. In reflectance mode the hexahydrate UO2(NO3)2(H2O)6 has a distinct uranyl asymmetric stretch band at 949.0 cm-1 that shifts to shorter wavelengths and broadens as the sample desiccates and recrystallizes to the trihydrate, first as a shoulder growing in on the blue edge but ultimately results in a doublet band with reflectance peaks at 966 and 957 cm-1. The data are consistent with transformation from UNH to UNT as UNT has two inequivalent UO22+ sites. The dehydration of UO2(NO3)2(H2O)6 to UO2(NO3)2(H2O)3 is both a structural and morphological change that has the lustrous lime green UO2(NO3)2(H2O)6 crystals changing to the matte greenish yellow of the trihydrate solid. The phase transformation and crystal structures were confirmed by density functional theory calculations and optical microscopy methods, both of which showed a transformation with two distinct sites for the uranyl cation in the trihydrate, with but one in the hexahydrate.

  13. Purification, crystallization and preliminary X-ray characterization of Bacillus cereus arylamine N-acetyltransferase 3 [(BACCR)NAT3].

    PubMed

    Kubiak, Xavier; Pluvinage, Benjamin; Li de la Sierra-Gallay, Inès; Weber, Patrick; Haouz, Ahmed; Dupret, Jean-Marie; Rodrigues-Lima, Fernando

    2012-02-01

    Arylamine N-acetyltransferases (NATs) are xenobiotic metabolizing enzymes (XMEs) that catalyze the acetylation of arylamines. All functional NATs described to date possess a strictly conserved Cys-His-Asp catalytic triad. Here, the purification, crystallization and preliminary X-ray characterization of Bacillus cereus arylamine N-acetyltransferase 3 [(BACCR)NAT3], a putative NAT isoenzyme that possesses a unique catalytic triad containing a glutamate residue, is reported. The crystal diffracted to 2.42 Å resolution and belonged to the monoclinic space group C121, with unit-cell parameters a = 90.44, b = 44.52, c = 132.98 Å, β = 103.8°. PMID:22297998

  14. Pharmacokinetics of amoxicillin trihydrate in male Asian elephants (Elephas maximus) following intramuscular administration.

    PubMed

    Sinphithakkul, P; Klangkaew, N; Sanyathitiseree, P; Giorgi, M; Kumagai, S; Poapolathep, A; Poapolathep, S

    2016-06-01

    The purpose of this study was to investigate the pharmacokinetic characteristics of amoxicillin (AMX) trihydrate in male Asian elephants, Elephas maximus, following intramuscular administration at two dosages of 5.5 and 11 mg/kg body weight (b.w.). Blood samples were collected from 0.5 up to 72 h. The concentration of AMX in elephant plasma was measured using liquid chromatography electrospray ionization mass spectrometry. AMX was measurable up to 24 h after administration at two dosages. Peak plasma concentration (Cmax ) was 1.20 ± 0.39 μg/mL after i.m. administration at a dosage of 5.5 mg/kg b.w., whereas it was 3.40 ± 0.63 μg/mL at a dosage of 11 mg/kg b.w. A noncompartment model was developed to describe the disposition of AMX in Asian elephants. Based on the preliminary findings found in this research, the dosage of 5.5 and 11 mg/kg b.w. produced drug plasma concentrations higher than 0.25 mg/mL for 24 h after i.m. administration. Thereafter, i.m. administration with AMX at a dosage of 5.5 mg/kg b.w. appeared a more suitable dose than 11 mg/kg b.w. However, more studies are needed to determine AMX clinical effectiveness in elephants. PMID:26411748

  15. NATb/NAT1*4 promotes greater arylamine N-acetyltransferase 1 mediated DNA adducts and mutations than NATa/NAT1*4 following exposure to 4-aminobiphenyl

    PubMed Central

    Millner, Lori M.; Doll, Mark A.; Cai, Jian; States, J. Christopher; Hein, David W.

    2011-01-01

    N -acetyltransferase 1 (NAT1) is a phase II metabolic enzyme responsible for the biotransformation of aromatic and heterocyclic amine carcinogens such as 4-aminobiphenyl (ABP). NAT1 catalyzes N-acetylation of arylamines as well as the O-acetylation of N-hydroxylated arylamines. O-acetylation leads to the formation of electrophilic intermediates that result in DNA adducts and mutations. NAT1 is transcribed from a major promoter, NATb, and an alternative promoter, NATa, resulting in mRNAs with distinct 5′-untranslated regions (UTR). NATa mRNA is expressed primarily in the kidney, liver, trachea and lung while NATb mRNA has been detected in all tissues studied. To determine if differences in 5′-UTR have functional effect upon NAT1 activity and DNA adducts or mutations following exposure to ABP, pcDNA5/FRT plasmid constructs were prepared for transfection of full length human mRNAs including the 5′-UTR derived from NATa or NATb, the open reading frame, and 888 nucleotides of the 3′-UTR. Following stable transfection of NATb/NAT1*4 or NATa/NAT1*4 into nucleotide excision repair (NER) deficient Chinese hamster ovary cells, N-acetyltransferase activity (in vitro and in situ), mRNA, and protein expression were higher in NATb/NAT1*4 than NATa/NAT1*4 transfected cells (p<0.05). Consistent with NAT1 expression and activity, ABP-induced DNA adducts and hypoxanthine phosphoribosyl transferase mutants were significantly higher (p<0.05) in NATb/NAT1*4 than in NATa/NAT1*4 transfected cells following exposure to ABP. These differences observed between NATa and NATb suggest that the 5′-UTRs are differentially regulated. PMID:21837760

  16. Pooled analysis of NAT2 genotypes as risk factors for asbestos-related malignant mesothelioma.

    PubMed

    Betti, Marta; Neri, Monica; Ferrante, Daniela; Landi, Stefano; Biava, Alessandra; Gemignani, Federica; Bertolotti, Marinella; Mirabelli, Dario; Padoan, Marina; Ugolini, Donatella; Botta, Mario; Bonassi, Stefano; Magnani, Corrado; Dianzani, Irma

    2009-05-01

    Malignant mesothelioma (MM) is a rare and aggressive tumor of the pleura. The most important causal factor for the development of MM is occupational exposure to asbestos. Different lines of evidence suggest a role of genetic background in MM development, as for other cancers. Two published studies observed an association between MM and N-acetyl-transferase 2 (NAT2) polymorphisms. First, a Finnish study observed that the NAT2 slow acetylator phenotype was associated with an increased risk of MM. Conversely, MM risk was higher in Italian subjects carrying the NAT2 fast acetylator genotypes. The conflicting results obtained in Finland and Italy could be ascribed to random chance, considering the small panel of patients and controls in the two studies, but also ethnic or other differences may have been important. To ascertain the role of NAT2 genotype, we performed a study on 252 MM patients and 262 controls recruited in two Northern Italy areas that were characterized by high asbestos exposure, due to intense industrial activities (an asbestos cement factory in Casale Monferrato, mainly shipyards and refineries in Liguria). Unconditional multivariate logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs). NAT2 fast acetylator genotypes showed an increased OR, although not statistically significant, both in asbestos-exposed subjects (OR=1.47; 95% CI=0.96-2.26) and in the entire population (OR=1.38; 95% CI=0.93-2.04). These results suggest that NAT2 polymorphisms do not exert a strong effect on individual susceptibility to MM. PMID:18838334

  17. SP-100 GES/NAT radiation shielding systems design and development testing

    SciTech Connect

    Disney, R.K.; Kulikowski, H.D.; McGinnis, C.A.; Reese, J.C.; Thomas, K. ); Wiltshire, F. )

    1991-01-10

    Advanced Energy Systems (AES) of Westinghouse Electric Corporation is under subcontract to the General Electric Company to supply nuclear radiation shielding components for the SP-100 Ground Engineering System (GES) Nuclear Assembly Test to be conducted at Westinghouse Hanford Company at Richland, Washington. The radiation shielding components are integral to the Nuclear Assembly Test (NAT) assembly and include prototypic and non-prototypic radiation shielding components which provide prototypic test conditions for the SP-100 reactor subsystem and reactor control subsystem components during the GES/NAT operations. W-AES is designing three radiation shield components for the NAT assembly; a prototypic Generic Flight System (GFS) shield, the Lower Internal Facility Shield (LIFS), and the Upper Internal Facility Shield (UIFS). This paper describes the design approach and development testing to support the design, fabrication, and assembly of these three shield components for use within the vacuum vessel of the GES/NAT. The GES/NAT shields must be designed to operate in a high vacuum which simulates space operations. The GFS shield and LIFS must provide prototypic radiation/thermal environments and mechanical interfaces for reactor system components. The NAT shields, in combination with the test facility shielding, must provide adequate radiation attenuation for overall test operations. Special design considerations account for the ground test facility effects on the prototypic GFS shield. Validation of the GFS shield design and performance will be based on detailed Monte Carlo analyses and developmental testing of design features. Full scale prototype testing of the shield subsystems is not planned.

  18. NAT2 polymorphisms combining with smoking associated with breast cancer susceptibility: a meta-analysis.

    PubMed

    Zhang, Jian; Qiu, Li-Xin; Wang, Zhong-Hua; Wang, Jia-Lei; He, Shuang-Shuang; Hu, Xi-Chun

    2010-10-01

    To derive a more precise estimation of the relationship between the slow or rapid acetylation resulting from N-acetyltransferase 2 (NAT2) polymorphisms and breast cancer risk, a meta-analysis was performed. PubMed, Medline, Embase, and Web of Science were searched. Crude odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess strength of association. The pooled ORs were performed for slow versus rapid acetylation genotypes. A total of 26 studies including 9,215 cases and 10,443 controls were included in the meta-analysis. Overall, no significantly elevated breast cancer risk was associated with NAT2 slow genotypes when all studies were pooled into the meta-analysis (OR = 1.026, 95% CI = 0.968-1.087). In the subgroup analysis by ethnicity, increased risks were not found for either Caucasians (OR = 1.001, 95% CI = 0.938-1.068) or Asians (OR = 1.155, 95% CI = 0.886-1.506). When stratified by study design, statistically significantly elevated risk associated with NAT2 slow genotypes was only found among hospital-based studies (OR = 1.178, 95% CI = 1.037-1.339). In the subgroup analysis by menopausal status, no statistically significantly increased risk was found in either premenopausal (OR = 1.053, 95% CI = 0.886-1.252) or postmenopausal women (OR = 0.965, 95% CI = 0.844-1.104). When stratified by cumulative smoking exposure, in the subgroup of smokers with high pack-years, NAT2 slow genotypes were significantly associated with increased breast cancer risk (OR = 1.400, 95% CI = 1.099-1.784). In conclusion, this meta-analysis suggested that there is overall lack of association between NAT2 genotypes and breast cancer risk, however, NAT2 polymorphisms when combining with heavy smoking history may contribute to breast cancer susceptibility. PMID:20180012

  19. Red meat intake, NAT2, and risk of colorectal cancer: A pooled analysis of 11 studies

    PubMed Central

    Ananthakrishnan, Ashwin N.; Du, Mengmeng; Berndt, Sonja I.; Brenner, Hermann; Caan, Bette J.; Casey, Graham; Chang-Claude, Jenny; Duggan, David; Fuchs, Charles S.; Gallinger, Steven; Giovannucci, Edward L.; Harrison, Tabitha A.; Hayes, Richard B.; Hoffmeister, Michael; Hopper, John L.; Hou, Lifang; Hsu, Li; Jenkins, Mark A.; Kraft, Peter; Ma, Jing; Nan, Hongmei; Newcomb, Polly A.; Ogino, Shuji; Potter, John D.; Seminara, Daniela; Slattery, Martha L.; Thornquist, Mark; White, Emily; Wu, Kana; Peters, Ulrike; Chan, Andrew T.

    2014-01-01

    Background Red meat intake has been associated with risk of colorectal cancer (CRC), potentially mediated through heterocyclic amines. The metabolic efficiency of N-acetyltransferase 2 (NAT2) required for the metabolic activation of such amines is influenced by genetic variation. The interaction between red meat intake, NAT2 genotype, and CRC has been inconsistently reported. Methods We used pooled individual-level data from the Colon Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO). Red meat intake was collected by each study. We inferred NAT2 phenotype based on polymorphism at rs1495741, highly predictive of enzyme activity. Interaction was assessed using multiplicative interaction terms in multivariate-adjusted models. Results From 11 studies, 8,290 CRC cases and 9,115 controls were included. The highest quartile of red meat intake was associated with increased risk of CRC compared to the lowest quartile (OR 1.41, 95%CI 1.29 – 1.55). However, a significant association was observed only for studies with retrospective diet data, not for studies with diet prospectively assessed before cancer diagnosis. Combining all studies, high red meat intake was similarly associated with CRC in those with a rapid/intermediate NAT2 genotype (OR 1.38, 95%CI 1.20 – 1.59) as with a slow genotype (OR 1.43, 95%CI 1.28 – 1.61) (p- interaction=0.9). Conclusion We found that high red meat intake was associated with increased risk of CRC only from retrospective case-control studies and not modified by NAT2 enzyme activity. Impact Our results suggest no interaction between NAT2 genotype and red-meat intake in mediating risk of CRC. PMID:25342387

  20. SP-100 GES/NAT radiation shielding systems design and development testing

    NASA Astrophysics Data System (ADS)

    Disney, Richard K.; Kulikowski, Henry D.; McGinnis, Cynthia A.; Reese, James C.; Thomas, Kevin; Wiltshire, Frank

    1991-01-01

    Advanced Energy Systems (AES) of Westinghouse Electric Corporation is under subcontract to the General Electric Company to supply nuclear radiation shielding components for the SP-100 Ground Engineering System (GES) Nuclear Assembly Test to be conducted at Westinghouse Hanford Company at Richland, Washington. The radiation shielding components are integral to the Nuclear Assembly Test (NAT) assembly and include prototypic and non-prototypic radiation shielding components which provide prototypic test conditions for the SP-100 reactor subsystem and reactor control subsystem components during the GES/NAT operations. W-AES is designing three radiation shield components for the NAT assembly; a prototypic Generic Flight System (GFS) shield, the Lower Internal Facility Shield (LIFS), and the Upper Internal Facility Shield (UIFS). This paper describes the design approach and development testing to support the design, fabrication, and assembly of these three shield components for use within the vacuum vessel of the GES/NAT. The GES/NAT shields must be designed to operate in a high vacuum which simulates space operations. The GFS shield and LIFS must provide prototypic radiation/thermal environments and mechanical interfaces for reactor system components. The NAT shields, in combination with the test facility shielding, must provide adequate radiation attenuation for overall test operations. Special design considerations account for the ground test facility effects on the prototypic GFS shield. Validation of the GFS shield design and performance will be based on detailed Monte Carlo analyses and developmental testing of design features. Full scale prototype testing of the shield subsystems is not planned.

  1. Induction of neuronal axon outgrowth by Shati/Nat8l by energy metabolism in mice cultured neurons.

    PubMed

    Sumi, Kazuyuki; Uno, Kyosuke; Matsumura, Shohei; Miyamoto, Yoshiaki; Furukawa-Hibi, Yoko; Muramatsu, Shin-Ichi; Nabeshima, Toshitaka; Nitta, Atsumi

    2015-09-01

    A novel N-acetyltransferase, Shati/Nat8l, was identified in the nucleus accumbens of mice repeatedly treated with methamphetamine (METH). Shati/Nat8l has been reported to inhibit the pharmacological action induced by METH. Shati/Nat8l produces N-acetylaspartate from aspartate and acetyl-CoA. Previously, we reported that overexpression of Shati/Nat8l in nucleus accumbens attenuates the response to METH by N-acetylaspartylglutamate (which is derived from N-acetylaspartate)-mGluR3 signaling in the mice brain. In the present study, to clarify the type of cells that produce Shati/Nat8l, we carried out in-situ hybridization for the detection of Shati/Nat8l mRNA along with immunohistochemical studies using serial sections of mice brain. Shati/Nat8l mRNA was detected in neuronal cells, but not in astrocytes or microglia cells. Next, we investigated the function of Shati/Nat8l in the neuronal cells in mice brain; then, we used an adeno-associated virus vector containing Shati/Nat8l for transfection and overexpression of Shati/Nat8l protein into the primary cultured neurons to investigate the contribution toward the neuronal activity of Shati/Nat8l. Overexpression of Shati/Nat8l in the mice primary cultured neurons induced axonal growth, but not dendrite elongation at day 1.5 (DIV). This finding indicated that Shati/Nat8l contributes toward neuronal development. LY341495, a selective group II mGluRs antagonist, did not abolish this axonal growth, and N-acetylaspartylglutamate itself did not abolish axon outgrowth in the same cultured system. The cultured neurons overexpressing Shati/Nat8l contained high ATP, suggesting that axon outgrowth is dependent on energy metabolism. This study shows that Shati/Nat8l in the neuron may induce axon outgrowth by ATP synthesis and not through mGluR3 signaling. PMID:26164607

  2. Suitability of the HAM-Nat test and TMS module "basic medical-scientific understanding" for medical school selection

    PubMed Central

    Hissbach, Johanna; Feddersen, Lena; Sehner, Susanne; Hampe, Wolfgang

    2012-01-01

    Aims: Tests with natural-scientific content are predictive of the success in the first semesters of medical studies. Some universities in the German speaking countries use the ‘Test for medical studies’ (TMS) for student selection. One of its test modules, namely “medical and scientific comprehension”, measures the ability for deductive reasoning. In contrast, the Hamburg Assessment Test for Medicine, Natural Sciences (HAM-Nat) evaluates knowledge in natural sciences. In this study the predictive power of the HAM-Nat test will be compared to that of the NatDenk test, which is similar to the TMS module “medical and scientific comprehension” in content and structure. Methods: 162 medical school beginners volunteered to complete either the HAM-Nat (N=77) or the NatDenk test (N=85) in 2007. Until spring 2011, 84.2% of these successfully completed the first part of the medical state examination in Hamburg. Via different logistic regression models we tested the predictive power of high school grade point average (GPA or “Abiturnote”) and the test results (HAM-Nat and NatDenk) with regard to the study success criterion “first part of the medical state examination passed successfully up to the end of the 7th semester” (Success7Sem). The Odds Ratios (OR) for study success are reported. Results: For both test groups a significant correlation existed between test results and study success (HAM-Nat: OR=2.07; NatDenk: OR=2.58). If both admission criteria are estimated in one model, the main effects (GPA: OR=2.45; test: OR=2.32) and their interaction effect (OR=1.80) are significant in the HAM-Nat test group, whereas in the NatDenk test group only the test result (OR=2.21) significantly contributes to the variance explained. Conclusions: On their own both HAM-Nat and NatDenk have predictive power for study success, but only the HAM-Nat explains additional variance if combined with GPA. The selection according to HAM-Nat and GPA has under the current

  3. Proper regulation of a sperm-specific cis-nat-siRNA is essential for double fertilization in Arabidopsis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    /Cis/-nat-siRNAs are a recently characterized class of small regulatory RNAs that are widespread in eukaryotes. Despite their abundance the importance of their regulatory activity is largely unknown. The only functional role for eukaryotic /cis/-nat-siRNAs that has been described to date is in envir...

  4. Excitation functions of alpha particle induced reactions on natTi up to 40 MeV

    NASA Astrophysics Data System (ADS)

    Uddin, M. S.; Scholten, B.

    2016-08-01

    Excitation functions of the reactions natTi(α,x)48Cr, natTi(α,x)48V and natTi(α,x)46,48Sc were determined by the stacked-foil activation technique up to 40 MeV. The radioactivities produced in the natTi target were measured by γ-ray spectrometry using HPGe detector. The reaction natTi(α,x)51Cr was used to determine the beam parameters. New experimental values for the above reactions have been obtained. An intercomparison of our data with the available literature values has been done. The cross section results obtained in this work could be useful in defining new monitor reactions, radiation safety and isotope production.

  5. The Pharmacogenetics of NAT2 Enzyme Maturation in Perinatally HIV Exposed Infants Receiving Isoniazid

    PubMed Central

    Zhu, Rui; Kiser, Jennifer J.; Seifart, Heiner I.; Werely, Cedric J.; Mitchell, Charles D.; D’Argenio, David Z.; Fletcher, Courtney V.

    2011-01-01

    The roles of the NAT2 genotype and enzyme maturation on isoniazid pharmacokinetics were investigated in South African infants with perinatal HIV exposure enrolled in a randomized, double-blind, controlled trial of isoniazid for prevention of tuberculosis disease and latent infection. Plasma concentration-time measurements of isoniazid from 151 infants (starting at 3-4 months of age) receiving isoniazid 10 to 20 mg/kg/d orally during the course of the 24-month study were incorporated in a population analysis along with NAT2 genotype, body weight, age, and sex. The results showed a different NAT2 enzyme maturation profile for each of the 3 acetylation groups, with the 70-kg body weight–normalized typical apparent clearance for the fast and intermediate acetylators increasing from 14.25 L/h and 10.88 L/h at 3 months of age to 22.84 L/h and 15.58 L/h at 24 months of age, respectively, with no significant change in the apparent clearance of the slow group during this period. A hypothesis is proposed to explain the genotype-dependent enzyme maturation processes for the NAT2 enzyme. PMID:21558457

  6. AmeriFlux US-SP1 Slashpine-Austin Cary- 65yrs nat regen

    SciTech Connect

    Martin, Tim

    2016-01-01

    This is the AmeriFlux version of the carbon flux data for the site US-SP1 Slashpine-Austin Cary- 65yrs nat regen. Site Description - The ACMF site is a 67 hectare naturally regenerated Pinus palustris and Pinus elliottii mixed stand.

  7. National Carbon Sequestration Database and Geographic Information System (NatCarb)

    SciTech Connect

    Kenneth Nelson; Timothy Carr

    2009-03-31

    This annual and final report describes the results of the multi-year project entitled 'NATional CARBon Sequestration Database and Geographic Information System (NatCarb)' (http://www.natcarb.org). The original project assembled a consortium of five states (Indiana, Illinois, Kansas, Kentucky and Ohio) in the midcontinent of the United States (MIDCARB) to construct an online distributed Relational Database Management System (RDBMS) and Geographic Information System (GIS) covering aspects of carbon dioxide (CO{sub 2}) geologic sequestration. The NatCarb system built on the technology developed in the initial MIDCARB effort. The NatCarb project linked the GIS information of the Regional Carbon Sequestration Partnerships (RCSPs) into a coordinated regional database system consisting of datasets useful to industry, regulators and the public. The project includes access to national databases and GIS layers maintained by the NatCarb group (e.g., brine geochemistry) and publicly accessible servers (e.g., USGS, and Geography Network) into a single system where data are maintained and enhanced at the local level, but are accessed and assembled through a single Web portal to facilitate query, assembly, analysis and display. This project improves the flow of data across servers and increases the amount and quality of available digital data. The purpose of NatCarb is to provide a national view of the carbon capture and storage potential in the U.S. and Canada. The digital spatial database allows users to estimate the amount of CO{sub 2} emitted by sources (such as power plants, refineries and other fossil-fuel-consuming industries) in relation to geologic formations that can provide safe, secure storage sites over long periods of time. The NatCarb project worked to provide all stakeholders with improved online tools for the display and analysis of CO{sub 2} carbon capture and storage data through a single website portal (http://www.natcarb.org/). While the external project is

  8. Characterization of an N-system amino acid transporter expressed in retina and its involvement in glutamine transport.

    PubMed

    Gu, S; Roderick, H L; Camacho, P; Jiang, J X

    2001-06-29

    We report here on the characterization of a mouse N-system amino acid transporter protein, which is involved in the transport of glutamine. This protein of 485 amino acids shares 52% sequence homology with an N-system amino acid transporter, mouse N-system amino acid transporter (mNAT) and its orthologs. Because this protein shares a high degree of sequence homology and functional similarity to mNAT, we named it mNAT2. mNAT2 is predominately expressed in the retina and to a slightly lesser extent in the brain. In the retina, it is located in the axons of ganglion cells in the nerve fiber layer and in the bundles of the optic nerve. Functional analysis of mNAT2 expressed in Xenopus oocytes revealed that the strongest transport activities were specific for l-glutamine. In addition, mNAT2 is a Na(+)- and pH-dependent, high affinity transporter and partially tolerates substitution of Na(+) by Li(+). Additionally, mNAT2 functions as a carrier-mediated transporter that facilitates efflux. The unique expression pattern and selective glutamine transport properties of mNAT2 suggest that it plays a specific role in the uptake of glutamine involved in the generation of the neurotransmitter glutamate in retina. PMID:11325958

  9. Effects of Dietary Factors and the NAT2 Acetylator Status on Gastric Cancer in Koreans

    PubMed Central

    Zhang, Yan Wei; Eom, Sang-Yong; Kim, Yong-Dae; Song, Young-Jin; Yun, Hyo-Yung; Park, Joo-Seung; Youn, Sei-Jin; Kim, Byung Sik; Kim, Heon; Hein, David W.

    2009-01-01

    Environmental dietary carcinogens and genetic polymorphisms in metabolic enzymes have been reported to be risk factors for gastric cancer. This study was undertaken to investigate the effects of the diet, the N-acetyltransferase (NAT) 2 acetylation status, and their interaction on gastric cancer risk. The study population consisted of 471 gastric cancer patients and 471 age- and sex-matched control subjects. NAT2 genotypes were identified using single-nucleotide primer extension reaction methods. Thirty-one alleles related to 12 polymorphism sites were assayed in this study. Significantly increased odds ratios were observed in former smokers (OR = 2.39, 95%CI = 1.57-3.62), heavy drinkers (OR = 1.28, 95%CI = 1.06-1.55), and individuals who eat well-done meat (OR = 1.24, 95%CI = 1.09-1.41). The odds ratios (95% CI) for high intake of kimchi, stews, and soybean paste were 3.27 (2.44-4.37), 1.96 (1.50-2.58), and 1.63 (1.24-2.14), respectively. The NAT2 genotype alone was not associated with gastric cancer risk. A significant gene-environment interaction was observed between environmental carcinogens and NAT2 genotypes. The odds ratios for kimchi, stews, and soybean paste were higher in slow/intermediate acetylators than in rapid acetylators. The odds ratios for slow/intermediate acetylators were 2.28 (95% CI: 1.29-4.04) for light smokers and 3.42 (95% CI: 2.06-5.68) for well-done meat intake. The NAT2 acetylator genotype may be an important modifier of the effects of environmental factors on gastric cancer risk. PMID:19350634

  10. Gender and functional CYP2C and NAT2 polymorphisms determine the metabolic profile of metamizole.

    PubMed

    Martínez, Carmen; Andreu, Inmaculada; Amo, Gemma; Miranda, Miguel A; Esguevillas, Gara; Torres, María José; Blanca-López, Natalia; Blanca, Miguel; García-Martín, Elena; Agúndez, José A G

    2014-12-01

    Metamizole is a pain-killer drug that has been banned in some countries because of its toxicity, but it is still used in many countries due to its effective analgesic and antispasmodic properties. Although large variability in the biodisposition and adverse effects of metamizole are known, factors underlying this variability are poorly understood. We analyzed the urinary recovery of metabolites, as well as the association of these profiles with genetic and non-genetic factors, in a group of 362 healthy individuals. Gender and functional polymorphisms are strongly related to metabolic profiles. N-demethylation of the active metabolite MAA is diminished in carriers of the CYP2C19*2 allele and in NAT2-slow acetylators. Acetylation of the secondary metabolite AA is decreased in men, in drinkers and in NAT2-slow acetylators with a differential effect of NAT2*5 and NAT2*6 alleles. The formylation of MAA is diminished in older subjects and in carriers of defect CYP2C9 and CYP2C19 alleles. Two novel arachidonoyl metabolites were identified for the first time in humans. Women and NAT2-slow acetylators show higher concentrations, whereas the presence of the rapid CYP2C19*17 allele is associated with lower concentrations of these metabolites. All genetic associations show a gene-dose effect. We identified for the first time genetic and non-genetic factors related to the oxidative metabolism of analgesic drug metamizole, as well as new active metabolites in humans. The phenotypic and genetic factors identified in this study have a potential application as biomarkers of metamizole biotransformation and toxicity. PMID:25241292

  11. Interactions of Cigarette Smoking with NAT2 Polymorphisms Impact Rheumatoid Arthritis Risk in African Americans

    PubMed Central

    Mikuls, Ted R.; LeVan, Tricia; Gould, Karen A.; Yu, Fang; Thiele, Geoffrey M.; Bynote, Kimberly K.; Conn, Doyt; Jonas, Beth L.; Callahan, Leigh F.; Smith, Edwin; Brasington, Richard; Moreland, Larry W.; Reynolds, Richard; Gaffo, Angelo; Bridges, S. Louis

    2011-01-01

    Objective To examine whether polymorphisms in genes coding for drug metabolizing enzymes (DMEs) impact rheumatoid arthritis (RA) risk due to cigarette smoking in African Americans. Methods Smoking status was evaluated in African American RA cases and non-RA controls categorized as heavy (≥ 10 pack-years) vs. other. Individuals were genotyped for a homozygous deletion polymorphism in glutathione S-transferase Mu-1 (GSTM1-null) in addition to tagging single nucleotide polymorphisms (SNPs) in N-acetyltransferase (NAT)1, NAT2, and epoxide hydrolase (EPXH1). Associations of genotypes with RA were examined using logistic regression and gene-smoking interactions were assessed. Results There were no significant associations of any DME genotype with RA. After adjustment for multiple comparisons, there were significant additive interactions between heavy smoking and NAT2 SNPs rs9987109 (Padd = 0.000003) and rs1208 (Padd = 0.00001); attributable proportions (APs) due to interaction ranged from 0.61 to 0.67. None of the multiplicative gene-smoking interactions examined remained significant after adjustment for multiple testing in overall disease risk. There was no evidence of significant gene-smoking interactions in analyses of GSTM1-null, NAT1, or EPXH1. DME gene-smoking interactions were similar when cases were limited to anti-citrullinated protein antibody (ACPA) positive individuals. Conclusion Among African Americans, RA risk imposed by heavy smoking appears to be mediated in part by genetic variation in NAT2. While further studies are needed to elucidate mechanisms underpinning these interactions, these SNPs appear to identify African American smokers at a much higher risk for RA with relative risks that are at least two-fold higher compared to non-smokers lacking these risk alleles. PMID:21989592

  12. Uniaxial growth of nonlinear optical active lithium para-nitrophenolate trihydrate single crystal by Sankaranarayanan Ramasamy (SR) method

    NASA Astrophysics Data System (ADS)

    Dinakaran, S.; Jerome Das, S.

    2008-01-01

    Optically transparent bulk single crystal of lithium para-nitrophenolate trihydrate has been grown along (1 1 0) plane using the uniaxial crystal growth method of Sankaranarayanan-Ramasamy with a slight modification in the growth assembly. The crystal was grown with a growth rate of 7 mm per day up to a dimensions of 80 mm length and 12 mm diameter with in a period of 12 days having cylindrical morphology. The grown crystal was confirmed by single crystal X-ray diffraction analysis. The optical transparency of the crystal was observed by UV-Vis-NIR spectral analysis. The mechanical strength of the grown crystal was tested by Vickers microhardness test along the growth plane (1 1 0). Frequency dependent dielectric studies were carried out along the growth axis.

  13. Time-resolved infrared reflectance studies of the dehydration-induced transformation of uranyl nitrate hexahydrate to the trihydrate form

    SciTech Connect

    Johnson, Timothy J.; Sweet, Lucas E.; Meier, David E.; Edward J. Mausolf; Kim, Eunja; Weck, Philippe F.; Buck, Edgar C.; Bruce K. McNamara

    2015-09-08

    Uranyl nitrate is a key species in the nuclear fuel cycle. However, this species is known to exist in different states of hydration, including the hexahydrate ([UO2(NO3)2(H2O)6] often called UNH), the trihydrate [UO2(NO3)2(H2O)3 or UNT], and in very dry environments the dihydrate form [UO2(NO3)2(H2O)2]. Their relative stabilities depend on both water vapor pressure and temperature. In the 1950s and 1960s, the different phases were studied by infrared transmission spectroscopy but were limited both by instrumental resolution and by the ability to prepare the samples for transmission. We have revisited this problem using time-resolved reflectance spectroscopy, which requires no sample preparation and allows dynamic analysis while the sample is exposed to a flow of N2 gas. Samples of known hydration state were prepared and confirmed via X-ray diffraction patterns of known species. In reflectance mode the hexahydrate UO2(NO3)2(H2O)6 has a distinct uranyl asymmetric stretch band at 949.0 cm–1 that shifts to shorter wavelengths and broadens as the sample desiccates and recrystallizes to the trihydrate, first as a shoulder growing in on the blue edge but ultimately results in a doublet band with reflectance peaks at 966 and 957 cm–1. The data are consistent with transformation from UNH to UNT as UNT has two inequivalent UO22+ sites. The dehydration of UO2(NO3)2(H2O)6 to UO2(NO3)2(H2O)3 is both a structural and morphological change that has the lustrous lime green UO2(NO3)2(H2O)6 crystals changing to the matte greenish yellow of the

  14. N-Acetyltransferase 1 (NAT1) Genotype: A Risk Factor for Urinary Bladder Cancer in a Lebanese Population.

    PubMed

    Yassine, Ibrahim A; Kobeissi, Loulou; Jabbour, Michel E; Dhaini, Hassan R

    2012-01-01

    In Lebanon, bladder cancer is the second most incident cancer among men. This study investigates a possible association between N-acetyltransferase 1 (NAT1) genotype, a drug-metabolizing enzyme coding gene, and bladder cancer in Lebanese men. A case-control study (54 cases and 105 hospital-based controls) was conducted in two major hospitals in Beirut. Cases were randomly selected from patients diagnosed in the period of 2002-2008. Controls were conveniently identified and selected from the same settings. Data was collected using interview questionnaire and blood analysis. NAT1 genotypes were determined by PCR-RFLP. Statistical analysis revolved around univariate, bivariate, and multivariate logistic regression models, along with checks for effect modification. Results showed NAT1(∗)14A allele, smoking, occupational exposure to combustion fumes, and prostate-related symptoms, to be risk factors for bladder cancer. The odds of carrying at least one NAT1(∗)14A allele are 7 times higher in cases compared to controls (OR = 7.86, 95% CI: 1.53-40.39). A gene-environment interaction was identified for NAT1(∗)14A allele with occupational exposure to combustion fumes. Among carriers of NAT1(∗)14A allele, the odds of bladder cancer dropped to 2.03 from 3.72. Our study suggests NAT1(∗)14A allele as a possible biomarker for bladder cancer. Further research is recommended to confirm this association. PMID:22956951

  15. N-Acetyltransferase 1 (NAT1) Genotype: A Risk Factor for Urinary Bladder Cancer in a Lebanese Population

    PubMed Central

    Yassine, Ibrahim A.; Kobeissi, Loulou; Jabbour, Michel E.; Dhaini, Hassan R.

    2012-01-01

    In Lebanon, bladder cancer is the second most incident cancer among men. This study investigates a possible association between N-acetyltransferase 1 (NAT1) genotype, a drug-metabolizing enzyme coding gene, and bladder cancer in Lebanese men. A case-control study (54 cases and 105 hospital-based controls) was conducted in two major hospitals in Beirut. Cases were randomly selected from patients diagnosed in the period of 2002–2008. Controls were conveniently identified and selected from the same settings. Data was collected using interview questionnaire and blood analysis. NAT1 genotypes were determined by PCR-RFLP. Statistical analysis revolved around univariate, bivariate, and multivariate logistic regression models, along with checks for effect modification. Results showed NAT1∗14A allele, smoking, occupational exposure to combustion fumes, and prostate-related symptoms, to be risk factors for bladder cancer. The odds of carrying at least one NAT1∗14A allele are 7 times higher in cases compared to controls (OR = 7.86, 95% CI: 1.53–40.39). A gene-environment interaction was identified for NAT1∗14A allele with occupational exposure to combustion fumes. Among carriers of NAT1∗14A allele, the odds of bladder cancer dropped to 2.03 from 3.72. Our study suggests NAT1∗14A allele as a possible biomarker for bladder cancer. Further research is recommended to confirm this association. PMID:22956951

  16. NAT10 regulates p53 activation through acetylating p53 at K120 and ubiquitinating Mdm2.

    PubMed

    Liu, Xiaofeng; Tan, Yuqin; Zhang, Chunfeng; Zhang, Ying; Zhang, Liangliang; Ren, Pengwei; Deng, Hongkui; Luo, Jianyuan; Ke, Yang; Du, Xiaojuan

    2016-03-01

    As a genome guardian, p53 maintains genome stability by arresting cells for damage repair or inducing cell apoptosis to eliminate the damaged cells in stress response. Several nucleolar proteins stabilize p53 by interfering Mdm2-p53 interaction upon cellular stress, while other mechanisms by which nucleolar proteins activate p53 remain to be determined. Here, we identify NAT10 as a novel regulator for p53 activation. NAT10 acetylates p53 at K120 and stabilizes p53 by counteracting Mdm2 action. In addition, NAT10 promotes Mdm2 degradation with its intrinsic E3 ligase activity. After DNA damage, NAT10 translocates to nucleoplasm and activates p53-mediated cell cycle control and apoptosis. Finally, NAT10 inhibits cell proliferation and expression of NAT10 decreases in human colorectal carcinomas. Thus, our data demonstrate that NAT10 plays a critical role in p53 activation via acetylating p53 and counteracting Mdm2 action, providing a novel pathway by which nucleolar protein activates p53 as a cellular stress sensor. PMID:26882543

  17. The NatCarb geoportal: Linking distributed data from the Carbon Sequestration Regional Partnerships

    USGS Publications Warehouse

    Carr, T.R.; Rich, P.M.; Bartley, J.D.

    2007-01-01

    The Department of Energy (DOE) Carbon Sequestration Regional Partnerships are generating the data for a "carbon atlas" of key geospatial data (carbon sources, potential sinks, etc.) required for rapid implementation of carbon sequestration on a broad scale. The NATional CARBon Sequestration Database and Geographic Information System (NatCarb) provides Web-based, nation-wide data access. Distributed computing solutions link partnerships and other publicly accessible repositories of geological, geophysical, natural resource, infrastructure, and environmental data. Data are maintained and enhanced locally, but assembled and accessed through a single geoportal. NatCarb, as a first attempt at a national carbon cyberinfrastructure (NCCI), assembles the data required to address technical and policy challenges of carbon capture and storage. We present a path forward to design and implement a comprehensive and successful NCCI. ?? 2007 The Haworth Press, Inc. All rights reserved.

  18. Fuel ethanol production from corn stover under optimized dilute phosphoric acid pretreatment and enzymatic hydrolysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ethanol is a renewable oxygenated fuel. Dilute acid pretreatment is a promising pretreatment technology for conversion of lignocellulosic biomass to fuel ethanol. Generation of fermentable sugars from corn stover involves pretreatment and enzymatic saccharification. Pretreatment is crucial as nat...

  19. Activation cross-sections of proton induced reactions on natSm up to 65 MeV

    NASA Astrophysics Data System (ADS)

    Tárkányi, F.; Hermanne, A.; Takács, S.; Ditrói, F.; Ignatyuk, A. V.

    2015-03-01

    Activation cross sections for proton induced reactions on Sm are presented for the first time for natSm(p,xn)154,152m2,152m1,152g,150m,150g,149,148,147,146,145Eu, natSm(p,x)153,145Sm, natSm(p,x)151,150,149,148g,148m,146,144,143Pm and natSm(p,x)141Nd up to 65 MeV. The cross sections were measured via activation method by using a stacked-foil irradiation technique and high resolution gamma ray spectroscopy. The results were compared with results of the nuclear reaction codes ALICE, EMPIRE and TALYS (results taken from TENDL libraries). Integral yields of the activation products were calculated from the excitation functions.

  20. The profibrinolytic enzyme subtilisin NAT purified from Bacillus subtilis Cleaves and inactivates plasminogen activator inhibitor type 1.

    PubMed

    Urano, T; Ihara, H; Umemura, K; Suzuki, Y; Oike, M; Akita, S; Tsukamoto, Y; Suzuki, I; Takada, A

    2001-07-01

    In this report, we demonstrate an interaction between subtilisin NAT (formerly designated BSP, or nattokinase), a profibrinolytic serine proteinase from Bacillus subtilis, and plasminogen activator inhibitor 1 (PAI-1). Subtilisin NAT was purified to homogeneity (molecular mass, 27.7 kDa) from a saline extract of B. subtilis (natto). Subtilisin NAT appeared to cleave active recombinant prokaryotic PAI-1 (rpPAI-1) into low molecular weight fragments. Matrix-assisted laser desorption/ionization in combination with time-of-flight mass spectroscopy and peptide sequence analysis revealed that rpPAI-1 was cleaved at its reactive site (P1-P1': Arg(346)-Met(347)). rpPAI-1 lost its specific activity after subtilisin NAT treatment in a dose-dependent manner (0.02-1.0 nm; half-maximal effect at approximately 0.1 nm). Subtilisin NAT dose dependently (0.06-1 nm) enhanced tissue-type plasminogen activator-induced fibrin clot lysis both in the absence of rpPAI-1 (48 +/- 1.4% at 1 nm) and especially in the presence of rpPAI-1 (78 +/- 2.0% at 1 nm). The enhancement observed in the absence of PAI-1 seems to be induced through direct fibrin dissolution by subtilisin NAT. The stronger enhancement by subtilisin NAT of rpPAI-1-enriched fibrin clot lysis seems to involve the cleavage and inactivation of active rpPAI-1. This mechanism is suggested to be important for subtilisin NAT to potentiate fibrinolysis. PMID:11325965

  1. Elevated arylalkylamine-N-acetyltransferase (AA-NAT) gene expression in medial habenular and suprachiasmatic nuclei of hibernating ground squirrels.

    PubMed

    Yu, Erik Z; Hallenbeck, John M; Cai, Decheng; McCarron, Richard M

    2002-06-15

    Hibernation, an adaptive response for energy conservation in mammals, involves a variety of physiological changes. Melatonin is linked with the regulation of core body temperature and intervenes in generating circadian cycles; its role in seasonal (circannual) rhythms of hibernation is explored here. Melatonin is primarily produced in the pineal gland. Since arylalkylamine-N-acetyltransferase (AA-NAT) is the rate-limiting enzyme for synthesizing melatonin, AA-NAT gene expression was investigated to assess the possible role of melatonin in hibernation. The findings presented here utilized combined in situ hybridization and immunohistochemistry methodologies to evaluate the AA-NAT mRNA expression in brains of both hibernating and non-hibernating ground squirrels. Brains were examined for the expression of AA-NAT mRNA using a oligonucleotide AA-NAT probe; antibody against neurofilament-70 (NF-70) was used as a neuronal marker. All hibernating animals expressed significantly (P<0.01) elevated levels of AA-NAT mRNA in both the epithalamic medial habenular nuclei (MHb) area and the hypothalamic suprachiasmatic nuclei (SCN), which is also known as the master biologic clock. These findings represent the first demonstration of the expression of mRNA encoding for AA-NAT in the extra-pineal (i.e. SCN and MHb) sites of thirteen-lined ground squirrels and indicate that the habenular nucleus may be an important supplementary location for melatonin biosynthesis. The data presented here indicate that AA-NAT gene is one of the few specific genes up-regulated during hibernation and suggest that elevation of its expression in SCN and MHb may play an essential role in the generation and maintenance of hibernation. PMID:12191489

  2. Genotype and allele frequencies of isoniazid-metabolizing enzymes NAT2 and GSTM1 in Latvian tuberculosis patients.

    PubMed

    Igumnova, Viktorija; Capligina, Valentina; Krams, Alvils; Cirule, Andra; Elferts, Didzis; Pole, Ilva; Jansone, Inta; Bandere, Dace; Ranka, Renate

    2016-07-01

    Pharmacogenomic testing of tuberculosis drug-metabolizing enzyme genes was proposed as a strategy to identify patients at risk for suboptimal responses to medications. However, variations of the genotype frequencies among ethnic groups exist and new alleles are been identified. The aim of this study was to identify polymorphisms of genes encoding metabolic enzymes NAT2 and GSTM1 in tuberculosis patients in Latvia and to estimate the frequency of NAT2 slow acetylator and GSTM1 null genotypes. In total, 85 DNA samples were genotyped, all individuals were Caucasian. An ethnic heterogeneity reflecting the multiethnic population of the country was observed. 49 patients were Latvians, 30 were Russians and 6 of other ethnicity. In total, 7 NAT2 alleles were identified: *4, *5, *6, *7, *11, *12, * and *13. The most frequent was the slow acetylation allele NAT2*6 (frequency 0.388) followed by the slow acetylation allele NAT2*5 and the rapid acetylation allele NAT2*4 (frequencies 0.306 and 0.194, respectively). The predominance of slow (51.8%) and intermediate (43.5%) acetylators compared with rapid acetylators (4.7%) was observed. The GSTM1 null genotype was detected in 48.2% of tuberculosis patients. When subgroup analysis was performed according to ethnicity, the results showed that neither NAT2 allele frequencies nor GSTM1 null genotype frequency did not differ significantly in TB patients of Latvian or Russian ethnicity. Overall, genotyping results were similar with previous reports of a NAT2 gene variation and GSTM1 null genotype frequency in Caucasians. Our findings have a contribution for the pharmacogenetics-based tuberculosis therapy in Latvia in future. PMID:27236516

  3. Inhibition of angiotensin I converting enzyme by subtilisin NAT (nattokinase) in natto, a Japanese traditional fermented food.

