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Sample records for acid molar ratio

  1. Molar ratio iron: zinc and folic acid in Brazilian biscuits and snacks and test for classification using principal component analyses.

    PubMed

    Godoy, Adriana Teixeira; Rebelatto, Ana Paula; Borin-Nogueira, Alessandra; Lima-Pallone, Juliana Azevedo

    2014-06-01

    The aim of the present work was to evaluate molar ratio iron: zinc and the levels of folic acid in biscuit and snacks commercialized in Brazil, prepared with folic acid and iron fortified flours. These nutrients are important for human nutrition; however, iron can have a negative effect on zinc absorption. Molar ratio iron:zinc can indicate if there will be any problems for absorption of these nutrients. The folic acid content varied from 58 to 433 μg/100 g and iron and zinc levels varied from 2.9 to 9.4 mg/100 g and from 0.2 to 1.3 mg/100 g, respectively, for 75 analyzed samples. The average iron contents observed in the products and molar ratio iron:zinc (in average 8:1 for biscuits and 12.8:1 for snacks) could result in problems with the zinc absorption. Moreover, principal compo- nent analyses (PCA) indicated low uniformity in the distribution of minerals and vitamin in the majority of the samples, mainly among brands. The results indicated that for the majority of the samples tested folic acid and iron content was higher than expected for flours and could be useful to governmental authorities in their evaluation program of flour fortification. PMID:25799687

  2. Evaluating controlling factors to Al(i)/(Ca + Mg) molar ratio in acidic soil water, southern and southwestern China: multivariate approach.

    PubMed

    Guo, Jing-Heng; Zhang, Xiao-Shan; Vogt, Rolf D; Xiao, Jin-Song; Zhao, Da-Wei; Xiang, Ren-Jun; Luo, Jia-Hai

    2007-06-01

    Al(i)/(Ca + Mg) molar ratio in soil water has been used as an indicator to the effects of acid deposition on terrestrial ecosystems. However, the main factors controlling this ratio have not been well documented in southern and southwestern China. In this study, we presented the variation in inorganic aluminum (Al(i)) and Al(i)/(Ca + Mg) molar ratio in different sites and soil horizons based on two to three years monitoring data, and evaluated the main factors controlling Al(i)/(Ca + Mg) molar ratio using principle component analysis (PCA) and partial least square (PLS) regression. Monitoring data showed although Al(i)/(Ca + Mg) molar ratios in most soil water were lower than assumed critical 1.0, higher molar ratios were found in some soil water at TSP and LXH site. Besides acid loading, both soil properties and soil water chemistry affected the value of Al(i)/(Ca + Mg) molar ratio in soil water. Partial least square (PLS) indicated that they had different relative importance in different soil horizons. In A-horizon, soil aluminum saturation (AlS) had higher influence on Al(i)/(Ca + Mg) molar ratio than soil water chemistry did; higher soil aluminum saturation (AlS) led to higher Al(i)/(Ca + Mg) molar ratio in soil water. In the deeper horizons (i.e., B(1)-, B(2)- and BC-horizon), inorganic aluminum (Al(i)) in soil water had more and more important role in regulating Al(i)/(Ca + Mg) molar ratio. On regional scale, soil aluminum saturation (AlS) as well as cation exchange capacity (CEC) was the dominant factor controlling Al(i)/(Ca + Mg) molar ratio. This should be paid enough attention on when making regional acid rain control policy in China. PMID:17057971

  3. Biodegradable in situ gelling delivery systems containing pilocarpine as new antiglaucoma formulations: effect of a mercaptoacetic acid/N-isopropylacrylamide molar ratio.

    PubMed

    Lai, Jui-Yang

    2013-01-01

    Ocular drug delivery is one of the most commonly used treatment modalities in the management of glaucoma. We have recently proposed the use of gelatin and poly(N-isopropylacrylamide) (PNIPAAm) graft copolymers as biodegradable in situ forming delivery systems for the intracameral administration of antiglaucoma medications. In this study, we further investigated the influence of carrier characteristics on drug delivery performance. The carboxyl-terminated PNIPAAm samples with different molecular weights were synthesized by varying the molar ratio of mercaptoacetic acid (MAA)/N-isopropylacrylamide (NIPAAm) from 0.05 to 1.25, and were determined by end-group titration. The preparation of gelatin-g-PNIPAAm (GN) copolymers from these thermoresponsive polymers was achieved using carbodiimide chemistry. Our results showed that the carboxylic end-capped PNIPAAm of high molecular weight may lead to the lower thermal phase transition temperature and slower degradation rate of GN vehicles than its low molecular weight counterparts. With a decreasing MAA/NIPAAm molar ratio, the drug encapsulation efficiency of copolymers was increased due to fast temperature-triggered capture of pilocarpine nitrate. The degradation of the gelatin network could greatly affect the drug release profiles. All of the GN copolymeric carriers demonstrated good corneal endothelial cell and tissue compatibility. It is concluded that different types of GN-based delivery systems exhibit noticeably distinct intraocular pressure-lowering effect and miosis action, thereby reflecting the potential value of a MAA/NIPAAm molar ratio in the development of new antiglaucoma formulations. PMID:24187486

  4. Biodegradable in situ gelling delivery systems containing pilocarpine as new antiglaucoma formulations: effect of a mercaptoacetic acid/N-isopropylacrylamide molar ratio

    PubMed Central

    Lai, Jui-Yang

    2013-01-01

    Ocular drug delivery is one of the most commonly used treatment modalities in the management of glaucoma. We have recently proposed the use of gelatin and poly(N-isopropylacrylamide) (PNIPAAm) graft copolymers as biodegradable in situ forming delivery systems for the intracameral administration of antiglaucoma medications. In this study, we further investigated the influence of carrier characteristics on drug delivery performance. The carboxyl-terminated PNIPAAm samples with different molecular weights were synthesized by varying the molar ratio of mercaptoacetic acid (MAA)/N-isopropylacrylamide (NIPAAm) from 0.05 to 1.25, and were determined by end-group titration. The preparation of gelatin-g-PNIPAAm (GN) copolymers from these thermoresponsive polymers was achieved using carbodiimide chemistry. Our results showed that the carboxylic end-capped PNIPAAm of high molecular weight may lead to the lower thermal phase transition temperature and slower degradation rate of GN vehicles than its low molecular weight counterparts. With a decreasing MAA/NIPAAm molar ratio, the drug encapsulation efficiency of copolymers was increased due to fast temperature-triggered capture of pilocarpine nitrate. The degradation of the gelatin network could greatly affect the drug release profiles. All of the GN copolymeric carriers demonstrated good corneal endothelial cell and tissue compatibility. It is concluded that different types of GN-based delivery systems exhibit noticeably distinct intraocular pressure-lowering effect and miosis action, thereby reflecting the potential value of a MAA/NIPAAm molar ratio in the development of new antiglaucoma formulations. PMID:24187486

  5. Influence of the Metal Nitrates to Citric Acid Molar Ratio on the Processing of Nickel Zinc Ferrite Nanocrystalline Powders Synthesized by a Sol-Gel Auto Combustion Method

    NASA Astrophysics Data System (ADS)

    Barati, M. R.; Ebrahimi, S. A. Seyyed; Badiei, A.

    2009-06-01

    Nanocrystalline powder of the single phase nickel-zinc ferrite have been prepared by a sol-gel auto-combustion process. The nitrate-citrate gels were prepared from metal nitrates and citric acid solutions with various molar ratios of the metal nitrates to citric acid. The results showed that the nitrate citrate gels exhibit a self-propagating behavior after ignition in air. The thermal decomposition of nitrate-citrate gels and the phase evolution of the as-burnt powder were investigated by differential thermal analysis and thermogravimetry (DTA/TG) and X-ray diffraction (XRD) techniques respectively. Transmission electron microscope (TEM) was used to characterize the microstructure of the material. Magnetic properties were also measured by a vibrating sample magnetometer (VSM) with a maximum applied field of 10 kOe. The results also revealed that the molar ratio of the metal nitrates to citric acid has important effects on the formation temperature and the crystallite size which affect the magnetic properties of the nickel-zinc ferrite.

  6. Determining Molar Combining Ratios Using Radioisotopes--A Student Experiment

    ERIC Educational Resources Information Center

    Sears, Jerry A.

    1976-01-01

    Outlines an experimental procedure in which an iodine radioisotope is used to determine molar combining ratios of lead and silver with the iodine. Tables and graphs show the definitive results that should be attainable. (CP)

  7. Molar extinction coefficients of some fatty acids

    NASA Astrophysics Data System (ADS)

    Sandhu, G. K.; Singh, Kulwant; Lark, B. S.; Gerward, L.

    2002-10-01

    The attenuation of gamma rays in some fatty acids, viz. formic acid (CH 2O 2), acetic acid (C 2H 4O 2), propionic acid (C 3H 6O 2), butyric acid (C 4H 8O 2), n-hexanoic acid (C 6H 12O 2), n-caprylic acid (C 8H 16O 2), lauric acid (C 12H 24O 2), myristic acid (C 14H 28O 2), palmitic acid (C 16H 32O 2), oleic acid (C 18H 34O 2) and stearic acid (C 18H 36O 2), has been measured at the photon energies 81, 356, 511, 662, 1173 and 1332 keV. Experimental values for the molar extinction coefficient, the effective atomic number and the electron density have been derived and compared with theoretical calculations. There is good agreement between experiment and theory.

  8. Formation of polyelectrolyte complexes with diethylaminoethyl dextran: charge ratio and molar mass effect.

    PubMed

    Le Cerf, Didier; Pepin, Anne Sophie; Niang, Pape Momar; Cristea, Mariana; Karakasyan-Dia, Carole; Picton, Luc

    2014-11-26

    The formation of polyelectrolyte complexes (PECs) between carboxymethyl pullulan and DEAE Dextran, was investigated, in dilute solution, with emphasis on the effect of charge density (molar ratio or pH) and molar masses. Electrophoretic mobility measurements have evidenced that insoluble PECs (neutral electrophoretic mobility) occurs for charge ratio between 0.6 (excess of polycation) and 1 (stoichiometry usual value) according to the pH. This atypical result is explained by the inaccessibility of some permanent cationic charge when screened by pH dependant cationic ones (due to the Hoffman alkylation). Isothermal titration calorimetry (ITC) indicates an endothermic formation of PEC with a binding constant around 10(5) L mol(-1). Finally asymmetrical flow field flow fractionation coupled on line with static multi angle light scattering (AF4/MALS) evidences soluble PECs with very large average molar masses and size around 100 nm, in agreement with scrambled eggs multi-association between various polyelectrolyte chains. PMID:25256478

  9. High-Temperature CO2 Sorption on Hydrotalcite Having a High Mg/Al Molar Ratio.

    PubMed

    Kim, Suji; Jeon, Sang Goo; Lee, Ki Bong

    2016-03-01

    Hydrotalcites having a Mg/Al molar ratio between 3 and 30 have been synthesized as promising high-temperature CO2 sorbents. The existence of NaNO3 in the hydrotalcite structure, which originates from excess magnesium nitrate in the precursor, markedly increases CO2 sorption uptake by hydrotalcite up to the record high value of 9.27 mol kg(-1) at 240 °C and 1 atm CO2. PMID:26927529

  10. Lipogenesis in Huh7 cells is promoted by increasing the fructose: Glucose molar ratio

    PubMed Central

    Windemuller, Fernando; Xu, Jiliu; Rabinowitz, Simon S; Hussain, M Mahmood; Schwarz, Steven M

    2016-01-01

    AIM: To determine whether hepatocyte lipogenesis, in an in vitro cell culture model, is modulated by adjusting culture media monosaccharide content and concentration. METHODS: Hepatocytes (Huh7), demonstrating glucose and fructose uptake and lipid biosynthesis, were incubated in culture media containing either glucose alone (0.65-0.72 mmol/L) or isosmolar monosaccharide (0.72 mmol/L) comprising fructose:glucose (F:G) molar ratios ranging from 0.58-0.67. Following a 24-h incubation, cells were harvested and analyzed for total protein, triglyceride (TG) and cholesterol (C) content. Significant differences (P < 0.05) among groups were determined using analysis of variance followed by Dunnett’s test for multiple comparisons. RESULTS: After a 24 h incubation period, Huh7 cell mass and viability among all experimental groups were not different. Hepatocytes cultured with increasing concentrations of glucose alone did not demonstrate a significant change either in C or in TG content. However, when the culture media contained increasing F:G molar ratios, at a constant total monosaccharide concentration, synthesis both of C and of TG increased significantly [F:G ratio = 0.58, C/protein (μg/μg) = 0.13; F:G = 0.67, C/protein = 0.18, P < 0.01; F:G ratio = 0.58, TG/protein (μg/μg) = 0.06; F:G ratio = 0.67, TG/protein = 0.11, P < 0.01]. CONCLUSION: In an in vitro hepatocyte model, glucose or fructose plus glucose support total cell mass and lipogenic activity. Increasing the fructose:glucose molar ratio (but not glucose alone) enhances triglyceride and cholesterol synthesis. These investigations demonstrate fructose promotes hepatocellular lipogenesis, and they provide evidence supporting future, in vivo studies of fructose’s role in the development of hepatic steatosis and non-alcoholic fatty liver disease. PMID:27458503

  11. Co-production of acetone and ethanol with molar ratio control enables production of improved gasoline or jet fuel blends.

    PubMed

    Baer, Zachary C; Bormann, Sebastian; Sreekumar, Sanil; Grippo, Adam; Toste, F Dean; Blanch, Harvey W; Clark, Douglas S

    2016-10-01

    The fermentation of simple sugars to ethanol has been the most successful biofuel process to displace fossil fuel consumption worldwide thus far. However, the physical properties of ethanol and automotive components limit its application in most cases to 10-15 vol% blends with conventional gasoline. Fermentative co-production of ethanol and acetone coupled with a catalytic alkylation reaction could enable the production of gasoline blendstocks enriched in higher-chain oxygenates. Here we demonstrate a synthetic pathway for the production of acetone through the mevalonate precursor hydroxymethylglutaryl-CoA. Expression of this pathway in various strains of Escherichia coli resulted in the co-production of acetone and ethanol. Metabolic engineering and control of the environmental conditions for microbial growth resulted in controllable acetone and ethanol production with ethanol:acetone molar ratios ranging from 0.7:1 to 10.0:1. Specifically, use of gluconic acid as a substrate increased production of acetone and balanced the redox state of the system, predictively reducing the molar ethanol:acetone ratio. Increases in ethanol production and the molar ethanol:acetone ratio were achieved by co-expression of the aldehyde/alcohol dehydrogenase (AdhE) from E. coli MG1655 and by co-expression of pyruvate decarboxylase (Pdc) and alcohol dehydrogenase (AdhB) from Z. mobilis. Controlling the fermentation aeration rate and pH in a bioreactor raised the acetone titer to 5.1 g L(-1) , similar to that obtained with wild-type Clostridium acetobutylicum. Optimizing the metabolic pathway, the selection of host strain, and the physiological conditions employed for host growth together improved acetone titers over 35-fold (0.14-5.1 g/L). Finally, chemical catalysis was used to upgrade the co-produced ethanol and acetone at both low and high molar ratios to higher-chain oxygenates for gasoline and jet fuel applications. Biotechnol. Bioeng. 2016;113: 2079-2087. © 2016 Wiley

  12. Lipid Concentration and Molar Ratio Boundaries for the Use of Isotropic Bicelles

    PubMed Central

    2014-01-01

    Bicelles are model membranes generally made of long-chain dimyristoylphosphatidylcholine (DMPC) and short-chain dihexanoyl-PC (DHPC). They are extensively used in the study of membrane interactions and structure determination of membrane-associated peptides, since their composition and morphology mimic the widespread PC-rich natural eukaryotic membranes. At low DMPC/DHPC (q) molar ratios, fast-tumbling bicelles are formed in which the DMPC bilayer is stabilized by DHPC molecules in the high-curvature rim region. Experimental constraints imposed by techniques such as circular dichroism, dynamic light scattering, or microscopy may require the use of bicelles at high dilutions. Studies have shown that such conditions induce the formation of small aggregates and alter the lipid-to-detergent ratio of the bicelle assemblies. The objectives of this work were to determine the exact composition of those DMPC/DHPC isotropic bicelles and study the lipid miscibility. This was done using 31P nuclear magnetic resonance (NMR) and exploring a wide range of lipid concentrations (2–400 mM) and q ratios (0.15–2). Our data demonstrate how dilution modifies the actual DMPC/DHPC molar ratio in the bicelles. Care must be taken for samples with a total lipid concentration ≤250 mM and especially at q ∼ 1.5–2, since moderate dilutions could lead to the formation of large and slow-tumbling lipid structures that could hinder the use of solution NMR methods, circular dichroism or dynamic light scattering studies. Our results, supported by infrared spectroscopy and molecular dynamics simulations, also show that phospholipids in bicelles are largely segregated only when q > 1. Boundaries are presented within which control of the bicelles’ q ratio is possible. This work, thus, intends to guide the choice of q ratio and total phospholipid concentration when using isotropic bicelles. PMID:24797658

  13. BrO/SO2 molar ratios from scanning DOAS measurements in the NOVAC network

    NASA Astrophysics Data System (ADS)

    Lübcke, P.; Bobrowski, N.; Arellano, S.; Galle, B.; Garzón, G.; Vogel, L.; Platt, U.

    2013-11-01

    The molar ratio of BrO to SO2 is, like other halogen/sulphur ratios, a~possible precursor for dynamic changes in the shallow part of a volcanic system. While the predictive significance of the BrO/SO2 ratio has not been well constrained yet, it has the major advantage that this ratio can be readily measured using the remote-sensing technique Differential Optical Absorption Spectroscopy (DOAS) in the UV. While BrO/SO2 ratios have been measured during several short-term field campaigns this article presents an algorithm that can be used to obtain long-term time series of BrO/SO2 ratios from the scanning DOAS instruments of the Network for Observation of Volcanic and Atmospheric Change (NOVAC) or comparable networks. Parameters of the DOAS retrieval of both trace gases are given and the influence of co-adding spectra on the retrieval error will be investigated. Difficulties in the evaluation of spectroscopic data from monitoring instruments in volcanic environments and possible solutions are discussed. The new algorithm is demonstrated by evaluating data from the NOVAC scanning DOAS systems at Nevado del Ruiz, Colombia encompassing almost four years of measurements between November 2009 and end of June 2013. This dataset shows variations of the BrO/SO2 ratio several weeks prior to the eruption on 30 June 2012.

  14. BrO/SO2 molar ratios from scanning DOAS measurements in the NOVAC network

    NASA Astrophysics Data System (ADS)

    Lübcke, P.; Bobrowski, N.; Arellano, S.; Galle, B.; Garzón, G.; Vogel, L.; Platt, U.

    2014-06-01

    The molar ratio of BrO to SO2 is, like other halogen/sulfur ratios, a possible precursor for dynamic changes in the shallow part of a volcanic system. While the predictive significance of the BrO/SO2 ratio has not been well constrained yet, it has the major advantage that this ratio can be readily measured using the remote-sensing technique differential optical absorption spectroscopy (DOAS) in the UV. While BrO/SO2 ratios have been measured during several short-term field campaigns, this article presents an algorithm that can be used to obtain long-term time series of BrO/SO2 ratios from the scanning DOAS instruments of the Network for Observation of Volcanic and Atmospheric Change (NOVAC) or comparable networks. Parameters of the DOAS retrieval of both trace gases are given. The influence of co-adding spectra on the retrieval error and influences of radiative transfer will be investigated. Difficulties in the evaluation of spectroscopic data from monitoring instruments in volcanic environments and possible solutions are discussed. The new algorithm is demonstrated by evaluating data from the NOVAC scanning DOAS systems at Nevado del Ruiz, Colombia, encompassing almost 4 years of measurements between November 2009 and end of June 2013. This data set shows variations of the BrO/SO2 ratio several weeks prior to the eruption on 30 June 2012.

  15. The selective synthesis of water-soluble highly luminescent CdTe nanoparticles and nanorods: The influence of the precursor Cd/Te molar ratio

    NASA Astrophysics Data System (ADS)

    Deng, Da-Wei; Qin, Yuan-Bin; Yang, Xi; Yu, Jun-Sheng; Pan, Yi

    2006-11-01

    In this report, we initially systematically investigated the influence of the precursor Cd/Te molar ratio on the morphology of water-soluble thiol-stabilized CdTe nanocrystals. By only changing the precursor Cd/Te molar ratio, highly luminescent CdTe nanoparticles (NPs) and nanorods (NRs) can be prepared selectively in the presence of the same concentration single ligand ( L-cysteine or thioglycolic acid) system. A high precursor Cd/Te molar ratio leads to isotropic spherical growth, whereas a low Cd/Te molar ratio promotes the linear self-assembly of NPs into NRs. Thus, a new efficient strategy has been developed in aqueous phase to prepare selectively highly luminescent dot- or rod-shaped CdTe nanocrystals in single ligand system. Then, we further explored the influence of the properties of initial CdTe dispersions with different luminescence maxima on the formation of NRs. The experiment results revealed that the formation of CdTe NRs is also dependent on the properties of initial CdTe dispersions. CdTe NPs with short wavelength emission (˜520-550 nm) can self-assemble directly into high quality CdTe NRs after storage at room temperature.

  16. Selenium:mercury molar ratios in freshwater fish from Tennessee: individual, species, and geographical variations have implications for management.

    PubMed

    Burger, Joanna; Gochfeld, Michael; Jeitner, C; Donio, M; Pittfield, T

    2012-06-01

    Vertebrates, including humans, can experience adverse effects from mercury consumed in fish. Humans often prefer large predatory fish that bioaccumulate high mercury levels. Recent attention has focused on the role of selenium countering mercury toxicity, but there is little research on the selenium:mercury molar ratios in freshwater fish. We examine selenium:mercury molar ratios in freshwater fish from Tennessee at Poplar Creek which receives ongoing inputs of mercury from the Department of Energy's Oak Ridge Y-12 facility. Our objective was to determine variation of the ratios within species that might affect the protectiveness of selenium against mercury toxicity. Within species, the ratio was correlated significantly and positively with fish length only for two species. There was great individual variation in the selenium:mercury molar ratio within each species, except striped bass. The lack of a clear relationship between the selenium:mercury molar ratio and fish length, and the intraspecific variation, suggests that it would be difficult to use the molar ratio in predicting either the risk from mercury toxicity or in devising consumption advisories. PMID:22456727

  17. Selenium:Mercury Molar Ratios in Freshwater Fish from Tennessee: Individual, Species, and Geographical Variations have Implications for Management

    PubMed Central

    Burger, Joanna; Gochfeld, Michael; Jeitner, C.; Donio, M.; Pittfield, T.

    2014-01-01

    Vertebrates, including humans, can experience adverse effects from mercury consumed in fish. Humans often prefer large predatory fish that bioaccumulate high mercury levels. Recent attention has focused on the role of selenium countering mercury toxicity, but there is little research on the selenium:mercury molar ratios in freshwater fish. We examine selenium:mercury molar ratios in freshwater fish from Tennessee at Poplar Creek which receives ongoing inputs of mercury from the Department of Energy’s Oak Ridge Y-12 facility. Our objective was to determine variation of the ratios within species that might affect the protectiveness of selenium against mercury toxicity. Within species, the ratio was correlated significantly and positively with fish length only for two species. There was great individual variation in the selenium:mercury molar ratio within each species, except striped bass. The lack of a clear relationship between the selenium:mercury molar ratio and fish length, and the intraspecific variation, suggests that it would be difficult to use the molar ratio in predicting either the risk from mercury toxicity or in devising consumption advisories. PMID:22456727

  18. Variations of the BrO/SO2 molar ratios during the 2015 Cotopaxi eruption

    NASA Astrophysics Data System (ADS)

    Dinger, Florian; Arellano, Santiago; Battaglia, Jean; Bobrowski, Nicole; Galle, Bo; Hernandez, Stephen; Hidalgo, Silvana; Hörmann, Christoph; Lübcke, Peter; Platt, Ulrich; Ruiz, Mario; Warnach, Simon; Wagner, Thomas

    2016-04-01

    Cotopaxi volcano is located 50 km south of Quito, the capital of Ecuador. In case of a large eruption producing lahars, these may cause damage to the inhabited areas located to the south and north of the volcano and to the local water supply and other infrastructure. After almost 140 years of relative quiescence, increasing activity is observed in seismicity and gas emissions since May 2015. During August 2015 ash and gas emissions are recorded. Cotopaxi volcano is part of the Network for Observation of Volcanic and Atmospheric Change (NOVAC) since 2009, thus the observations include the overall eruptive activity onset and its evolution. NOVAC regularly monitors the SO2 emissions of more than 30 volcanoes using scanning UV-spectrometers. Today, monitoring of volcanic SO2 emissions by UV-spectrometers is a widespread tool but its interpretation can be improved by additionally recording halogen/sulphur emission ratios. Recently, it has been shown that spectra from NOVAC instruments can also be used to retrieve the BrO/SO2 molar ratio by applying Differential Optical Absorption Spectroscopy (DOAS). We apply this new technique to analyse the plume composition of Cotopaxi volcano and will present time series of the BrO/SO2 ratios as monitored by the ground-based NOVAC instruments since March 2015. The SO2 column densities were below 6\\cdot1016 molec/cm^2 prior to May 2015 and up to 1.5\\cdot1018 molec/cm^2 between May and August 2015. For these periods, the BrO column densities were below the detection limit of 3\\cdot1013 molec/cm^2. After the phreatic explosions on 14.08.2015, SO2 column densities of up to 3\\cdot1018 molec/cm^2 and BrO column densities of up to 5\\cdot1014 molec/cm^2 were observed. Until December 2015 these SO2 column densities kept at about the same level but the BrO column densities increased up to 3\\cdot1014 molec/cm^2. After the phreatic explosions we find a detectable signal of BrO. Soon after the eruption the BrO/SO2 molar ratio was low as 1

  19. Approach for determination of ATP:ADP molar ratio in mixed solution by surface-enhanced Raman scattering.

    PubMed

    Fang, Hui; Yin, Hong Jun; Lv, Ming Yang; Xu, Hai Jun; Zhao, Yong Mei; Zhang, Xin; Wu, Zheng Long; Liu, Luo; Tan, Tian Wei

    2015-07-15

    The ATP:ADP molar ratio is an important physiological factor. However, in previous literatures, ATP and ADP could not be distinguished by Raman spectroscopy due to the high similarity of molecular structure. To challenge this problem, also considering that the γ phosphate group may interact with adenine group and cause a different variation of the Raman spectrum than that of ADP, a highly sensitive, low-cost, environment protecting, flexible and super-hydrophobic Au nanoparticles/cicada wing (Au/CW) substrate with three-dimension structure was fabricated and employed as an active surface-enhanced Raman scattering (SERS) substrate to detect the ATP:ADP molar ratios. The concentration as low as 10(-8)M for ATP and ADP was analyzed to determine the limit of detection. This SERS study on various ATP:ADP molar ratios demonstrates that ATP:ADP could be distinguished and the quantitative determination of ATP content was achieved. Moreover, a principle was speculated based on the molecular structures of ATP and ADP of the Raman peaks centered at ~685 and ~731cm(-1) to explain the linear relationship between the area ratio and the molar ratio. A new method has been developed for quantitative determination of ATP:ADP molar ratio based on Au/CW substrate by the SERS method. PMID:25703730

  20. Appearance of dentin gamma-carboxyglutamic acid-containing proteins in developing rat molars in vitro

    SciTech Connect

    Finkelman, R.D.; Butler, W.T.

    1985-07-01

    An in vitro model of mineralization was devised in order to study the developmental appearance of dentin gamma-carboxyglutamic acid-containing proteins (DGPs) in relation to the onset of mineralization. Maxillary third molars from 11-day-old rats were cultured with or without fetal calf serum (FCS) as modified from Navia et al. Molars were incubated without radiolabel, or with either /sup 45/CaCl/sub 2/ (5 microCi/ml) for 24 hr at various stages of a ten-day culture period or (/sup 3/H)-leucine (10 microCi/ml) for 24 hr at the eighth day of culture. Molars were lyophilized and extracted with 10% formic acid overnight at 4 degrees C. DGPs in extracts were detected by immunologic and chromatographic techniques; DGPs in molar sections were detected by immunolocalization using indirect immunofluorescence. Molar development was evaluated histologically using the Von Kossa staining technique. Molars cultured with FCS showed histologic evidence for mineralized dentin and enamel and a significant increase in /sup 45/Ca uptake after the sixth day in vitro. Eleven-day-old molars in vivo and molars cultured without FCS showed no evidence of the presence of mineralized tissues. (/sup 3/H)-Leucine-labeled DGPs were isolated and identified by affinity and reversed-phase high-performance liquid chromatography and by gel electrophoresis from both mineralized and unmineralized molars. DGP antigens were localized immunohistochemically using rabbit anti-rat antibodies raised against a highly purified DGP preparation. In the unmineralized molar, antigenicity was seen in odontoblasts but not in predentin matrix, preodontoblasts, or in any other cell type. Antigens in the mineralized molar were localized to odontoblasts and dentin.

  1. Effective molarity in a nucleic acid-controlled reaction.

    PubMed

    Catalano, Michael J; Price, Nathan E; Gates, Kent S

    2016-06-01

    Positioning of reactive functional groups within a DNA duplex can enable chemical reactions that otherwise would not occur to an appreciable extent. However, few studies have quantitatively defined the extent to which the enforced proximity of reaction partners in duplex DNA can favor chemical processes. Here, we measured substantial effective molarities (as high as 25M) afforded by duplex DNA to a reaction involving interstrand cross-link formation between 2'-deoxyadenosine and a 2-deoxyribose abasic (Ap) site. PMID:27117430

  2. Defluoridation of drinking water by combined electrocoagulation: effects of the molar ratio of alkalinity and fluoride to Al(III).

    PubMed

    Zhao, Hua-Zhang; Yang, Wei; Zhu, Jun; Ni, Jin-Ren

    2009-03-01

    The defluoridation efficiency (epsilon(F)) of electrocoagulation (EC) is closely related to the pH level of the F(-)-containing solution. The pH level usually needs to be adjusted by adding acid in order to obtain the highest epsilon(F) for the F(-)-containing groundwater. The use of combined EC (CEC), which is the combination of chemical coagulation with EC, was proposed to remove fluoride from drinking water for the first time in this study. The optimal scheme for the design and operation of CEC were obtained through experiments on the treatment of F(-)-containing groundwater. It was found, with OH(-) being the only alkalinity of the raw water, that the highest efficiency would be obtained when the molar ratio of alkalinity and fluoride to Al(III) (gamma(Alkalinity+F)) was controlled at 3.0. However, when the raw water contained HCO(3)(-) alkalinity, a correction coefficient was needed to correct the concentration of HCO(3)(-) to obtain the optimal defluoridation condition of gamma(Alkalinity+F)=3.0 for CEC. The correction coefficient of HCO(3)(-) concentration was concluded as 0.60 from the experiment. For the practical F(-)-containing groundwater treatment, CEC can achieve similar epsilon(F) as an acid-adding EC process. The consumption of aluminum electrode was decreased in CEC. The energy consumption also declined greatly in CEC, which is less than one third of that in the acid-adding EC process. PMID:19128818

  3. Influence of Ni/Co molar ratio on electromagnetic properties and microwave absorption performances for Ni/Co paraffin composites

    NASA Astrophysics Data System (ADS)

    Yan, S. J.; Dai, S. L.; Ding, H. Y.; Wang, Z. Y.; Liu, D. B.

    2014-05-01

    Ni and Co metallic microparticles with submicron size were synthesized with a simple wet chemical reduction method at a relatively low temperature. Then their morphologies and structures were characterized by SEM and XRD. Ni metallic microparticles have spherical-shape morphology with fcc crystalline structure, however, Co has a distinct leaf-like morphology with the fcc and hcp mixed phases crystalline structures. For the characterization of their electromagnetic properties, paraffin matrix composites containing different molar ratio Ni and Co mixture powder as fillers were prepared. It was found that both the electromagnetic properties and electromagnetic microwave absorption performances of absorber layer were remarkably influenced by Ni/Co molar ratio. The electromagnetic microwave absorption performances were significantly improved by blending Ni and Co metallic microparticles into paraffin matrix with changing Ni/Co molar ratio, and enhanced mechanism were discussed.

  4. Aripiprazole-Cyclodextrin Binary Systems for Dissolution Enhancement: Effect of Preparation Technique, Cyclodextrin Type and Molar Ratio

    PubMed Central

    M. Badr-Eldin, Shaimaa; A. Ahmed, Tarek; R Ismail, Hatem

    2013-01-01

    Objective(s): The aim of this work was to investigate the effect of the natural and the chemically modified form of cyclodextrins namely; β-cyclodextrin (β-CD) and hydroxypropyl-β-cyclodextrin (HP-β-CD) respectively on the solubility and dissolution rate of aripiprazole; an antipsychotic medication showing poor aqueous solubility. Materials and Methods: Phase solubility of aripiprazole with the studied CDs and the complexation efficiency values (CE) which reflect the solubilizing power of the CDs towards the drug was performed. Solid binary systems of aripiprazole with CDs were prepared by kneading, microwave irradiation and freeze-drying techniques at 1:1 and 1:2 (drug to CD) molar ratios. Drug-CD physical mixtures were also prepared in the same molar ratios for comparison. The dissolution of aripiprazole-binary systems was carried out to select the most appropriate CD type, molar ratio and preparation technique. Results: Phase solubility study indicated formation of higher order complexes and the complexation efficiency values was higher for HP-β-CD compared to β-CD. Drug dissolution study revealed that aripiprazole dissolution was increased upon increasing the CD molar ratio and, the freeze-drying technique was superior to the other studied methods especially when combined with the HP-β-CD. The cyclodextrin type, preparation technique and molar ratio exhibited statistically significant effect on the drug dissolution at P≤ 0.05. Conclusion: The freeze-dried system prepared at molar ratio 1:2 (drug: CD) can be considered as efficient tool for enhancing aripiprazole dissolution with the possibility of improving its bioavailability. PMID:24570827

  5. Pulp/tooth ratio of mandibular first and second molars on panoramic radiographs: An aid for forensic age estimation

    PubMed Central

    Shah, Palak H.; Venkatesh, Rashmi

    2016-01-01

    Objective: To determine and compare the accuracy of pulp/tooth ratio method in mandibular first and second molar teeth in forensic age estimation. Materials and Methods: A total 300 panoramic radiographs of the Gujarati population (187 males and 113 females) were studied. The measurements of Pulp Chamber Height (PCH) and Crown Root Trunk Height (CRTH) were performed on the mandibular first and second molar teeth. The acquired data was subjected to correlation and regression. Results: The pulp chamber crown root trunk height ratios (PCTHR) of both the first (r = −0.609) and second molars (r = −0.422) were significantly correlated with the age of the individual. Individual regression formulae were derived for both the teeth which were then used separately to calculate the age. The standard errors estimate (SEE) for the first and second molars were 8.84 years and 10.11 years, respectively. There was no statistically significant difference between chronological and calculated age by both the teeth (P = 1.000). Conclusion: The mandibular first and second molar is a potential tool for age estimation in forensic dentistry. The pulp/tooth ratio of both the teeth is a useful method for forensic age prediction with reasonable accuracy in the Gujarati population.