    PubMed

    Murakami, Keiko; Yamanaka, Naoki; Ohnishi, Katsunori; Fukayama, Minoru; Yoshino, Masataka

    2012-06-01

    Angiotensin I converting enzyme (ACE) was inhibited by the culture medium of Bacillus subtilis subsp. natto, which ferments boiled soy beans to natto, a Japanese traditional food. Subtilisin NAT (nattokinase) produced by B. subtilis also inhibited ACE, and the inhibition was markedly stimulated by heat treatment of subtilisin at 120 °C for 15 min. Inhibition of ACE by subtilisin was of a mixed type: the decrease in V(max) and the increase in K(m) value. SDS-polyacrylamide gel electrophoresis showed that heat treatment of subtilisin caused inactivation with fragmentation of the enzyme protein into small peptides. The inhibitory action of subtilisin was not due to an enzymatic action of protease, but may be ascribed to the potent ACE-inhibitory peptides such as LY and FY, amino acid sequences in subtilisin. HPLC-MS analysis of heat-inactivated subtilisin confirmed that LY and FY were liberated by fragmentation of the enzyme. Inhibition of ACE by subtilisin and its degradation peptides such as LY and FY may participate in the suppression of blood pressure by ingestion of natto. PMID:22453301

  4. Individual donor-nucleic acid testing for human immunodeficiency virus-1, hepatitis C virus and hepatitis B virus and its role in blood safety

    PubMed Central

    Kumar, Rajesh; Gupta, Sonia; Kaur, Amarjit; Gupta, Manvi

    2015-01-01

    Background: Transfusion-transmitted infections (TTIs) are one of the biggest threats to blood transfusion safety. Nucleic acid testing (NAT) in blood donor screening has been implemented in many countries to reduce the risk of TTIs. NAT shortens this window period, thereby offering blood centers a much higher sensitivity for detecting viral infections. Aims: The objective was to assess the role of individual donor-NAT (ID-NAT) for human immunodeficiency virus-1 (HIV-1), hepatitis C virus (HCV) and hepatitis B virus (HBV) and its role in blood safety. Materials and Methods: A total of 32978 donations were tested for all three viruses using enzyme-linked immuno-sorbent assay (Vironostika® HIV Ag-Ab, Hepanostika® HCV ultra and hepatitis B surface antigen ultra by Biomerieux) and ID-NAT using Procleix Ultrio plus® Assay (Novartis Diagnostic, USA). All initial NAT reactive samples and serology nonreactive were retested in triplicate and NAT discriminatory assay for HIV-1, HCV and HBV were performed. Results: Of the 32978 samples, 43 (0.13%) were found to be ID-NAT reactive but seronegative. Out of 43, one for HIV-1, 13 for HCV and 27 for HBV were reactive by discriminatory assays. There were two samples that were reactive for both HCV-HBV and counted as HCV-HBV co-infection NAT yield. The prevalence of these viruses in our sample, tested by ID-NAT is 0.06%, 0.71%, and 0.63% for HIV-1, HCV and HBV respectively. The combined NAT yield among blood donors was 1 in 753. Conclusion: ID-NAT testing for HIV-1, HCV and HBV can tremendously improve the efficacy of screening for protecting blood recipient from TTIs. It enables detection of these viruses that were undetected by serological test and thus helped in providing safe blood to the patients. PMID:26420945

  5. Contribution of the N‐acetyltransferase 2 polymorphism NAT2*6A to age‐related hearing impairment

    PubMed Central

    Van Eyken, E; Van Camp, G; Fransen, E; Topsakal, V; Hendrickx, J J; Demeester, K; Van de Heyning, P; Mäki‐Torkko, E; Hannula, S; Sorri, M; Jensen, M; Parving, A; Bille, M; Baur, M; Pfister, M; Bonaconsa, A; Mazzoli, M; Orzan, E; Espeso, A; Stephens, D; Verbruggen, K; Huyghe, J; Dhooge, I; Huygen, P; Kremer, H; Cremers, C W R J; Kunst, S; Manninen, M; Pyykkö, I; Lacava, A; Steffens, M; Wienker, T F; Van Laer, L

    2007-01-01

    Background Age‐related hearing impairment (ARHI) is the most common sensory impairment in older people, affecting 50% of those aged 80 years. The proportion of older people is increasing in the general population, and as a consequence, the number of people affected with ARHI is growing. ARHI is a complex disorder, with both environmental and genetic factors contributing to the disease. The first studies to elucidate these genetic factors were recently performed, resulting in the identification of the first two susceptibility genes for ARHI, NAT2 and KCNQ4. Methods In the present study, the association between ARHI and polymorphisms in genes that contribute to the defence against reactive oxygen species, including GSTT1, GSTM1 and NAT2, was tested. Samples originated from seven different countries and were combined into two test population samples, the general European population and the Finnish population. Two distinct phenotypes for ARHI were studied, Zlow and Zhigh, representing hearing in the low and high frequencies, respectively. Statistical analysis was performed for single polymorphisms (GSTM1, GSTT1, NAT2*5A, NAT2*6A, and NAT2*7A), haplotypes, and gene–environment and gene–gene interactions. Results We found an association between ARHI and GSTT1 and GSTM1 in the Finnish population sample, and with NAT2*6A in the general European population sample. The latter finding replicates previously published data. Conclusion As replication is considered the ultimate proof of true associations in the study of complex disorders, this study provides further support for the involvement of NAT2*6A in ARHI. PMID:17513527

  6. Role of the size of particles of alumina trihydrate filler on the life of RTV silicone rubber coating

    SciTech Connect

    Deng, H.; Hackam, R.; Cherney, E.A. |

    1995-04-01

    The paper reports on a study of the influence of the size of the particles of Alumina trihydrate (ATH) filler on the life of RTV silicone rubber coating in a salt-fog chamber. The particle sizes examined include 1.0, 4.5, 13, 17 and 75{mu}m. The optimum size to give the lowest leakage current and the longest time to failure of the coating is determined. The particle size affects the roughness of the coating. This is determined by a high resolution surface roughness tester and a scanning electron microscope (SEM) examination. The roughness is enhanced after prolonged test in salt-fog. The leakage current affects the amount of silicone fluid on the surface. The amount of silicone fluid present on the surface after exposure to dry-band arcing in salt-fog is a function of the particle size. Measurements of surface roughness, the amount of silicone fluid on the surface and the leakage current combined with theoretical analysis of the heat conduction lead to identification of the mechanisms by which the size of the ATH particle impart resistance to tracking and erosion.

  7. Performance of iron nano particles and bimetallic Ni/Fe nanoparticles in removal of amoxicillin trihydrate from synthetic wastewater.

    PubMed

    Yazdanbakhsh, Ahmad Reza; Daraei, Hasti; Rafiee, Mohamad; Kamali, Hosein

    2016-01-01

    In the present study, the degradation of amoxicillin trihydrate (AMT), using synthesized nanoscale zero-valent iron (nZVI) and bimetallic Fe and Ni nanoparticles stabilized with chitosan (Cs-Fe/Ni), in water was investigated. A central composite design combined with response surface methodology and optimization was utilized for maximizing the AMT reduction by the nanoparticles-water system. The importance of the various variables and their interactions were analyzed using analysis of variance and t-test. The effects of independent parameters were tested and the results showed that the initial concentration of AMT, pH, and nanoparticles dosage were all significant factors. Field-emission scanning electron microscopy images indicated that chitosan acts as a stabilizer preventing the agglomeration of nanoparticles. Also, chitosan and Ni increased the specific surface area of Cs-Fe/Ni. X-ray diffraction confirmed the existence of Fe(0) in fresh samples and the presence of Fe(II) and Fe(III) after the reaction with AMT. This study demonstrates that the nZVI technology could be a promising approach for antibiotic wastewater treatment. PMID:27332846

  8. Combustion of petroleum coke dust as a partial substitute for natural gas and oil in the alumina trihydrate calcination process

    SciTech Connect

    Desgroseillers, B.; Perron, J.; Laurin, P.; Menard, O.; Martin, J.

    1996-10-01

    In the Saguenay region, Alcan operates two coke calcination rotary kilns to supply with calcined coke its prebaked anode and Soderberg paste smelters. The annual production is approximately 220,000 t of calcined coke. For the last few years, the unwanted emissions of under calcined coke dust (UCCD) emitted from the kilns along with the hot gas reaches approximately 16,000 t per year. A maximum of 6,000 t of UCCD are recycled in fabrication processes. In the search of new possibilities to recycle and sell the remaining 10,000 t the possibility of using this UCCD as a heating source ion other processes has emerged, particularly for the calcination of alumina trihydrate. A feasibility study on the combustion as well as a plant trial showed the benefits of burning this UCCD in two 60 t/h capacity calcination units. In fact, appreciable savings in natural gas or oil, as well as increased energetic efficiency (gain of 6%) were observed in the calcination units. Furthermore, the impact on quality of the metallurgical alumina is negligible. These results can be explained partly by the use of a solid combustible which presents longer combustion time compared to natural gas. The combustion zones are therefore extended, favoring the heat transfer to the solid during calcination.

  9. NAT2 and NER genetic variants and sporadic prostate cancer susceptibility in African Americans.

    PubMed

    Hooker, S; Bonilla, C; Akereyeni, F; Ahaghotu, C; Kittles, R A

    2008-01-01

    Prostate cancer is a common malignancy that disproportionately affects African-American men. Environmental factors and variation in genes responsible for chemical and dietary carcinogen metabolism and DNA damage repair may modulate risk. Fourteen single nucleotide polymorphisms in NAT2 and four NER genes (ERCC1, XPF/ERCC4, XPG/ERCC5 and CSB/ERCC6) were genotyped in a case-control study of 254 African-American prostate cancer cases and 301 healthy controls from Washington, DC. Smoking status, BMI, age and genetic ancestry were included as covariates in the association analyses. We found that individuals homozygous for the XPG/ERCC5 -72C/T promoter polymorphism had a significant reduction in risk, for prostate cancer (OR=0.12; 95% CI=0.03-0.48). A haplotype trend regression test also revealed a protective effect for the haplotype bearing the T allele (P=0.003). In silica analyses suggest a functional implication for the promoter variant since it deletes a GCF transcriptional factor-binding site responsible for the downregulation of transcription. The protective effect of the promoter SNP on risk for prostate cancer was independent of smoking. In contrast, none of the SNPs typed for NAT2, ERCC1, ERCC4 and ERCC6 showed significant association with risk. Additional tests for genotype interactions were not significant. We note that there may be other factors, such as dietary exposures, which may modulate prostate cancer risk in combination with genetic variation within the NAT2 and NER genes. Our results, in combination with previous observations of LOH for ERCC5 in prostate tumors, provide further evidence for a role of XPG/ERCC5 in the etiology of prostate cancer. PMID:18026184

  10. Infrared spectroscopic characterization of dehydration and accompanying phase transition behaviors in NAT-topology zeolites

    SciTech Connect

    Wang, Hsiu-Wen; Bishop, David

    2012-01-01

    Relative humidity (PH2O, partial pressure of water)-dependent dehydration and accompanying phase transitions in NAT-topology zeolites (natrolite, scolecite, and mesolite) were studied under controlled temperature and known PH2O conditions by in situ diffuse-reflectance infrared Fourier transform spectroscopy and parallel X-ray powder diffraction. Dehydration was characterized by the disappearance of internal H2O vibrational modes. The loss of H2O molecules caused a sequence of structural transitions in which the host framework transformation path was coupled primarily via the thermal motion of guest Na?/Ca2? cations and H2O molecules. The observation of different interactions of H2O molecules and Na?/Ca2? cations with host aluminosilicate frameworks under highand low-PH2O conditions indicated the development of different local strain fields, arising from cation H2O interactions in NAT-type channels. These strain fields influence the Si O/Al O bond strength and tilting angles within and between tetrahedra as the dehydration temperature is approached. The newly observed infrared bands (at 2,139 cm-1 in natrolite, 2,276 cm-1 in scolecite, and 2,176 and 2,259 cm-1 in mesolite) result from strong cation H2O Al Si framework interactions in NAT-type channels, and these bands can be used to evaluate the energetic evolution of Na?/Ca2? cations before and after phase transitions, especially for scolecite and mesolite. The 2,176 and 2,259 cm-1 absorption bands in mesolite also appear to be related to Na?/Ca2? order disorder that occur when mesolite loses its Ow4 H2O molecules.

  11. Introduction of the HAM-Nat examination – applicants and students admitted to the Medical Faculty in 2012-2014

    PubMed Central

    Werwick, Katrin; Winkler-Stuck, Kirstin; Hampe, Wolfgang; Albrecht, Peggy; Robra, Bernt-Peter

    2015-01-01

    Background/aim: In the 2012/13 winter semester, the Magdeburg Medical Faculty introduced a test of knowledge for the selection of applicants. The Hamburg Assessment Test for Medicine - Natural Sciences (HAM-Nat) comprises a multiple-choice test with questions on the aspects of biology, physics, chemistry and mathematics relevant to medicine, which was specifically developed for the selection of medicine applicants. The aim is to study how the HAM-Nat influences student selection, the reasons why students decide to take the test as part of their application procedure and what expectations they have of their course of study. Methods: The selection procedures applied at the university in 2011 (without HAM-Nat) and in 2012-2014 (with HAM-Nat) are compared. On the basis of the results of exploratory interviews, university entrants in winter semester 2013/2014 participated in a written survey on why they chose their subject and place of study and their expectations of their course of study. Results: No problems were encountered in introducing the extended selection procedure that included the HAM-Nat Test. The HAM-Nat had a great influence on the selection decision. About 65% of the students admitted would not have obtained a place if the decision had been based exclusively on their Abitur grade [grade obtained in the German school-leaving examination]. On average, male applicants obtained better HAM-Nat results than female ones. The questionnaire was answered by 147 out of 191 university entrants (77%). In the case of applicants from Saxony-Anhalt, the principle reasons for choosing the regional capital are its proximity, the social environment offered, good conditions for studying and the feel-good factor at the university. For the majority of applicants, however, particularly applicants from other federal states, the relatively good chances of admission in Magdeburg were the main reason. Conclusion: The Magdeburg Medical Faculty regards the HAM-Nat as a suitable tool

  12. A national look at carbon capture and storage-National carbon sequestration database and geographical information system (NatCarb)

    USGS Publications Warehouse

    Carr, T.R.; Iqbal, A.; Callaghan, N.; Dana-Adkins-Heljeson; Look, K.; Saving, S.; Nelson, K.

    2009-01-01

    The US Department of Energy's Regional Carbon Sequestration Partnerships (RCSPs) are responsible for generating geospatial data for the maps displayed in the Carbon Sequestration Atlas of the United States and Canada. Key geospatial data (carbon sources, potential storage sites, transportation, land use, etc.) are required for the Atlas, and for efficient implementation of carbon sequestration on a national and regional scale. The National Carbon Sequestration Database and Geographical Information System (NatCarb) is a relational database and geographic information system (GIS) that integrates carbon storage data generated and maintained by the RCSPs and various other sources. The purpose of NatCarb is to provide a national view of the carbon capture and storage potential in the U.S. and Canada. The digital spatial database allows users to estimate the amount of CO2 emitted by sources (such as power plants, refineries and other fossil-fuel-consuming industries) in relation to geologic formations that can provide safe, secure storage sites over long periods of time. The NatCarb project is working to provide all stakeholders with improved online tools for the display and analysis of CO2 carbon capture and storage data. NatCarb is organizing and enhancing the critical information about CO2 sources and developing the technology needed to access, query, model, analyze, display, and distribute natural resource data related to carbon management. Data are generated, maintained and enhanced locally at the RCSP level, or at specialized data warehouses, and assembled, accessed, and analyzed in real-time through a single geoportal. NatCarb is a functional demonstration of distributed data-management systems that cross the boundaries between institutions and geographic areas. It forms the first step toward a functioning National Carbon Cyberinfrastructure (NCCI). NatCarb provides access to first-order information to evaluate the costs, economic potential and societal issues of

  13. Genotyping of the polymorphic N-acetyltransferase (NAT2) and loss of heterozygosity in bladder cancer patients.

    PubMed

    Schnakenberg, E; Ehlers, C; Feyerabend, W; Werdin, R; Hübotter, R; Dreikorn, K; Schloot, W

    1998-05-01

    Acetylation is one of the major routes in metabolism and detoxification of a large number of drugs, chemicals and carcinogens. Slow acetylators are said to be more susceptible to developing bladder cancer and because of investigations about tumor risk based on phenotyping procedures, it was our aim to study the distribution of allelic constellations of the N-acetyltransferase (NAT2) by genotyping patients with bladder cancer. We analysed NAT2 gene of blood and tumor DNA from 60 patients with primary bladder cancer and DNA of blood samples from 154 healthy individuals. Using ASO-PCR/RFLP techniques we identified 70% of patients with bladder cancer (n = 42) to be slow acetylators while genotyping of controls resulted in 61% with slow acetylators (n = 94). In addition, dividing bladder cancer patients in males and females the genotype NAT2*5B/NAT2*6A occured with much higher frequencies in males (OR = 4, 95%); CI = 1.8-8.9). Furthermore, investigating bladder cancer tissues we could detect loss of heterozygosity (LOH) in slow and rapid acetylator genotypes. In eleven out of 60 tumor samples (18.3%) we observed allelic loss at the NAT2 locus while in control DNA of blood from the same patients both alleles were still detectable. PMID:9660060

  14. Structures and functions of insect arylalkylamine N-acetyltransferase (iaaNAT); a key enzyme for physiological and behavioral switch in arthropods

    PubMed Central

    Hiragaki, Susumu; Suzuki, Takeshi; Mohamed, Ahmed A. M.; Takeda, Makio

    2015-01-01

    The evolution of N-acetyltransfeases (NATs) seems complex. Vertebrate arylalkylamine N-acetyltransferase (aaNAT) has been extensively studied since it leads to the synthesis of melatonin, a multifunctional neurohormone prevalent in photoreceptor cells, and is known as a chemical token of the night. Melatonin also serves as a scavenger for reactive oxygen species. This is also true with invertebrates. NAT therefore has distinct functional implications in circadian function, as timezymes (aaNAT), and also xenobiotic reactions (arylamine NAT or simply NAT). NATs belong to a broader enzyme group, the GCN5-related N-acetyltransferase superfamily. Due to low sequence homology and a seemingly fast rate of structural differentiation, the nomenclature for NATs can be confusing. The advent of bioinformatics, however, has helped to classify this group of enzymes; vertebrates have two distinct subgroups, the timezyme type and the xenobiotic type, which has a wider substrate range including imidazolamine, pharmacological drugs, environmental toxicants and even histone. Insect aaNAT (iaaNAT) form their own clade in the phylogeny, distinct from vertebrate aaNATs. Arthropods are unique, since the phylum has exoskeleton in which quinones derived from N-acetylated monoamines function in coupling chitin and arthropodins. Monoamine oxidase (MAO) activity is limited in insects, but NAT-mediated degradation prevails. However, unexpectedly iaaNAT occurs not only among arthropods but also among basal deuterostomia, and is therefore more apomorphic. Our analyses illustrate that iaaNATs has unique physiological roles but at the same time it plays a role in a timezyme function, at least in photoperiodism. Photoperiodism has been considered as a function of circadian system but the detailed molecular mechanism is not well understood. We propose a molecular hypothesis for photoperiodism in Antheraea pernyi based on the transcription regulation of NAT interlocked by the circadian system

  15. Novel polymorphism of AA-NAT gene in Indian goat breeds differing in reproductive traits.

    PubMed

    Sharma, R; Ahlawat, S; Tantia, M S

    2015-01-01

    This is the first description of the polymorphisms of arylalkylamine-N-acetyltransferase (AA-NAT) gene in Indian goats with different reproductive traits (twinning percentage and age of sexual maturity). Based on the important role of AA-NAT in reproduction, it is considered as a possible candidate gene for this trait. Two novel synonymous SNPs, C825T (exon2) and C1249T (exon3) were identified. All three possible genotypes (CC, CT and TT) were identified for C825T mutation whereas two genotypes were observed (CC and CT) for C1249T mutation. SNPs C825T and C1249T changed recognition site of restriction enzyme BtsCI (GGA T G) and AciI (C C GC) and thus can be genotyped by the relatively simple and cost effective technique of PCR-RFLP for establishing further association with reproductive traits. Present results add to the meager existing knowledge and extend the spectrum of genetic variation of caprine candidate genes of reproductive traits, which is another step towards improvement of goat genetic resources and breeding. PMID:27175207

  16. Activation cross-sections of deuteron induced reactions on natSm up to 50 MeV

    NASA Astrophysics Data System (ADS)

    Tárkányi, F.; Hermanne, A.; Takács, S.; Ditrói, F.; Csikai, J.; Ignatyuk, A. V.

    2014-08-01

    Activation cross-sections for deuteron induced reactions on Sm are presented for the first time for natSm(d,xn)155,154,152m2,152m1,152g,150m,150g,149,148,147,146Eu, natSm(d,x) 153,145Sm and natSm(d,x)151,150,149,145,144,143Pm up to 50 MeV. The cross-sections were measured by the stacked-foil irradiation technique and high resolution γ-ray spectrometry. The results were compared with results of nuclear reaction codes ALICE-D, EMPIRE-D and TALYS (from TENDL libraries). Integral yields of the products were calculated from the excitation functions.

  17. N-acetyltransferase genotypes and the pharmacokinetics and tolerability of para-aminosalicylic acid in patients with drug-resistant pulmonary tuberculosis.

    PubMed

    Sy, Sherwin K B; de Kock, Lizanne; Diacon, Andreas H; Werely, Cedric J; Xia, Huiming; Rosenkranz, Bernd; van der Merwe, Lize; Donald, Peter R

    2015-07-01

    The aim of this study was to examine the relationships between N-acetyltransferase genotypes, pharmacokinetics, and tolerability of granular slow-release para-aminosalicylic acid (GSR-PAS) in tuberculosis patients. The study was a randomized, two-period, open-label, crossover design wherein each patient received 4 g GSR-PAS twice daily or 8 g once daily alternately. The PAS concentration-time profiles were modeled by a one-compartment disposition model with three transit compartments in series to describe its absorption. Patients' NAT1 and NAT2 genotypes were determined by sequencing and restriction enzyme analysis, respectively. The number of daily vomits was modeled by a Poisson probability mass function. Comparisons of other tolerability measures by regimens, gender, and genotypes were evaluated by a linear mixed-effects model. The covariate effects associated with efavirenz, gender, and NAT1*3, NAT1*14, and NAT2*5 alleles corresponded to 25, 37, -17, -48, and -27% changes, respectively, in oral clearance of PAS. The NAT1*10 allele did not influence drug clearance. The time above the MIC of 1 mg/liter was significantly different between the two regimens but not influenced by the NAT1 or NAT2 genotypes. The occurrence and intensity of intolerance differed little between regimens. Four grams of GSR-PAS twice daily but not 8 g once daily ensured concentrations exceeding the MIC (1 mg/liter) throughout the dosing interval; PAS intolerance was not related to maximum PAS concentrations over the doses studied and was not more frequent after once-daily dosing. We confirm that the slow phenotype conferred by the NAT1*14 and NAT1*3 alleles resulted in higher PAS exposure but found no evidence of increased activity of the NAT1*10 allele. PMID:25963985

  18. N-Acetyltransferase Genotypes and the Pharmacokinetics and Tolerability of para-Aminosalicylic Acid in Patients with Drug-Resistant Pulmonary Tuberculosis

    PubMed Central

    de Kock, Lizanne; Diacon, Andreas H.; Werely, Cedric J.; Xia, Huiming; Rosenkranz, Bernd; van der Merwe, Lize; Donald, Peter R.

    2015-01-01

    The aim of this study was to examine the relationships between N-acetyltransferase genotypes, pharmacokinetics, and tolerability of granular slow-release para-aminosalicylic acid (GSR-PAS) in tuberculosis patients. The study was a randomized, two-period, open-label, crossover design wherein each patient received 4 g GSR-PAS twice daily or 8 g once daily alternately. The PAS concentration-time profiles were modeled by a one-compartment disposition model with three transit compartments in series to describe its absorption. Patients' NAT1 and NAT2 genotypes were determined by sequencing and restriction enzyme analysis, respectively. The number of daily vomits was modeled by a Poisson probability mass function. Comparisons of other tolerability measures by regimens, gender, and genotypes were evaluated by a linear mixed-effects model. The covariate effects associated with efavirenz, gender, and NAT1*3, NAT1*14, and NAT2*5 alleles corresponded to 25, 37, −17, −48, and −27% changes, respectively, in oral clearance of PAS. The NAT1*10 allele did not influence drug clearance. The time above the MIC of 1 mg/liter was significantly different between the two regimens but not influenced by the NAT1 or NAT2 genotypes. The occurrence and intensity of intolerance differed little between regimens. Four grams of GSR-PAS twice daily but not 8 g once daily ensured concentrations exceeding the MIC (1 mg/liter) throughout the dosing interval; PAS intolerance was not related to maximum PAS concentrations over the doses studied and was not more frequent after once-daily dosing. We confirm that the slow phenotype conferred by the NAT1*14 and NAT1*3 alleles resulted in higher PAS exposure but found no evidence of increased activity of the NAT1*10 allele. PMID:25963985

  19. Infrared optical constants of H2O ice, amorphous nitric acid solutions, and nitric acid hydrates

    NASA Technical Reports Server (NTRS)

    Toon, Owen B.; Koehler, Birgit G.; Middlebrook, Ann M.; Tolbert, Margaret A.; Jordon, Joseph

    1994-01-01

    We determined the infrared optical constants of nitric acid trihydrate, nitric acid dihydrate, nitric acid monohydrate, and solid amorphous nitric acid solutions which crystallize to form these hydrates. We have also found the infrared optical constants of H2O ice. We measured the transmission of infrared light throught thin films of varying thickness over the frequency range from about 7000 to 500/cm at temperatures below 200 K. We developed a theory for the transmission of light through a substrate that has thin films on both sides. We used an iterative Kramers-Kronig technique to determine the optical constants which gave the best match between measured transmission spectra and those calculated for a variety of films of different thickness. These optical constants should be useful for calculations of the infrared spectrum of polar stratospheric clouds.

  20. Human NAT10 Is an ATP-dependent RNA Acetyltransferase Responsible for N4-Acetylcytidine Formation in 18 S Ribosomal RNA (rRNA)*

    PubMed Central

    Ito, Satoshi; Horikawa, Sayuri; Suzuki, Tateki; Kawauchi, Hiroki; Tanaka, Yoshikazu; Suzuki, Takeo; Suzuki, Tsutomu

    2014-01-01

    Human N-acetyltransferase 10 (NAT10) is known to be a lysine acetyltransferase that targets microtubules and histones and plays an important role in cell division. NAT10 is highly expressed in malignant tumors, and is also a promising target for therapies against laminopathies and premature aging. Here we report that NAT10 is an ATP-dependent RNA acetyltransferase responsible for formation of N4-acetylcytidine (ac4C) at position 1842 in the terminal helix of mammalian 18 S rRNA. RNAi-mediated knockdown of NAT10 resulted in growth retardation of human cells, and this was accompanied by high-level accumulation of the 30 S precursor of 18 S rRNA, suggesting that ac4C1842 formation catalyzed by NAT10 is involved in rRNA processing and ribosome biogenesis. PMID:25411247

  1. Neutron Elastic and Inelastic Scattering Cross Sections on ^NatFe and ^23Na

    NASA Astrophysics Data System (ADS)

    Kersting, Luke; Lueck, Collin J.; Hicks, S. F.; Crider, B. P.; McEllistrem, M. T.; Peters, E. E.; Vanhoy, J. R.

    2010-10-01

    Neutron elastic and inelastic scattering angular distributions from ^NatFe and ^23Na at incident neutron energies of 3.57 and 3.81 MeV have been measured at the University of Kentucky 7 MV Van de Graaff laboratory using neutron time-of-flight techniques. The neutron beam was produced using the ^3H(p,n)He^3reaction. The scattered neutrons were detected at angles between 20 and 150 in 10 intervals with a hexafluorbenzene detector located approximately 3 m from the scattering samples. Neutron scattering differential cross sections were deduced. These cross sections and their uncertainties are important for understanding neutron-induced reactions in fission reactors and are important for fission reactor criticality calculations.

  2. The Legacy of Nat Sternberg: The Genesis of Cre-lox Technology.

    PubMed

    Yarmolinsky, Michael; Hoess, Ronald

    2015-11-01

    Cre-lox of bacteriophage P1 has become one of the most widely used tools for genetic engineering in eukaryotes. The origins of this tool date to more than 30 years ago when Nat L. Sternberg discovered the recombinase, Cre, and its specific locus of crossover, lox, while studying the maintenance of bacteriophage P1 as a stable plasmid. Recombinations mediated by Cre assist in cyclization of the DNA of infecting phage and in resolution of prophage multimers created by generalized recombination. Early in vitro work demonstrated that, although it shares similarities with the well-characterized bacteriophage λ integration, Cre-lox is in many ways far simpler in its requirements for carrying out recombination. These features would prove critical for its development as a powerful and versatile tool in genetic engineering. We review the history of the discovery and characterization of Cre-lox and touch upon the present direction of Cre-lox research. PMID:26958905

  3. Measurement of excitation functions in alpha induced reactions on natCu

    NASA Astrophysics Data System (ADS)

    Shahid, Muhammad; Kim, Kwangsoo; Kim, Guinyun; Zaman, Muhammad; Nadeem, Muhammad

    2015-09-01

    The excitation functions of 66,67,68Ga, 62,63,65Zn, 61,64Cu, and 58,60Co radionuclides in the natCu(α, x) reaction were measured in the energy range from 15 to 42 MeV by using a stacked-foil activation method at the MC-50 cyclotron of the Korean Institute of Radiological and Medical Sciences. The measured results were compared with the literature data as well as the theoretical values obtained from the TENDL-2013 and TENDL-2014 libraries based on the TALYS-1.6 code. The integral yields for thick targets of the produced radionuclides were also determined from the measured excitation functions and the stopping power of natural copper.

  4. GSTM1 null and NAT2 slow acetylation genotypes, smoking intensity and bladder cancer risk: results from the New England bladder cancer study and NAT2 meta-analysis.

    PubMed

    Moore, L E; Baris, D R; Figueroa, J D; Garcia-Closas, M; Karagas, M R; Schwenn, M R; Johnson, A T; Lubin, J H; Hein, D W; Dagnall, C L; Colt, J S; Kida, M; Jones, M A; Schned, A R; Cherala, S S; Chanock, S J; Cantor, K P; Silverman, D T; Rothman, N

    2011-02-01

    Associations between bladder cancer risk and NAT2 and GSTM1 polymorphisms have emerged as some of the most consistent findings in the genetic epidemiology of common metabolic polymorphisms and cancer, but their interaction with tobacco use, intensity and duration remain unclear. In a New England population-based case-control study of urothelial carcinoma, we collected mouthwash samples from 1088 of 1171 cases (92.9%) and 1282 of 1418 controls (91.2%) for genotype analysis of GSTM1, GSTT1 and NAT2 polymorphisms. Odds ratios and 95% confidence intervals of bladder cancer among New England Bladder Cancer Study subjects with one or two inactive GSTM1 alleles (i.e. the 'null' genotype) were 1.26 (0.85-1.88) and 1.54 (1.05-2.25), respectively (P-trend = 0.008), compared with those with two active copies. GSTT1 inactive alleles were not associated with risk. NAT2 slow acetylation status was not associated with risk among never (1.04; 0.71-1.51), former (0.95; 0.75-1.20) or current smokers (1.33; 0.91-1.95); however, a relationship emerged when smoking intensity was evaluated. Among slow acetylators who ever smoked at least 40 cigarettes/day, risk was elevated among ever (1.82; 1.14-2.91, P-interaction = 0.07) and current heavy smokers (3.16; 1.22-8.19, P-interaction = 0.03) compared with rapid acetylators in each category; but was not observed at lower intensities. In contrast, the effect of GSTM1-null genotype was not greater among smokers, regardless of intensity. Meta-analysis of the NAT2 associations with bladder cancer showed a highly significant relationship. Findings from this large USA population-based study provided evidence that the NAT2 slow acetylation genotype interacts with tobacco smoking as a function of exposure intensity. PMID:21037224

  5. The results of nucleic acid testing in remunerated and non-remunerated blood donors in Lithuania

    PubMed Central

    Kalibatas, Vytenis; Kalibatienė, Lina

    2014-01-01

    Background In Lithuania, governmentally covered remuneration for whole blood donations prevails. Donors may choose to accept or reject the remuneration. The purpose of this study was to compare the rate of nucleic acid testing (NAT) discriminatory-positive markers for human immunodeficiency virus-1 (HIV-1), hepatitis B virus (HBV) and hepatitis C virus (HCV) in seronegative, first-time and repeat, remunerated and non-remunerated donations at the National Blood Centre in Lithuania during the period from 2005 to 2010. Materials and methods All seronegative whole blood and blood component donations were individually analysed by NAT for HIV-1, HBV and HCV. Only discriminatory-positive NAT were classified. The prevalence of discriminatory-positive NAT per 100,000 donations in the donor groups and the odds ratios comparing the remunerated and non-remunerated donations were determined. Results Significant differences were observed for HBV NAT results: 47.42 and 26.29 per 100,000 remunerated first-time and repeat donations, respectively, compared to 10.6 and 3.58 per 100,000 non-remunerated first-time and repeat, seronegative donations, respectively. The differences were also significant for HCV NAT results: 47.42 and 51.99 for remunerated first-time and repeat donations, respectively, compared to 2.12 and 0 per 100,000 non-remunerated first-time and repeat, seronegative donations, respectively. No seronegative, discriminatory-positive NAT HIV case was found. The odds of discriminatory HBV and HCV NAT positive results were statistically significantly higher for both first-time and repeat remunerated donations compared to first-time and repeat non-remunerated donations. Discussion First-time and repeat remunerated seronegative donations were associated with a statistically significantly higher prevalence and odds for discriminatory-positive HBV and HCV NAT results compared to first-time and repeat non-remunerated donations at the National Blood Centre in Lithuania. PMID

  6. Experimental cross-sections for proton-induced nuclear reactions on natMo

    NASA Astrophysics Data System (ADS)

    Červenák, Jaroslav; Lebeda, Ondřej

    2016-08-01

    In the framework of the Co-ordinated Research Project of the IAEA, we measured in detail cross-sections of the nuclear reactions natMo(p,x)93gTc, 93mTc, 93m+gTc, 94gTc, 94mTc, 95gTc, 95mTc, 96m+gTc, 97mTc, 99mTc, 90Mo, 93mMo, 99Mo, 88gNb, 88mNb, 89gNb, 89mNb, 90m+gNb, 90m+gNbcum, 91mNb, 92mNb, 95gNb, 95mNb, 95m+gNb, 96Nb, 97m+gNb, 88m+gZrcum and 89m+gZrcum in the energy range of 6.9-35.8 MeV. The data for formation of 97mTc, 88gNb, 88mNb and 89mNb are reported for the first time. The obtained results were compared to the prediction of the nuclear reaction model code TALYS adopted from the TENDL-2015 library and to the previously published cross-sections. The thick target yields for all the radionuclides were calculated from the measured data. We suggest recommended cross-sections and thick target yields for the 100Mo(p,2n)99mTc, 100Mo(p,x)99Mo and natMo(p,x)96m+gTc nuclear reactions deduced from the selected experimental data.

  7. 14 CFR Appendix C to Part 91 - Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 2 2014-01-01 2014-01-01 false Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace C Appendix C to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND...

  8. 14 CFR Appendix C to Part 91 - Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 2 2012-01-01 2012-01-01 false Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace C Appendix C to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND...

  9. 14 CFR Appendix C to Part 91 - Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 2 2013-01-01 2013-01-01 false Operations in the North Atlantic (NAT) Minimum Navigation Performance Specifications (MNPS) Airspace C Appendix C to Part 91 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIR TRAFFIC AND...

  10. N-acetyltransferase (nat) Is a Critical Conjunct of Photoperiodism between the Circadian System and Endocrine Axis in Antheraea pernyi

    PubMed Central

    Bembenek, Jadwiga; Hiragaki, Susumu; Suzuki, Takeshi; Takeda, Makio

    2014-01-01

    Since its discovery in 1923, the biology of photoperiodism remains a mystery in many ways. We sought the link connecting the circadian system to an endocrine switch, using Antheraea pernyi. PER-, CLK- and CYC-ir were co-expressed in two pairs of dorsolateral neurons of the protocerebrum, suggesting that these are the circadian neurons that also express melatonin-, NAT- and HIOMT-ir. The results suggest that a melatonin pathway is present in the circadian neurons. Melatonin receptor (MT2 or MEL-1B-R)-ir in PTTH-ir neurons juxtaposing clock neurons suggests that melatonin gates PTTH release. RIA showed a melatonin rhythm with a peak four hours after lights off in adult brain both under LD16∶8 (LD) and LD12∶12 (SD), and both the peak and the baseline levels were higher under LD than SD, suggesting a photoperiodic influence. When pupae in diapause were exposed to 10 cycles of LD, or stored at 4°C for 4 months under constant darkness, an increase of NAT activity was observed when PTTH released ecdysone. DNA sequence upstream of nat contained E-boxes to which CYC/CLK could bind, and nat transcription was turned off by clk or cyc dsRNA. dsRNANAT caused dysfunction of photoperiodism. dsRNAPER upregulated nat transcription as anticipated, based on findings in the Drosophila melanogaster circadian system. Transcription of nat, cyc and clk peaked at ZT12. RIA showed that dsRNANAT decreased melatonin while dsRNAPER increased melatonin. Thus nat, a clock controlled gene, is the critical link between the circadian clock and endocrine switch. MT-binding may release PTTH, resulting in termination of diapause. This study thus examined all of the basic functional units from the clock: a photoperiodic counter as an accumulator of mRNANAT, to endocrine switch for photoperiodism in A. pernyi showing this system is self-complete without additional device especially for photoperiodism. PMID:24667367

  11. Homology modelling and structural analysis of human arylamine N-acetyltransferase NAT1: evidence for the conservation of a cysteine protease catalytic domain and an active-site loop.

    PubMed Central

    Rodrigues-Lima, F; Deloménie, C; Goodfellow, G H; Grant, D M; Dupret, J M

    2001-01-01

    Arylamine N-acetyltransferases (EC 2.3.1.5) (NATs) catalyse the biotransformation of many primary arylamines, hydrazines and their N-hydroxylated metabolites, thereby playing an important role in both the detoxification and metabolic activation of numerous xenobiotics. The recently published crystal structure of the Salmonella typhimurium NAT (StNAT) revealed the existence of a cysteine protease-like (Cys-His-Asp) catalytic triad. In the present study, a three-dimensional homology model of human NAT1, based upon the crystal structure of StNAT [Sinclair, Sandy, Delgoda, Sim and Noble (2000) Nat. Struct. Biol. 7, 560-564], is demonstrated. Alignment of StNAT and NAT1, together with secondary structure predictions, have defined a consensus region (residues 29-131) in which 37% of the residues are conserved. Homology modelling provided a good quality model of the corresponding region in human NAT1. The location of the catalytic triad was found to be identical in StNAT and NAT1. Comparison of active-site structural elements revealed that a similar length loop is conserved in both species (residues 122-131 in NAT1 model and residues 122-133 in StNAT). This observation may explain the involvement of residues 125, 127 and 129 in human NAT substrate selectivity. Our model, and the fact that cysteine protease inhibitors do not affect the activity of NAT1, suggests that human NATs may have adapted a common catalytic mechanism from cysteine proteases to accommodate it for acetyl-transfer reactions. PMID:11368758

  12. MeIQx-induced DNA adduct formation and mutagenesis in DNA repair deficient CHO cells expressing human CYP1A1 and rapid or slow acetylator NAT2

    PubMed Central

    Bendaly, Jean; Zhao, Shuang; Neale, Jason R.; Metry, Kristin J.; Doll, Mark A.; States, J. Christopher; Pierce, William M.; Hein, David W.

    2007-01-01

    2-Amino-3,8-dimethylimidazo-[4,5-f]quinoxaline (MeIQx) is one of the most potent and abundant mutagens in the western diet. Bioactivation includes N-hydroxylation catalyzed by cytochrome P450s followed by O-acetylation catalyzed by N-acetyltransferase 2 (NAT2). Nucleotide excision repair-deficient chinese hamster ovary (CHO) cells were constructed by stable transfection of human cytochrome P4501A1 (CYP1A1) and a single copy of either NAT2*4 (rapid acetylator) or NAT2*5B (slow acetylator) alleles. CYP1A1 and NAT2 catalytic activities were undetectable in untransfected CHO cell lines. CYP1A1 activity did not differ significantly (p > 0.05) among the CYP1A1-transfected cell lines. Cells transfected with NAT2*4 had significantly higher levels of sulfamethazine N-acetyltransferase (p = 0.0001) and N-hydroxy-MeIQx O-acetyltransferase (p = 0.0093) catalytic activity than cells transfected with NAT2*5B. Only cells transfected with both CYP1A1 and NAT2*4 showed concentration-dependent cytotoxicity and hypoxanthine phosphoribosyl transferase (hprt) mutagenesis following MeIQx treatment. dG-C8-MeIQx was the primary DNA adduct formed and levels were dose-dependent in each cell line and in the order: untransfected < transfected with CYP1A1 < transfected with CYP1A1 & NAT2*5B < transfected with CYP1A1 & NAT2*4. MeIQx DNA adduct levels were significantly higher (p < 0.001) in CYP1A1/NAT2*4 than CYP1A1/NAT2*5B cells at all concentrations of MeIQx tested. MeIQx-induced DNA adduct levels correlated very highly (r2 = 0.88) with MeIQx-induced mutants. These results strongly support extrahepatic activation of MeIQx by CYP1A1 and a robust effect of human NAT2 genetic polymorphism on MeIQx –induced DNA adducts and mutagenesis. The results provide laboratory-based support for epidemiological studies reporting higher frequency of heterocyclic amine-related cancers in rapid NAT2 acetylators. PMID:17627018

  13. Implementation of an HIV-1 Triple-Target NAT Assay in the Routine Screening at Three German Red Cross Blood Centres

    PubMed Central

    Zolt, Silke De; Thermann, Rolf; Bangsow, Thorsten; Pichl, Lutz; Müller, Benjamin; Jork, Christine; Weber-Schehl, Marijke; Hedges, Doris; Schupp, Ingo; Unverzagt, Patrick; de Rue, Katrin; Roth, W. Kurt

    2016-01-01

    Summary Background Blood product safety was significantly improved by the introduction of NAT testing in the late 1990s, resulting in a strong decrease of transfusion-transmitted infections (TTIs). Due to the occurrence of HIV-1 NAT test failures as a consequence of mismatch mutations in the amplicon regions of mono-target NAT assays, the Paul Ehrlich Institute mandated the implementation of multi-target NAT assays for HIV-1 in 2014. Commercial suppliers mostly developed dual-target NAT assays, with only one implementing a triple-target NAT assay. Methods The HIV-1 triple-target NAT assay v3 (GFE Blut) was tested on mutated specimens and synthetic DNA bearing mutations that resulted in sample underquantification or false-negative test results. In addition, data from 2 years routine testing at three German Red Cross Blood centres were analysed. Results The HIV-1 triple-target PCR could compensate for all mutations tested and could compensate the loss of one amplicon without a significant loss of sensitivity. Data from 2 years routine testing showed a solid performance. Conclusion The HIV-1 triple-target v3 assay (GFE Blut) can compensate mutations in target sequences better than a dual-target assay and is applicable to high-throughput screening, thus increasing blood product safety. PMID:27403090

  14. The Molecular Basis for Histone H4- and H2A-Specific Amino-Terminal Acetylation by NatD

    PubMed Central

    Magin, Robert S.; Liszczak, Glen P.; Marmorstein, Ronen

    2014-01-01

    SUMMARY N-terminal acetylation is among the most common protein modifications in eukaryotes and is mediated by evolutionarily conserved N-terminal acetyltransferases (NATs). NatD is among the most selective NATs; its only known substrates are histones H4 and H2A, containing the N-terminal sequence SGRGK in humans. Here we characterize the molecular basis for substrate-specific acetylation by NatD by reporting its crystal structure bound to cognate substrates and performing related biochemical studies. A novel N-terminal segment wraps around the catalytic core domain to make stabilizing interactions, and the α1-α2 and β6-β7 loops adopt novel conformations to properly orient the histone N termini in the binding site. Ser1 and Arg3 of the histone make extensive contacts to highly conserved NatD residues in the substrate binding pocket, and flanking glycine residues also appear to contribute to substrate-specific binding by NatD, together defining a Ser-Gly-Arg-Gly recognition sequence. These studies have implications for understanding substrate-specific acetylation by NAT enzymes. PMID:25619998

  15. Interaction between Red Meat Intake and NAT2 Genotype in Increasing the Risk of Colorectal Cancer in Japanese and African Americans

    PubMed Central

    Wang, Hansong; Iwasaki, Motoki; Haiman, Christopher A.; Kono, Suminori; Wilkens, Lynne R.; Keku, Temitope O.; Berndt, Sonja I.; Tsugane, Shoichiro; Le Marchand, Loïc

    2015-01-01

    Heterocyclic aromatic amines formed in cooked meat may be an underlying mechanism for the red meat-colorectal cancer (CRC) association. These compounds require bioactivaction by N-acetyltransferase 2 (NAT2). An interaction effect between red meat consumption and NAT2 in increasing CRC risk has been inconsistently reported in whites. We investigated this interaction in two populations in which the high-activity rapid NAT2 phenotype is 10- and 2-fold more common than in whites. We meta-analyzed four studies of Japanese (2,217 cases, 3,788 controls) and three studies of African Americans (527 cases, 4,527 controls). NAT2 phenotype was inferred from an optimized seven-SNP genotyping panel. Processed and total red meat intakes were associated with an increased CRC risk in Japanese and in both ethnic groups combined (P’s ≤ 0.002). We observed an interaction between processed meat intake and NAT2 in Japanese (P = 0.04), African Americans (P = 0.02), and in both groups combined (P = 0.006). The association of processed meat with CRC was strongest among individuals with the rapid NAT2 phenotype (combined analysis, OR for highest vs. lowest quartile: 1.62, 95% CI: 1.28–2.05; Ptrend = 8.0×10−5), intermediate among those with the intermediate NAT2 phenotype (1.29, 95% CI: 1.05–1.59; Ptrend = 0.05) and null among those with the slow phenotype (Ptrend = 0.45). A similar interaction was found for NAT2 and total red meat (Pinteraction = 0.03). Our findings support a role for NAT2 in modifying the association between red meat consumption and CRC in Japanese and African Americans. PMID:26683305

  16. Interaction between Red Meat Intake and NAT2 Genotype in Increasing the Risk of Colorectal Cancer in Japanese and African Americans.

    PubMed

    Wang, Hansong; Iwasaki, Motoki; Haiman, Christopher A; Kono, Suminori; Wilkens, Lynne R; Keku, Temitope O; Berndt, Sonja I; Tsugane, Shoichiro; Le Marchand, Loïc

    2015-01-01

    Heterocyclic aromatic amines formed in cooked meat may be an underlying mechanism for the red meat-colorectal cancer (CRC) association. These compounds require bioactivaction by N-acetyltransferase 2 (NAT2). An interaction effect between red meat consumption and NAT2 in increasing CRC risk has been inconsistently reported in whites. We investigated this interaction in two populations in which the high-activity rapid NAT2 phenotype is 10- and 2-fold more common than in whites. We meta-analyzed four studies of Japanese (2,217 cases, 3,788 controls) and three studies of African Americans (527 cases, 4,527 controls). NAT2 phenotype was inferred from an optimized seven-SNP genotyping panel. Processed and total red meat intakes were associated with an increased CRC risk in Japanese and in both ethnic groups combined (P's ≤ 0.002). We observed an interaction between processed meat intake and NAT2 in Japanese (P = 0.04), African Americans (P = 0.02), and in both groups combined (P = 0.006). The association of processed meat with CRC was strongest among individuals with the rapid NAT2 phenotype (combined analysis, OR for highest vs. lowest quartile: 1.62, 95% CI: 1.28-2.05; Ptrend = 8.0×10-5), intermediate among those with the intermediate NAT2 phenotype (1.29, 95% CI: 1.05-1.59; Ptrend = 0.05) and null among those with the slow phenotype (Ptrend = 0.45). A similar interaction was found for NAT2 and total red meat (Pinteraction = 0.03). Our findings support a role for NAT2 in modifying the association between red meat consumption and CRC in Japanese and African Americans. PMID:26683305

  17. Enhancing international earth science competence in natural hazards through 'geoNatHaz

    NASA Astrophysics Data System (ADS)

    Giardino, Marco; Clague, John J.

    2010-05-01

    "geoNatHaz" is a Transatlantic Exchange Partnership project (TEP 2009-2012) within the framework of the EU-Canada programme for co-operation in higher education, training, and youth. The project is structured to improve knowledge and skills required to assess and manage natural hazards in mountain regions. It provides student exchanges between European and Canadian universities in order to enhance international competence in natural hazard research. The university consortium is led by Simon Fraser University (Canada) and Università degli studi di Torino (Italy). Partner universities include the University of British Columbia, Queen's University, Università di Bologna, Université de Savoie, and the University of Athens. Université de Lausanne (Switzerland) supports the geoNatHaz advisory board through its bilateral agreements with Canadian partner universities. The geoNatHaz project promotes cross-cultural understanding and internationalization of university natural hazard curricula through common lectures, laboratory exercises, and field activities. Forty graduate students from the seven Canadian and European partner universities will benefit from the project between 2009 and 2012. Some students enrolled in graduate-level earth science and geologic engineering programs spend up to five months at the partner universities, taking courses and participating in research teams under the direction of project scientists. Other students engage in short-term (four-week) exchanges involving training in classic natural hazard case-studies in mountain regions of Canada and Europe. Joint courses are delivered in English, but complementary cultural activities are offered in the languages of the host countries. Supporting organizations offer internships and technical and scientific support. Students benefit from work-study programs with industry partners. Supporting organizations include government departments and agencies (Geological Survey of Canada; CNR-IRPI National

  18. Genotyping NAT2 with only two SNPs (rs1041983 and rs1801280) outperforms the tagging SNP rs1495741 and is equivalent to the conventional 7-SNP NAT2 genotype.

    PubMed

    Selinski, Silvia; Blaszkewicz, Meinolf; Lehmann, Marie-Louise; Ovsiannikov, Daniel; Moormann, Oliver; Guballa, Christoph; Kress, Alexander; Truss, Michael C; Gerullis, Holger; Otto, Thomas; Barski, Dimitri; Niegisch, Günter; Albers, Peter; Frees, Sebastian; Brenner, Walburgis; Thüroff, Joachim W; Angeli-Greaves, Miriam; Seidel, Thilo; Roth, Gerhard; Dietrich, Holger; Ebbinghaus, Rainer; Prager, Hans M; Bolt, Hermann M; Falkenstein, Michael; Zimmermann, Anna; Klein, Torsten; Reckwitz, Thomas; Roemer, Hermann C; Löhlein, Dietrich; Weistenhöfer, Wobbeke; Schöps, Wolfgang; Hassan Rizvi, Syed Adibul; Aslam, Muhammad; Bánfi, Gergely; Romics, Imre; Steffens, Michael; Ekici, Arif B; Winterpacht, Andreas; Ickstadt, Katja; Schwender, Holger; Hengstler, Jan G; Golka, Klaus

    2011-10-01

    Genotyping N-acetyltransferase 2 (NAT2) is of high relevance for individualized dosing of antituberculosis drugs and bladder cancer epidemiology. In this study we compared a recently published tagging single nucleotide polymorphism (SNP) (rs1495741) to the conventional 7-SNP genotype (G191A, C282T, T341C, C481T, G590A, A803G and G857A haplotype pairs) and systematically analysed if novel SNP combinations outperform the latter. For this purpose, we studied 3177 individuals by PCR and phenotyped 344 individuals by the caffeine test. Although the tagSNP and the 7-SNP genotype showed a high degree of correlation (R=0.933, P<0.0001) the 7-SNP genotype nevertheless outperformed the tagging SNP with respect to specificity (1.0 vs. 0.9444, P=0.0065). Considering all possible SNP combinations in a receiver operating characteristic analysis we identified a 2-SNP genotype (C282T, T341C) that outperformed the tagging SNP and was equivalent to the 7-SNP genotype. The 2-SNP genotype predicted the correct phenotype with a sensitivity of 0.8643 and a specificity of 1.0. In addition, it predicted the 7-SNP genotype with sensitivity and specificity of 0.9993 and 0.9880, respectively. The prediction of the NAT2 genotype by the 2-SNP genotype performed similar in populations of Caucasian, Venezuelan and Pakistani background. A 2-SNP genotype predicts NAT2 phenotypes with similar sensitivity and specificity as the conventional 7-SNP genotype. This procedure represents a facilitation in individualized dosing of NAT2 substrates without losing sensitivity or specificity. PMID:21750470

  19. Synthesis, thermal and spectroscopic behaviors of metal-drug complexes: La(III), Ce(III), Sm(III) and Y(III) amoxicillin trihydrate antibiotic drug complexes

    NASA Astrophysics Data System (ADS)

    Refat, Moamen S.; Al-Maydama, Hussein M. A.; Al-Azab, Fathi M.; Amin, Ragab R.; Jamil, Yasmin M. S.

    2014-07-01

    The metal complexes of Amoxicillin trihydrate with La(III), Ce(III), Sm(III) and Y(III) are synthesized with 1:1 (metal:Amox) molar ratio. The suggested formula structures of the complexes are based on the results of the elemental analyses, molar conductivity, (infrared, UV-visible and fluorescence) spectra, effective magnetic moment in Bohr magnetons, as well as the thermal analysis (TG), and characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). The results obtained suggested that Amoxicillin reacted with metal ions as tridentate ligands, coordinating the metal ion through its amino, imino, and β-lactamic carbonyl. The kinetic thermodynamic parameters such as: Ea, ΔH*, ΔS* and ΔG* were estimated from the DTG curves.

  20. Probability density functions characterizing PSC particle size distribution parameters for NAT and STS derived from in situ measurements between 1989 and 2010 above McMurdo Station, Antarctica, and between 1991-2004 above Kiruna, Sweden

    NASA Astrophysics Data System (ADS)

    Deshler, Terry

    2016-04-01

    Balloon-borne optical particle counters were used to make in situ size resolved particle concentration measurements within polar stratospheric clouds (PSCs) over 20 years in the Antarctic and over 10 years in the Arctic. The measurements were made primarily during the late winter in the Antarctic and in the early and mid-winter in the Arctic. Measurements in early and mid-winter were also made during 5 years in the Antarctic. For the analysis bimodal lognormal size distributions are fit to 250 meter averages of the particle concentration data. The characteristics of these fits, along with temperature, water and nitric acid vapor mixing ratios, are used to classify the PSC observations as either NAT, STS, ice, or some mixture of these. The vapor mixing ratios are obtained from satellite when possible, otherwise assumptions are made. This classification of the data is used to construct probability density functions for NAT, STS, and ice number concentration, median radius and distribution width for mid and late winter clouds in the Antarctic and for early and mid-winter clouds in the Arctic. Additional analysis is focused on characterizing the temperature histories associated with the particle classes and the different time periods. The results from theses analyses will be presented, and should be useful to set bounds for retrievals of PSC properties from remote measurements, and to constrain model representations of PSCs.

  1. Arylamine N-acetyltransferase (NAT2) mutations and their allelic linkage in unrelated caucasian individuals: Correlation with phenotypic activity

    SciTech Connect

    Cascorbi, I.; Drakoulis, N.; Brockmoeller, J.

    1995-09-01

    The polymorphic arylamine N-acetyltransferase (NAT2; EC2.3.1.5) is supposed to be a susceptibility factor for several drug side effects and certain malignancies. A group of 844 unrelated German subjects was genotyped for their acetylation type, and 563 of them were also phenotyped. Seven mutations of the NAT2 gene were evaluated by allele-specific PCR (mutation 341C to T) and PCR-RFLP for mutations at nt positions 191, 282, 481, 590, 803, and 857. From the mutation pattern eight different alleles, including the wild type coding for rapid acetylation and seven alleles coding for slow phenotype, were determined. Four hundred ninety-seven subjects had a genotype of slow acetylation (58.9%; 95% confidence limits 55.5%-62.2%). Phenotypic acetylation capacity was expressed as the ratio of 5-acetylamino-6-formylamino-3-methyluracil and 1-methylxanthine in urine after caffeine intake. Some 6.7% of the cases deviated in genotype and phenotype, but sequencing DNA of these probands revealed no new mutations. Furthermore, linkage pattern of the mutations was always confirmed, as tested in 533 subjects. In vivo acetylation capacity of homozygous wild-type subjects (NAT2{sup *}4/{sup *}4) was significantly higher than in heterozygous genotypes (P = .001). All mutant alleles showed low in vivo acetylation capacities, including the previously not-yet-defined alleles {sup *}5A, {sup *}5C, and {sup *}13. Moreover, distinct slow genotypes differed significantly among each other, as reflected in lower acetylation capacity of {sup *}6A, {sup *}7B, and {sup *}13 alleles than the group of {sup *}5 alleles. The study demonstrated differential phenotypic activity of various NAT2 genes and gives a solid basis for clinical and molecular-epidemiological investigations. 34 refs., 4 figs., 7 tabs.

  2. MT1 receptor expression and AA-NAT activity in lymphatic tissue following melatonin administration in male golden hamster.

    PubMed

    Vishwas, Dipanshu Kumar; Haldar, Chandana

    2014-09-01

    Exogenous melatonin as a marker of the chemical expression of darkness is playing a key role in the synchronization of circadian functions and seasonal biological rhythms. Our study was designed to elucidate whether melatonin treatment can modulate the melatonin synthesis via the rate limiting enzyme arylalkylamine-N-acetyltransferase (AA-NAT) in spleen, thymus and bone marrow thereby the proliferation rate of splenocytes, thymocytes and bone marrow mononuclear cells (BM-MNCs) of golden hamsters. The AA-NAT activity in different lymphoid tissue documented the synthesis of melatonin in those organs. Exogenous melatonin treatment to hamsters enhanced the AA-NAT activity in spleen and thymus along with an increase in the inflammatory response by DTH reactions that could be related to the increased level of interleukin-2 and IFN-γ by T lymphocytes in serum/culture medium, proliferation rate and expression of melatonin membrane receptor MT(1). Thus, the relevance of melatonin synthesis by lymphatic tissues might be maintaining surveillance and local defence responses. PMID:25023124

  3. Structure and function of human Naa60 (NatF), a Golgi-localized bi-functional acetyltransferase

    PubMed Central

    Chen, Ji-Yun; Liu, Liang; Cao, Chun-Ling; Li, Mei-Jun; Tan, Kemin; Yang, Xiaohan; Yun, Cai-Hong

    2016-01-01

    N-terminal acetylation (Nt-acetylation), carried out by N-terminal acetyltransferases (NATs), is a conserved and primary modification of nascent peptide chains. Naa60 (also named NatF) is a recently identified NAT found only in multicellular eukaryotes. This protein was shown to locate on the Golgi apparatus and mainly catalyze the Nt-acetylation of transmembrane proteins, and it also harbors lysine Nε-acetyltransferase (KAT) activity to catalyze the acetylation of lysine ε-amine. Here, we report the crystal structures of human Naa60 (hNaa60) in complex with Acetyl-Coenzyme A (Ac-CoA) or Coenzyme A (CoA). The hNaa60 protein contains an amphipathic helix following its GNAT domain that may contribute to Golgi localization of hNaa60, and the β7-β8 hairpin adopted different conformations in the hNaa60(1-242) and hNaa60(1-199) crystal structures. Remarkably, we found that the side-chain of Phe 34 can influence the position of the coenzyme, indicating a new regulatory mechanism involving enzyme, co-factor and substrates interactions. Moreover, structural comparison and biochemical studies indicated that Tyr 97 and His 138 are key residues for catalytic reaction and that a non-conserved β3-β4 long loop participates in the regulation of hNaa60 activity. PMID:27550639

  4. Structure and function of human Naa60 (NatF), a Golgi-localized bi-functional acetyltransferase.

    PubMed

    Chen, Ji-Yun; Liu, Liang; Cao, Chun-Ling; Li, Mei-Jun; Tan, Kemin; Yang, Xiaohan; Yun, Cai-Hong

    2016-01-01

    N-terminal acetylation (Nt-acetylation), carried out by N-terminal acetyltransferases (NATs), is a conserved and primary modification of nascent peptide chains. Naa60 (also named NatF) is a recently identified NAT found only in multicellular eukaryotes. This protein was shown to locate on the Golgi apparatus and mainly catalyze the Nt-acetylation of transmembrane proteins, and it also harbors lysine N(ε)-acetyltransferase (KAT) activity to catalyze the acetylation of lysine ε-amine. Here, we report the crystal structures of human Naa60 (hNaa60) in complex with Acetyl-Coenzyme A (Ac-CoA) or Coenzyme A (CoA). The hNaa60 protein contains an amphipathic helix following its GNAT domain that may contribute to Golgi localization of hNaa60, and the β7-β8 hairpin adopted different conformations in the hNaa60(1-242) and hNaa60(1-199) crystal structures. Remarkably, we found that the side-chain of Phe 34 can influence the position of the coenzyme, indicating a new regulatory mechanism involving enzyme, co-factor and substrates interactions. Moreover, structural comparison and biochemical studies indicated that Tyr 97 and His 138 are key residues for catalytic reaction and that a non-conserved β3-β4 long loop participates in the regulation of hNaa60 activity. PMID:27550639

  5. Mutation of an Arabidopsis NatB N-Alpha-Terminal Acetylation Complex Component Causes Pleiotropic Developmental Defects

    PubMed Central

    Ferrández-Ayela, Almudena; Alonso-Peral, María Magdalena; Micol, José Luis; Ponce, María Rosa

    2013-01-01

    N-α-terminal acetylation is one of the most common, but least understood modifications of eukaryotic proteins. Although a high degree of conservation exists between the N-α-terminal acetylomes of plants and animals, very little information is available on this modification in plants. In yeast and humans, N-α-acetyltransferase complexes include a single catalytic subunit and one or two auxiliary subunits. Here, we report the positional cloning of TRANSCURVATA2 (TCU2), which encodes the auxiliary subunit of the NatB N-α-acetyltransferase complex in Arabidopsis. The phenotypes of loss-of-function tcu2 alleles indicate that NatB complex activity is required for flowering time regulation and for leaf, inflorescence, flower, fruit and embryonic development. In double mutants, tcu2 alleles synergistically interact with alleles of ARGONAUTE10, which encodes a component of the microRNA machinery. In summary, NatB-mediated N-α-terminal acetylation of proteins is pleiotropically required for Arabidopsis development and seems to be functionally related to the microRNA pathway. PMID:24244708

  6. Efficacy of ampicillin trihydrate or ceftiofur hydrochloride for treatment of metritis and subsequent fertility in dairy cows.

    PubMed

    Lima, F S; Vieira-Neto, A; Vasconcellos, G S F M; Mingoti, R D; Karakaya, E; Solé, E; Bisinotto, R S; Martinez, N; Risco, C A; Galvão, K N; Santos, J E P

    2014-09-01

    Our objectives were to evaluate the efficacy of ampicillin trihydrate for the treatment of metritis in dairy cows compared with ceftiofur hydrochloride and the subsequent effects on pregnancy at first insemination (P/AI). Cows in the first 12 d in milk (DIM) with a uterine discharge score of 5 (watery, reddish or brownish discharge of foul smell) and rectal temperature <39.5°C were diagnosed with metritis based on the fetid discharge, and cows with metritis and rectal temperature ≥39.5°C were diagnosed as having puerperal metritis. Cows with metritis (n=528) were blocked by parity and type of metritis as fetid discharge or puerperal metritis and, within each block, assigned randomly to receive 11mg/kg of ampicillin (n=259) or 2.2mg/kg of ceftiofur (n=269) once daily for 5 d. Day of diagnosis of metritis was considered study d 1. A cohort of 268 cows without metritis was selected randomly at 12 DIM. Rectal temperature was measured in cows with metritis on study d 1 to 7, and 12, and vaginal discharge was scored on study d 5, 7, and 12. Metritis cure was characterized by vaginal discharge score of <5 or by vaginal discharge score of <5 and no fever. At 32±3 DIM, vaginal discharge was scored for diagnosis of purulent vaginal discharge. At 39±3 DIM, endometrial cytology was performed. At 53±3 and 67±3 DIM, ovaries were scanned to determine estrous cyclicity. Pregnancy was evaluated after the first AI. Cure of metritis based on vaginal discharge <5 was greater for ampicillin than ceftiofur on d 5 (37.1 vs. 25.2%) and 7 (57.2 vs. 46.3%), but not on d 12 (82.0 vs. 85.0%). Cure of metritis based on vaginal discharge <5 and no fever was greater for ampicillin than for ceftiofur only on d 7 (50.4 vs. 37.9%), but not on d 5 (23.1 vs. 17.6%) and 12 (66.1 vs. 67.4%). Cows with puerperal metritis had reduced cure compared with cows with fetid discharge on d 5 (30.5 vs. 12.8%), 7 (55.2 vs. 33.6%), and 12 (72.0 vs. 61.1%). The proportion of cows with fever on any day after

  7. Alba from Thermoplasma volcanium belongs to α-NAT's: An insight into the structural aspects of Tv Alba and its acetylation by Tv Ard1.

    PubMed

    Ma, Chao; Pathak, Chinar; Lee, Sang Jae; Lee, Ki-Young; Jang, Sun-Bok; Nam, Minjoo; Im, Hookang; Yoon, Hye-Jin; Lee, Bong-Jin

    2016-01-15

    The Alba superfamily proteins have been regarded as a conserved group of proteins in archaea and eukarya, which have shown to be important in nucleic acid binding, chromatic organization and gene regulation. These proteins often belong to the N-acetyltransferase (NAT) category (N(α)-acetyltransferases or N(ε)-acetyltransferases) and undergo post-translational modifications. Here, we report the crystal structure of Alba from Thermoplasma volcanium (Tv Alba) at 2.4 Å resolution. The acetylation of Tv Alba was monitored and the N-terminal of Tv Alba has been shown to interact with acetyl coenzyme A (Ac-CoA). The chemical shift perturbation experiments of Tv Alba were performed in the presence of Ac-CoA and/or Tv Ard1, another T. volcanium protein that treats Tv Alba as a substrate. To examine the DNA binding capabilities of Tv Alba alone and in the presence of Ac-CoA and/or Tv Ard1, EMSA experiments were carried out. It is shown that although Tv Alba binds to Ac-CoA, the acetylation of Tv Alba is not related with its binding to dsDNA, and the involvement of the N-terminus in Ac-CoA binding demonstrates that Tv Alba belongs to the N(α)-acetyltransferase family. PMID:26657068

  8. Towards flash flood disaster prevention: the SciNetNat Haz proposal

    NASA Astrophysics Data System (ADS)

    Konstantinos, Papatheodorou; Elena, Tzanou; Carmen, Maftei; Ozgur, Kirca; Hafzullah, Aksoy

    2015-04-01

    Floods occur with a continuously increasing frequency due to climatic changes and cause serious damage in the wider Black Sea area, endangering human life and property. As societies continuously expand, these phenomena are expected to play an increasingly important role, blocking sustainable development unless properly tackled. Flash flood prevention seems at this point, to be the target of effectively mitigating the potential threat. Since in many cases, there is a cross-border character of the problem, collaborative efforts have to be made involving cooperation between countries. To this end, a variety of problems exist, including the "information gap" related to the unavailability of data and the multitude of methodologies used to assess flood hazard; a fact that renders comparison of hazard assessment results and cross border cooperation ineffective. An effort made within the context of the SciNetNatHaz project, suggests a two step approach to produce reliable the results which can lead to decision making regarding designing preventive measures. The first step aims at defining the flood prone areas on a regional scale, using geomorphometric models and readily available topographic data; thus overcoming the problem of data availability for any region of interest. The second step follows a vulnerability and risk assessment of the flood prone areas of interest and focuses on the calculation of flood parameters on a local scale using hydraulic models. Implementation of the full process is based on Open Source software tools so that it can be implemented with minimal costs by anyone interested. Implementation of the proposed procedure in three different cases in Greece and in Romania shows that it can provide accurate and reliable results to support decision making regarding the design of preventive measures. Keywords: Flash floods, hazard assessment, flood disaster prevention, HEC-RAS, SAGA GIS . Acknowledgements: This work is partially funded by the EU through the

  9. NAT1, NOS3, and TYMS Genotypes and the Risk of Conotruncal Cardiac Defects

    PubMed Central

    Lupo, Philip J.; Mitchell, Laura E.; Goldmuntz, Elizabeth

    2015-01-01

    Background Although congenital heart defects (CHDs) are a common and serious group of birth defects, relatively little is known about the causes of these conditions, and there are no established prevention strategies. There is, however, evidence suggesting that the risk of CHDs in general, and conotruncal and related defects (CTRDs) in particular, may be associated with maternal folate status and genetic variants of folate-related genes. Although several folate-related genes have been studied as they relate to CHDs and CTRDs (e.g., MTHFR), others have not been adequately assessed. Methods Case-parent triads were examined using log-linear analyses to assess the associations between CTRDs and both the genotype inherited by the case and the maternal genotype for the following variants: NAT1 1095C>A, NOS3 894G>T, and TYMS 1494del6. Subgroup analyses were also conducted among cases with classic conotruncal defects and cases with normally related great arteries. Results The results provided little evidence that CTRD risk was associated with the genotype inherited by the case for any of the analyzed variants. However, our results suggest that CTRD risk may be associated with the maternal genotype for NOS3 894G>T (p = 0.024 in the subgroup with normally related great arteries) and TYMS 1494del6 (p = 0.048 in the subgroup with classic conotruncal defects). However, these results were not significant after correcting for multiple comparisons. Conclusion This study provides further evidence that CTRD risk may be related to variation within folate-pathway genes and suggests that these associations are, at least in part, mediated through the maternal genotype. PMID:21254360

  10. Evaluation of polymorphisms in the sulfonamide detoxification genes NAT2, CYB5A, and CYB5R3 in patients with sulfonamide hypersensitivity

    PubMed Central

    Sacco, James; Abouraya, Mahmoud; Motsinger-Reif, Alison; Yale, Steven; McCarty, Catherine; Trepanier, Lauren

    2013-01-01

    Objective To determine whether polymorphisms in the sulfonamide detoxification genes, CYB5A (encoding cytochrome b5), CYB5R3 (encoding cytochrome b5 reductase), or NAT2 (encoding N-acetyltransferase 2) were over-represented in patients with delayed sulfonamide drug hypersensitivity, compared to control patients that tolerated a therapeutic course of trimethoprim-sulfamethoxazole without adverse event. Methods DNA from 99 non-immunocompromised patients with sulfonamide hypersensitivity that were identified from the Personalized Medicine Research Project at the Marshfield Clinic, and from 99 age-, race-, and gender-matched drug-tolerant controls, were genotyped for four CYB5A and five CYB5R3 polymorphisms, and for all coding NAT2 SNPs. Results CYB5A and CYB5R3 SNPs were found at low allele frequencies (less than 3–4%), which did not differ between hypersensitive and tolerant patients. NAT2 allele and haplotype frequencies, as well as inferred NAT2 phenotypes, also did not differ between groups (60% vs. 59% slow acetylators). Finally, no difference in NAT2 status was found in a subset of patients with more severe hypersensitivity signs (drug reaction with eosinophilia and systemic symptoms; DRESS) compared to tolerant patients. Conclusions We found no evidence for a substantial involvement of these 9 CYB5A or CYB5R3 polymorphisms in sulfonamide HS risk, although minor effects cannot be completely ruled out. Despite careful medical record review and full re-sequencing of the NAT2 coding region, we found no association of NAT2 coding alleles with sulfonamide hypersensitivity (predominantly cutaneous eruptions) in this adult Caucasian population. PMID:22850190

  11. NatF Contributes to an Evolutionary Shift in Protein N-Terminal Acetylation and Is Important for Normal Chromosome Segregation

    PubMed Central

    Helsens, Kenny; Vandekerckhove, Joël; Martinho, Rui G.; Gevaert, Kris; Arnesen, Thomas

    2011-01-01

    N-terminal acetylation (N-Ac) is a highly abundant eukaryotic protein modification. Proteomics revealed a significant increase in the occurrence of N-Ac from lower to higher eukaryotes, but evidence explaining the underlying molecular mechanism(s) is currently lacking. We first analysed protein N-termini and their acetylation degrees, suggesting that evolution of substrates is not a major cause for the evolutionary shift in N-Ac. Further, we investigated the presence of putative N-terminal acetyltransferases (NATs) in higher eukaryotes. The purified recombinant human and Drosophila homologues of a novel NAT candidate was subjected to in vitro peptide library acetylation assays. This provided evidence for its NAT activity targeting Met-Lys- and other Met-starting protein N-termini, and the enzyme was termed Naa60p and its activity NatF. Its in vivo activity was investigated by ectopically expressing human Naa60p in yeast followed by N-terminal COFRADIC analyses. hNaa60p acetylated distinct Met-starting yeast protein N-termini and increased general acetylation levels, thereby altering yeast in vivo acetylation patterns towards those of higher eukaryotes. Further, its activity in human cells was verified by overexpression and knockdown of hNAA60 followed by N-terminal COFRADIC. NatF's cellular impact was demonstrated in Drosophila cells where NAA60 knockdown induced chromosomal segregation defects. In summary, our study revealed a novel major protein modifier contributing to the evolution of N-Ac, redundancy among NATs, and an essential regulator of normal chromosome segregation. With the characterization of NatF, the co-translational N-Ac machinery appears complete since all the major substrate groups in eukaryotes are accounted for. PMID:21750686

  12. N-acetyltransferase 2 (NAT2) gene polymorphism as a predisposing factor for phenytoin intoxication in tuberculous meningitis or tuberculoma patients having seizures - A pilot study

    PubMed Central

    Adole, Prashant S.; Kharbanda, Parampreet S.; Sharma, Sadhna

    2016-01-01

    Background & objectives: Simultaneous administration of phenytoin and isoniazid (INH) in tuberculous meningitis (TBM) or tuberculoma patients with seizures results in higher plasma phenytoin level and thus phenytoin intoxication. N-acetyltransferase 2 (NAT2) enzyme catalyses two acetylation reactions in INH metabolism and NAT2 gene polymorphism leads to slow and rapid acetylators. The present study was aimed to evaluate the effect of allelic variants of N-acetyltransferase 2 (NAT2) gene as a predisposing factor for phenytoin toxicity in patients with TBM or tuberculoma having seizures, and taking INH and phenytoin simultaneously. Methods: Sixty patients with TBM or tuberculoma with seizures and taking INH and phenytoin simultaneously for a minimum period of seven days were included in study. Plasma phenytoin was measured by high performance liquid chromatography. NAT2 gene polymorphism was studied using restriction fragment length polymorphism and allele specific PCR. Results: The patients were grouped into those having phenytoin intoxication and those with normal phenytoin level, and also classified as rapid or slow acetylators by NAT2 genotyping. Genotypic analysis showed that of the seven SNPs (single nucleotide polymorphisms) of NAT2 gene studied, six mutations were found to be associated with phenytoin intoxication. For rs1041983 (C282T), rs1799929 (C481T), rs1799931 (G857A), rs1799930 (G590A), rs1208 (A803G) and rs1801280 (T341C) allelic variants, the proportion of homozygous mutant was higher in phenytoin intoxicated group than in phenytoin non-intoxicated group. Interpretation & conclusions: Homozygous mutant allele of NAT2 gene at 481site may act as a predisposing factor for phenytoin intoxication among TBM or tuberculoma patients having seizures. PMID:27488001

  13. Talc use, variants of the GSTM1, GSTT1, and NAT2 genes, and risk of epithelial ovarian cancer.

    PubMed

    Gates, Margaret A; Tworoger, Shelley S; Terry, Kathryn L; Titus-Ernstoff, Linda; Rosner, Bernard; De Vivo, Immaculata; Cramer, Daniel W; Hankinson, Susan E

    2008-09-01

    Epidemiologic evidence suggests a possible association between genital use of talcum powder and risk of epithelial ovarian cancer; however, the biological basis for this association is not clear. We analyzed interactions between talc use and genes in detoxification pathways [glutathione S-transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), and N-acetyltransferase 2 (NAT2)] to assess whether the talc/ovarian cancer association is modified by variants of genes potentially involved in the response to talc. Our analysis included 1,175 cases and 1,202 controls from a New England-based case-control study and 210 cases and 600 controls from the prospective Nurses' Health Study. We genotyped participants for the GSTM1 and GSTT1 gene deletions and three NAT2 polymorphisms. We used logistic regression to analyze the main effect of talc use, genotype, and gene-talc interactions in each population and pooled the estimates using a random-effects model. Regular talc use was associated with increased ovarian cancer risk in the combined study population (RR, 1.36; 95% CI, 1.14-1.63; P(trend) < 0.001). Independent of talc, the genes examined were not clearly associated with risk. However, the talc/ovarian cancer association varied by GSTT1 genotype and combined GSTM1/GSTT1 genotype. In the pooled analysis, the association with talc was stronger among women with the GSTT1-null genotype (P(interaction) = 0.03), particularly in combination with the GSTM1-present genotype (P(interaction) = 0.03). There was no clear evidence of an interaction with GSTM1 alone or NAT2. These results suggest that women with certain genetic variants may have a higher risk of ovarian cancer associated with genital talc use. Additional research is needed on these interactions and the underlying biological mechanisms. PMID:18768514

  14. Characterization of ARGON-40 + Silver-Nat Reactions: Timescales and Emission Orders

    NASA Astrophysics Data System (ADS)

    Gelderloos, Carl James

    Studies have been made of ejectile coincidences resulting from ^{40}Ar + ^{nat}Ag reactions at bombarding energies of 17A-34A MeV. Correlations at both large and small relative angles are used to characterize the emission of light charged particles and fragments on a timescale of ~10^ {-22} s. Average delay times and emission orders between ejectiles are inferred by comparison to simulation calculations. Correlation functions in relative momentum, and spectra of the velocity differences between ejectiles emitted at small relative angles have been used to infer reaction dynamics. Trajectories of ejectile coincidences are particularly sensitive to the initial spatial and temporal relationship between the ejectiles and source. As the excitation energy of the emitter increases, the time delays between emissions decrease. The excitation energy deposited in central collisions increases from ~3 MeV per emitter nucleon at 17A MeV to nearly 6A MeV at 34A MeV. The measured delay times between ejectiles decrease steadily over this range. A simulation was developed to probe the degree of equilibration that is achieved by the composite nuclear system. It consists of a statistical model description of the emission of particles and a trajectory model calculation of the three-body interactions. Empirical lifetimes are substantially shorter than those predicted by model calculations, suggesting a regime in which partial, but not complete, equilibration is achieved. A novel method is also developed for measuring the average emission order for different ejectile pairs. The interactions between ejectiles differentiate between coincident events with different velocity relationships. At small relative angles these interactions are sufficiently strong to preferentially select events of a particular emission order. This method provides a new experimental observable with which to further constrain model descriptions. It is implemented to test for differences in average emission order

  15. Multiple Conformations of the Loop Region Confers Heat-Resistance on SsArd1, a Thermophilic NatA.

    PubMed

    Chang, Yu-Yung; Hsu, Chun-Hua

    2016-02-01

    Structural comparison indicates that the loop region between β3 and β4 of SsArd1 is extended relative to the corresponding region in mesophilic Nats, and forms a plastic hydrogen-bond network mainly at two serine residues. Strikingly, two single-point mutants showed ∼3 °C decrease in melting temperature, and two other variants showed ∼7 °C decrease; this correlated with significantly reduced enzymatic activity. To our knowledge, this is the first discovery of a loop region capable of remarkably improving protein thermostability. This provides a novel route to engineer heat-resistant proteins. PMID:26593285

  16. Excitation functions for production of 46Sc by deuteron and proton beams in natTi: A basis for additional monitor reactions

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Tárkányi, F.; Takács, S.; Ditrói, F.; Amjed, N.

    2014-11-01

    An objective of a new Coordinated Research Program launched recently by IAEA is to strengthen and broaden the cross section database for monitoring of charged particle beams given in IAEA-TECDOC-1211. One of the suggestions is to complement the widely used natTi(d,x)48V monitor reaction by the natTi(d,x)46Sc reaction having a maximum in a somewhat higher energy. After compilation of the data sets for this reaction available in literature and unpublished data from our earlier experiments, a selection of 20 sets is proposed for statistical fitting and extraction of recommended values. A similar analysis is presented for the natTi(p,x)46Sc reaction where 16 datasets are finally selected.

  17. Decreased DNA Methylation in the Shati/Nat8l Promoter in Both Patients with Schizophrenia and a Methamphetamine-Induced Murine Model of Schizophrenia-Like Phenotype

    PubMed Central

    Uno, Kyosuke; Kikuchi, Yuu; Iwata, Mina; Uehara, Takashi; Matsuoka, Tadasu; Sumiyoshi, Tomiki; Okamoto, Yoshinori; Jinno, Hideto; Takada, Tatsuyuki; Furukawa-Hibi, Yoko; Nabeshima, Toshitaka; Miyamoto, Yoshiaki

    2016-01-01

    The number of patients with schizophrenia has increased over the past decade. Previously, many studies have been performed to establish its diagnostic criteria, prophylactic methods, and effective therapies. In this study, we analyzed whether the ratios of DNA methylation in CpG islands of the Shati/Nat8l is decreased in model mice of schizophrenia-like phenotype using genomic DNA collected from brain regions and peripheral blood, since the mouse model of schizophrenia-like phenotype, mice treated repeatedly with methamphetamine showed increase of Shati/Nat8l mRNA expression in our previous experiment. The ratios of Shati/Nat8l CpG island methylation were significantly decreased in both the nucleus accumbens and the peripheral blood of model mice compared with those of control mice. We also investigated Shati/Nat8l methylation in the blood of patients with schizophrenia. We found that Shati/Nat8l CpG island methylation ratios were lower in the patients with schizophrenia than in the healthy controls, which is consistent with our findings in the mice model. To our knowledge, this is the first study to show similar alterations in methylation status of a particular genomic DNA site in both the brain and peripheral blood of mice. Furthermore, the same phenomenon was observed in corresponding human genomic sequences of the DNA extracted from the peripheral blood of patients with schizophrenia. Based on our findings, DNA methylation profiles of the CpG island of Shati/Nat8l might be a diagnostic biomarker of schizophrenia. PMID:27348532

  18. Decreased DNA Methylation in the Shati/Nat8l Promoter in Both Patients with Schizophrenia and a Methamphetamine-Induced Murine Model of Schizophrenia-Like Phenotype.

    PubMed

    Uno, Kyosuke; Kikuchi, Yuu; Iwata, Mina; Uehara, Takashi; Matsuoka, Tadasu; Sumiyoshi, Tomiki; Okamoto, Yoshinori; Jinno, Hideto; Takada, Tatsuyuki; Furukawa-Hibi, Yoko; Nabeshima, Toshitaka; Miyamoto, Yoshiaki; Nitta, Atsumi

    2016-01-01

    The number of patients with schizophrenia has increased over the past decade. Previously, many studies have been performed to establish its diagnostic criteria, prophylactic methods, and effective therapies. In this study, we analyzed whether the ratios of DNA methylation in CpG islands of the Shati/Nat8l is decreased in model mice of schizophrenia-like phenotype using genomic DNA collected from brain regions and peripheral blood, since the mouse model of schizophrenia-like phenotype, mice treated repeatedly with methamphetamine showed increase of Shati/Nat8l mRNA expression in our previous experiment. The ratios of Shati/Nat8l CpG island methylation were significantly decreased in both the nucleus accumbens and the peripheral blood of model mice compared with those of control mice. We also investigated Shati/Nat8l methylation in the blood of patients with schizophrenia. We found that Shati/Nat8l CpG island methylation ratios were lower in the patients with schizophrenia than in the healthy controls, which is consistent with our findings in the mice model. To our knowledge, this is the first study to show similar alterations in methylation status of a particular genomic DNA site in both the brain and peripheral blood of mice. Furthermore, the same phenomenon was observed in corresponding human genomic sequences of the DNA extracted from the peripheral blood of patients with schizophrenia. Based on our findings, DNA methylation profiles of the CpG island of Shati/Nat8l might be a diagnostic biomarker of schizophrenia. PMID:27348532

  19. Integrated sample-to-detection chip for nucleic acid test assays.

    PubMed

    Prakash, R; Pabbaraju, K; Wong, S; Tellier, R; Kaler, K V I S

    2016-06-01

    Nucleic acid based diagnostic techniques are routinely used for the detection of infectious agents. Most of these assays rely on nucleic acid extraction platforms for the extraction and purification of nucleic acids and a separate real-time PCR platform for quantitative nucleic acid amplification tests (NATs). Several microfluidic lab on chip (LOC) technologies have been developed, where mechanical and chemical methods are used for the extraction and purification of nucleic acids. Microfluidic technologies have also been effectively utilized for chip based real-time PCR assays. However, there are few examples of microfluidic systems which have successfully integrated these two key processes. In this study, we have implemented an electro-actuation based LOC micro-device that leverages multi-frequency actuation of samples and reagents droplets for chip based nucleic acid extraction and real-time, reverse transcription (RT) PCR (qRT-PCR) amplification from clinical samples. Our prototype micro-device combines chemical lysis with electric field assisted isolation of nucleic acid in a four channel parallel processing scheme. Furthermore, a four channel parallel qRT-PCR amplification and detection assay is integrated to deliver the sample-to-detection NAT chip. The NAT chip combines dielectrophoresis and electrostatic/electrowetting actuation methods with resistive micro-heaters and temperature sensors to perform chip based integrated NATs. The two chip modules have been validated using different panels of clinical samples and their performance compared with standard platforms. This study has established that our integrated NAT chip system has a sensitivity and specificity comparable to that of the standard platforms while providing up to 10 fold reduction in sample/reagent volumes. PMID:27165104

  20. New strategies for blood donor screening for hepatitis B virus: nucleic acid testing versus immunoassay methods.

    PubMed

    Kuhns, Mary C; Busch, Michael P

    2006-01-01

    Serologic testing for hepatitis B virus (HBV) surface antigen (HBsAg) and antibody to HBV core antigen (anti-HBc) has historically been the foundation of blood screening, while HBV nucleic acid testing (NAT) was recently developed to detect HBsAg-negative, anti-HBc-negative blood units donated during early acute infection. Comparison data on seroconversion panels using HBsAg assays of varying sensitivities and pooled- or single-sample NAT, along with viral load estimates corresponding to HBsAg assay detection limits, have provided information on the theoretical benefits of NAT relative to HBsAg. Model-derived estimates have generally been predictive of the yields of DNA-positive, HBsAg-negative window period blood units detected in a number of studies from Europe, Japan, and the US. Studies indicate that the added benefit of pooled-sample NAT is relatively small in areas of low endemicity, with greater yields in areas highly endemic for HBV. Single-sample NAT would offer more significant early window period closure and could prevent a moderate number of residual HBV transmissions not detected by HBsAg assays; however, no fully automated single-sample HBV NAT systems are currently available.Even single-sample HBV NAT may not substitute for anti-HBc screening, as indicated by studies of donors with isolated anti-HBc who have extremely low DNA levels undetectable by standard single-sample NAT and who have been associated with transfusion-transmitted HBV. Moreover, HBsAg testing may still be needed even in the setting of combined anti-HBc and NAT screening. HBsAg-positive units from donors in the chronic stage of infection may contain very low or intermittently detectable DNA levels that single-sample NAT would miss. Although such donors are usually anti-HBc reactive and would be interdicted by anti-HBc screening, some lack anti-HBc. Extensive parallel testing will be needed to determine whether single-sample NAT in combination with anti-HBc might be sufficient to

  1. Standing of nucleic acid testing strategies in veterinary diagnosis laboratories to uncover Mycobacterium tuberculosis complex members

    PubMed Central

    Costa, Pedro; Botelho, Ana; Couto, Isabel; Viveiros, Miguel; Inácio, João

    2014-01-01

    Nucleic acid testing (NAT) designate any molecular approach used for the detection, identification, and characterization of pathogenic microorganisms, enabling the rapid, specific, and sensitive diagnostic of infectious diseases, such as tuberculosis. These assays have been widely used since the 90s of the last century in human clinical laboratories and, subsequently, also in veterinary diagnostics. Most NAT strategies are based in the polymerase chain reaction (PCR) and its several enhancements and variations. From the conventional PCR, real-time PCR and its combinations, isothermal DNA amplification, to the nanotechnologies, here we review how the NAT assays have been applied to decipher if and which member of the Mycobacterium tuberculosis complex is present in a clinical sample. Recent advances in DNA sequencing also brought new challenges and have made possible to generate rapidly and at a low cost, large amounts of sequence data. This revolution with the high-throughput sequencing (HTS) technologies makes whole genome sequencing (WGS) and metagenomics the trendiest NAT strategies, today. The ranking of NAT techniques in the field of clinical diagnostics is rising, and we provide a SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis with our view of the use of molecular diagnostics for detecting tuberculosis in veterinary laboratories, notwithstanding the gold standard being still the classical culture of the agent. The complementary use of both classical and molecular diagnostics approaches is recommended to speed the diagnostic, enabling a fast decision by competent authorities and rapid tackling of the disease. PMID:25988157

  2. Standing of nucleic acid testing strategies in veterinary diagnosis laboratories to uncover Mycobacterium tuberculosis complex members.

    PubMed

    Costa, Pedro; Botelho, Ana; Couto, Isabel; Viveiros, Miguel; Inácio, João

    2014-01-01

    Nucleic acid testing (NAT) designate any molecular approach used for the detection, identification, and characterization of pathogenic microorganisms, enabling the rapid, specific, and sensitive diagnostic of infectious diseases, such as tuberculosis. These assays have been widely used since the 90s of the last century in human clinical laboratories and, subsequently, also in veterinary diagnostics. Most NAT strategies are based in the polymerase chain reaction (PCR) and its several enhancements and variations. From the conventional PCR, real-time PCR and its combinations, isothermal DNA amplification, to the nanotechnologies, here we review how the NAT assays have been applied to decipher if and which member of the Mycobacterium tuberculosis complex is present in a clinical sample. Recent advances in DNA sequencing also brought new challenges and have made possible to generate rapidly and at a low cost, large amounts of sequence data. This revolution with the high-throughput sequencing (HTS) technologies makes whole genome sequencing (WGS) and metagenomics the trendiest NAT strategies, today. The ranking of NAT techniques in the field of clinical diagnostics is rising, and we provide a SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis with our view of the use of molecular diagnostics for detecting tuberculosis in veterinary laboratories, notwithstanding the gold standard being still the classical culture of the agent. The complementary use of both classical and molecular diagnostics approaches is recommended to speed the diagnostic, enabling a fast decision by competent authorities and rapid tackling of the disease. PMID:25988157

  3. Excitation functions of (nat)Zn(p,x) nuclear reactions with proton beam energy below 18 MeV.

    PubMed

    Asad, Ali H; Chan, Sun; Morandeau, Laurence; Cryer, David; Smith, Suzanne V; Price, Roger I

    2014-12-01

    We measured the excitation functions of (nat)Zn (p,x) reactions up to 17.6MeV, using the stacked-foils activation technique. High-purity natural zinc (and copper) foils were irradiated with proton beams generated by an 18MeV isochronous cyclotron. Activated foils were measured using high-purity Ge gamma spectroscopy to quantify the radionuclides (61)Cu, (66)Ga, (67)Ga, and (65)Zn produced from the reactions. Thick-target integral yields were also deduced from the measured excitation functions of the produced radioisotopes. These results were compared with the published literature and were found to be in good agreement with most reports, particularly those most recently compiled. PMID:25108597

  4. Measurement and theoretical analysis of the excitation functions for 3He induced reactions on natSn

    NASA Astrophysics Data System (ADS)

    Ali, B. M.; Al-Abyad, M.; Seddik, U.; El-Kameesy, S. U.; Ditrói, F.; Takács, S.; Tárkányi, F.

    2015-11-01

    Excitation functions of 3He induced nuclear reactions on natSn were measured up to 26 MeV using the stacked-foil technique, utilizing the MGC-20E cyclotron of ATOMKI. Using HPGe detector the following radioisotopes were identified: 116,117,118,119g,119m,121g,121m,123mTe, 115g,116m,117,118m,120m,122g,124gSb and 113g,117mSn. The experimental results are presented for the first time in this energy range. The results of theoretical calculations based on EMPIRE and TENDL library were compared with the present data. Integral yields for some isotopes were calculated.

  5. Comparative genomic survey, exon-intron annotation and phylogenetic analysis of NAT-homologous sequences in archaea, protists, fungi, viruses, and invertebrates

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have previously published extensive genomic surveys [1-3], reporting NAT-homologous sequences in hundreds of sequenced bacterial, fungal and vertebrate genomes. We present here the results of our latest search of 2445 genomes, representing 1532 (70 archaeal, 1210 bacterial, 43 protist, 97 fungal,...

  6. The Hamburg Selection Procedure for Dental Students – Introduction of the HAM-Nat as subject-specific test for study aptitude

    PubMed Central

    Kothe, Christian; Hissbach, Johanna; Hampe, Wolfgang

    2013-01-01

    Introduction: The present study examines the question whether the selection of dental students should be based solely on average school-leaving grades (GPA) or whether it could be improved by using a subject-specific aptitude test. Methods: The HAM-Nat Natural Sciences Test was piloted with freshmen during their first study week in 2006 and 2007. In 2009 and 2010 it was used in the dental student selection process. The sample size in the regression models varies between 32 and 55 students. Results: Used as a supplement to the German GPA, the HAM-Nat test explained up to 12% of the variance in preclinical examination performance. We confirmed the prognostic validity of GPA reported in earlier studies in some, but not all of the individual preclinical examination results. Conclusion: The HAM-Nat test is a reliable selection tool for dental students. Use of the HAM-Nat yielded a significant improvement in prediction of preclinical academic success in dentistry. PMID:24282449

  7. A new parameterization of polar stratospheric clouds based on the effective growth of NAT particles in the chemistry-climate-model EMAC

    NASA Astrophysics Data System (ADS)

    Kirner, Ole; Ruhnke, Roland; Hoepfner, Michael

    2013-04-01

    Polar stratospheric clouds (PSCs), consisting of STS, NAT and ice particles, play a major role in polar ozone depletion. On the one hand there is the activation of chlorine reservoirs at the surface of the PSCs, on the other hand PSCs lead to the stratospheric denitrification with the effect of a delay in the deactivation of active chlorine in polar spring. Due to the relevance of a good representation of these PSCs in global chemistry-climate-models (CCMs) a new algorithm based on efficient growth of NAT particles, developed by van den Broek et al. [2004], has been implemented into the submodel PSC of the CCM ECHAM5/MESSy for Atmospheric Chemistry (EMAC). We present results of an EMAC simulation from 2000 to 2012, performed with the new NAT parameterization. The simulated results are analyzed regarding the composition of PSCs and their distribution in the polar regions as well as their influence to the ozone related chemistry. The new results are compared with an EMAC simulation with the old standard thermodynamical NAT parameterization. A comparison with PSC measurements retrieved by the satellite instrument MIPAS on ENVISAT [Höpfner et al., 2006] show the quality of the new PSC scheme in EMAC. With the help of an additional sensitivity simulation it can be shown that the significance of heterogeneous reactions on ice particles, in comparison to liquid particles, is subordinate regarding chlorine activation and ozone depletion in Antarctic winter and spring as noted in Drdla and Mueller [2012].

  8. Structural and spectroscopic characterization of 1-(diaminomethylene) thiouron-1-ium benzoate and bis(1-(diaminomethylene)thiouron-1-ium) phthalate trihydrate

    NASA Astrophysics Data System (ADS)

    Perpétuo, Genivaldo Julio; Janczak, Jan

    2016-02-01

    Two single crystals of 1-(diaminomethylene) thiouron-1-ium benzoate (1) and bis(1-(diaminomethylene)thiouron-1-ium) phthalate trihydrate (2) were grown using a solution growth technique. The compound 1 crystallises in the centrosymmetric P21/c space group of the monoclinic system, whereas the compound 2 in the centrosymmetric Pbcn space group of orthorhombic system. The solid-state organisation of 1 and 2 has been analysed with respect to cation-anion and hydrogen bonding interactions. The oppositely charged units interact via almost linear hydrogen bonds with the graphs of R22(8) and R21(6) forming molecular complexes. In the crystal 1 the R22(8) motif is formed by donation to the carboxylate group from amine group joined to C1 and from imine group and R21(6) motif is formed by donation to the O2 from amine group joined to C2 and from imine group, whereas in crystal 2 the graphs are formed oppositely. Interactions between the hydrogen-bonded molecular complexes in 1 lead to formation of layered 2D structure, whereas in 2, due to presence of hydrated water molecules lead to formation of 3D hydrogen-bonded supramolecular network. The obtained deuterated analogues of 1 and 2 crystallise similar as H-compound in the monoclinic and orthorhombic system with quite similar lattice parameters. The compounds were also characterised by the FT-IR and Raman spectroscopies. The characteristic bands of the functional and skeletal groups are discussed.

  9. The Impact of NAT2 Acetylator Genotype on Mutagenesis and DNA Adducts from 2-Amino-9H-Pyrido[2,3-b]Indole

    PubMed Central

    Turesky, Robert J.; Bendaly, Jean; Yasa, Isil; Doll, Mark A.; Hein, David W.

    2009-01-01

    2-Amino-9H-pyrido[2,3-b]indole (AαC) is a carcinogenic heterocyclic aromatic amine (HAA) that is produced in high quantities in tobacco smoke, and also forms in charred meats. The bioactivation of AαC occurs by cytochrome P450-mediated (P450 1A2) N-oxidation of the exocyclic amine group, to form 2-hydroxyamino-9H-pyrido[2,3-b]indole (HONH-AαC). The HONH-AαC metabolite can then undergo further activation by phase II enzymes to form the penultimate ester species, which bind to DNA. Some epidemiological studies suggest a role for NAT2 genetic polymorphisms in human susceptibilities to various cancers from tobacco smoke and from consumption of well-done meats, where the exposures to AαC can be substantial. In this investigation, we have measured the genotoxicity of AαC in nucleotide excision repair-deficient Chinese hamster ovary (CHO) cells stably transfected with human P450 1A2 and either the NAT2*4 (rapid, wild-type acetylator) or the NAT2*5B (the most common slow acetylator) allele, to determine the role of NAT2 phenotype in the biological effects of AαC. Mutations at the hypoxanthine phosphoribosyl transferase (hprt) locus were induced in a dose-dependent manner by AαC, and were found to be highest in cells transfected with P450 1A2 and NAT2*4, followed by cells transfected with P450 1A2 and NAT2*5B. The level of formation of the deoxyguanosine (dG) adduct N-(deoxyguanosin-8-yl)-2-amino-9H-pyrido[2,3-b]indole (dG-C8-AαC) paralleled the mutagenic potency, in these cell lines. However, AαC did not form DNA adducts or induce mutations in untransfected CHO cells, or in cells only expressing P450 1A2. These findings clearly demonstrate that NAT2 genetic polymorphism plays a major role in the genotoxic potency of AαC. PMID:19243127

  10. Excitation functions of the natTa(p,x)178m2Hf and natW(p,x)178m2Hf reactions at energies up to 2600 MeV

    SciTech Connect

    Titarenko, Yu. E.; Batyaev, V. F.; Pavlov, K. V.; Titarenko, A. Yu.; Zhivun, V. M.; Chauzova, M. V.; Ignatyuk, A. V.; Mashnik, Stepan Georgievich; Leray, S.; Boudard, A.; David, J. -C.; Mancusi, D.; Cugnon, J.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Stankovskiy, A. Yu.