  6. Influence of magnesia-to-phosphate molar ratio on microstructures, mechanical properties and thermal conductivity of magnesium potassium phosphate cement paste with large water-to-solid ratio

    SciTech Connect

    Xu, Biwan; Ma, Hongyan; Li, Zongjin

    2015-02-15

    This paper describes the influence of the magnesia-to-phosphate (M/P) molar ratios ranging from 4 to 12, on the properties and microstructures of magnesium potassium phosphate cement (MKPC) pastes with a large water-to-solid ratio (w/s) of 0.50. The setting behavior, compressive strength, tensile bonding strength and thermal conductivity of the MKPC pastes, were investigated. The results show that an increase in the M/P ratio can slow down the setting reaction, and clearly degrade the mechanical strengths, but clearly improve the thermal conductivity of MKPC pastes. Furthermore, micro-characterizations including X-ray diffraction, scanning electron microscopy and thermogravimetric analysis, on the MKPC pastes reveal that a lower M/P ratio can facilitate better crystallization of the resultant magnesium potassium phosphate hexahydrate (MKP) and a denser microstructure. Moreover, strong linear correlations are found between the mechanical strengths and the MKP-to-space ratio, and between thermal conductivity and the volume ratio of the unreacted magnesia to the MKP. - Highlights: • Increase of M/P molar ratio causes clear mechanical degradations on MKPC pastes. • Thermal conductivity of MKPC pastes is improved with increase of M/P molar ratio. • Lower M/P ratio leads to better MKP crystallization and denser microstructure. • Strengths of MKPC pastes are linearly correlated to the MKP-to-space ratios. • Thermal conductivity is affected by the volume ratio of unreacted magnesia to MKP.

  7. Determination of Si/Al molar ratios in microporous zeolites using calibration-free laser induced breakdown spectroscopy

    NASA Astrophysics Data System (ADS)

    Horňáčková, M.; Horňáček, M.; Rakovský, J.; Hudec, P.; Veis, P.

    2013-10-01

    In this paper, the potential application of a calibration-free laser-induced breakdown spectroscopy (CF-LIBS) method for the determination of the silicon-to-aluminum molar ratio in microporous zeolites (with both intermediate and high silica contents) is discussed. Three different zeolite types, i.e., mordenite and zeolites type Y and ZSM-5, were analyzed in this study and were shown to have Si/Al molar ratios in the range between 2.3 and 51.8. Many ionic and neutral atomic spectral lines of silicon and aluminum were detected in the measured LIBS spectra in the spectral range 200-1000 nm, but not all of the observed spectral lines are convenient for a CF-LIBS analysis. To increase the accuracy of the results, only lines with no or low self-absorption probability were selected. A systematic method is proposed to select spectral lines based on three main parameters: the transition probability (Einstein coefficient), the lower level energy of the observed transition and the number density ratio between singly ionized and neutral species (as calculated for Si and Al for the measured electron density and electron temperature). The calculated Si/Al molar ratios were close to that determined by wet chemical analysis with an average relative standard deviation of approximately 5% (maximum less than 15%). Our results point to the possibility of using CF-LIBS for analysis of these types of materials and for determination of Si/Al molar ratios.

  8. Corneal Stromal Cell Growth on Gelatin/Chondroitin Sulfate Scaffolds Modified at Different NHS/EDC Molar Ratios

    PubMed Central

    Lai, Jui-Yang

    2013-01-01

    A nanoscale modification strategy that can incorporate chondroitin sulfate (CS) into the cross-linked porous gelatin materials has previously been proposed to give superior performance for designed corneal keratocyte scaffolds. The purpose of this work was to further investigate the influence of carbodiimide chemistry on the characteristics and biofunctionalities of gelatin/CS scaffolds treated with varying N-hydroxysuccinimide (NHS)/1-ethyl-3-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) molar ratios (0–1) at a constant EDC concentration of 10 mM. Results of Fourier transform infrared spectroscopy and dimethylmethylene blue assays consistently indicated that when the NHS to EDC molar ratio exceeds a critical level (i.e., 0.5), the efficiency of carbodiimide-mediated biomaterial modification is significantly reduced. With the optimum NHS/EDC molar ratio of 0.5, chemical treatment could achieve relatively high CS content in the gelatin scaffolds, thereby enhancing the water content, glucose permeation, and fibronectin adsorption. Live/Dead assays and interleukin-6 mRNA expression analyses demonstrated that all the test samples have good cytocompatibility without causing toxicity and inflammation. In the molar ratio range of NHS to EDC from 0 to 0.5, the cell adhesion ratio and proliferation activity on the chemically modified samples significantly increased, which is attributed to the increasing CS content. Additionally, the materials with highest CS content (0.143 ± 0.007 nmol/10 mg scaffold) showed the greatest stimulatory effect on the biosynthetic activity of cultivated keratocytes. These findings suggest that a positive correlation is noticed between the NHS to EDC molar ratio and the CS content in the biopolymer matrices, thereby greatly affecting the corneal stromal cell growth. PMID:23337203

  9. Zn-Al layered double hydroxide prepared at different molar ratios: Preparation, characterization, optical and dielectric properties

    SciTech Connect

    Ahmed, Abdullah Ahmed Ali; Talib, Zainal Abidin; Zobir bin Hussein, Mohd; Zakaria, Azmi

    2012-07-15

    The co-precipitation method was used to prepare Zn-Al-NO{sub 3}-LDH at different Zn{sup 2+}/Al{sup 3+} molar ratios (2, 3, 4, 5 and 6) and pH value of 7.5. The structure, textural, composition and morphological properties were investigated using powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR) and scanning electron microscope (SEM), respectively. The crystallinity of LDH samples were found to improve as molar ratio decreased which is attributed to the distortion of the hydroxide layers networks of the LDH crystal by the larger difference in ionic radii of Zn{sup 2+} and Al{sup 3+}. The optical band gap energy of LDH samples were evaluated using absorbance data from UV-Vis-NIR Diffuse reflectance spectroscopy. Band gaps were affected by the variation of the Zn{sup 2+}/Al{sup 3+} molar ratio is due to the formation of the low crystalline phases (ZnO and ZnAl{sub 2}O{sub 4}). The water molecules and anionic NO{sub 3}{sup -} in the LDH interlayer were responsible for the generation of the dielectric response. This response can be described by an anomalous low frequency dispersion using the second type of Universal Power Law. The dominance of ZnO dipoles and charge carriers (NO{sub 3}{sup -} ions) in the dielectric relaxation increases with the increasing molar ratio. - Graphical abstract: (a) Schematic diagram of Zn-Al- NO{sub 3}-LDH shows the LDH structure, (b) Kubelka-Munk transformed reflectance spectra and c. The dielectric constant versus frequency of Zn-Al- NO{sub 3}-LDH samples. Highlights: Black-Right-Pointing-Pointer Zn-Al-NO{sub 3}-LDH was prepared at different Zn{sup 2+}/Al{sup 3+} molar ratios (2, 3, 4, 5 and 6). Black-Right-Pointing-Pointer The crystallinity of LDH phase decreased with increase of Zn{sup 2+}/Al{sup 3+} molar ratio. Black-Right-Pointing-Pointer The optical band gaps of LDH samples have been measured. Black-Right-Pointing-Pointer Dielectric response of LDH can be described by anomalous low

  10. Determination of the Molar Volume of Hydrogen from the Metal-Acid Reaction: An Experimental Alternative.

    ERIC Educational Resources Information Center

    de Berg, Kevin; Chapman, Ken

    1996-01-01

    Describes an alternative technique for determining the molar volume of hydrogen from the metal-acid reaction in which the metal sample is encased in a specially prepared cage and a pipette filler is used to fill an inverted burette with water. Eliminates some difficulties encountered with the conventional technique. (JRH)

  11. Molar proportions of volatile fatty acids in the gastrointestinal tract of East African wild ruminants.

    PubMed

    Clemens, E T; Maloiy, G M; Sutton, J D

    1983-01-01

    The molar proportions of seven individual VFA's were determined at select sites along the gastrointestinal tract of sixteen species of East African wild ruminants. The resulting data were statistically analyzed for species effect, and for effects due to major feeding groups (browsers, grazers, fresh grass grazers, etc.) and for body weight groups (5-750 kg animals). Present data suggest that body weight, rather than diet, is the more influential factor in reticulo-rumen fermentation rate, and in the molar proportion of fatty acids present. The molar proportions of VFA's observed in the mid and hindgut of these wild ruminants appeared more responsive to diet and body weight of the animal than did foregut VFA values. PMID:6139202

  12. Can the Follicle-Crown Ratio of the Impacted Third Molars be a Reliable Indicator of Pathologic Problem?

    PubMed Central

    Haghanifar, Sina; Moudi, Ehsan; Seyedmajidi, Maryam; Mehdizadeh, Mohammad; Nosrati, Kamran; Abbaszadeh, Naghi; Bijani, Ali; Ghorbani, Hakimeh

    2014-01-01

    Statement of the Problem: The presence of impacted third molars in the jaws is a common finding in the routine dental examination of patients. Concerning the odontogenic components of the dental follicle, it can be the origin of different types of odontogenic cysts and tumors. Purpose: The aim of this study was to find feasible radiographic criteria to help differentiate between normal and pathological dental follicles. Materials and Method: 134 asymptomatic impacted third molars were recruited in this study. Then, based on the radiographic measurements, the ratio between the diameter of the dental follicle and the mesiodistal width of the tooth crown was calculated. After surgical removal of impacted third molars, the related dental follicles were evaluated histopathologically. Statistical analyses were performed by adopting chi-square test, t-test, receiver oprating characteristic (ROC) curve, and logistic regression using SPSS-19 software. Results: The mean ratio of the dental follicle’s diameter to the mesiodistal width, in the normal and cystic follicle group was 1.18 ± 0.07 and 1.18 ± 0.08, respectively. There was no statistically significant difference between this ratio and the histopathological evaluation. Based on the logistic regression analysis, only the age >20 years and inflammation had predictive value in identifying cystic changes in dental follicle. Conclusion: According to the findings of the current study, the ratio of dental follicle diameter to the mesiodistal width of the teeth cannot not be employed as a diagnostic index to differentiate between normal and pathological dental follicle. PMID:25469358

  13. Selenium and mercury molar ratios in commercial fish from New Jersey and Illinois: Variation within species and relevance to risk communication

    PubMed Central

    Burger, Joanna; Gochfeld, Michael

    2015-01-01

    There is an emerging consensus that people consuming large amounts of fish with selenium:mercury ratios below 1 may be at higher risk from mercury toxicity. As the relative amount of selenium increases compared to mercury, risk may be lowered, but it is unclear how much excess selenium is required. It would be useful if the selenium:mercury ratio was relatively consistent within a species, but this has not been the case in our studies of wild-caught fish. Since most people in developed countries and urban areas obtain their fish and other seafood commercially, we examined selenium:mercury molar ratios in commercial fish purchased in stores and fish markets in central New Jersey and Chicago. There was substantial interspecific and intraspecific variation in molar ratios. Across species the selenium:mercury molar ratio decreased with increasing mean mercury levels, but selenium variation also contributed to the ratio. Few samples had selenium:mercury molar ratios below 1, but there was a wide range in ratios, complicating the interpretation for use in risk management and communication. Before ratios can be used in risk management, more information is needed on mercury:selenium interactions and mutual bioavailability, and on the relationship between molar ratios and health outcomes. Further, people who are selenium deficient may be more at risk from mercury toxicity than others. PMID:23541437

  14. Variations in the methanesulfonate to sulfate molar ratio in submicrometer marine aerosol particles over the south Pacific Ocean

    NASA Technical Reports Server (NTRS)

    Bates, Timothy S.; Calhoun, Julie A.; Quinn, Patricia K.

    1992-01-01

    Seawater concentrations of dimethylsulfide (DMS) and atmospheric concentrations of DMS, sulfur dioxide, methanesulfonate (MSA), and non-sea-salt (nss) sulfate were measured over the eastern Pacific Ocean between 105 deg and 110 deg W from 20 deg N to 60 deg S during February and March 1989. Although the samples collected in the Southern Hemisphere appear to be of marine origin, no significant correlation was found between the latitudinal distributions of DMS, SO2, MSA, and nss SO4(2-). However, an inverse correlation was found between atmospheric temperature and the MSA to nss SO4(2-) molar ratio in submicrometer aerosol particles with a decrease in temperature corresponding to an increase in the molar ratio. Although this trend is consistent with laboratory results indicating the favored production of MSA at lower temperatures, it is contrary to Southern Hemisphere baseline station data. This suggests either a decrease in the supply of DMS relative to nonmarine sources of nss SO4(2-) at the baseline stations in winter or additional mechanisms that affect the relative production of MSA and nss SO4(2-).

  15. Selenium and mercury molar ratios in saltwater fish from New Jersey: Individual and species variability complicate use in human health fish consumption advisories☆

    PubMed Central

    Burger, Joanna; Gochfeld, Michael

    2014-01-01

    Balancing risk versus benefits to humans and other organisms from consuming fish is a national concern in the USA, as well as in many other parts of the world. Protecting public health is both a federal and state responsibility, and states respond by issuing fish consumption advisories, particularly for mercury. Recently it has been emphasized that the protective role of selenium against mercury toxicity depends on their molar ratios, which should be evaluated as an indication of selenium’s protective capacity, and incorporated in risk assessments for fish consumption. However, there is no single “protective” ratio agreed upon. In this paper we examine the selenium:mercury (Se:Hg) molar ratios in a wide range of saltwater fish caught and eaten by recreational fishers along the New Jersey coast. We were particularly interested in interspecific and intraspecific variability, and whether the molar ratios were consistent within a species, allowing for its use in managing risk. The selenium–mercury molar ratio showed significant variation among and within fish species. The molar ratio decreased with the size of the fish species, decreased with the mercury levels, and within a fish species, the selenium:mercury ratio decreased with fish size. As an essential element, selenium undergoes some homeostatic regulation, but it is also highly toxic. Within species, mercury level tends to increase with size, accounting for the negative relationship between size and ratio. This variability may make it difficult to use the selenium:mercury molar ratio in risk assessment, risk management, and risk communication at this time, and more information is needed on how mercury and selenium actually interact and on the relationship between the molar ratios and health outcomes. PMID:22405995

  16. Effects of acid treatment duration and sulfuric acid molarity on purification of multi-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Mortazavi, Seyedeh; Novinrooz, Abdul; Reyhani, Ali; Mirershadi, Soghra

    2010-12-01

    Multi-walled carbon nanotubes were synthesized using a Fe-Ni bimetallic catalyst supported by MgO using thermal chemical vapor deposition. Purification processes to remove unwanted carbon structures and other metallic impurities were carried out by boiling in sulfuric acid solution. Various analytical techniques such as TGA/DSC, Raman spectroscopy, SEM, HRTEM and EDAX were employed to investigate the morphology, graphitization and quality of the carbon nanotubes. The obtained results reveal the molarity of sulfuric acid and immersed time of the carbon nanotubes in the acid solution is very effective at purifying multi-walled carbon nanotubes. It was also found that 5 M concentration of boiling sulfuric acid for a 3 h treatment duration led to the highest removal of the impurities with the least destructive effect. Moreover, it was observed that acid treatment results in decreasing of CNTs' diameter.

  17. Effects of acid treatment duration and sulfuric acid molarity on purification of multi-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Mortazavi, Seyedeh Z.; Novinrooz, Abdul J.; Reyhani, Ali; Mirershadi, Soghra

    2010-12-01

    Multi-walled carbon nanotubes were synthesized using a Fe-Ni bimetallic catalyst supported by MgO using thermal chemical vapor deposition. Purification processes to remove unwanted carbon structures and other metallic impurities were carried out by boiling in sulfuric acid solution. Various analytical techniques such as TGA/DSC, Raman spectroscopy, SEM, HRTEM and EDAX were employed to investigate the morphology, graphitization and quality of the carbon nanotubes. The obtained results reveal the molarity of sulfuric acid and immersed time of the carbon nanotubes in the acid solution is very effective at purifying multi-walled carbon nanotubes. It was also found that 5 M concentration of boiling sulfuric acid for a 3 h treatment duration led to the highest removal of the impurities with the least destructive effect. Moreover, it was observed that acid treatment results in decreasing of CNTs’ diameter.

  18. Potential Moderating Effects of Selenium on Mercury Uptake and Selenium:Mercury Molar Ratios in Fish From Oak Ridge and Savannah River Site - 12086

    SciTech Connect

    Burger, Joanna; Gochfeld, Michael; Donio, Mark; Jeitner, Christian; Pittfield, Taryn

    2012-07-01

    Mercury contamination is an important remediation issue at the U.S. Department of Energy's (DOE) Oak Ridge Reservation and to a lesser extent at other DOE sites because of the hazard it presents, potential consequences to humans and eco-receptors, and completed pathways, to offsite receptors. Recent work has emphasized that selenium might ameliorate the toxicity of mercury, and we examine the selenium:mercury (Se:Hg) molar ratios in fish from Oak Ridge, and compare them to Se:Hg molar ratios in fish from the Savannah River. Selenium/mercury molar ratios varied considerably among and within fish species. There was considerable variation in the molar ratios for individual fish (as opposed to mean ratios by species) for freshwater fish from both sites. The inter-individual variation in molar ratios indicates that such that the molar ratios of mean Se and Hg concentrations may not be representative. Even for fish species with relatively low mercury levels, some individual fish have molar ratios less than unity, the value sometime thought to be protective. Selenium levels varied narrowly regardless of fish size, consistent with homeostatic regulation of this essential trace element. The data indicate that considerable attention will need to be directed toward variations and variances, as well as the mechanisms of the interaction of selenium and mercury, before risk assessment and risk management policies can use this information to manage mercury pollution and risk. Even so, if there are high levels of selenium in the fish from Poplar Creek on Oak Ridge, then the potential exists for some amelioration of adverse health effects, on the fish themselves, predators that eat them, and people who consume them. This work will aid DOE because it will allow managers and scientists to understand another aspect that affects fate and transport of mercury, as well as the potential effects of methylmercury in fish for human and ecological receptors. The variability within fish

  19. Effect of oxidizer to fuel molar ratio on particle size and DC conductivity of CeO2 nanoparticles

    NASA Astrophysics Data System (ADS)

    Harish, B. M.; Rajeeva, M. P.; Naveen, C. S.; Chaturmukha, V. S.; Avinash, B. S.; Jayanna, H. S.; Lamani, Ashok R.

    2016-05-01

    Cerium oxide nanoparticles were synthesized by solution combustion method with varying the oxidizer (cerium nitrate hexa hydrate) to fuel (Glycine) molar ratio. The prepared samples were characterized by UV-visible spectrometer, X-ray diffractometer (XRD), Scanning electron microscope (SEM) and Energy dispersive X-Ray analysis (EDAX). XRD pattern reveals the formation of cubic fluorite structure of CeO2. It was observed that finest crystallites were found at extreme fuel-deficient condition and it is good enough to produce favorable powder characteristics. The average crystallite size was found to be 14.46 nm to 21.57 nm. The temperature dependent dc conductivity was carried out using Keithley source meter between the temperature range from 300K to 573K. From this study it was found that the conductivity increases with increase of temperature due to semiconducting behavior of CeO2 and it decreases with particle size due to increase in the energy band gap.

  20. Interspecific and intraspecific variation in selenium:mercury molar ratios in saltwater fish from the Aleutians: Potential protection on mercury toxicity by selenium

    PubMed Central

    Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

    2014-01-01

    A number of factors affect the consumption risk from mercury in fish, including mercury levels, seasonal patterns of mercury concentrations, human consumption patterns, and sensitive populations (e.g. pregnant women, fetuses, young children, and yet unknown genetic factors). Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for saltwater fish. We examine levels of mercury and selenium in several species of fish and seabirds from the Aleutians (Alaska), determine selenium:mercury molar ratios, and examine species-specific and individual variation in the ratios as a means of exploring the use of the ratio in risk assessment and risk management. Variation among species was similar for mercury and selenium. There was significant inter-specific and intraspecific variation in selenium:mercury molar ratios for fish, and for birds. The mean selenium:mercury molar ratios for all fish and bird species were above 1, meaning there was an excess of selenium relative to mercury. It has been suggested that an excess of selenium confers some protective advantage for salt water fish, although the degree of excess necessary is unclear. The selenium:mercury molar ratio was significantly correlated negatively with total length for most fish species, but not for dolly varden. Some individuals of Pacific cod, yellow irish lord, rock greenling, Pacific halibut, dolly varden, and to a lesser extent, flathead sole, had selenium:mercury ratios below 1. No bird muscle had an excess of mercury (ratio below 1), and only glaucous-winged gull and pigeon guillemot had ratios between 1 and 5. There was a great deal of variation in selenium:mercury molar ratios within fish species, and within bird species, making it difficult and impractical to use these ratios in risk assessment or management, for fish advisories, or for consumers, particularly given the difficulty of interpreting the ratios. PMID:22664537

  1. Influence of B4C to TTIP Molar Ratio on Synthesis of Nano Titanium Diboride Powders via Sol-Gel Method

    NASA Astrophysics Data System (ADS)

    Sinaei Pour Fard, Hamed; Baharvandi, Hamidreza; Abdizadeh, Hossein

    Titanium diboride (TiB2) has attracted great interests for its excellent mechanical properties, chemical resistance and good thermal and electrical conductivities. So it is widely applied as cutting tool composites, wear resistant parts, metal melting crucibles and electrode materials. This paper presents synthesis of nano titanium diboride powders via sol-gel method using a mixture of TTIP and B4C as precursors. In the hydrolysis step, B4C to TTIP molar ratio varied from 1.3 to 2.5. Solution samples stirred well and after aging and drying process, they were heat treated in an argon atmosphere. X-ray diffraction (XRD) patterns and Scanning electron microscopy (SEM) analysis showed that the percentage of synthesized TiB2 increased gradually as the molar ratio of B4C to TTIP reached to 2.3, afterward increasing the B4C to TTIP molar ratio caused decreasing of titanium diboride percentage.

  2. Floc properties of polyaluminum ferric chloride in water treatment: The effect of Al/Fe molar ratio and basicity.

    PubMed

    Cao, Baichuan; Gao, Baoyu; Wang, Mengmeng; Sun, Xiaomei; Wang, Jin

    2015-11-15

    Producing flocs with desired properties is significant for contaminants removal in water treatment works. In this study, an inorganic composite coagulant, polyaluminum ferric chloride (PAFC), was prepared and used in surface water treatment, and the influence of Al/Fe molar ratio and basicity (B) on floc properties was investigated. The contribution of metal species analysis showed a competition relationship between Al and Fe in the pre-hydrolysis, while the monomeric contents decreased with the increase of B value. The investigation of floc properties was conducted on a laser scattering instrument, in terms of floc size, strength, recovery capacity and fractal dimension (Df). The largest floc size and the highest growth rate was achieved when Al/Fe=7:1 and B=1.5. Floc formed at the Al/Fe ratios of 5:1 and 7:1 were considered to be more compact. Meanwhile, the Df value increased when B value was increased. At Al/Fe=7:1 and B=1.5, strongest flocs were obtained. During the breakage period, the Df value increased. As lower shear was replaced, the floc size decreased continuously, with a further increase of Df value. However, after breakage at higher shear, all of the PAFC flocs showed capacity for regrowth and loose structures were formed. PMID:26232731

  3. Na/Cl molar ratio changes during a salting cycle and its application to the estimation of sodium retention in salted watersheds

    NASA Astrophysics Data System (ADS)

    Sun, Hongbing; Huffine, Maria; Husch, Jonathan; Sinpatanasakul, Leeann

    2012-08-01

    Using soil column experiments and data from natural watersheds, this paper analyzes the changes in Na/Cl molar ratios during a salting cycle of aqueous-soil systems. The soil column experiments involved introducing NaCl salt at various initial concentrations into multiple soil columns. At the start of a salting cycle in the column experiments, sodium was adsorbed more than chloride due to cation exchange processes. As a result, the initial Na/Cl molar ratio in column effluent was lower than 1, but increased thereafter. One-dimensional PHREEQC geochemical transport simulations also were conducted to further quantify these trends under more diverse scenarios. The experimentally determined Na/Cl molar ratio pattern was compared to observations in the annual salting cycle of four natural watersheds where NaCl is the dominant applied road deicing salt. Typically, Na/Cl molar ratios were low from mid-winter to early spring and increased after the bulk of the salt was flushed out of the watersheds during the summer, fall and early winter. The established relationship between the Na/Cl molar ratios and the amount of sodium retention derived from the column experiments and computer simulations present an alternative approach to the traditional budget analysis method for estimating sodium retention when the experimental and natural watershed patterns of Na/Cl molar ratio change are similar. Findings from this study enhance the understanding of sodium retention and help improve the scientific basis for future environmental policies intended to suppress the increase of sodium concentrations in salted watersheds.

  4. Na/Cl molar ratio changes during a salting cycle and its application to the estimation of sodium retention in salted watersheds.

    PubMed

    Sun, Hongbing; Huffine, Maria; Husch, Jonathan; Sinpatanasakul, Leeann

    2012-08-01

    Using soil column experiments and data from natural watersheds, this paper analyzes the changes in Na/Cl molar ratios during a salting cycle of aqueous-soil systems. The soil column experiments involved introducing NaCl salt at various initial concentrations into multiple soil columns. At the start of a salting cycle in the column experiments, sodium was adsorbed more than chloride due to cation exchange processes. As a result, the initial Na/Cl molar ratio in column effluent was lower than 1, but increased thereafter. One-dimensional PHREEQC geochemical transport simulations also were conducted to further quantify these trends under more diverse scenarios. The experimentally determined Na/Cl molar ratio pattern was compared to observations in the annual salting cycle of four natural watersheds where NaCl is the dominant applied road deicing salt. Typically, Na/Cl molar ratios were low from mid-winter to early spring and increased after the bulk of the salt was flushed out of the watersheds during the summer, fall and early winter. The established relationship between the Na/Cl molar ratios and the amount of sodium retention derived from the column experiments and computer simulations present an alternative approach to the traditional budget analysis method for estimating sodium retention when the experimental and natural watershed patterns of Na/Cl molar ratio change are similar. Findings from this study enhance the understanding of sodium retention and help improve the scientific basis for future environmental policies intended to suppress the increase of sodium concentrations in salted watersheds. PMID:22721859

  5. THERMAL AND SPECTROSCOPIC ANALYSES OF CAUSTIC LIDE SOLVENT EXTRACTION SOLVENT CONTACTED WITH 16 MOLAR AND 8 MOLAR NITRIC ACID

    SciTech Connect

    Fondeur, F; David Hobbs, D; Samuel Fink, S

    2007-07-12

    Thermal and spectroscopic analyses were performed on multiple layers formed from contacting Caustic Side Solvent Extraction (CSSX) solvent with 1 M or 3 M nitric acid. A slow chemical reaction occurs (i.e., over several weeks) between the solvent and 1 M or 3 M nitric acid as evidenced by color changes and the detection of nitro groups in the infrared spectrum of the aged samples. Thermal analysis revealed that decomposition of the resulting mixture does not meet the definition of explosive or deflagrating material.

  6. C:N:P Molar Ratios, Sources and 14C Dating of Surficial Sediments from the NW Slope of Cuba

    PubMed Central

    de la Lanza Espino, Guadalupe; Soto, Luis A.

    2015-01-01

    The surficial sediments recovered from 12 sites located near the channel axis of the Florida Straits and the lower slope off NW Cuba were analyzed for total organic carbon (TOC), nitrogen (TN), phosphorus (TP), elemental C:N:P ratios, C and N isotopic values, and 14C dating. The depth profiles of TOC, TN, and TP (0-18 cm) displayed a downcore trend and a significant variation. The TOC values were low (0.15 to 0.62%; 66 to 516 µmol g-1). Sites near the island’s lower slope had lower TOC average concentrations (158-333 µmol g-1) than those closer to the channel axis (averaging 341-516 µmol g-1; p <0.05). The TN concentrations near the lower slope attained 0.11% (80 µmol g-1), whereas, towards the channel axis, they decreased to 0.07% (55 µmol g-1; p<0.05). The C:N ratios ranged from 1.9 to 10.2. The mean molar C:N ratio (5.4) indicated a marine hemipelagic deposition. The TP was lower at sites near the lower slope (38.4 to 50.0 µmol g-1; 0.12% to 0.16%) than those near the channel axis (50.0 to 66 µmol g-1; 0.15 to 0.21%). C:P fluctuated from 7.7 to 14.1 in the surficial sediment layer. The bulk organic δ13Corg and δ15N values confirmed pelagic organic sources, and the 14C dating revealed that the sediments were deposited during the Holocene (1000-5000 yr BP). We suggest that the hydrodynamic conditions in the Straits influence vertical and advective fluxes of particulate organic material trapped in the mixed-layer, which reduces the particulate matter flux to the seabed. PMID:26110791

  7. Investigating the effect of mixing ratio on molar mass distributions of synthetic polymers determined by MALDI-TOF mass spectrometry using design of experiments.

    PubMed

    Brandt, Heike; Ehmann, Thomas; Otto, Matthias

    2010-11-01

    It is well known that the mixing ratio affects the molar mass distribution of synthetic polymers determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Surely, the molar mixing ratio determines whether a mass spectrum will be obtained or not. However, depending on the mass range, several effects such as multimer formation occur, which might be a source of errors in molar mass distribution calculations. In this study, the effect of mixing ratio was investigated for several synthetic polymers, including polystyrene (PS), poly(dimethylsiloxane) (PDMS), poly(ethylene glycol) (PEG), and poly(methyl methacrylate) (PMMA) using statistical designs of experiments. The 2(3) full factorial design was found to be suitable in the study of more than 1000 samples. The obtained MALDI mass spectra as well as the ANOVA statistics show that the mixing ratio affects the molar mass distribution. The optimal mixing ratio for a defined synthetic polymer depends on the studied combination (matrix, cationization reagent, solvent). PMID:20685132

  8. The effect of Cu/Zn molar ratio on CO2 hydrogenation over Cu/ZnO/ZrO2/Al2O3 catalyst

    NASA Astrophysics Data System (ADS)

    Shaharun, Salina; Shaharun, Maizatul S.; Mohamad, Dasmawati; Taha, Mohd F.

    2014-10-01

    Catalytic hydrogenation of carbon dioxide (CO2) to methanol is an attractive way to recycle and utilize CO2. A series of Cu / ZnO / Al2O3/ZrO2 catalysts (CZAZ) containing different molar ratios of Cu/Zn were prepared by the co-precipitation method and investigated in a stirred slurry autoclave system. The catalysts were characterized by temperature-programmed reduction (TPR), field emission scanning electron microscopy-energy dispersive analysis (FESEM-EDX), X-ray diffraction (XRD) and N2 adsorption-desorption. Higher surface area, SABET values (42.6-59.9 m2/g) are recorded at low (1) and high (5) Cu/Zn ratios with the minimum value of 35.71 m2/g found for a Cu/Zn of 3. The reducibility of the metal oxides formed after calcination of catalyst samples was also affected due to change in metal-support interaction. At a low reaction temperature of 443 K, total gas pressure of 3.0 MPa and 0.1 g/mL of the CZAZ catalyst, the selectivity to methanol decreased as the Cu/Zn molar ratio increased, and the maximum selectivity of 67.73 was achieved at Cu/Zn molar ratio of 1. With a reaction time of 3h, the best performing catalyst was CZAZ75 with Cu/Zn molar ratio of 5 giving methanol yield of 79.30%.

  9. Mercury and selenium levels, and selenium:mercury molar ratios of brain, muscle and other tissues in bluefish (Pomatomus saltatrix) from New Jersey, USA

    PubMed Central

    Burger, Joanna; Jeitner, Christian; Donio, Mark; Pittfield, Taryn; Gochfeld, Michael

    2015-01-01

    A number of contaminants affect fish health, including mercury and selenium, and the selenium: mercury molar ratio. Recently the protective effects of selenium on methylmercury toxicity have been publicized, particularly for consumption of saltwater fish. Yet the relative ameliorating effects of selenium on toxicity within fish have not been examined, nor has the molar ratio in different tissues, (i.e. brain). We examined mercury and selenium levels in brain, kidney, liver, red and white muscle, and skin and scales in bluefish (Pomatomus saltatrix) from New Jersey to determine whether there were toxic levels of either metal, and we computed the selenium: mercury molar ratios by tissues. Total mercury averaged 0.32 ± 0.02 ppm wet weight in edible muscle and 0.09 ± 0.01 ppm in brain. Selenium concentration averaged 0.37 ± 0.03 in muscle and 0.36 ± 0.03 ppm in brain. There were significant differences in levels of mercury, selenium, and selenium: mercury molar ratios, among tissues. Mercury and selenium levels were correlated in kidney and skin/scales. Mercury levels were highest in kidney, intermediate in muscle and liver, and lowest in brain and skin/scales; selenium levels were also highest in kidney, intermediate in liver, and were an order of magnitude lower in the white muscle and brain. Mercury levels in muscle, kidney and skin/scales were positively correlated with fish size (length). Selenium levels in muscle, kidney and liver were positively correlated with fish length, but in brain; selenium levels were negatively correlated with fish length. The selenium: mercury molar ratio was negatively correlated with fish length for white muscle, liver, kidney, and brain, particularly for fish over 50 cm in length, suggesting that older fish experience less protective advantages of selenium against mercury toxicity than smaller fish, and that consumers of bluefish similarly receive less advantage from eating larger fish. PMID:23202378

  10. Mercury and selenium in European catfish (Silurus glanis) from Northern Italian Rivers: can molar ratio be a predictive factor for mercury toxicity in a top predator?

    PubMed

    Squadrone, S; Benedetto, A; Brizio, P; Prearo, M; Abete, M C

    2015-01-01

    The study of mercury and selenium bioaccumulation in fish is crucially important for evaluating the extent of contamination in freshwater environments, and the possible health risk posed for humans when the antagonistic interactions of these two elements are considered. Several factors affect the risk of mercury intake from fish consumption, including mercury levels, human consumption patterns, and sensitive populations (e.g., pregnant women, foetuses, young children and unknown genetic factors). The protective effects of selenium on mercury toxicity have been extensively publicised in recent years, particularly targeting fish consumers. In this study, mercury (Hg) and selenium (Se) concentrations were determined in the muscle of European catfish (Silurus glanis) collected from North Italian Rivers. Differences in mercury and selenium levels, as a function of size, gender and location were investigated. Hg was strongly related to length, gender and location, while Se levels are not dependent on fish size or location. The mean Se/Hg molar ratio was strongly affected by location, and significantly related to length and age. Selenium was in molar excess of mercury in all sites, with a rank order of mean Se/Hg molar ratio of the Parma River (2.55)>Po River (1.71)>Tanaro River (1.66)>Bormida River (1.36). However, in 37% of analyzed samples, Hg exceeded the maximum level set by 1881/2006/EC and 629/2008/EC in fish muscle. The molar ratio of Se/Hg was <1 only in the presence of significantly high Hg levels (>0.5mg/kg), and therefore the mean molar ratio cannot be considered as a safety criterion in top predator fish. PMID:25460744

  11. Evaluation of the circadian profiles of serum dehydroepiandrosterone (DHEA), cortisol, and cortisol/DHEA molar ratio after a single oral administration of DHEA in elderly subjects.