    2015-04-29

    Due to potential level of energy intensity 178m2Hf is an extremely interesting isomer. One possible way to produce this isomer is irradiation of natTa or natW samples with high energy protons. Irradiation of natTa or natW samples performed for other purposes provides an opportunity to study the corresponding reactions. This paper presents the 178m2Hf independent production cross sections for both targets measured by the gamma-ray spectrometry method. The reaction excitation functions have been obtained for the proton energies from 40 up to 2600 MeV. The experimental results were compared with calculations by various versions of the intranuclear cascade model in the well-known codes: ISABEL, Bertini, INCL4.5+ABLA07, PHITS, CASCADE07 and CEM03.02. The isomer ratio for the natTa(p,x) 178m2Hf reaction is evaluated on the basis of the available data.

  11. The ultra-slow NAT2*6A haplotype is associated with reduced higher cognitive functions in an elderly study group.

    PubMed

    Selinski, Silvia; Getzmann, Stephan; Gajewski, Patrick D; Blaszkewicz, Meinolf; Hengstler, Jan G; Falkenstein, Michael; Golka, Klaus

    2015-12-01

    N-Acetyltransferase 2 (NAT2) genotype is associated with age-related declines in basic sensory hearing functions. However, the possible modulatory role of NAT2 for higher cognitive functions has not yet been studied. We tested auditory goal-directed behavior and attentional control in 120 NAT2 genotyped subjects (63-88 years), using an auditory distraction paradigm in which participants responded to the duration of long and short tone stimuli. We studied involuntary shifts in attention to task-irrelevant deviant stimuli and applied event-related potentials (ERPs) to examine which cognitive subprocesses are affected by NAT2 status on a neurophysiological level. Relative to the standard stimuli, deviant stimuli decreased performance in the recently described ultra-slow acetylators (NAT2*6A and *7B): The increase in error-corrected reaction times (a combined measure of response speed and accuracy) in ultra-slow acetylators (254 ms increase) was more than twice as high as in the rapid acetylator reference group (111 ms increase; p < 0.01). The increase was still higher than in the other slow acetylators (149 ms increase, p < 0.05). In addition, clear differences were found in the ERP results: Ultra-slow acetylators showed deficits specifically in the automatic detection of changes in the acoustic environment as evidenced by reduced mismatch negativity (MMN, p < 0.005 compared to rapid acetylators). Refocussing of attention after a distracting event was also impaired in the ultra-slow acetylators as evidenced by a reduced re-orienting negativity (RON, p < 0.01 compared to rapid acetylators). In conclusion, the ultra-slow acetylation status was associated with reduced higher cognitive functions. PMID:26615528

  12. Spectroscopic studies of model polar stratospheric cloud films

    NASA Technical Reports Server (NTRS)

    Tolbert, Margaret A.; Koehler, Birgit G.; Middlebrook, Ann M.

    1993-01-01

    Fourier transform infrared (FTIR) spectroscopy has been used to study nitric-acid/ice films representative of type I polar stratospheric clouds (PSCs). These studies reveal that in addition to amorphous nitric acid/ice mixtures, there are three stable stoichiometric hydrates of nitric acid: nitric-acid monohydrate (NAM), dihydrate (NAD), and trihydrate (NAT). We also observe two distinct crystalline forms of the trihydrate, which we denote alpha- and beta-NAT. These two forms appear to differ in their concentration of crystalline defects, but not in their chemical composition. In addition to probing the composition of type I PSCs, we have also used FTIR spectroscopy to study the interaction of HCl with model PSC films. In this work we find that for HCl pressures in the range 10 exp -5 to 10 exp -7 Torr, HCl is taken up by ice at 155 K to form a thin layer of HCl.6H2O. At 193 K, the uptake of HCl by ice was consistent with less than or equal to monolayer coverage. Uptake of HCl by alpha and beta-NAT at 175 K was also consistent with less than or equal to monolayer coverage.

  13. Microphysical Simulation of Polar Stratospheric Clouds Within the Community Earth System Model

    NASA Astrophysics Data System (ADS)

    Zhu, Yunqian

    Polar stratospheric clouds (PSCs) are critical elements for polar ozone depletion. A new PSC model coupling stratospheric chemistry, microphysics and climate is constructed and the formation of STS (Super-cooled Ternary Solution) and NAT (Nitric-Acid Trihydrate) PSCs are explored. STS particle properties are dominated by thermodynamics. Simulations of particle volumes and size distributions are generally within the observational error bars. STS particles are not in equilibrium with their environment when the particle surface area is smaller than 4 mum2/cm 3. A new nucleation rate equation for NAT is derived based on observed denitrification in the 2010-2011 Arctic winter. The homogeneous nucleation scheme leads to supermicron NAT particles as observed. The simulated the lidar backscatter, and denitrification are generally within observational error bars. However, the simulations are very sensitive to temperature. Using the same STS and NAT schemes, as well as a prognostic treatment for ice PSC formation and dehydration, the PSCs are simulated during the Antarctic winter of 2010. The current model correctly simulates large NAT particles and denitrification, but cannot produce NAT with high backscattering ratio/number density sometimes observed by CALIPSO. However, our simulated ice has similar backscatter and depolarization which is often attributed to NAT by CALIPSO. Possibly the CALIPSO algorithm misclassifies ice as NAT when the stratosphere is denitrified or dehydrated. STS and NAT form near the pole in May and June, but form a ring outside 80?S later in the winter when polar HNO3 is depleted. Ice always forms in the coldest area, but becomes less abundant later in the winter. The model is missing some processes forming NAT such as gravity waves or evaporating ice. These processes should be added to the model in the future.

  14. Overexpression of Shati/Nat8l, an N-acetyltransferase, in the nucleus accumbens attenuates the response to methamphetamine via activation of group II mGluRs in mice.

    PubMed

    Miyamoto, Yoshiaki; Ishikawa, Yudai; Iegaki, Noriyuki; Sumi, Kazuyuki; Fu, Kequan; Sato, Keiji; Furukawa-Hibi, Yoko; Muramatsu, Shin-Ichi; Nabeshima, Toshitaka; Uno, Kyosuke; Nitta, Atsumi

    2014-08-01

    A novel N-acetyltransferase, Shati/Nat8l, was identified in the nucleus accumbens (NAc) of mice with methamphetamine (METH) treatment. Previously we reported that suppression of Shati/Nat8l enhanced METH-induced behavioral alterations via dopaminergic neuronal regulation. However, the physiological mechanisms of Shati/Nat8l on the dopaminergic system in the brain are unclear. In this study, we injected adeno-associated virus (AAV) vector containing Shati/Nat8l into the NAc or dorsal striatum (dS) of mice, to increase Shati/Nat8l expression. Overexpression of Shati/Nat8l in the NAc, but not in the dS, attenuated METH-induced hyperlocomotion, locomotor sensitization, and conditioned place preference in mice. Moreover, the Shati/Nat8l overexpression in the NAc attenuated the elevation of extracellular dopamine levels induced by METH in in vivo microdialysis experiments. These behavioral and neurochemical alterations due to Shati/Nat8l overexpression in the NAc were inhibited by treatment with selective group II metabotropic glutamate receptor type 2 and 3 (mGluR2/3) antagonist LY341495. In the AAV vector-injected NAc, the tissue contents of both N-acetylaspartate and N-acetylaspartylglutamate (NAAG), endogenous mGluR3 agonist, were elevated. The injection of peptidase inhibitor of NAAG or the perfusion of NAAG itself reduced the basal levels of extracellular dopamine in the NAc of naive mice. These results indicate that Shati/Nat8l in the NAc, but not in the dS, plays an important suppressive role in the behavioral responses to METH by controlling the dopaminergic system via activation of group II mGluRs. PMID:24559655

  15. Excitation functions of the natCr(p,x)44Ti, 56Fe(p,x)44Ti, natNi(p,x)44Ti and 93Nb(p,x)44Ti reactions at energies up to 2.6 GeV

    NASA Astrophysics Data System (ADS)

    Titarenko, Yu. E.; Batyaev, V. F.; Pavlov, K. V.; Titarenko, A. Yu.; Zhivun, V. M.; Chauzova, M. V.; Balyuk, S. A.; Bebenin, P. V.; Ignatyuk, A. V.; Mashnik, S. G.; Leray, S.; Boudard, A.; David, J. C.; Mancusi, D.; Cugnon, J.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Stankovskiy, A. Yu.

    2016-06-01

    The paper presents the measured cumulative yields of 44Ti for natCr, 56Fe, natNi and 93Nb samples irradiated by protons at the energy range 0.04-2.6 GeV. The obtained excitation functions are compared with calculations of the well-known codes: ISABEL, Bertini, INCL4.2+ABLA, INCL4.5+ABLA07, PHITS, CASCADE07 and CEM03.02. The predictive power of these codes regarding the studied nuclides is analyzed.

  16. Polar stratospheric clouds observed at Eureka (80°N, 86°W) in the Canadian Arctic during the 1994/1995 winter

    NASA Astrophysics Data System (ADS)

    Nagai, T.; Uchino, O.; Itabe, T.; Shibata, T.; Mizutani, K.; Fujimoto, T.

    1997-09-01

    A lidar system was installed at Eureka (80°N, 86°W) in January 1993 to monitor stratospheric aerosols and polar stratospheric clouds (PSCs). In the winter of 1994/1995, PSCs were found at altitudes of around 20km in the middle of December. In early January 1995, PSCs were observed at altitudes from 14.3 km to 16 km, where the temperature ranged from 199K to 202K. Since this range is higher than the frost point of nitric acid trihydrate (NAT), the particles in these PSCs may have consisted of sulfuric acid tetrahydrate (SAT).

  17. Genome Sequence of a Candidate World Health Organization Reference Strain of Zika Virus for Nucleic Acid Testing

    PubMed Central

    Trösemeier, Jan-Hendrik; Musso, Didier; Blümel, Johannes; Thézé, Julien; Pybus, Oliver G.

    2016-01-01

    We report here the sequence of a candidate reference strain of Zika virus (ZIKV) developed on behalf of the World Health Organization (WHO). The ZIKV reference strain is intended for use in nucleic acid amplification (NAT)-based assays for the detection and quantification of ZIKV RNA. PMID:27587826

  18. Genome Sequence of a Candidate World Health Organization Reference Strain of Zika Virus for Nucleic Acid Testing.

    PubMed

    Trösemeier, Jan-Hendrik; Musso, Didier; Blümel, Johannes; Thézé, Julien; Pybus, Oliver G; Baylis, Sally A

    2016-01-01

    We report here the sequence of a candidate reference strain of Zika virus (ZIKV) developed on behalf of the World Health Organization (WHO). The ZIKV reference strain is intended for use in nucleic acid amplification (NAT)-based assays for the detection and quantification of ZIKV RNA. PMID:27587826

  19. A simple and cost-saving approach to optimize the production of subtilisin NAT by submerged cultivation of Bacillus subtilis natto.

    PubMed

    Ku, Ting-Wei; Tsai, Ruei-Lan; Pan, Tzu-Ming

    2009-01-14

    Subtilisin NAT, formerly designated nattokinase or subtilisin BSP, is a potent cardiovascular drug because of its strong fibrinolytic activity and safety. In this study, one Bacillus subtilis natto strain with high fibrinolytic activity was isolated. We further studied the optimal conditions for subtilisin NAT production by submerged cultivation and three variables/three levels of response surface methodology (RSM) using various inoculum densities, glucose concentrations, and defatted soybean concentrations as the three variables. According to the RSM analysis, while culturing by 2.93% defatted soybean, 1.75% glucose, and 4.00% inoculum density, we obtained an activity of 13.78 SU/mL. Processing the batch fermentation with this optimal condition, the activity reached 13.69 SU/mL, which is equal to 99.3% of the predicted value. PMID:19063639

  20. Independent isotopic yields in 25 MeV and 50 MeV proton-induced fission of natU

    NASA Astrophysics Data System (ADS)

    Penttilä, H.; Gorelov, D.; Elomaa, V.-V.; Eronen, T.; Hager, U.; Hakala, J.; Jokinen, A.; Kankainen, A.; Karvonen, P.; Moore, I. D.; Parkkonen, J.; Peräjärvi, K.; Pohjalainen, I.; Rahaman, S.; Rinta-Antila, S.; Rissanen, J.; Rubchenya, V. A.; Saastamoinen, A.; Simutkin, V.; Sonoda, T.; Weber, C.; Voss, A.; Äystö, J.

    2016-04-01

    Independent isotopic yields for elements from Zn to La in the 25 MeV proton-induced fission of {}^{nat}U were determined with the JYFLTRAP facility. In addition, isotopic yields for Zn, Ga, Rb, Sr, Zr, Pd and Xe in the 50 MeV proton-induced fission of {}^{nat}U were measured. The deduced isotopic yield distributions are compared with a Rubchenya model, the GEF model with universal parameters and the semi-empirical Wahl model. Of these, the Rubchenya model gives the best overall agreement with the obtained data. Combining the isotopic yield data with mass yield data to obtain the absolute independent yields was attempted. The result depends on the mass yield distribution.

  1. Active cigarette smoking and the risk of breast cancer at the level of N-acetyltransferase 2 (NAT2) gene polymorphisms.

    PubMed

    Kasajova, Petra; Holubekova, Veronika; Mendelova, Andrea; Lasabova, Zora; Zubor, Pavol; Kudela, Erik; Biskupska-Bodova, Kristina; Danko, Jan

    2016-06-01

    The aim of our study was to assess the correlation between the tobacco exposure and NAT2 gene (rs1041983 C/T, rs1801280 T/C, rs1799930 G/A) polymorphisms in association with breast cancer development. We wanted to determine the prognostic clinical importance of these polymorphisms in association with smoking and breast cancer. For the detection of possible association between smoking, NAT2 gene polymorphisms, and the risk of breast cancer, we designed a case-controlled study with 198 patients enrolled, 98 breast cancer patients and 100 healthy controls. Ten milliliters of peripheral blood from the cubital vein was withdrawn from every patient. The HRM (high resolution melting) analysis was used for the detection of three abovementioned NAT2 gene polymorphisms. When comparing a group of women smoking more than 5 cigarettes a day with the patients smoking fewer than 5 cigarettes a day, we found out that if women were the carriers of aberrant AA genotype for rs1799930, the first group of women had higher risk of breast carcinoma than the second group. If patients were the carriers of aberrant TT genotype for rs1041983, for rs1801280CC genotype, and rs1799930AA genotype and they smoked more than 5 cigarettes a day, they had higher risk of malignant breast disease than never-smoking women. Our results confirm the hypothesis that NAT2 gene polymorphisms (rs1041983 C/T, rs1801280 T/C, and rs1799930 G/A) in association with long-period active smoking could be the possible individual risk-predicting factors for breast cancer development in the population of Slovak women. PMID:26700672

  2. Refinement of the prediction of N-acetyltransferase 2 (NAT2) phenotypes with respect to enzyme activity and urinary bladder cancer risk.

    PubMed

    Selinski, Silvia; Blaszkewicz, Meinolf; Ickstadt, Katja; Hengstler, Jan G; Golka, Klaus

    2013-12-01

    Polymorphisms of N-acetyltransferase 2 (NAT2) are well known to modify urinary bladder cancer risk as well as efficacy and toxicity of pharmaceuticals via reduction in the enzyme's acetylation capacity. Nevertheless, the discussion about optimal NAT2 phenotype prediction, particularly differentiation between different degrees of slow acetylation, is still controversial. Therefore, we investigated the impact of single nucleotide polymorphisms and their haplotypes on slow acetylation in vivo and on bladder cancer risk. For this purpose, we used a study cohort of 1,712 bladder cancer cases and 2,020 controls genotyped for NAT2 by RFLP-PCR and for the tagSNP rs1495741 by TaqMan(®) assay. A subgroup of 344 individuals was phenotyped by the caffeine test in vivo. We identified an 'ultra-slow' acetylator phenotype based on combined *6A/*6A, *6A/*7B and *7B/*7B genotypes containing the homozygous minor alleles of C282T (rs1041983, *6A, *7B) and G590A (rs1799930, *6A). 'Ultra-slow' acetylators have significantly about 32 and 46 % lower activities of caffeine metabolism compared with other slow acetylators and with the *5B/*5B genotypes, respectively (P < 0.01, both). The 'ultra-slow' genotype showed an association with bladder cancer risk in the univariate analysis (OR = 1.31, P = 0.012) and a trend adjusted for age, gender and smoking habits (OR = 1.22, P = 0.082). In contrast, slow acetylators in general were not associated with bladder cancer risk, neither in the univariate (OR = 1.02, P = 0.78) nor in the adjusted (OR = 0.98, P = 0.77) analysis. In conclusion, this study suggests that NAT2 phenotype prediction should be refined by consideration of an 'ultra-slow' acetylation genotype. PMID:24221535

  3. Coffee and tea consumption, genotype-based CYP1A2 and NAT2 activity and colorectal cancer risk-results from the EPIC cohort study.

    PubMed

    Dik, Vincent K; Bueno-de-Mesquita, H B As; Van Oijen, Martijn G H; Siersema, Peter D; Uiterwaal, Cuno S P M; Van Gils, Carla H; Van Duijnhoven, Fränzel J B; Cauchi, Stéphane; Yengo, Loic; Froguel, Philippe; Overvad, Kim; Bech, Bodil H; Tjønneland, Anne; Olsen, Anja; Boutron-Ruault, Marie-Christine; Racine, Antoine; Fagherazzi, Guy; Kühn, Tilman; Campa, Daniele; Boeing, Heiner; Aleksandrova, Krasimira; Trichopoulou, Antonia; Peppa, Eleni; Oikonomou, Eleni; Palli, Domenico; Grioni, Sara; Vineis, Paolo; Tumino, Rosaria; Panico, Salvatore; Peeters, Petra H M; Weiderpass, Elisabete; Engeset, Dagrun; Braaten, Tonje; Dorronsoro, Miren; Chirlaque, María-Dolores; Sánchez, María-José; Barricarte, Aurelio; Zamora-Ros, Raul; Argüelles, Marcial; Jirström, Karin; Wallström, Peter; Nilsson, Lena M; Ljuslinder, Ingrid; Travis, Ruth C; Khaw, Kay-Tee; Wareham, Nick; Freisling, Heinz; Licaj, Idlir; Jenab, Mazda; Gunter, Marc J; Murphy, Neil; Romaguera-Bosch, Dora; Riboli, Elio

    2014-07-15

    Coffee and tea contain numerous antimutagenic and antioxidant components and high levels of caffeine that may protect against colorectal cancer (CRC). We investigated the association between coffee and tea consumption and CRC risk and studied potential effect modification by CYP1A2 and NAT2 genotypes, enzymes involved in the metabolization of caffeine. Data from 477,071 participants (70.2% female) of the European Investigation into Cancer and Nutrition (EPIC) cohort study were analyzed. At baseline (1992-2000) habitual (total, caffeinated and decaffeinated) coffee and tea consumption was assessed with dietary questionnaires. Cox proportional hazards models were used to estimate adjusted hazard ratio's (HR) and 95% confidence intervals (95% CI). Potential effect modification by genotype-based CYP1A2 and NAT2 activity was studied in a nested case-control set of 1,252 cases and 2,175 controls. After a median follow-up of 11.6 years, 4,234 participants developed CRC (mean age 64.7 ± 8.3 years). Total coffee consumption (high vs. non/low) was not associated with CRC risk (HR 1.06, 95% CI 0.95-1.18) or subsite cancers, and no significant associations were found for caffeinated (HR 1.10, 95% CI 0.97-1.26) and decaffeinated coffee (HR 0.96, 95% CI 0.84-1.11) and tea (HR 0.97, 95% CI 0.86-1.09). High coffee and tea consuming subjects with slow CYP1A2 or NAT2 activity had a similar CRC risk compared to non/low coffee and tea consuming subjects with a fast CYP1A2 or NAT2 activity, which suggests that caffeine metabolism does not affect the link between coffee and tea consumption and CRC risk. This study shows that coffee and tea consumption is not likely to be associated with overall CRC. PMID:24318358

  4. Identification of ta-siRNAs and cis-nat-siRNAs in cassava and their roles in response to cassava bacterial blight.

    PubMed

    Quintero, Andrés; Pérez-Quintero, Alvaro L; López, Camilo

    2013-06-01

    Trans-acting small interfering RNAs (ta-siRNAs) and natural cis-antisense siRNAs (cis-nat-siRNAs) are recently discovered small RNAs (sRNAs) involved in post-transcriptional gene silencing. ta-siRNAs are transcribed from genomic loci and require processing by microRNAs (miRNAs). cis-nat-siRNAs are derived from antisense RNAs produced by the simultaneous transcription of overlapping antisense genes. Their roles in many plant processes, including pathogen response, are mostly unknown. In this work, we employed a bioinformatic approach to identify ta-siRNAs and cis-nat-siRNAs in cassava from two sRNA libraries, one constructed from healthy cassava plants and one from plants inoculated with the bacterium Xanthomonas axonopodis pv. manihotis (Xam). A total of 54 possible ta-siRNA loci were identified in cassava, including a homolog of TAS3, the best studied plant ta-siRNA. Fifteen of these loci were induced, while 39 were repressed in response to Xam infection. In addition, 15 possible cis-natural antisense transcript (cis-NAT) loci producing siRNAs were identified from overlapping antisense regions in the genome, and were found to be differentially expressed upon Xam infection. Roles of sRNAs were predicted by sequence complementarity and our results showed that many sRNAs identified in this work might be directed against various transcription factors. This work represents a significant step toward understanding the roles of sRNAs in the immune response of cassava. PMID:23665476

  5. Dynamic Drusen Remodelling in Participants of the Nutritional AMD Treatment-2 (NAT-2) Randomized Trial

    PubMed Central

    Querques, Giuseppe; Merle, Bénédicte M. J.; Pumariega, Nicole M.; Benlian, Pascale; Delcourt, Cécile; Zourdani, Alain; Leisy, Heather B.; Lee, Michele D.; Smith, R. Theodore; Souied, Eric H.

    2016-01-01

    Purpose To evaluate the dynamic remodeling of drusen in subjects with unilateral neovascular age-related macular degeneration (AMD) receiving a three-year course of oral docosahexaenoic acid (DHA) or placebo. Setting Institutional setting. Methods Three hundred subjects with age-related maculopathy and neovascular AMD in the fellow eye were randomly assigned to receive either 840 mg/day DHA or placebo for 3 years. Main outcome measures of this post-hoc sub-group analysis were progression of drusen number, total diameter, and total area on fundus photography, and their association with DHA supplementation, socio-demographic and genetic characteristics. Results Drusen progression was analyzed in 167 subjects that did not develop CNV (87 that received DHA and 80 that received placebo). None of the drusen remodeling outcomes were significantly associated with DHA supplementation. Total drusen diameter reduction in the inner subfield was significantly associated with age (older patients: r = -0.17; p = 0.003). Women showed a tendency to decreased total drusen diameter in the inner subfield with CFH polymorphism (p = 0.03), where women with TT genotype tended to have a greater reduction in drusen diameter than other genotypes (CC and CT). Drusen area in the inner subfield was more reduced in older patients (r = -0.17) and in women (p = 0.01). Drusen number showed no significant trends. Conclusions Dynamic drusen remodeling with net reduction in drusen load over three years was found in patients with exudative AMD in one eye and drusen in the other eye (study-eye). This reduction was correlated with increased age and female gender, and showed a tendency to be influenced by CFH genotype, but did not appear to be affected by DHA supplementation. Trial Registration Controlled-Trials.com ISRCTN98246501 PMID:26901353

  6. Production of ⁶¹Cu by the natZn(p,α) reaction: Improved separation and specific activity determination by titration with three chelators

    DOE PAGESBeta

    Asad, Ali H.; Smith, Suzanne V.; Morandeau, Laurence M.; Chan, Sun; Jeffery, Charmaine M.; Price, Roger I.

    2015-09-01

    In this study, the cyclotron-based production of position-emitting ⁶¹Cu using the (p,α) reaction at 11.7 MeV was investigated starting from natural-zinc (natZn) and enriched ⁶⁴Zn-foil targets, as well as its subsequent purification. For natZn, a combination of three resins were assessed to separate ⁶¹Cu from contaminating 66,67,68Ga and natZn. The specific activity of the purified ⁶¹Cu determined using ICP-MS analysis ranged from 143.3±14.3(SD) to 506.2±50.6 MBq/μg while the titration method using p-SCN-Bn-DOTA, p-SCN-Bn-NOTA and diamsar gave variable results (4.7±0.2 to 412.5±15.3 MBq/μg), with diamsar lying closest to the ICP-MS values. Results suggest that the p-SCN-Bn-DOTA and p-SCN-Bn-NOTA titration methods aremore » significantly affected by the presence of trace-metal contaminants.« less

  7. Production of ⁶¹Cu by the natZn(p,α) reaction: Improved separation and specific activity determination by titration with three chelators

    SciTech Connect

    Asad, Ali H.; Smith, Suzanne V.; Morandeau, Laurence M.; Chan, Sun; Jeffery, Charmaine M.; Price, Roger I.

    2015-09-01

    In this study, the cyclotron-based production of position-emitting ⁶¹Cu using the (p,α) reaction at 11.7 MeV was investigated starting from natural-zinc (natZn) and enriched ⁶⁴Zn-foil targets, as well as its subsequent purification. For natZn, a combination of three resins were assessed to separate ⁶¹Cu from contaminating 66,67,68Ga and natZn. The specific activity of the purified ⁶¹Cu determined using ICP-MS analysis ranged from 143.3±14.3(SD) to 506.2±50.6 MBq/μg while the titration method using p-SCN-Bn-DOTA, p-SCN-Bn-NOTA and diamsar gave variable results (4.7±0.2 to 412.5±15.3 MBq/μg), with diamsar lying closest to the ICP-MS values. Results suggest that the p-SCN-Bn-DOTA and p-SCN-Bn-NOTA titration methods are significantly affected by the presence of trace-metal contaminants.

  8. Excitation functions of proton induced reactions on natOs up to 65 MeV: Experiments and comparison with results from theoretical codes

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Adam Rebeles, R.; Tárkányi, F.; Takács, S.

    2015-02-01

    Activation of thin natOs targets, electrodeposited on Ni backings, was investigated for the first time in stacked foil irradiations with 65 MeV and 34 MeV proton beams. Assessments of the produced radionuclides by high resolution gamma-ray spectroscopy yielded excitation functions for formation of 184, 185, 186m,m+g, 187m+g, 188m+g, 189m2+m1+g, 190m2,m1+g, 192m1+gIr and 185cum, 191m+gOs, 183m+gRe. Where available comparisons with the reaction cross sections obtained in 2 earlier studies on enriched 192Os were made. Reduced uncertainty on cross sections is obtained by simultaneous remeasurement of the 27Al(p,x)22,24Na, natNi(p,x)57Ni and natTi(p,x)48V monitor reactions over wide relevant energy ranges. Confirmation of monitoring took place by assessment of excitation functions of 61Cu, 56Ni, 55,56,57,58Co and 52Mn induced in the Ni backings and comparison with a recent compilation for most of these radionuclides. Contributing reactions and overall cross sections are discussed and were evaluated in comparison with the results of the theoretical code TALYS 1.6 (values from the on-line library TENDL-2013).

  9. Freezing of stratospheric aerosol droplets

    NASA Astrophysics Data System (ADS)

    Luo, Beiping; Peter, Thomas; Crutzen, Paul

    Theoretical calculations are presented for homogeneous and heterogeneous freezing of sulfuric acid droplets under stratospheric conditions, based on classical nucleation theory. In contrast to previous results it is shown that a prominent candidate for freezing, sulfuric acid tetrahydrate (SAT ≡ H2SO4·4H2O), does not freeze homogeneously. The theoretical results limit the homogeneous freezing rate at 200 K to much less than 1 cm-3s-1, a value that may be estimated from bulk phase laboratory experiments. This suggests that the experimental value is likely to be a measure of heterogeneous, not homogeneous nucleation. Thus, under statospheric conditions, freezing of SAT can only occur in the presence of suitable nuclei; however, even for heterogeneous nucleation experimental results impose strong constraints. Since a nitric acid trihydrate (NAT) embryo probably needs a solid body for nucleation, these results put an important constraint on the theory of NAT formation in polar stratospheric clouds.

  10. Dimensionality and predictive validity of the HAM-Nat, a test of natural sciences for medical school admission

    PubMed Central

    2011-01-01

    Background Knowledge in natural sciences generally predicts study performance in the first two years of the medical curriculum. In order to reduce delay and dropout in the preclinical years, Hamburg Medical School decided to develop a natural science test (HAM-Nat) for student selection. In the present study, two different approaches to scale construction are presented: a unidimensional scale and a scale composed of three subject specific dimensions. Their psychometric properties and relations to academic success are compared. Methods 334 first year medical students of the 2006 cohort responded to 52 multiple choice items from biology, physics, and chemistry. For the construction of scales we generated two random subsamples, one for development and one for validation. In the development sample, unidimensional item sets were extracted from the item pool by means of weighted least squares (WLS) factor analysis, and subsequently fitted to the Rasch model. In the validation sample, the scales were subjected to confirmatory factor analysis and, again, Rasch modelling. The outcome measure was academic success after two years. Results Although the correlational structure within the item set is weak, a unidimensional scale could be fitted to the Rasch model. However, psychometric properties of this scale deteriorated in the validation sample. A model with three highly correlated subject specific factors performed better. All summary scales predicted academic success with an odds ratio of about 2.0. Prediction was independent of high school grades and there was a slight tendency for prediction to be better in females than in males. Conclusions A model separating biology, physics, and chemistry into different Rasch scales seems to be more suitable for item bank development than a unidimensional model, even when these scales are highly correlated and enter into a global score. When such a combination scale is used to select the upper quartile of applicants, the proportion of

  11. On the theories of type 1 polar stratospheric cloud formation

    NASA Astrophysics Data System (ADS)

    MacKenzie, A. Robert; Kulmala, Markku; Laaksonen, Ari; Vesala, Timo

    1995-06-01

    Several mechanisms for the production of polar stratospheric cloud (PSC) particles are investigated using the classical theories of nucleation and freezing and the multicomponent condensation theory. These mechanisms invoke particle compositions ranging from binary (H2SO4/H2O) solution, solid sulfuric acid tetrahydrate (SAT) and ternary (HNO3/H2O/H2SO4) solution to binary (HNO3/H2O) solution and solid nitric acid trihydrate (NAT). Empirical relations, derived from classical nucleation studies, are used to calculate the surface energies required in calculations of nucleation and freezing. Using these data, we calculate that the nucleation of nitric acid solutions or solid phases onto SAT particles is not efficient. Homogeneous freezing of SAT or NAT from ternary solutions does not occur under stratospheric conditions. Homogeneous freezing of water ice can occur at temperatures near the frost point of pure water. Heterogeneous freezing is a strong function of the contact parameter between the emergent crystal and the initiating seed particle. Heterogeneous freezing of the stratospheric aerosol to SAT and NAT at temperatures above the frost point is not ruled out by our calculations. If formed, NAT can deplete the gas phase nitric acid concentration, by condensational growth, more efficiently than ternary droplets. We conclude that the most likely route to type 1 PSC particles is via condensational growth of ternary solution droplets followed by rapid freezing to NAT, SAT, and water ice at temperatures near the ice frost point. The particles formed are then stable and can reduce nitric acid vapor pressures to the saturation vapor pressure over NAT at all temperatures below the NAT point. Such a mechanism is consistent with observations.

  12. Microphysical Modelling of the 1999-2000 Arctic Winter. 3; Impact of Homogeneous Freezing on PSCs

    NASA Technical Reports Server (NTRS)

    Drdla, K.

    2003-01-01

    Simulations of the 1999-2000 winter have tested the effect on polar stratospheric clouds (PSCs) of the homogeneous freezing of liquid ternary solutions into nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD). Proposed laboratory-derived volume-based and surface-based homogeneous freezing rates have both been examined, including different assumptions about the extrapolation of laboratory measurements to atmospheric conditions. Widespread PSC formation and denitrification are possible in several of the scenarios examined. However, the simulations are all unable to explain the solid-phase PSCs observed early in the 1999-2000 winter, and are unable to reproduce the measured extent of vortex denitrification. These problems can both be attributed to the relatively cold temperatures, more than 5 K below the NAT condensation point, necessary for effective homogeneous freezing. Therefore synoptic-scale homogeneous freezing appears unlikely to be the primary mechanism responsible for solid-phase PSC formation.

  13. ERBE S7 NAT

    Atmospheric Science Data Center

    2016-06-15

    ... scanner instruments on board the NOAA-9 and NOAA-10 satellites provide global coverage, while the ERBE scanner instrument onboard ... have 136-degree FOV on ERBS and 126-degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  14. ERBE S8 NAT

    Atmospheric Science Data Center

    2016-06-15

    ... ERBE instruments on board the NOAA-9 and NOAA-10 satellites provide global spatial coverage, while the scanner instruments on ... have 136-degree FOV on ERBS and 126-degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  15. Remembering Nat Schoenfeld

    PubMed Central

    Catania, A. Charles

    1997-01-01

    William Nathan Schoenfeld was born in New York City on December 6, 1915, and died in Sun City West, Arizona, on August 3, 1996. He was an undergraduate at the College of the City of New York, where he received a BS degree in 1937. He received his PhD from Columbia University in 1942 and then continued there as a faculty member, advancing from lecturer to full professor. In 1966 he moved to Queens College of the City University of New York, where he remained until his retirement in 1983. During his years at Queens, he also took on visiting appointments in Brazil, Mexico, and Venezuela. In retirement, he spent roughly a decade in Israel, where he occasionally taught as a visiting professor at the Hebrew University of Jerusalem. He returned to the United States for his final years. He is survived by his wife, Melanie, their three children, Rivka, Joshua and Naomi, and a son, Mark, from a previous marriage.

  16. Flavonoids and 5-Aminosalicylic Acid Inhibit the Formation of Neutrophil Extracellular Traps

    PubMed Central

    Möller, Sonja; Klinger, Matthias; Solbach, Werner; Laskay, Tamás

    2013-01-01

    Neutrophil extracellular traps (NETs) have been suggested to play a pathophysiological role in several autoimmune diseases. Since NET-formation in response to several biological and chemical stimuli is mostly ROS dependent, in theory any substance that inhibits or scavenges ROS could prevent ROS-dependent NET release. Therefore, in the present comprehensive study, several antioxidative substances were assessed for their capacity to inhibit NET formation of primary human neutrophils in vitro. We could show that the flavonoids (−)-epicatechin, (+)-catechin hydrate, and rutin trihydrate as well as vitamin C and the pharmacological substances N-acetyl-L-cysteine and 5-aminosalicylic acid inhibited PMA induced ROS production and NET formation. Therefore, a broad spectrum of antioxidative substances that reduce ROS production of primary human neutrophils also inhibits ROS-dependent NET formation. It is tempting to speculate that such antioxidants can have beneficial therapeutic effects in diseases associated with ROS-dependent NET formation. PMID:24381411

  17. Fragment charge and energy distributions in the 1.8-4.8 GeV {sup 3}He + {sup nat}Ag, {sup 197}Au reactions

    SciTech Connect

    Bracken, D.S.; Foxford, E.R.; Kwiatkowski, K.

    1995-10-01

    Moving source fits have been performed for IMFs as a function of observables related to collision violence in the 1.8-4.8 GeV {sup 3}He +{sup nat}Ag, {sup l97}Au reactions. The systematic behavior of the source properties and fragment charge distributions will be reviewed. The evolution of the spectral Coulomb parameters provides evidence for nuclear expansion prior to multifragmentation, suggesting a breakup density of p/p{sub o} {approximately} 1/3. The charge distributions will be examined in terms of power-law fits and moment analyses.

  18. Computational investigation of ⁹⁹Mo production yield via proton irradiation of natU and ²³²Th targets.

    PubMed

    Mirvakili, Seyed Mohammad; Alizadeh, Masoumeh; Vaziri, Atyeh Joze; Gholamzadeh, Zohreh; Davari, Amin

    2015-07-01

    Accelerators have some advantages such as safety and cheaper operating and decommissioning costs for (99)Mo production. Yield theoretical calculation using computational codes can powerfully estimate usefulness of a proposed nuclear reaction for a routine manufacturing. In this work, Monte Carlo-based code was used to compute (99)Mo yield in (232)Th and (nat)U proton-irradiated targets, as well as maximum applicable beam current. Results showed that the code well agrees with published experimental data. The targets can bear maximum beam current of 30 µA. Targets from (232)Th provides higher (99)Mo yield. PMID:25898237

  19. GST, NAT, SULT1A1, CYP1B1 genetic polymorphisms, interactions with environmental exposures and bladder cancer risk in a high-risk population.

    PubMed

    Hung, Rayjean J; Boffetta, Paolo; Brennan, Paul; Malaveille, Christian; Hautefeuille, Agnès; Donato, Francesco; Gelatti, Umberto; Spaliviero, Massimiliano; Placidi, Donatella; Carta, Angela; Scotto di Carlo, Antonio; Porru, Stefano

    2004-07-01

    Tobacco smoking and occupation are major risk factors of bladder cancer via exposure to polycyclic aromatic hydrocarbons (PAHs) and aromatic amines. Glutathione S-transferase (GST) M1, T1 and P1 are involved in the detoxification of PAH reactive metabolites. Two N-acetyltransferase isozymes, NAT2 and NAT1, have major roles in catalyzing the N-acetylation and O-acetylation of aromatic amines. Cytochrome p450 1B1 (CYP1B1) and sulfotransferase 1A1 (SULT1A1) are also involved in the metabolism of PAHs and aromatic amines. It is hypothesized that the genetic polymorphisms of these metabolic enzymes have an effect on the individual susceptibility to bladder cancer in particular by interacting with relevant environmental exposures. A hospital-based case-control study among men in Brescia, Northern Italy recruited 201 incidence cases and 214 controls from 1997-2000. Occupational exposures were blindly coded by occupational physicians. Genotyping of polymorphisms were carried out with PCR-RFLP method. Unconditional multivariate logistic regression was applied to model the association between genetic polymorphisms and bladder cancer risk. Effect modifications by age of onset, smoking and occupational exposures to PAHs and aromatic amines were evaluated. We also conducted an analysis of interaction between genetic factors. GSTM1 and GSTT1 null genotype were associated with an increased risk of bladder cancer with an odds ratio (OR) of 1.69 (95% confidence interval [CI] = 1.11-2.56) and 1.74 (95% CI = 1.02-2.95), respectively. The effect of GSTM1 null was seen particularly in heavy smokers, and there was a combined effect with occupational exposure of aromatic amines (OR = 2.77, 95% CI = 1.08-7.10). We observed a trend (p-value < 0.01) of increasing cancer risk comparing subjects with normal GSTM1 and T1 activity to subjects with one (OR = 1.82, 95% CI = 1.16-2.85) or both null genotypes (OR = 2.58, 95% CI = 1.27-5.23). NAT2 slow acetylator was associated with marginally

  20. Yeast display evolution of a kinetically efficient 13-amino acid substrate for lipoic acid ligase

    PubMed Central

    Puthenveetil, Sujiet; Liu, Daniel S.; White, Katharine A.; Thompson, Samuel; Ting, Alice Y.

    2009-01-01

    E. coli lipoic acid ligase (LplA) catalyzes ATP-dependent covalent ligation of lipoic acid onto specific lysine sidechains of three acceptor proteins involved in oxidative metabolism. Our lab has shown that LplA and engineered mutants can ligate useful small-molecule probes such as alkyl azides (Nat. Biotechnol. 2007, 25, 1483–1487) and photocrosslinkers (Angew. Chem Int. Ed Engl. 2008, 47, 7018–7021) in place of lipoic acid, facilitating imaging and proteomic studies. Both to further our understanding of lipoic acid metabolism, and to improve LplA’s utility as a biotechnological platform, we have engineered a novel 13-amino acid peptide substrate for LplA. LplA’s natural protein substrates have a conserved β-hairpin structure, a conformation that is difficult to recapitulate in a peptide, and thus we performed in vitro evolution to engineer the LplA peptide substrate, called “LplA Acceptor Peptide” (LAP). A ~107 library of LAP variants was displayed on the surface of yeast cells, labeled by LplA with either lipoic acid or bromoalkanoic acid, and the most efficiently labeled LAP clones were isolated by fluorescence activated cell sorting. Four rounds of evolution followed by additional rational mutagenesis produced a “LAP2” sequence with a kcat/Km of 0.99 μM−1min−1, >70-fold better than our previous rationally-designed 22-amino acid LAP1 sequence (Nat. Biotechnol. 2007, 25, 1483–1487), and only 8-fold worse than the kcat/Km values of natural lipoate and biotin acceptor proteins. The kinetic improvement over LAP1 allowed us to rapidly label cell surface peptide-fused receptors with quantum dots. PMID:19863063

  1. Systematic Evaluation of Different Nucleic Acid Amplification Assays for Cytomegalovirus Detection: Feasibility of Blood Donor Screening.

    PubMed

    Vollmer, T; Knabbe, C; Dreier, J

    2015-10-01

    Acute primary cytomegalovirus (CMV) infections, which commonly occur asymptomatically among blood donors, represent a significant risk for serious morbidity in immunocompromised patients (a major group of transfusion recipients). We implemented a routine CMV pool screening procedure for plasma for the identification of CMV DNA-positive donors, and we evaluated the sensitivities and performance of different CMV DNA amplification systems. Minipools (MPs) of samples from 18,405 individual donors (54,451 donations) were screened for CMV DNA using the RealStar CMV PCR assay (Altona Diagnostic Technologies), with a minimum detection limit of 11.14 IU/ml. DNA was extracted with a high-volume protocol (4.8 ml, Chemagic Viral 5K kit; PerkinElmer) for blood donor pool screening (MP-nucleic acid testing [NAT]) and with the Nuclisens easyMAG system (0.5 ml; bioMérieux) for individual donation (ID)-NAT. In total, six CMV DNA-positive donors (0.03%) were identified by routine CMV screening, with DNA concentrations ranging from 4.35 × 10(2) to 4.30 × 10(3) IU/ml. Five donors already showed seroconversion and detectable IgA, IgM, and/or IgG antibody titers (IgA(+)/IgM(+)/IgG(-) or IgA(+)/IgM(+)/IgG(+)), and one donor showed no CMV-specific antibodies. Comparison of three commercial assays, i.e., the RealStar CMV PCR kit, the Sentosa SA CMV quantitative PCR kit (Vela Diagnostics), and the CMV R-gene PCR kit (bioMérieux), for MP-NAT and ID-NAT showed comparably good analytical sensitivities, ranging from 10.23 to 11.14 IU/ml (MP-NAT) or from 37.66 to 57.94 IU/ml (ID-NAT). The clinical relevance of transfusion-associated CMV infections requires further investigation, and the evaluated methods present powerful basic tools providing sensitive possibilities for viral testing. The application of CMV MP-NAT facilitated the identification of one donor with a window-phase donation during acute primary CMV infection. PMID:26202109

  2. Hybrid Formulations of Liposomes and Bioadhesive Polymers Improve the Hypotensive Effect of the Melatonin Analogue 5-MCA-NAT in Rabbit Eyes

    PubMed Central

    Palma, Santiago; Allemandi, Daniel; Herrero-Vanrell, Rocío; Molina-Martínez, Irene T.

    2014-01-01

    For the treatment of chronic ocular diseases such as glaucoma, continuous instillations of eye drops are needed. However, frequent administrations of hypotensive topical formulations can produce adverse ocular surface effects due to the active substance or other components of the formulation, such as preservatives or other excipients. Thus the development of unpreserved formulations that are well tolerated after frequent instillations is an important challenge to improve ophthalmic chronic topical therapies. Furthermore, several components can improve the properties of the formulation in terms of efficacy. In order to achieve the mentioned objectives, we have developed formulations of liposomes (150–200 nm) containing components similar to those in the tear film and loaded with the hypotensive melatonin analog 5-methoxycarbonylamino-N-acetyltryptamine (5-MCA-NAT, 100 µM). These formulations were combined with mucoadhesive (sodium hyaluronate or carboxymethylcellulose) or amphiphilic block thermosensitive (poloxamer) polymers to prolong the hypotensive efficacy of the drug. In rabbit eyes, the decrease of intraocular pressure with 5-MCA-NAT-loaded liposomes that were dispersed with 0.2% sodium hyaluronate, 39.1±2.2%, was remarkably higher compared to other liposomes formulated without or with other bioadhesive polymers, and the effect lasted more than 8 hours. According to the results obtained in the present work, these technological strategies could provide an improved modality for delivering therapeutic agents in patients with glaucoma. PMID:25329636

  3. Affinity of (nat/68)Ga-Labelled Curcumin and Curcuminoid Complexes for β-Amyloid Plaques: Towards the Development of New Metal-Curcumin Based Radiotracers.

    PubMed

    Rubagotti, Sara; Croci, Stefania; Ferrari, Erika; Iori, Michele; Capponi, Pier C; Lorenzini, Luca; Calzà, Laura; Versari, Annibale; Asti, Mattia

    2016-01-01

    Curcumin derivatives labelled with fluorine-18 or technetium-99m have recently shown their potential as diagnostic tools for Alzheimer's disease. Nevertheless, no study by exploiting the labelling with gallium-68 has been performed so far, in spite of its suitable properties (positron emitter, generator produced radionuclide). Herein, an evaluation of the affinity for synthetic β-amyloid fibrils and for amyloid plaques of three (nat/68)Ga-labelled curcumin analogues, namely curcumin curcumin (CUR), bis-dehydroxy-curcumin (bDHC) and diacetyl-curcumin (DAC), was performed. Affinity and specificity were tested in vitro on amyloid synthetic fibrils by using gallium-68 labelled compounds. Post-mortem brain cryosections from Tg2576 mice were used for the ex vivo visualization of amyloid plaques. The affinity of (68)Ga(CUR)₂⁺, (68)Ga(DAC)₂⁺, and (68)Ga(bDHC)₂⁺ for synthetic β-amyloid fibrils was moderate and their uptake could be observed in vitro. On the other hand, amyloid plaques could not be visualized on brain sections of Tg2576 mice after injection, probably due to the low stability of the complexes in vivo and of a hampered passage through the blood-brain barrier. Like curcumin, all (nat/68)Ga-curcuminoid complexes maintain a high affinity for β-amyloid plaques. However, structural modifications are still needed to improve their applicability as radiotracers in vivo. PMID:27608011

  4. H2SO4/HNO3/H2O Phase Diagram in Regions of Stratospheric Importance

    NASA Astrophysics Data System (ADS)

    Beyer, K. D.; Hansen, A. R.; Raddatz, N.

    2003-12-01

    We have investigated the region of the H2SO4/HNO3/H2O ternary liquid/solid phase diagram bounded by ice, nitric acid trihydrate (NAT), and sulfuric acid tetrahydrate (SAT) using differential scanning calorimetry (DSC) and infrared spectroscopy of thin films. We report measurements and analysis of the eutectic melting curves in the ternary system of the hydrates mentioned as well as the temperature of the eutectics: ice/SAT/NAT, ice/sulfuric acid hemihexahydrate (SAH)/NAT, and SAT/NAT. We report for the first time an analysis of the content of the solid phase of completely frozen samples and find that sulfuric acid octahydrate (SAO) is often present in frozen ternary samples and can be a significant portion of the solid phase. We provide a description of how the melting path of a frozen ternary sample can be predicted using the ternary phase diagram. We have parameterized our melting point data and provide equations to generate the ternary melting surface. Finally, we compare our results to the historic work of Carpenter & Lehrmann (Carpenter, C. D.; Lehrman, A. Trans. AIChE 1925, 17, 35) and to other more recent work.

  5. A coupled decadal-scale air-sea interaction theory: the NAT-NAO-AMO-AMOC coupled mode and its global impacts

    NASA Astrophysics Data System (ADS)

    Li, Jianping; Sun, Cheng; Jin, Fei-Fei

    2016-04-01

    Observational analysis shows that the North Atlantic Oscillation (NAO) leads the oceanic Atlantic Multidecadal Oscillation (AMO) by 15-20 years and the latter also leads the former by around 15 years. The Community Climate System Model (CCSM) version 4 is employed to investigate the relevant mechanism in the linkage between the NAO and AMO. The results show that the positive North Atlantic Oscillation (NAO) forces the strengthening of the Atlantic meridional overturning circulation (AMOC) and induces a basin-wide uniform sea surface temperature (SST) warming that corresponds to the Atlantic multidecadal oscillation (AMO). The SST field exhibits a delayed response to the preceding enhanced AMOC, and shows a pattern similar to the North Atlantic tripole (NAT), with SST warming in the northern North Atlantic and cooling in the southern part. This SST pattern (negative NAT phase) may lead to an atmospheric response that resembles the negative NAO phase, and subsequently the oscillation proceeds, but in the opposite sense. This implies a NAO-AMO-AMOC coupled mode in decadal scale. Based on these mechanisms, a simple delayed oscillator model is established to explain the quasi-periodic multidecadal variability of the NAO. The magnitude of the NAO forcing of the AMOC/AMO and the time delay of the AMOC/AMO feedback are two key parameters of the delayed oscillator. For a given set of parameters, the quasi 60-year cycle of the NAO can be well predicted. This delayed oscillator model is useful for understanding of the oscillatory mechanism of the NAO, which has significant potential for decadal predictions as well as the interpretation of proxy data records. The NAT-NAO-AMO-AMOC coupled mode has important influences on global and regional climate. The twentieth century Northern Hemisphere mean surface temperature (NHT) is characterized by a multidecadal warming-cooling-warming pattern followed by a flat trend since about 2000 (recent warming hiatus). Here we demonstrate that

  6. Microfluidic devices for nucleic acid (NA) isolation, isothermal NA amplification, and real-time detection.

    PubMed

    Mauk, Michael G; Liu, Changchun; Sadik, Mohamed; Bau, Haim H

    2015-01-01

    Molecular (nucleic acid)-based diagnostics tests have many advantages over immunoassays, particularly with regard to sensitivity and specificity. Most on-site diagnostic tests, however, are immunoassay-based because conventional nucleic acid-based tests (NATs) require extensive sample processing, trained operators, and specialized equipment. To make NATs more convenient, especially for point-of-care diagnostics and on-site testing, a simple plastic microfluidic cassette ("chip") has been developed for nucleic acid-based testing of blood, other clinical specimens, food, water, and environmental samples. The chip combines nucleic acid isolation by solid-phase extraction; isothermal enzymatic amplification such as LAMP (Loop-mediated AMPlification), NASBA (Nucleic Acid Sequence Based Amplification), and RPA (Recombinase Polymerase Amplification); and real-time optical detection of DNA or RNA analytes. The microfluidic cassette incorporates an embedded nucleic acid binding membrane in the amplification reaction chamber. Target nucleic acids extracted from a lysate are captured on the membrane and amplified at a constant incubation temperature. The amplification product, labeled with a fluorophore reporter, is excited with a LED light source and monitored in situ in real time with a photodiode or a CCD detector (such as available in a smartphone). For blood analysis, a companion filtration device that separates plasma from whole blood to provide cell-free samples for virus and bacterial lysis and nucleic acid testing in the microfluidic chip has also been developed. For HIV virus detection in blood, the microfluidic NAT chip achieves a sensitivity and specificity that are nearly comparable to conventional benchtop protocols using spin columns and thermal cyclers. PMID:25626529

  7. Criticality Safety Analysis on the Mixed Be, Nat-U, and C (Graphite) Reflectors in 55-Gallon Waste Drums and Their Equivalents for HWM Applications

    SciTech Connect

    Chou, P

    2011-12-14

    The objective of this analysis is to develop and establish the technical basis on the criticality safety controls for the storage of mixed beryllium (Be), natural uranium (Nat-U), and carbon (C)/graphite reflectors in 55-gallon waste containers and/or their equivalents in Hazardous Waste Management (HWM) facilities. Based on the criticality safety limits and controls outlined in Section 3.0, the operations involving the use of mixed-reflector drums satisfy the double-contingency principle as required by DOE Order 420.1 and are therefore criticality safe. The mixed-reflector mass limit is 120 grams for each 55-gallon drum or its equivalent. a reflector waiver of 50 grams is allowed for Be, Nat-U, or C/graphite combined. The waived reflectors may be excluded from the reflector mass calculations when determining if a drum is compliant. The mixed-reflector drums are allowed to mix with the typical 55-gallon one-reflector drums with a Pu mass limit of 120 grams. The fissile mass limit for the mixed-reflector container is 65 grams of Pu equivalent each. The corresponding reflector mass limits are 300 grams of Be, and/or 100 kilograms of Nat-U, and/or 110 kilograms of C/graphite for each container. All other unaffected control parameters for the one-reflector containers remain in effect for the mixed-reflector drums. For instance, Superior moderators, such as TrimSol, Superla white mineral oil No. 9, paraffin, and polyethylene, are allowed in unlimited quantities. Hydrogenous materials with a hydrogen density greater than 0.133 gram/cc are not allowed. Also, an isolation separation of no less than 76.2 cm (30-inch) is required between a mixed array and any other array. Waste containers in the action of being transported are exempted from this 76.2-cm (30-inch) separation requirement. All deviations from the CS controls and mass limits listed in Section 3.0 will require individual criticality safety analyses on a case-by-case basis for each of them to confirm their

  8. CASTNet mountain acid deposition monitoring program

    SciTech Connect

    Bowser, J.J.; Anderson, J.B.; Edgerton, E.S.; Mohnen, V.; Baumgardener, R.

    1994-12-31

    Concern over the influence of air pollution on forest decline has led the USEPA to establish the Mountain Acid Deposition Monitoring Program (MADMP) to quantify total deposition at high altitudes, i.e., above cloud base. Clouds can be a major source of atmospheric deposition to sensitive, mountain ecosystems. This program is a part of the Clean Air Status and Trends Network (CASTNet), a national assessment of the effects of the 1990 Clean Air Act. The objectives of MADMP are to estimate total deposition, measure cloud chemistry, and characterize spacial and temporal trends at four selected high altitude sites in the Eastern US. Four MADMP sites have been established for the 1994 field season: Clingman`s Dome, Great Smoky Mountain Nat. Park, TN; Slide Mountain, Catskill State Park, NY; Whiteface Mountain, Adirondack State Park, NY; and Whitetop Mountain, Mt. Rogers Nat`l Recreational Area, VA. An automated cloud collection system will be utilized in combination with continuous measurements of cloud liquid water content in order to estimate cloudwater deposition. Other relevant data will include continuous meteorological measurements, ozone and sulfur dioxide concentrations, wet deposition from rainfall analysis, and dry deposition from filter pack analysis. Quality assurance and quality control measures will be employed to maximize accuracy and precision.

  9. Production cross sections of products in the proton induced reactions on natNd in the energy region up to 45 MeV

    NASA Astrophysics Data System (ADS)

    Yang, Sung-Chul; Kim, Kwangsoo; Song, Tae-Yung; Lee, Young-Ouk; Kim, Guinyun

    2015-11-01

    The production cross sections of 141,143,144,146,148m,148g,149,150Pm, 139m,147,149Nd, 138m,142gPr, and 139gCe in the natNd(p,x) reactions were determined by a stacked-foil activation technique for the proton energy range up to 45 MeV using the MC-50 cyclotron of Korea Institute of Radiological and Medical Sciences. The measured cross sections were compared with literature data as well as data from the TENDL-2014 library based on TALYS 1.6. The production cross sections of the above radionuclides are slightly higher than the literature data but are in general agreement with values in TENDL-2014 library except for 148mPm, 148gPm, 139mNd, and 142gPr. The thick target integral yields of the produced radionuclides were also deducted from the measured cross sections.

  10. Neutron-induced fission cross section of {sup nat}Pb and {sup 209}Bi from threshold to 1 GeV: An improved parametrization

    SciTech Connect

    Tarrio, D.; Duran, I.; Paradela, C.; Tassan-Got, L.; Audouin, L.; Berthier, B.; Ferrant, L.; Isaev, S.; Le Naour, C.; Stephan, C.; Trubert, D.; David, S.; Aerts, G.; Andriamonje, S.; Berthoumieux, E.

    2011-04-15

    Neutron-induced fission cross sections for {sup nat}Pb and {sup 209}Bi were measured with a white-spectrum neutron source at the CERN Neutron Time-of-Flight (n{sub T}OF) facility. The experiment, using neutrons from threshold up to 1 GeV, provides the first results for these nuclei above 200 MeV. The cross sections were measured relative to {sup 235}U and {sup 238}U in a dedicated fission chamber with parallel plate avalanche counter detectors. Results are compared with previous experimental data. Upgraded parametrizations of the cross sections are presented, from threshold energy up to 1 GeV. The proposed new sets of fitting parameters improve former results along the whole energy range.

  11. NO3- Coordination in Aqueous Solutions by 15N/14N and 18O/natO Isotopic Substitution: What Can We Learn from Molecular Simulation?

    DOE PAGESBeta

    Chialvo, Ariel A.; Vlcek, Lukas

    2014-12-16

    We explore the deconvolution of the water-nitrate correlations by the first-order difference approach involving neutron diffraction of heavy- and null-aqueous solutions of KNO3 under 14N 15N and natON 18ON substitutions to achieve a full characterization of the first water coordination around the nitrate ion. For that purpose we performed isobaric-isothermal simulations of 3.5m KNO3 aqueous solutions at ambient conditions to generate the relevant radial distribution functions (RDF) required in the analysis (a) to identify the individual partial contributions to the total neutron weighted distribution function, (b) to isolate and assess the contribution of NO3 -!K+ pair formation, (c) to testmore » the accuracy of the NDIS-based coordination calculations and XRDbased assumptions, and (d) to describe the water coordination around both the nitrogen and oxygen sites of the nitrate ion.« less

  12. Excitation functions of deuteron induced reactions on natOs up to 50 MeV: Experiments and comparison with theoretical codes

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Adam Rebeles, R.; Tárkányi, F.; Takács, S.; Takács, M. P.; Ignatyuk, A.; Uddin, M. S.

    2013-02-01

    Activation of thin electrodeposited natural Os targets was investigated in a stacked foil irradiation with a 50 MeV deuteron beam. Assessments of the produced radionuclides by high resolution gamma spectroscopy yielded excitation functions for production of 184,185,186m1,g,187m1+g,188m1+g,189m2+m1+g,190m2,190m2,m1+g,192m1+gIr and 185Os. Reduced uncertainty on cross sections is obtained by simultaneous remeasurement of the 27Al(d,x)24Na monitor reaction over the whole energy range. Thick target yield for deuteron induced production route of 192m1+gIr and comparison with the natIr(n,γ) route are reviewed. A comparison with updated theoretical codes (ALICE-D, EMPIRE-D and the TENDL2011 on-line library) is discussed.

  13. Calculation of induced reactions of 3He-particles on natSb in 10-34MeV energy range.

    PubMed

    Gul, K

    2009-01-01

    Calculations for the excitation functions of the (121)Sb((3)He, xn) (121,122,123)I, and (123)Sb((3)He xn) (122,123,124,125)I reactions have been carried out using statistical and pre-equilibrium nuclear reaction models in 10-34MeV energy range. These excitation functions have been used to derive the excitation functions of the (nat)Sb((3)He, xn)(121,123,124)I reactions and compared with reported measurements. For studying the improvement with measurements two values of the diffuseness parameter a(w) equal to 0.9 and 0.7fm have been used in the calculations. The dependence of pre-equilibrium calculations on the initial exciton numbers has also been considered. PMID:18951811

  14. Dietary intake of vegetables and fruits and the modification effects of GSTM1 and NAT2 genotypes on bladder cancer risk.

    PubMed

    Lin, Jie; Kamat, Ashish; Gu, Jian; Chen, Meng; Dinney, Colin P; Forman, Michele R; Wu, Xifeng

    2009-07-01

    We analyzed the association between intakes of vegetables and fruits as defined by the U.S. Department of Agriculture pyramid food groups and bladder cancer risk using data collected in a large case-control study. The study included 884 histologically confirmed bladder cancer cases and 878 healthy controls matched to cases by age (+/-5 years), gender, and ethnicity. Significant inverse associations were observed for intakes of total vegetables, cruciferous vegetables, orange vegetables, dark green vegetables, and bladder cancer risk. Compared with those in the lowest quartile of total vegetable intake, the odds ratios for the 2nd, 3rd, and 4th quartiles of total vegetable intake were 0.84 [95% confidence interval (95% CI), 0.64-1.10], 0.71 (95% CI, 0.54-0.95), and 0.67 (95% CI, 0.50-0.90), respectively (P for trend = 0.004). Compared with those in the lowest quartile, those in the highest quartile of cruciferous vegetable intake had an odds ratio of 0.69 (95% CI, 0.52-0.92; P for trend = 0.001) and those in the highest quartile of orange vegetable intake had an odds ratio of 0.68 (95% CI, 0.52-0.91; P for trend = 0.006). Furthermore, the protective effect of cruciferous vegetables was more evident in subjects carrying GSTM1-null (odds ratio, 0.43; 95% CI, 0.25-0.73 for the 4th quartile of intake) and NAT2-slow genotypes (odds ratio, 0.56; 95% CI, 0.33-0.97 for the 4th quartile of intake). No association was observed for intakes of total fruits or citrus fruits. Our data strongly support that high vegetable consumption, especially cruciferous vegetable intake, may protect against bladder cancer and that genetic variants of GSTM1 and NAT2 may modify the association. PMID:19549811

  15. Acetylator genotype-dependent formation of 2-aminofluorene-hemoglobin adducts in rapid and slow acetylator Syrian hamsters congenic at the NAT2 locus.

    PubMed

    Feng, Y; Rustan, T D; Ferguson, R J; Doll, M A; Hein, D W

    1994-01-01

    Arylamine-hemoglobin adducts are a valuable dosimeter for assessing arylamine exposures and carcinogenic risk. The effects of age, sex, time-course, dose, and acetylator genotype on levels of 2-aminofluorene-hemoglobin adducts were investigated in homozygous rapid (Bio. 82.73/H-Patr) and slow (Bio. 82.73/H-Pats) acetylator hamsters congenic at the polymorphic (NAT2) acetylator locus. Following administration of a single ip dose of [3H]2-aminofluorene, peak 2-aminofluorene-hemoglobin adduct levels were achieved at 12-18 hr and retained a plateau up to 72 hr postinjection in both rapid and slow acetylator congenic hamsters. 2-Aminofluorene-hemoglobin adduct levels did not differ significantly between young (5-6 weeks) and old (32-49 weeks) hamsters or between male and female hamsters within either acetylator genotype. 2-Aminofluorene-hemoglobin adduct levels increased in a dose-dependent manner (r = 0.95, p = 0.0001) and were consistently higher in slow versus rapid acetylator congenic hamsters in studies of both time-course and dose-effect. The magnitude of the acetylator genotype-dependent difference was a function of dose; 2-aminofluorene-hemoglobin adduct levels were 1.5-fold higher in slow acetylator congenic hamsters following a 60 mg/kg 2-aminofluorene dose (p = 0.0013) but 2-fold higher following a 100 mg/kg 2-aminofluorene dose (p < 0.0001). These results show a specific and significant role for NAT2 acetylator genotype in formation of arylamine-hemoglobin adducts, which may reflect the relationship between acetylator genotype and the incidence of different cancers from arylamine exposures. PMID:8291051

  16. Yeast Kre33 and human NAT10 are conserved 18S rRNA cytosine acetyltransferases that modify tRNAs assisted by the adaptor Tan1/THUMPD1

    PubMed Central

    Sharma, Sunny; Langhendries, Jean-Louis; Watzinger, Peter; Kötter, Peter; Entian, Karl-Dieter; Lafontaine, Denis L.J.

    2015-01-01

    The function of RNA is subtly modulated by post-transcriptional modifications. Here, we report an important crosstalk in the covalent modification of two classes of RNAs. We demonstrate that yeast Kre33 and human NAT10 are RNA cytosine acetyltransferases with, surprisingly, specificity toward both 18S rRNA and tRNAs. tRNA acetylation requires the intervention of a specific and conserved adaptor: yeast Tan1/human THUMPD1. In budding and fission yeasts, and in human cells, we found two acetylated cytosines on 18S rRNA, one in helix 34 important for translation accuracy and another in helix 45 near the decoding site. Efficient 18S rRNA acetylation in helix 45 involves, in human cells, the vertebrate-specific box C/D snoRNA U13, which, we suggest, exposes the substrate cytosine to modification through Watson–Crick base pairing with 18S rRNA precursors during small subunit biogenesis. Finally, while Kre33 and NAT10 are essential for pre-rRNA processing reactions leading to 18S rRNA synthesis, we demonstrate that rRNA acetylation is dispensable to yeast cells growth. The inactivation of NAT10 was suggested to suppress nuclear morphological defects observed in laminopathic patient cells through loss of microtubules modification and cytoskeleton reorganization. We rather propose the effects of NAT10 on laminopathic cells are due to reduced ribosome biogenesis or function. PMID:25653167

  17. Yeast Kre33 and human NAT10 are conserved 18S rRNA cytosine acetyltransferases that modify tRNAs assisted by the adaptor Tan1/THUMPD1.

    PubMed

    Sharma, Sunny; Langhendries, Jean-Louis; Watzinger, Peter; Kötter, Peter; Entian, Karl-Dieter; Lafontaine, Denis L J

    2015-02-27

    The function of RNA is subtly modulated by post-transcriptional modifications. Here, we report an important crosstalk in the covalent modification of two classes of RNAs. We demonstrate that yeast Kre33 and human NAT10 are RNA cytosine acetyltransferases with, surprisingly, specificity toward both 18S rRNA and tRNAs. tRNA acetylation requires the intervention of a specific and conserved adaptor: yeast Tan1/human THUMPD1. In budding and fission yeasts, and in human cells, we found two acetylated cytosines on 18S rRNA, one in helix 34 important for translation accuracy and another in helix 45 near the decoding site. Efficient 18S rRNA acetylation in helix 45 involves, in human cells, the vertebrate-specific box C/D snoRNA U13, which, we suggest, exposes the substrate cytosine to modification through Watson-Crick base pairing with 18S rRNA precursors during small subunit biogenesis. Finally, while Kre33 and NAT10 are essential for pre-rRNA processing reactions leading to 18S rRNA synthesis, we demonstrate that rRNA acetylation is dispensable to yeast cells growth. The inactivation of NAT10 was suggested to suppress nuclear morphological defects observed in laminopathic patient cells through loss of microtubules modification and cytoskeleton reorganization. We rather propose the effects of NAT10 on laminopathic cells are due to reduced ribosome biogenesis or function. PMID:25653167

  18. Evaluation of the Whole-Blood Alere Q NAT Point-of-Care RNA Assay for HIV-1 Viral Load Monitoring in a Primary Health Care Setting in Mozambique.

    PubMed

    Jani, Ilesh V; Meggi, Bindiya; Vubil, Adolfo; Sitoe, Nádia E; Bhatt, Nilesh; Tobaiwa, Ocean; Quevedo, Jorge I; Loquiha, Osvaldo; Lehe, Jonathan D; Vojnov, Lara; Peter, Trevor F

    2016-08-01

    Viral load testing is the WHO-recommended monitoring assay for patients on HIV antiretroviral therapy (ART). Point-of-care (POC) assays may help improve access to viral load testing in resource-limited settings. We compared the performance of the Alere Q NAT POC viral load technology (Alere Technologies, Jena, Germany), measuring total HIV RNA using finger prick capillary whole-blood samples collected in a periurban health center, with that of a laboratory-based plasma RNA test (Roche Cobas Ampliprep/Cobas TaqMan v2) conducted on matched venous blood samples. The whole-blood Alere Q NAT POC assay produced results with a bias of 0.8593 log copy/ml compared to the laboratory-based plasma assay. However, at above 10,000 copies/ml, the bias was 0.07 log copy/ml. Using the WHO-recommended threshold to determine ART failure of 1,000 copies/ml, the sensitivity and specificity of the whole-blood Alere Q NAT POC assay were 96.83% and 47.80%, respectively. A cutoff of 10,000 copies/ml of whole blood with the Alere Q NAT POC assay appears to be a better predictor of ART failure threshold (1,000 copies/ml of plasma), with a sensitivity of 84.0% and specificity of 90.3%. The precision of the whole-blood Alere Q NAT POC assay was comparable to that observed with the laboratory technology (5.4% versus 7.5%) between detectable paired samples. HIV POC viral load testing is feasible at the primary health care level. Further research on the value of whole-blood viral load to monitor antiretroviral therapy is warranted. PMID:27252459

  19. N-Acetylation of p-aminobenzoic acid and p-phenylenediamine in primary porcine urinary bladder epithelial cells and in the human urothelial cell line 5637.

    PubMed

    Föllmann, Wolfram; Blaszkewicz, Meinolf; Behm, Claudia; Degen, Gisela H; Golka, Klaus

    2012-01-01

    N-Acetyltransferases (NAT) are important enzymes in the metabolism of certain carcinogenic arylamines, as N-acetylation decreases or prevents their bioactivation via N-hydroxylation. To study such processes in the bladder, cell culture models may be used, but metabolic competence needs to be characterized. This study focused on the N-acetylation capacity of two urothelial cell systems, using p-aminobenzoic acid (PABA) and the hair dye precursor p-phenylenediamine (PPD), two well-known substrates of the enzyme NAT1. The constitutive NAT1 activity was investigated using primary cultures of porcine urinary bladder epithelial cells (PUBEC) and in the human urothelial cell line 5637 to assess their suitability for further in vitro studies on PABA and PPD-induced toxicity. N-Acetylation of PABA and PPD was determined by high-performance liquid chromatography (HPLC) analysis in cytosols of the two cell systems upon incubation with various substrate levels for up to 60 min. The primary PUBEC revealed higher N-acetylation rates (2.5-fold for PABA, 5-fold for PPD) compared to the 5637 cell line, based on both PABA conversion to its acetylated metabolite and formation of mono- and diacetylated PPD. The urothelial cell systems may thus be useful as a tool for further studies on the N-acetylation of aromatic amines via NAT1. PMID:22994574

  20. Exceedingly Low Freezing Rates of Aqueous Hno3 and Hno3/h2so4 Droplets Under Polar Stratospheric Conditions

    NASA Astrophysics Data System (ADS)

    Knopf, D. A.; Koop, T.; Luo, B.; Weers, U. G.; Peter, T.

    In the Arctic winter 1999/2000 large particles containing nitric acid were observed during in situ field measurements. These large particles are important for the deni- trification of the Arctic stratosphere. It has been proposed that such particles form by homogeneous nucleation of nitric acid hydrates from liquid stratospheric aerosol droplets. Homogeneous nucleation rates of NAT (Nitric Acid Trihydrate) and NAD (Nitric Acid Dihydrate) have been determined in laboratory experiments for binary HNO3/H2O solutions only at supersaturations much larger than observed in the stratosphere. Therefore, an extrapolation of such laboratory data is required for the modelling of stratospheric particle formation and subsequent denitrification. We will present new laboratory data of homogeneous nucleation rates of NAT and NAD from droplets consisting of both binary HNO3/H2O as well as ternary HNO3/H2O/H2SO4 solutions. Optical microscopy has been used to deduce the droplet freezing tempera- tures. The nature of the crystallized solids was identified by Raman spectroscopy. The freezing data have been analyzed within the framework of classical nucleation theory. Our results are consistent with previously published laboratory aerosol data. However, for stratospheric conditions, we infer homogeneous nucleation rates to be lower by orders of magnitude than the extrapolation currently in use. We conclude that homo- geneous nucleation of NAT and NAD is not sufficient to explain the observed number concentrations of large nitric acid containing particles in the stratosphere.

  1. Role of signal-to-cut-off ratios of anti-hepatitis C virus antibody by enzyme immunoassays along with ID-NAT for screening of whole blood donors in India

    PubMed Central

    Arora, Satyam; Doda, Veena

    2016-01-01

    Background: The use of elevated signal-to-cut off ratios (S/CO) as an alternate to further supplemental testing (i.e., RIBA) has been included in the guidelines provided by the Centres for Disease Control and Prevention for HCV diagnostic purposes since 2003. With availability of screening by NAT and non availability of RIBA, further confirmation of HCV infection has been possible at the molecular level (RNA). Aims: To study the role of S/CO ratios of anti hepatitis C virus antibody detection by enzyme immunoassays (EIA) along with ID-NAT for screening of whole blood donors. Methods: In this study we reviewed the donor screening status for anti HCV from January 2013 to May 2014. All the donations were screened for anti HCV with fourth generation ELISA (BioRad Monolisa Ag-Ab Ultra) as well as with ID NAT (Procleix Ultrio). The S/CO ratio of all the anti-HCV reactive samples were analysed for their presence of HCV RNA. Results: On screening 21,115 donors for HCV, 83 donors (0.39%) were found reactive on pilot tube and repeat plasma bag testing (S/Co ratio ≥1) by ELISA. 41 donors were HCV RNA reactive with ID-NAT. 4 samples out of 41 were NAT yields and 37 were concordant reactive with ELISA. The S/Co ratio of anti-HCV reactive samples ranged from 0.9-11.1 [mean = 5.1; SD ± 2.9] whereas S/Co ratio of anti HCV and NAT reactive samples (concordant positives) ranged from 4.1-11.1 [mean 7.3]. In our analysis we found that S/CO ratio of 4 showed positive predictive value (PPV) and sensitivity of 100%. Summary/Conclusions: Our study showed that S/CO of 4 for anti HCV on ELISA would have maximum positive predictive value of having donor with HCV RNA. S/CO ratio of 4 is very close to 3.8 which was the CDC guideline. The presence of anti-HCV does not distinguish between current or past infections but a confirmed anti-HCV-positive result indicates the need for counseling and medical evaluation for HCV infection. PMID:27011676

  2. CYP1A2 and NAT2 phenotyping and 3-aminobiphenyl and 4-aminobiphenyl hemoglobin adduct levels in smokers and non-smokers

    SciTech Connect

    Sarkar, Mohamadi; Stabbert, Regina; Kinser, Robin D.; Oey, Jan; Rustemeier, Klaus; Holt, Klaus von; Schepers, Georg; Walk, Roger A.; Roethig, Hans J.

    2006-06-15

    Some aromatic amines are considered to be putative bladder carcinogens. Hemoglobin (Hb) adducts of 3-aminobiphenyl (3-ABP) and 4-aminobiphenyl (4-ABP) have been used as biomarkers of exposure to aromatic amines from cigarette smoke. One of the goals of this study was to determine intra- and inter-individual variability in 3-ABP and 4-ABP Hb adducts and to explore the predictability of ABP Hb adduct levels based on caffeine phenotyping. The study was conducted in adult smokers (S, n = 65) and non-smokers (NS, n 65). The subjects were phenotyped for CYP1A2 and NAT2 using urinary caffeine metabolites. Blood samples were collected twice within 6 weeks and adducts measured by GC/MS. The levels of 4-ABP Hb adducts were significantly (p < 0.0001) greater in S (34.5 {+-} 21.06 pg/g Hb) compared to NS (6.3 {+-} 3.02 pg/g Hb). The levels of 3-ABP Hb adducts were below the limit of quantification (BLOQ) in most (82%) of the NS and about 10-fold lower in S (3.6 {+-} 3.29 pg/g Hb) compared to 4-ABP Hb adducts. No differences were observed in the adduct levels between weeks 1 and 6 in the smokers, suggesting that a single sample would be adequate to monitor cigarette smoke exposure. The regression model developed with CYP1A2, NAT2 phenotype and number of cigarettes smoked (NCIG) accounted for 47% of the variability in 3-ABP adducts, whereas 32% variability in 4-ABP adducts was accounted by CYP1A2 and NCIG. The ratio of 4-ABP Hb adducts in adult S:NS was {approx} 5:1, whereas 3-ABP Hb adducts levels were BLOQ in some S, exhibited large interindividual variability ({approx} 91% compared to 57% for 4-ABP Hb) and poor dose response relationship. Therefore, 4-ABP Hb adduct levels may be a more useful biomarker of aminobiphenyl exposure from cigarette smoke.

  3. Morphology of nitric acid and water ice films

    NASA Technical Reports Server (NTRS)

    Keyser, Leon F.; Leu, Ming-Taun

    1993-01-01

    Ice films have been used to simulate stratospheric cloud surfaces in order to obtain laboratory data on solubilities and heterogeneous reaction rates. In the present study, environmental scanning electron microscopy (ESEM) is used to study thin films of both water ice and nitric acid ice near the composition of the trihydrate. The ices are formed by vapor deposition onto aluminum or borosilicate-glass substrates cooled to about 200 K. Micrographs are recorded during the deposition process and during subsequent annealing at higher temperatures. The results show that the ice films are composed of loosely consolidated granules, which range from about 1 to 20 microns in size at temperatures between 197 and 235 K. Cubic water ice is sometimes observed at 200 K, which converts to the hexagonal form at slightly higher temperatures. The loose packing of the granules confirms the high porosities of these films obtained from separate bulk porosity measurements. Average surface areas calculated from the observed granule sizes range from about 0.2 to 1 sq m/g and agree with surface areas obtained by gas-adsorption (BET) analysis of annealed ice films. For unannealed films, the BET areas are about an order of magnitude higher than the ESEM results, implying that the unannealed ices contain microporosity which is lost during the annealing process.

  4. Development of a Polar Stratospheric Cloud Model within the Community Earth System Model using constraints on Type I PSCs from the 2010-2011 Arctic winter

    NASA Astrophysics Data System (ADS)

    Zhu, Yunqian; Toon, Owen B.; Lambert, Alyn; Kinnison, Douglas E.; Brakebusch, Matthias; Bardeen, Charles G.; Mills, Michael J.; English, Jason M.

    2015-06-01

    Polar stratospheric clouds (PSCs) are critical elements of Arctic and Antarctic ozone depletion. We establish a PSC microphysics model using coupled chemistry, climate, and microphysics models driven by specific dynamics. We explore the microphysical formation and evolution of STS (Supercooled Ternary Solution) and NAT (Nitric Acid Trihydrate). Characteristics of STS particles dominated by thermodynamics compare well with observations. For example, the mass of STS is close to the thermodynamic equilibrium assumption when the particle surface area is >4 µm2/cm3. We derive a new nucleation rate equation for NAT based on observed denitrification in the 2010-2011 Arctic winter. The homogeneous nucleation scheme leads to supermicron NAT particles as observed. We also find that as the number density of NAT particles increases, the denitrification also increases. Simulations of the PSC lidar backscatter, denitrification, and gas phase species are generally within error bars of the observations. However, the simulations are very sensitive to temperature, which limits our ability to fully constrain some parameters (e.g., denitrification, ozone amount) based on observations.

  5. Nucleic acid-amplification testing for hepatitis B in cornea donors.

    PubMed

    Fornés, Maria Gema; Jiménez, Maria Angustias; Eisman, Marcela; Gómez Villagrán, Jose Luis; Villalba, Rafael

    2016-06-01

    Careful donor selection and implementation of tests of appropriate sensitivity and specificity are of paramount importance for minimizing the risk of transmitting infectious diseases from donors to corneal allograft recipients. Reported cases of viral transmission with corneal grafts are very unusual. Nevertheless potential virus transmission through the engraftment cannot be ruled out. According to European Guideline 2006/17/EC, screening for antibodies for Hepatitis B core antigen (anti HBc) is mandatory, and when this test is positive, some criteria must be established before using corneas. Despite the continuous progress in screening tests, donors carrying an occult hepatitis B infection (OBI) can cause transplant-transmitted hepatitis B. To date, Nucleic Acid Testing (NAT) is not an obligatory assay in corneal tissue setting neither in our country nor in the rest of European countries. Herein, we report three cornea donors that were rejected with the diagnosis of OBI through the testing of sensitive NAT and the serological profile of Hepatitis B virus. The aim of this report is to emphasize the need to include NAT in new reviews of EU Tissues and Cells Directives in order to increase level of security in tissue donation as well as not to reject a high number of donors with isolated profile of anti HBc in geographical areas with high prevalence of Hepatitis B, that could be rejected without a true criterion of Hepatitis B infection. PMID:26685699

  6. Pooled nucleic acid testing to identify antiretroviral treatment failure during HIV infection in Seoul, South Korea

    PubMed Central

    KIM, SUN BEAN; KIM, HYE WON; KIM, HYON-SUK; ANN, HEA WON; KIM, JAE KYOUNG; CHOI, HEUN; KIM, MIN HYUNG; SONG, JE EUN; AHN, JIN YOUNG; KU, NAM SU; OH, DONG HYUN; KIM, YONG CHAN; JEONG, SU JIN; HAN, SANG HOON; KIM, JUNE MYUNG; SMITH, DAVEY M.; CHOI, JUN YONG

    2013-01-01

    Background There have been various efforts to identify less costly but still accurate methods for monitoring the response to HIV treatment. We evaluated a pooling method to determine if this could improve screening efficiency and reduce costs while maintaining accuracy in Seoul, South Korea. Methods We conducted the first prospective study of pooled nucleic acid testing (NAT) using a 5 minipool + algorithm strategy versus individual viral load testing for patients receiving antiretroviral therapy (ART) between November 2011 and August 2012 at an urban hospital in Seoul, South Korea. The viral load assay used has a lower level of detection of 20 HIV RNA copies/ml, and the cost per assay is US$136. The 5 minipool + algorithm strategy was applied and 43 pooled samples were evaluated. The relative efficiency and accuracy of the pooled NAT were compared with those of individual testing. Results Using the individual viral load assay, 15 of 215 (7%) plasma samples had more than 200 HIV RNA copies/ml. The pooled NAT using the 5 minipool + algorithm strategy was applied to 43 pooled samples; 111 tests were needed to test all samples when virologic failure was defined at HIV RNA ≥ 200 copies/ml. Therefore, 104 tests were saved over individual testing, with a relative efficiency of 0.48. When evaluating costs, a total of US$ 14,144 was saved for 215 individual samples during 10 months. The negative predictive value was 99.5% for all samples with HIV RNA ≥ 200 copies/ml. Conclusions The pooled NAT with 5 minipool + algorithm strategy seems to be a very promising approach to effectively monitor patients receiving ART and to save resources. PMID:24228824

  7. Alpha particle induced reactions on natCr up to 39 MeV: Experimental cross-sections, comparison with theoretical calculations and thick target yields for medically relevant 52gFe production

    NASA Astrophysics Data System (ADS)

    Hermanne, A.; Adam Rebeles, R.; Tárkányi, F.; Takács, S.

    2015-08-01

    Thin natCr targets were obtained by electroplating, using 23.75 μm Cu foils as backings. In five stacked foil irradiations, followed by high resolution gamma spectroscopy, the cross sections for production of 52gFe, 49,51cumCr, 52cum,54,56cumMn and 48cumV in Cr and 61Cu,68Ga in Cu were measured up to 39 MeV incident α-particle energy. Reduced uncertainty is obtained by simultaneous remeasurement of the natCu(α,x)67,66Ga monitor reactions over the whole energy range. Comparisons with the scarce literature values and results from the TENDL-2013 on-line library, based on the theoretical code family TALYS-1.6, were made. A discussion of the production routes for 52gFe with achievable yields and contamination rates was made.

  8. NatB Domain-Containing CRA-1 Antagonizes Hydrolase ACER-1 Linking Acetyl-CoA Metabolism to the Initiation of Recombination during C. elegans Meiosis

    PubMed Central

    Gao, Jinmin; Kim, Hyun-Min; Elia, Andrew E.; Elledge, Stephen J.; Colaiácovo, Monica P.

    2015-01-01

    The formation of DNA double-strand breaks (DSBs) must take place during meiosis to ensure the formation of crossovers, which are required for accurate chromosome segregation, therefore avoiding aneuploidy. However, DSB formation must be tightly regulated to maintain genomic integrity. How this regulation operates in the context of different chromatin architectures and accessibility, and how it is linked to metabolic pathways, is not understood. We show here that global histone acetylation levels undergo changes throughout meiotic progression. Moreover, perturbations to global histone acetylation levels are accompanied by changes in the frequency of DSB formation in C. elegans. We provide evidence that the regulation of histone acetylation requires CRA-1, a NatB domain-containing protein homologous to human NAA25, which controls the levels of acetyl-Coenzyme A (acetyl-CoA) by antagonizing ACER-1, a previously unknown and conserved acetyl-CoA hydrolase. CRA-1 is in turn negatively regulated by XND-1, an AT-hook containing protein. We propose that this newly defined protein network links acetyl-CoA metabolism to meiotic DSB formation via modulation of global histone acetylation. PMID:25768301

  9. Production of (28)Mg by bombardment of (nat)Cl with 200MeV protons: Proof-of-concept study for a stacked LiCl target.

    PubMed

    van der Meulen, N P; Steyn, G F; Vermeulen, C; van Rooyen, T J

    2016-09-01

    A stacked target consisting of ten Al-encapsulated LiCl discs, for producing (28)Mg via the (nat)Cl(p,X)(28)Mg process in the energy region 50-200MeV, is described. This target was irradiated with a 200MeV beam at an intensity of 100nA, providing information on both yield and outscattering losses. Results of a Monte Carlo modelling of the beam and target, by means of the code MCNPX, are also presented. Similar Al-encapsulated LiCl discs were individually irradiated with 66MeV proton beams of 65 and 90μA, respectively, to study their behaviour under high-intensity bombardment. Once removed from the Al encapsulation, the (28)Mg can be separated from the LiCl target material efficiently, using a 12.5cm x 1cm(2) column containing Purolite S950 chelating resin. The eluate contains (7)Be but no other measurable radio-contaminants. The removal of the (7)Be contaminant is performed by cation exchange chromatography in malate media, with (28)Mg being retained by the resin and (7)Be eluted. PMID:27372806

  10. Projectile-like fragments from {sup 129}Xe+{sup nat}Cu reactions at E/A = 40 MeV

    SciTech Connect

    Russ, D.E.; Mignerey, A.C.; Garcia-Solis, E.J.

    1996-02-01

    The bombarding of heavy nuclei with energetic heavy projectiles has been one of the most important experimental tools for nuclear science. At low beam energies, (E/A) beam <10 MeV, the reactions appear to be dominated by mean field consideration. At higher beam energies, (E/A) beams > 100 MeV, these mean field effects are less important and nucleon-nucleon interactions dominate. Within the intermediate energy region, the situation is less clear because of both the mean field and nucleon-nucleon effects contribute. There is no consensus on the theoretical treatment of nuclear reaction in the intermediate energy regime and statistical, dynamical, and hybrid models have been used with limited success. Previous studies of {sup 136}Xe + {sup 209}Bi at E/A = 28 MeV carried out at Michigan State University (MSU) have been well described by a damped reaction mechanism. On the other hand, {sup 129}Xe + {sup nat}Cu at E/A = 50 MeV also at MSU has been compared with a hybrid model with reasonable success. In order to see a transition from a damped reaction mechanism to more fragmentation-like processes, an experiment was carried out at MSU using {sup 129}Xe beams at E/A = 30, 40, 50, and 60 MeV. The targets were Cu, Sc, and Au. The current study only looks at the projectile-like fragments (PLF) detected in the Maryland Forward Array (MFA).

  11. The effect of chronic morphine or methadone exposure and withdrawal on clock gene expression in the rat suprachiasmatic nucleus and AA-NAT activity in the pineal gland.

    PubMed

    Pačesová, D; Novotný, J; Bendová, Z

    2016-07-18

    The circadian rhythms of many behavioral and physiological functions are regulated by the major circadian pacemaker in the suprachiasmatic nucleus. Long-term opiate addiction and drug withdrawal may affect circadian rhythmicity of various hormones or the sleep/activity pattern of many experimental subjects; however, limited research has been done on the long-term effects of sustained opiate administration on the intrinsic rhythmicity in the suprachiasmatic nucleus and pineal gland. Here we compared the effects of repeated daily treatment of rats with morphine or methadone and subsequent naloxone-precipitated withdrawal on the expression of the Per1, Per2, and Avp mRNAs in the suprachiasmatic nucleus and on arylalkylamine N-acetyltransferase activity in the pineal gland. We revealed that 10-day administration and withdrawal of both these drugs failed to affect clock genes and Avp expression in the SCN. Our results indicate that opioid-induced changes in behavioral and physiological rhythms originate in brain structures downstream of the suprachiasmatic nucleus regulatory output pathway. Furthermore, we observed that acute withdrawal from methadone markedly extended the period of high night AA-NAT activity in the pineal gland. This suggests that withdrawal from methadone, a widely used drug for the treatment of opioid dependence, may have stronger impact on melatonin synthesis than withdrawal from morphine. PMID:27070740

  12. Photo-neutron reaction cross-sections for natMo in the bremsstrahlung end-point energies of 12-16 and 45-70 MeV

    NASA Astrophysics Data System (ADS)

    Naik, H.; Kim, G. N.; Kapote Noy, R.; Schwengner, R.; Kim, K.; Zaman, M.; Shin, S. G.; Gey, Y.; Massarczyk, R.; John, R.; Junghans, A.; Wagner, A.; Cho, M.-H.

    2016-07-01

    The natMo( γ, xn)90, 91, 99Mo reaction cross-sections were experimentally determined for the bremsstrahlung end-point energies of 12, 14, 16, 45, 50, 55, 60 and 70MeV by activation and off-line γ -ray spectrometric technique and using the 20MeV electron linac (ELBE) at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany, and the 100MeV electron linac at the Pohang Accelerator Laboratory (PAL), Pohang, Korea. The natMo( γ, xn)88, 89, 90, 91, 99Mo reaction cross-sections as a function of photon energy were also calculated using the computer code TALYS 1.6. The flux-weighted average cross-sections were obtained from the literature data and the calculated values of TALYS based on mono-energetic photons and are found to be in general agreement with the present results. The flux-weighted average experimental and theoretical cross-sections for the natMo( γ, xn)88, 89, 90, 91, 99Mo reactions increase with the bremsstrahlung end-point energy, which indicates the role of excitation energy. After a certain energy, the individual natMo( γ, xn) reaction cross-sections decrease with the increase of bremsstrahlung energy due to opening of other reactions, which indicates sharing of energy in different reaction channels. The 100Mo( γ, n) reaction cross-section is important for the production of 99Mo , which is a probable alternative to the 98Mo(n, γ) and 235U(n, f ) reactions.

  13. NF-κB Drives the Synthesis of Melatonin in RAW 264.7 Macrophages by Inducing the Transcription of the Arylalkylamine-N-Acetyltransferase (AA-NAT) Gene

    PubMed Central

    Muxel, Sandra Marcia; Pires-Lapa, Marco Antonio; Monteiro, Alex Willian Arantes; Cecon, Erika; Tamura, Eduardo Koji; Floeter-Winter, Lucile Maria; Markus, Regina P.

    2012-01-01

    We demonstrate that during inflammatory responses the nuclear factor kappa B (NF-κB) induces the synthesis of melatonin by macrophages and that macrophage-synthesized melatonin modulates the function of these professional phagocytes in an autocrine manner. Expression of a DsRed2 fluorescent reporter driven by regions of the aa-nat promoter, that encodes the key enzyme involved in melatonin synthesis (arylalkylamine-N-acetyltransferase), containing one or two upstream κB binding sites in RAW 264.7 macrophage cell lines was repressed when NF-κB activity was inhibited by blocking its nuclear translocation or its DNA binding activity or by silencing the transcription of the RelA or c-Rel NF-κB subunits. Therefore, transcription of aa-nat driven by NF-κB dimers containing RelA or c-Rel subunits mediates pathogen-associated molecular patterns (PAMPs) or pro-inflammatory cytokine-induced melatonin synthesis in macrophages. Furthermore, melatonin acts in an autocrine manner to potentiate macrophage phagocytic activity, whereas luzindole, a competitive antagonist of melatonin receptors, decreases macrophage phagocytic activity. The opposing functions of NF-κB in the modulation of AA-NAT expression in pinealocytes and macrophages may represent the key mechanism for the switch in the source of melatonin from the pineal gland to immune-competent cells during the development of an inflammatory response. PMID:23284853

  14. 4{pi} studies of the 1.8{endash}4.8 GeV {sup 3}He+{sup nat}Ag, {sup 197}Au reactions. I. Energy deposition

    SciTech Connect

    Morley, K.B.; Kwiatkowski, K.; Bracken, D.S.; Renshaw Foxford, E.; Viola, V.E.; Woo, L.W.; Yoder, N.R.; Legrain, R.; Pollacco, E.C.; Volant, C.; Korteling, R.G.; Breuer, H.; Brzychczyk, J.

    1996-08-01

    The Indiana Silicon Sphere 4{pi} detector has been used to measure light-charged particles and intermediate-mass fragments (IMFs) emitted in the 18{endash}4.8 GeV {sup 3}He+{sup nat}Ag, {sup 197}Au reactions. Ejectile multiplicity and total event kinetic energy distributions scale systematically with projectile energy and target mass, except for the {sup nat}Ag target at 3.6 and 4.8 GeV. For this system, a saturation in deposition energy is indicated by the data, suggesting the upper projectile energy for stopping has been reached. Maximum deposition energies of {approximately}950 MeV for the {sup nat}Ag target and {approximately}1600 MeV for the {sup 197}Au target are inferred from the data. The results also demonstrate the importance of accounting for fast cascade processes in defining the excitation energy of the targetlike residue. Correlations between various observables and the average IMF multiplicity indicate that the total thermal energy and total observed charge provide useful gauges of the excitation energy of the fragmenting system. Comparison of the experimental distributions with intranuclear cascade predictions shows qualitative agreement. {copyright} {ital 1996 The American Physical Society.}

  15. 2-(2-Pyrid­yl)pyridinium bis­(pyridine-2,6-dicarboxyl­ato-κ3 O,N,O′)aluminate(III) trihydrate

    PubMed Central

    Soleimannejad, Janet; Aghabozorg, Hossein; Mohammadzadeh, Yaghoub; Hooshmand, Shabnam

    2008-01-01

    The title compound, (C10H9N2)[Al(C7H3NO4)2]·3H2O or (2,2′-bipyH)[Al(pydc)2]·3H2O (where 2,2′-bipy is 2,2′-bipyridine and pydcH2 is pyridine-2,6-dicarboxylic acid), was synthesized by the reaction of aluminium(III) nitrate nona­hydrate with pyridine-2,6-dicarboxylic acid and 2,2′-bipyridine in a 1:2:4 molar ratio in aqueous solution. This compound is composed of an anionic complex, [Al(pydc)2]−, a protonated 2,2′-bipyridine mol­ecule as a counter-ion, (2,2′-bipyH)+, and three uncoordinated water mol­ecules. The anion is a six-coordinate complex, with the AlIII atom in a distorted octa­hedral geometry coordinated by two tridentate pyridine-2,6-dicarboxyl­ate groups. In the crystal structure, inter­molecular O—H⋯O, N—H⋯O, N—H⋯N and C—H⋯O hydrogen bonds, π–π stacking between two aromatic rings [centroid–centroid distance = 3.827 (10) Å], and C=O⋯π stacking [with distances of 3.2311 (13), 3.4924 (14) and 3.5731 (13) Å], connect the various components to form a supra­molecular structure. PMID:21202744

  16. Observational Evidence Against Mountain-Wave Generation of Ice Nuclei as a Prerequisite for the Formation of Three Solid Nitric Acid Polar Stratospheric Clouds Observed in the Arctic in Early December 1999

    NASA Technical Reports Server (NTRS)

    Pagan, Kathy L.; Tabazadeh, Azadeh; Drdla, Katja; Hervig, Mark E.; Eckermann, Stephen D.; Browell, Edward V.; Legg, Marion J.; Foschi, Patricia G.