    PubMed

    Ceresini, G; Morganti, S; Rebecchi, I; Freddi, M; Ceda, G P; Banchini, A; Solerte, S B; Ferrari, E; Ablondi, F; Valenti, G

    2000-04-01

    Aging is associated with a selective decline in circulating levels of dehydroepiandrosterone (DHEA) and its sulfate, with no major changes in cortisol secretion. In young subjects, serum levels of both DHEA and cortisol are regulated according to a circadian rhythm, and an age-related attenuation of DHEA, but not cortisol, circadian rhythmicity has been reported. Several trials have evaluated the effects of DHEA supplementation in elderly subjects, although the results are still controversial. However, no data are available on the 24-hour profile of DHEA circulating levels in elderly subjects with DHEA administration. In the present study, we evaluated the circadian rhythms of DHEA, cortisol, and the cortisol/DHEA molar ratio in old subjects treated with either placebo (old-PL) or a single 50-mg dose of DHEA (old-D), both administered orally at 0700 hours. For each variable, the circadian profiles were compared with those obtained in young control subjects. The group of young subjects displayed a circadian rhythm for both DHEA and cortisol serum concentrations but no rhythm for the cortisol/DHEA molar ratio. In the old-PL group, the circadian rhythm of DHEA was completely abolished, whereas significant rhythms for both cortisol and the cortisol/DHEA molar ratio were observed. Particularly, at each time point, the cortisol/DHEA molar ratio was significantly higher in these subjects versus the young group. In the old-D group, the circadian rhythm of DHEA was completely restored and was comparable to that observed in the young group. Analogous to the observations in young subjects, the profile of the cortisol/DHEA molar ratio in old-D subjects did not display any circadian rhythmicity, the values being almost completely comparable to those observed in young controls. Our data demonstrate that the circadian rhythm of DHEA is totally abolished in elderly subjects. A single 50-mg dose of DHEA administered orally at 0700 hours restores the circadian rhythmicity of serum

  12. Circulating fluidized bed gasification of low rank coal: Influence of O2/C molar ratio on gasification performance and sulphur transformation

    NASA Astrophysics Data System (ADS)

    Zhang, Haixia; Zhang, Yukui; Zhu, Zhiping; Lu, Qinggang

    2016-08-01

    To promote the utilization efficiency of coal resources, and to assist with the control of sulphur during gasification and/or downstream processes, it is essential to gain basic knowledge of sulphur transformation associated with gasification performance. In this research we investigated the influence of O2/C molar ratio both on gasification performance and sulphur transformation of a low rank coal, and the sulphur transformation mechanism was also discussed. Experiments were performed in a circulating fluidized bed gasifier with O2/C molar ratio ranging from 0.39 to 0.78 mol/mol. The results showed that increasing the O2/C molar ratio from 0.39 to 0.78 mol/mol can increase carbon conversion from 57.65% to 91.92%, and increase sulphur release ratio from 29.66% to 63.11%. The increase of O2/C molar ratio favors the formation of H2S, and also favors the retained sulphur transforming to more stable forms. Due to the reducing conditions of coal gasification, H2S is the main form of the released sulphur, which could be formed by decomposition of pyrite and by secondary reactions. Bottom char shows lower sulphur content than fly ash, and mainly exist as sulphates. X-ray photoelectron spectroscopy (XPS) measurements also show that the intensity of pyrite declines and the intensity of sulphates increases for fly ash and bottom char, and the change is more obvious for bottom char. During CFB gasification process, bigger char particles circulate in the system and have longer residence time for further reaction, which favors the release of sulphur species and can enhance the retained sulphur transforming to more stable forms.

  13. The color expression of copigmentation between malvidin-3-O-glucoside and three phenolic aldehydes in model solutions: The effects of pH and molar ratio.

    PubMed

    Zhang, Bo; He, Fei; Zhou, Pan-Pan; Liu, Yue; Duan, Chang-Qing

    2016-05-15

    Copigmentation was investigated in model solutions between the anthocyanin malvidin-3-O-glucoside and three phenolic aldehydes (vanillic, syringic and coniferyl aldehydes) as a function of the pH and the pigment/copigment molar ratio. Tristimulus colorimetry was applied to evaluate the chromatic variations induced by copigmentation process. The results indicated that the greatest magnitude of copigmentation was obtained at pH 3.0 and molar ratio of 1:100, being significantly higher with coniferyl aldehyde, followed by syringic and vanillic aldehydes. The equilibrium constant (K) and Gibbs free energies (ΔG°) determined here show a spontaneous exothermic reaction. Theoretical calculations (ΔGbinding, ΔE) specified the relative arrangement of the pigment and copigment molecules within the complexes. In addition, an atoms in molecules (AIM) analysis was used to explore the main driving forces contributing to the formation of copigmentation complexes. PMID:26775964

  14. Effect of reaction time and (Ca+Mg)/Al molar ratios on crystallinity of Ca-Mg-Al layered double Hydroxide

    NASA Astrophysics Data System (ADS)

    Heraldy, E.; Nugrahaningtyas, K. D.; Sanjaya, F. B.; Darojat, A. A.; Handayani, D. S.; Hidayat, Y.

    2016-02-01

    Ca-Mg-Al Layered Double Hydroxides (Ca-Mg-Al-LDH) compounds were successfully synthesized from brine water and AlCl3.6H2O as the starting materials by coprecipitation method. The product result was characterized by X-ray powder diffraction (XRD) and Fourier transform infrared (FT-IR). The effects of the reaction time and the molar ratios of the raw material on the crystallinity of Ca-Mg-Al-LDH were examining. Results show that increasing reaction time (30; 60 and 90 min.) could improve the crystallinity and monodispersity of layered double hydroxide compounds particles. The well-defined Ca-Mg- Al-LDH could be prepared with (Ca+Mg)/Al molar ratios 0.5.

  15. Does crown/implant ratio influence the survival and marginal bone level of short single implants in the mandibular molar? A preliminary investigation consisting of 12 patients.

    PubMed

    Ghariani, L; Segaan, L; Rayyan, M M; Galli, S; Jimbo, R; Ibrahim, A

    2016-02-01

    Crown/implant (C/I) ratio has been proven to not affect the survival of the implants; however, it is also a fact that no evidence exists with regard to the use of single short implants in the mandibular molar. The aim of this study was to determine whether the crown/implant ratios of single implant-supported fixed restorations on implants of 6-8 mm in the mandibular molar have an impact on the implant survival and marginal bone maintenance. Twelve short dental implants (6-8 mm) were installed and restored with single crowns, loaded after 3 months of healing. The restorations were divided according to crown-to-implant ratio into two groups: Group 1: C/I < 2.0 and Group 2: C/I ≧ 2.0. Alveolar bone loss was measured using CBCT scan, taken at the implant placement and after 12 months follow-up from loading. Reduced implant/crown ratio shown no statistic significant differences on implant survival and the alveolar bone level compared with recommended implant/crown ratio. Within the limitation of this study, it can be concluded that reduced C/I ratio could be used as a substitute for recommended C/I ratio in severely mandibular atrophic residual alveolar ridges. PMID:26333185

  16. A new method for the determination of the nitrogen content of nitrocellulose based on the molar ratio of nitrite-to-nitrate ions released after alkaline hydrolysis.

    PubMed

    Alinat, Elodie; Delaunay, Nathalie; Archer, Xavier; Mallet, Jean-Maurice; Gareil, Pierre

    2015-04-01

    A new method was proposed to determine the nitrogen content of nitrocelluloses (NCs). It is based on the finding of a linear relationship between the nitrogen content and the molar ratio of nitrite-to-nitrate ions released after alkaline hydrolysis. Capillary electrophoresis was used to monitor the concentration of nitrite and nitrate ions. The influences of hydrolysis time and molar mass of NC on the molar ratio of nitrite-to-nitrate ions were investigated, and new insights into the understanding of the alkaline denitration mechanism of NCs, underlying this analytical strategy is provided. The method was then tested successfully with various explosive and non-explosive NC-containing samples such as various daily products and smokeless gunpowders. Inherently to its principle exploiting a concentration ratio, this method shows very good repeatability in the determination of nitrogen content in real samples with relative standard deviation (n = 3) inferior to 1.5%, and also provides very significant advantages with respect to sample extraction, analysis time (1h for alkaline hydrolysis, 3 min for electrophoretic separation), which was about 5 times shorter than for the classical Devarda's method, currently used in industry, and safety conditions (no need for preliminary drying NC samples, mild hydrolysis conditions with 1M sodium hydroxide for 1h at 60 °C). PMID:25562808

  17. The effect of the initial reactant molar ratio and doping with Fe3+ on the formation of calcium bilirubinate in water-oil microemulsions

    NASA Astrophysics Data System (ADS)

    Liu, Siyun; Zhu, Jinmiao; Shen, Yuhua; Xie, Anjian; Zhang, Chunyan; Qiu, Lingguang

    2007-07-01

    A series of calcium bilirubinate nanoparticles were synthesized in microemulsions consisting of polyoxyethylene octylphenol ether (Triton X-100), n-hexyl alcohol (n-C6H13OH), cyclohexane (c-C6H12), and an aqueous solution. The particles were characterized by Fourier transform infrared (FT-IR) spectra, powder X-ray diffraction (XRD), inductively coupled plasma atomic emission spectrometry (ICP-AES), transmission electron microscopy (TEM), and zeta potential measurements. The results showed that the initial CaCl2/Na2BR molar ratio and the molar ratio of water to surfactant (ω0) influenced the morphology and microstructure of calcium bilirubinate nanoparticles and the sites of Ca2+ coordination to BR2-. The composition of synthesized calcium bilirubinate was nonstoichiometric. The stability of calcium bilirubinate nanoparticles dispersed in water changes as the Ca2+/BR2- molar ratio and solution pH varied. Dopant Fe2+ ions played a certain role in the simulated mineralization of calcium bilirubinate. A possible mechanism of calcium bilirubinate formation in inverse microemulsions is discussed.

  18. The influence of the molar ratio [H2O]/[Ti(OR)4] on the kinetics of the titanium-oxo-alkoxy clusters nucleation

    NASA Astrophysics Data System (ADS)

    Baroš, Z. Z.; Adnađević, B. K.

    2011-12-01

    The influence of the molar ratio h = [H2O]/[Ti(OR)4] (R = Pr i ) on the kinetics of the titanium-oxo-alkoxy clusters (TOAC) nucleation was studied. Clusters were formed by the titanium tetraisopropoxide Ti(OPr i )4 chemical reaction with H2O in n-propanol solution, with the fixed concentration of Ti(OPr i )4 ( c = 0.04 M), molar ratio h ∈ {11, 14, 17, 20} and temperature T ∈ {298, 308, 318} K. It was determined that the isothermal rate of clusters nucleation is a power law function of the molar ratio h. The kinetic parameter β value changes complexly as h and T change. The value of apparent activation energy of the nucleation process ( E a) decreases with the increase of value h. It was found that nucleation is a reaction with complex kinetics whose elementary stages are hydrolysis Ti(OR)4 to Ti(OR)3OH and formation of titanium-oxo-alkoxy clusters [Ti n + βOβ](OR)4 n + 2β through the alcoxolation reaction.

  19. Manganese-mitigation of cadmium toxicity to seedling growth of Phytolacca acinosa Roxb. is controlled by the manganese/cadmium molar ratio under hydroponic conditions.

    PubMed

    Liu, Huimin; Zhang, Yuxiu; Chai, Tuanyao; Tan, Jinjuan; Wang, Jianwu; Feng, Shanshan; Liu, Geyu

    2013-12-01

    Manganese (Mn) can interact with cadmium (Cd) in environments and influence the toxic effect of Cd on plants. However, few studies have investigated the relationship between the Mn/Cd ratio and plant Cd-toxicity along Cd concentrations. In this paper, we studied the effects of external Mn/Cd molar ratios (0, 10, 30, 50 and 60) on Cd toxicity in the Mn hyperaccumulator and Cd tolerant plant, Phytolacca acinosa Roxb., at three Cd levels (50, 100 and 200 μM) under hydroponic conditions. Our result showed that seedling growth (y) under Cd stress was strongly positively related to the solution Mn/Cd molar ratio (SMCR). The relationship between the two variables under solution Cd concentrations was well explained by the linear regression model y=a+b1 (SMCR)+b2 (Solution-Cd). Increasing SMCR significantly reduced the Cd concentration and increased the Mn concentration in plant tissues. However, seedling growth was consistent with the shoot Mn/Cd molar ratio rather than with the Mn or Cd concentrations in plant tissues. At low levels of SMCR (e.g. 0 and 10), elevation of Mn distribution in shoot tissues might be a mechanism in P. acinosa seedlings to defend against Cd-toxicity. In comparison with low levels of SMCR, high levels of SMCR (e.g. 50 and 60) greatly alleviated lipid peroxidation and plant water-loss, and enhanced photosynthesis. However, the alleviated lipid peroxidation in the Mn-mitigation of Cd toxicity was likely to be the secondary effect resulting from the antagonism between Mn and Cd in the plant. PMID:24095921

  20. Electron paramagnetic resonance study of hydrogen peroxide/ascorbic acid ratio as initiator redox pair in the inulin-gallic acid molecular grafting reaction.

    PubMed

    Arizmendi-Cotero, Daniel; Gómez-Espinosa, Rosa María; Dublán García, Octavio; Gómez-Vidales, Virginia; Dominguez-Lopez, Aurelio

    2016-01-20

    Gallic acid (GA) was grafted onto inulin using the free radicals method, generated by the hydrogen peroxide/ascorbic acid (H2O2/AA) redox pair. Molar ratios of H2O2/AA at 9, 20, 39 and 49 were evaluated by Electron Paramagnetic Resonance in order to find the effect of the oxidation of the inulin and the efficiency in the inulin-gallic acid grafting (IGA). The highest concentration of the inulin macro-radical was obtained with H2O2/AA molar ratios of 20 and 49 with the removal of a hydrogen atom from a methyl group of the inulin fructose monomers. The highest grafting ratio (30.4 mg GA eq/g IGA) was obtained at 9 M of H2O2/AA. UV-Vis, FT-IR-ATR and XDR results confirmed a successful IGA grafting. The efficiency of the grafting reaction depends on the concentration of the macro-radical, it depends on the molar ratio of H2O2/AA, being affected by simultaneous reactions between components of the mixture (H2O2, AA, inulin, GA and eventually atmospheric oxygen) as well. PMID:26572365

  1. Molar gas ratios of air entrapped in ice: A new tool to determine the origin of relict massive ground ice bodies in permafrost

    NASA Astrophysics Data System (ADS)

    Cardyn, Raphaelle; Clark, Ian D.; Lacelle, Denis; Lauriol, Bernard; Zdanowicz, Christian; Calmels, Fabrice

    2007-09-01

    The molar ratios of atmospheric gases change during dissolution in water due to differences in their relative solubilities. We exploited this characteristic to develop a tool to clarify the origin of ice formations in permafrost regions. Extracted from ice, molar gas ratios can distinguish buried glacier ice from intrasedimental ground ice formed by freezing groundwaters. An extraction line was built to isolate gases from ice by melting and trapping with liquid He, followed by analysis of N 2, O 2,, Ar, 18O O2 and 15N N2, by continuous flow mass spectrometry. The method was tested using glacier ice, aufeis ice (river icing) and intrasedimental ground ice from sites in the Canadian Arctic. O 2/Ar and N 2/Ar ratios clearly distinguish between atmospheric gas in glacial ice and gases from intrasedimental ground ice, which are exsolved from freezing water. δ15N N2 and δ18O O2 in glacier ice, aufeis ice and intrasedimental ground ice do not show clear distinguishing trends as they are affected by various physical processes during formation such as gravitational settling, excess air addition, mixing with snow pack, and respiration.

  2. Multi-Molar Absorption of CO2 by the Activation of Carboxylate Groups in Amino Acid Ionic Liquids.

    PubMed

    Chen, Feng-Feng; Huang, Kuan; Zhou, Yan; Tian, Zi-Qi; Zhu, Xiang; Tao, Duan-Jian; Jiang, De-En; Dai, Sheng

    2016-06-13

    A new strategy for multi-molar absorption of CO2 is reported based on activating a carboxylate group in amino acid ionic liquids. It was illustrated that introducing an electron-withdrawing site to amino acid anions could reduce the negative inductive effect of the amino group while simultaneously activating the carboxylate group to interact with CO2 very efficiently. An extremely high absorption capacity of CO2 (up to 1.69 mol mol(-1) ) in aminopolycarboxylate-based amino acid ionic liquids was thus achieved. The evidence of spectroscopic investigations and quantum-chemical calculations confirmed the interactions between two kinds of sites in the anion and CO2 that resulted in superior CO2 capacities. PMID:27136274

  3. Barium recovery by crystallization in a fluidized-bed reactor: effects of pH, Ba/P molar ratio and seed.

    PubMed

    Su, Chia-Chi; Reano, Resmond L; Dalida, Maria Lourdes P; Lu, Ming-Chun

    2014-06-01

    The effects of process conditions, including upward velocity inside the column, the amount of added seed and seed size, the pH value of the precipitant or the phosphate stream and the Ba/P molar ratio in a fluidized-bed reactor (FBR) were studied with a view to producing BaHPO₄ crystals of significant size and maximize the removal of barium. XRD were used to identify the products that were collected from the FBR. Experimental results show that an upward velocity of 48 cmmin(-1) produced the largest BaHPO₄ crystals with a size of around 0.84-1.0mm. The addition of seed crystals has no effect on barium removal. The use of a seed of a size in the ranges unseeded<0.149-0.29 mm<0.149 mm<0.29-0.42 mm produced increasing amounts of increasingly large crystals. The largest BaHPO₄ crystals were obtained at pH 8.4-8.8 with a Ba/P molar ratio of 1.0. In the homogeneous and heterogeneous processes, around 98% of barium was removed at pH 8.4-8.6 and [Ba]/[P]=1.0. The XRD results show that a significant amount of barium phosphate (Ba₃(PO₄)₂) was obtained at pH 11. The compounds BaHPO₄ and BaO were present at a pH of below 10. PMID:24462085

  4. Novel Microwave-Assisted Synthesis of Poly(D,L-lactide): The Influence of Monomer/Initiator Molar Ratio on the Product Properties

    PubMed Central

    Nikolic, Ljubisa; Ristic, Ivan; Adnadjevic, Borivoj; Nikolic, Vesna; Jovanovic, Jelena; Stankovic, Mihajlo

    2010-01-01

    Poly(D,L-lactide) synthesis using tin(II) 2-ethylhexanoate initiated ring-opening polymerization (ROP) takes over 30 hours in bulk at 120 °C. The use of microwave makes the same bulk polymerization process with the same initiator much faster and energy saving, with a reaction time of about 30 minutes at 100 °C. Here, the poly(lactide) synthesis was done in a microwave reactor, using frequency of 2.45 GHz and maximal power of 150 W. The reaction temperature was controlled via infra-red system for in-bulk-measuring, and was maintained at 100 °C. Different molar ratios of monomer and initiator, [M]/[I], of 1,000, 5,000 and 10,000 were used. The achieved average molar masses for the obtained polymers (determined by gel permeation chromatography) were in the interval from 26,700 to 112,500 g/mol. The polydispersion index was from 2.436 to 3.425. For applicative purposes, the obtained material was purified during the procedure of microsphere preparation. Microspheres were obtained by spraying a fine fog of polymer (D,L-lactide) solution in tetrahydrofuran into the water solution of poly(vinyl alcohol) with intensive stirring. PMID:22399924

  5. Deciduous molar hypomineralization and molar incisor hypomineralization.

    PubMed

    Elfrink, M E C; ten Cate, J M; Jaddoe, V W V; Hofman, A; Moll, H A; Veerkamp, J S J

    2012-06-01

    This study was embedded in the Generation R Study, a population-based prospective cohort study from fetal life until young adulthood. This study focused on the relationship between Deciduous Molar Hypomineralization (DMH) and Molar Incisor Hypomineralization (MIH). First permanent molars develop during a period similar to that of second primary molars, with possible comparable risk factors for hypomineralization. Children with DMH have a greater risk of developing MIH. Clinical photographs of clean, moist teeth were taken with an intra-oral camera in 6,161 children (49.8% girls; mean age 74.3 mos, SD ± 5.8). First permanent molars and second primary molars were scored with respect to DMH or MIH. The prevalence of DMH and MIH was 9.0% and 8.7% at child level, and 4.0% and 5.4% at tooth level. The Odds Ratio for MIH based on DMH was 4.4 (95% CI, 3.1-6.4). The relationship between the occurrence of DMH and MIH suggests a shared cause and indicates that, clinically, DMH can be used as a predictor for MIH. PMID:22370445

  6. Rats show molar sensitivity to different aspects of random-interval-with-linear-feedback-functions and random-ratio schedules.

    PubMed

    Reed, Phil

    2015-10-01

    Three experiments examined the impact of various aspects of reinforcement contingencies on responding maintained by free-operant schedules by food-deprived rats. Experiment 1 demonstrated that random interval (RI) and random-interval-with-positive-response-reinforcer-feedback (RI+) schedules maintained similar rates of responding at a variety of reinforcer frequencies. Experiment 2 demonstrated that a random ratio (RR) schedule maintained higher rates than RI or RI+ schedules, except at high rates of reinforcement, where response rates were similar on all schedules. Experiment 3 again demonstrated that RR schedules produced higher response rates than either RI or RI+ schedules, but modification of the RI+ schedule to prevent ratio strain enhanced response rates relative to an RI schedule. Together these results reveal a pattern of interacting factors in schedule controlled behavior: at high rates of reinforcement, this factor overrides the impact of other controlling factors, but as reinforcement rate decreases the joint impact of interresponse times reinforcement, response-reinforcer feedback functions, and ratio strain are observed. PMID:25915752

  7. Effects of the Fe3+/Sr2+ molar ratio on the exchange-coupling of the composite and single-phase SrFe12O19

    NASA Astrophysics Data System (ADS)

    Xu, Yuanfeng; Ma, Yongqing; Zhang, Xian; Zheng, Ganhong; Dai, Zhenxiang; Ma, Qian; Zan, Fenlian; Li, Guang; Wu, Mingzai

    2013-04-01

    It has been systematically investigated about the magnetic properties of the composite and single-phase SrFe12O19 prepared with the precursor of different Fe3+/Sr2+ molar ratios of 12:1, 11:1 and 10:1, respectively. With increasing the calcinations temperature, the coercivity of all samples decreases which can be determined by the stress model. The δm(H) results indicate that the intergrain exchangecoupling interaction exists both in composite and in single-phase SrFe12O19, resulting in the remanence magnetization enhancement, and the magnetostatic interaction become dominant in the samples with higher calcinations temperatures. The irreversible susceptibilities χirr(H) curves show that there may exhibit the exchange-spring behavior in the composite SrFe12O19 with more soft magnetic γ-Fe2O3, and the irreversible switching field may be qualitatively used to determine the coercivity magnitude.

  8. Glycerol capped PbS/CdS core/shell nanoparticles at different molar ratio and its application in biosensors: An optical properties study

    NASA Astrophysics Data System (ADS)

    Das, D.; Hussain, A. M. P.

    2016-05-01

    Glycerol capped PbS/CdS core/shell type nanoparticles fabricated with two different molar ratios are characterized for study of structural and optical properties. The X-ray diffraction (XRD) pattern exhibits cubic phased polycrystalline nanocrystals. The calculated grain sizes from Williamson-Hall plot were found to be around 6 nm with increased strain. HRTEM investigation confirms the formation of core/shell nanostructures and the sizes of the particles were found to be around 7 nm which is in good agreement with the results of the W-H plot. An increase of band gap with the decrease in precursor concentration is confirmed from the blue shift in the absorption spectra and also from Tauc plot. A clear blue shifted intense emission is observed in the photoluminescence spectra with decrease in particle size. Intense luminescence from the core/shell nanostructure may be applied in bio labelling and biosensors.

  9. Chromatography-based methods for determining molar extinction coefficients of cytotoxic payload drugs and drug antibody ratios of antibody drug conjugates.

    PubMed

    Wang, Chunlei; Chen, Sike; Caceres-Cortes, Janet; Huang, Richard Y-C; Tymiak, Adrienne A; Zhang, Yingru

    2016-07-15

    UV spectrophotometry is widely used to determine the molar extinction coefficients (MECs) of cytotoxic drugs as well as the drug antibody ratios (DARs) of antibody drug conjugates (ADCs). However, the unknown purity of a drug due to interfering impurities can lead to erroneous MECs and DARs. Hence, reliable methods to accurately determine purity and the MECs of drugs with limited quantity is urgently needed in Drug Discovery. Such a method has been developed. It achieves absolute purity and accurate MEC determination by a single automated HPLC analysis that uses less than 5μg of material. Specifically, analytical HPLC separation with online UV detection was used to resolve impurities and measure absorbance from only the compound of interest. Simultaneously, an online chemiluminescence nitrogen detector (CLND) was used to determine the concentration of the analyte. The MECs were then calculated from the absorbance and concentration results. The accuracy of the method was demonstrated using caffeine and a commercial cytotoxic drug, DM1. This approach is particularly suited to analyzing mixtures or samples with low purities. Excellent reproducibility was demonstrated by analyzing a proprietary drug with linker synthesized from different batches with very different levels of purity. In addition, the MECs of drug with linker, along with ADC peak areas measured from size exclusion chromatography (SEC), were used to calculate DARs for 21 in-house ADCs. The DAR results were consistent with those obtained by MS analysis. PMID:27286648

  10. Influence of ZnO seed layer precursor molar ratio on the density of interface defects in low temperature aqueous chemically synthesized ZnO nanorods/GaN light-emitting diodes

    NASA Astrophysics Data System (ADS)

    Alnoor, Hatim; Pozina, Galia; Khranovskyy, Volodymyr; Liu, Xianjie; Iandolo, Donata; Willander, Magnus; Nur, Omer

    2016-04-01

    Low temperature aqueous chemical synthesis (LT-ACS) of zinc oxide (ZnO) nanorods (NRs) has been attracting considerable research interest due to its great potential in the development of light-emitting diodes (LEDs). The influence of the molar ratio of the zinc acetate (ZnAc): KOH as a ZnO seed layer precursor on the density of interface defects and hence the presence of non-radiative recombination centers in LT-ACS of ZnO NRs/GaN LEDs has been systematically investigated. The material quality of the as-prepared seed layer as quantitatively deduced by the X-ray photoelectron spectroscopy is found to be influenced by the molar ratio. It is revealed by spatially resolved cathodoluminescence that the seed layer molar ratio plays a significant role in the formation and the density of defects at the n-ZnO NRs/p-GaN heterostructure interface. Consequently, LED devices processed using ZnO NRs synthesized with molar ratio of 1:5 M exhibit stronger yellow emission (˜575 nm) compared to those based on 1:1 and 1:3 M ratios as measured by the electroluminescence. Furthermore, seed layer molar ratio shows a quantitative dependence of the non-radiative defect densities as deduced from light-output current characteristics analysis. These results have implications on the development of high-efficiency ZnO-based LEDs and may also be helpful in understanding the effects of the ZnO seed layer on defect-related non-radiative recombination.

  11. Time-dependent fracture probability of bilayer, lithium-disilicate-based glass-ceramic molar crowns as a function of core/veneer thickness ratio and load orientation

    PubMed Central

    Anusavice, Kenneth J.; Jadaan, Osama M.; Esquivel–Upshaw, Josephine

    2013-01-01

    Recent reports on bilayer ceramic crown prostheses suggest that fractures of the veneering ceramic represent the most common reason for prosthesis failure. Objective The aims of this study were to test the hypotheses that: (1) an increase in core ceramic/veneer ceramic thickness ratio for a crown thickness of 1.6 mm reduces the time-dependent fracture probability (Pf) of bilayer crowns with a lithium-disilicate-based glass-ceramic core, and (2) oblique loading, within the central fossa, increases Pf for 1.6-mm-thick crowns compared with vertical loading. Materials and methods Time-dependent fracture probabilities were calculated for 1.6-mm-thick, veneered lithium-disilicate-based glass-ceramic molar crowns as a function of core/veneer thickness ratio and load orientation in the central fossa area. Time-dependent fracture probability analyses were computed by CARES/Life software and finite element analysis, using dynamic fatigue strength data for monolithic discs of a lithium-disilicate glass-ceramic core (Empress 2), and ceramic veneer (Empress 2 Veneer Ceramic). Results Predicted fracture probabilities (Pf) for centrally-loaded 1,6-mm-thick bilayer crowns over periods of 1, 5, and 10 years are 1.2%, 2.7%, and 3.5%, respectively, for a core/veneer thickness ratio of 1.0 (0.8 mm/0.8 mm), and 2.5%, 5.1%, and 7.0%, respectively, for a core/veneer thickness ratio of 0.33 (0.4 mm/1.2 mm). Conclusion CARES/Life results support the proposed crown design and load orientation hypotheses. Significance The application of dynamic fatigue data, finite element stress analysis, and CARES/Life analysis represent an optimal approach to optimize fixed dental prosthesis designs produced from dental ceramics and to predict time-dependent fracture probabilities of ceramic-based fixed dental prostheses that can minimize the risk for clinical failures. PMID:24060349

  12. Surface morphology, optical, and electrochromic properties of nanostructured nickel ferrite (NiFe2O4) prepared by sol-gel method: effects of Ni/Fe molar ratios

    NASA Astrophysics Data System (ADS)

    Bazhan, Z.; Ghodsi, F. E.; Mazloom, J.

    2016-05-01

    Nanostructured nickel ferrite (NF) was prepared by the sol-gel method and calcined at 500 °C for 2 h. The effect of Ni/Fe molar ratios (0, 10, 30, 50 %) on structural, morphological, compositional, optical, and magnetic properties of samples was investigated using analytical tools. XRD patterns indicated the presence of hematite phase in the pure and 10 % NF samples. The samples of 30 and 50 % Ni/Fe molar ratios showed the formation of nickel ferrite structure. Using AFM images, power spectrum density analysis were performed for Ni/Fe with different molar ratio. Also the effect of thickness on morphology of 30 % sample was studied. The fractal dimension increases by increasing the Ni/Fe molar ratio. Optical parameters were evaluated by theoretical approach, and compositional dependence of these parameters was discussed comprehensively. Band gap narrowing was observed in nickel ferrite thin films by increasing the nickel contents from 10 to 50 %. Magnetic analysis revealed that increasing nickel content improved the saturation magnetization. Electrochemical measurements indicated that NF thin films have higher total charge density rather than Fe2O3 thin films and the ion storage capacitance of NF thin films increased by increasing the Ni/Fe content.

  13. From aquatic to terrestrial food webs: decrease of the docosahexaenoic acid/linoleic acid ratio.

    PubMed

    Koussoroplis, Apostolos-Manuel; Lemarchand, Charles; Bec, Alexandre; Desvilettes, Christian; Amblard, Christian; Fournier, Christine; Berny, Philippe; Bourdier, Gilles

    2008-05-01

    Fatty acid composition of the adipose tissue of six carnivorous mammalian species (European otter Lutra lutra, American mink Mustela vison, European Mink Mustela lutreola, European polecat Mustela putorius, stone marten Martes foina and European wild cat Felis silvestris) was studied. These species forage to differing degrees in aquatic and terrestrial food webs. Fatty acid analysis revealed significant differences in polyunsaturated fatty acid composition between species. More specifically, our results underline a gradual significant decrease in the docosahexaenoic acid (DHA)/linoleic acid (LNA) ratio of carnivore species as their dependence on aquatic food webs decreases. In conclusion, the use of the DHA/LNA ratio in long-term studies is proposed as a potential proxy of changes in foraging behaviour of semi-aquatic mammals. PMID:18335265

  14. Unusual stable isotope ratios in amino acid and carboxylic acid extracts from the Murchison meteorite

    NASA Technical Reports Server (NTRS)

    Epstein, S.; Krishnamurthy, R. V.; Cronin, J. R.; Pizzarello, S.; Yuen, G. U.

    1987-01-01

    The isotopic composition of hydrogen, nitrogen, and carbon in amino acid and monocarboxylic acid extracts from the Murchison meteorite has been determined. The unusually high D/H and N-15/N-14 ratios in the amino acid fraction are uniquely characteristic of known interstellar organic materials. The delta D value of the monocarboxylic acid fraction is lower but still consistent with an interstellar origin. These results confirm the extraterrestrial origin of both classes of compound and provide the first evidence suggesting a direct relationship between the massive organosynthesis occurring in interstellar clouds and the presence of prebiotic compounds in primitive planetary bodies.

  15. The effect of Cu/Zn molar ratio on CO{sub 2} hydrogenation over Cu/ZnO/ZrO{sub 2}/Al{sub 2}O{sub 3} catalyst

    SciTech Connect

    Shaharun, Salina E-mail: maizats@petronas.com.my; Shaharun, Maizatul S. E-mail: maizats@petronas.com.my; Taha, Mohd F.; Mohamad, Dasmawati

    2014-10-24

    Catalytic hydrogenation of carbon dioxide (CO{sub 2}) to methanol is an attractive way to recycle and utilize CO{sub 2}. A series of Cu/ZnO/Al{sub 2}O{sub 3}/ZrO{sub 2} catalysts (CZAZ) containing different molar ratios of Cu/Zn were prepared by the co-precipitation method and investigated in a stirred slurry autoclave system. The catalysts were characterized by temperature-programmed reduction (TPR), field emission scanning electron microscopy-energy dispersive analysis (FESEM-EDX), X-ray diffraction (XRD) and N{sub 2} adsorption-desorption. Higher surface area, SA{sub BET} values (42.6–59.9 m{sup 2}/g) are recorded at low (1) and high (5) Cu/Zn ratios with the minimum value of 35.71 m{sup 2}/g found for a Cu/Zn of 3. The reducibility of the metal oxides formed after calcination of catalyst samples was also affected due to change in metal-support interaction. At a low reaction temperature of 443 K, total gas pressure of 3.0 MPa and 0.1 g/mL of the CZAZ catalyst, the selectivity to methanol decreased as the Cu/Zn molar ratio increased, and the maximum selectivity of 67.73 was achieved at Cu/Zn molar ratio of 1. With a reaction time of 3h, the best performing catalyst was CZAZ75 with Cu/Zn molar ratio of 5 giving methanol yield of 79.30%.

  16. Development of the Oleic Acid/Linoleic Acid Ratio in High-Oleic Valencia Market Type Peanuts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The major fatty acids in peanuts are oleic acid (O), a monounsaturated omega-9, and linoleic acid (L), a polyunsaturated omega-6. Peanuts containing these two fatty acids in a ratio (O/L) above 9 are known as high oleic (HO). Normal oleic (NO) peanuts are those with an O/L ratio less than 9. HO pean...

  17. A mutant form of 3-ketosteroid-Δ(1)-dehydrogenase gives altered androst-1,4-diene-3, 17-dione/androst-4-ene-3,17-dione molar ratios in steroid biotransformations by Mycobacterium neoaurum ST-095.

    PubMed

    Shao, Minglong; Zhang, Xian; Rao, Zhiming; Xu, Meijuan; Yang, Taowei; Li, Hui; Xu, Zhenghong; Yang, Shangtian

    2016-05-01

    Mycobacterium neoaurum ST-095 and its mutant M. neoaurum JC-12, capable of transforming phytosterol to androst-1,4-diene-3,17-dione (ADD) and androst-4-ene-3,17-dione (AD), produce very different molar ratios of ADD/AD. The distinct differences were related to the enzyme activity of 3-ketosteroid-Δ(1)-dehydrogenase (KSDD), which catalyzes the C1,2 dehydrogenation of AD to ADD specifically. In this study, by analyzing the primary structure of KSDDI (from M. neoaurum ST-095) and KSDDII (from M. neoaurum JC-12), we found the only difference between KSDDI and KSDDII was the mutation of Val(366) to Ser(366). This mutation directly affected KSDD enzyme activity, and this result was confirmed by heterologous expression of these two enzymes in Bacillus subtilis. Assay of the purified recombinant enzymes showed that KSDDII has a higher C1,2 dehydrogenation activity than KSDDI. The functional difference between KSDDI and KSDDII in phytosterol biotransformation was revealed by gene disruption and complementation. Phytosterol transformation results demonstrated that ksdd I and ksdd II gene disrupted strains showed similar ADD/AD molar ratios, while the ADD/AD molar ratios of the ksdd I and ksdd II complemented strains were restored to their original levels. These results proved that the different ADD/AD molar ratios of these two M. neoaurum strains were due to the differences in KSDD. Finally, KSDD structure analysis revealed that the Val(366)Ser mutation could possibly play an important role in stabilizing the active center and enhancing the interaction of AD and KSDD. This study provides a reliable theoretical basis for understanding the structure and catalytic mechanism of the Mycobacteria KSDD enzyme. PMID:26886757

  18. Effect of OH-/Al3+ and Si/Al molar ratios on the coagulation performance and residual Al speciation during surface water treatment with poly-aluminum-silicate-chloride (PASiC).