    2004-01-01

    A number of recently published papers suggest that mountain-wave activity in the stratosphere, producing ice particles when temperatures drop below the ice frost point, may be the primary source of large NAT particles. In this paper we use measurements from the Advanced Very High Resolution Radiometer (AVHRR) instruments on board the National Oceanic and Atmospheric Administration (NOAA) polar-orbiting satellites to map out regions of ice clouds produced by stratospheric mountain-wave activity inside the Arctic vortex. Lidar observations from three DC-8 flights in early December 1999 show the presence of solid nitric acid (Type Ia or NAT) polar stratospheric clouds (PSCs). By using back trajectories and superimposing the position maps on the AVHRR cloud imagery products, we show that these observed NAT clouds could not have originated at locations of high-amplitude mountain-wave activity. We also show that mountain-wave PSC climatology data and Mountain Wave Forecast Model 2.0 (MWFM-2) raw hemispheric ray and grid box averaged hemispheric wave temperature amplitude hindcast data from the same time period are in agreement with the AVHRR data. Our results show that ice cloud formation in mountain waves cannot explain how at least three large scale NAT clouds were formed in the stratosphere in early December 1999.

  17. A case of type I polar stratospheric cloud formation by heterogeneous nucleation

    NASA Technical Reports Server (NTRS)

    Pueschel, R. F.; Ferry, G. V.; Snetsinger, K. G.; Goodman, J.; Dye, J. E.; Baumgardner, D.; Gandrud, B. W.

    1992-01-01

    The NASA ER-2 aircraft flew on January 24, 1989, from Stavanger to Spitsbergen, Norway, at the 430-440 K potential temperature surface (19.2-19.8 km pressure altitude). Aerosols were sampled continuously by an optical particle counter (PMS-FSSP300) for concentration and size analyses, and during five 10-min intervals by four wire and one replicator impactor for concentration, size, composition, and phase analysis. During sampling, the air saturation of H2O with respect to ice changed from 20 to 100 percent, and of HNO3 with respect to nitric acid trihydrate (NAT) from subsaturation to supersaturation. Data from both instruments indicate a condensation of hydrochloric acid and, later, nitric acid on the background aerosol particles as the ambient temperature decreases along the flight track. This heterogeneous nucleation mechanism generates type I polar stratospheric cloud particles of 10-fold enhanced optical depth, which could play a role in stratospheric ozone depletion.

  18. How do Polar Stratospheric Clouds Form?

    NASA Technical Reports Server (NTRS)

    Drdla, Katja; Gandrud, Bruce; Baumgardner, Darrel; Herman, Robert; Gore, Warren J. (Technical Monitor)

    2000-01-01

    SOLVE measurements have been compared with results from a microphysical model to understand the composition and formation of the polar stratospheric clouds (PSCs) observed during SOLVE. Evidence that the majority of the particles remain liquid throughout the winter will be presented. However, a small fraction of the particles do freeze, and the presence of these frozen particles can not be explained by current theories, in which the only freezing mechanism is homogeneous freezing to ice below the ice frost point. Alternative formation mechanisms, in particular homogeneous freezing above the ice frost point and heterogeneous freezing, have been explored using the microphysical model. Both nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD) have been considered as possible compositions for the solid-phase nitric acid aerosols. Comparisons between the model results and the SOLVE measurements will be used to constrain the possible formation mechanisms. Other effects of these frozen particles will also be discussed, in particular denitrification.

  19. A physical adsorption model of the dependence of ClONO2 heterogeneous reactions on relative humidity

    NASA Astrophysics Data System (ADS)

    Henson, Bryan F.; Wilson, Kevin R.; Robinson, Jeanne M.

    We present a model of heterogeneous reactivity based on physical adsorption that describes the observed relative humidity dependence of the ClONO2 reaction probability with H2O and HCl on sulfuric acid tetrahydrate ice surfaces (SAT) and with H2O on nitric acid trihydrate (NAT). The laboratory data are modeled using only two parameters for a given system, the measured reaction probability on a neat H2O ice surface, and a constant from the BET theory which describes the fraction of an acid hydrate surface covered by H2O as a function of relative humidity. The model indicates that ClONO2 reactivity with both HCl and H2O on SAT and with H2 O on NAT is controlled by the surface coverage of H2O. In contrast, the reaction of ClONO2 +HCl on NAT is better described by an alternative model based on reactivity in solutions formed within a porous ice by capillary liquid absorption.

  20. Amino acids

    MedlinePlus

    Amino acids are organic compounds that combine to form proteins . Amino acids and proteins are the building blocks of life. When proteins are digested or broken down, amino acids are left. The human body uses amino acids ...

  1. Condensed-Phase Nitric Acid in a Tropical Subvisible Cirrus Cloud

    NASA Technical Reports Server (NTRS)

    Popp, P. J.; Marcy, T. P.; Watts, O. A.; Gao, R. S.; Fahey, D. W.; Weinstock, E. M.; Smith, J. B.; Herman, R. L.; Tropy, R. F.; Webster, C. r.; Christensen, L. E.; Baumgardner, D. G.; Voigt, C.; Kaercher, B.; Wilson, J. C.; Mahoney, M. J.; Jensen, E. J.; Bui, T. P.

    2007-01-01

    In situ observations in a tropical subvisible cirrus cloud during the Costa Rica Aura Validation Experiment on 2 February 2006 show the presence of condensed-phase nitric acid. The cloud was observed near the tropopause at altitudes of 16.3-17.7 km in an extremely cold (183-191 K) and dry 5 ppm H2O) air mass. Relative humidities with respect to ice ranged from 150-250% throughout most of the cloud. Optical particle measurements indicate the presence of ice crystals as large as 90 microns in diameter. Condensed RN031H20 molar ratios observed in the cloud particles were 1-2 orders of magnitude greater than ratios observed previously in cirrus clouds at similar RN03 partial pressures. Nitric acid trihydrate saturation ratios were 10 or greater during much of the cloud encounter, indicating that RN03 may be present in the cloud particles as a stable condensate and not simply physically adsorbed on or trapped in the particles.

  2. Laboratory Studies of Model Stratospheric Aerosol Films Using Fourier Transform Infrared Spectroscopy.

    NASA Astrophysics Data System (ADS)

    Middlebrook, Ann Marie

    Heterogeneous chemistry plays an important role in the balance of stratospheric ozone. Although the chemical composition and phase of stratospheric aerosols affect their heterogeneous reactivity, these quantities have not been firmly established. Stratospheric sulfate aerosols (SSAs), found globally, are composed of mixtures of sulfuric acid and water. Type I polar stratospheric clouds (PSCs) composed of nitric acid and water can form when temperatures drop to {~}193 K, whereas Type II PSCs composed of pure ice form at or below the ice frost point ({~}189 K). This thesis focuses on using Fourier transform infrared (FTIR) spectroscopy to determine the likely composition and phase of stratospheric particles by examining thin nitric-acid/ice and sulfuric-acid/water films representative of polar and global stratospheric aerosols, respectively. First, we measured the composition of FTIR-characterized nitric-acid/ice films using mass spectrometry. Results confirmed the infrared assignments of nitric acid monohydrate (NAM), dihydrate (NAD), and amorphous HNO_3 /H_2O films. We also observed two infrared spectra for nitric acid trihydrate ( alpha- and beta-NAT). Using optical interference measurements at lambda = 632 nm, we obtained the real refractive indices for amorphous H_2O/HNO_3 (from 1.31 for dilute HNO_3 to 1.49 for pure HNO_3), NAM (1.53), alpha-NAT (1.51), beta -NAT (>=1.46), and ice (1.30) films. We then performed cooling experiments to determine which nitric-acid/ice might form in the stratosphere. Under stratospheric water and nitric acid partial pressures, either amorphous 3:1 H_2O:HNO _3 or beta-NAT films formed at temperatures above the ice frost point. Other experiments indicated that beta-NAT is the most stable nitric acid hydrate under stratospheric conditions. Thus we believe that Type I PSCs are composed of beta-NAT crystals. To mimic phase changes of SSAs, we subjected liquid sulfuric acid films to temperature cycles in the presence of water. While

  3. Polar stratospheric clouds in the 1998-2003 Antarctic vortex: Microphysical modeling and Polar Ozone and Aerosol Measurement (POAM) III observations

    NASA Astrophysics Data System (ADS)

    Benson, C. M.; Drdla, K.; Nedoluha, G. E.; Shettle, E. P.; Alfred, J.; Hoppel, K. W.

    2006-09-01

    The Integrated Microphysics and Aerosol Chemistry on Trajectories (IMPACT) model is used to study polar stratospheric cloud (PSC) formation and evolution in the Antarctic vortex. The model is applied to individual air parcel trajectories driven by UK Met Office (UKMO) wind and temperature fields. The IMPACT model calculates the parcel microphysics, including the formation and sedimentation of ice, nitric acid trihydrate (NAT), sulfuric acid tetrahydrate (SAT), and supercooled ternary solution (STS) aerosols. Model results are validated by comparison with data obtained by the Polar Ozone and Aerosol Measurement (POAM) III solar occultation instrument and are examined for 6 years of POAM data (1998-2003). Comparisons of POAM water vapor and aerosol extinction measurements to the model results help to constrain three microphysical parameters influencing the formation and growth of both type I and type II PSCs. Principally, measurements of aerosol extinction prove to be valuable in differentiating model runs; the relationship of aerosol extinction to temperature is determined by the various particle types as they form and grow. Comparison of IMPACT calculations of this relationship to POAM measurements suggests that the initial fraction of nuclei available for heterogeneous NAT freezing is approximately 0.02% of all aerosols. Constraints are also placed on the accommodation coefficient of ice and the NAT-ice lattice compatibility. However, these two parameters have similar effects on the extinction-temperature relationship, and thus a range of values are permissible for each.

  4. Homogenous Surface Nucleation of Solid Polar Stratospheric Cloud Particles

    NASA Technical Reports Server (NTRS)

    Tabazadeh, A.; Hamill, P.; Salcedo, D.; Gore, Warren J. (Technical Monitor)

    2002-01-01

    A general surface nucleation rate theory is presented for the homogeneous freezing of crystalline germs on the surfaces of aqueous particles. While nucleation rates in a standard classical homogeneous freezing rate theory scale with volume, the rates in a surface-based theory scale with surface area. The theory is used to convert volume-based information on laboratory freezing rates (in units of cu cm, seconds) of nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD) aerosols into surface-based values (in units of sq cm, seconds). We show that a surface-based model is capable of reproducing measured nucleation rates of NAT and NAD aerosols from concentrated aqueous HNO3 solutions in the temperature range of 165 to 205 K. Laboratory measured nucleation rates are used to derive free energies for NAT and NAD germ formation in the stratosphere. NAD germ free energies range from about 23 to 26 kcal mole, allowing for fast and efficient homogeneous NAD particle production in the stratosphere. However, NAT germ formation energies are large (greater than 26 kcal mole) enough to prevent efficient NAT particle production in the stratosphere. We show that the atmospheric NAD particle production rates based on the surface rate theory are roughly 2 orders of magnitude larger than those obtained from a standard volume-based rate theory. Atmospheric volume and surface production of NAD particles will nearly cease in the stratosphere when denitrification in the air exceeds 40 and 78%, respectively. We show that a surface-based (volume-based) homogeneous freezing rate theory gives particle production rates, which are (not) consistent with both laboratory and atmospheric data on the nucleation of solid polar stratospheric cloud particles.

  5. Uncertainties in reactive uptake coefficients for solid stratospheric particles—2. Effect on ozone depletion

    NASA Astrophysics Data System (ADS)

    Carslaw, Kenneth S.; Peter, Thomas; Müller, Rolf

    Uncertainties in reactive uptake coefficients for reactions involving HCl, ClONO2 and HOCl on nitric acid trihydrate (NAT) and sulfuric acid tetrahydrate (SAT) are shown to affect modeled Arctic stratospheric ozone depletion in a photochemical box model. The main contribution to the difference arises from the reaction ClONO2 + HCl → Cl2 + HNO3 in early to mid-winter. During this period, differences in predicted HCl and ClONO2 are more than 1 ppbv for several weeks when an upper limit for solid PSC existence is assumed. Ozone depletion is greater when liquid aerosols persist through the winter compared with cases where solid particles are assumed to form.

  6. Nuclear model analysis of excitation functions of proton induced reactions on ⁸⁶Sr, ⁸⁸Sr and natZr: Evaluation of production routes of ⁸⁶Y.

    PubMed

    Zaneb, H; Hussain, M; Amjed, N; Qaim, S M

    2015-10-01

    The proton induced nuclear reactions on (86)Sr, (88)Sr and (nat)Zr were investigated for the production of (86)Y. The literature data were compared with the results of nuclear model calculations using the codes ALICE-IPPE, TALYS 1.6 and EMPIRE 3.2. The thick target yields of (86)Y were calculated from the recommended excitation functions. Analysis of radioyttrium impurities was also performed. A comparison of the various production routes showed that for medical applications of (86)Y, the reaction (86)Sr(p,n)(86)Y is the method of choice, which gives efficient yield with minimum impurities. PMID:26210800

  7. Measurement and simulation of the cross sections for the production of {sup 148}Gd in thin {sup nat}W and {sup 181}Ta targets irradiated with 0.4- to 2.6-GeV protons

    SciTech Connect

    Titarenko, Yu. E. Batyaev, V. F.; Titarenko, A. Yu.; Butko, M. A.; Pavlov, K. V.; Florya, S. N.; Tikhonov, R. S.; Zhivun, V. M.; Ignatyuk, A. V.; Mashnik, S. G.; Leray, S.; Boudard, A.; Cugnon, J.; Mancusi, D.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Mank, G.; Gudowski, W.

    2011-04-15

    The cross sections for the production of {sup 148}Gd in {sup nat}W and {sup 181}Ta targets irradiated by 0.4-, 0.6-, 0.8-, 1.2-, 1.6-, and 2.6-GeV protons at the ITEP accelerator complex have been measured by direct {alpha} spectrometry without chemical separation. The experimental data have been compared with the data obtained at other laboratories and with the theoretical simulations of the yields on the basis of the BERTINI, ISABEL, CEM03.02, INCL4.2, INCL4.5, CASCADE07, and PHITS codes.

  8. Hydration effect on proton transfer in melamine-cyanuric acid complex.

    PubMed

    Yan, Shihai; Kang, Baotao; Lee, Jin Yong; Sun, Lixiang

    2016-07-01

    Self-assembly of melamine-cyanuric acid (MC) leads to urinary tract calculi and renal failure. The hydration effects on molecular geometry, the IR spectra, the frontier molecular orbital, the energy barrier of proton transfer (PT), as well as the stability of MC were explored by density functional theory (DFT) calculations. The intramolecular PT breaks the big π-conjugated ring of melamine or converts the p-π conjugation (:N-C'=O) to π-π conjugation (O=C-N=C') of cyanuric acid. The intermolecular PT varies the coupling between melamine and cyanuric acid from pure hydrogen bonds (Na…HNd and NH…O) to the cooperation of cation…anion electrostatic interaction (NaH(+)…Nd (-)) and two NH…O hydrogen bonds. Distinct IR spectra shifts occur for Na…HNd stretching mode upon PT, i.e., blue-shift upon intramolecular PT and red-shift upon intermolecular PT. It is expected that the PT would inhibit the generation of rosette-like structure or one-dimensional tape conformer for the MC complexes. Hydration obviously effects the local geometric structure around the water binding site, as well as the IR spectra of NH…O and N…HN hydrogen bonds. Hydration decreases the intramolecular PT barrier from ~45 kcal mol(-1) in anhydrous complex to ~11.5 kcal mol(-1) in trihydrated clusters. While, the hydration effects on intermolecular PT barrier is slight. The relative stability of MC varies slightly by hydration due to the strong hydrogen bond interaction between melamine and cyanuric acid fragments. Graphical Abstract Hydration effect on proton transfer in melamine-cyanuric acid complex. PMID:27351422

  9. Identification and characterization of an amino acid transporter expressed differentially in liver

    PubMed Central

    Gu, Sumin; Roderick, Hywel Llewelyn; Camacho, Patricia; Jiang, Jean X.

    2000-01-01

    Cellular metabolic needs are fulfilled by transport of amino acids across the plasma membrane by means of specialized transporter proteins. Although many of the classical amino acid transporters have been characterized functionally, less than half of these proteins have been cloned. In this report, we identify and characterize a cDNA encoding a plasma membrane amino acid transporter. The deduced amino acid sequence is 505 residues and is highly hydrophobic with the likely predicted structure of 9 transmembrane domains, which putatively place the amino terminus in the cytoplasm and the carboxy terminus on the cell surface. Expression of the cRNA in Xenopus laevis oocytes revealed strong transport activities specific for histidine and glutamine. This protein is a Na+- and pH-dependent transporter and tolerates substitution of Na+ by Li+. Furthermore, this transporter is not an obligatory exchanger because efflux occurs in the absence of influx. This transporter is expressed predominantly in the liver, although it is also present in the kidney, brain, and heart. In the liver, it is located in the plasma membrane of hepatocytes, and the strongest expression was detected in those adjacent to the central vein, gradually decreasing towards the portal tract. Because this protein displays functional similarities to the N-system amino acid transport, we have termed it mNAT, for murine N-system amino acid transporter. This is the first transporter gene identified within the N-system, one of the major amino acid transport systems in the body. The expression pattern displayed by mNAT suggests a potential role in hepatocyte physiology. PMID:10716701

  10. Folic Acid

    MedlinePlus

    Folic acid is a B vitamin. It helps the body make healthy new cells. Everyone needs folic acid. For women who may get pregnant, it is really important. Getting enough folic acid before and during pregnancy can prevent major birth ...

  11. Folic Acid

    MedlinePlus

    Folic acid is used to treat or prevent folic acid deficiency. It is a B-complex vitamin needed by ... Folic acid comes in tablets. It usually is taken once a day. Follow the directions on your prescription label ...

  12. Aspartic acid

    MedlinePlus

    ... also called asparaginic acid. Aspartic acid helps every cell in the body work. It plays a role in: Hormone production and release Normal nervous system function Plant sources of aspartic acid include: Legumes such as ...

  13. Diaqua-tetra-bromidotin(IV) trihydrate.

    PubMed

    Ye, Fei; Reuter, Hans

    2012-09-01

    The title compound, [SnBr(4)(H(2)O)(2)]·3H(2)O, forms large colourless crystals in originally sealed samples of tin tetra-bromide. It constitutes the first structurally characterized hydrate of SnBr(4) and is isostructural with the corresponding -hydrate of SnCl(4). It is composed of Sn(IV) atoms octa-hedrally coordinated by four Br atoms and two cis-related water mol-ecules. The octa-hedra exhibit site symmetry 2. They are arranged into columns along [001] via medium-strong O-H⋯O hydrogen bonds involving the two lattice water mol-ecules (one situated on a twofold rotation axis) while the chains are inter-connected via longer O-H⋯Br hydrogen bonds, forming a three-dimensional network. PMID:22969439

  14. Measurements of 67Ga production cross section induced by protons on natZn in the low energy range from 1.678 to 2.444 MeV

    NASA Astrophysics Data System (ADS)

    Wachter, J. A.; Miranda, P. A.; Morales, J. R.; Cancino, S. A.; Correa, R.

    2015-02-01

    The experimental production cross section for the reaction natZn(p,x)67Ga has been measured in the energy range from 1.678 to 2.444 MeV. The methodology used in this work is based on characteristic X-ray emitted after irradiation by the daughter nuclei that decays by electron capture (EC) and the use of a complementary PIXE experiment. By doing so, expressions needed to determine cross section values are simplified since experimental factors such as geometric setup and an detector efficiency are avoided. 67Ga is a radionuclide particularly suited for this method since it decays by electron capture in 100% and the subsequent characteristic X-ray emission is easily detected. Natural zinc targets were fabricated by PVD technique and afterwards their thicknesses were determined by Rutherford Backscattering Spectrometry. Cross sections measurements were carried out by using the Van de Graaff accelerator located at Faculty of Sciences, University of Chile. It was found that our data for the natZn(p,x)67Ga reaction are, in general, in good agreement when compared to existing experimental data and to those calculated ALICE/ASH nuclear code. On the other hand, values predicted by Talys-1.6 are showing systematically lower magnitudes than our measured data.

  15. Measurement of Isomeric Yield Ratio of 143m,gSm from natSm(γ,xn) Reaction with End-Point Bremsstrahlung Energies of 40-60 MeV

    NASA Astrophysics Data System (ADS)

    Yang, S. C.; Kim, K.; Kim, G. N.; Kim, H. I.; Lee, Y. O.; Lee, M. W.; Pham, D. K.; Nguyen, V. D.; Shin, S. G.; Cho, M. H.

    2014-05-01

    The isomeric yield ratios (IR) of 143m,gSm from the natSm(γ, xn) reaction with the end-point bremsstrahlung energies of 40, 50 and 60 MeV were measured by the activation method and using the 100 MeV electron linac of the Pohang Accelerator Laboratory (PAL), Korea. A high-purity natSm foil in disc shape was used for the irradiation and the induced photo-peak activity of the γ-rays of 143m,gSm in the irradiated sample was measured with a HPGe detector. The experimental data were analyzed through the Gamma Vision program and IR was obtained using a decay equation. The present results are compared with the literature data at other energies. It was found that the IR of 143m,gSm increases sharply from 12 to 20 MeV due to the GDR effect and thereafter remains nearly constant or increases slowly with the end-point bremsstrahlung energy.

  16. The Turnbull correlation and the freezing of stratospheric aerosol droplets

    NASA Astrophysics Data System (ADS)

    MacKenzie, A. Robert; Laaksonen, Ari; Batris, Evangelos; Kulmala, Markku

    1998-05-01

    An empirical correlation that is important in the calculation of homogeneous freezing probabilities, the "Turnbull correlation" for interfacial tensions, has been reevaluated and applied to systems of interest as possible components of polar stratospheric clouds (PSCs). The systems studied were: sulphuric acid solutions freezing to water ice and sulphuric acid tetrahydrate (SAT); and nitric acid solutions freezing to nitric acid trihydrate (NAT) and nitric acid dihydrate (NAD). The calculations have been compared to experimental data: agreement is generally good, although aerosol freezing experiments, which would rigorously test the theory, have not been made for NAT. Of the three measurements of aerosol freezing to NAD, the calculations are closer to those measurements showing a lower freezing temperature, of about 175-177 K. The comparison substantially improves our confidence in our understanding of the mechanisms of PSC formation. Freezing of stratospheric aerosol to water ice remains the most plausible first step in solid-particle PSC formation if homogeneous freezing is the mechanism by which solid-particle PSC formation occurs.

  17. Acid Rain.

    ERIC Educational Resources Information Center

    Openshaw, Peter

    1987-01-01

    Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)

  18. Solid-state photochemistry as a formation mechanism for Titan's stratospheric C4N2 ice clouds

    NASA Astrophysics Data System (ADS)

    Anderson, C. M.; Samuelson, R. E.; Yung, Y. L.; McLain, J. L.

    2016-04-01

    We propose that C4N2 ice clouds observed in Titan's springtime polar stratosphere arise due to solid-state photochemistry occurring within extant ice cloud particles of HCN-HC3N mixtures. This formation process resembles the halogen-induced ice particle surface chemistry that leads to condensed nitric acid trihydrate (NAT) particles and ozone depletion in Earth's polar stratosphere. As our analysis of the Cassini Composite Infrared Spectrometer 478 cm-1 ice emission feature demonstrates, this solid-state photochemistry mechanism eliminates the need for the relatively high C4N2 saturation vapor pressures required (even though they are not observed) when the ice is produced through the usual procedure of direct condensation from the vapor.

  19. Selective oxidation of trimethylolpropane to 2,2-bis(hydroxymethyl)butyric acid using growing cells of Corynebacterium sp. ATCC 21245.

    PubMed

    Sayed, Mahmoud; Dishisha, Tarek; Sayed, Waiel F; Salem, Wesam M; Temerk, Hanan A; Pyo, Sang-Hyun

    2016-03-10

    Multifunctional chemicals including hydroxycarboxylic acids are gaining increasing interest due to their growing applications in the polymer industry. One approach for their production is a biological selective oxidation of polyols, which is difficult to achieve by conventional chemical catalysis. In the present study, trimethylolpropane (TMP), a trihydric alcohol, was subjected to selective oxidation using growing cells of Corynebacterium sp. ATCC 21245 as a biocatalyst and yielding the dihydroxy-monocarboxylic acid, 2,2-bis(hydroxymethyl)butyric acid (BHMB). The study revealed that co-substrates are crucial for this reaction. Among the different evaluated co-substrates, a mixture of glucose, xylose and acetate at a ratio of 5:5:2 was found optimum. The optimal conditions for biotransformation were pH 8, 1v/v/m airflow and 500rpm stirring speed. In batch mode of operation, 70.6% of 5g/l TMP was converted to BHMB in 10 days. For recovery of the product the adsorption pattern of BHMB to the anion exchange resin, Ambersep(®) 900 (OH(-)), was investigated in batch and column experiments giving maximum static and dynamic binding capacities of 135 and 144mg/g resin, respectively. BHMB was separated with 89.7% of recovery yield from the fermentation broth. The approach is applicable for selective oxidation of other highly branched polyols by biotransformation. PMID:26804932

  20. Population pharmacokinetic analysis of isoniazid, acetylisoniazid, and isonicotinic acid in healthy volunteers.

    PubMed

    Seng, Kok-Yong; Hee, Kim-Hor; Soon, Gaik-Hong; Chew, Nicholas; Khoo, Saye H; Lee, Lawrence Soon-U

    2015-11-01

    In this study, we aimed to quantify the effects of the N-acetyltransferase 2 (NAT2) phenotype on isoniazid (INH) metabolism in vivo and identify other sources of pharmacokinetic variability following single-dose administration in healthy Asian adults. The concentrations of INH and its metabolites acetylisoniazid (AcINH) and isonicotinic acid (INA) in plasma were evaluated in 33 healthy Asians who were also given efavirenz and rifampin. The pharmacokinetics of INH, AcINH, and INA were analyzed using nonlinear mixed-effects modeling (NONMEM) to estimate the population pharmacokinetic parameters and evaluate the relationships between the parameters and the elimination status (fast, intermediate, and slow acetylators), demographic status, and measures of renal and hepatic function. A two-compartment model with first-order absorption best described the INH pharmacokinetics. AcINH and INA data were best described by a two- and a one-compartment model, respectively, linked to the INH model. In the final model for INH, the derived metabolic phenotypes for NAT2 were identified as a significant covariate in the INH clearance, reducing its interindividual variability from 86% to 14%. The INH clearance in fast eliminators was 1.9- and 7.7-fold higher than in intermediate and slow eliminators, respectively (65 versus 35 and 8 liters/h). Creatinine clearance was confirmed as a significant covariate for AcINH clearance. Simulations suggested that the current dosing guidelines (200 mg for 30 to 45 kg and 300 mg for >45 kg) may be suboptimal (3 mg/liter ≤ Cmax ≤ 6 mg/liter) irrespective of the acetylator class. The analysis established a model that adequately characterizes INH, AcINH, and INA pharmacokinetics in healthy Asians. Our results refine the NAT2 phenotype-based predictions of the pharmacokinetics for INH. PMID:26282412

  1. Population Pharmacokinetic Analysis of Isoniazid, Acetylisoniazid, and Isonicotinic Acid in Healthy Volunteers

    PubMed Central

    Seng, Kok-Yong; Hee, Kim-Hor; Soon, Gaik-Hong; Chew, Nicholas; Khoo, Saye H.

    2015-01-01

    In this study, we aimed to quantify the effects of the N-acetyltransferase 2 (NAT2) phenotype on isoniazid (INH) metabolism in vivo and identify other sources of pharmacokinetic variability following single-dose administration in healthy Asian adults. The concentrations of INH and its metabolites acetylisoniazid (AcINH) and isonicotinic acid (INA) in plasma were evaluated in 33 healthy Asians who were also given efavirenz and rifampin. The pharmacokinetics of INH, AcINH, and INA were analyzed using nonlinear mixed-effects modeling (NONMEM) to estimate the population pharmacokinetic parameters and evaluate the relationships between the parameters and the elimination status (fast, intermediate, and slow acetylators), demographic status, and measures of renal and hepatic function. A two-compartment model with first-order absorption best described the INH pharmacokinetics. AcINH and INA data were best described by a two- and a one-compartment model, respectively, linked to the INH model. In the final model for INH, the derived metabolic phenotypes for NAT2 were identified as a significant covariate in the INH clearance, reducing its interindividual variability from 86% to 14%. The INH clearance in fast eliminators was 1.9- and 7.7-fold higher than in intermediate and slow eliminators, respectively (65 versus 35 and 8 liters/h). Creatinine clearance was confirmed as a significant covariate for AcINH clearance. Simulations suggested that the current dosing guidelines (200 mg for 30 to 45 kg and 300 mg for >45 kg) may be suboptimal (3 mg/liter ≤ Cmax ≤ 6 mg/liter) irrespective of the acetylator class. The analysis established a model that adequately characterizes INH, AcINH, and INA pharmacokinetics in healthy Asians. Our results refine the NAT2 phenotype-based predictions of the pharmacokinetics for INH. PMID:26282412

  2. Measurement and simulation of the cross sections for nuclide production in {sup nat}W and {sup 181}Ta targets irradiated with 0.04- to 2.6-GeV protons

    SciTech Connect

    Titarenko, Yu. E. Batyaev, V. F.; Titarenko, A. Yu.; Butko, M. A.; Pavlov, K. V.; Florya, S. N.; Tikhonov, R. S.; Zhivun, V. M.; Ignatyuk, A. V.; Mashnik, S. G.; Leray, S.; Boudard, A.; Cugnon, J.; Mancusi, D.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Mank, G.; Gudowski, W.

    2011-04-15

    The cross sections for nuclide production in thin {sup nat}Wand {sup 181}Ta targets irradiated by 0.04-2.6-GeV protons have been measured by direct {gamma} spectrometry using two {gamma} spectrometers with the resolutions of 1.8 and 1.7 keV in the {sup 60}Co 1332-keV {gamma} line. As a result, 1895 yields of radioactive residual product nuclei have been obtained. The {sup 27}Al(p, x){sup 22}Na reaction has been used as a monitor reaction. The experimental data have been compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations.

  3. Measurement and simulation of the cross sections for nuclide production in {sup 93}Nb and {sup nat}Ni targets irradiated with 0.04- to 2.6-GeV protons

    SciTech Connect

    Titarenko, Yu. E. Batyaev, V. F.; Titarenko, A. Yu.; Butko, M. A.; Pavlov, K. V.; Florya, S. N.; Tikhonov, R. S.; Zhivun, V. M.; Ignatyuk, A. V.; Mashnik, S. G.; Leray, S.; Boudard, A.; Cugnon, J.; Mancusi, D.; Yariv, Y.; Nishihara, K.; Matsuda, N.; Kumawat, H.; Mank, G.; Gudowski, W.

    2011-04-15

    The cross sections for nuclide production in thin {sup 93}Nb and {sup nat}Ni targets irradiated by 0.04- to 2.6-GeV protons have been measured by direct {gamma} spectrometry using two {gamma} spectrometers with the resolutions of 1.8 and 1.7 keV in the {sup 60}Co 1332-keV {gamma} line. As a result, 1112 yields of radioactive residual nuclei have been obtained. The {sup 27}Al(p, x){sup 22}Na reaction has been used as a monitor reaction. The experimental data have been compared with the MCNPX (BERTINI, ISABEL), CEM03.02, INCL4.2, INCL4.5, PHITS, and CASCADE07 calculations.

  4. Photonuclear Studies for the Isomeric Yield Ratios in the Production of natFe(γ,xnp)52m,gMn with 50-,60-, and 70-MeV Bremsstrahlung

    NASA Astrophysics Data System (ADS)

    Shakilur Rahman, Md.; Kim, Guinyun; Kim, Kyung-Sook; Lee, Manwoo; Moinul Haque Meaze, A. K. M.

    2016-02-01

    The isomeric yield ratios in the production of natFe(γ,xnp)52m,gMn have been measured with photonuclear reactions. The high purity natural Fe metallic foils were used and irradiated with bremsstrahlung beams of end point energy 50-, 60-, and 70-MeV. The bremsstrahlung beams are produced with high energy electron beam struck with 0.1mm thin tungsten target. The activation method has been used and hence the induced activities in the irradiated foils were measured by off-line γ-ray spectrometric technique using HPGe detector coupled to a PC-based 4K MCA. The experimental values of isomeric ratios are compared with the theoretical values by statistical model code TALYS. The detail of the formation of isomers by photonuclear reactions together with the literature values of the investigated nuclides are compared and discussed.

  5. Amino acids

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/002222.htm Amino acids To use the sharing features on this page, please enable JavaScript. Amino acids are organic compounds that combine to form proteins . ...

  6. Mefenamic Acid

    MedlinePlus

    Mefenamic acid is used to relieve mild to moderate pain, including menstrual pain (pain that happens before or during a menstrual period). Mefenamic acid is in a class of medications called NSAIDs. ...

  7. Aminocaproic Acid

    MedlinePlus

    Aminocaproic acid is used to control bleeding that occurs when blood clots are broken down too quickly. This type ... the baby is ready to be born). Aminocaproic acid is also used to control bleeding in the ...

  8. Ascorbic Acid

    MedlinePlus

    Ascorbic acid is used to prevent and treat scurvy, a disease caused by a lack of vitamin C in ... Ascorbic acid comes in extended-release (long-acting) capsules and tablets, lozenges, syrup, chewable tablets, and liquid drops to ...

  9. Acid mucopolysaccharides

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003368.htm Acid mucopolysaccharides To use the sharing features on this page, please enable JavaScript. Acid mucopolysaccharides is a test that measures the amount ...

  10. Ethacrynic Acid

    MedlinePlus

    Ethacrynic acid, a 'water pill,' is used to treat swelling and fluid retention caused by various medical problems. It ... Ethacrynic acid comes as a tablet to take by mouth. It is usually taken once or twice a day ...

  11. Status of Numerical Modelling of Polar Stratospheric Clouds and Their Effect on Stratospheric Chemistry

    NASA Astrophysics Data System (ADS)

    Wang, X.; Michelangeli, D. V.; Kletskin, I.

    2003-04-01

    A multi-dimensional stratospheric model for aerosols including detailed Polar Stratospheric Cloud (PSC) microphysical processes, heterogeneous chemistry and comprehensive gas phase chemistry is being developed to study the formation and evolution of PSCs and the effect of heterogeneous reactions occurring on the surface of PSCs on polar stratospheric ozone. The model can be used in parcel mode or one, two, three dimensions. Background sulfate aerosols, frozen sulfate aerosols (sulfuric acid tetrahydrate, SAT) , Type 1a PSCs (nitric acid trihydrate, NAT ), Type 1b PSCs (supercooled ternary solution, STS ), and Type 2 PSCs (water ice crystals) are all treated as interactive elements in the model. The possible microphysical processes included in the model are: uptake of HNO_3 and H_2O on background sulphate droplets to form Type 1b and evaporation of HNO_3 and H_2O from Type 1b to return background sulphate droplets; homogenous freezing of Type 1b to form Type 2 PSCs; heterogeneous nucleation of SAT to form NAT particles, and NAT to form Type 2 PSC ice; deliquescence of SAT to form Type 1b STS and melting of SAT to form background sulphate droplets. In addition, the model involves the growth of ice and NAT by H_2O and HNO_3 deposition, evaporation, coagulation, sedimentation and transport processes. Heterogeneous reactions of nitrogen, chlorine, and bromine compounds in and on sulphate droplets, ternary, and ice particles are considered in the model. In this paper, preliminary simulation results of sensitivity tests are presented to display the basic features of PSCs and their effects on polar ozone. Comparisons with satellite measurements will be discussed.

  12. Metastable Phases in Ice Clouds

    NASA Astrophysics Data System (ADS)

    Weiss, Fabian; Baloh, Philipp; Kubel, Frank; Hoelzel, Markus; Parker, Stewart; Grothe, Hinrich

    2014-05-01

    Polar Stratospheric Clouds and Cirrus Clouds contain both, pure water ice and phases of nitric acid hydrates. Preferentially for the latter, the thermodynamically stable phases have intensively been investigated in the past (e.g. nitric acid trihydrate, beta-NAT). As shown by Peter et al. [1] the water activity inside clouds is higher than expected, which might be explained by the presence of metastable stable phases (e.g. cubic ice). However, also metastable nitric acid hydrates might be important due to the inherent non-equilibrium freezing conditions in the upper atmosphere. The delta ice theory of Gao et al. [2] presents a model approach to solve this problem by involving both metastable ice and NAT as well. So it is of high interest to investigate the metastable phase of NAT (i.e. alpha-NAT), the structure of which was unknown up to the presence. In our laboratory a production procedure for metastable alpha-NAT has been developed, which gives access to neutron diffraction and X-ray diffraction measurements, where sample quantities of several Gramm are required. The diffraction techniques were used to solve the unknown crystalline structure of metastable alpha-NAT, which in turn allows the calculation of the vibrational spectra, which have also been recorded by us in the past. Rerefences [1] Peter, T., C. Marcolli, P. Spichtinger, T. Corti, M. B. Baker, and T. Koop. When dry air is too humid. Science, 314:1399-1402, 2006. [2] Gao, R., P. Popp, D. Fahey, T. Marcy, R. L. Herman, E. Weinstock, D. Baumgardener, T. Garrett, K. Rosenlof, T. Thompson, T. P. Bui, B. Ridley, S. C. Wofsy, O. B. Toon, M. Tolbert, B. Kärcher, Th. Peter, P. K. Hudson, A. Weinheimer, and A. Heymsfield. Evidence That Nitric Acid Increases Relative Humidity in Low-Temperature Cirrus Clouds, Science, 303:516-520, 2004. [3] Tizek, H., E. Knözinger, and H. Grothe. Formation and phase distribution of nitric acid hydrates in the mole fraction range xHNO3<0.25: A combined XRD and IR study, PCCP, 6

  13. Valproic Acid

    MedlinePlus

    Valproic acid is used alone or with other medications to treat certain types of seizures. Valproic acid is also used to treat mania (episodes of ... to relieve headaches that have already begun. Valproic acid is in a class of medications called anticonvulsants. ...

  14. Fatty acids - trans fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The data supporting a negative effect of dietary trans fatty acids on cardiovascular disease risk is consistent. The primary dietary sources of trans fatty acids include partially hydrogenated fat and rudiment fat. The adverse effect of trans fatty acids on plasma lipoprotein profiles is consisten...

  15. Transmission of Hepatitis C Virus From Organ Donors Despite Nucleic Acid Test Screening.

    PubMed

    Suryaprasad, A; Basavaraju, S V; Hocevar, S N; Theodoropoulos, N; Zuckerman, R A; Hayden, T; Forbi, J C; Pegues, D; Levine, M; Martin, S I; Kuehnert, M J; Blumberg, E A

    2015-07-01

    Nucleic acid testing (NAT) for hepatitis C virus (HCV) is recommended for screening of organ donors, yet not all donor infections may be detected. We describe three US clusters of HCV transmission from donors at increased risk for HCV infection. Donor's and recipients' medical records were reviewed. Newly infected recipients were interviewed. Donor-derived HCV infection was considered when infection was newly detected after transplantation in recipients of organs from increased risk donors. Stored donor sera and tissue samples were tested for HCV RNA with high-sensitivity quantitative PCR. Posttransplant and pretransplant recipient sera were tested for HCV RNA. Quasispecies analysis of hypervariable region-1 was used to establish genetic relatedness of recipient HCV variants. Each donor had evidence of injection drug use preceding death. Of 12 recipients, 8 were HCV-infected-6 were newly diagnosed posttransplant. HCV RNA was retrospectively detected in stored samples from donor immunologic tissue collected at organ procurement. Phylogenetic analysis showed two clusters of closely related HCV variants from recipients. These investigations identified the first known HCV transmissions from increased risk organ donors with negative NAT screening, indicating very recent donor infection. Recipient informed consent and posttransplant screening for blood-borne pathogens are essential when considering increased risk donors. PMID:25943299

  16. Unprecedented Evidence for Large Scale Heterogeneous Nucleation of Polar Stratospheric Clouds, Likely by Nanometer-Sized Meteoritic Particles

    NASA Astrophysics Data System (ADS)

    Engel, I.; Pitts, M. C.; Luo, B.; Hoyle, C. R.; Zobrist, B.; Jacot, L.; Poole, L. R.; Grooss, J.; Weigel, R.; Borrmann, S.; Ebert, M.; Duprat, J.; Peter, T.

    2012-12-01

    Recent observations cast serious doubts on our understanding of the processes responsible for polar stratospheric cloud (PSC) formation. PSCs play crucial roles in polar ozone chemistry by hosting heterogeneous reactions and by removal of reactive nitrogen through sedimenting nitric acid trihydrate (NAT) particles. An extensive field campaign took place in the Arctic during the winter 2009/2010 within the European Union project RECONCILE, complemented by measurements from the spaceborne CALIOP (Cloud-Aerosol LIdar with Orthogonal Polarization) instrument. Through trajectory and microphysical box model calculations, we analyzed CALIOP data from the RECONCILE winter to investigate the nucleation of PSC particles in detail. One significant finding was that liquid/NAT mixture PSCs were prevalent in late December 2009, a period during which no ice PSCs were observed, and temperatures were higher by 6 K than required for homogeneous ice freezing at the onset of PSC formation. These NAT particles must have formed through some non-ice nucleation mechanism, which runs counter to the widely held view that the only efficient NAT nuclei were ice crystals formed by homogeneous freezing of STS droplets. Furthermore, in mid-January 2010, a large region of the Arctic vortex cooled below the frost point, leading to widespread synoptic-scale ice PSCs, unusual for the Arctic. Our modeling studies indicate that a match with the CALIOP data calls for new heterogeneous nucleation mechanisms for both NAT and ice particles, namely freezing on nanometer-sized, solid nuclei immersed in the liquid stratospheric aerosols. Number concentrations of non-volatile particles were measured in situ during RECONCILE by means of the heated channel of the condensation nuclei (CN) counter COPAS on board of the high-flying aircraft Geophysica. 60-80 % of all CN survived heating to 250 °C. Offline Environmental Scanning Electron Microscopy and Energy Dispersive X-Ray Analysis of RECONCILE impactor samples

  17. New approaches to target the mycolic acid biosynthesis pathway for the development of tuberculosis therapeutics.

    PubMed

    North, E Jeffrey; Jackson, Mary; Lee, Richard E

    2014-01-01

    Mycolic acids are the major lipid components of the unique mycobacterial cell wall responsible for the protection of the tuberculosis bacilli from many outside threats. Mycolic acids are synthesized in the cytoplasm and transported to the outer membrane as trehalose- containing glycolipids before being esterified to the arabinogalactan portion of the cell wall and outer membrane glycolipids. The large size of these unique fatty acids is a result of a huge metabolic investment that has been evolutionarily conserved, indicating the importance of these lipids to the mycobacterial cellular survival. There are many key enzymes involved in the mycolic acid biosynthetic pathway, including fatty acid synthesis (KasA, KasB, MabA, InhA, HadABC), mycolic acid modifying enzymes (SAM-dependent methyltransferases, aNAT), fatty acid activating and condensing enzymes (FadD32, Acc, Pks13), transporters (MmpL3) and tranferases (Antigen 85A-C) all of which are excellent potential drug targets. Not surprisingly, in recent years many new compounds have been reported to inhibit specific portions of this pathway, discovered through both phenotypic screening and target enzyme screening. In this review, we analyze the new and emerging inhibitors of this pathway discovered in the post-genomic era of tuberculosis drug discovery, several of which show great promise as selective tuberculosis therapeutics. PMID:24245756

  18. New Approaches to Target the Mycolic Acid Biosynthesis Pathway for the Development of Tuberculosis Therapeutics

    PubMed Central

    North, E. Jeffrey; Jackson, Mary; Lee, Richard E.

    2015-01-01

    Mycolic acids are the major lipid component of the unique mycobacterial cell wall responsible for the protection of the tuberculosis bacilli from many outside threats. Mycolic acids are synthesized in the cytoplasm and transported to the outer membrane as trehalose-containing glycolipids before being esterified to the arabinogalactan portion of the cell wall and outer membrane glycolipids. The large size of these unique fatty acids is a result of a huge metabolic investment that has been evolutionarily conserved, indicating the importance of these lipids to the mycobacterial cellular survival. There are many key enzymes involved in the mycolic acid biosynthetic pathway, including fatty acid synthesis (KasA, KasB, MabA, InhA, HadABC), mycolic acid modifying enzymes (SAM-dependent methyltransferases, aNAT), fatty acid activating and condensing enzymes (FadD32, Acc, Pks13), transporters (MmpL3) and tranferases (Antigen 85A-C) all of which are excellent potential drug targets. Not surprisingly, in recent years many new compounds have been reported to inhibit specific portions of this pathway, discovered through both phenotypic screening and target enzyme screening. In this review, we analyze the new and emerging inhibitors of this pathway discovered in the post-genomic era of tuberculosis drug discovery, several of which show great promise as selective tuberculosis therapeutics. PMID:24245756

  19. Polar Stratospheric Cloud evolution and chlorine activation measured by CALIPSO and MLS, and modelled by ATLAS

    NASA Astrophysics Data System (ADS)

    Nakajima, H.; Wohltmann, I.; Wegner, T.; Takeda, M.; Pitts, M. C.; Poole, L. R.; Lehmann, R.; Santee, M. L.; Rex, M.

    2015-08-01

    We examined observations of polar stratospheric clouds (PSCs) by CALIPSO and of HCl, ClO and HNO3 by MLS along air mass trajectories to investigate the dependence of the inferred PSC composition on the temperature history of the air parcels, and the dependence of the level of chlorine activation on PSC composition. Several case studies based on individual trajectories from the Arctic winter 2009/10 were conducted, with the trajectories chosen such that the first processing of the air mass by PSCs in this winter occurred on the trajectory. Transitions of PSC composition classes were observed to be highly dependent on the temperature history. In cases of a gradual temperature decrease, nitric acid trihydrate (NAT) and super-cooled ternary solution (STS) mixture clouds were observed. In cases of rapid temperature decrease, STS clouds were first observed, followed by NAT/STS mixture clouds. When temperatures dropped below the frost point, ice clouds formed, and then transformed into NAT/STS mixture clouds when temperature increased above the frost point. The threshold temperature for rapid chlorine activation on PSCs is approximately 4 K below the NAT existence temperature, TNAT. Furthermore, simulations of the ATLAS chemistry and transport box model along the trajectories were used to corroborate the measurements and show good agreement with the observations. Rapid chlorine activation was observed when an airmass encountered PSCs. The observed and modelled dependence of the rate of chlorine activation on the PSC composition class was small. Usually, chlorine activation was limited by the amount of available ClONO2. Where ClONO2 was not the limiting factor, a large dependence on temperature was evident.

  20. Polar stratospheric cloud evolution and chlorine activation measured by CALIPSO and MLS, and modeled by ATLAS

    NASA Astrophysics Data System (ADS)

    Nakajima, Hideaki; Wohltmann, Ingo; Wegner, Tobias; Takeda, Masanori; Pitts, Michael C.; Poole, Lamont R.; Lehmann, Ralph; Santee, Michelle L.; Rex, Markus

    2016-03-01

    We examined observations of polar stratospheric clouds (PSCs) by CALIPSO, and of HCl and ClO by MLS along air mass trajectories, to investigate the dependence of the inferred PSC composition on the temperature history of the air parcels and the dependence of the level of chlorine activation on PSC composition. Several case studies based on individual trajectories from the Arctic winter 2009/2010 were conducted, with the trajectories chosen such that the first processing of the air mass by PSCs in this winter occurred on the trajectory. Transitions of PSC composition classes were observed to be highly dependent on the temperature history. In cases of a gradual temperature decrease, nitric acid trihydrate (NAT) and super-cooled ternary solution (STS) mixture clouds were observed. In cases of rapid temperature decrease, STS clouds were first observed, followed by NAT/STS mixture clouds. When temperatures dropped below the frost point, ice clouds formed and then transformed into NAT/STS mixture clouds when temperature increased above the frost point. The threshold temperature for rapid chlorine activation on PSCs is approximately 4 K below the NAT existence temperature, TNAT. Furthermore, simulations of the ATLAS chemistry and transport box model along the trajectories were used to corroborate the measurements and show good agreement with the observations. Rapid chlorine activation was observed when an air mass encountered PSCs. Usually, chlorine activation was limited by the amount of available ClONO2. Where ClONO2 was not the limiting factor, a large dependence on temperature was evident.