    PubMed

    Yang, Zhonglian; Gao, Baoyu; Xu, Weiying; Cao, Baichuan; Yue, Qinyan

    2011-05-15

    Coagulation performance, mechanism of poly-aluminum-silicate-chloride (PASiC) and residual Al speciation in the effluent with respect to a specific surface water treatment in China were comprehensively investigated in this study. The impact of OH(-)/Al(3+) and Si/Al molar ratios on the coagulation performance, mechanism and residual Al speciation of PASiC in surface water treatment was discussed as a function of coagulant dosage. It was intended to provide an insight into the relationship between coagulation performance and residual Al. Experimental results revealed that when OH(-)/Al(3+) molar ratio = 2.00 and Si/Al molar ratio = 0.0500 in PASiC coagulant, PASiC exhibited beneficial coagulation property and relatively lower content of residual Al. Surface bridging and entrapment was more effective compared with charge neutralization during the specific surface water treatment. The majority of residual Al in the effluent existed in the form of insoluble suspended or particulate Al. Dissolved organically bound Al was almost the major speciation in dissolved Al and dissolved inorganically bound monomeric Al was the only component in dissolved monomeric Al. Al in PASiC remained abundant at lower dosages and residual Al concentration could be effectively reduced at the dosages of 12.0-15.0mg/L as Al. PMID:21376461

  19. Theoretical insight into the binding energy and detonation performance of ε-, γ-, β-CL-20 cocrystals with β-HMX, FOX-7, and DMF in different molar ratios, as well as electrostatic potential.

    PubMed

    Feng, Rui-Zhi; Zhang, Shu-Hai; Ren, Fu-de; Gou, Rui-Jun; Gao, Li

    2016-06-01

    Molecular dynamics method was employed to study the binding energies on the selected crystal planes of the ε-, γ-, β-conformation 2,4,6,8,10,12-hexanitrohexaazaisowurtzitane (ε-, γ-, β-CL-20) cocrystal explosives with 1,1-diamino-2,2-dinitroethylene (FOX-7), 1,3,5,7-tetranitro- 1,3,5,7-tetrazacyclooctane with β-conformation (β-HMX) and N,N-dimethylformamide (DMF) in different molar ratios. The oxygen balance, density, detonation velocity, detonation pressure, and surface electrostatic potential were analyzed. The results indicate that the binding energies E b (*) and stabilities are in the order of 1:1 > 2:1 > 3:1 > 5:1 > 8:1 (CL-20:FOX-7/β-HMX/DMF). The values of E b (*) and stabilities of the energetic-nonenergetic CL-20/DMF cocrystals are far larger than those of the energetic-energetic CL-20/FOX-7 and CL-20/β-HMX, and those of CL-20/β-HMX are the smallest. For CL-20/FOX-7 and CL-20/β-HMX, the largest E b (*) appears in the cocrystals with the 1:1, 1:2 or 1:3 molar ratio, and the stabilities of the cocrystals with the excess ratio of CL-20 are weaker than those in the cocrystals with the excess ratio of FOX-7 or β-HMX. In CL-20/FOX-7, CL-20 prefers adopting the γ-form, and ε-CL-20 is the preference in CL-20/β-HMX, and ε-CL-20 and β-CL-20 can be found in CL-20/DMF. The CL-20/FOX-7 and CL-20/β-HMX cocrystals with low molar ratios can meet the requirements of low sensitive high energetic materials. Surface electrostatic potential reveals the nature of the sensitivity change upon the cocrystal formation. Graphical Abstract MD method was employed to study the binding energies on the selected crystal planes in the ε-, γ-, β-CL-20 cocrystals with FOX-7, β-HMX and DMF in different molar ratios. Surface electrostatic potential reveals the nature of the sensitivity change in cocrystals. PMID:27168198

  20. Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

    PubMed Central

    Abdul Razak, Rafiza; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Ismail, Khairul Nizar; Hardjito, Djwantoro; Yahya, Zarina

    2015-01-01

    This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced. PMID:26006238

  1. Fractionation of residual Al in natural water treatment from reservoir with poly-aluminum-silicate-chloride (PASiC): effect of OH/Al, Si/Al molar ratios and initial pH.

    PubMed

    Yang, Zhonglian; Gao, Baoyu; Wang, Yan; Zhao, Yaqin; Yue, Qinyan

    2012-01-01

    An aluminum fractionation study was conducted for a surface reservoir water treatment to understand the performance of poly-aluminum-silicate-chloride (PASiC) in terms of the residual Al fractions as a function of initial pH. The coagulation performance expressed as turbidity and organic matter removal was established as supporting data. Some extra data were evaluated in terms of the residual Al ratio of the composite PASiC coagulant. The main residual Al sources were the Al fractions derived from the use of PASiC. The turbidity and organic matter removal ability was optimal at initial pH 6.00-7.00, while the concentrations of various residual Al species and the residual Al ratio of PASiC were minimal at an initial pH range of 7.00-8.00. Under the conditions of OH/Al molar ratio = 2.00 and Si/Al molar ratio = 0.05, PASiC had superior coagulation performance and comparatively low residual Al concentrations. The Al fraction in the composite PASiC coagulant seldom remained under such conditions. Experimental data also indicated that the suspended (filterable) Al fraction was the dominant species, and organic-bound or organo-Al complex Al was considered to be the major species of dissolved Al in water treated by PASiC coagulation. Additionally, the dissolved inorganic monomeric Al species dominated the dissolved monomeric Al fraction. PMID:23534222

  2. Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer.

    PubMed

    Razak, Rafiza Abdul; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Ismail, Khairul Nizar; Hardjito, Djwantoro; Yahya, Zarina

    2015-01-01

    This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced. PMID:26006238

  3. THERMAL AND SPECTROSCOPIC ANALYSES OF NEXT GENERATION CAUSTIC SIDE SOLVENT EXTRACTION SOLVENT CONTACTED WITH 3, 8, AND 16 MOLAR NITRIC ACID

    SciTech Connect

    Fondeur, F.; Fink, S.

    2011-09-30

    A new solvent system referred to as Next Generation Solvent or NGS, has been developed at Oak Ridge National Laboratory for the removal of cesium from alkaline solutions in the Caustic Side Solvent Extraction process. NGS is proposed for deployment at MCU and at the Salt Waste Processing Facility. This work investigated the chemical compatibility between NGS and 16 M, 8 M, and 3 M nitric acid from contact that may occur in handling of analytical samples from MCU or, for 3 M acid, which may occur during contactor cleaning operations at MCU. This work shows that reactions occurred between NGS components and the high molarity nitric acid. In the case of 16 M and 8 M nitric acid, initially organo-nitrate groups are generated and attach to the modifier and that with time oxidation reactions convert the modifier into a tarry substance with gases (NO{sub x} and possibly CO) evolving. Calorimetric analysis of the organonitrate revealed the reaction products are not explosive nor will they deflagrate. NGS exposure to 3 M nitric acid resulted in much slower reaction kinetics and that the generated products were not energetic. We recommended conducting Accelerated Rate calorimetry on the materials generated in the 16 M and 8 M nitric acid test. Also, we recommend continue monitoring of the samples contacting NGS with 3 M nitric acid.

  4. Thermal And Spectroscopic Analyses Of Next Generation Caustic Side Solvent Extraction Solvent Contacted With 3, 8, And 16 Molar Nitric Acid

    SciTech Connect

    Fondeur, F. F.; Fink, S. D.

    2011-12-07

    A new solvent system referred to as Next Generation Solvent or NGS, has been developed at Oak Ridge National Laboratory for the removal of cesium from alkaline solutions in the Caustic Side Solvent Extraction process. The NGS is proposed for deployment at MCU{sup a} and at the Salt Waste Processing Facility. This work investigated the chemical compatibility between NGS and 16 M, 8 M, and 3 M nitric acid from contact that may occur in handling of analytical samples from MCU or, for 3 M acid, which may occur during contactor cleaning operations at MCU. This work shows that reactions occurred between NGS components and the high molarity nitric acid. Reaction rates are much faster in 8 M and 16 M nitric acid than in 3 M nitric acid. In the case of 16 M and 8 M nitric acid, the nitric acid reacts with the extractant to produce initially organo-nitrate species. The reaction also releases soluble fluorinated alcohols such as tetrafluoropropanol. With longer contact time, the modifier reacts to produce a tarry substance with evolved gases (NO{sub x} and possibly CO). Calorimetric analysis of the reaction product mixtures revealed that the organo-nitrates reaction products are not explosive and will not deflagrate.

  5. Aspartame and sucrose produce a similar increase in the plasma phenylalanine to large neutral amino acid ratio in healthy subjects.

    PubMed

    Burns, T S; Stargel, W W; Tschanz, C; Kotsonis, F N; Hurwitz, A

    1991-01-01

    Aspartame (L-aspartyl-L-phenylalanine methyl ester) consumption has been postulated to increase brain phenylalanine levels by increasing the molar ratio of the plasma phenylalanine concentration to the sum of the plasma concentrations of the other large neutral amino acids (Phe/LNAA). Dietary manipulations with carbohydrate or protein can also produce changes in the Phe/LNAA value. To compare the effects of aspartame and carbohydrate on Phe/LNAA, beverages sweetened with aspartame, sucrose, and aspartame plus sucrose, and unsweetened beverage were ingested by 8 healthy, fasted subjects in a randomized, four-way crossover design. The beverages were sweetened with an amount of aspartame (500 mg) and/or sucrose (100 g) approximately equivalent to that used to sweeten 1 liter of soft drink. The baseline-corrected plasma Phe/LNAA values did not differ significantly following ingestion of aspartame or sucrose. Following aspartame alone, the high mean ratio increased 26% over baseline 1 h after ingestion. Following sucrose alone, the high mean ratio increased 19% at 2.5 h. Sucrose increased the Phe/LNAA value due to an insulin-mediated decrease in the plasma LNAA, while aspartame increased the ratio by increasing the plasma Phe concentration. These findings indicate that similar increases in plasma Phe/LNAA occur when healthy, fasting subjects ingest amounts of equivalent sweetness of sucrose or aspartame. PMID:1771173

  6. Spectrophotometric determination of the oxygen to uranium ratio in uranium oxides based on dissolution in sulphuric acid.

    PubMed

    Murty, B N; Yadav, R B; Ramamurthy, C K; Syamundar, S

    1991-11-01

    The oxygen to uranium ratio in uranium oxides such as U(3)O(8), UO(2+x) powders and UO(2) fuel pellets has been determined by a new spectrophotometric method. The method can be used for determination of O/U ratio in UO(2) pellets and powders on a routine basis. In the described method, uranium oxides in the powder form are dissolved in 2M sulphuric acid containing a few drops of HF. The concentrations of U(IV) and U(VI) are directly determined by means of the absorbances of these species at different wavelengths. For determination of the O/U ratio in U(3)O(8) powder samples, 630 and 310 nm are the wavelengths chosen for U(IV) and U(VI), respectively. For UO(2+x) powder, where the O/U ratio lies between 2.04 to 2.15, U(IV) and U(VI) are determined at 630 and 300 nm respectively, whereas for UO(2) fuel pellets, where the O/U ratio is less than 2.01, 535 and 285 nm are used. The molar absorptivity of U(IV) at 630 and 535 nm is 21.4 and 6.8 l.mole(-1).cm(-1) and that of U(VI) at 310, 300 and 285 nm is 178.1, 278.6 and 585 l.mole(-1).cm(-1), respectively. Standard deviations of +/-0.002 O/U ratio units for pellets and +/-0.004 O/U ratio units for powders have been achieved. PMID:18965306

  7. Total and free valproic acid: plasma level/dose ratio in monotherapy.

    PubMed

    Abadín, J A; Durán, J A; Sánchez, A; Serrano, J S

    1991-04-01

    Free plasma level/dose ratio of valproic acid (L/D-F) can be more effective than total plasma level/dose ratio (L/D-T) in adjusting dosage regimens. The influence of age, dose, and plasma concentration have been studied on L/D-T and L/D-F ratios. L/D-T and L/D-F ratios from 67 outpatients under long-term monotherapy were obtained. Analytical data was carried out by fluorescent polarized immunoassay. L/D-T and L/D-F ratios do not vary according to age. L/D-T and L/D-F ratios decreased while the dosage increased; both ratios increased with an increase in total plasma level of valproic acid. Significant differences were found between L/D-T and L/D-F ratios. Dose and interindividual variations are the factors which most influence L/D ratios of valproic acid. PMID:2051846

  8. Efficient in vitro inhibition of HIV-1 gag reverse transcription by peptide nucleic acid (PNA) at minimal ratios of PNA/RNA.

    PubMed Central

    Koppelhus, U; Zachar, V; Nielsen, P E; Liu, X; Eugen-Olsen, J; Ebbesen, P

    1997-01-01

    We have tested the inhibitory potential of peptide nucleic acid (PNA) on in vitro reverse transcription of the HIV-1 gag gene. PNA was designed to target different regions of the HIV-1 gag gene and the effect on reverse transcription by HIV-1, MMLV and AMV reverse transcriptases (RTs) was investigated. We found that a bis-PNA (parallel antisense 10mer linked to antiparallel antisense 10mer) was superior to both the parallel antisense 10mer and antiparallel antisense 10mer in inhibiting reverse transcription of the gene, thus indicating triplex formation at the target sequence. A complete arrest of reverse transcription was obtained at approximately 6-fold molar excess of the bis-PNA with respect to the gag RNA. At this molar ratio we found no effect on in vitro translation of gag RNA. A 15mer duplex-forming PNA was also found to inhibit reverse transcription at very low molar ratios of PNA/ gag RNA. Specificity of the inhibition of reverse transcription by PNA was confirmed by RNA sequencing, which revealed that all tested RTs were stopped by the PNA/RNA complex at the predicted site. We propose that the effect of PNA is exclusively due to steric hindrance, as we found no signs of RNA degradation that would indicate PNA-mediated RNase H activation of the tested RTs. In conclusion, PNA appears to have a potential to become a specific and efficient inhibitor of reverse transcription in vivo , provided sufficient intracellular levels are achievable. PMID:9153317

  9. Low Temperature Heat Capacities and Standard Molar Enthalpy of Formation of 2-Pyrazinecarboxylic Acid (C5H4N2O2)(s).

    PubMed

    Kong, Yu-Xia; Di, You-Ying; Yang, Wei-Wei; Gao, Sheng-Li; Tan, Zhi-Cheng

    2010-06-01

    Low-temperature heat capacities of 2-pyrazinecarboxylic acid (C5H4N2O2)(s) were measured by a precision automated adiabatic calorimeter over the temperature range from 78 to 400 K. A polynomial equation of heat capacities as a function of temperature was fitted by least squares method. Based on the fitted polynomial, the smoothed heat capacities and thermodynamic functions of the compound relative to the standard reference temperature 298.15 K were calculated and tabulated at 10 K intervals. The constant-volume energy of combustion of the compound at T = 298.15 K was measured by a precision rotating-bomb combustion calorimeter to be ΔcU = -(17839.40 ± 7.40) J g-1. The standard molar enthalpy of combustion of the compound was determined to be ΔcH0m = -(2211.39 ± 0.92) KJ mol-1, according to the definition of combustion enthalpy. Finally, the standard molar enthalpy of formation of the compound was calculated to be ΔfH0m = -(327.82 ± 1.13) kJ mol-1 in accordance with Hess law. PMID:24061733

  10. Mercury and Selenium in Muscle and Target Organs of Scalloped Hammerhead Sharks Sphyrna lewini of the SE Gulf of California: Dietary Intake, Molar Ratios, Loads, and Human Health Risks.

    PubMed

    Bergés-Tiznado, Magdalena E; Márquez-Farías, Fernando; Lara-Mendoza, Raúl E; Torres-Rojas, Yassir E; Galván-Magaña, Felipe; Bojórquez-Leyva, Humberto; Páez-Osuna, Federico

    2015-11-01

    Selenium and mercury were evaluated in muscle, liver, kidney, brain, and the stomach contents of juvenile scalloped hammerhead shark Sphyrna lewini. Se:Hg molar ratios were calculated. The average Hg levels in muscle ranged from 0.12 to 1.17 μg/g (wet weight); Hg was <0.39 μg/g in liver and kidneys and <0.19 μg/g in brain. The lowest value of Se was found in muscle (0.4 μg/g) and the highest in kidney (26.7 μg/g). An excess of Se over Hg was found, with Se:Hg molar ratios >1. Correlations were found for Hg in muscle with size, age, and weight, and also for Hg in liver with size, age, and weight. Hg in muscle was significantly positive correlated to Hg in brain as well as Hg in liver was correlated to Hg in kidney. The highest Hg in preys was for carangid fishes; scombrid and carangid fishes contributed with the highest Se levels. Results suggest that more than 98 % of the total Hg and 62 % of Se end up in muscle and might be affected by factors, such as geographical area, age, size, and feeding habits. The muscle of S. lewini should be consumed by people cautiously so as not to exceed the recommended intake per week. PMID:26369650

  11. Interactions of valproic acid with carbamazepine and its metabolites' concentrations, concentrations ratios, and level/dose ratios in epileptic children.

    PubMed

    Liu, H; Delgado, M R; Browne, R H

    1995-02-01

    In two groups of epileptic children receiving carbamazepine (CBZ) therapy with or without valproic acid (VPA) comedication, we investigate the drug interactions of VPA on serum CBZ and its metabolites' concentrations, concentration ratios, and level/dose ratios. Serum total and free CBZ-10, 11-epoxide (CBZ-E) concentrations are significantly increased in patients taking CBZ plus VPA, together with higher CBZ-E/CBZ concentration ratios and CBZ-E level/dose ratios. These results reflect the accumulation of CBZ-E. The decreased concentration ratios of trans-10, 11-dihydroxy-10, 11-dihydro-CBZ (CBZ-H)/CBZ-E observed in patients taking CBZ plus VPA suggest an inhibition in the biotransformation from CBZ-E to CBZ-H. Significant negative correlations are found between serum VPA level and CBZ-H/CBZ-E concentration ratios, indicating that the inhibition of CBZ-E hydrolysis by VPA may depend on the concentration of VPA (total or free CBZ-H/CBZ-E concentration ratio = [formula: see text], respectively). VPA concentration also shows significant positive correlations with CBZ-E and CBZ level/dose ratios. Patients taking CBZ plus VPA have significant higher free fractions of CBZ and CBZ-E than do patients on CBZ alone, suggesting a protein-binding displacement by VPA. PMID:8665529

  12. Hypomineralized Second Primary Molars as Predictor of Molar Incisor Hypomineralization.

    PubMed

    Negre-Barber, A; Montiel-Company, J M; Boronat-Catalá, M; Catalá-Pizarro, M; Almerich-Silla, J M

    2016-01-01

    Molar incisor hypomineralization (MIH) is a developmental defect of dental enamel that shares features with hypomineralized second primary molars (HSPM). Prior to permanent tooth eruption, second primary molars could have predictive value for permanent molar and incisor hypomineralization. To assess this possible relationship, a cross-sectional study was conducted in a sample of 414 children aged 8 and 9 years from the INMA cohort in Valencia (Spain). A calibrated examiner (linear-weighted Kappa 0.83) performed the intraoral examinations at the University of Valencia between November 2013 and 2014, applying the diagnostic criteria for MIH and HSPM adopted by the European Academy of Paediatric Dentistry. 100 children (24.2%) presented MIH and 60 (14.5%) presented HSPM. Co-occurrence of the two defects was observed in 11.1% of the children examined. The positive predictive value was 76.7% (63.9-86.6) and the negative predictive value 84.7% (80.6-88.3). The positive likelihood ratio (S/1-E) was 10.3 (5.9-17.9) and the negative likelihood ratio (1-S/E) 0.57 (0.47-0.68). The odds ratio was 18.2 (9.39-35.48). It was concluded that while the presence of HSPM can be considered a predictor of MIH, indicating the need for monitoring and control, the absence of this defect in primary dentition does not rule out the appearance of MIH. PMID:27558479

  13. THERMAL AND SPECTROSCOPIC ANALYSES OF CAUSTIC SIDE SOLVENT EXTRACTION SOLVENT CONTACTED WITH 1 MOLARAND 3 MOLAR NITRIC ACID

    SciTech Connect

    Fondeur, F; David Hobbs, D; Samuel Fink, S

    2007-07-23

    Thermal and spectroscopic analyses were performed on multiple layers formed from contacting Caustic Side Solvent Extraction (CSSX) solvent with 1 M or 3 M nitric acid. A slow chemical reaction occurs (i.e., over several weeks) between the solvent and 1 M or 3 M nitric acid as evidenced by color changes and the detection of nitro groups in the infrared spectrum of the aged samples. Thermal analysis revealed that decomposition of the resulting mixture does not meet the definition of explosive or deflagrating material.

  14. Structures and standard molar enthalpies of formation of a series of Ln(III)–Cu(II) heteronuclear compounds with pyrazine-2,3-dicarboxylic acid

    SciTech Connect

    Yang, Qi; Xie, Gang; Wei, Qing; Chen, Sanping Gao, Shengli

    2014-07-01

    Fifteen lanthanide–copper heteronuclear compounds, formulated as [CuLn{sub 2}(pzdc){sub 4}(H{sub 2}O){sub 6}]·xH{sub 2}O (1–6(x=2), 8(x=3), 9–10(x=4)); [CuLn{sub 2}(pzdc){sub 4}(H{sub 2}O){sub 4}]·xH{sub 2}O (7, 12–13, 15(x=4), 14(x=5), 11(x=8)) (Ln(III)=La(1); Ce(2); Pr(3); Nd(4); Sm(5); Eu(6); Gd(7); Tb(8); Dy(9); Ho(10); Er(11); Tm(12); Yb(13); Lu(14); Y(15); H{sub 2}pzdc (C{sub 6}H{sub 4}N{sub 2}O{sub 4})=pyrazine-2,3-dicarboxylic acid) have been hydrothermally synthesized. All compounds were characterized by element analysis, IR spectroscopy, single-crystal X-ray diffraction and thermal analysis. X-ray diffraction analyses confirm that all compounds are isostructural and feature a 3D brick-like framework structure with (4.6{sup 2}){sub 2}(4{sup 2}.6{sup 2}.8{sup 2})(6{sup 3}){sup 2}(6{sup 5}.8){sub 2} topology. Using 1 mol cm{sup −3} HCl(aq) as calorimetric solvent, with an isoperibol solution–reaction calorimeter, the standard molar enthalpies of formation of all compounds were determined by a designed thermochemical cycle. In addition, solid state luminescence properties of compounds 5, 6, 8 and 9 were studied in the solid state. - Graphical abstract: According to Hess' rule, the standard molar enthalpies of formation of Ln–Cu heterometallic coordination compounds were determined by a designed thermochemical cycle. - Highlights: • Fifteen lanthanide–copper heteronuclear isostructural compounds. • Structurally characterization by IR, X-ray diffraction and thermal analysis. • The standard molar enthalpy of formation. • Isoperibol solution–reaction calorimetry.

  15. Effect of different processes and Ti/Zn molar ratios on the structure, morphology, and enhanced photoelectrochemical and photocatalytic performance of Ti3+ self-doped titanium-zinc hybrid oxides

    NASA Astrophysics Data System (ADS)

    Fu, Rongrong; Wang, Qingyao; Gao, Shanmin; Wang, Zeyan; Huang, Baibiao; Dai, Ying; Lu, Jun

    2015-07-01

    Ti3+ self-doped titanium-zinc hybrid oxides with different phase compositions and morphologies were successfully synthesized using Zn powder as the reductant and Zn source by a chemical-reduction precipitation method with subsequent thermal treatment. The fabricated Ti3+ self-doped TiO2(A)/TiO2(R), TiO2(A)/TiO2(R)/ZnTiO3, and TiO2(A)/ZnO heterojunctions were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and UV-Vis diffuse reflectance spectroscopy. The effects of various Ti/Zn molar ratios and preparation processes on the structural, morphological, optical, photocurrent and photocatalytic properties of the resultant samples were investigated systematically. Results reveal that Ti3+ self-doping enhances the photoabsorption capability of titanium-zinc hybrid oxides in the visible-light region. Moreover, different processes and Ti/Zn molar ratios play great influences on the structure, morphology, optical, photocurrent and photocatalytic properties of the final products. Ti3+ self-doped titanium-zinc hybrid oxides exhibit excellent photocurrent and photocatalytic activity than pure TiO2 and ZnTiO3 under visible-light irradiation (λ ≥ 400 nm). The most active Ti3+ self-doped titanium-zinc hybrid oxides photoanode presents significantly improved water splitting performance. The synergistic effect between the Ti3+ self-doped and heterojunctions is responsible for the enhanced performance of these materials.

  16. Effect of different processes and Ti/Zn molar ratios on the structure, morphology, and enhanced photoelectrochemical and photocatalytic performance of Ti3+ self-doped titanium–zinc hybrid oxides

    SciTech Connect

    Fu, Rongrong; Wang, Qingyao; Gao, shanmin; Wang, Zeyan; Huang, Baibiao; Dai, Ying; Lu, Jun

    2015-07-01

    Ti3+ self-doped titanium–zinc hybrid oxides with different phase compositions and morphologies were successfully synthesized using Zn powder as the reductant and Zn source by a chemical-reduction precipitation method with subsequent thermal treatment. The fabricated Ti3+ self-doped TiO2(A)/TiO2(R), TiO2(A)/TiO2(R)/ZnTiO3, and TiO2(A)/ZnO heterojunctions were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and UV–Vis diffuse reflectance spectroscopy. The effects of various Ti/Zn molar ratios and preparation processes on the structural, morphological, optical, photocurrent and photocatalytic properties of the resultant samples were investigated systematically. Results reveal that Ti3+ self-doping enhances the photoabsorption capability of titanium–zinc hybrid oxides in the visible-light region. Moreover, different processes and Ti/Zn molar ratios play great influences on the structure, morphology, optical, photocurrent and photocatalytic properties of the final products. Ti3+ self-doped titanium–zinc hybrid oxides exhibit excellent photocurrent and photocatalytic activity than pure TiO2 and ZnTiO3 under visible-light irradiation (λ ≥ 400 nm). The most active Ti3+ self-doped titanium–zinc hybrid oxides photoanode presents significantly improved water splitting performance. The synergistic effect between the Ti3+ self-doped and heterojunctions is responsible for the enhanced performance of these materials.

  17. Ratio

    NASA Astrophysics Data System (ADS)

    Webster, Nathan A. S.; Pownceby, Mark I.; Madsen, Ian C.; Studer, Andrew J.; Manuel, James R.; Kimpton, Justin A.

    2014-12-01

    Effects of basicity, B (CaO:SiO2 ratio) on the thermal range, concentration, and formation mechanisms of silico-ferrite of calcium and aluminum (SFCA) and SFCA-I iron ore sinter bonding phases have been investigated using an in situ synchrotron X-ray diffraction-based methodology with subsequent Rietveld refinement-based quantitative phase analysis. SFCA and SFCA-I phases are the key bonding materials in iron ore sinter, and improved understanding of the effects of processing parameters such as basicity on their formation and decomposition may assist in improving efficiency of industrial iron ore sintering operations. Increasing basicity significantly increased the thermal range of SFCA-I, from 1363 K to 1533 K (1090 °C to 1260 °C) for a mixture with B = 2.48, to ~1339 K to 1535 K (1066 °C to 1262 °C) for a mixture with B = 3.96, and to ~1323 K to 1593 K (1050 °C to 1320 °C) at B = 4.94. Increasing basicity also increased the amount of SFCA-I formed, from 18 wt pct for the mixture with B = 2.48 to 25 wt pct for the B = 4.94 mixture. Higher basicity of the starting sinter mixture will, therefore, increase the amount of SFCA-I, considered to be more desirable of the two phases. Basicity did not appear to significantly influence the formation mechanism of SFCA-I. It did, however, affect the formation mechanism of SFCA, with the decomposition of SFCA-I coinciding with the formation of a significant amount of additional SFCA in the B = 2.48 and 3.96 mixtures but only a minor amount in the highest basicity mixture. In situ neutron diffraction enabled characterization of the behavior of magnetite after melting of SFCA produced a magnetite plus melt phase assemblage.

  18. Effect of [Al] and [In] molar ratio in solutions on the growth and microstructure of electrodeposition Cu(In,Al)Se2 films

    NASA Astrophysics Data System (ADS)

    Huang, Kuo-Chan; Liu, Chien-Lin; Hung, Pin-Kun; Houng, Mau-Phon

    2013-05-01

    In this paper, the cyclic voltammetric studies were used to realize the element's reduction potential and chemical reaction mechanism for presuming the formation routes of quaternary Cu(In,Al)Se2 crystals. Thereafter, the prior adjustment of deposited potential from -0.6 V to -1.0 V can be identified a suitable potential as co-electrodeposition. The material characteristics of Cu(In,Al)Se2 films are dominated by the percentage of aluminum content. Thus, the influence of aluminum and indium concentrations in solutions on the percentage composition, surface morphology, structural and crystal properties, and optical energy band gap of Cu(In,Al)Se2 films were investigated. Energy dispersive X-ray spectroscopy (EDS) indicated that the ratio of Al to (Al + In) in Cu(In,Al)Se2 films varied from 0.21 to 0.42 when adjusting aluminum and indium concentrations in solutions. Scanning electron microscopy (SEM) shows that the surface morphology changed from round-like structures into cauliflower-like structures and became rough when the aluminum concentration increased and indium concentration decreased in solutions. X-ray diffraction (XRD) patterns revealed three preferred growth orientations along the (1 1 2), (2 0 4/2 2 0), and (1 1 6/3 1 2) planes for all species. The (αhυ)2 versus hυ plots (UV-Visible) shows that the optical energy band gap of the Cu(In,Al)Se2 films can be successfully controlled from 1.17 eV to 1.48 eV by adjusting the aluminum and indium concentrations. Furthermore, the shift of the (1 1 2) peak in the XRD patterns and variation of optical band gap are evidence that the incorporation of aluminum atoms into the crystallitic CuInSe2 forms Cu(In,Al)Se2 crystals.

  19. The effect of microbial sulfidogenesis on the stability of As-Fe coprecipitate with low Fe/As molar ratio under anaerobic conditions.

    PubMed

    Wang, Shaofeng; He, Xin Yu; Pan, Rongrong; Xu, Liying; Wang, Xin; Jia, Yongfeng

    2016-04-01

    The effect of microbial sulfidogenesis on As transformation and mobilization in solid phase with low Fe/As ratio is still not well known. In this study, microbial transformation and mobilization of As in the As-Fe coprecipitate with different sulfate levels were investigated using chemical extraction and K-edge XANES of As and S. Results showed that approximately 2.7, 24.4, and 83.7 % of total As were released into the aqueous phase in the low-, mid-, and high-sulfate treatments, respectively, indicating that the presence of large amounts of sulfate could enhance microbial arsenic mobilization in the As-Fe coprecipitate. In the low-sulfate treatment, As mobilization was primarily attributed to the reductive dissolution of the Fe (oxy)hydroxides and the As reduction and desorption. In the mid- and high-sulfate treatments, the reduction of arsenate and ferric iron was significantly enhanced. Complete ferric iron reduction was observed in the solid phase, implying that Fe (oxy)hydroxide was transformed to secondary minerals and may be the one of the primary causes for the enhanced As mobilization. Thermodynamic calculations predicted the formation of thioarsenite species after 35 days of incubation based on the concentration of dissolved As(III) and S(-II). Since thioarsenic species is more mobile, its formation may be one of the most important factors enhancing the As release in the high-sulfate system. The result of this study is of significance to completely predict the environmental behavior of As associated with Fe (hydr)oxides in the presence of microbial sulfidogenesis under anoxic conditions. PMID:26676545

  20. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity.

    PubMed

    Simopoulos, Artemis P

    2016-01-01

    In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation. Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC) membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity. Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity. PMID:26950145

  1. An Increase in the Omega-6/Omega-3 Fatty Acid Ratio Increases the Risk for Obesity

    PubMed Central

    Simopoulos, Artemis P.

    2016-01-01

    In the past three decades, total fat and saturated fat intake as a percentage of total calories has continuously decreased in Western diets, while the intake of omega-6 fatty acid increased and the omega-3 fatty acid decreased, resulting in a large increase in the omega-6/omega-3 ratio from 1:1 during evolution to 20:1 today or even higher. This change in the composition of fatty acids parallels a significant increase in the prevalence of overweight and obesity. Experimental studies have suggested that omega-6 and omega-3 fatty acids elicit divergent effects on body fat gain through mechanisms of adipogenesis, browning of adipose tissue, lipid homeostasis, brain-gut-adipose tissue axis, and most importantly systemic inflammation. Prospective studies clearly show an increase in the risk of obesity as the level of omega-6 fatty acids and the omega-6/omega-3 ratio increase in red blood cell (RBC) membrane phospholipids, whereas high omega-3 RBC membrane phospholipids decrease the risk of obesity. Recent studies in humans show that in addition to absolute amounts of omega-6 and omega-3 fatty acid intake, the omega-6/omega-3 ratio plays an important role in increasing the development of obesity via both AA eicosanoid metabolites and hyperactivity of the cannabinoid system, which can be reversed with increased intake of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). A balanced omega-6/omega-3 ratio is important for health and in the prevention and management of obesity. PMID:26950145

  2. Detection of exogenous citric acid in fruit juices by stable isotope ratio analysis.

    PubMed

    Jamin, Eric; Martin, Frédérique; Santamaria-Fernandez, Rebeca; Lees, Michèle

    2005-06-29

    A new method has been developed for measuring the D/H ratio of the nonexchangeable sites of citric acid by isotope ratio mass spectrometry (IRMS). Pure citric acid is transformed into its calcium salt and subsequently analyzed by pyrolysis-IRMS. The citric acid isolated from authentic fruit juices (citrus, pineapple, and red fruits) systematically shows higher D/H values than its nonfruit counterpart produced by fermentation of various sugar sources. The discrimination obtained with this simplified method is similar to that obtained previously by applying site specific isotopic fractionation-nuclear magnetic resonance (SNIF-NMR) to an ester derivative of citric acid. The combination of carbon 13 and deuterium measurements of extracted citric acid is proposed as a routine method for an optimum detection of exogenous citric acid in all kinds of fruit juices. PMID:15969486

  3. Partial molar volumes and viscosities of aqueous hippuric acid solutions containing LiCl and MnCl2 · 4H2O at 303.15 K

    NASA Astrophysics Data System (ADS)

    Deosarkar, S. D.; Tawde, P. D.; Zinjade, A. B.; Shaikh, A. I.

    2015-09-01

    Density (ρ) and viscosity (η) of aqueous hippuric acid (HA) solutions containing LiCl and MnCl2 · 4H2O have been studied at 303.15 K in order to understand volumetric and viscometric behavior of these systems. Apparent molar volume (φv) of salts were calculated from density data and fitted to Massons relation and partial molar volumes (φ{v/0}) at infinite dilution were determined. Relative viscosity data has been used to determine viscosity A and B coefficients using Jones-Dole relation. Partial molar volume and viscosity coefficients have been discussed in terms of ion-solvent interactions and overall structural fittings in solution.

  4. Carbon Isotopic Ratios of Amino Acids in Stardust-Returned Samples

    NASA Technical Reports Server (NTRS)

    Elsila, Jamie E.; Glavin, Daniel P.; Dworkin, Jason P.

    2009-01-01

    NASA's Stardust spacecraft returned to Earth samples from comet 81P/Wild 2 in January 2006. Preliminary examinations revealed the presence of a suite of organic compounds including several amines and amino acids, but the origin of these compounds could not be identified. Here. we present the carbon isotopic ratios of glycine and E-aminocaproic acid (EACH), the two most abundant amino acids observed, in Stardust-returned foil samples measured by gas chromatography-combustion-isotope ratio crass spectrometry coupled with quadrupole mass spectrometry (GC-QMS/IRMS).

  5. Evaluation of serum sialic acid, fucose levels and their ratio in oral squamous cell carcinoma

    PubMed Central

    Chinnannavar, Sangamesh Ningappa; Ashok, Lingappa; Vidya, Kodige Chandrashekhar; Setty, Sunil Mysore Kantharaja; Narasimha, Guru Eraiah; Garg, Ranjana

    2015-01-01

    Background: Detection of cancer at the early stage is of utmost importance to decrease the morbidity and mortality of the disease. Apart from the conventional biopsy, minimally invasive methods like serum evaluation are used for screening large populations. Thus, this study aimed to estimate serum levels of sialic acid and fucose and their ratio in oral cancer patients and in healthy control group to evaluate their role in diagnosis. Materials and Methods: Serum samples were collected from 52 healthy controls (group I) and 52 squamous cell carcinoma patients (group II). Estimation of serum levels of sialic acid and fucose and their ratio was performed. This was correlated histopathologically with the grades of carcinoma. Statistical analysis was done by using analysis of variance (ANOVA) test and unpaired “t” test. Results: Results showed that serum levels of sialic acid and fucose were significantly higher in oral cancer patients compared to normal healthy controls (P < 0.001). The sialic acid to fucose ratio was significantly lower in cancer patients than in normal controls (P < 0.01). However, comparison with histological grading, habits, gender, and age group did not show any significant result. Conclusion: The mean serum sialic acid and fucose levels showed an increasing trend from controls to malignant group and their corresponding ratio showed decreasing trend from controls to malignant group. The ratio of sialic acid to fucose can be a useful diagnostic aid for oral cancer patients. PMID:26759796

  6. Structures and standard molar enthalpies of formation of a series of Ln(III)-Cu(II) heteronuclear compounds with pyrazine-2,3-dicarboxylic acid

    NASA Astrophysics Data System (ADS)

    Yang, Qi; Xie, Gang; Wei, Qing; Chen, Sanping; Gao, Shengli

    2014-07-01

    Fifteen lanthanide-copper heteronuclear compounds, formulated as [CuLn2(pzdc)4(H2O)6]·xH2O (1-6(x=2), 8(x=3), 9-10(x=4); [CuLn2(pzdc)4(H2O)4]·xH2O (7, 12-13, 15(x=4), 14(x=5), 11(x=8) (Ln(III)=La(1); Ce(2); Pr(3); Nd(4); Sm(5); Eu(6); Gd(7); Tb(8); Dy(9); Ho(10); Er(11); Tm(12); Yb(13); Lu(14); Y(15); H2pzdc (C6H4N2O4)=pyrazine-2,3-dicarboxylic acid) have been hydrothermally synthesized. All compounds were characterized by element analysis, IR spectroscopy, single-crystal X-ray diffraction and thermal analysis. X-ray diffraction analyses confirm that all compounds are isostructural and feature a 3D brick-like framework structure with {4.62}2{42.62.82}{63}2{65.8}2 topology. Using 1 mol cm-3 HCl(aq) as calorimetric solvent, with an isoperibol solution-reaction calorimeter, the standard molar enthalpies of formation of all compounds were determined by a designed thermochemical cycle. In addition, solid state luminescence properties of compounds 5, 6, 8 and 9 were studied in the solid state.

  7. Reduction in Dietary Omega-6 Polyunsaturated Fatty Acids: Eicosapentaenoic Acid plus Docosahexaenoic Acid Ratio Minimizes Atherosclerotic Lesion Formation and Inflammatory Response in the LDL Receptor Null Mouse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dietary very long chain omega-3 polyunsaturated fatty acids (PUFA) have been associated with reduced CVD risk. LDL receptor null mice (LDLr-/-) were used to assess different dietary ratios of omega-6 PUFA to eicosapentaenoic acid plus docosahexaenoic acid (omega-6:EPA+DHA) on atherogenesis and infl...

  8. The importance of the ratio of omega-6/omega-3 essential fatty acids.

    PubMed

    Simopoulos, A P

    2002-10-01

    Several sources of information suggest that human beings evolved on a diet with a ratio of omega-6 to omega-3 essential fatty acids (EFA) of approximately 1 whereas in Western diets the ratio is 15/1-16.7/1. Western diets are deficient in omega-3 fatty acids, and have excessive amounts of omega-6 fatty acids compared with the diet on which human beings evolved and their genetic patterns were established. Excessive amounts of omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-6/omega-3 ratio, as is found in today's Western diets, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a low omega-6/omega-3 ratio) exert suppressive effects. In the secondary prevention of cardiovascular disease, a ratio of 4/1 was associated with a 70% decrease in total mortality. A ratio of 2.5/1 reduced rectal cell proliferation in patients with colorectal cancer, whereas a ratio of 4/1 with the same amount of omega-3 PUFA had no effect. The lower omega-6/omega-3 ratio in women with breast cancer was associated with decreased risk. A ratio of 2-3/1 suppressed inflammation in patients with rheumatoid arthritis, and a ratio of 5/1 had a beneficial effect on patients with asthma, whereas a ratio of 10/1 had adverse consequences. These studies indicate that the optimal ratio may vary with the disease under consideration. This is consistent with the fact that chronic diseases are multigenic and multifactorial. Therefore, it is quite possible that the therapeutic dose of omega-3 fatty acids will depend on the degree of severity of disease resulting from the genetic predisposition. A lower ratio of omega-6/omega-3 fatty acids is more desirable in reducing the risk of many of the chronic diseases of high prevalence in Western societies, as well as in the developing countries, that are being exported to the rest of the world. PMID:12442909

  9. Hypomineralized Second Primary Molars as Predictor of Molar Incisor Hypomineralization

    PubMed Central

    Negre-Barber, A.; Montiel-Company, J. M.; Boronat-Catalá, M.; Catalá-Pizarro, M.; Almerich-Silla, J. M.

    2016-01-01

    Molar incisor hypomineralization (MIH) is a developmental defect of dental enamel that shares features with hypomineralized second primary molars (HSPM). Prior to permanent tooth eruption, second primary molars could have predictive value for permanent molar and incisor hypomineralization. To assess this possible relationship, a cross-sectional study was conducted in a sample of 414 children aged 8 and 9 years from the INMA cohort in Valencia (Spain). A calibrated examiner (linear-weighted Kappa 0.83) performed the intraoral examinations at the University of Valencia between November 2013 and 2014, applying the diagnostic criteria for MIH and HSPM adopted by the European Academy of Paediatric Dentistry. 100 children (24.2%) presented MIH and 60 (14.5%) presented HSPM. Co-occurrence of the two defects was observed in 11.1% of the children examined. The positive predictive value was 76.7% (63.9–86.6) and the negative predictive value 84.7% (80.6–88.3). The positive likelihood ratio (S/1-E) was 10.3 (5.9–17.9) and the negative likelihood ratio (1-S/E) 0.57 (0.47–0.68). The odds ratio was 18.2 (9.39–35.48). It was concluded that while the presence of HSPM can be considered a predictor of MIH, indicating the need for monitoring and control, the absence of this defect in primary dentition does not rule out the appearance of MIH. PMID:27558479

  10. LC/ESI-MS/MS method for determination of salivary eicosapentaenoic acid concentration to arachidonic acid concentration ratio.

    PubMed

    Ogawa, Shoujiro; Tomaru, Koki; Matsumoto, Nagisa; Watanabe, Shui; Higashi, Tatsuya

    2016-01-01

    A simple liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) method for determination of the eicosapentaenoic acid (EPA) concentration to arachidonic acid (AA) concentration ratio in human saliva has been developed. The EPA/AA ratio in serum or plasma is widely recognized as a useful indicator in identifying the risk of cardiovascular disease, especially atherosclerosis. The salivary EPA/AA ratio is expected to be a convenient alternative to the serum or plasma EPA/AA ratio, because saliva offers the advantages of easy and noninvasive sampling. The saliva was deproteinized with acetonitrile, purified using an Oasis HLB cartridge, and derivatized with 1-[(4-dimethylaminophenyl)carbonyl]piperazine (DAPPZ). The derivatized EPA and AA were subjected to LC/ESI-MS/MS, and the EPA/AA ratio was determined using the selected reaction monitoring mode. The DAPPZ-derivatization increased the ESI sensitivity by 100- and 300-fold for EPA and AA, respectively, and enabled the detection of trace fatty acids in saliva using a 200 μL sample. The assay reproducibility was satisfactory (relative standard deviation, <5.0%). The method was successfully applied to the measurement of the salivary EPA/AA ratios of healthy Japanese subjects and their changes owing to the supplementation of EPA. PMID:25620210

  11. Arachidonic acid enhances reproduction in Daphnia magna and mitigates changes in sex ratios induced by pyriproxyfen.

    PubMed

    Ginjupalli, Gautam K; Gerard, Patrick D; Baldwin, William S

    2015-03-01

    Arachidonic acid is 1 of only 2 unsaturated fatty acids retained in the ovaries of crustaceans and an inhibitor of HR97g, a nuclear receptor expressed in adult ovaries. The authors hypothesized that, as a key fatty acid, arachidonic acid may be associated with reproduction and potentially environmental sex determination in Daphnia. Reproduction assays with arachidonic acid indicate that it alters female:male sex ratios by increasing female production. This reproductive effect only occurred during a restricted Pseudokirchneriella subcapitata diet. Next, the authors tested whether enriching a poorer algal diet (Chlorella vulgaris) with arachidonic acid enhances overall reproduction and sex ratios. Arachidonic acid enrichment of a C. vulgaris diet also enhances fecundity at 1.0 µM and 4.0 µM by 30% to 40% in the presence and absence of pyriproxyfen. This indicates that arachidonic acid is crucial in reproduction regardless of environmental sex determination. Furthermore, the data indicate that P. subcapitata may provide a threshold concentration of arachidonic acid needed for reproduction. Diet-switch experiments from P. subcapitata to C. vulgaris mitigate some, but not all, of arachidonic acid's effects when compared with a C. vulgaris-only diet, suggesting that some arachidonic acid provided by P. subcapitata is retained. In summary, arachidonic acid supplementation increases reproduction and represses pyriproxyfen-induced environmental sex determination in D. magna in restricted diets. A diet rich in arachidonic acid may provide protection from some reproductive toxicants such as the juvenile hormone agonist pyriproxyfen. Environ Toxicol Chem 2015;34:527-535. © 2014 SETAC. PMID:25393616

  12. Investigation on properties of Pd/CeO2-ZrO2-Pr2O3 catalysts with different Ce/Zr molar ratios and its application for automotive emission control.

    PubMed

    Yang, Xue; Yang, Linyan; Lin, Siyu; Zhou, Renxian

    2015-03-21

    Pd/CeO2-ZrO2-Pr2O3 (CZP) catalysts with different Ce/Zr molar ratios were synthesized and systematically investigated by XRD, N2 adsorption-desorption, XPS, H2-TPR, OSC and in situ DRIFTS techniques. The results of XPS, in situ DRIFTS, etc., show that the number of oxygen vacancies increases with the increasing Zr content and thus leads to the enhanced metal-support interaction and the accelerative formation rate of nitrate, formate, acetate and carbonate species, resulting in improving catalytic performance for HC and NO elimination, especially for Pd/CZP catalysts with Ce/Zr from 1/2 to 1/3. While Pd/CZP catalysts with higher OSC value (Ce/Zr=4/1-1/2) exhibit better catalytic activity of CO and NO2 elimination. An appropriate concentration of Zr facilitates the diffusion of Pr from the surface to the bulk of the CZP supports, thus forming more homogeneous CZP solid solution and improving the structure/textual stability, which promotes the thermal stability of catalysts. Pd/CZP catalysts with Ce/Zr from 2/1 to 1/2 exhibit good thermal stability. PMID:25497032

  13. Analysis of mercury and methylmercury concentrations, and selenium:mercury molar ratios for a toxicological assessment of sperm whales (Physeter macrocephalus) in the most recent stranding event along the Adriatic coast (Southern Italy, Mediterranean Sea).

    PubMed

    Squadrone, S; Chiaravalle, E; Gavinelli, S; Monaco, G; Rizzi, M; Abete, M C

    2015-11-01

    Mass stranding of sperm whales (Physeter macrocephalus) is a rare event in the Mediterranean Sea. In September 2014, a pod of seven sperm whales became stranded along the Adriatic coast of Southern Italy. This is the seventh occurrence of this type since 1555 in this sea basin. Total concentrations of mercury (T-Hg), methylmercury (MeHg) and selenium (Se) were measured from brain, muscle, liver and kidney of three female sperm whales, which died in this event. Analyses showed considerable, age-dependent variations in Hg and Se concentrations in the different organs. The contamination levels of T-Hg in the liver (up to 200 mg kg(-1)) and brain (up to 21 mg kg(-1)) samples were markedly higher than those in the kidney and muscle samples. The liver and brain also showed the highest Se levels. Se:Hg molar ratios ⩾1 were observed in all the organs of the three sperm whales, suggesting that Se could protect the animals from Hg toxicity. The risk of Hg-associated neurotoxicity was assessed by comparing our values to thresholds set for neurotoxicity in mammals, and the role of Se in the detoxification process of T-Hg/MeHg is discussed herein. PMID:26233668

  14. Direct determination of the NaF/AlF3 molar ratio by Raman spectroscopy in NaF-AlF3-CaF2 melts at 1000 °C.

    PubMed

    Malherbe, Cedric; Gilbert, Bernard

    2013-09-17

    For the last 40 years, Raman spectroscopy has been very useful in investigating the structure of corrosive molten salts, such as the cryolite-based melts widely used as electrolyte in the Hall-Heroult process. Even if this process remains the most economically efficient for metallic aluminum electro-production, it suffers from a high energy loss, which is dependent on the melt composition. Therefore, controlling the chemical composition of the electrolyte is essential. The present paper proposes to apply Raman spectroscopy for the direct determination of the NaF-AlF3 molar ratio in NaF-AlF3-CaF2-based melts. Despite the experimental difficulties, a calibration curve based on equilibria taking place in the melt has been developed and the procedure has been successfully compared to industrial samples of known compositions. The possible exportation of the laboratory scale procedure to an industrial environment application for the control of the Hall-Heroult process is finally discussed. PMID:23988269

  15. USE OF FATTY ACID STABLE CARBON ISOTOPE RATIO TO INDICATE MICROBIAL CARBON SOURCE IN TROPICAL SOILS

    EPA Science Inventory


    We use measurements of the concentration and stable carbon isotope ratio of individual microbial phospholipid fatty acids (PLFAs) in soils as indicators of live microbial biomass levels, broad microbial community structure, and microbial carbon source. For studies of soil o...

  16. USE OF THE COMPOSITION AND STABLE CARBONIISOTOPE RATIO OF MICROBIAL FATTY ACIDS TO STUDY CARBON CYCLING

    EPA Science Inventory

    We use measurements of the concentration and stable carbon isotopic ratio (*13C) of individual microbial phospholipid fatty acids (PLFAs) in soils and sediments as indicators of live microbial biomass levels and microbial carbon source. For studies of soil organic matter (SOM) cy...

  17. Structure of aldobiouronic acid and glucuronic acid from Agathis australis degraded gum polysaccharide.

    PubMed

    Singh, R B

    2007-04-01

    Agathis australis gum on acid hydrolysis with sulphuric acid yielded L-arabinose and D-galactose in 1:4 molar ratio with traces of L-fucose. The components of aldobiouronic acid and glucuronic acid were obtained by graded hydrolysis of degraded gum polysaccharide. The derivatives of aldobiouronic acid was obtained as methyl ester methyl glycoside. PMID:17915743

  18. Omega-6 to Omega-3 Fatty Acid Ratio in Patients with ADHD: A Meta-Analysis

    PubMed Central

    LaChance, Laura; McKenzie, Kwame; Taylor, Valerie H.; Vigod, Simone N.

    2016-01-01

    Objective: Omega-3 and omega-6 fatty acids have been shown to be deficient in individuals with attention deficit/hyperactivity disorder compared to controls (Hawkey & Nigg, 2014). Clinical trials of omega-3 and omega-6 supplements as treatment for ADHD have demonstrated minimal efficacy (Bloch & Qawasmi, 2011; Gillies, Sinn, Lad, Leach, & Ross, 2011; Hawkey & Nigg, 2014; Puri & Martins, 2014; Sonuga-Barke et al., 2013). Existing trials have analyzed omega-3 and omega-6 separately although the tissue ratio of these fatty acids (n6/n3) may be more important than absolute levels of either. The objective of this study was to determine the relationship between blood n6/n3 and arachidonic acid to eicosapentaenoic acid (AA/EPA), to ADHD symptoms. Method: A systematic literature review identified original articles measuring blood n6/n3 or AA/EPA ratio in children and youth with ADHD, compared to controls without ADHD. Three databases were searched. Blood n6/n3, and AA/EPA ratios were compared between individuals with ADHD and controls. Results were pooled across studies using quantitative synthesis. Results: Five articles met inclusion criteria for the meta-analysis. The pooled mean difference between patients with ADHD and controls was 1.97 (0.90–3.04) for n6/n3 (n=5 studies, I2 83%) and 8.25 (5.94–10.56) for AA/EPA (n=3 studies, I2 0%). Conclusions: Children and youth with ADHD have elevated ratios of both blood n6/n3 and AA/EPA fatty acids compared to controls. Thus an elevated n6/n3, and more specifically AA/EPA, ratio may represent the underlying disturbance in essential fatty acid levels in patients with ADHD. These findings have implications for the development of future interventions using essential fatty acids to treat ADHD, and for the use of these ratios as biomarkers for titrating and monitoring ADHD treatment with essential fatty acids. PMID:27274744

  19. Eicosapentaenoic acid/docosahexaenoic acid 1:1 ratio improves histological alterations in obese rats with metabolic syndrome

    PubMed Central

    2014-01-01

    Background Marine polyunsaturated fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) have been associated with improvement in the Metabolic Syndrome (MS). The aim of this study is to evaluate how three fish-oil diets with different eicosapentaenoic acid/docosahexaenoic acid ratios (EPA/DHA ratio) affect the histology of liver, kidney, adipose tissue and aorta in a preliminary morphological study. This work uses an animal model of metabolic syndrome in comparison with healthy animals in order to provide information about the best EPA:DHA ratio to prevent or to improve metabolic syndrome symptoms. Methods 35 Wistar rats, as a control, and 35 spontaneously hypertensive obese rats (SHROB) were fed for 13 weeks with 3 different suplemmentation of fish oil containing EPA and DHA ratios (1:1, 2:1 and 1:2, respectively). All samples were stained with haematoxylin/eosin stain, except aorta samples, which were stained also with Verhoeff and van Gieson’s stain. A histological study was carried out to evaluate changes. These changes were statistically analyzed using SPSS IBM 19 software. The quantitative data were expressed by mean ± SD and were compared among groups and treatments using ANOVA with post-hoc tests for parametric data and the U-Mann–Whitney for non-parametric data. Qualitative data were expressed in frequencies, and compared with contingency tables using χ2 statistics. Results EPA:DHA 1:1 treatment tended to improve the density and the wrinkling of elastic layers in SHROB rats. Only Wistar rats fed with EPA:DHA 1:1 treatment did not show mast cells in adipose tissue and has less kidney atrophy. In both strains EPA:DHA 1:1 treatment improved inflammation related parameters in liver and kidney. Conclusions EPA:DHA 1:1 treatment was the most beneficial treatment since improved many histological parameters in both groups of rats. PMID:24512213

  20. Ruptured tubal molar pregnancy.

    PubMed

    Yakasai, I A; Adamu, N; Galadanchi, H S

    2012-01-01

    Molar pregnancies in most instances develop within the uterine cavity, but may occur at any site. Ectopic molar pregnancy is a rare event. The objective of this study was to present a case of ruptured tubal molar gestation, discuss its clinical features and ways to improve diagnostic accuracy. A 35-year-old woman presented with features suggestive of ruptured tubal ectopic pregnancy. There was neither any evidence at the time of presentation to suspect a molar gestation, nor β human chorionic gonadotrophin (βhCG) hormone estimation was done, but only a clearview pregnancy test was carried out. She had total left salpingectomy and histological evaluation of the specimen revealed complete hydatidiform mole. The hCG level normalized within 3 weeks of follow-up. Clinical features of ectopic molar pregnancy may be indistinguishable from non-molar ectopic pregnancy. We recommend βhCG estimation as well as histological examination of the surgical specimen for all patients coming with features suggestive of ectopic pregnancy. PMID:23238205

  1. Anger induced by interferon-alpha is moderated by ratio of arachidonic acid to omega-3 fatty acids

    PubMed Central

    Lotrich, Francis E.; Sears, Barry; McNamara, Robert K.

    2013-01-01

    Objective Anger worsens in some patients during interferon-alpha (IFN-α) therapy. Elevated anger has also been associated with lower long-chain omega-3 (LCn-3) fatty acid levels. We examined whether fatty acids could influence vulnerability to anger during IFN-α exposure. Methods Plasma arachidonic acid (AA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) levels were determined prior to IFN-α therapy by mass spectroscopy. Repeated-measure analyses examined the relationship between AA/EPA+DHA and the subsequent development of labile anger and irritability in 82 subjects who prospectively completed the Anger, Irritability, and Assault Questionnaire (AIAQ) during the first eight weeks of IFN-α therapy. Results Prior to IFN-α therapy, AA/EPA+DHA did not correlate with either labile anger or irritability. Pre-treatment AA/EPA+DHA did correlate with the subsequent maximal increase in labile anger during IFN-α therapy (r=0.33; p=0.005). Over time, labile anger increased more in subjects with above median AA/EPA+DHA ratios (p<0.05). Of the 17 subjects ultimately requiring psychiatric intervention for anger, 14/17 had above-median AA/EPA+DHA ratios (p=0.009). There was also an interaction with the tumor necrosis factor-alpha (TNF-α) promoter polymorphism (A-308G), such that only those with both elevated AA/EPA+DHA and the A allele had increased labile anger (p=0.001). In an additional 18 subjects, we conversely observed that selective serotonin reuptake inhibitor treatment was associated with increased irritability during IFN-α therapy. Conclusion LCn-3 fatty acid status may influence anger development during exposure to elevated inflammatory cytokines, and may interact with genetic risk for increased brain TNF-α. LCn-3 supplements may be one strategy for minimizing this adverse side effect of IFN-α. PMID:24182638

  2. The Urinary Uric Acid/Creatinine Ratio is An Adjuvant Marker for Perinatal Asphyxia

    PubMed Central

    Bhongir, Aparna Varma; Yakama, Akhil Varma Venkata; Saha, Subhajit; Radia, Sejal B.; Pabbati, Jayalakshmi

    2015-01-01

    Objective To assess the urinary uric acid/creatinine ratio (UA/Cr) in relation to Apgar score and cord blood gas analysis in identification of perinatal asphyxia and to define the cutoff values. Design case control study. Setting The newborns admitted in the department of pediatrics and NICU of Mediciti Institute of Medical Science, Ghanpur, Medchal mandal, Telangana from May-July 2011 were enrolled. Participants/patients The study was conducted on 31 (18 males, 13 females) controls and 18 (12males, 6 females) asphyxiated neonates. Outcome Measure(s) 5ml of arterial cord blood of newborn collected at the time of birth and spot urine samples were collected within 24-72 hours of life. Cord blood gas analysis were done immediately and Urinary uric acid was measured by modified Uricase method, urinary creatinine by modified kinetic Jaffe's reaction. Results The mean urinary uric acid and creatinine ratio (2.58± 0.48 vs 1.89 ± 0.59) is significantly higher in Asphyxiated group than in the control group. The umbilical cord blood pH had significant positive correlation with 1st minute Apgar score (r= 0.41, p=0.003), 5th minute Apgar (r= 0.44, p=0.002), while urinary UA/Cr ratio had significant negative correlation with cord blood pH (r= -0.63, p=0.002). Urinary UA/Cr ratio with criterion of >2.43 had 80% sensitivity, 87.5% specificity with AUC of 0.84 (p=0.003) had a better predictive value. Conclusions Urinary UA/Cr ratio is easy, non-invasive, painless and economical adjuvant parameter with better predictive value for diagnosing perinatal asphyxia with simple diagnostic equipment. PMID:26998526

  3. RNA:DNA Ratio and Other Nucleic Acid Derived Indices in Marine Ecology

    PubMed Central

    Chícharo, Maria Alexandra; Chícharo, Luis

    2008-01-01

    Some of most used indicators in marine ecology are nucleic acid-derived indices. They can be divided by target levels in three groups: 1) at the organism level as ecophysiologic indicators, indicators such as RNA:DNA ratios, DNA:dry weight and RNA:protein, 2) at the population level, indicators such as growth rate, starvation incidence or fisheries impact indicators, and 3) at the community level, indicators such as trophic interactions, exergy indices and prey identification. The nucleic acids derived indices, especially RNA:DNA ratio, have been applied with success as indicators of nutritional condition, well been and growth in marine organisms. They are also useful as indicators of natural or anthropogenic impacts in marine population and communities, such as upwelling or dredge fisheries, respectively. They can help in understanding important issues of marine ecology such as trophic interactions in marine environment, fish and invertebrate recruitment failure and biodiversity changes, without laborious work of counting, measuring and identification of small marine organisms. Besides the objective of integrate nucleic acid derived indices across levels of organization, the paper will also include a general characterization of most used nucleic acid derived indices in marine ecology and also advantages and limitations of them. We can conclude that using indicators, such RNA:DNA ratios and other nucleic acids derived indices concomitantly with organism and ecosystems measures of responses to climate change (distribution, abundance, activity, metabolic rate, survival) will allow for the development of more rigorous and realistic predictions of the effects of anthropogenic climate change on marine systems. PMID:19325815

  4. The ratio of unsaturated fatty acids in biosurfactants affects the efficiency of gene transfection.

    PubMed

    Inoh, Yoshikazu; Furuno, Tadahide; Hirashima, Naohide; Kitamoto, Dai; Nakanishi, Mamoru

    2010-10-15

    An unsaturated hydrocarbon chain in phospholipid was reported to affect a phase transition and a fusogenic activity after mixing membranes, and consequently to achieve a high DNA transfection efficiency. We previously showed that a biosurfactant mannosylerythritol lipid-A (MEL-A) enhances the gene transfection efficiency of cationic liposomes. Here, we have studied the effects of unsaturated fatty acid ratio of MEL-A on the physicochemical properties and gene delivery into cells of cationic liposomes using MEL-A with three different unsaturated fatty acid ratios (9.1%, 21.5%, and 46.3%). The gene transfer efficiency of cationic liposomes containing MEL-A (21.5%) was much higher than that of those containing MEL-A (9.1%) and MEL-A (46.3%). MEL-A (21.5%)-containing cationic liposomes induced highly efficient membrane fusion after addition of anionic liposomes and led to subsequent DNA release. Imaging analysis revealed that MEL-A (21.5%)-containing liposomes fused with the plasma membrane and delivered DNA into the nucleus of NIH-3T3 cells, MEL-A (46.3%)-containing liposomes fused with the plasma membrane did not deliver DNA into the nucleus, and MEL-A (9.1%)-containing liposomes neither fused with the plasma membrane nor delivered DNA into the nucleus. Thus, it is understandable that the unsaturated fatty acid ratio of MEL-A strongly influences the gene transfection efficiency of cationic liposomes. PMID:20674726

  5. ANALYSIS OF RICIN TOXIN PREPARATIONS FOR CARBOHYDRATE AND FATTY ACID ABUNDANCE AND ISOTOPE RATIO INFORMATION

    SciTech Connect

    Wunschel, David S.; Kreuzer-Martin, Helen W.; Antolick, Kathryn C.; Colburn, Heather A.; Moran, James J.; Melville, Angela M.

    2009-12-01

    employing a quadrupole MS system for compound identification and an isotope ratio MS for measuring the stable isotope ratios of deuterium and hydrogen (D/H) in fatty acids. Finally, the method for analyzing the compound abundance data is included. This study indicates that removal of ricinoleic acid is a conserved consequence of each processing step we tested. Furthermore, the stable isotope D/H ratio of ricinoleic acid distinguished between two of the three castor seed sources. Concentrations of arabinose, xylose, mannose, glucosamine and myo-inositol differentiated between crude or acetone extracted samples and samples produced by protein precipitation. Taken together these data illustrate the ability to distinguish between processes used to purify a ricin sample as well as potentially the source seeds.

  6. Molars and incisors: show your microarray IDs

    PubMed Central

    2013-01-01

    Background One of the key questions in developmental biology is how, from a relatively small number of conserved signaling pathways, is it possible to generate organs displaying a wide range of shapes, tissue organization, and function. The dentition and its distinct specific tooth types represent a valuable system to address the issues of differential molecular signatures. To identify such signatures, we performed a comparative transcriptomic analysis of developing murine lower incisors, mandibular molars and maxillary molars at the developmental cap stage (E14.5). Results 231 genes were identified as being differentially expressed between mandibular incisors and molars, with a fold change higher than 2 and a false discovery rate lower than 0.1, whereas only 96 genes were discovered as being differentially expressed between mandibular and maxillary molars. Numerous genes belonging to specific signaling pathways (the Hedgehog, Notch, Wnt, FGF, TGFβ/BMP, and retinoic acid pathways), and/or to the homeobox gene superfamily, were also uncovered when a less stringent fold change threshold was used. Differential expressions for 10 out of 12 (mandibular incisors versus molars) and 9 out of 10 selected genes were confirmed by quantitative reverse transcription-PCR (qRT-PCR). A bioinformatics tool (Ingenuity Pathway Analysis) used to analyze biological functions and pathways on the group of incisor versus molar differentially expressed genes revealed that 143 genes belonged to 9 networks with intermolecular connections. Networks with the highest significance scores were centered on the TNF/NFκB complex and the ERK1/2 kinases. Two networks ERK1/2 kinases and tretinoin were involved in differential molar morphogenesis. Conclusion These data allowed us to build several regulatory networks that may distinguish incisor versus molar identity, and may be useful for further investigations of these tooth-specific ontogenetic programs. These programs may be dysregulated in

  7. Arachidonic Acid Enhances Reproduction in Daphnia magna and Mitigates Changes in Sex Ratios Induced by Pyriproxyfen

    PubMed Central

    Ginjupalli, Gautam K.; Gerard, Patrick D.; Baldwin, William S.

    2016-01-01

    Arachidonic acid (AA) is one of only two unsaturated fatty acids retained in the ovaries of crustaceans, and an inhibitor of HR97g, a nuclear receptor expressed in adult ovaries. We hypothesized that as a key fatty acid, AA may be associated with reproduction and potentially environmental sex determination in Daphnia. Reproduction assays with AA indicate that it alters female/male sex ratios by increasing female production. This reproductive effect only occurred during a restricted P. subcapitata diet. Next, we tested whether enriching a poorer algal diet (C. vulgaris) with AA enhances overall reproduction and sex ratios. AA enrichment of a C. vulgaris diet also enhances fecundity at 1.0 and 4.0μM by 30–40% in the presence and absence of pyriproxyfen. This indicates that AA is crucial in reproduction regardless of environmental sex determination. Furthermore, our data indicates that P. subcapitata may provide a threshold concentration of AA needed for reproduction. Diet switch experiments from P. subcapitata to C. vulgaris mitigate some but not all of AA’s effects when compared to a C. vulgaris only diet, suggesting that some AA provided by P. subcapitata is retained. In summary, AA supplementation increases reproduction and represses pyriproxyfen-induced environmental sex determination in D. magna in restricted diets. A diet rich in AA may provide protection from some reproductive toxicants such as the juvenile hormone agonist, pyriproxyfen. PMID:25393616

  8. The effect of zeolite treatment by acids on sodium adsorption ratio of coal seam gas water.

    PubMed

    Wang, Xiaoyu; Ozdemir, Orhan; Hampton, Marc A; Nguyen, Anh V; Do, Duong D

    2012-10-15

    Many coal seam gas (CSG) waters contain a sodium ion concentration which is too high relative to calcium and magnesium ions for environment acceptance. Natural zeolites can be used as a cheap and effective method to control sodium adsorption ratio (SAR, which is a measure of the relative preponderance of sodium to calcium and magnesium) due to its high cation exchange capacity. In this study, a natural zeolite from Queensland was examined for its potential to treat CSG water to remove sodium ions to lower SAR and reduce the pH value. The results demonstrate that acid activated zeolite at 30%wt solid ratio can reduce the sodium content from 563.0 to 182.7 ppm; the pH from 8.74 to 6.95; and SAR from 70.3 to 18.5. Based on the results of the batch experiments, the sodium adsorption capacity of the acid-treated zeolite is three times greater than that of the untreated zeolite. Both the untreated and acid-treated zeolite samples were characterized using zeta potential, surface characterization, DTA/TG and particle size distribution in order to explain their adsorption behaviours. PMID:22841594

  9. Endodontic treatment of molars

    PubMed Central

    Habl, Claudia; Bodenwinkler, Andrea; Stürzlinger, Heidi

    2006-01-01

    Objective Commissioned by the German Institute of Medical Documentation and Information (DIMDI) the Austrian Health Institute (ÖBIG) prepared a HTA report on the long-term effectiveness of endodontic treatment (root canal treatment, RCT) of molars. The focus is to examine factors influencing the outcome of endodontic treatment and showing their impact on long-term results. Additionally, economic aspects of root canal treatment in Germany are discussed. Methodology By performing a systematic literature search in 29 databases (e.g. MEDLINE), the Cochrane Library and by hand searching two peer-reviewed endodontic journals the authors could identify 750 relevant articles, of which finally 18 qualified for assessment. Results The findings show that the most relevant factor influencing the long-term outcome of endodontic treatment is the preoperative status of a tooth. The lowest success rates are reported for molars with a preoperative devital or necrotic pulp and persisting periapical lesions (so called periapical disease). Discussion Even if there is no positive selection of patients and the RCT is performed by a normal dentist rather than an endodontist - a fact which is very common - long-term success rates of more then 90% are possible. The overall success rates for endodontic treatment of molars therefore seem to be similar to those of other tooth-types. Conclusions Especially primary, conventional (i.e. non-surgical) root canal treatment is an effective and efficient therapy for endodontically ill molars, especially if no large periapical lesion persists. Nonetheless, a long term successful endodontic therapy requires a thorough assessment of the pre-operative status of the molar and treatment according to established guidelines. PMID:21289954

  10. pH- and mol-ratio dependent formation of zinc(II) coordination polymers with iminodiacetic acid: Synthesis, spectroscopic, crystal structure and thermal studies

    SciTech Connect

    Ni Lubin; Zhang Ronghua; Liu Qiongxin; Xia Wensheng; Wang Hongxin; Zhou Zhaohui

    2009-10-15

    Three novel zinc coordination polymers (NH{sub 4}){sub n}[Zn(Hida)Cl{sub 2}]{sub n} (1), [Zn(ida)(H{sub 2}O){sub 2}]{sub n} (2), [Zn(Hida){sub 2}]{sub n}.4nH{sub 2}O (3) (H{sub 2}ida=iminodiacetic acid) and a monomeric complex [Zn(ida)(phen)(H{sub 2}O)].2H{sub 2}O (4) (phen=1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction methods. 1 and 2 form one-dimensional (1-D) chain structures, whereas 3 exhibits a three-dimensional (3-D) diamondoid framework with an open channel. The mononuclear complex 4 is extended into a 3-D supramolecular architecture through hydrogen bonds and pi-pi stacking. Interestingly, cyclic nonplanar tetrameric water clusters are observed that encapsulated in the 3-D lattice of 4. Based on {sup 1}H and {sup 13}C NMR observations, there is obvious coordination of complex 2 in solution, while 1 and 3 decompose into free iminodiacetate ligand. Monomer [Zn(ida)(H{sub 2}O){sub 3}] (5) is considered as a possible discrete species from 2. These coordination polymers can serve as good molecular precursors for zinc oxide. - Text3: Reaction of zinc salt with iminodiacetic acid afforded three new coordination polymers 1-3 and a monomer 4, which is dependent on pH value and molar ratio of the reactants.