  1. CALIPSO Polar Stratospheric Cloud Observations from 2006-2015

    NASA Technical Reports Server (NTRS)

    Pitts, Michael C.; Poole, Lamont R.

    2015-01-01

    Polar stratospheric clouds (PSCs) play a crucial role in the springtime chemical depletion of ozone at high latitudes. PSC particles (primarily supercooled ternary solution, or STS droplets) provide sites for heterogeneous chemical reactions that transform stable chlorine and bromine reservoir species into highly reactive ozone-destructive forms. Furthermore, large nitric acid trihydrate (NAT) PSC particles can irreversibly redistribute odd nitrogen through gravitational sedimentation (a process commonly known as denitrification), which prolongs the ozone depletion process by slowing the reformation of the stable chlorine reservoirs. Spaceborne observations from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) lidar on the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) satellite are providing a rich new dataset for studying PSCs. CALIPSO is an excellent platform for studying polar processes with CALIOP acquiring, on average, over 300,000 backscatter profiles daily at latitudes between 55o and 82o in both hemispheres. PSCs are detected in the CALIOP backscatter profiles using a successive horizontal averaging scheme that enables detection of strongly scattering PSCs (e.g., ice) at the finest possible spatial resolution (5 km), while enhancing the detection of very tenuous PSCs (e.g., low number density NAT) at larger spatial scales (up to 135 km). CALIOP PSCs are separated into composition classes (STS; liquid/NAT mixtures; and ice) based on the ensemble 532-nm scattering ratio (the ratio of total-to-molecular backscatter) and 532-nm particulate depolarization ratio (which is sensitive to the presence of non-spherical, i.e. NAT and ice particles). In this paper, we will provide an overview of the CALIOP PSC detection and composition classification algorithm and then examine the vertical and spatial distribution of PSCs in the Arctic and Antarctic on vortex-wide scales for entire PSC seasons over the more than nine-year data

  2. 9+ Years of CALIPSO PSC Observations: An Evolving Climatology

    NASA Technical Reports Server (NTRS)

    Pitts, Michael C.; Poole, Lamont R.

    2015-01-01

    Polar stratospheric clouds (PSCs) play a crucial role in the springtime chemical depletion of ozone at high latitudes. PSC particles (primarily supercooled ternary solution, or STS droplets) provide sites for heterogeneous chemical reactions that transform stable chlorine and bromine reservoir species into highly reactive ozone-destructive forms. Furthermore, large nitric acid trihydrate (NAT) PSC particles can irreversibly redistribute odd nitrogen through gravitational sedimentation (a process commonly known as denitrification), which prolongs the ozone depletion process by slowing the reformation of the stable chlorine reservoirs. Spaceborne observations from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) lidar on the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) satellite are providing a rich new dataset for studying PSCs. CALIPSO is an excellent platform for studying polar processes with CALIOP acquiring, on average, over 300,000 backscatter profiles daily at latitudes between 55o and 82o in both hemispheres. PSCs are detected in the CALIOP backscatter profiles using a successive horizontal averaging scheme that enables detection of strongly scattering PSCs (e.g., ice) at the finest possible spatial resolution (5 km), while enhancing the detection of very tenuous PSCs (e.g., low number density NAT) at larger spatial scales (up to 135 km). CALIOP PSCs are separated into composition classes (STS; liquid/NAT mixtures; and ice) based on the ensemble 532-nm scattering ratio (the ratio of total-to-molecular backscatter) and 532-nm particulate depolarization ratio (which is sensitive to the presence of non-spherical, i.e. NAT and ice particles). In this paper, we will provide an overview of the CALIOP PSC detection and composition classification algorithm and then examine the vertical and spatial distribution of PSCs in the Arctic and Antarctic on vortex-wide scales for entire PSC seasons over the more than nine-year data

  3. CALIPSO Polar Stratospheric Cloud Observations from 2006-2015

    NASA Astrophysics Data System (ADS)

    Pitts, Michael; Poole, Lamont

    2015-04-01

    Polar stratospheric clouds (PSCs) play a crucial role in the springtime chemical depletion of ozone at high latitudes. PSC particles (primarily supercooled ternary solution, or STS droplets) provide sites for heterogeneous chemical reactions that transform stable chlorine and bromine reservoir species into highly reactive ozone-destructive forms. Furthermore, large nitric acid trihydrate (NAT) PSC particles can irreversibly redistribute odd nitrogen through gravitational sedimentation (a process commonly known as denitrification), which prolongs the ozone depletion process by slowing the reformation of the stable chlorine reservoirs. Spaceborne observations from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) lidar on the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) satellite are providing a rich new dataset for studying PSCs. CALIPSO is an excellent platform for studying polar processes with CALIOP acquiring, on average, over 300,000 backscatter profiles daily at latitudes between 55 and 82 degrees in both hemispheres. PSCs are detected in the CALIOP backscatter profiles using a successive horizontal averaging scheme that enables detection of strongly scattering PSCs (e.g., ice) at the finest possible spatial resolution (5 km), while enhancing the detection of very tenuous PSCs (e.g., low number density NAT) at larger spatial scales (up to 135 km). CALIOP PSCs are separated into composition classes (STS; liquid/NAT mixtures; and ice) based on the ensemble 532-nm scattering ratio (the ratio of total-to-molecular backscatter) and 532-nm particulate depolarization ratio (which is sensitive to the presence of non-spherical, i.e. NAT and ice particles). In this paper, we will provide an overview of the CALIOP PSC detection and composition classification algorithm and then examine the vertical and spatial distribution of PSCs in the Arctic and Antarctic on vortex-wide scales for entire PSC seasons over the more than nine

  4. Fourier transform infrared studies of the interaction of HCl with model polar stratospheric cloud films

    NASA Technical Reports Server (NTRS)

    Koehler, Birgit G.; Mcneill, Laurie S.; Middlebrook, Ann M.; Tolbert, Margaret A.

    1993-01-01

    Heterogeneous reactions involving hydrochloric acid adsorbed on the surfaces of polar stratospheric clouds (PSCs) are postulated to contribute to polar ozone loss. Using FTIR spectroscopy to probe the condensed phase, we have examined the interaction of HCl with ice and nitric acid trihydrate (NAT) films representative of types II and I PSCs, respectively. For HCl pressures in the range of 10 exp -7 to 10 exp -5 Torr, our FTIR studies show that a small amount of crystalline HCl-6H2O formed on or in ice at 155 K. However, for higher HCl pressures, we observed that the entire film of ice rapidly converted into an amorphous 4:1 H2O:HCl mixture. From HCl-uptake experiments with P(HCl) = 8 x 10 exp -7 Torr, we estimate roughly that the diffusion coefficient of HCl in ice is around 2 x 10 exp -12 sq cm/s at 158 K. For higher temperatures more closely approximating those found in the stratosphere, we were unable to detect bulk HCl uptake by ice. Indirect evidence suggests that HCl adsorption onto the surface of model PSC films inhibited the evaporation of both ice and NAT by 3-5 K.

  5. Acid Deposition

    EPA Science Inventory

    This indicator presents acid deposition trends in the contiguous U.S. from 1989 to 2007. Data are broken down by wet and dry deposition and deposition of nitrogen and sulfur compounds. Acid deposition is particularly damaging to lakes, streams, and forests and the plants and a...

  6. Acid rain

    SciTech Connect

    White, J.C. )

    1988-01-01

    This book presents the proceedings of the third annual conference sponsored by the Acid Rain Information Clearinghouse (ARIC). Topics covered include: Legal aspects of the source-receptor relationship: an energy perspective; Scientific uncertainty, agency inaction, and the courts; and Acid rain: the emerging legal framework.

  7. Acid rain

    SciTech Connect

    Elsworth, S.

    1985-01-01

    This book was written in a concise and readable style for the lay public. It's purpose was to make the public aware of the damage caused by acid rain and to mobilize public opinion to favor the elimination of the causes of acid rain.

  8. Acid rain

    SciTech Connect

    Sweet, W.

    1980-06-20

    Acid precipitation includes not only rain but also acidified snow, hail and frost, as well as sulfur and nitrogen dust. The principal source of acid precipitation is pollution emitted by power plants and smelters. Sulfur and nitrogen compounds contained in the emissions combine with moisture to form droplets with a high acid content - sometimes as acidic as vinegar. When sufficiently concentrated, these acids can kill fish and damage material structures. Under certain circumstances they may reduce crop and forest yields and cause or aggravate respiratory diseases in humans. During the summer, especially, pollutants tend to collect over the Great Lakes in high pressure systems. Since winds typically are westerly and rotate clockwise around high pressure systems, the pollutants gradually are dispersed throughout the eastern part of the continent.

  9. Asparagusic acid.

    PubMed

    Mitchell, Stephen C; Waring, Rosemary H

    2014-01-01

    Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for α-lipoic acid in α-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications. PMID:24099657

  10. [Gastric Acid].

    PubMed

    Ruíz Chávez, R

    1996-01-01

    Gastric acid, a product of parietal cells secretion, full fills multiple biological roles which are absolutely necessary to keep corporal homeostasis. The production of the acid depends upon an effector cellular process represented in the first step by histamine, acetilcholine and gastrin, first messengers of the process. These interact with specific receptors than in sequence activate second messengers -cAMP and the calcium-calmodulin system- which afterwards activate a kinase. An specific protein is then phosphorilated by this enzyme, being the crucial factor that starts the production of acid. Finally, a proton bomb, extrudes the acid towards the gastric lumen. The secretion process mentioned above, is progressive lyactivated in three steps, two of which are stimulators -cephalic and gastric phases- and the other one inhibitor or intestinal phase. These stages are started by mental and neurological phenomena -thought, sight, smell or memory-; by food, drugs or other ingested substances; and by products of digestion. Changes in regulation of acid secretion, in the structure of gastro-duodenal mucosal barrier by a wide spectrum of factors and agents including food, drugs and H. pylori, are the basis of acid-peptic disease, entity in which gastric acid plays a fundamental role. From the therapeutic point of view, so at the theoretical as at the practical levels, t is possible to interfere with the secretion of acid by neutralization of some of the steps of the effector cellular process. An adequate knowledge of the basics related to gastric acid, allows to create strategies for the clinical handling of associated pathology, specifically in relation to peptic acid disease in all of the known clinical forms. PMID:12165790

  11. Acid fog

    SciTech Connect

    Hileman, B.

    1983-03-01

    Fog in areas of southern California previously thought to be pollution-free has been shown to have a pH as low as 1.69. It has been found to be most acidic after smoggy days, suggesting that it forms on the aerosol associated with the previously exiting smog. Studies on Whiteface Mountain in the Adirondacks show that fog water is often 10 times as acidic as rainwater. As a result of their studies, California plans to spend $4 million on acid deposition research in the coming year. (JMT)

  12. Folic acid

    MedlinePlus

    ... in the blood vessel to keep it open. Bipolar disorder. Taking folic acid does not appear to improve the antidepressant effects of lithium in people with bipolar disorder. However, taking folate with the medication valproate improves ...

  13. Mefenamic Acid

    MedlinePlus

    ... as mefenamic acid may cause ulcers, bleeding, or holes in the stomach or intestine. These problems may ... like coffee grounds, blood in the stool, or black and tarry stools.Keep all appointments with your ...

  14. ACID RAIN

    EPA Science Inventory

    Acid precipitation has become one of the major environmental problems of this decade. It is a challenge to scientists throughout the world. Researchers from such diverse disciplines as plant pathology, soil science, bacteriology, meteorology and engineering are investigating diff...

  15. Acid Precipitation

    ERIC Educational Resources Information Center

    Likens, Gene E.

    1976-01-01

    Discusses the fact that the acidity of rain and snow falling on parts of the U.S. and Europe has been rising. The reasons are still not entirely clear and the consequences have yet to be well evaluated. (MLH)

  16. Carnosic acid.

    PubMed

    Birtić, Simona; Dussort, Pierre; Pierre, François-Xavier; Bily, Antoine C; Roller, Marc

    2015-07-01

    Carnosic acid (salvin), which possesses antioxidative and antimicrobial properties, is increasingly exploited within the food, nutritional health and cosmetics industries. Since its first extraction from a Salvia species (∼70 years ago) and its identification (∼50 years ago), numerous articles and patents (∼400) have been published on specific food and medicinal applications of Rosmarinus and Salvia plant extracts abundant in carnosic acid. In contrast, relevant biochemical, physiological or molecular studies in planta have remained rare. In this overview, recent advances in understanding of carnosic acid distribution, biosynthesis, accumulation and role in planta, and its applications are summarised. We also discuss the deficiencies in our understanding of the relevant biochemical processes, and suggest the molecular targets of carnosic acid. Finally, future perspectives and studies related to its potential roles are highlighted. PMID:25639596

  17. Aminocaproic Acid

    MedlinePlus

    Amicar® Oral Solution ... Aminocaproic acid comes as a tablet and a solution (liquid) to take by mouth. It is usually ... it at room temperature and away from excess heat and moisture (not in the bathroom). Throw away ...

  18. Tranexamic Acid

    MedlinePlus

    ... is used to treat heavy bleeding during the menstrual cycle (monthly periods) in women. Tranexamic acid is in ... tablets for more than 5 days in a menstrual cycle or take more than 6 tablets in a ...

  19. Screening Donated Blood for Transfusion Transmitted Infections by Serology along with NAT and Response Rate to Notification of Reactive Results: An Indian Experience.

    PubMed

    Chaurasia, Rahul; Zaman, Shamsuz; Das, Bankim; Chatterjee, Kabita

    2014-01-01

    Background. Transfusion safety begins with healthy donors. A fundamental part of preventing transfusion transmitted infections (TTIs) is to notify and counsel reactive donors. Donor notification and counselling protect the health of the donor and prevent secondary transmission of infectious diseases. Methods. 113,014 donations were screened for TTIs, namely, HIV, HBV, HCV, and syphilis, by serology and nucleic acid testing. All reactive donors were retested (wherever possible) and notified of their status by telephone or letter. All initial reactive screens were followed over six months. Results. We evaluated 2,838 (2.51%) cases with reactive screening test results (1.38% HBV, 0.54% HCV, 0.27% HIV, and 0.32% syphilis). Only 23.3% of donors (662) responded to notification. The response among voluntary donors was better as compared to the replacement donors (43.6% versus 21.2%). Only 373 (56.3%) responsive donors followed their first attendance at referral specialties. Over six months, only 176 of 662 (26.6%) reactive donors received treatment. Conclusion. Our study shed light on the importance of proper donor counselling and notification of TTI status to all reactive donors who opt to receive this information. There is also an urgent need to formulate the nationally acceptable guidelines for notification and follow-up of reactive donors. PMID:25485163

  20. Measurements of production cross sections of 10Be and 26Al by 120 GeV and 392 MeV proton bombardment of 89Y, 159Tb, and natCu targets

    DOE PAGESBeta

    Sekimoto, S.; Okumura, S.; Yashima, H.; Matsushi, Y.; Matsuzaki, H.; Matsumura, H.; Toyoda, A.; Oishi, K.; Matsuda, N.; Kasugai, Y.; et al

    2015-08-12

    The production cross sections of 10Be and 26Al were measured by accelerator mass spectrometry using 89Y, 159Tb, and natCu targets bombarded by protons with energies Ep of 120 GeV and 392 MeV. The production cross sections obtained for 10Be and 26Al were compared with those previously reported using Ep = 50 MeV–24 GeV and various targets. It was found that the production cross sections of 10Be monotonically increased with increasing target mass number when the proton energy was greater than a few GeV. On the other hand, it was also found that the production cross sections of 10Be decreased asmore » the target mass number increased from that of carbon to those near the mass numbers of nickel and zinc when the proton energy was below approximately 1 GeV. They also increased as the target mass number increased from near those of nickel and zinc to that of bismuth, in the same proton energy range. Similar results were observed in the production cross sections of 26Al, though the absolute values were quite different between 10Be and 26Al. As a result, the difference between these production cross sections may depend on the impact parameter (nuclear radius) and/or the target nucleus stiffness.« less

  1. NO3- Coordination in Aqueous Solutions by 15N/14N and 18O/natO Isotopic Substitution: What Can We Learn from Molecular Simulation?

    SciTech Connect

    Chialvo, Ariel A.; Vlcek, Lukas

    2014-12-16

    We explore the deconvolution of the water-nitrate correlations by the first-order difference approach involving neutron diffraction of heavy- and null-aqueous solutions of KNO3 under 14N 15N and natON 18ON substitutions to achieve a full characterization of the first water coordination around the nitrate ion. For that purpose we performed isobaric-isothermal simulations of 3.5m KNO3 aqueous solutions at ambient conditions to generate the relevant radial distribution functions (RDF) required in the analysis (a) to identify the individual partial contributions to the total neutron weighted distribution function, (b) to isolate and assess the contribution of NO3 -!K+ pair formation, (c) to test the accuracy of the NDIS-based coordination calculations and XRDbased assumptions, and (d) to describe the water coordination around both the nitrogen and oxygen sites of the nitrate ion.

  2. Exclusive studies of 130-270 MeV {sup 3}He- and 200-MeV proton-induced reactions on {sup 27}Al, {sup nat}Ag, and {sup 197}Au

    SciTech Connect

    Ginger, D. S.; Kwiatkowski, K.; Wang, G.; Hsi, W.-C.; Hudan, S.; Cornell, E.; Souza, R. T. de; Viola, V. E.; Korteling, R. G.

    2008-09-15

    Exclusive light-charged-particle and IMF spectra have been measured with the ISiS detector array for bombardments of {sup 27}Al, {sup nat}Ag, and {sup 197}Au nuclei with 130-270-MeV {sup 3}He and 200-MeV protons. The results are consistent with previous interpretations based on inclusive data that describe the global yield of complex fragments in terms of a time-dependent process. The emission mechanism for energetic nonequilibrium fragments observed at forward angles with momenta up to twice the beam momentum is also investigated. This poorly understood mechanism, for which the angular distributions indicate formation on a time scale comparable to the nuclear transit time, are accompanied primarily by thermal-like emissions. The data are most consistent with a schematic picture in which nonequilibrium fragments are formed in a localized region of the target nucleus at an early stage in the energy-dissipation process, where the combined effects of high energy density and Fermi motion produce the observed suprathermal spectra.

  3. Study of the peripheral projectile-like fragments from the reaction {sup 129}Xe on {sup 27}Al, {sup nat}Cu, {sup 139}La and {sup 165}Ho, at E/A = 50 MeV

    SciTech Connect

    Garcia-Solis, E.J.; Russ, D.E.; Madani, H.

    1996-02-01

    There are several reaction mechanisms identified for peripheral heavy-ion collisions. For low bombarding energies (E/A {approx} 10 MeV) the predominant reaction channel is the deep-inelastic reaction mechanism. In this process, the projectile and target form a rotating binary system, interchanging nucleons and angular momentum until they separate. At higher bombarding energies (E/A {approx} 50 to 100 MeV) incomplete fusion is thought to be the prevailing reaction channel. In this type of interaction part of the projectile merges with the target during the collision. Finally, for energies greater than 100 MeV/A, the main reaction channel is characterized by the formation of a highly-excited separate fragment (fireball) produced during the overlap between the projectile and the target. The data set studied was from an experiment designed to characterize the projectile-like products of the {sup 27}Al, {sup nat}Cu, {sup 139}La, and {sup 165}Ho reactions at E/A = 50 MeV, which was performed at the Michigan State University Super Cyclotron Laboratory (MSU-NSCL). The Maryland Forward Array (MFA), was used to measure projectile-like fragments in coincidence with target-like fragments and light-charge particles in the MSU 4{pi} detector.

  4. Experimental cross-sections of deuteron-induced reaction on 89Y up to 20 MeV; comparison of natTi(d,x)48V and 27Al(d,x)24Na monitor reactions

    NASA Astrophysics Data System (ADS)

    Lebeda, Ondřej; Štursa, Jan; Ráliš, Jan

    2015-10-01

    We measured cross-sections of the deuteron-induced reactions on 89Y in the energy range of 3.9-19.5 MeV. Excitation functions for formation of 88Zr, 89mZr, 89Zr, 88Y, 90mY and 87mSr were determined and compared with previously published data and prediction of the TALYS code. Thick target yields for production of 88Zr, 89Zrcum, 88Y, 90mY and 87mSr were calculated from the measured cross-sections. Achievable activity versus radionuclidic purity of medically relevant 89Zr is discussed and compared with the production via the 89Y(p,n) reaction. Parallel use of titanium and aluminium beam monitors revealed systematic difference between the recommended cross-sections of both monitoring reactions and provided new cross-section data for formation of 24Na, 27Mg, 43Sc, 44mSc, 44Sc, 46Sc, 47Sc and 48Sc. The cross-sections for the natTi(d,x)46Sc reactions agree very well with recently proposed recommended values.

  5. Complete and incomplete momentum transfer components in the [sup nat]Si([sup 16]O,[ital X]) reaction at 96. 4, 112. 4, and 127. 8 MeV

    SciTech Connect

    Zingarelli, R.A.; Dennis, L.C.; Tiede, M.A.; Kline, R.C.; Kemper, K.W.; Mitchell, S.V. )

    1993-08-01

    Angular distributions and inclusive energy spectra of isotopes with masses 23--41 were measured for the reaction [sup nat]Si([sup 16]O,[ital X]) at bombarding energies of 96.4, 112.4, and 127.8 MeV. Complete and incomplete projectile momentum transfer components of the resulting velocity distributions were separated by kinematic transforms which rely on an angular distribution function fitted to the data using center-of-mass frame symmetry conditions. Characteristics of the extracted complete momentum transfer component spectra, mass distributions, and laboratory frame angular distributions are consistent with fusion-evaporation models. Comparison with the Glas-Mosel parametrization and predictions for the angular momentum barrier to fusion indicate that at 112.4 and 127.8 MeV, competing entrance channel processes, rather than compound nucleus formation limits, restrict the fusion cross section. Spectra and cross sections of the incomplete momentum transfer component are consistent with sequential two-body breakup/fusion calculations.

  6. Complete and incomplete momentum transfer components in the natSi(16O,X) reaction at 96.4, 112.4, and 127.8 MeV

    NASA Astrophysics Data System (ADS)

    Zingarelli, R. A.; Dennis, L. C.; Tiede, M. A.; Kline, R. C.; Kemper, K. W.; Mitchell, S. V.

    1993-08-01

    Angular distributions and inclusive energy spectra of isotopes with masses 23-41 were measured for the reaction natSi(16O,X) at bombarding energies of 96.4, 112.4, and 127.8 MeV. Complete and incomplete projectile momentum transfer components of the resulting velocity distributions were separated by kinematic transforms which rely on an angular distribution function fitted to the data using center-of-mass frame symmetry conditions. Characteristics of the extracted complete momentum transfer component spectra, mass distributions, and laboratory frame angular distributions are consistent with fusion-evaporation models. Comparison with the Glas-Mosel parametrization and predictions for the angular momentum barrier to fusion indicate that at 112.4 and 127.8 MeV, competing entrance channel processes, rather than compound nucleus formation limits, restrict the fusion cross section. Spectra and cross sections of the incomplete momentum transfer component are consistent with sequential two-body breakup/fusion calculations.

  7. Acidic precipitation

    SciTech Connect

    Martin, H.C.

    1987-01-01

    At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).

  8. Metabolomics Suggests That Soil Inoculation with Arbuscular Mycorrhizal Fungi Decreased Free Amino Acid Content in Roots of Durum Wheat Grown under N-Limited, P-Rich Field Conditions

    PubMed Central

    Saia, Sergio; Ruisi, Paolo; Fileccia, Veronica; Di Miceli, Giuseppe; Amato, Gaetano; Martinelli, Federico

    2015-01-01

    Arbuscular mycorrhizal fungi (AMF) have a major impact on plant nutrition, defence against pathogens, a plant’s reaction to stressful environments, soil fertility, and a plant’s relationship with other microorganisms. Such effects imply a broad reprogramming of the plant’s metabolic activity. However, little information is available regarding the role of AMF and their relation to other soil plant growth—promoting microorganisms in the plant metabolome, especially under realistic field conditions. In the present experiment, we evaluated the effects of inoculation with AMF, either alone or in combination with plant growth–promoting rhizobacteria (PGPR), on the metabolome and changes in metabolic pathways in the roots of durum wheat (Triticum durum Desf.) grown under N-limited agronomic conditions in a P-rich environment. These two treatments were compared to infection by the natural AMF population (NAT). Soil inoculation with AMF almost doubled wheat root colonization by AMF and decreased the root concentrations of most compounds in all metabolic pathways, especially amino acids (AA) and saturated fatty acids, whereas inoculation with AMF+PGPR increased the concentrations of such compounds compared to inoculation with AMF alone. Enrichment metabolomics analyses showed that AA metabolic pathways were mostly changed by the treatments, with reduced amination activity in roots most likely due to a shift from the biosynthesis of common AA to γ-amino butyric acid. The root metabolome differed between AMF and NAT but not AMF+PGPR and AMF or NAT. Because the PGPR used were potent mineralisers, and AMF can retain most nitrogen (N) taken as organic compounds for their own growth, it is likely that this result was due to an increased concentration of mineral N in soil inoculated with AMF+PGPR compared to AMF alone. PMID:26067663

  9. Reverse Transcription Cross-Priming Amplification-Nucleic Acid Test Strip for Rapid Detection of Porcine Epidemic Diarrhea Virus.

    PubMed

    Wang, Feng-Xue; Yuan, Dan-Yi; Jin, Ya-Nan; Hu, Lin; Sun, Zhi-Yong; He, Qian; Zhao, Shi-Hua; Zhan, Shu-Bai; Wen, Yong-Jun

    2016-01-01

    Porcine epidemic diarrhea virus (PEDV) is a highly transmissible coronavirus that causes a severe enteric disease particularly in neonatal piglets. In this study, a rapid method for detecting PEDV was developed based on cross-priming amplification and nucleic acid test strip(CPA-NATS). Five primers specific for the N gene sequence of PEDV were used for the cross-priming amplification. Detection of amplification products based on labeled probe primers was conducted with strip binding antibody of labeled markers. The CPA method was evaluated and compared with a PCR method. The reverse transcription CPA system was further optimized for detecting PEDV RNA in clinical specimens. Results showed that the method was highly specific for the detection of PEDV, and had the same sensitivity as PCR, with detection limit of 10(-6) diluted plasmid containing the target gene of PEDV. It was also successfully applied to detecting PEDV in clinical specimens. The reverse transcription CPA-NATS detection system established in this study offers a specific, sensitive, rapid, and simple detection tool for screening PEDV, which can contribute to strategies in the effective control of PEDV in swine. PMID:27090105

  10. Polydimethylsiloxane-Paper Hybrid Lateral Flow Assay for Highly Sensitive Point-of-Care Nucleic Acid Testing.

    PubMed

    Choi, Jane Ru; Liu, Zhi; Hu, Jie; Tang, Ruihua; Gong, Yan; Feng, Shangsheng; Ren, Hui; Wen, Ting; Yang, Hui; Qu, Zhiguo; Pingguan-Murphy, Belinda; Xu, Feng

    2016-06-21

    In nucleic acid testing (NAT), gold nanoparticle (AuNP)-based lateral flow assays (LFAs) have received significant attention due to their cost-effectiveness, rapidity, and the ability to produce a simple colorimetric readout. However, the poor sensitivity of AuNP-based LFAs limits its widespread applications. Even though various efforts have been made to improve the assay sensitivity, most methods are inappropriate for integration into LFA for sample-to-answer NAT at the point-of-care (POC), usually due to the complicated fabrication processes or incompatible chemicals used. To address this, we propose a novel strategy of integrating a simple fluidic control strategy into LFA. The strategy involves incorporating a piece of paper-based shunt and a polydimethylsiloxane (PDMS) barrier to the strip to achieve optimum fluidic delays for LFA signal enhancement, resulting in 10-fold signal enhancement over unmodified LFA. The phenomena of fluidic delay were also evaluated by mathematical simulation, through which we found the movement of fluid throughout the shunt and the tortuosity effects in the presence of PDMS barrier, which significantly affect the detection sensitivity. To demonstrate the potential of integrating this strategy into a LFA with sample-in-answer-out capability, we further applied this strategy into our prototype sample-to-answer LFA to sensitively detect the Hepatitis B virus (HBV) in clinical blood samples. The proposed strategy offers great potential for highly sensitive detection of various targets for wide application in the near future. PMID:27012657

  11. Reverse Transcription Cross-Priming Amplification–Nucleic Acid Test Strip for Rapid Detection of Porcine Epidemic Diarrhea Virus

    PubMed Central

    Wang, Feng-Xue; Yuan, Dan-Yi; Jin, Ya-Nan; Hu, Lin; Sun, Zhi-Yong; He, Qian; Zhao, Shi-Hua; Zhan, Shu-Bai; Wen, Yong-Jun

    2016-01-01

    Porcine epidemic diarrhea virus (PEDV) is a highly transmissible coronavirus that causes a severe enteric disease particularly in neonatal piglets. In this study, a rapid method for detecting PEDV was developed based on cross-priming amplification and nucleic acid test strip(CPA-NATS). Five primers specific for the N gene sequence of PEDV were used for the cross-priming amplification. Detection of amplification products based on labeled probe primers was conducted with strip binding antibody of labeled markers. The CPA method was evaluated and compared with a PCR method. The reverse transcription CPA system was further optimized for detecting PEDV RNA in clinical specimens. Results showed that the method was highly specific for the detection of PEDV, and had the same sensitivity as PCR, with detection limit of 10−6 diluted plasmid containing the target gene of PEDV. It was also successfully applied to detecting PEDV in clinical specimens. The reverse transcription CPA-NATS detection system established in this study offers a specific, sensitive, rapid, and simple detection tool for screening PEDV, which can contribute to strategies in the effective control of PEDV in swine. PMID:27090105

  12. Hydrogen bonding patterns in salts of derivatives of aminopyrimidine and thiobarbituric acid.

    PubMed

    Gomathi, Sundaramoorthy; Nirmalram, Jeyaraman Selvaraj; Muthiah, Packianathan Thomas

    2015-04-01

    Three salts, namely 2-amino-4,6-dimethylpyrimidin-1-ium thiobarbiturate trihydrate (I), 2-amino-4,6-dimethoxypyrimidin-1-ium thiobarbiturate dihydrate (II) and 2,4-diamino-5-(3',4',5'-trimethoxybenzyl)pyrimidin-1-ium thiobarbiturate (III), were synthesized and characterized by IR and X-ray diffraction techniques. The primary interaction between the acid and base happens via N-H...O hydrogen bonds in (II) and (III), and via water-mediated N-H...OW and OW-HW...S in (I). The water molecules present in compound (I) form a (H2O)12 water cluster via water-water interactions. In all three compounds (I)-(III), thiobarbiturate anions form self-complementary pairs with a robust R2(2)(8) motif via a pair of N-H...O/N-H...S hydrogen bonds. They mimic the nucleobase base pairs by utilizing the same groups (thymine/uracil uses N3-H and C4=O8 groups during the formation of Watson-Crick and Hoogsteen base pairs with adenine). Compound (I) forms a water-mediated base pair through N-H...OW hydrogen bonds and forms an R4(2)(12) motif. The formation of N-H...S hydrogen bonds, water-mediated base pairs and water-water interactions in these crystal systems offers scope for these systems to be considered as a model in the study of hydration of nucleobases and water-mediated nucleobase base pairs in macromolecules. PMID:25827367

  13. Physical Chemistry of the H2SO4/HNO3/H2O System: Implications for Polar Stratospheric Clouds.

    PubMed

    Molina, M J; Zhang, R; Wooldridge, P J; McMahon, J R; Kim, J E; Chang, H Y; Beyer, K D

    1993-09-10

    Polar stratospheric clouds (PSCs) play a key role in stratospheric ozone depletion. Surface-catalyzed reactions on PSC particles generate chlorine compounds that photolyze readily to yield chlorine radicals, which in turn destroy ozone very efficiently. The most prevalent PSCs form at temperatures several degrees above the ice frost point and are believed to consist of HNO(3) hydrates; however, their formation mechanism is unclear. Results of laboratory experiments are presented which indicate that the background stratospheric H(2)SO(4)/H(2)O aerosols provide an essential link in this mechanism: These liquid aerosols absorb significant amounts of HNO(3) vapor, leading most likely to the crystallization of nitric acid trihydrate (NAT). The frozen particles then grow to form PSCs by condensation of additional amounts of HNO(3) and H(2)O vapor. Furthermore, reaction probability measurements reveal that the chlorine radical precursors are formed readily at polar stratospheric temperatures not just on NAT and ice crystals, but also on liquid H(2)SO(4) solutions and on solid H(2)SO(4) hydrates. These results imply that the chlorine activation efficiency of the aerosol particles increases rapidly as the temperature approaches the ice frost point regardless of the phase or composition of the particles. PMID:17745351

  14. Physical chemistry of the H2SO4/HNO3/H2O system - Implications for polar stratospheric clouds

    NASA Technical Reports Server (NTRS)

    Molina, M. J.; Zhang, R.; Wooldridge, P. J.; Mcmahon, J. R.; Kim, J. E.; Chang, H. Y.; Beyer, K. D.

    1993-01-01

    Polar stratospheric clouds (PSCs) play a key role in stratospheric ozone depletion. Surface-catalyzed reactions on PSC particles generate chlorine compounds that photolyze readily to yield chlorine radicals, which in turn destroy ozone very efficiently. The most prevalent PSCs form at temperatures several degrees above the ice frost point and are believed to consist of HNO3 hydrates; however, their formation mechanism is unclear. Results of laboratory experiments are presented which indicate that the background stratospheric H2SO4/H2O aerosols provide an essential link in this mechanism: These liquid aerosols absorb significant amounts of HNO3 vapor, leading most likely to the crystallization of nitric acid trihydrate (NAT). The frozen particles then grow to form PSCs by condensation of additional amounts of HNO3 and H2O vapor. Furthermore, reaction probability measurements reveal that the chlorine radical precursors are formed readily at polar stratospheric temperatures not just on NAT and ice crystals, but also on liquid H2SO4 solutions and on solid H2SO4 hydrates. These results imply that the chlorine activation efficiency of the aerosol particles increases rapidly as the temperature approaches the ice frost point regardless of the phase or composition of the particles.

  15. 9+ Years of CALIOP PSC Data: An Evolving Climatology

    NASA Technical Reports Server (NTRS)

    Pitts, Michael C.; Poole, Lamont R.

    2015-01-01

    Polar stratospheric clouds (PSCs) play key roles in the springtime chemical depletion of ozone at high latitudes. PSC particles provide sites for heterogeneous chemical reactions that transform stable chlorine and bromine reservoir species into highly reactive ozone-destructive forms. Furthermore, large nitric acid trihydrate (NAT) PSC particles can irreversibly redistribute odd nitrogen through gravitational sedimentation, which prolongs the ozone depletion process by slowing the reformation of the stable chlorine reservoirs. However, there are still significant gaps in our understanding of PSC processes, particularly concerning the details of NAT particle formation. Spaceborne observations from the CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) lidar on the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) satellite are providing a rich new dataset for studying PSCs on unprecedented vortex-wide scales. In this paper, we examine the vertical and spatial distribution of PSCs in the Antarctic and Arctic on vortex-wide scales for entire PSC seasons over the more than nine-year data record.

  16. Stratospheric cloud observations during formation of the Antarctic ozone hole in 1989

    SciTech Connect

    Hofmann, D.J.; Deshler, T. )

    1991-02-20

    The results of six balloon flights at McMurdo Station, Antarctica, under varying temperature conditions, are used in a study of polar stratospheric clouds during September 1989. A new particle counter, with size resolution in the 0.5 {mu}m radius region, indicated that size distributions observed in the clouds were bimodal. Mode radii ranging from 0.05 to 0.10 {mu}m were observed for the small particle mode, representing the sulfate layer or condensational growth enhancements of it. Mode radii generally ranged from 1.5 to 3.5 {mu}m for the large particle mode at concentrations 3 to 4 orders of magnitude lower than the small particle mode. The large particle mode, when observed at temperatures above the water ice point, is believed to be the result of nitric acid trihydrate (NAT) condensation on larger particles of the sulfate layer. In this case the HNO{sub 3} condensed mass mixing ratios were 1 to 5 ppbv for most of the cloud layers. Generally, the large particle NAT concentrations were higher in the lower stratosphere, indicating the redistribution of HNO{sub 3} through particle sedimentation. On several occasions, distributions were observed with mode radii as high as 7 {mu}m, and correspondingly large inferred mass, indicating water ice clouds in the 12 to 15 km region. On other occasions, absence of such clouds at very low temperatures inferred water vapor mixing ratios of less than 3 ppmv.

  17. Salicylic acids

    PubMed Central

    Hayat, Shamsul; Irfan, Mohd; Wani, Arif; Nasser, Alyemeni; Ahmad, Aqil

    2012-01-01

    Salicylic acid is well known phytohormone, emerging recently as a new paradigm of an array of manifestations of growth regulators. The area unleashed yet encompassed the applied agriculture sector to find the roles to strengthen the crops against plethora of abiotic and biotic stresses. The skipped part of integrated picture, however, was the evolutionary insight of salicylic acid to either allow or discard the microbial invasion depending upon various internal factors of two interactants under the prevailing external conditions. The metabolic status that allows the host invasion either as pathogenesis or symbiosis with possible intermediary stages in close systems has been tried to underpin here. PMID:22301975

  18. Influenza A virus drift variants reduced the detection sensitivity of a commercial multiplex nucleic acid amplification assay in the season 2014/15.

    PubMed

    Huzly, Daniela; Korn, Klaus; Bierbaum, Sibylle; Eberle, Björn; Falcone, Valeria; Knöll, Antje; Steininger, Philipp; Panning, Marcus

    2016-09-01

    The influenza season 2014/15 was dominated by drift variants of influenza A(H3N2), which resulted in a reduced vaccine effectiveness. It was not clear if the performance of commercial nucleic-acid-based amplification (NAT) assays for the detection of influenza was affected. The purpose of this study was to perform a real-life evaluation of two commercial NAT assays. During January-April 2015, we tested a total of 665 samples from patients with influenza-like illness using the Fast Track Diagnostics Respiratory pathogens 21, a commercial multiplex kit, (cohorts 1 and 2, n = 563 patients) and the Xpert Flu/RSV XC assay (cohort 3, n = 102 patients), a single-use cartridge system. An in-house influenza real-time RT-PCR (cohort 1) and the RealStar Influenza RT-PCR 1.0 Kit (cohort 2 and 3) served as reference tests. Compared to the reference assay, an overall agreement of 95.9 % (cohort 1), 95 % (cohort 2), and 98 % (cohort 3) was achieved. A total of 24 false-negative results were observed using the Fast Track Diagnostics Respiratory pathogens 21 kit. No false-negative results occurred using the Xpert Flu/RSV XC assay. The Fast Track Diagnostics Respiratory pathogens 21 kit and the Xpert Flu/RSV XC assay had sensitivities of 90.7 % and 100 % and specificities of 100 % and 94.1 %, respectively, compared to the RealStar 1.0 kit. Upon modification of the Fast Track Diagnostics Respiratory pathogens 21 kit, the sensitivity increased to 97.3 %. Influenza virus strains circulating during the 2014/15 season reduced the detection sensitivity of a commercial NAT assay, and continuous monitoring of test performance is therefore necessary. PMID:27316440

  19. Folic acid

    MedlinePlus

    ... disease called vitiligo, and an inherited disease called Fragile-X syndrome. It is also used for reducing harmful side ... to blood clots (ischemic stroke). Inherited disease called Fragile-X syndrome.Taking folic acid by mouth does not improve ...

  20. Acid rain

    SciTech Connect

    Not Available

    1984-06-01

    An overview is presented of acid rain and the problems it causes to the environment worldwide. The acidification of lakes and streams is having a dramatic effect on aquatic life. Aluminum, present in virtually all forest soils, leaches out readily under acid conditions and interferes with the gills of all fish, some more seriously than others. There is evidence of major damage to forests in European countries. In the US, the most severe forest damage appears to be in New England, New York's Adirondacks, and the central Appalachians. This small region is part of a larger area of the Northeast and Canada that appears to have more acid rainfall than the rest of the country. It is downwind from major coal burning states, which produce about one quarter of US SO/sub 2/ emissions and one sixth of nitrogen oxide emissions. Uncertainties exist over the causes of forest damage and more research is needed before advocating expensive programs to reduce rain acidity. The President's current budget seeks an expansion of research funds from the current $30 million per year to $120 million.

  1. Formic acid

    Integrated Risk Information System (IRIS)

    Formic acid ; CASRN 64 - 18 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effect

  2. Selenious acid

    Integrated Risk Information System (IRIS)

    Selenious acid ; CASRN 7783 - 00 - 8 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic E

  3. Benzoic acid

    Integrated Risk Information System (IRIS)

    Benzoic acid ; CASRN 65 - 85 - 0 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Effec

  4. Trichloroacetic acid

    Integrated Risk Information System (IRIS)

    Trichloroacetic acid ( TCA ) ; CASRN 76 - 03 - 9 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonca

  5. Dichloroacetic acid

    Integrated Risk Information System (IRIS)

    Dichloroacetic acid ; CASRN 79 - 43 - 6 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  6. Acrylic acid

    Integrated Risk Information System (IRIS)

    Acrylic acid ( CASRN 79 - 10 - 7 ) Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  7. Cacodylic acid

    Integrated Risk Information System (IRIS)

    Cacodylic acid ; CASRN 75 - 60 - 5 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic Eff

  8. Phosphoric acid

    Integrated Risk Information System (IRIS)

    Phosphoric acid ; CASRN 7664 - 38 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogenic

  9. Stearic Acid

    ERIC Educational Resources Information Center

    Young, Jay A.

    2004-01-01

    A chemical laboratory information profile (CLIP) is presented for the chemical, stearic acid. The profile lists the chemical's physical and harmful characteristics, exposure limits, and symptoms of major exposure, for the benefit of teachers and students, who use the chemical in the laboratory.

  10. Deletion of SHATI/NAT8L decreases the N-acetylaspartate content in the brain and induces behavioral deficits, which can be ameliorated by administering N-acetylaspartate.

    PubMed

    Toriumi, Kazuya; Mamiya, Takayoshi; Song, Ziyu; Honjo, Tatsuki; Watanabe, Hiroyuki; Tanaka, Junko; Kondo, Mizuki; Mouri, Akihiro; Kim, Hyoung-Chun; Nitta, Atsumi; Fukushima, Takeshi; Nabeshima, Toshitaka

    2015-11-01

    We previously identified a novel molecule "SHATI/NAT8L" that exerts an inhibitory effect on methamphetamine (METH)-induced behavioral deficits. Recently, it has been reported that SHATI might function as an aspartate N-acetyltransferase, which synthesizes N-acetylaspartate (NAA) in vitro. However, whether SHATI actually synthesizes NAA in vivo in the brain is still unclear. In this study, we found that both Shati-deleted mice showed significantly lower NAA levels in all brain areas than wild-type (Shati(+/+)) mice using HPLC and fluorescence detection, suggesting that SHATI regulates NAA content in the brain. Next, we measured the levels of monoamines and their metabolites in the adult mouse brain and found that the activities of monoaminergic systems were altered in Shati(-/-) mice. In particular, dopaminergic turnover increased in the nucleus accumbens (NAc) in Shati(-/-) mice, suggesting activation of the dopaminergic system. In fact, basal level of extracellular dopamine, and METH-induced dopamine release in the NAc of Shati(-/-) mice was significantly higher than that of Shati(+/+) and Shati(+/-) mice, which is consistent with findings that Shati(-/-) mice showed enhanced hyperlocomotion induced by METH. Moreover, in the forced swimming test, Shati-deleted mice showed a shortened immobility time, which was improved by intracerebroventricular (i.c.v.) administration of NAA prior to the test in Shati(+/-) but not in Shati(-/-) mice. The i.c.v. preinjection of NAA inhibited dopamine release after high K(+) stimulation in the NAc of Shati(+/+) and Shati(+/-) mice, but not Shati(-/-) mice. These results suggested that the behavioral deficits in Shati-deleted mice were caused by dopaminergic abnormality via deprivation of NAA. PMID:26361739

  11. Hepatic and renal toxicities of indomethacin acid, salt form and complexed forms with hydroxypropyl-β-cyclodextrin on Wistar rats after oral administration.

    PubMed

    Ribeiro-Rama, Ana Cristina; Figueiredo, Isabel Vitória; Veiga, Francisco José; Castel-Branco, Maria Margarida; Cabrita, António M Silvério; Caramona, Maria Margarida

    2011-10-01

    Indomethacin (IM), a non-steroidal anti-inflammatory drug, has the capacity to induce hepatic and renal injuries when administrated systemically. The aim of this study is to assess the IM absorption from complexed forms when orally administered to rats, by means of a comparative evaluation of its capacity to induce hepatic and renal injury in different forms, namely IM acid, IM sodium salt or IM complexed with hydroxypropyl-β-cyclodextrin (HP-β-CD), using freeze- and spray-drying methods. A total of 135 Wistar rats weighing 224.4 ± 62.5 g were put into 10 groups. They were allowed free access to water but were maintained on fast for 18 h before the first administration until the end of the experiment. Water and HP-β-CD (control groups) and IM acid form, IM trihydrated-sodium-salt and IM-HP-β-CD spray- and freeze-dried, at normal and toxic doses (test groups), were orally administered once/day for 3 days. Seventy-two hours after the first administration, the animals were sacrificed and a fragment of the liver and one kidney were collected and prepared for histopathological evaluation. Lesion indexes (rated 0/4 for liver and 0/3 for kidney) were developed and the type of injury scored according to the severity of damage. A statistical analysis of the severity and incidence of lesions was carried out. Animals administered with IM complexed forms showed similar hepatic and renal lesions, both in toxic and therapeutic doses, when compared with those observed in animals administered with IM acid or salt forms. This suggests that under the present experimental conditions, IM is equally absorbed from the gastrointestinal tract, independently of the administered IM form. PMID:21077942

  12. Crystal structures of tetra-methyl-ammonium (2,2'-bi-pyridine)-tetra-cyanidoferrate(III) trihydrate and poly[[(2,2'-bi-pyridine-κ(2) N,N')di-μ2-cyanido-dicyanido(μ-ethyl-enedi-amine)(ethyl-enedi-amine-κ(2) N,N')-cadmium(II)iron(II)] monohydrate].