  11. Complex coacervation of hyaluronic acid and chitosan: effects of pH, ionic strength, charge density, chain length and the charge ratio.

    PubMed

    Kayitmazer, A B; Koksal, A F; Kilic Iyilik, E

    2015-11-28

    Hyaluronic acid (HA) and chitosan (CH) can form nanoparticles, hydrogels, microspheres, sponges, and films, all with a wide range of biomedical applications. This variety of phases reflects the multiple pathways available to HA/CH complexes. Here, we use turbidimetry, dynamic light scattering, light microscopy and zeta potential measurements to show that the state of the dense phase depends on the molar ratio of HA carboxyl to CH amines, and is strongly dependent on their respective degrees of ionization, α and β. Due to the strong charge complementarity between HA and CH, electrostatic self-assembly takes place at very acidic pH, but is almost unobservable at ionic strength (I) ≥ 1.5 M NaCl. All systems display discontinuity in the I-dependence of the turbidity, corresponding to a transition from coacervates to flocculates. An increase in either polymer chain length or charge density enhances phase separation. Remarkably, non-stoichiometric coacervate suspensions form at zeta potentials far away from zero. This result is attributed to the entropic effects of chain semi-flexibility as well as to the charge mismatch between the two biopolymers. PMID:26406548

  12. Optimum concentration ratio of photodecomposable quencher to acid generator in chemically amplified extreme ultraviolet resists

    NASA Astrophysics Data System (ADS)

    Kozawa, Takahiro

    2015-12-01

    In chemically amplified resists used for ionizing radiations such as an extreme ultraviolet radiation, thermalized electrons and protons play important roles in pattern formation. Photodecomposable quenchers are important for 11 nm half-pitch fabrication because they capture both thermalized electrons and protons. However, their effects are complicated for the same reason. In this study, the optimum concentration ratio of photodecomposable quenchers to acid generators in terms of the trade-off relationships between resolution, line width roughness (LWR), and sensitivity was theoretically investigated, assuming line-and-space patterns of 11 nm half-pitch. To suppress LWR to less than 20% critical dimension (CD), the recommended total sensitizer concentration (the sum of acid generator and photodecomposable quencher concentrations) was in the range of 0.20-0.22 nm-3. The expected sensitivities were 30-40 mJ cm-2 when the resist performance of the latest chemically amplified resists was assumed. The optimum ratio of photodecomposable quencher concentration to the total sensitizer concentration was 0.55.

  13. Amino acid compositions in heated carbonaceous chondrites and their compound-specific nitrogen isotopic ratios

    NASA Astrophysics Data System (ADS)

    Chan, Queenie Hoi Shan; Chikaraishi, Yoshito; Takano, Yoshinori; Ogawa, Nanako O.; Ohkouchi, Naohiko

    2016-01-01

    A novel method has been developed for compound-specific nitrogen isotope compositions with an achiral column which was previously shown to offer high precision for nitrogen isotopic analysis. We applied the method to determine the amino acid contents and stable nitrogen isotopic compositions of individual amino acids from the thermally metamorphosed (above 500 °C) Antarctic carbonaceous chondrites Ivuna-like (CI)1 (or CI-like) Yamato (Y) 980115 and Ornans-like (CO)3.5 Allan Hills (ALH) A77003 with the use of gas chromatography/combustion/isotope ratio mass spectrometry. ALHA77003 was deprived of amino acids due to its extended thermal alteration history. Amino acids were unambiguously identified in Y-980115, and the δ15N values of selected amino acids (glycine +144.8 ‰; α-alanine +121.2 ‰) are clearly extraterrestrial. Y-980115 has experienced an extended period of aqueous alteration as indicated by the presence of hydrous mineral phases. It has also been exposed to at least one post-hydration short-lived thermal metamorphism. Glycine and alanine were possibly produced shortly after the accretion event of the asteroid parent body during the course of an extensive aqueous alteration event and have abstained from the short-term post-aqueous alteration heating due to the heterogeneity of the parent body composition and porosity. These carbonaceous chondrite samples are good analogs that offer important insights into the target asteroid Ryugu of the Hayabusa-2 mission, which is a C-type asteroid likely composed of heterogeneous materials including hydrated and dehydrated minerals.

  14. Comparison of the effect of salinity on the D/H ratio of fatty acids of heterotrophic and photoautotrophic microorganisms.

    PubMed

    Heinzelmann, Sandra M; Chivall, David; M'Boule, Daniela; Sinke-Schoen, Danielle; Villanueva, Laura; Damsté, Jaap S Sinninghe; Schouten, Stefan; van der Meer, Marcel T J

    2015-05-01

    The core metabolism of microorganisms has a major influence on the hydrogen isotopic composition of their fatty acids. Heterotrophic microorganisms produce fatty acids with a deuterium to hydrogen (D/H) ratio either slightly depleted or enriched in D compared to the growth water, while photo- and chemoautotrophic microorganisms produce fatty acids which are heavily depleted in D. However, besides metabolism other biochemical and environmental factors (i.e. biosynthetic pathways, growth phase and temperature) have been shown to affect the D/H ratio of fatty acids, and it is necessary to evaluate the magnitude of these effects compared to that of metabolism. Here, we show that the effect of salinity on the D/H ratio of fatty acids depends on the core metabolism of the microorganism. While fatty acids of the photoautotroph Isochrysis galbana become more enriched in D with increasing salinity (enrichment of 30-40‰ over a range of 25 salinity units), no effect of salinity on the D/H ratio of fatty acids of the heterotrophic Pseudomonas str. LFY10 was observed ((ε)lipid/water of the C16:0 fatty acid of ~120‰ over a range of 10 salinity units). This can likely be explained by the relative contributions of different H and nicotinamide adenine dinucleotide phosphate sources during fatty acid biosynthesis. PMID:25883110

  15. Relationship between mandibular condyle and angle fractures and the presence of mandibular third molars

    PubMed Central

    Mah, Deuk-Hyun; Moon, Seong-Yong; Oh, Ji-Su; You, Jae-Seek

    2015-01-01

    Objectives We retrospectively evaluated the impact of mandibular third molars on the occurrence of angle and condyle fractures. Materials and Methods This was a retrospective investigation using patient records and radiographs. The sample set consisted of 440 patients with mandibular fractures. Eruption space, depth and angulation of the third molar were measured. Results Of the 144 angle fracture patients, 130 patients had third molars and 14 patients did not. The ratio of angle fractures when a third molar was present (1.26 : 1) was greater than when no third molar was present (0.19 : 1; odds ratio, 6.58; P<0.001). Of the 141 condyle fractures patients, the third molar was present in 84 patients and absent in 57 patients. The ratio of condyle fractures when a third molar was present (0.56 : 1) was lower than when no third molar was present (1.90 : 1; odds ratio, 0.30; P<0.001). Conclusion The increased ratio of angle fractures with third molars and the ratio of condyle fractures without a third molar were statistically significant. The occurrence of angle and condyle fractures was more affected by the continuity of the cortical bone at the angle than by the depth of a third molar. These results demonstrate that a third molar can be a determining factor in angle and condyle fractures. PMID:25741462

  16. Biopolymer nanoparticles designed for polyunsaturated fatty acid vehiculization: Protein-polysaccharide ratio study.

    PubMed

    Perez, Adrián A; Sponton, Osvaldo E; Andermatten, Romina B; Rubiolo, Amelia C; Santiago, Liliana G

    2015-12-01

    Information about the design of biopolymer nanoparticles (BNPs) for polyunsaturated fatty acid (PUFA) vehiculization is provided. Linoleic acid (LA) was used as a model PUFA. The binding ability of LA to β-lactoglobulin (BLG) was applied for obtaining BLG-LA complexes. BLG-LA complex formation was monitored by fluorimetry and it was observed that a moderate heat treatment (60 °C, 10 min) enhanced BLG-LA complexation. Obtaining BNPs involved the electrostatic deposition of high methoxyl pectin (HMP) onto the BLG-LA complex surface. The phase behavior of biopolymer systems was discussed at different Prot:HMP ratio (RProt:HMP, wt.%) levels (1:1-6:1). Absorbance at 600 nm, particle size, and ζ potential were analyzed at pH 4.0. At 1:1-2:1 RProt:HMP, BNPs showed appreciable turbidity, a nanometric diameter (337-364 nm), and a negative ζ potential. Finally, intrinsic and extrinsic fluorimetry was used for examining the HMP protective role at the LA binding site. At 2:1 RProt:HMP, HMP cover could promote significant LA protection in BNPs. PMID:26041229

  17. Postglacial climate reconstruction based on compound-specific D/H ratios of fatty acids from Blood Pond, New England

    NASA Astrophysics Data System (ADS)

    Hou, Juzhi; Huang, Yongsong; Wang, Yi; Shuman, Bryan; Oswald, W. Wyatt; Faison, Edward; Foster, David R.

    2006-03-01

    We determined hydrogen isotope ratios of individual fatty acids in a sediment core from Blood Pond, Massachusetts, USA, in order to reconstruct climate changes during the past 15 kyr. In addition to palmitic acid (C16n-acid), which has been shown to record lake water D/H ratios, our surface sediments and down core data indicate that behenic acid (C22n-acid), produced mainly by aquatic macrophytes, is also effective for capturing past environmental change. Calibration using surface sediments from two transects across eastern North America indicates that behenic acid records δD variation of lake water. Down core variations in δD values of behenic acid and pollen taxa are consistent with the known climate change history of New England. By evaluating the hypothesis that D/H fractionations of long chain even numbered fatty acids (C24-C32n-acids) relative to lake water provide independent estimates of relative humidity during the growing season, we find that differences between lake-level records and isotopically inferred humidity estimates may provide useful insight into seasonal aspects of the hydrologic cycle. Combined analyses of D/H of short and long chain fatty acids from lake sediment cores thus allow reconstructions of both past temperature and growing season relative humidity. Comparison of δD records from two lakes in New England provides critical information on regional climate variation and abrupt climate change, such as the 8.2 ka event.

  18. A panel of free fatty acid ratios to predict the development of metabolic abnormalities in healthy obese individuals

    PubMed Central

    Zhao, Linjing; Ni, Yan; Ma, Xiaojing; Zhao, Aihua; Bao, Yuqian; Liu, Jiajian; Chen, Tianlu; Xie, Guoxiang; Panee, Jun; Su, Mingming; Yu, Herbert; Wang, Congrong; Hu, Cheng; Jia, Weiping; Jia, Wei

    2016-01-01

    Increasing evidences support that metabolically healthy obese (MHO) is a transient state. However, little is known about the early markers associated with the development of metabolic abnormalities in MHO individuals. Serum free fatty acids (FFAs) profile is highlighted in its association with obesity-related insulin resistance, type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD). To examine the association of endogenous fatty acid metabolism with future development of metabolic abnormalities in MHO individuals, we retrospectively analyzed 24 [product FFA]/[precursor FFA] ratios in fasting sera and clinical data from 481 individuals who participated in three independent studies, including 131 metabolic healthy subjects who completed the 10-year longitudinal Shanghai Diabetes Study (SHDS), 312 subjects cross-sectionally sampled from the Shanghai Obesity Study (SHOS), and 38 subjects who completed an 8-week very low carbohydrate diet (VLCD) intervention study. Results showed that higher baseline level of oleic acid/stearic acid (OA/SA), and lower levels of stearic acid/palmitic acid (SA/PA) and arachidonic acid/dihomo-γ-linolenic acid (AA/DGLA) ratios were associated with higher rate of MHO to MUO conversion in the longitudinal SHDS. Further, the finding was validated in the cross-sectional and interventional studies. This panel of FFA ratios could be used for identification and early intervention of at-risk obese individuals. PMID:27344992

  19. A panel of free fatty acid ratios to predict the development of metabolic abnormalities in healthy obese individuals.

    PubMed

    Zhao, Linjing; Ni, Yan; Ma, Xiaojing; Zhao, Aihua; Bao, Yuqian; Liu, Jiajian; Chen, Tianlu; Xie, Guoxiang; Panee, Jun; Su, Mingming; Yu, Herbert; Wang, Congrong; Hu, Cheng; Jia, Weiping; Jia, Wei

    2016-01-01

    Increasing evidences support that metabolically healthy obese (MHO) is a transient state. However, little is known about the early markers associated with the development of metabolic abnormalities in MHO individuals. Serum free fatty acids (FFAs) profile is highlighted in its association with obesity-related insulin resistance, type 2 diabetes mellitus (T2DM) and cardiovascular diseases (CVD). To examine the association of endogenous fatty acid metabolism with future development of metabolic abnormalities in MHO individuals, we retrospectively analyzed 24 [product FFA]/[precursor FFA] ratios in fasting sera and clinical data from 481 individuals who participated in three independent studies, including 131 metabolic healthy subjects who completed the 10-year longitudinal Shanghai Diabetes Study (SHDS), 312 subjects cross-sectionally sampled from the Shanghai Obesity Study (SHOS), and 38 subjects who completed an 8-week very low carbohydrate diet (VLCD) intervention study. Results showed that higher baseline level of oleic acid/stearic acid (OA/SA), and lower levels of stearic acid/palmitic acid (SA/PA) and arachidonic acid/dihomo-γ-linolenic acid (AA/DGLA) ratios were associated with higher rate of MHO to MUO conversion in the longitudinal SHDS. Further, the finding was validated in the cross-sectional and interventional studies. This panel of FFA ratios could be used for identification and early intervention of at-risk obese individuals. PMID:27344992

  20. Slight Fermentation with Lactobacillus fermentium Improves the Taste (Sugar:Acid Ratio) of Citrus (Citrus reticulata cv. chachiensis) Juice.

    PubMed

    Yu, Yuanshan; Xiao, Gengsheng; Xu, Yujuan; Wu, Jijun; Fu, Manqin; Wen, Jing

    2015-11-01

    The aim of this study was to evaluate the hypothesis that fermentation with Lactobacillus fermentium, which can metabolize citric acid, could be applied in improving the taste (sugar:acid ratio) of citrus juice. During fermentation, the strain of L. fermentium can preferentially utilize citric acid of citrus (Citrus reticulata cv. Chachiensis) juice to support the growth without the consumption of sugar. After 6 h of fermentation with L. fermentium at 30 °C, the sugar:acid ratio of citrus juice increased to 22:1 from 12:1, which resulted in that the hedonic scores of sweetness, acidity and overall acceptability of fermented-pasteurized citrus juice were higher than the unfermented-pasteurized citrus juice. Compared with unfermented-pasteurized citrus juice, the ORAC value and total amino acid showed a reduction, and no significant change (P > 0.05) in the L*, a*, b*, total soluble phenolics and ascorbic acid (Vc) content in the fermented-pasteurized citrus juice was observed as compared with unfermented-pasteurized citrus juice. Hence, slight fermentation with L. fermentium can be used for improving the taste (sugar:acid ratio) of citrus juice with the well retaining of quality. PMID:26447635

  1. The importance of the omega-6/omega-3 fatty acid ratio in cardiovascular disease and other chronic diseases.

    PubMed

    Simopoulos, Artemis P

    2008-06-01

    Several sources of information suggest that human beings evolved on a diet with a ratio of omega-6 to omega-3 essential fatty acids (EFA) of approximately 1 whereas in Western diets the ratio is 15/1-16.7/1. Western diets are deficient in omega-3 fatty acids, and have excessive amounts of omega-6 fatty acids compared with the diet on which human beings evolved and their genetic patterns were established. Excessive amounts of omega-6 polyunsaturated fatty acids (PUFA) and a very high omega-6/omega-3 ratio, as is found in today's Western diets, promote the pathogenesis of many diseases, including cardiovascular disease, cancer, and inflammatory and autoimmune diseases, whereas increased levels of omega-3 PUFA (a lower omega-6/omega-3 ratio), exert suppressive effects. In the secondary prevention of cardiovascular disease, a ratio of 4/1 was associated with a 70% decrease in total mortality. A ratio of 2.5/1 reduced rectal cell proliferation in patients with colorectal cancer, whereas a ratio of 4/1 with the same amount of omega-3 PUFA had no effect. The lower omega-6/omega-3 ratio in women with breast cancer was associated with decreased risk. A ratio of 2-3/1 suppressed inflammation in patients with rheumatoid arthritis, and a ratio of 5/1 had a beneficial effect on patients with asthma, whereas a ratio of 10/1 had adverse consequences. These studies indicate that the optimal ratio may vary with the disease under consideration. This is consistent with the fact that chronic diseases are multigenic and multifactorial. Therefore, it is quite possible that the therapeutic dose of omega-3 fatty acids will depend on the degree of severity of disease resulting from the genetic predisposition. A lower ratio of omega-6/omega-3 fatty acids is more desirable in reducing the risk of many of the chronic diseases of high prevalence in Western societies, as well as in the developing countries. PMID:18408140

  2. Gene expression, serum amino acid levels, and growth performance of pigs fed dietary leucine and lysine at different ratios.

    PubMed

    García, H; Morales, A; Araiza, A; Htoo, J K; Cervantes, M

    2015-01-01

    We examined 96 pigs (28.1 ± 0.83 kg) to analyze the effect of Leu:Lys ratios on expression of the cationic amino acid transporters b(0,+) and CAT-1 in the jejunum and liver as well as myosin expression in 2 muscles to estimate the optimum standardized ileal digestible (SID) Leu:Lys ratio for growth rate and efficiency. A wheat-and wheat bran-based diets were formulated to meet the requirements of SID amino acids other than Leu (0.70%) and Lys (0.80%). L-Leu was added to the basal diet in 5 SID Leu:Lys ratios (88, 100, 120, 140, and 160% in diets 1-5). Tissue samples were collected from 8 pigs with ratios of 88, 120, and 160%. Relative expression of b(0,+), CAT-1, and myosin was analyzed. b(0,+) expression in the jejunum was higher but lower in the liver of pigs with the 120% ratio compared to those with the 88 or 160% ratio; myosin expression in longissimus dorsi was also higher in pigs with the 120% ratio (P < 0.05). CAT-1 was lower in the jejunum and longissimus dorsi of pigs with 120 or 160% ratios than in pigs with 88%. Serum concentration of nearly all amino acids decreased with excess dietary Leu (P < 0.05). The SID Leu:Lys of 104 and 109% optimized average daily gain and feed conversion ratio, respectively. Thus, the dietary Leu:Lys ratio affects the expression of genes coding for amino acid transporters and myosin, the availability of Lys, and the growth rate and efficiency in pigs. PMID:25867302

  3. Molar Incisor Hypomineralization.

    PubMed

    Rao, Murali H; Aluru, Srikanth C; Jayam, Cheranjeevi; Bandlapalli, Anila; Patel, Nikunj

    2016-01-01

    Molar incisor hypomineralization (MIH) is a developmental defect affecting teeth. High prevalence rates of MIH and its clinical implications are significant for both the patients and clinicians. A wide variation in defect prevalence (2.4-40.2%) is reported. It seems to differ with regions and various birth cohorts. Some of the recent prevalence studies are tabulated. Patient implications include hypersensitive teeth, rapid progression of caries, mastication impairment due to rapid attrition, and esthetic repercussions. Implications for clinicians include complexity in treatment planning and treatment implementation, poor prognosis of the restorations, difficulty in achieving pain control during treatment, and behavior management problems. Intention of this paper is to review the etio-pathogenesis, prevalence, clinical features, diagnostic features, and eventually present a sequential treatment approach, i.e., in accordance with current clinical practice guidelines. PMID:27595731

  4. Effects of dietary n-6:n-3 PUFA ratio on fatty acid composition, free amino acid profile and gene expression of transporters in finishing pigs.

    PubMed

    Li, Fengna; Duan, Yehui; Li, Yinghui; Tang, Yulong; Geng, Meimei; Oladele, Oso Abimbola; Kim, Sung Woo; Yin, Yulong

    2015-03-14

    Revealing the expression patterns of fatty acid and amino acid transporters as affected by dietary n-6:n-3 PUFA ratio would be useful for further clarifying the importance of the balance between n-6 and n-3 PUFA. A total of ninety-six finishing pigs were fed one of four diets with the ratio of 1:1, 2·5:1, 5:1 and 10:1. Pigs fed the dietary n-6:n-3 PUFA ratio of 5:1 had the highest (P< 0·05) daily weight gain, and those fed the dietary n-6:n-3 PUFA ratio of 1:1 had the largest loin muscle area (P< 0·01). The concentration of n-3 PUFA was raised as the ratio declined (P< 0·05) in the longissimus dorsi and subcutaneous adipose tissue. The contents of tryptophan, tasty amino acids and branched-chain amino acids in the longissimus dorsi were enhanced in pigs fed the dietary n-6:n-3 PUFA ratios of 1:1-5:1. The mRNA expression level of the fatty acid transporter fatty acid transport protein-1 (FATP-1) was declined (P< 0·05) in the longissimus dorsi of pigs fed the dietary n-6:n-3 PUFA ratios of 1:1-5:1, and increased (P< 0·05) in the subcutaneous adipose tissue of pigs fed the dietary n-6:n-3 PUFA ratios of 5:1 and 10:1. The expression profile of FATP-4 was similar to those of FATP-1 in the adipose tissue. The mRNA expression level of the amino acid transceptors LAT1 and SNAT2 was up-regulated (P< 0·05) in the longissimus dorsi of pigs fed the dietary n-6:n-3 PUFA ratios of 1:1 and 2·5:1. In conclusion, maintaining the dietary n-6:n-3 PUFA ratios of 1:1-5:1 would facilitate the absorption and utilisation of fatty acids and free amino acids, and result in improved muscle and adipose composition. PMID:25704496

  5. [Long-term and short-term effects of propionic/acetic acid ratios on metabolism of glycogen-accumulating organisms].

    PubMed

    Yao, Ying; Chen, Yin-guang; Ma, Min; Gu, Guo-wei

    2007-09-01

    Three activated sludges enriched with glycogen accumulating organisms (GAO) were acclimatized respectively with different ratios of propionic to acetic acid (i.e. biomass SBR-A, C and E) . The effect of different ratios of propionic/acetic acid on the metabolism of long-term cultivated GAO was investigated. Cultivated with high propionic/acetic acid ratio, GAO consumed less glycogen and synthesized less poly-beta-hydroxyalkanoates (PHA) in the anaerobic phase, and in the aerobic phase accumulated less glycogen and degraded less PHA, and at the same time the microbial growth was lower. When the carbon mole of acetic acid equaled that of propionic acid in the influent, GAO utilized acetic acid faster than propionic acid. Batch tests were carried out with biomass SBR-A and SBR-E to study the transient response of long-term cultivated GAO to short-term change of propionic/acetic acid ratio. The GAO cultivated with a high propionic/acetic acid ratio was able to utilize acetic acid immediately when the concentration of acetic acid in the feed suddenly increased. But when the biomass cultivated with a low propionic/acetic acid ratio was feed with high ratio propionic/acetic acid wastewater, the propionic acid uptake rate was only 41.1% of the rate of the GAO long-term cultivated with high propionic/acetic acid. The sudden increase of propionic/acetic acid ratio could effectively inhibit the metabolism of GAO. PMID:17990541

  6. Improving the Reliability of Optimal In-Feed Amino Acid Ratios Based on Individual Amino Acid Efficiency Data from N Balance Studies in Growing Chicken.

    PubMed

    Wecke, Christian; Liebert, Frank

    2013-01-01

    Three consecutive nitrogen balance experiments with fast-growing male broiler chickens (ROSS 308), both during starter and grower periods, were conducted to determine the ideal ratios of several indispensable amino acids relative to lysine. The control diets based on corn, wheat, fishmeal, field peas, wheat gluten and soybean oil were formulated by computer optimizing to meet the assumed ideal amino acid ratios and to fulfill both the energy and nutrient requirements of growing chicken. According to principles of the diet dilution technique, balanced control diets were diluted by wheat starch and refilled by crystalline amino acids and remaining feed ingredients, except the amino acid under study. The lysine, threonine, tryptophan, arginine, isoleucine and valine diluted diets resulted in significantly lower protein quality as compared to control diet, especially following increased dietary lysine supply (experiments II and III) and stronger amino acid dilution (experiment III). Accordingly, the limiting position of individual amino acids was confirmed, and the derived amino acid efficiency data were utilized to derive ideal amino acid ratios for the starter period: Lys (100): Thr (60): Trp (19): Arg (105): Ile (55): Val (63); and the grower period: Lys (100): Thr (62): Trp (17): Arg (105): Ile (65): Val (79). PMID:26479521

  7. Stable carbon isotope ratio and composition of microbial fatty acids in tropical soils.

    PubMed

    Burke, Roger A; Molina, Marirosa; Cox, Julia E; Osher, Laurie J; Piccolo, Marisa C

    2003-01-01

    The soil microbial community plays a critical part in tropical ecosystem functioning through its role in the soil organic matter (SOM) cycle. This study evaluates the relative effects of soil type and land use on (i) soil microbial community structure and (ii) the contribution of SOM derived from the original forest vegetation to the functioning of pasture and sugarcane (Saccharum spp.) ecosystems. We used principal components analysis (PCA) of soil phospholipid fatty acid (PLFA) profiles to evaluate microbial community structure and PLFA stable carbon isotope ratios (delta13C) as indicators of the delta13C of microbial substrates. Soil type mainly determined the relative proportions of gram positive versus gram negative bacteria whereas land use primarily determined the relative proportion of fungi, protozoa, and actinomycetes versus other types of microorganisms. Comparison of a simple model to our PLFA delta13C data from land use chronosequences indicates that forest-derived SOM is actively cycled for appreciably longer times in sugarcane ecosystems developed on Andisols (mean turnover time = 50 yr) than in sugarcane ecosystems developed on an Oxisol (mean turnover time = 13 yr). Our analyses indicate that soil chronosequence PLFA delta13C measurements can be useful indicators of the contribution that SOM derived from the original vegetation makes to continued ecosystem function under the new land use. PMID:12549559

  8. Carbon isotope ratios in crassulacean Acid metabolism plants: seasonal patterns from plants in natural stands.

    PubMed

    Szarek, S R

    1976-09-01

    A year round study of photosynthesis and carbon isotope fractionation was conducted with plants of Opuntia phaeacantha Engelm. and Yucca baccata Torr. occurring in natural stands at elevations of 525, 970, 1450 and 1900 m. Plant water potentials and the daytime pattern of (14)CO(2) photosynthesis were similar for all cacti along the elevational gradient, despite significant differences in temperature regime and soil water status. Carbon isotope ratios of total tissue and soluble extract fractions were relatively constant throughtout the entire year. Additionally, the sigma(13)C values were similar in all plants of the same species along the elevational gradient, i.e. -12.5 +/- 0.86 per thousand for O. phaeacantha and -15.7 +/- 0.95 per thousand for Y. baccata. The results of this study indicate Crassulacean acid metabolism predominates as the major carbon pathway of these plants, which do not facultatively utilize the reductive pentose phosphate cycle of photosynthesis as the primary carboxylation reaction. PMID:16659680

  9. Ratios of regioisomers of triacylglycerols containing dihydroxy fatty acids in castor oil by mass spectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The triacylglycerols (TAG) containing dihydroxy fatty acids have been recently identified by mass spectrometry in castor oil. These new dihydroxy fatty acids were proposed earlier as 11,12-dihydroxy-9-octadecenoic acid (diOH18:1), 11,12-dihydroxy-9,13-octadecadienoic acid (diOH18:2) and 11,12-dihydr...

  10. The effects of season on fatty acid composition and ω3/ω6 ratios of northern pike ( Esox lucius L., 1758) muscle lipids

    NASA Astrophysics Data System (ADS)

    Mert, Ramazan; Bulut, Sait; Konuk, Muhsin

    2015-01-01

    In the present study, the effects of season on fatty acid composition, total lipids, and ω3/ω6 ratios of northern pike muscle lipids in Kizilirmak River (Kirikkale, Turkey) were investigated. A total of 35 different fatty acids were determined in gas chromatography. Among these, palmitic, oleic, and palmitoleic acids had the highest proportion. The main polyunsaturated fatty acids (PUFAs) were found to be docosahexaenoic acid, eicosapentaenoic acid, and arachidonic acid. There were more PUFAs than monounsaturated fatty acids (MUFA) in all seasons. Similarly, the percentages of ω3 fatty acids were higher than those of total ω6 fatty acids in the fatty acid composition. ω3/ω6 ratios were calculated as 1.53, 1.32, 1.97, and 1.71 in spring, summer, autumn and winter, respectively. Overall, we found that the fatty acid composition and ω3/ω6 fatty acid ratio in the muscle of northern pike were significantly influenced by season.

  11. Postglacial Climate Reconstruction Based on Compound-Specific D/H Ratios of Fatty Acids From Blood Pond, New England

    NASA Astrophysics Data System (ADS)

    Hou, J.; Huang, Y.; Shuman, B.; Oswald, W.; Faison, E.; Foster, D.

    2005-12-01

    Compounds of aquatic sources are of particular interest for compound-specific hydrogen isotope analysis because of their potential to record lake water D/H ratios which respond strongly to climatic changes (e.g.,temperature change). C27,C28 sterols and palmitic acid (C16 n-acid) have been suggested to record D/H variation of lake and ocean water (Sauer et al., 2001, Huang et al., 2002, 2004). Here we report a new proxy of lake water isotope composition. Surface calibration from two transects indicates that behenic acid (C22 n-acid) captures δD variation of lake water from two transects across eastern North America (δDBA=0.8185*δDwater-140.01,R=0.898;p<0.05). We also determined hydrogen isotope ratios of individual fatty acids in a sediment core from Blood Pond, MA, in order to reconstruct climate change during the past 16 ka. Downcore variations in δD values of behenic acid and pollen taxa are highly consistent with known climate change histories in New England. Behenic acid is produced mainly by aquatic macrophytes. D/H fractionations of long chain even numbered fatty acids relative to lake water provide independent estimation of growth season relative humidity. Combined analyses of hydrogen isotopic ratios of short and long chain fatty acids from lake sediment cores thus allow reconstruction of both past temperature and effective moisture conditions. Comparison of δD records from two lakes in New England provides critical information on regional climate variation and abrupt climate change, such as 8.2 ka event. We also demonstrate that the chain length of fatty acids varies systematically in response to vegetation changes in the sediment core, providing additional data for paleoenvironmental assessment.

  12. Alcohol-to-acid ratio and substrate concentration affect product structure in chain elongation reactions initiated by unacclimatized inoculum.

    PubMed

    Liu, Yuhao; Lü, Fan; Shao, Liming; He, Pinjing

    2016-10-01

    The objective of the study was to investigate whether the ratio of ethanol to acetate affects yield and product structure in chain elongation initiated by unacclimatized mixed cultures. The effect of varying the substrate concentration, while maintaining the same ratio of alcohol to acid, was also investigated. With a high substrate concentration, an alcohol to acid ratio >2:1 provided sufficient electron donor capacity for the chain elongation reaction. With an ethanol to acetate ratio of 3:1 (300mM total carbon), the highest n-caproate concentration (3033±98mg/L) was achieved during the stable phase of the reaction. A lower substrate concentration (150mM total carbon) gave a lower yield of products and led to reduced carbon transformation efficiency compared with other reaction conditions. The use of unacclimatized inoculum in chain elongation can produce significant amounts of odd-carbon-number carboxylates as a result of protein hydrolysis. PMID:27469095

  13. Effects of dietary n-6:n-3 fatty acid ratio and vitamin E on semen quality, fatty acid composition and antioxidant status in boars.

    PubMed

    Liu, Q; Zhou, Y F; Duan, R J; Wei, H K; Jiang, S W; Peng, J

    2015-11-01

    The aim of the present study was to evaluate the effects of dietary n-6:n-3 fatty acid (FA) ratio and vitamin E on the semen quality, FA composition and antioxidant status of boars. Forty-eight Landrace boars were randomly distributed in a 3×2 factorial design with three n-6:n-3 FA ratios (14.4, 6.6 and 2.2) by the inclusion of three oil sources (soybean, fish/soybean, fish) and two vitamin E levels (200 and 400mg/kg). During the 8 weeks of treatment, semen parameters were evaluated. Serum, sperm and seminal plasma samples were taken at 0 and 8 weeks to monitor the FA composition and antioxidant status. Results showed that the 6.6 and 2.2 dietary ratios very effectively increased docosahexaenoic acid (DHA) and n-3 polyunsaturated fatty acid (PUFA) and decreased docosapentaenoic acid (DPA) and n-6:n-3 ratio in spermatozoa. The 6.6 dietary ratio contributed to a greater progressive sperm motility (P<0.05) than the 14.4 and 2.2 dietary ratio, and this ratio also enhanced the superoxide dismutase (SOD) and total antioxidant capacity (TAC) (P<0.05) in seminal plasma more significantly than the other two ratios at week 8. Compared with 200mg/kg supplementation of vitamin E, 400mg/kg supplementation of vitamin E increased the progressive sperm motility, SOD of sperm, TAC and SOD of seminal plasma and serum, and decreased sperm malondialdehyde (MDA) (P<0.05). In conclusion, the 6.6 dietary ratio and 400mg/kg vitamin E supplementation improve progressive sperm motility by modifying the sperm FA composition and antioxidant status. PMID:26417649

  14. Controversy of the third molars.

    PubMed

    Pitekova, L; Satko, I

    2009-01-01

    Third molars are teeth that have little functional value and a relatively high rate of associated pain and disease. Their value as a part of the dentition of modern people is dubious. Our aim is to review the evolution, morbidity and complications of the third molars (Ref. 19). Full Text (Free, PDF) www.bmj.sk. PMID:19408843

  15. Effects of Benzoic Acid and Dietary Calcium:Phosphorus Ratio on Performance and Mineral Metabolism of Weanling Pigs

    PubMed Central

    Gutzwiller, A.; Schlegel, P.; Guggisberg, D.; Stoll, P.

    2014-01-01

    In a 2×2 factorial experiment the hypotheses tested were that the metabolic acid load caused by benzoic acid (BA) added to the feed affects bone mineralization of weanling pigs, and that a wide dietary calcium (Ca) to phosphorus (P) ratio in phytase-supplemented feeds with a marginal P concentration has a positive effect on bone mineralization. The four experimental diets, which contained 0.4% P and were supplemented with 1,000 FTU phytase/kg, contained either 5 g BA/kg or no BA and either 0.77% Ca or 0.57% Ca. The 68 four-week-old Large White pigs were fed the experimental diets ad libitum for six weeks and were then slaughtered. Benzoic acid increased feed intake (p = 0.009) and growth rate (p = 0.051), but did not influence the feed conversion ratio (p>0.10). Benzoic acid decreased the pH of the urine (p = 0.031), but did not affect breaking strength and mineralization of the tibia (p>0.10). The wide Ca:P ratio decreased feed intake (p = 0.034) and growth rate (p = 0.007) and impaired feed the conversion ratio (p = 0.027), but increased the mineral concentration in the fat-free DM of the tibia (p = 0.013) without influencing its breaking strength (p>0.10). The observed positive effect of the wide Ca:P ratio on bone mineralization may be attributed, at least in part, to the impaired feed conversion ratio, i.e. to the higher feed intake and consequently to the higher mineral intake per kg BW gain. The negative impact on animal performance of the wide dietary Ca:P ratio outweighs its potentially positive effect on bone mineralization, precluding its implementation under practical feeding conditions. PMID:25049984

  16. USE OF STABLE CARBON ISOTOPE RATIOS OF FATTY ACIDS TO EVALUATE MICROBIAL CARBON SOURCES IN TERRESTRIAL ENVIRONMENTS

    EPA Science Inventory

    We use measurements of the concentration and stable carbon isotopic ratio (D 13C) of individual microbial phospholipid fatty acids (PLFAs) in soils as indicators of live microbial biomass levels and microbial carbon source. We found that intensive sugar cane cultivation leads to ...

  17. USE OF THE COMPOSITION AND STABLE CARBON ISOTOPE RATIO OF MICROBIAL FATTY ACIDS TO STUDY CARBON CYCLING

    EPA Science Inventory

    We use measurements of the concentration and stable carbon isotopic ratio (Gamma 13C) of individual microbial phospholipid fatty acids (PLFAS) in soils and sediments as indicators of live microbial biomass levels and microbial carbon source. For studies of soil organic matter (SO...

  18. Determining the oleic/linoleic acid ratio in a single peanut seed: a comparison of two methods

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut varieties with high oleic/linoleic acid ratios have become preferred by the peanut industry due to their increased shelf life and improved health benefits. Many peanut breeding programs are trying to incorporate the high oleic trait into new and improved varieties and are in need of diagnost...

  19. Comparing three methods used to determine the oleic/linoleic acid ratio in a single peanut seed

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanut varieties with high oleic/linoleic acid ratios have become preferred by the peanut industry due to their increased shelf life and improved health benefits. Many peanut breeding programs are trying to incorporate the high oleic trait into new and improved varieties and are in need of diagnost...

  20. Meal composition and plasma amino acid ratios: Effect of various proteins or carbohydrates, and of various protein concentrations

    NASA Technical Reports Server (NTRS)

    Yokogoshi, Hidehiko; Wurtman, Richard J.

    1986-01-01

    The effects of meals containing various proteins and carbohydrates, and of those containing various proportions of protein (0 percent to 20 percent of a meal, by weight) or of carbohydrate (0 percent to 75 percent), on plasma levels of certain large neutral amino acids (LNAA) in rats previously fasted for 19 hours were examined. Also the plasma tryptophan ratios (the ratio of the plasma trytophan concentration to the summed concentrations of the other large neutral amino acids) and other plasma amino acid ratios were calculated. (The plasma tryptophan ratio has been shown to determine brain tryptophan levels and, thereby, to affect the synthesis and release of the neurotransmitter serotonin). A meal containing 70 percent to 75 percent of an insulin-secreting carbohydrate (dextrose or dextrin) increased plasma insulin levels and the tryptophan ratio; those containing 0 percent or 25 percent carbohydrate failed to do so. Addition of as little as 5 percent casein to a 70 percent carbohydrate meal fully blocked the increase in the plasma tryptophan ratio without affecting the secretion of insulin - probably by contributing much larger quantities of the other LNAA than of tryptophan to the blood. Dietary proteins differed in their ability to suppress the carbohydrate-induced rise in the plasma tryptophan ratio. Addition of 10 percent casein, peanut meal, or gelatin fully blocked this increase, but lactalbumin failed to do so, and egg white did so only partially. (Consumption of the 10 percent gelatin meal also produced a major reduction in the plasma tyrosine ratio, and may thereby have affected brain tyrosine levels and catecholamine synthesis.) These observations suggest that serotonin-releasing neurons in brains of fasted rats are capable of distinguishing (by their metabolic effects) between meals poor in protein but rich in carbohydrates that elicit insulin secretion, and all other meals. The changes in brain serotonin caused by carbohydrate-rich, protein

  1. Effect of precipitation, geographical location and biosynthesis on New Zealand milk powder bulk and fatty acids D/H ratios

    NASA Astrophysics Data System (ADS)

    Frew, R.; Emad Ehtesham, R.; Van Hale, R.; Hayman, A.; Baisden, T.

    2012-04-01

    D/H ratio measurements provide useful information for the investigation of biogeochemical influences on natural and agricultural produce, particularly with application to food traceability and authentication. Numerous studies have shown that variation of a product's D/H ratio is influenced by both environmental factors and biological processes. This study investigates the D/H ratio of New Zealand milk powder and individual fatty acids, and causal determinants of isotopic variation. One of the key environmental factors is precipitation, and the D/H ratio "isoscaping" of NZ has been undertaken. New Zealand provides a unique geography for these kinds of study in terms of proximity to the ocean and natural geographical variability from sea level to elevations as high as 3700 m. Milk powder samples were collected from different geographical regions from milk processing units, which were supplied by producers in the immediate region. H/D ratios of bulk milk powder and of individual fatty acids were determined. Initial comparison of the precipitation and milk powder bulk D/H data show a very good differentiation from north to southernmost parts of New Zealand and a relation between rain and milk bulk D/H abundance ratio. Almost 98% of milk FAs are in the form of triglycerides that have been extracted and hydrolysed to free FAs. Free FAs were esterified and analyzed with GC-IRMS. Individual FAs show variation in D/H ratio, and all values are depleted relative to the precipitation data. The difference in D/H ratio amongst individual FAs reflects the geographical environment and biological processes i.e. micro-organisms activity in the rumen of the cow. Short chain FAs (less than 8 carbons), particularly C4 (Butyric acid), appear to be key determinants. The variation in the data can be rationalized using statistical multivariate analysis.

  2. Control of oenological products: discrimination between different botanical sources of L-tartaric acid by isotope ratio mass spectrometry.

    PubMed

    Moreno Rojas, Jose Manuel; Cosofret, Sorin; Reniero, Fabiano; Guillou, Claude; Serra, Francesca

    2007-01-01

    Following previous studies on counterfeit of wines with synthetic ingredients, the possibility of frauds by natural external L-tartaric acid has also been investigated. The aim of this research was to map the stable isotope ratios of L-tartaric acid coming from botanical species containing large amounts of this compound: grape and tamarind. Samples of L-tartaric acid were extracted from the pulp of tamarind fruits originating from several countries and from grape must. delta(13)C and delta(18)O were measured for all samples. Additional delta(2)H measurements were performed as a complementary analysis to help discrimination of the botanical origin. Different isotopic patterns were observed for the different botanical origins. The multivariate statistical analysis of the data shows clear discrimination among the different botanical and synthetic sources. This approach could be a complementary tool for the control of L-tartaric acid used in oenology. PMID:17610238

  3. Quantitative prediction and molar description of the environment

    PubMed Central

    Baum, William M.

    1989-01-01

    Molecular explanations of behavior, based on momentary events and variables that can be measured each time an event occurs, can be contrasted with molar explanations, based on aggregates of events and variables that can be measured only over substantial periods of time. Molecular analyses cannot suffice for quantitative accounts of behavior, because the historical variables that determine behavior are inevitably molar. When molecular explanations are attempted, they always depend on hypothetical constructs that stand as surrogates for molar environmental variables. These constructs allow no quantitative predictions when they are vague, and when they are made precise, they become superfluous, because they can be replaced with molar measures. In contrast to molecular accounts of phenomena like higher responding on ratio schedules than interval schedules and free-operant avoidance, molar accounts tend to be simple and straightforward. Molar theory incorporates the notion that behavior produces consequences that in turn affect the behavior, the notion that behavior and environment together constitute a feedback system. A feedback function specifies the dependence of consequences on behavior, thereby describing properties of the environment. Feedback functions can be derived for simple schedules, complex schedules, and natural resources. A complete theory of behavior requires describing the environment's feedback functions and the organism's functional relations. Molar thinking, both in the laboratory and in the field, can allow quantitative prediction, the mark of a mature science. PMID:22478030

  4. trans-cis Configuration regulated supramolecular polymer gels and chirality transfer based on a bolaamphiphilic histidine and dicarboxylic acids.

    PubMed

    Chen, Chunfeng; Wang, Tianyu; Fu, Yunzhi; Liu, Minghua

    2016-01-25

    Supramolecular polymer gels based on the co-assembly of bolaamphiphilic l-histidine(BolaHis) and dicarboxylic acids are dependent on the molar ratios, flexibility and cis-trans configuration of acid molecules. Thus, oligomerized rigid cis-maleic acid or flexible trans-cyclohexane dicarboxylic acid can form chiral supramolecular polymer gels with l-BolaHis. PMID:26617194

  5. Efficiency of fatty acid synthesis by oleaginous yeasts: Prediction of yield and fatty acid cell content from consumed C/N ratio by a simple method.

    PubMed

    Granger, L M; Perlot, P; Goma, G; Pareilleux, A

    1993-11-20

    In nitrogen-limited media, growth and fatty acid formation by the oleaginous yeast Rhodotorula glutinis, i.e., yield and fatty acid cell content, have been characterized regarding carbon and nitrogen availabilities. It was shown that the formation of fatty acid free biomass was limited by nitrogen availability, whereas the fatty acid production was directly dependent on the consumed C/N ratio. According to these observations, the fraction of substrate consumed for fatty acid synthesis was estimated by using a simple method based on the actual yields, i.e., the mass of carbon source strictly converted into fatty acids and fatty acid free biomass. From these results, relationships were established allowing to predict in a simple and performing manner the maximal attainable fatty acid cell content and yield from the available carbon and nitrogen. These relationships were validated by using experimental data obtained by various authors with different yeast strains, and the proposed method was compared to the energetic and mass balance method previously described. PMID:18609663

  6. Relation between stable isotope ratios in human red blood cells and hair: implications for using the nitrogen isotope ratio of hair as a biomarker of eicosapentaenoic acid and docosahexaenoic acid1234

    PubMed Central

    Nash, Sarah H; Kristal, Alan R; Boyer, Bert B; King, Irena B; Metzgar, Jordan S

    2009-01-01

    Background: The nitrogen isotope ratio (expressed as δ15N) of red blood cells (RBCs) is highly correlated with the RBC long-chain ω−3 (n−3) fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in Yup'ik Eskimos. Because δ15N can also be measured in hair samples, it could provide a noninvasive, retrospective biomarker for EPA and DHA intakes. Objectives: We investigated the agreement between δ15N in hair and RBCs and then evaluated the relations between hair δ15N and RBC EPA and DHA. We also assessed the agreement in carbon isotope ratios (δ13C) between hair and RBCs, because δ13C has been proposed as a dietary biomarker in other populations. Design: We assessed relations between hair and RBC δ15N and δ13C in a community-based sample of 144 Yup'ik Eskimos and examined the correlations between δ15N and RBC EPA and DHA in a subset of these participants (n = 44). Results: We showed a 1:1 relation with good agreement between hair and RBC δ15N (r = 0.91) and δ13C (r = 0.87). Hair isotope ratios were greater than RBC ratios by 1.5‰ for δ15N and by 2.3‰ for δ13C. There were strong correlations between hair δ15N and RBC EPA and DHA (r = 0.83 and 0.84, respectively). Conclusions: These results support the use of hair δ15N values as a biomarker of EPA and DHA intakes. Because hair collection is noninvasive and the samples require no special processing, studies of EPA and DHA intakes in large populations could use biomarkers rather than self-reports to assess these fatty acids. PMID:19864410

  7. Effects of the Dietary ω3:ω6 Fatty Acid Ratio on Body Fat and Inflammation in Zebrafish (Danio rerio)

    PubMed Central

    Powell, Mickie L; Pegues, Melissa A; Szalai, Alexander J; Ghanta, Vithal K; D'Abramo, Louis R; Watts, Stephen A

    2015-01-01

    The diets of populations in industrialized nations have shifted to dramatically increased consumption of ω6 polyunsaturated fatty acids (PUFA), with a corresponding decrease in the consumption of ω3 PUFA. This dietary shift may be related to observed increases in obesity, chronic inflammation, and comorbidities in the human population. We examined the effects of ω3:ω6 fatty acid ratios in the context of constant total dietary lipid on the growth, total body fat, and responses of key inflammatory markers in adult zebrafish (Danio rerio). Zebrafish were fed diets in which the ω3:ω6 PUFA ratios were representative of those in a purported ancestral diet (1:2) and more contemporary Western diets (1:5 and 1:8). After 5 mo, weight gain (fat free mass) of zebrafish was highest for those that received the 1:8 ratio treatment, but total body fat was lowest at this ratio. Measured by quantitative real-time RT–PCR, mRNA levels from liver samples of 3 chronic inflammatory response genes (C-reactive protein, serum amyloid A, and vitellogenin) were lowest at the 1:8 ratio. These data provide evidence of the ability to alter zebrafish growth and body composition through the quality of dietary lipid and support the application of this model to investigations of human health and disease related to fat metabolism. PMID:26310458

  8. Raman and infrared spectroscopy study on structure and microstructure of glass-ceramic materials from SiO2-Al2O3-Na2O-K2O-CaO system modified by variable molar ratio of SiO2/Al2O3

    NASA Astrophysics Data System (ADS)

    Partyka, Janusz; Leśniak, Magdalena

    2016-01-01

    This paper is focused on the effect of the molar ratio of SiO2/Al2O3 on the microstructure and structure of the internal aluminium-silicon-oxide lattice of the glass-ceramic materials from the SiO2-Al2O3-Na2O-K2O-CaO system. In order to examine the real composition of the obtained samples, a chemical analysis was performed. Following the heat-treatment procedure, pseudowollastonite, anorthite and the vitreous phase were identified. In order to determine the microstructure, research using the scanning electron microscope (SEM) with EDS was done. For the inner structural study, X-ray diffraction (XRD), Raman spectroscopy as well as MIR and FIR spectroscopy were performed.

  9. Raman and infrared spectroscopy study on structure and microstructure of glass-ceramic materials from SiO2-Al2O3-Na2O-K2O-CaO system modified by variable molar ratio of SiO2/Al2O3.

    PubMed

    Partyka, Janusz; Leśniak, Magdalena

    2016-01-01

    This paper is focused on the effect of the molar ratio of SiO2/Al2O3 on the microstructure and structure of the internal aluminium-silicon-oxide lattice of the glass-ceramic materials from the SiO2-Al2O3-Na2O-K2O-CaO system. In order to examine the real composition of the obtained samples, a chemical analysis was performed. Following the heat-treatment procedure, pseudowollastonite, anorthite and the vitreous phase were identified. In order to determine the microstructure, research using the scanning electron microscope (SEM) with EDS was done. For the inner structural study, X-ray diffraction (XRD), Raman spectroscopy as well as MIR and FIR spectroscopy were performed. PMID:26196934

  10. Derivative-ratio spectrophotometric method for the determination of ternary mixture of aspirin, paracetamol and salicylic acid

    NASA Astrophysics Data System (ADS)

    El-Yazbi, Fawzi A.; Hammud, Hassan H.; Assi, Sulaf A.

    2007-10-01

    A derivative spectrophotometric method was developed for the assay of a ternary mixture of aspirin (ASP), paracetamol (PAR) and salicylic acid (SAL). The method is based on the use of the first and second derivatives of the ratio spectra and measurement at zero-crossing wavelengths. The ratio spectra were obtained by dividing the absorption spectrum of the mixture by that of one of the components. The concentration of the other components are then determined from their respective calibration curves treated similarly. The described method was applied for the determination of these combinations in synthetic mixtures and dosage forms. The results obtained were accurate and precise.

  11. [Headgear-free molar distalization].

    PubMed

    Manhartsberger, C

    1994-12-01

    The difficulty in treating dentoalveolar class II disharmonies is briefly outlined. An innovative treatment method is presented which makes possible a distalization without the use of headgear. In the treatment method bands are cemented on the first molars, next impressions are made of the upper and lower dental arch, and then the impressions are poured with plaster. Following this the models are mounted in centric relationship in an articulator and the bite is opened 2 mm to 3 mm, so that the molars can be moved without making occlusal contact. The apparatus, an acrylic splint, is constructed in such a fashion as to cover the palatal surfaces from 2nd premolar to 2nd premolar. In addition, the premolars are also covered occlusally and buccally and the canine tips and the incisal edges are covered labially. A headgear tube is attached at the buccal surface in the premolar region of the acrylic splint. This acrylic splint, which is itself retentive, is cemented using glass ionomer cement. Combining this apparatus with a modified Nance Button makes it possible to establish an anchoring segment which is able to retain its position in the face of molar distalization. Molar distalization is then performed using a 0.032 inch stainless steel wire, which is placed between the headgear tube of the acrylic splint and the headgear tube of the band of the first molar. Highly elastic nickel-titanium open coil springs are used as the force elements. PMID:7851830

  12. Effects of Prenatal Social Stress and Maternal Dietary Fatty Acid Ratio on Infant Temperament: Does Race Matter?

    PubMed Central

    Brunst, Kelly J.; Enlow, Michelle Bosquet; Kannan, Srimathi; Carroll, Kecia N.; Coull, Brent A.; Wright, Rosalind J.

    2014-01-01

    Background Infant temperament predicts a range of developmental and behavioral outcomes throughout childhood. Both maternal fatty acid intake and psychosocial stress exposures during pregnancy may influence infant temperament. Furthermore, maternal race may modify prenatal diet and stress effects. The goals of this study are to examine the joint effects of prenatal diet and stress and the modifying effects of race on infant behavior. Methods Analyses included N=255 mother-infant dyads, primarily minorities (21% Blacks; 42% Hispanics), enrolled in an urban pregnancy cohort. Maternal prenatal stress was indexed by a negative life events (NLEs) score on the Crisis in Family Systems-Revised survey. Prenatal total daily intakes of polyunsaturated fatty acids (PUFAs) (n3, n6) were estimated from a food frequency questionnaire; n3:n6 ratios were calculated. Mothers completed the Infant Behavior Questionnaire-Revised (IBQ-R), a measure of infant temperament, when the children were 6 months old. Three commonly used dimensions were derived: Orienting & Regulation, Extraversion, and Negative Affectivity. Associations among prenatal stress, maternal n3:n6 ratio, and race/ethnicity on infant temperament, controlling for maternal education and age and child sex, were examined. Results Among Blacks, prenatal stress effects on infant Orienting & Regulation scores were modified by maternal n3:n6 ratios (p=0.03): As NLEs increased, lower n3:n6 ratios predicted lower infant Orienting & Regulation scores, whereas higher n3:n6 ratios attenuated the effect of prenatal stress. There were no main or interaction effects predicting Extraversion or Negative Affectivity. Conclusions An optimal PUFA ratio may protect the fetus from stress effects on infant behavior, particularly among Blacks. These findings may have implications for later neurodevelopment and social functioning predicted by early temperamental characteristics. PMID:25328835

  13. Fractionation of the stable carbon isotope ratio of essential fatty acids in zebrafish Danio rerio and mud snails Bellamya chinensis.

    PubMed

    Fujibayashi, Megumu; Ogino, Masahiro; Nishimura, Osamu

    2016-02-01

    Fractionation of stable carbon (C) isotopes in the essential fatty acids 18:2n-6, 18:3n-3, 20:4n-6, 20:5n-3, and 22:6n-3 was investigated in the zebrafish Danio rerio and the mud snail Bellamya chinensis fed the same two diets. These diets differed in essential fatty acid compositions: (1) TetraMin contained all five fatty acids, and (2) Chlorella contained only two, 18:2n-6 and 18:3n-3. On average, the isotopic fractionation was -0.5 ± 0.9 ‰ for 18:2n-6 and 18:3n-3 for all experiments, indicating that the fractionation of these essential fatty acids was negligible. However, the isotopic fractionation of 20:4n-6, 20:5n-3, and 22:6n-3 varied greatly between species and between diets. The isotopic fractionation of the Chlorella diet was -0.2 and -6.9 ‰ for zebrafish and mud snail, but 4.2 and -1.3 ‰, respectively, when these consumers were fed TetraMin. This variation could be explained by the different amount of assimilation and the biosynthesis of these fatty acids from their precursors (i.e., 18:2n-6 and 18:3n-3). These results indicate that the isotopic composition of C20 and C22 essential fatty acids was strongly influenced by the fatty acid composition in the diets. Thus the stable C isotope ratios of C18 essential fatty acids in consumers are more useful as dietary tracers in food web studies. PMID:26537876

  14. Sex Differences in the Association between the Eicosapentaenoic Acid/Arachidonic Acid Ratio and the Visceral Fat Area among Patients with Type 2 Diabetes.

    PubMed

    Nakanishi, Shuhei; Nagano, Chihiro; Miyahara, Mitsue; Sawano, Fumio

    2016-01-01

    Objective To examine the serum levels of eicosapentaenoic acid (EPA) and the ratios of docosahexaenoic acid (DHA), and the EPA/arachidonic acid (AA) and DHA/AA and to clarify their association with the areas of subcutaneous and visceral fat separately by sex among patients with type 2 diabetes. Methods The study participants included 118 men and 96 women who were hospitalized to receive treatment for type 2 diabetes. We examined the serum levels of EPA and DHA and the ratios of EPA/AA and DHA/AA, and analyzed their association with the total fat area (TFA), subcutaneous fat area (SFA), and visceral fat area (VFA), as measured by computed tomography. Results The mean age of the study participants was 62.6±13.6 years. The mean HbA1c level was 9.37±2.27%. Among men, a multivariate regression analysis adjusted for age and BMI, revealed a significant negative association between VFA and the EPA/AA ratio. When the multivariate regression analysis was adjusted for age, BMI, and HbA1c level, VFA was still found to be significantly negatively associated with the EPA/AA ratio. Although a crude analysis revealed a significant negative association between SFA and the EPA/AA ratio in women, no association was observed in multivariate regression analyses. Conclusion These results suggest the possibility that EPA inhibits the accumulation of visceral fat in men. Furthermore, there appear to be marked differences in the relationships between EPA and DHA and visceral fat accumulation. PMID:27181531

  15. Lactate and the Lactate-to-Pyruvate Molar Ratio Cannot Be Used as Independent Biomarkers for Monitoring Brain Energetic Metabolism: A Microdialysis Study in Patients with Traumatic Brain Injuries

    PubMed Central

    Sahuquillo, Juan; Merino, Maria-Angels; Sánchez-Guerrero, Angela; Arikan, Fuat; Vidal-Jorge, Marian; Martínez-Valverde, Tamara; Rey, Anna; Riveiro, Marilyn; Poca, Maria-Antonia

    2014-01-01

    Background For decades, lactate has been considered an excellent biomarker for oxygen limitation and therefore of organ ischemia. The aim of the present study was to evaluate the frequency of increased brain lactate levels and the LP ratio (LPR) in a cohort of patients with severe or moderate traumatic brain injury (TBI) subjected to brain microdialysis monitoring to analyze the agreement between these two biomarkers and to indicate brain energy metabolism dysfunction. Methods Forty-six patients with an admission Glasgow coma scale score of ≤13 after resuscitation admitted to a dedicated 10-bed Neurotraumatology Intensive Care Unit were included, and 5305 verified samples of good microdialysis data were analyzed. Results Lactate levels were above 2.5 mmol/L in 56.9% of the samples. The relationships between lactate and the LPR could not be adequately modeled by any linear or non-linear model. Neither Cohen’s kappa nor Gwet’s statistic showed an acceptable agreement between both biomarkers to classify the samples in regard to normal or abnormal metabolism. The dataset was divided into four patterns defined by the lactate concentrations and the LPR. A potential interpretation for these patterns is suggested and discussed. Pattern 4 (low pyruvate levels) was found in 10.7% of the samples and was characterized by a significantly low concentration of brain glucose compared with the other groups. Conclusions Our study shows that metabolic abnormalities are frequent in the macroscopically normal brain in patients with traumatic brain injuries and a very poor agreement between lactate and the LPR when classifying metabolism. The concentration of lactate in the dialysates must be interpreted while taking into consideration the LPR to distinguish between anaerobic metabolism and aerobic hyperglycolysis. PMID:25025772

  16. Dietary methionine and n-6/n-3 polyunsaturated fatty acid ratio reduce adverse effects of infectious bursal disease in broilers.

    PubMed

    Maroufyan, E; Kasim, A; Ebrahimi, M; Loh, T C; Hair-Bejo, M; Soleimani, A F

    2012-09-01

    This study was carried out to investigate the modulatory effects of dietary methionine and n-6/n-3 polyunsaturated fatty acids (PUFA) ratio on immune response and performance of infectious bursal disease (IBD)-challenged broiler chickens. In total, 350 one-day-old male broiler chicks were assigned to 1 of the 6 dietary treatment groups in a 3 × 2 factorial arrangement. There were 3 n-6/n-3 PUFA ratios (45, 5.5, and 1.5) and 2 levels of methionine (NRC recommendation and twice NRC recommendation). The results showed that birds fed with dietary n-6/n-3 PUFA ratio of 5.5 had higher BW, lower feed intake, and superior FCR than other groups. However, the highest antibody response was observed in birds with dietary n-6/n-3 PUFA ratio of 1.5. Lowering n-6/n-3 PUFA ratio reduced bursa lesion score equally in birds fed with n-6/n-3 PUFA ratio of 5.5 and 1.5. Supplementation of methionine by twice the recommendation also improved FCR and reduced feed intake and bursa lesion score. However, in this study, the optimum performance (as measured by BW, feed intake, and FCR) did not coincide with the optimum immune response (as measured by antibody titer). It seems that dietary n-3 PUFA modulates the broiler chicken performance and immune response in a dose-dependent but nonlinear manner. Therefore, it can be suggested that a balance of moderate level of dietary n-6/n-3 PUFA ratio (5.5) and methionine level (twice recommendation) might enhance immune response together with performance in IBD-challenged broiler chickens. PMID:22912451

  17. Influence of temperature, time, liquid/solid ratio and sulfuric acid concentration on the hydrolysis of palm empty fruit bunches.

    PubMed

    Ferrer, Ana; Requejo, Ana; Rodríguez, Alejandro; Jiménez, Luis

    2013-02-01

    The influence of temperature (150-190 °C), time (0-20 min), liquid/solid ratio (6-8) and sulfuric acid concentration (0.1-0.5%), on the hydrolysis of palm empty fruit bunches (EFBs) was studied and the liquid and solid fractions were analyzed. Polynomial models were found to reproduce the experimental results with errors less than 15% in most of the cases (except for xylose concentration). Operating conditions of 190 °C for 15 min at a liquid/solid ratio of 6 and a sulfuric acid concentration of 0.1% resulted in the production of 3.12, 4.0, 2.35 and 2.28 g/L of glucose, xylose, arabinose and acetic acid, respectively, starting with 1000 g of EFBs. The yield was 67.96%. Soda-anthraquinone, ethanol and ethanolamine pulping of the solid fraction provided pulps with brightness values (63.24%, 28.78%, 48.76%), but with poor resistance properties (6.57-8.54 Nm/g for tensile index, 0.38-0.44 k N/g for burst index and 0.96-1.02 mN m2/g for tear index). Therefore it is advisable to use the pulps for speciality papers or for bioethanol-production. PMID:23266852

  18. Complications after third molar surgery.

    PubMed

    Pitekova, L; Satko, I; Novotnakova, D

    2010-01-01

    The authors describe the incidence of postoperative complications after the surgical removal of third molars, most common postoperative complications and their symptoms as well as risk factors leading to greater incidence of postoperative complications (Ref. 17). Full Text (Free, PDF) www.bmj.sk. PMID:20568422

  19. Nitric acid oxide mixing ratio measurements using a rocket launched chemiluminescent instrument

    NASA Technical Reports Server (NTRS)

    Horvath, Jack J.

    1989-01-01

    A total of 18 rocket launched parachute borne nitric oxide instruments were launched from 1977 to 1985. A very precise instrument for the measurement of the nitric oxide mixing ratio was fabricated. No changes were made in the main body of the instruments, i.e., things associated with the reaction volume. Except for the last 4 launches, however, it did not yield the required absolute values that was hoped for. Two major problems were encountered. First, the wrong choice of the background calibration gas, nitrogen, caused the first 10 data sets to be too low in the absolute mixing ratio by nearly the order of 2 to 5 ppbv. The error was realized, and air was substituted for the bias gas measurement. Second, in the desire to extend the measurement to higher altitudes, the problem of contaminating the inlet flow tube with ozone from the reagent gas was encountered. The ozone valve was opened too early in the flight and this caused the pressure in the reaction volume to exceed the pressure at the flow tube entrance, permitting the ozone to migrate backwards. This problem was restricted to an altitude above 45 km.

  20. Partial molar volume of L-Valine in water under high pressure

    NASA Astrophysics Data System (ADS)

    Sawamura, Seiji

    2013-06-01

    Partial molar volume of L-valine in water was estimated up to 400 MPa from pressure coefficient of the solubility of the solute and molar volume of solid valine. The former was measured in a previous paper and the latter was measured in this article using a piston-cylinder typed cell. The partial molar volume increased with pressure and a maximum was observed around 250 MPa. It was compared with other amino acids.

  1. Amino acid composition of humic substances in tundra soils

    NASA Astrophysics Data System (ADS)

    Vasilevich, R. S.; Beznosikov, V. A.

    2015-06-01

    Peripheral amino acid fragments of humic and fulvic acid molecules from tundra soils have been identified and quantified. A significant weight fraction of amino acids has been found in humic acid preparations, which exceeds their content in fulvic acids. Features of the amino acid composition of humic substances along the soil profile and depending on the degree of hydromorphism and the proportions of different (neutral, basic, acidic, cyclic) groups in amino acids have been revealed. The molar ratio between the hydroxy and heterocyclic amino acids reflects the degree of humification of the soil.

  2. Lower ω-6/ω-3 Polyunsaturated Fatty Acid Ratios Decrease Fat Deposition by Inhibiting Fat Synthesis in Gosling.

    PubMed

    Yu, Lihuai; Wang, Shunan; Ding, Luoyang; Liang, Xianghuan; Wang, Mengzhi; Dong, Li; Wang, Hongrong

    2016-10-01

    The objective of the current study was to investigate the effects of dietary ω-6/ω-3 polyunsaturated fatty acid (PUFA) ratios on lipid metabolism in goslings. One hundred and sixty 21-day-old Yangzhou geese of similar weight were randomly divided into 4 groups. They were fed different PUFA-supplemented diets (the 4 diets had ω-6/ω-3 PUFA ratios of 12:1, 9:1, 6:1, or 3:1). The geese were slaughtered and samples of liver and muscle were collected at day 70. The activities and the gene expression of enzymes involved in lipid metabolism were measured. The results show that the activities of acetyl coenzyme A carboxylase (ACC), malic enzyme (ME), and fatty acid synthase (FAS) were lower (p<0.05), but the activities of hepatic lipase (HL) and lipoprotein lipase (LPL) were higher (p<0.05), in the liver and the muscle from the 3:1 and 6:1 groups compared with those in the 9:1 and 12:1 groups. Expression of the genes for FAS (p<0.01), ME (p<0.01) and ACC (p<0.05) were higher in the muscle of groups fed diets with higher ω-6/ω-3 PUFA ratios. Additionally, in situ hybridization tests showed that the expression intensities of the high density lipoprotein (HDL-R) gene in the 12:1 and 9:1 groups were significantly lower (p<0.01) than that of the 3:1 group in the muscle of goslings. In conclusion, diets containing lower ω-6/ω-3 PUFA ratios (3:1 or 6:1) could decrease fat deposition by inhibiting fat synthesis in goslings. PMID:27189638

  3. Hydrogen isotope ratios of palmitic acid in lacustrine sediments record late Quaternary climate variations

    NASA Astrophysics Data System (ADS)

    Huang, Yongsong; Shuman, Bryan; Wang, Yi; Webb, Thompson, III

    2002-12-01

    The rich paleoclimate information preserved in lacustrine sedimentary organic matter can be difficult to extract because of the mixed terrestrial and aquatic inputs. Herein we demonstrate that compound-specific hydrogen isotope analysis of palmitic acid, (PA), a ubiquitous compound in lacustrine sediments, captures the δD signals of lake water. Samples collected across a diverse range of 33 North American lakes show a strong correlation between water and δDPA values. At Crooked Pond, Massachusetts, the δDPA changes in a 14 k.y. sediment record parallel temperature trends inferred from fossil pollen. Downcore changes reveal differences between climatic trends in New England and in Greenland that are consistent with important regional differences in climate controls.

  4. Effect of Ce/Zr molar ratio on the performance of Cu–Ce{sub x}–Zr{sub 1−x}/TiO{sub 2} catalyst for selective catalytic reduction of NO{sub x} with NH{sub 3} in diesel exhaust

    SciTech Connect

    Sun, Xiaoliang; Gong, Cairong; Lv, Gang; Bin, Feng; Song, Chonglin

    2014-12-15

    Graphical abstract: The Cu–Ce{sub 0.25}–Zr{sub 0.75}/TiO{sub 2} catalyst exhibited excellent SCR activity at 165–450 °C within the range of exhaust temperatures of diesel engines. - Highlights: • Cu–Ce{sub x}–Zr{sub 1−x}/TiO{sub 2} catalysts were prepared by a wet impregnation method. • The property for NH{sub 3}-selective catalytic reduction of NO{sub x} were investigated. • The Ce/Zr molar ratio had effects on the performance of Cu–Ce–Zr/TiO{sub 2} catalysts. • The Cu–Ce{sub 0.25}–Zr{sub 0.75}/TiO{sub 2} sample exhibited 100% NO{sub x} conversion between 165 °C and 450 °C. • The factors that govern the activity enhancement were extensively investigated. - Abstract: Copper–cerium–zirconium catalysts loaded on TiO{sub 2} prepared by a wet impregnation method were investigated for NH{sub 3}-selective catalytic reduction of NO{sub x}, aiming to study the effects of the Ce/Zr molar ratio on the performance of Cu–Ce–Zr/TiO{sub 2} catalysts. The Cu–Ce{sub 0.25}–Zr{sub 0.75}/TiO{sub 2} sample exhibited nearly 100% NO{sub x} conversion over a wide temperature range (165–450 °C), which is strikingly superior to that of Cu/TiO{sub 2} (210–389 °C) within the range of exhaust temperatures of diesel engines. The factors that govern the activity enhancement were extensively investigated by using a series of characterization techniques, namely X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction by hydrogen (H{sub 2}-TPR). The results showed that the addition of zirconium and/or cerium refined the copper dispersion, prevented copper crystallization and partially incorporated the copper ions into the zirconia (ceira) lattice, which led to enhance the redox abilities of Cu–Ce–Zr/TiO{sub 2} catalysts.

  5. ACID GAS REMOVAL CHARACTERISTICS OF CORONA RADICAL SHOWER SYSTEM FOR A TREATMENT OF STATIONARY ENGINE FLUE GAS

    EPA Science Inventory

    Acid gas removal experiments are carried out in large bench scale corona radical shower reactor. A simulated engine flue gas is air mixed with NO, SO2 and CH4. Optimums for acid gas removal rate have been conducted in terms of the ammonia to acid gas molar ratio, the applied volt...