    PubMed

    Chanthee, Songwuit; Punyain, Wikorn; Namuangrak, Supawadee; Chainok, Kittipong

    2016-05-01

    The crystal structures of the building block tetra-methyl-ammonium (2,2'-bi-pyridine-κ(2) N,N')tetra-cyanidoferrate(III) trihydrate, [N(CH3)4][Fe(CN)4(C10H8N2)]·3H2O, (I), and a new two-dimensional cyanide-bridged bimetallic coordination polymer, poly[[(2,2'-bi-pyridine-κ(2) N,N')di-μ2-cyanido-dicyanido(μ-ethyl-enedi-amine-κ(2) N:N')(ethyl-enedi-amine-κ(2) N,N')cadmium(II)iron(II)] monohydrate], [CdFe(CN)4(C10H8N2)(C2H8N2)2]·H2O, (II), are reported. In the crystal of (I), pairs of [Fe(2,2'-bipy)(CN)4](-) units (2,2'-bipy is 2,2'-bi-pyri-dine) are linked together through π-π stacking between the pyridyl rings of the 2,2'-bipy ligands to form a graphite-like structure parallel to the ab plane. The three independent water mol-ecules are hydrogen-bonded alternately with each other, forming a ladder chain structure with R 4 (4)(8) and R 6 (6)(12) graph-set ring motifs, while the disordered [N(CH3)4](+) cations lie above and below the water chains, and the packing is stabilized by weak C-H⋯O hydrogen bonds. The water chains are further linked with adjacent sheets into a three-dimensional network via O-H⋯O hydrogen bonds involving the lattice water mol-ecules and the N atoms of terminal cyanide groups of the [Fe(2,2'-bipy)(CN)4](-) building blocks, forming an R 4 (4)(12) ring motif. Compound (II) features a two-dimensional {[Fe(2,2'-bipy)(CN)4Cd(en)2]} n layer structure (en is ethyl-enedi-amine) extending parallel to (010) and constructed from {[Fe(2,2'-bipy)(CN)4Cd(en)]} n chains inter-linked by bridging en ligands at the Cd atoms. Classical O-H⋯N and N-H⋯O hydrogen bonds involving the lattice water mol-ecule and N atoms of terminal cyanide groups and the N-H groups of the en ligands are observed within the layers. The layers are further connected via π-π stacking inter-actions between adjacent pyridine rings of the 2,2'-bipy ligands, completing a three-dimensional supra-molecular structure. PMID:27308032

  13. Hydroxycarboxylic acids and salts

    DOEpatents

    Kiely, Donald E; Hash, Kirk R; Kramer-Presta, Kylie; Smith, Tyler N

    2015-02-24

    Compositions which inhibit corrosion and alter the physical properties of concrete (admixtures) are prepared from salt mixtures of hydroxycarboxylic acids, carboxylic acids, and nitric acid. The salt mixtures are prepared by neutralizing acid product mixtures from the oxidation of polyols using nitric acid and oxygen as the oxidizing agents. Nitric acid is removed from the hydroxycarboxylic acids by evaporation and diffusion dialysis.

  14. Microphysical properties of synoptic-scale polar stratospheric clouds: in situ measurements of unexpectedly large HNO3-containing particles in the Arctic vortex

    NASA Astrophysics Data System (ADS)

    Molleker, S.; Borrmann, S.; Schlager, H.; Luo, B.; Frey, W.; Klingebiel, M.; Weigel, R.; Ebert, M.; Mitev, V.; Matthey, R.; Woiwode, W.; Oelhaf, H.; Dörnbrack, A.; Stratmann, G.; Grooß, J.-U.; Günther, G.; Vogel, B.; Müller, R.; Krämer, M.; Meyer, J.; Cairo, F.

    2014-10-01

    In January 2010 and December 2011, synoptic-scale polar stratospheric cloud (PSC) fields were probed during seven flights of the high-altitude research aircraft M-55 Geophysica within the RECONCILE (Reconciliation of essential process parameters for an enhanced predictability of Arctic stratospheric ozone loss and its climate interaction) and the ESSenCe (ESSenCe: ESA Sounder Campaign) projects. Particle size distributions in a diameter range between 0.46 and 40μm were recorded by four different optical in situ instruments. Three of these particle instruments are based on the detection of forward-scattered light by single particles. The fourth instrument is a grayscale optical array imaging probe. Optical particle diameters of up to 35μm were detected with particle number densities and total particle volumes exceeding previous Arctic measurements. Also, gas-phase and particle-bound NOy was measured, as well as water vapor concentrations. The optical characteristics of the clouds were measured by the remote sensing lidar MAL (Miniature Aerosol Lidar) and by the in situ backscatter sonde MAS (Multiwavelength Aerosol Scatterometer), showing the synoptic scale of the encountered PSCs. The particle mode below 2μm in size diameter has been identified as supercooled ternary solution (STS) droplets. The PSC particles in the size range above 2μm in diameter are considered to consist of nitric acid hydrates, and the particles' high HNO3 content was confirmed by the NOy instrument. Assuming a particle composition of nitric acid trihydrate (NAT), the optically measured size distributions result in particle-phase HNO3 mixing ratios exceeding available stratospheric values. Therefore the measurement uncertainties concerning probable overestimations of measured particle sizes and volumes are discussed in detail. We hypothesize that either a strong asphericity or an alternate particle composition (e.g., water ice coated with NAT) could explain our observations. In particular

  15. ERBE S10 MFOV SF NAT

    Atmospheric Science Data Center

    2016-06-09

    ... product contains data which have been averaged to a 2.5 grid scale. The S-10 contains data which have been averaged to 5.0 or 10.0 grid scale. Projection: Gridding is an equal-angle projection of 2.5 X 2.5 ...

  16. ERBE S10 WFOV SF NAT

    Atmospheric Science Data Center

    2016-06-13

    ... scanner instruments on board the NOAA-9 and NOAA-10 satellites provide global coverage, while the ERBE scanner instrument onboard ... have 136 degree FOV on ERBS and 126 degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  17. ERBE S10 WFOV NF NAT

    Atmospheric Science Data Center

    2016-06-09

    ... scanner instruments on board the NOAA-9 and NOAA-10 satellites provide global coverage, while the ERBE scanner instrument onboard ... have 136 degree FOV on ERBS and 126 degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  18. ERBE S10N WFV NF NAT

    Atmospheric Science Data Center

    2016-06-13

    ... scanner instruments on board the NOAA-9 and NOAA-10 satellites provide global coverage, while the ERBE scanner instrument onboard ... have 136 degree FOV on ERBS and 126 degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  19. ERBE S10N WFV SF NAT

    Atmospheric Science Data Center

    2016-06-14

    ... scanner instruments on board the NOAA-9 and NOAA-10 satellites provide global coverage, while the ERBE scanner instrument onboard ... have 136 degree FOV on ERBS and 126 degree FOV on the NOAA satellites. The MFOV instruments have footprints of approximately 5 geocentric ...

  20. Heterogeneous reactions of chlorine nitrate and hydrogen chloride on type I polar stratospheric clouds

    SciTech Connect

    Mingtaun Leu; Moore, S.B.; Keyser, L.F. )

    1991-10-03

    The heterogeneous reactions ClONO{sub 2} + NCl {yields} Cl{sub 2} + NHO{sub 3} (1) and ClONO{sub 2} + H{sub 2}O {yields} HOCl + HNO{sub 3} (2) on vapor-deposited NHO{sub 3}-H{sub 2}O ice substrates have been investigated at 196 K by using a fast-flow reactor coupled with a quadrupole mass spectrometer. The reaction probability for (1) is 0.10 {plus minus} 0.02 and independent of both the HNO{sub 3} and HCl concentrations in the substrate compositions studied. For (2), the reaction probability is approximately 1 {times} 10{sup {minus}5} near 53.8 wt% HNO{sub 3}, the composition of pure nitric acid trihydrate (NAT), and is about 1 {times} 10{sup {minus}3} at 46 wt% HNO{sub 3}. The sticking coefficient of HCl on these substrates was also found to be a strong function of the substrate composition, ranging from about 2 {times} 10{sup {minus}5} at NAT composition to 6 {times} 10{sup {minus}3} at 45 wt% HNO{sub 3}. The HNO{sub 3}-H{sub 2}O ice substrates were found to have large internal surface areas, and corrections for gas-phase diffusion within the porous ices were applied to observed loss rates. The large decrease in the HCl sticking coefficient and the reaction probability for (2) as the composition of pure NAT is approached from the water-enriched side can be semiquantatively explained in terms of a simple two-solid-phase model. Finally, the relation of these results to the depletion of polar ozone is discussed.

  1. 3,2'-Dimethyl-4-aminobiphenyl-DNA adduct formation in tumor target and nontarget organs of rapid and slow acetylator Syrian hamsters cogenic at the NAT2 locus.

    PubMed

    Feng, Y; Jiang, W; Deitz, A C; Hein, D W

    1996-10-01

    DNA adduct formation is an important step in initiation of the carcinogenic process. 3,2'-Dimethyl-4-aminobiphenyl (DMABP) is a well-documented multiorgan carcinogenic aromatic amine in rodents. In the present study, DMABP-DNA adduct levels were measured in rapid (Bio. 82.73/H-Pat(r)) and slow (Bio. 82.73/H-Pat(s)) acetylator Syrian hamsters congenic at the NAT2 locus following a single injection of 33 or 100 mg/kg body wt DMABP. Two DNA adducts, N-(deoxyguanosin-8-yl)-DMABP and 5-(deoxyguanosin-N2-yl)-DMABP, were identified and quantitated by 32P-postlabeling assay. After injection of 33 mg/kg, DMABP-DNA adducts were detected in urinary bladder at 6, 18, 24, and 48 hr with adduct levels increasing up to 48 hr postinjection. DMABP-DNA adducts were not detected in liver, colon, and heart. After injection of 100 mg/kg, DMABP-DNA adducts were detected in urinary bladder, liver, prostate, colon, and heart at 48 hr postinjection. DMABP-DNA adduct levels were significantly higher in urinary bladder (primary tumor target organ) than in the other organs of both rapid and slow acetylator congenic hamsters. N-(deoxyguanosin-8-yl)-DMABP levels were significantly higher in liver and prostate than in colon and heart of rapid and slow acetylator congenic hamsters, whereas 5-(deoxyguanosin-N2-yl)-DMABP levels were significantly higher in prostate than in colon and heart of rapid and slow acetylator congenic hamsters. DMABP-DNA adduct levels in each tissue examined did not differ significantly between rapid and slow acetylator hamsters following either 33 or 100 mg/kg injection. The tissue-dependent differences in DMABP-DNA adduct levels observed in the Syrian hamster differ from those reported in the rat and are consistent with previous studies that show DMABP induces primarily urinary bladder tumors in the Syrian hamster. PMID:8887447

  2. Treatment of cytomegalovirus infection and disease pre- and post-quantitative nucleic acid test standardization: does use of a more sensitive assay lead to longer treatment duration?

    PubMed

    Dioverti, M Veronica; Lahr, Brian; Razonable, Raymund R

    2016-02-01

    Quantitative cytomegalovirus (CMV) nucleic acid testing (NAT) has been standardized using the World Health Organization (WHO) international calibration standard. A new FDA-approved WHO-calibrated assay (CA) was found to be more sensitive than a laboratory-developed test (LDT). We hypothesized that monitoring therapeutic response using a more sensitive assay may lead to longer antiviral therapy in solid organ and hematopoietic stem cell transplant patients with CMV infection. We reviewed transplant patients with CMV disease retrospectively, and divided them into two groups: those diagnosed and managed based on LDT and those managed using WHO-CA. Compared to patients monitored by LDT, the time to reach an undetectable viral load was significantly longer in the group monitored by the WHO-CA. However, a trend toward shorter duration of antiviral treatment was observed (median, 34 vs. 41 d; p = 0.058), with earlier discontinuation of induction antiviral therapy upon reaching undetectable viral load using WHO-CA (11 vs. 18 d; p = 002). We concluded that despite using a more sensitive CMV NAT, the total duration of antiviral treatment was not significantly prolonged in transplant patients with CMV infection and disease. Relapse rates did not differ between the two groups. PMID:26589482

  3. Methylmalonic acid blood test

    MedlinePlus

    ... acid is a substance produced when proteins, called amino acids, in the body break down. The health care ... Cederbaum S, Berry GT. Inborn errors of carbohydrate, ammonia, amino acid, and organic acid metabolism. In: Gleason CA, Devaskar ...

  4. Folic acid - test

    MedlinePlus

    Folic acid is a type of B vitamin. This article discusses the test to measure the amount of folic acid in the blood. ... that may interfere with test results, including folic acid supplements. Drugs that can decrease folic acid measurements ...

  5. Uric acid urine test

    MedlinePlus

    The uric acid urine test measures the level of uric acid in urine. Uric acid level can also be checked using a blood ... help determine the cause of a high uric acid level in the blood. It may also be ...

  6. Methylmalonic acid blood test

    MedlinePlus

    The methylmalonic acid blood test measures the amount of methylmalonic acid in the blood. ... Methylmalonic acid is a substance produced when proteins, called amino acids, in the body break down. The health care ...

  7. Folic Acid and Pregnancy

    MedlinePlus

    ... 5 Things to Know About Zika & Pregnancy Folic Acid and Pregnancy KidsHealth > For Parents > Folic Acid and ... before conception and during early pregnancy . About Folic Acid Folic acid, sometimes called folate, is a B ...

  8. Rates and mechanisms of conversion of ice nanocrystals to hydrates of HCl and HBr: acid diffusion in the ionic hydrates.

    PubMed

    Devlin, J Paul; Gulluru, Dheeraj B; Buch, Victoria

    2005-03-01

    This FTIR study focuses on solid-state chemistry associated with formation and interconversion of the ionic HX (X = Cl, Br) hydrates. Kinetic data are reported for conversions of ice nanocrystal arrays exposed to the saturation pressure of the acids in the 110 approximately 125 K range. The product is amorphous acid dihydrate in the case of HBr, and amorphous monohydrate for HCl. The rate-determining step is identified as HX diffusion through the hydrate product crust toward the interfacial reaction zone, rather than diffusion through ice, as commonly believed. Slowing of the conversion process is thus observed with increasing thickness of the crust. The diffusion coefficient (D(e)) and activation energy values for HX diffusion through the hydrates were evaluated with the help of the shrinking-core model. Hydrate crystallization occurs as a separate step, upon heating above 130 K. Subsequently, rates of reversible transitions between crystal di- and monohydrates were observed upon exposure to acid vapor and acid evacuation. In conversion from di- to monohydrate, the rate slows after fast formation of several layers; subsequently, diffusion through the product crust appears to be the rate-controlling step. The activation energy for HBr diffusion through crystal dihydrate is found to be significantly higher than that for the amorphous analogue. Conjecture is offered for a molecular mechanism of HX transport through the crystal hydrate, based on (i) spectroscopic/computational evidence for the presence of molecular HX bonded to X(-) in each of the ionic hydrate phases and (ii) the relative E(a) values found for HBr and HCl diffusion. Monte Carlo modeling suggests acid transport to the reaction zone along boundaries between "nanocrystallites" generated by multiple hydrate nucleation events at the particle surfaces. The reverse conversion, of crystalline monohydrate particles to the dihydrate phase, as well as dihydrate to trihydrate, displays nearly constant rate

  9. Understanding Acid Rain

    ERIC Educational Resources Information Center

    Damonte, Kathleen

    2004-01-01

    The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…

  10. New bioactive fatty acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to the new compounds, 7,10-dihydroxy-8(E)-octad...

  11. New Bioactive Fatty Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to new compounds, 7,10-dihydroxy-8(E)-octadecen...

  12. Measurement of isomeric yield ratios of 197m,gPt and 190m2,g+m1Ir from the 198Pt(γ,n) and natPt(γ,xn1p) reactions induced by 55-, 60-, and 65-MeV bremsstrahlung

    NASA Astrophysics Data System (ADS)

    Kye, Yong-Uk; Shin, Sung-Gyun; Cho, Moo-Hyun; Kim, Kyung Sook; Namkung, Won; Kim, Guinyun; Kim, Kwangsoo; Kang, Yeong-Rok; Lee, Man-Woo; Yang, Sung-Chul; Nguyen, Van Do; Pham, Duc Khue; Kim, Tien Thanh; Naik, Haladhara

    2015-05-01

    We have measured the isomeric yield ratios of 197m,gPt from the 198Pt(γ,n) reaction and 190m2,g+m1Ir from the natPt(γ,xn1p) reaction, induced with the bremsstrahlung end-point energies of 55-, 60-, and 65-MeV. The measurements were carried out by the activation method in combination with the direct γ-spectrometry. The experiments were performed at the 100 MeV electron linac of the Pohang Accelerator Laboratory (PAL). The obtained results at 55-, 60- and 65-MeV for the 197m,gPt from the 198Pt(γ,n) reaction are 0.166 ± 0.012, 0.174 ± 0.011, and 0.175 ± 0.011, whereas for the 190m2,g+m1Ir from the natPt(γ,xn1p) reaction are 0.072 ± 0.006, 0.084 ± 0.006 and 0.087 ± 0.006, respectively. The present results are measured for the first time over the investigated energy range. The present data are compared with the similar literature data at lower energy to examine the role of excitation energy.

  13. Bioactive Fatty Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxygenated fatty acids are useful as specialty chemicals, plasticizers, and biomedicals. Microbial enzymes convert fatty acids to mono-, di-, and trihydroxy fatty acid products. Among them, Bacillus megaterium ALA2 converted n-6 and n-3 PUFAs to many new oxygenated fatty acids. Linoleic acid was ...

  14. Uric acid test (image)

    MedlinePlus

    Uric acid urine test is performed to check for the amount of uric acid in urine. Urine is collected over a 24 ... testing. The most common reason for measuring uric acid levels is in the diagnosis or treatment of ...

  15. Amino Acid Metabolism Disorders

    MedlinePlus

    ... defects & other health conditions > Amino acid metabolism disorders Amino acid metabolism disorders E-mail to a friend Please ... baby’s newborn screening may include testing for certain amino acid metabolism disorders. These are rare health conditions that ...

  16. Plasma amino acids

    MedlinePlus

    Amino acids blood test ... types of methods used to determine the individual amino acid levels in the blood. ... test is done to measure the level of amino acids in the blood. An increased level of a ...

  17. Stomach acid test

    MedlinePlus

    Gastric acid secretion test ... of the cells in the stomach to release acid. The stomach contents are then removed and analyzed. ... 3.5). These numbers are converted to actual acid production in units of milliequivalents per hour in ...

  18. Azelaic Acid Topical

    MedlinePlus

    Azelaic acid gel is used to clear the bumps, lesions, and swelling caused by rosacea (a skin disease that ... redness, flushing, and pimples on the face). Azelaic acid cream is used to treat acne. Azelaic acid ...

  19. Facts about Folic Acid

    MedlinePlus

    ... Information For... Media Policy Makers Facts About Folic Acid Language: English Español (Spanish) Recommend on Facebook Tweet ... of the baby's brain and spine. About folic acid Folic acid is a B vitamin. Our bodies ...

  20. Acid Lipase Disease

    MedlinePlus

    ... Awards Enhancing Diversity Find People About NINDS NINDS Acid Lipase Disease Information Page Synonym(s): Cholesterol Ester Storage ... Trials Related NINDS Publications and Information What is Acid Lipase Disease ? Acid lipase disease or deficiency occurs ...

  1. What role do type I polar stratospheric cloud and aerosol parameterizations play in modelled lower stratospheric chlorine activation and ozone loss?

    NASA Astrophysics Data System (ADS)

    Sessler, J.; Good, P.; MacKenzie, A. R.; Pyle, J. A.

    1996-12-01

    The chlorine activation and subsequent ozone loss of the northern winter lower stratosphere have been modelled using different schemes for type I polar stratospheric clouds (PSCs) and sulphate aerosols. Type I PSCs were assumed to consist of either nitric acid trihydrate (NAT) at equilibrium, supercooled ternary solutions (STS) at equilibrium, or to follow a hysteresis cycle between frozen and liquid particles depending on the temperature history. The sulphate aerosol was assumed to be present as either liquid binary H2SO4/H2O aerosol (LBA) or as solid sulphuric acid tetrahydrate (SAT). Our box model integrations show that NAT and STS, representing the upper and lower limits of lower stratospheric chlorine activation, respectively, appear to destroy ozone equally efficiently after a cold PSC event (Tmin ≤ 190K at 50 mbar). For higher minimum temperatures, up to the equilibrium NAT point, there is significantly more ozone loss in the NAT scheme than in the STS scheme. On NAT, chlorine is activated directly by ClONO2 + HCl → 2Cl + HNO3, whereas on STS, indirect activation by ClONO2 + H2O → HOCl + HNO3 followed by HOCl + HCl → 2Cl + H2O, dominates. During the processing period, the indirect activation on STS will produce a temporary peak in HOCl. Box model integrations also show that direct chlorine activation is faster on SAT than on LBA, yielding significantly more ozone loss in air parcels which remain below the SAT melting point (215-220 K). Our single-layer chemical transport model simulations (θ = 465K) of the lower stratospheric chlorine activation during Arctic winter 1994/1995 show that chlorine is activated more quickly on NAT than on STS. However, in mid December 1994, when temperatures are low enough for substantial STS particle growth, maximum active chlorine becomes similar in both schemes and remains similar until the end of January 1995. A model integration which includes SAT produces up to 200 parts per trillion by volume more ClOx, inside

  2. Atmospheric chemistry of a 33-34 hour old volcanic cloud from Hekla Volcano (Iceland): Insights from direct sampling and the application of chemical box modeling

    NASA Astrophysics Data System (ADS)

    Rose, William I.; Millard, Genevieve A.; Mather, Tamsin A.; Hunton, Donald E.; Anderson, Bruce; Oppenheimer, Clive; Thornton, Brett F.; Gerlach, Terrence M.; Viggiano, Albert A.; Kondo, Yutaka; Miller, Thomas M.; Ballenthin, John O.

    2006-10-01

    On 28 February 2000, a volcanic cloud from Hekla volcano, Iceland, was serendipitously sampled by a DC-8 research aircraft during the SAGE III Ozone Loss and Validation Experiment (SOLVE I). It was encountered at night at 10.4 km above sea level (in the lower stratosphere) and 33-34 hours after emission. The cloud is readily identified by abundant SO2 (≤1 ppmv), HCl (≤70 ppbv), HF (≤60 ppbv), and particles (which may have included fine silicate ash). We compare observed and modeled cloud compositions to understand its chemical evolution. Abundances of sulfur and halogen species indicate some oxidation of sulfur gases but limited scavenging and removal of halides. Chemical modeling suggests that cloud concentrations of water vapor and nitric acid promoted polar stratospheric cloud (PSC) formation at 201-203 K, yielding ice, nitric acid trihydrate (NAT), sulfuric acid tetrahydrate (SAT), and liquid ternary solution H2SO4/H2O/HNO3 (STS) particles. We show that these volcanically induced PSCs, especially the ice and NAT particles, activated volcanogenic halogens in the cloud producing >2 ppbv ClOx. This would have destroyed ozone during an earlier period of daylight, consistent with the very low levels of ozone observed. This combination of volcanogenic PSCs and chlorine destroyed ozone at much faster rates than other PSCs that Arctic winter. Elevated levels of HNO3 and NOy in the cloud can be explained by atmospheric nitrogen fixation in the eruption column due to high temperatures and/or volcanic lightning. However, observed elevated levels of HOx remain unexplained given that the cloud was sampled at night.

  3. Atmospheric chemistry of a 33-34 hour old volcanic cloud from Hekla Volcano (Iceland): Insights from direct sampling and the application of chemical box modeling

    USGS Publications Warehouse

    Rose, William I., Jr.; Millard, G.A.; Mather, T.A.; Hunton, D.E.; Anderson, B.; Oppenheimer, C.; Thornton, B.F.; Gerlach, T.M.; Viggiano, A.A.; Kondo, Y.; Miller, T.M.; Ballenthin, J.O.

    2006-01-01

    On 28 February 2000, a volcanic cloud from Hekla volcano, Iceland, was serendipitously sampled by a DC-8 research aircraft during the SAGE III Ozone Loss and Validation Experiment (SOLVE I). It was encountered at night at 10.4 km above sea level (in the lower stratosphere) and 33-34 hours after emission. The cloud is readily identified by abundant SO2 (???1 ppmv), HCl (???70 ppbv), HF (???60 ppbv), and particles (which may have included fine silicate ash). We compare observed and modeled cloud compositions to understand its chemical evolution. Abundances of sulfur and halogen species indicate some oxidation of sulfur gases but limited scavenging and removal of halides. Chemical modeling suggests that cloud concentrations of water vapor and nitric acid promoted polar stratospheric cloud (PSC) formation at 201-203 K, yielding ice, nitric acid trihydrate (NAT), sulfuric acid tetrahydrate (SAT), and liquid ternary solution H2SO4/H2O/HNO3 (STS) particles. We show that these volcanically induced PSCs, especially the ice and NAT particles, activated volcanogenic halogens in the cloud producing >2 ppbv ClOx. This would have destroyed ozone during an earlier period of daylight, consistent with the very low levels of ozone observed. This combination of volcanogenic PSCs and chlorine destroyed ozone at much faster rates than other PSCs that Arctic winter. Elevated levels of HNO3 and NOy in the cloud can be explained by atmospheric nitrogen fixation in the eruption column due to high temperatures and/or volcanic lightning. However, observed elevated levels of HOx remain unexplained given that the cloud was sampled at night. Copyright 2006 by the American Geophysical Union.

  4. Folic acid - test

    MedlinePlus

    ... folic acid measurements include: Alcohol Aminosalicylic acid Birth control pills Estrogens Tetracyclines Ampicillin Chloramphenicol Erythromycin Methotrexate Penicillin Aminopterin Phenobarbital Phenytoin Drugs to treat malaria

  5. Oxalic acid poisoning

    MedlinePlus

    Symptoms of oxalic acid poisoning include: Abdominal pain Burns and blisters where the acid contacted the skin Collapse Convulsions Mouth pain Shock Throat pain Tremors (unintentional trembling) Vomiting

  6. Acid distribution in phosphoric acid fuel cells

    SciTech Connect

    Okae, I.; Seya, A.; Umemoto, M.

    1996-12-31

    Electrolyte acid distribution among each component of a cell is determined by capillary force when the cell is not in operation, but the distribution under the current load conditions had not been clear so far. Since the loss of electrolyte acid during operation is inevitable, it is necessary to store enough amount of acid in every cell. But it must be under the level of which the acid disturbs the diffusion of reactive gases. Accordingly to know the actual acid distribution during operation in a cell is very important. In this report, we carried out experiments to clarify the distribution using small single cells.

  7. 21 CFR 520.90b - Ampicillin trihydrate tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., tonsillitis, and bronchitis due to Streptococcus spp., Staphylococcus spp., Escherichia coli, Proteus mirabilis, and Pasteurella spp., urinary tract infections (cystitis) due to Streptococcus spp., Staphylococcus spp., E., coli, P. mirabilis, and Enterococcus spp.; gastrointestinal infections due...

  8. 21 CFR 522.88 - Sterile amoxicillin trihydrate for suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... organisms as follows: Respiratory infections (tonsillitis, tracheobronchitis) due to Staphylococcus aureus... caused by susceptible strains of organisms as follows: Upper respiratory infections due to S. aureus... within 5 days, review the diagnosis and change therapy. As with all antibiotics, appropriate in...

  9. 21 CFR 522.88 - Sterile amoxicillin trihydrate for suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... organisms as follows: Respiratory infections (tonsillitis, tracheobronchitis) due to Staphylococcus aureus... caused by susceptible strains of organisms as follows: Upper respiratory infections due to S. aureus... within 5 days, review the diagnosis and change therapy. As with all antibiotics, appropriate in...

  10. 21 CFR 522.88 - Sterile amoxicillin trihydrate for suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... organisms as follows: Respiratory infections (tonsillitis, tracheobronchitis) due to Staphylococcus aureus... caused by susceptible strains of organisms as follows: Upper respiratory infections due to S. aureus... within 5 days, review the diagnosis and change therapy. As with all antibiotics, appropriate in...

  11. 21 CFR 522.88 - Sterile amoxicillin trihydrate for suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... organisms as follows: Respiratory infections (tonsillitis, tracheobronchitis) due to Staphylococcus aureus... caused by susceptible strains of organisms as follows: Upper respiratory infections due to S. aureus... within 5 days, review the diagnosis and change therapy. As with all antibiotics, appropriate in...

  12. 21 CFR 520.90e - Ampicillin trihydrate soluble powder.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...) Indications for use. Oral treatment of porcine colibacillosis (Escherichia coli) and salmonellosis (Salmonella... Pasteurella multocida, Staphylococcus spp., Streptococcus spp., and Salmonella spp. (3) Limitations. For...

  13. 21 CFR 520.90e - Ampicillin trihydrate soluble powder.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Indications for use. Oral treatment of porcine colibacillosis (Escherichia coli) and salmonellosis (Salmonella... Pasteurella multocida, Staphylococcus spp., Streptococcus spp., and Salmonella spp. (3) Limitations. For...

  14. 21 CFR 522.90b - Ampicillin trihydrate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., bacterial pneumonia (shipping fever, calf pneumonia, and bovine pneumonia) caused by Aerobacter spp., Klebsiella spp., Staphylococcus spp., Streptococcus spp., Pasteurella multocida, and Escherichia coli....

  15. 21 CFR 520.90f - Ampicillin trihydrate boluses.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... daily for up to 5 days. (i) Indications for use. Oral treatment of colibacillosis caused by Escherichia coli, bacterial enteritis caused by Salmonella spp., and bacterial pneumonia caused by Pasteurella spp... enteritis (colibacillosis) caused by E. coli. (ii) Limitations. Treated calves must not be slaughtered...

  16. 21 CFR 520.90f - Ampicillin trihydrate boluses.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... daily for up to 5 days. (i) Indications for use. Oral treatment of colibacillosis caused by Escherichia coli, bacterial enteritis caused by Salmonella spp., and bacterial pneumonia caused by Pasteurella spp... enteritis (colibacillosis) caused by E. coli. (ii) Limitations. Treated calves must not be slaughtered...

  17. 21 CFR 522.90a - Ampicillin trihydrate sterile suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... daily, for up to 3 days. (B) Indications for use. Treatment of bacterial enteritis caused by Escherichia coli and bacterial pneumonia caused by Pasteurella spp. susceptible to ampicillin. (C) Limitations. Not... tract infections due to E. coli, Pseudomonas spp., Proteus spp., Staphylococcus spp., and...

  18. 21 CFR 522.90a - Ampicillin trihydrate sterile suspension.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... daily, for up to 3 days. (B) Indications for use. Treatment of bacterial enteritis caused by Escherichia coli and bacterial pneumonia caused by Pasteurella spp. susceptible to ampicillin. (C) Limitations. Not... tract infections due to E. coli, Pseudomonas spp., Proteus spp., Staphylococcus spp., and...

  19. 21 CFR 520.88f - Amoxicillin trihydrate tablets.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... day. (ii) Indications for use. Treatment of bacterial dermatitis due to Staphylococcus aureus, Streptococcus spp., Staphylococcus spp., and Escherichia coli; and soft tissue infections (abscesses, wounds, lacerations) due to S. aureus, Streptococcus spp., E. coli, Proteus mirabilis, and Staphylococcus spp....

  20. 21 CFR 522.90b - Ampicillin trihydrate for suspension.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    .... Treatment of respiratory tract infections caused by organisms susceptible to ampicillin, bacterial pneumonia (shipping fever, calf pneumonia, and bovine pneumonia) caused by Aerobacter spp., Klebsiella...

  1. 21 CFR 520.90c - Ampicillin trihydrate capsules.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... penicillinase-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for...-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for use...

  2. 21 CFR 520.90c - Ampicillin trihydrate capsules.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... penicillinase-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for...-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for use...

  3. 21 CFR 520.90c - Ampicillin trihydrate capsules.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... penicillinase-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for...-producing organisms and for use in animals known to be allergic to any of the penicillins. Not for use...

  4. 21 CFR 520.90c - Ampicillin trihydrate capsules.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Limitations. The drug may be given as an emergency measure; however, in vitro sensitivity tests on samples... be given as an emergency measure; however, in vitro sensitivity tests on samples collected prior...

  5. 21 CFR 520.90c - Ampicillin trihydrate capsules.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...) Limitations. The drug may be given as an emergency measure; however, in vitro sensitivity tests on samples... be given as an emergency measure; however, in vitro sensitivity tests on samples collected prior...

  6. 21 CFR 520.90b - Ampicillin trihydrate tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., tonsillitis, and bronchitis due to Streptococcus spp., Staphylococcus spp., Escherichia coli, Proteus...., Staphylococcus spp., E., coli, P. mirabilis, and Enterococcus spp.; gastrointestinal infections due to Staphylococcus spp., Streptococcus spp., Enterococcus spp., and E. coli. ; infections associated with...

  7. 21 CFR 522.90a - Ampicillin trihydrate sterile suspension.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... daily, for up to 3 days. (B) Indications for use. Treatment of bacterial enteritis caused by Escherichia coli and bacterial pneumonia caused by Pasteurella spp. susceptible to ampicillin. (C) Limitations. Not... tract infections due to E. coli, Pseudomonas spp., Proteus spp., Staphylococcus spp., and...

  8. 21 CFR 520.90f - Ampicillin trihydrate boluses.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... daily for up to 5 days. (i) Indications for use. Oral treatment of colibacillosis caused by Escherichia coli, bacterial enteritis caused by Salmonella spp., and bacterial pneumonia caused by Pasteurella spp... enteritis (colibacillosis) caused by E. coli. (ii) Limitations. Treated calves must not be slaughtered...

  9. 21 CFR 520.90b - Ampicillin trihydrate tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., tonsillitis, and bronchitis due to Streptococcus spp., Staphylococcus spp., Escherichia coli, Proteus...., Staphylococcus spp., E., coli, P. mirabilis, and Enterococcus spp.; gastrointestinal infections due to Staphylococcus spp., Streptococcus spp., Enterococcus spp., and E. coli. ; infections associated with...

  10. 21 CFR 520.88f - Amoxicillin trihydrate tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., Streptococcus spp., Staphylococcus spp., and Escherichia coli; and soft tissue infections (abscesses, wounds, lacerations) due to S. aureus, Streptococcus spp., E. coli, Proteus mirabilis, and Staphylococcus spp....

  11. 21 CFR 520.88f - Amoxicillin trihydrate tablets.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ..., Streptococcus spp., Staphylococcus spp., and Escherichia coli; and soft tissue infections (abscesses, wounds, lacerations) due to S. aureus, Streptococcus spp., E. coli, Proteus mirabilis, and Staphylococcus spp....

  12. 21 CFR 520.90b - Ampicillin trihydrate tablets.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ..., tonsillitis, and bronchitis due to Streptococcus spp., Staphylococcus spp., Escherichia coli, Proteus...., Staphylococcus spp., E., coli, P. mirabilis, and Enterococcus spp.; gastrointestinal infections due to Staphylococcus spp., Streptococcus spp., Enterococcus spp., and E. coli. ; infections associated with...

  13. 21 CFR 520.88f - Amoxicillin trihydrate tablets.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ..., Streptococcus spp., Staphylococcus spp., and Escherichia coli; and soft tissue infections (abscesses, wounds, lacerations) due to S. aureus, Streptococcus spp., E. coli, Proteus mirabilis, and Staphylococcus spp....

  14. 21 CFR 520.90f - Ampicillin trihydrate boluses.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... daily for up to 5 days. (i) Indications for use. Oral treatment of colibacillosis caused by Escherichia coli, bacterial enteritis caused by Salmonella spp., and bacterial pneumonia caused by Pasteurella spp... enteritis (colibacillosis) caused by E. coli. (ii) Limitations. Treated calves must not be slaughtered...

  15. 21 CFR 520.90f - Ampicillin trihydrate boluses.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... daily for up to 5 days. (i) Indications for use. Oral treatment of colibacillosis caused by Escherichia coli, bacterial enteritis caused by Salmonella spp., and bacterial pneumonia caused by Pasteurella spp... enteritis (colibacillosis) caused by E. coli. (ii) Limitations. Treated calves must not be slaughtered...

  16. 21 CFR 522.90a - Ampicillin trihydrate sterile suspension.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... daily, for up to 3 days. (B) Indications for use. Treatment of bacterial enteritis caused by Escherichia coli and bacterial pneumonia caused by Pasteurella spp. susceptible to ampicillin. (C) Limitations. Not... tract infections due to E. coli, Pseudomonas spp., Proteus spp., Staphylococcus spp., and...

  17. 21 CFR 522.90a - Ampicillin trihydrate suspension.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...) Indications for use. For treatment of bacterial enteritis in calves caused by Escherichia coli and bacterial... for use. Treatment of bacterial enteritis (colibacillosis) caused by E. coli and bacterial pneumonia...—(A) Treatment of respiratory tract infections due to E. coli, Pseudomonas spp., Proteus...

  18. 21 CFR 526.88 - Amoxicillin trihydrate for intramammary infusion.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ...—Lactating cows—(1) Amount. One syringe (equivalent to 62.5 milligrams amoxicillin) per quarter. (2) Indications for use. For the treatment of subclinical infectious bovine mastitis due to Streptococcus agalactiae and Straphylococcus aureus (penicillin sensitive). (3) Limitations. Administer after...

  19. 21 CFR 526.88 - Amoxicillin trihydrate for intramammary infusion.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Streptococcus agalactiae and Straphylococcus aureus (penicillin sensitive). (3) Limitations. Administer after... of use—Lactating cows—(1) Amount. One syringe (equivalent to 62.5 milligrams amoxicillin) per...

  20. 21 CFR 526.88 - Amoxicillin trihydrate for intramammary infusion.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Streptococcus agalactiae and Straphylococcus aureus (penicillin sensitive). (3) Limitations. Administer after... of use—Lactating cows—(1) Amount. One syringe (equivalent to 62.5 milligrams amoxicillin) per...

  1. 21 CFR 526.88 - Amoxicillin trihydrate for intramammary infusion.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Streptococcus agalactiae and Straphylococcus aureus (penicillin sensitive). (3) Limitations. Administer after... of use—Lactating cows—(1) Amount. One syringe (equivalent to 62.5 milligrams amoxicillin) per...

  2. 21 CFR 526.88 - Amoxicillin trihydrate for intramammary infusion.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... Streptococcus agalactiae and Straphylococcus aureus (penicillin sensitive). (3) Limitations. Administer after... of use—Lactating cows—(1) Amount. One syringe (equivalent to 62.5 milligrams amoxicillin) per...

  3. Gastroprotective mechanisms of action of semisynthetic carnosic acid derivatives in human cells.

    PubMed

    Theoduloz, Cristina; Pertino, Mariano Walter; Schmeda-Hirschmann, Guillermo

    2013-01-01

    Carnosic acid (CA) and its semisynthetic derivatives display relevant gastroprotective effects on HCl/ethanol induced gastric lesions in mice. However, little is known on the mechanisms of action of the new compounds. The aim of the present work was to assess the gastroprotective action mechanisms of CA and its derivatives using human cell culture models. A human gastric adenocarcinoma cell line (AGS) and lung fibroblasts (MRC-5) were used to reveal the possible mechanisms involved. The ability of the compounds to protect cells against sodium taurocholate (NaT)-induced damage, and to increase the cellular reduced glutathione (GSH) and prostaglandin E2 (PGE2) content was determined using AGS cells. Stimulation of cell proliferation was studied employing MRC-5 fibroblasts. Carnosic acid and its derivatives 10-18 raised GSH levels in AGS cells. While CA did not increase the PGE2 content in AGS cells, all derivatives significantly stimulated PGE2 synthesis, the best effect being found for the 12-O-indolebutyrylmethylcarnosate 13. A significant increase in MRC-5 fibroblast proliferation was observed for the derivatives 7 and 16-18. The antioxidant effect of the compounds was assessed by the inhibition of lipid peroxidation in human erythrocyte membranes, scavenging of superoxide anion and DPPH discoloration assay. The new CA derivatives showed gastroprotective effects by different mechanisms, including protection against cell damage induced by NaT, increase in GSH content, stimulation of PGE2 synthesis and cell proliferation. PMID:24399049

  4. Development of flame and smoke retardant thermoplastic molding compounds

    NASA Technical Reports Server (NTRS)

    Mueller, W. A.; Ingham, J. D.; Reilly, W. W.

    1980-01-01

    Compositions of polypropylene and ethylene-acrylic acid resins filled with high levels of alumina trihydrate of magnesium hydroxide were examined for smoke generation and impact resistance. Best results were obtained using alumina trihydrate coated with a low modulus elastomer, and ethylene-acrylic acid resin. Addition of polyvinyl alcohol fibers to the filled resin improves impact resistance and causes somewhat of an increase in smoke evolution.

  5. Evaluation of gastric toxicity of indomethacin acid, salt form and complexed forms with hydroxypropyl-beta-cyclodextrin on Wistar rats: histopathologic analysis.

    PubMed

    Ribeiro-Rama, A C; Figueiredo, Isabel Vitoria; Veiga, F; Castel-Branco, M M; Cabrita, A M S; Caramona, M M

    2009-12-01

    Indomethacin (IM) is a non-steroidal anti-inflammatory drug which inhibits prostaglandin biosynthesis. It is practically insoluble in water and has the capacity to induce gastric injury. Hydroxypropyl-beta-cyclodextrin (HP-beta-CD) is an alkylated derivative of beta-CD with the capacity to form inclusion complexes with suitable molecules. IM is considered to form partial inclusion complexes with HP-beta-CD by enclosure of the p-chlorobenzoic part of the molecule in the cyclodextrin channel, reducing the adverse effects. The aim of this paper is to evaluate the gastric damage induced by the IM inclusion complex prepared by freeze-drying and spray-drying. A total of 135 Wistar rats weighing 224.4 +/- 62.5 g were put into 10 groups. They were allowed free access to water but were maintained fasted for 18 h before the first administration until the end of the experiment. IM acid-form, IM trihydrated-sodium-salt and IM-HP-beta-CD spray and freeze-dried, at normal and toxic doses, were administered through gastric cannula once/day for 3 days. Seventy-two hours after the first administration, the animals were sacrificed and the stomachs collected and prepared for morphological study by using the haematoxylin-eosin technique. Lesion indexes (rated 0/4) were developed and the type of injury was scored according to the severity of damage and the incidence of microscopic evidence of harm. Microscopic assessment demonstrated levels of injury with index one on 10-25%. The type of complexation method had different incidence but the same degree. The results show that IM inclusion complexation protects against gastric injury, reducing the incidence and the maximum degree of severity from 4 to 1, with a better performance of the spray-dried complex. PMID:19656206

  6. Polar stratospheric clouds climatology over Dumont d'Urville between 1989 and 1993 and the influence of volcanic aerosols on their formation

    NASA Astrophysics Data System (ADS)

    David, C.; Bekki, S.; Godin, S.; MéGie, G.; Chipperfield, M. P.

    1998-09-01

    The first polar stratospheric clouds (PSCs) climatology ever established from lidar data and relative to a specific site is presented here. It is based on lidar backscatter and depolarization measurements of PSCs carried out between 1989 and 1993 at Dumont d'Urville (66°S, 140°E), which is a primary station of the Network for Detection of Stratospheric Changes (NDSC). The climatology was subdivided based on the stratospheric sulphuric acid aerosol content (background aerosols in 1989-1991 and volcanic aerosols in 1992-1993 following the Mount Pinatubo eruption). PSCs were mainly observed in July and August. Very few water ice clouds (type II) were detected. Most of the PSCs tended to form around the peak in sulphuric acid aerosol, between 17 and 23 km in 1989-1991 and between 11 and 20 km in 1992-1993. This tendency suggests that sulphuric acid aerosols are very likely to act as condensation nuclei for PSCs. As shown by previous lidar studies [Browell et al, 1990], two type I subclasses were identified: depolarizing (nonspherical) particles (type Ia) and nondepolarizing (spherical) particles (type Ib). No type Ia PSCs were detected above the nitric acid trihydrate (NAT) saturation temperature, TNAT, lending support to the theory that NAT is the main component of type Ia PSCs. There was also no evidence of the existence of sulphuric acid tetrahydrate (SAT) in the data. Some type Ib PSCs were observed close to the frost point, showing that supersaturation with respect to NAT is a necessary, but not sufficient, condition for the existence of solid PSCs. No type Ib PSCs were clearly detected above TNAT in 1989-1991 whereas 18% of the PSCs seem to be found at temperatures above TNAT in 1992-1993. This difference might be linked to the HNO3 uptake by volcanic sulphuric acid particles starting at higher temperatures. The fraction of type Ia out of the total PSCs observations was lower in 1992-1993 than in 1989-1991. This difference was not found to be highly

  7. Acid tolerance in amphibians

    SciTech Connect

    Pierce, B.A.

    1985-04-01

    Studies of amphibian acid tolerance provide information about the potential effects of acid deposition on amphibian communities. Amphibians as a group appear to be relatively acid tolerant, with many species suffering increased mortality only below pH 4. However, amphibians exhibit much intraspecific variation in acid tolerance, and some species are sensitive to even low levels of acidity. Furthermore, nonlethal effects, including depression of growth rates and increases in developmental abnormalities, can occur at higher pH.

  8. Toxicity of adipic acid.

    PubMed

    Kennedy, Gerald L

    2002-05-01

    Adipic acid has very low acute toxicity in rats with an LD50 > 5000 mg/kg. Adipic acid produced mild to no skin irritation on intact guinea pig skin as a 50% concentration in propylene glycol; it was not a skin sensitizer. Adipic acid caused mild conjunctival irritation in washed rabbit eyes; in unwashed rabbit eyes, there was mild conjunctival irritation, minimal iritis, but no corneal effects. Adipic acid dust may irritate the mucous membranes of the lungs and nose. In a 2-year feeding study, rats fed adipic acid at concentrations up to 5% in the diet exhibited only weight loss. Adipic acid is not genetically active in a wide variety of assay systems. Adipic acid caused no developmental toxicity in mice, rats, rabbits, or hamsters when administered orally. Adipic acid is partially metabolized in humans; the balance is eliminated unchanged in the urine. Adipic acid is slightly to moderately toxic to fish, daphnia, and algae in acute tests. PMID:12024802

  9. Acid Thunder: Acid Rain and Ancient Mesoamerica

    ERIC Educational Resources Information Center

    Kahl, Jonathan D. W.; Berg, Craig A.

    2006-01-01

    Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…

  10. Quantity of acid in acid fog

    SciTech Connect

    Deal, W.J.

    1983-07-01

    This communication notes the actual magnitude of the acidity in acidic fog particles and suggests a possible line of inquiry into the health effects of such fog so that it can be determined whether a typical fog is detrimental or beneficial relative to dry air.

  11. [Amino acids in saliva].

    PubMed

    Klinger, G; Gruhn, K

    1984-01-01

    Total amino acids in saliva and free and peptide-bound amino acids from 21 saliva samples were determined. The contents of amino acids was 25 mmol/1; total nitrogen content was 78-80 mmol/1. Amino acids consist of Prolin in 25%. Some patients were examined before and after application of the depot estrogen ethinyl estradiosulfonat, which stimulates the assimilation of protein. After application, amino acids increased and the authors found a shift between the single amino acids. Estrogen medication induced an increase in proteins with the character of collagens. Clinical effects are discussed. (author's modified) PMID:6240853

  12. Hydrochloric acid poisoning

    MedlinePlus

    Hydrochloric acid is a clear, poisonous liquid. It is highly corrosive, which means it immediately causes severe damage, ... discusses poisoning due to swallowing or breathing in hydrochloric acid. This article is for information only. Do NOT ...

  13. Omega-3 Fatty Acids

    MedlinePlus

    Omega-3 fatty acids are used together with lifestyle changes (diet, weight-loss, exercise) to reduce the amount ... the blood in people with very high triglycerides. Omega-3 fatty acids are in a class of medications ...

  14. Omega-6 Fatty Acids

    MedlinePlus

    Omega-6 fatty acids are types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean oils. Other types of omega-6 fatty acids are found in black currant seed, borage seed, ...

  15. Zoledronic Acid Injection

    MedlinePlus

    Zoledronic acid (Reclast) is used to prevent or treat osteoporosis (condition in which the bones become thin and weak ... of life,' end of regular menstrual periods). Zoledronic acid (Reclast) is also used to treat osteoporosis in ...

  16. Aminolevulinic Acid Topical

    MedlinePlus

    Aminolevulinic acid is used in combination with photodynamic therapy (PDT; special blue light) to treat actinic keratoses (small crusty ... skin cancer) of the face or scalp. Aminolevulinic acid is in a class of medications called photosensitizing ...

  17. Acid-fast stain

    MedlinePlus

    The acid-fast stain is a laboratory test that determines if a sample of tissue, blood, or other body ... dye. The slide is then washed with an acid solution and a different stain is applied. Bacteria ...

  18. Uric acid - blood

    MedlinePlus

    Uric acid is a chemical created when the body breaks down substances called purines. Purines are found in some ... dried beans and peas, and beer. Most uric acid dissolves in blood and travels to the kidneys. ...

  19. Hydrochloric acid poisoning

    MedlinePlus

    Hydrochloric acid is a clear, poisonous liquid. It is highly corrosive, which means it immediately causes severe damage, such ... poisoning due to swallowing or breathing in hydrochloric acid. This article is for information only. Do NOT ...

  20. Omega-6 Fatty Acids

    MedlinePlus

    ... types of fats. Some types are found in vegetable oils, including corn, evening primrose seed, safflower, and soybean ... from studying specific omega-6 fatty acids or plant oils containing omega-6 fatty acids. See the separate ...