  6. Anomalous HNO3/NO(x) ratio of remote tropospheric air: Conversion of nitric acid to formic acid and NO(x)?

    NASA Technical Reports Server (NTRS)

    Chatfield, Robert B.

    1994-01-01

    The N oxidation ratio, (HNO3)/(NO(x)), in the free troposphere is measured at approx. 1 to 9 (averaging approx. 5), consistently lower than the values of 15-100 which known theory suggests to be reached rapidly. This discrepancy casts doubt on current models' abilities to predict effects of NO sources on remote (NO), and so also (O3) and (OH). HNO3-to-NO(x) recycling processes involving HCHO in solution are appealing explanations for the ratio. Known chemical theory are illustrated using a Lagrangian box model of the mid-troposphere which simulates characteristic episodes form NO(x) input to HNO3 washout. Ratio and budget constraint equations for No(y) can usefully restrict conceivable explanations of missing chemistry of fast nitrogen cycling; most explanations could be called 'fast-cycles' or 're-NO(x)-ification.' These equations also show how current global models may suggest spuriously good N oxidation ratios and errors in OH. Aerosol or cloud droplets reactions with HCHO may produce (a) formic acid (which needs an appropriate source) and NO(x), or alternatively, (b) hydroxymethyl nitrate (or methyl dinitrate), which might supply a large, variable amount of 'missing NO(y) not currently measurable except by NO(y) instruments.

  7. EFFECTS OF NITRIC ACID ON CRITICALITY SAFETY ANALYSIS

    SciTech Connect

    Williamson, B.

    2011-08-18

    As nitric acid molarity is increased, there are two competing phenomena affecting the reactivity of the system. First, there is interaction between each of the 10 wells in the basket-like insert. As the molarity of the nitric acid solution is increased (it moves from 100% water to 100% HNO{sub 3}), the hydrogen atom density decreases by about 80%. However, it remains a relatively efficient moderator. The moderating ratio of nitric acid is about 90% that of water. As the media between the wells is changed from 100% water to 100% nitric acid, the density of the media increases by 50%. A higher density typically leads to a better reflector. However, when the macroscopic scattering cross sections are considered, nitric acid is a much worse reflector than water. The effectiveness of nitric acid as a reflector is about 40% that of water. Since the media between the wells become a worse reflector and still remains an effective moderator, interaction between the wells increases. This phenomenon will cause reactivity to increase as nitric acid molarity increases. The seond phenomenon is due to the moderating ratio changing in the high concentration fissile-nitric acid solution in the 10 wells. Since the wells contain relatively small volumes of high concentration solutions, a small decrease in moderating power has a large effect on reactivity. This is due to the fact that neutrons are more likely to escape the high concentration fissile solution before causing another fission event. The result of this phenomenon is that as nitric acid molarity increases, reactivity decreases. Recent studies have shown that the second phenomenon is indeed the dominating force in determining reactivity changes in relation to nitric acid molarity changes. When considering the system as a whole, as nitric acid molarity increases, reactivity decreases.

  8. Effects of dietary ratio of n-6 to n-3 polyunsaturated fatty acids on immunoglobulins, cytokines, fatty acid composition, and performance of lactating sows and suckling piglets

    PubMed Central

    2012-01-01

    This experiment was conducted to investigate the effects of dietary ratios of n-6:n-3 polyunsaturated fatty acids (PUFA) on the performance of lactating sows and their piglets. Thirty pregnant Landrace sows were assigned to one of three treatments from d 108 of gestation until weaning (26–29 d) and were fed diets containing different ratios of n-6:n-3 PUFA including 3:1, 9:1 and 13:1. The effects on sow and litter production traits were examined together with an assessment of sow body condition. No differences were detected among the treatments for the daily feed intake of sows or changes in sow weight and back-fat levels during lactation (P > 0.05). Litter size at d 14 and d 21 were tended to increase in 3:1 treatment compared with 9:1 and 13:1 treatments (P < 0.10). Litter weight gain (1.77 kg/d) from d 0 to d 14 was tended to increase in 9:1 groups compared with the other two treatments (P < 0.10). A significant difference was observed for the content of α -linolenic acid, total n-3 PUFA, and the ratio of n-6:n-3 PUFA in the colostrum, milk, and piglets plasma (P < 0.01). The effects of different ratios of n-6:n-3 PUFA in sow diets on colostrum, milk, and piglet plasma immunoglobulin concentrations are studied. No difference was observed among treatments in the concentrations of IgM, and IgA in colostrum (P > 0.05). A great significant difference for IgG concentration was observed among 3 group in colostrum. A great significant difference for IgA, and IgM (P < 0.01) concentrations in piglet plasma at d14 and a significant difference for IgG(P < 0.05) was observed at d14. Furthermore, at d 21 of lactation, piglet plasma IgG and IgA concentration were greater in 3:1 compared with 13:1 group (P < 0.01). In summary, the current study demonstrated that altering the ratio of n-6:n-3 PUFA in lactating sow diet had an effect on the immune component including immunoglobulin and cytokines, and it tended to increase the litter average

  9. [Studies on the effects of carbon:nitrogen ratio, inoculum type and yeast extract addition on jasmonic acid production by Botryodiplodia theobromae Pat. strain RC1].

    PubMed

    Eng Sánchez, Felipe; Gutiérrez-Rojas, Mariano; Favela-Torres, Ernesto

    2008-09-30

    Jasmonic acid is a native plant growth regulator produced by algae, microorganisms and higher plants. This regulator is involved in the activation of defence mechanisms against pathogens and wounding in plants. Studies concerning the effects of carbon: nitrogen ratio (C/Nr: 17, 35 and 70), type of inoculum (spores or mycelium) and the yeast extract addition in the media on jasmonic acid production by Botryodiplodia theobromae were evaluated. Jasmonic acid production was stimulated at the carbon: nitrogen ratio of 17. Jasmonic acid productivity was higher in the media inoculated with mycelium and in the media with yeast extract 1.7 and 1.3 times, respectively. PMID:18785793

  10. Acid Mine Drainage Passive Remediation: Potential Use of Alkaline Clay, Optimal Mixing Ratio and Long Term Impacts

    NASA Astrophysics Data System (ADS)

    Plaza, F.; Liang, X.; Wen, Y.; Perone, H.

    2015-12-01

    Acid mine drainage (AMD) is one of the most adverse environmental problems of the mine industry. Surface water and ground water affected by this pollution are characterized by their acidity and the high content of sulfates and heavy metals. In this study, alkaline clay, an industrial waste with a high pH, which is utilized in the alumina refining process, was used as the remediation material to inhibit pyrite oxidation. Through a series of batch and column experiments, complemented with field measurements and geochemical modeling, three important issues associated with this passive and auto sustainable acid mine drainage remediation method were investigated: 1) the potential use of alkaline clay as an AMD remediation material, 2) the adequate alkaline clay/coal refuse mixing ratio (AC/CR) to ensure pH values near to neutral conditions, and, 3) the prediction of long term impacts, in terms of the trends of the main parameters involved in this process such as pH, concentrations of sulfate, iron and other dissolved contaminants. Both field measurements and the samples used for the experiments came from a coal waste site located in Mather, Pennsylvania. Alkaline clay proved to be an effective remediation material for AMD. It was found that 10% AC/CR is an adequate mixing ratio (i.e. the upper limit), which has been also indicated by field measurements. The concentrations of some contaminants such as iron, manganese or sulfate are significantly reduced with the remediation approach, compared to those representative concentrations found in mine tailings. Moreover, results suggest a very reliable long-term stability of the remediation (i.e. neutral pH conditions are maintained), thus enhancing the generation of iron precipitates that could produce pyrite grain coating and hardpan (i.e. cemented layer) on the surface. These processes also made the amended layer less porous, thus increasing water retention and hindering oxygen diffusion.

  11. Fracture behavior of human molars.

    PubMed

    Keown, Amanda J; Lee, James J-W; Bush, Mark B

    2012-12-01

    Despite the durability of human teeth, which are able to withstand repeated loading while maintaining form and function, they are still susceptible to fracture. We focus here on longitudinal fracture in molar teeth-channel-like cracks that run along the enamel sidewall of the tooth between the gum line (cemento-enamel junction-CEJ) and the occlusal surface. Such fractures can often be painful and necessitate costly restorative work. The following study describes fracture experiments made on molar teeth of humans in which the molars are placed under axial compressive load using a hard indenting plate in order to induce longitudinal cracks in the enamel. Observed damage modes include fractures originating in the occlusal region ('radial-median cracks') and fractures emanating from the margin of the enamel in the region of the CEJ ('margin cracks'), as well as 'spalling' of enamel (the linking of longitudinal cracks). The loading conditions that govern fracture behavior in enamel are reported and observations made of the evolution of fracture as the load is increased. Relatively low loads were required to induce observable crack initiation-approximately 100 N for radial-median cracks and 200 N for margin cracks-both of which are less than the reported maximum biting force on a single molar tooth of several hundred Newtons. Unstable crack growth was observed to take place soon after and occurred at loads lower than those calculated by the current fracture models. Multiple cracks were observed on a single cusp, their interactions influencing crack growth behavior. The majority of the teeth tested in this study were noted to exhibit margin cracks prior to compression testing, which were apparently formed during the functional lifetime of the tooth. Such teeth were still able to withstand additional loading prior to catastrophic fracture, highlighting the remarkable damage containment capabilities of the natural tooth structure. PMID:22956116

  12. Impact of hydrolysis conditions on the detection of mannuronic to guluronic acid ratio in alginate and its derivatives.

    PubMed

    Lu, Jiaojiao; Yang, Hai; Hao, Jie; Wu, Chengling; Liu, Li; Xu, Naiyu; Linhardt, Robert J; Zhang, Zhenqing

    2015-05-20

    Alginate is a linear and acidic polysaccharide, composed of (1 → 4) linked β-D-mannuronic acid (ManA) and α-L-guluronic acid (GulA). The ratio of ManA to GulA (M/G) is one of the most important factors for the application of alginate and its derivatives in various areas. In this work, a robust and accurate method was developed to analyze M/G using high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). The impact of hydrolysis conditions on the release patterns of ManA and GulA from alginate and its derivatives was investigated. The release patterns of ManA and GulA need to be considered separately to obtain an accurate M/G. Several hydrolysis conditions were established that released ManA and GulA completely and maintained these saccharide residues intact. The proper M/G of alginates from different sources and its derivatives could then be calculated by integration of the corresponding ManA and GulA peaks. PMID:25817657

  13. Mandibular lip bumper for molar torque control.

    PubMed

    Celentano, Giuseppe; Longobardi, Annalisa; Cannavale, Rosangela; Perillo, Letizia

    2011-01-01

    Treatment effects of lip bumpers alone include flaring of the mandibular incisors, distalization and uprighting of the mandibular first molars, and buccal expansion of the canines, premolars, and molar. Lip forces are transmitted through this appliance onto the molars. Moreover the lip bumper is able to derotate, expand or constrict, upright and reinforce the anchorage whereas torque control is lacking. Aim of this paper is the presentation of a new type of lip bumper that allows the molar torque control. PMID:21515237

  14. Retention Mechanisms of Citric Acid in Ternary Kaolinite-Fe(III)-Citrate Acid Systems Using Fe K-edge EXAFS and L3,2-edge XANES Spectroscopy

    NASA Astrophysics Data System (ADS)

    Yang, Jianjun; Wang, Jian; Pan, Weinan; Regier, Tom; Hu, Yongfeng; Rumpel, Cornelia; Bolan, Nanthi; Sparks, Donald

    2016-05-01

    Organic carbon (OC) stability in tropical soils is strongly interlinked with multivalent cation interaction and mineral association. Low molecular weight organic acids (LMWOAs) represent the readily biodegradable OC. Therefore, investigating retention mechanisms of LMWOAs in mineral-cation-LMWOAs systems is critical to understanding soil C cycling. Given the general acidic conditions and dominance of kaolinite in tropical soils, we investigated the retention mechanisms of citric acid (CA) in kaolinite-Fe(III)-CA systems with various Fe/CA molar ratios at pH ~3.5 using Fe K-edge EXAFS and L3,2-edge XANES techniques. With Fe/CA molar ratios >2, the formed ferrihydrite mainly contributed to CA retention through adsorption and/or coprecipitation. With Fe/CA molar ratios from 2 to 0.5, ternary complexation of CA to kaolinite via a five-coordinated Fe(III) bridge retained higher CA than ferrihydrite-induced adsorption and/or coprecipitation. With Fe/CA molar ratios ≤0.5, kaolinite-Fe(III)-citrate complexation preferentially occurred, but less CA was retained than via outer-sphere kaolinite-CA complexation. This study highlighted the significant impact of varied Fe/CA molar ratios on CA retention mechanisms in kaolinite-Fe(III)-CA systems under acidic conditions, and clearly showed the important contribution of Fe-bridged ternary complexation on CA retention. These findings will enhance our understanding of the dynamics of CA and other LMWOAs in tropical soils.

  15. Retention Mechanisms of Citric Acid in Ternary Kaolinite-Fe(III)-Citrate Acid Systems Using Fe K-edge EXAFS and L3,2-edge XANES Spectroscopy.

    PubMed

    Yang, Jianjun; Wang, Jian; Pan, Weinan; Regier, Tom; Hu, Yongfeng; Rumpel, Cornelia; Bolan, Nanthi; Sparks, Donald

    2016-01-01

    Organic carbon (OC) stability in tropical soils is strongly interlinked with multivalent cation interaction and mineral association. Low molecular weight organic acids (LMWOAs) represent the readily biodegradable OC. Therefore, investigating retention mechanisms of LMWOAs in mineral-cation-LMWOAs systems is critical to understanding soil C cycling. Given the general acidic conditions and dominance of kaolinite in tropical soils, we investigated the retention mechanisms of citric acid (CA) in kaolinite-Fe(III)-CA systems with various Fe/CA molar ratios at pH ~3.5 using Fe K-edge EXAFS and L3,2-edge XANES techniques. With Fe/CA molar ratios >2, the formed ferrihydrite mainly contributed to CA retention through adsorption and/or coprecipitation. With Fe/CA molar ratios from 2 to 0.5, ternary complexation of CA to kaolinite via a five-coordinated Fe(III) bridge retained higher CA than ferrihydrite-induced adsorption and/or coprecipitation. With Fe/CA molar ratios ≤0.5, kaolinite-Fe(III)-citrate complexation preferentially occurred, but less CA was retained than via outer-sphere kaolinite-CA complexation. This study highlighted the significant impact of varied Fe/CA molar ratios on CA retention mechanisms in kaolinite-Fe(III)-CA systems under acidic conditions, and clearly showed the important contribution of Fe-bridged ternary complexation on CA retention. These findings will enhance our understanding of the dynamics of CA and other LMWOAs in tropical soils. PMID:27212680

  16. Retention Mechanisms of Citric Acid in Ternary Kaolinite-Fe(III)-Citrate Acid Systems Using Fe K-edge EXAFS and L3,2-edge XANES Spectroscopy

    PubMed Central

    Yang, Jianjun; Wang, Jian; Pan, Weinan; Regier, Tom; Hu, Yongfeng; Rumpel, Cornelia; Bolan, Nanthi; Sparks, Donald

    2016-01-01

    Organic carbon (OC) stability in tropical soils is strongly interlinked with multivalent cation interaction and mineral association. Low molecular weight organic acids (LMWOAs) represent the readily biodegradable OC. Therefore, investigating retention mechanisms of LMWOAs in mineral-cation-LMWOAs systems is critical to understanding soil C cycling. Given the general acidic conditions and dominance of kaolinite in tropical soils, we investigated the retention mechanisms of citric acid (CA) in kaolinite-Fe(III)-CA systems with various Fe/CA molar ratios at pH ~3.5 using Fe K-edge EXAFS and L3,2-edge XANES techniques. With Fe/CA molar ratios >2, the formed ferrihydrite mainly contributed to CA retention through adsorption and/or coprecipitation. With Fe/CA molar ratios from 2 to 0.5, ternary complexation of CA to kaolinite via a five-coordinated Fe(III) bridge retained higher CA than ferrihydrite-induced adsorption and/or coprecipitation. With Fe/CA molar ratios ≤0.5, kaolinite-Fe(III)-citrate complexation preferentially occurred, but less CA was retained than via outer-sphere kaolinite-CA complexation. This study highlighted the significant impact of varied Fe/CA molar ratios on CA retention mechanisms in kaolinite-Fe(III)-CA systems under acidic conditions, and clearly showed the important contribution of Fe-bridged ternary complexation on CA retention. These findings will enhance our understanding of the dynamics of CA and other LMWOAs in tropical soils. PMID:27212680

  17. [Distalization of the upper second molar: biomechanics].

    PubMed

    Castaldo, A

    1991-01-01

    The Author shows a system to dystalize the second upper molars and, if necessary, the third upper molars. This system, easy to be adapted, is made up by a palatal bar inserted between the first upper molars, by a sectional and a 100 grams precalibrated open Sentalloy coil spring used as an active force. PMID:1784296

  18. Molar versus as a paradigm clash.

    PubMed Central

    Baum, W M

    2001-01-01

    The molar view of behavior arose in response to the demonstrated inadequacy of explanations based on contiguity. Although Dinsmoor's (2001) modifications to two-factor theory render it irrefutable, a more basic criticism arises when we see that the molar and molecular views differ paradigmatically. The molar view has proven more productive. PMID:11453623

  19. Acute Administration of Branched-Chain Amino Acids Increases the Pro-BDNF/Total-BDNF Ratio in the Rat Brain.

    PubMed

    Scaini, Giselli; Morais, Meline O S; Furlanetto, Camila B; Kist, Luiza W; Pereira, Talita C B; Schuck, Patrícia F; Ferreira, Gustavo C; Pasquali, Matheus A B; Gelain, Daniel P; Moreira, José Cláudio F; Bogo, Maurício R; Streck, Emilio L

    2015-05-01

    Maple syrup urine disease (MSUD) is caused by an inborn error in metabolism resulting from a deficiency in the branched-chain α-keto acid dehydrogenase complex activity. This blockage leads to accumulation of the branched-chain amino acids (BCAA) leucine, isoleucine and valine, as well as their corresponding α-keto acids and α-hydroxy acids. High levels of BCAAs are associated with neurological dysfunction and the role of pro- and mature brain-derived neurotrophic factor (BDNF) in the neurological dysfunction of MSUD is still unclear. Thus, in the present study we investigated the effect of an acute BCAA pool administration on BDNF levels and on the pro-BDNF cleavage-related proteins S100A10 and tissue plasminogen activator (tPA) in rat brains. Our results demonstrated that acute Hyper-BCAA (H-BCAA) exposure during the early postnatal period increases pro-BDNF and total-BDNF levels in the hippocampus and striatum. Moreover, tPA levels were significantly decreased, without modifications in the tPA transcript levels in the hippocampus and striatum. On the other hand, the S100A10 mRNA and S100A10 protein levels were not changed in the hippocampus and striatum. In the 30-day-old rats, we observed increased pro-BDNF, total-BDNF and tPA levels only in the striatum, whereas the tPA and S100A10 mRNA expression and the immunocontent of S100A10 were not altered. In conclusion, we demonstrated that acute H-BCAA administration increases the pro-BDNF/total-BDNF ratio and decreases the tPA levels in animals, suggesting that the BCAA effect may depend, at least in part, on changes in BDNF post-translational processing. PMID:25681161

  20. Dietary Zinc Deficiency Affects Blood Linoleic Acid: Dihomo-γ-linolenic Acid (LA:DGLA) Ratio; a Sensitive Physiological Marker of Zinc Status in Vivo (Gallus gallus)

    PubMed Central

    Reed, Spenser; Qin, Xia; Ran-Ressler, Rinat; Brenna, James Thomas; Glahn, Raymond P.; Tako, Elad

    2014-01-01

    Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. To date, sensitive and specific biological markers of zinc status are still needed. The aim of this study was to evaluate Gallus gallus as an in vivo model in the context of assessing the sensitivity of a previously unexplored potential zinc biomarker, the erythrocyte linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio. Diets identical in composition were formulated and two groups of birds (n = 12) were randomly separated upon hatching into two diets, Zn(+) (zinc adequate control, 42.3 μg/g zinc), and Zn(−) (zinc deficient, 2.5 μg/g zinc). Dietary zinc intake, body weight, serum zinc, and the erythrocyte fatty acid profile were measured weekly. At the conclusion of the study, tissues were collected for gene expression analysis. Body weight, feed consumption, zinc intake, and serum zinc were higher in the Zn(+) control versus Zn(−) group (p < 0.05). Hepatic TNF-α, IL-1β, and IL-6 gene expression were higher in the Zn(+) control group (p < 0.05), and hepatic Δ6 desaturase was significantly higher in the Zn(+) group (p < 0.001). The LA:DGLA ratio was significantly elevated in the Zn(−) group compared to the Zn(+) group (22.6 ± 0.5 and 18.5 ± 0.5, % w/w, respectively, p < 0.001). This study suggests erythrocyte LA:DGLA is able to differentiate zinc status between zinc adequate and zinc deficient birds, and may be a sensitive biomarker to assess dietary zinc manipulation. PMID:24658588

  1. Dietary zinc deficiency affects blood linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio; a sensitive physiological marker of zinc status in vivo (Gallus gallus).

    PubMed

    Reed, Spenser; Qin, Xia; Ran-Ressler, Rinat; Brenna, James Thomas; Glahn, Raymond P; Tako, Elad

    2014-01-01

    Zinc is a vital micronutrient used for over 300 enzymatic reactions and multiple biochemical and structural processes in the body. To date, sensitive and specific biological markers of zinc status are still needed. The aim of this study was to evaluate Gallus gallus as an in vivo model in the context of assessing the sensitivity of a previously unexplored potential zinc biomarker, the erythrocyte linoleic acid: dihomo-γ-linolenic acid (LA:DGLA) ratio. Diets identical in composition were formulated and two groups of birds (n = 12) were randomly separated upon hatching into two diets, Zn⁺ (zinc adequate control, 42.3 μg/g zinc), and Zn⁻ (zinc deficient, 2.5 μg/g zinc). Dietary zinc intake, body weight, serum zinc, and the erythrocyte fatty acid profile were measured weekly. At the conclusion of the study, tissues were collected for gene expression analysis. Body weight, feed consumption, zinc intake, and serum zinc were higher in the Zn⁺ control versus Zn⁻ group (p < 0.05). Hepatic TNF-α, IL-1β, and IL-6 gene expression were higher in the Zn⁺ control group (p < 0.05), and hepatic Δ⁶ desaturase was significantly higher in the Zn⁺ group (p < 0.001). The LA:DGLA ratio was significantly elevated in the Zn⁻ group compared to the Zn⁺ group (22.6 ± 0.5 and 18.5 ± 0.5, % w/w, respectively, p < 0.001). This study suggests erythrocyte LA:DGLA is able to differentiate zinc status between zinc adequate and zinc deficient birds, and may be a sensitive biomarker to assess dietary zinc manipulation. PMID:24658588

  2. Carbon-to-nitrogen ratio affects the biomass composition and the fatty acid profile of heterotrophically grown Chlorella sp. TISTR 8990 for biodiesel production.

    PubMed

    Singhasuwan, Somruethai; Choorit, Wanna; Sirisansaneeyakul, Sarote; Kokkaew, Nakhon; Chisti, Yusuf

    2015-12-20

    Chlorella sp. TISTR 8990 was cultivated heterotrophically in media with various initial carbon-to-nitrogen ratios (C/N ratio) and at different agitation speeds. The production of the biomass, its total fatty acid content and the composition of the fatty acids were affected by the C/N ratio, but not by agitation speed in the range examined. The biomass production was maximized at a C/N mass ratio of 29:1. At this C/N ratio, the biomass productivity was 0.68gL(-1)d(-1), or nearly 1.6-fold the best attainable productivity in photoautotrophic growth. The biomass yield coefficient on glucose was 0.62gg(-1) during exponential growth. The total fatty acids (TFAs) in the freeze-dried biomass were maximum (459mgg(-1)) at a C/N ratio of 95:1. Lower values of the C/N ratio reduced the fatty acid content of the biomass. The maximum productivity of TFAs (186mgL(-1)d(-1)) occurred at C/N ratios of 63:1 and higher. At these conditions, the fatty acids were mostly of the polyunsaturated type. Allowing the alga to remain in the stationary phase for a prolonged period after N-depletion, reduced the level of monounsaturated fatty acids and the level of polyunsaturated fatty acids increased. Biotin supplementation of the culture medium reduced the biomass productivity relative to biotin-free control, but had no effect on the total fatty acid content of the biomass. PMID:26467713

  3. Impact of Omega-6 Polyunsaturated Fatty Acid:Eicosapentaenoic acid (EPA)+Docosahexaenoic Acid (DHA) Ratios in LDL Receptor Knockout (LDLr-/-) Mice on Atherosclerotic Lesion Formation and Elicited Peritoneal Macrophage Inflamm

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Objective: Very long chain omega-3 fatty acids have been associated with decreased risk of CVD. LDL receptor knockout mice were used to assess the effect of different omega-6:EPA+DHA ratios on atherosclerotic lesion formation and elicited peritoneal macrophage inflammatory response. Methods and R...

  4. Changing the omega-6 to omega-3 fatty acid ratio in sow diets alters serum, colostrum, and milk fatty acid profiles, but has minimal impact on reproductive performance.

    PubMed

    Eastwood, L; Leterme, P; Beaulieu, A D

    2014-12-01

    This experiment tested the hypothesis that reducing the omega-6 (n-6) to omega-3 (n-3) fatty acid (FA) ratio in sow diets will improve performance, characterized by increased litter size, decreased preweaning mortality, and improved growth performance. Second, we determined if the FA profile in sow and piglet blood, colostrum, and milk are altered when sows are fed diets with varied n-6:n-3 ratios and if the dietary FA ratio impacts circulating concentrations of IgG, IgA, eicosapentaenoic (EPA), or docosahexaenoic (DHA) acid. Sows (n=150) were assigned to 1 of 5 treatments (each divided into gestation and lactation diets) on d 80 of gestation. Period 1 (P1) is defined as d 80 of gestation to weaning and Period 2 (P2) refers to the subsequent breeding to weaning. Diets were wheat and barley based (5% crude fat) and treatments consisted of a control (tallow), 3 diets with plant oil-based n-6:n-3 ratios (9:1P, 5:1P, and 1:1P), and a 5:1 fish oil diet (5:1F). Litter size was unaffected by treatment during P1 and P2 (P>0.10). In P1, birth weight was unaffected by diet (P>0.10); however, weaning weight (P=0.019) and ADG from birth to weaning (P=0.011) were greatest for piglets born to 9:1P and 5:1P sows. During P2, 5:1F sows consumed 10% less feed during lactation (P=0.036), tended to have reduced piglet birth weights (P=0.052), and piglet weaning weight was reduced by 0.8 kg (P=0.040) relative to the other diets. Colostrum and piglet serum IgA and IgG concentrations were unaffected by diet (P>0.10). Serum n-3 FA were greatest in sows (P<0.01) consuming 1:1P and 5:1F diets and in their offspring (P=0.014). Serum α-linolenic acid (ALA) was greatest in 1:1P sows and EPA and DHA were greatest in 5:1F sows (P<0.01). In pre-suckle piglet serum, ALA did not differ among treatment groups (P>0.10). Relative to piglets of sows consuming the control diet, EPA was 2.5-fold greater in the 1:1P group and 4-fold greater in 5:1F group (P<0.01) before suckling. In post-suckle samples

  5. Determining the Optimum Dietary Tryptophan to Lysine Ratio in Growing Pigs Fed Diets Formulated with Hhigher Levels of Other Essential Amino Acids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies on amino acid (AA) ratios require the first limiting AA (generally Lys) to be set below the requirement estimate. Graded levels of the AA being investigated are then fed to determine the required ratio. Essential AA (EAA) not under investigation are often set at their presumed requirement ra...

  6. The Effects of Dietary Changes in the Ratio of Omega-3 to Omega-6 Polyunsaturated Fatty Acids on Lung Carcinogenesis in A/J Mice

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyunsaturated fatty acid metabolites are known to be involved in inflammation, and fatty acid precursors and metabolites may also exert genomic control over the expression of genes involved in proliferation and differentiation. Some researchers suggest that a higher ratio of omega-3/omega-6 fatty ...

  7. Ratio of Dietary n-6/n-3 Polyunsaturated Fatty Acids Independently Related to Muscle Mass Decline in Hemodialysis Patients

    PubMed Central

    Wong, Te-Chih; Chen, Yu-Tong; Wu, Pei-Yu; Chen, Tzen-Wen; Chen, Hsi-Hsien; Chen, Tso-Hsiao; Yang, Shwu-Huey

    2015-01-01

    Background n-3 polyunsaturated fatty acids (PUFAs) might be useful nutritional strategy for treating patients with sarcopenia. We evaluated the effect of the intake of dietary n-3 PUFAs on the skeletal muscle mass (SMM), appendicular skeletal muscle mass (ASM), and its determinants in patients receiving standard hemodialysis (HD) treatment for the management of end stage renal disease. Methods In this cross-sectional study, data of 111 HD patients were analyzed. Anthropometric and bioelectrical impedance measurements used to estimate the muscle mass were performed the day of dialysis immediately after the dialysis session. Routine laboratory and 3-day dietary data were also collected. The cutoff value of adequate intake (AI) for both n-3 PUFAs and alpha-linolenic acid (ALA) was 1.6 g/day and 1.1 g/day for men and women, respectively. Results The mean age, mean dietary n-3 PUFAs intake, ALA intake, ratio of n-6/n-3 PUFAs intake, SMM, and ASM of patients were 61.4 ± 10.4 years, 2.0 ± 1.3 g/day, 1.5 ± 1.0 g/day, 9.5 ± 6.7 g/day, 23.9 ± 5.5 kg, and 17.5 ± 4.5 kg, respectively. A higher SMM and ASM significantly observed in patients who achieved an AI of n-3 PUFAs. Similar trends appeared to be observed among those patients who achieved the AI of ALA, but the difference was not significantly, except for ASM (P = 0.047). No relevant differences in demographics, laboratory and nutritional parameters were observed, regardless of whether the patients achieved an AI of n-3 PUFAs. Multivariate analysis showed that the BMI and equilibrated Kt/V were independent determinants of the muscle mass. Moreover, the ratio of n-6/n-3 PUFAs was an independent risk determinant of reduced ASM in HD patients. Conclusion Patients with an AI of n-3 PUFAs had better total-body SMM and ASM. A higher dietary ratio of n-6/n-3 PUFAs seemed to be associated with a reduced muscle mass in HD patients. PMID:26466314

  8. Legume finishing provides beef with positive human dietary fatty acid ratios and consumer preference comparable with grain-finished beef.

    PubMed

    Chail, A; Legako, J F; Pitcher, L R; Griggs, T C; Ward, R E; Martini, S; MacAdam, J W

    2016-05-01

    Consumer liking, proximate composition, pH, Warner-Bratzler shear force, fatty acid composition, and volatile compounds were determined from the LM (longissimus thoracis) of cattle ( = 6 per diet) finished on conventional feedlot (USUGrain), legume, and grass forage diets. Forage diets included a condensed tannin-containing perennial legume, birdsfoot trefoil (; USUBFT), and a grass, meadow brome ( Rehmann; USUGrass). Moreover, representative retail forage (USDA Certified Organic Grass-fed [OrgGrass]) and conventional beef (USDA Choice, Grain-fed; ChGrain) were investigated ( = 6 per retail type). The ChGrain had the greatest ( < 0.05) intramuscular fat (IMF) percentage followed by USUGrain, the IMF percentage of which was greater ( < 0.05) than that of USUGrass and OrgGrass. The IMF content of USUBFT was similar ( > 0.05) to that of both USUGrain and USUGrass. Both grain-finished beef treatments were rated greater ( < 0.05) for flavor, tenderness, fattiness, juiciness, and overall liking compared with USUGrass and OrgGrass. Consumer liking of USUBFT beef tenderness, fattiness, and overall liking were comparable ( > 0.05) with that of USUGrain and ChGrain. Flavor liking was rated greatest ( < 0.05) for USUGrain and ChGrain, and that of USUBFT was intermediate ( > 0.05) to those of ChGrain, USUGrass, and OrgGrass. Cumulative SFA and MUFA concentrations were greatest ( < 0.05) in ChGrain and USUGrain, whereas USUGrass and OrgGrass had lower ( < 0.05) concentrations. Concentrations of cumulative SFA and MUFA in USUBFT were intermediate and similar ( > 0.05) to those of USUGrain and USUGrass. Each forage-finished beef treatment, USUGrass, OrgGrass, and USUBFT, had lower ( < 0.001) ratios of -6:-3 fatty acids. Hexanal was the most numerically abundant volatile compound. The concentration of hexanal increased with increasing concentrations of total PUFA. Among all the lipid degradation products (aldehydes, alcohols, furans, carboxylic acids, and ketones) measured in this

  9. Acute Copper and Ascorbic Acid Supplementation Inhibits Non-heme Iron Absorption in Humans.

    PubMed

    Olivares, Manuel; Figueroa, Constanza; Pizarro, Fernando

    2016-08-01

    The objective of the study is to determine the effect of copper (Cu) plus the reducing agent ascorbic acid (AA) on the absorption of non-heme iron (Fe). Experimental study with block design in which each subject was his own control. After signing an informed consent, 14 adult women using an effective method of contraception and negative pregnancy test received 0.5 mg Fe, as ferrous sulfate, alone or with Cu, as copper sulfate, plus ascorbic acid (AA/Cu 2/1 molar ratio) at 4/1; 6/1 and 8/1 Cu/Fe molar ratios as an aqueous solution on days 1, 2, 14, and 15 of the study. Fe absorption was assessed by erythrocyte incorporation of iron radioisotopes (55)Fe and (59)Fe. Geometric mean (range ± SD) absorption of Fe at 4/1 and 6/1 Cu/Fe molar ratios (and AA/Cu 2/1 molar ratio) and Fe alone was 57.4 % (35.7-92.1 %), 64.2 % (45.8-89.9 %), and 38.8 % (20.4-73.8 %), respectively (ANOVA for repeated measures p < 0.001; post hoc test Scheffé, p < 0.05). This is attributable to the enhancing effect of AA on non-heme Fe absorption; however, Fe absorption at Cu/Fe 8/1 molar ratio was 47.3 % (27.7-80.8) (p = NS compared with Fe alone). It was expected that Fe absorption would have been equal or greater than at 4/1 and 6/1 molar ratios. Copper in the presence of ascorbic acid inhibits non-heme Fe absorption at Cu/Fe 8/1 molar ratio. PMID:26715577

  10. Maxillary First Molar with Two Root Canals

    PubMed Central

    Rahimi, Saeed; Ghasemi, Negin

    2013-01-01

    Knowledge regarding the anatomic morphology of maxillary molars is absolutely essential for the success of endodontic treatment. The morphology of the permanent maxillary first molar has been reviewed extensively; however, the presence of two canals in a two-rooted maxillary first molar has rarely been reported in studies describing tooth and root canal anatomies. This case report presents a patient with a maxillary first molar with two roots and two root canals, who was referred to the Department of Endodontics, Tabriz University of Medical Sciences, Iran. PMID:23862051

  11. Fat source and dietary forage-to-concentrate ratio influences milk fatty-acid composition in lactating cows.

    PubMed

    Vazirigohar, M; Dehghan-Banadaky, M; Rezayazdi, K; Krizsan, S J; Nejati-Javaremi, A; Shingfield, K J

    2014-01-01

    On the basis of the potential benefits to human health there is an increased interest in producing milk containing lower-saturated fatty acid (SFA) and higher unsaturated fatty acid (FA) concentrations, including cis-9 18:1 and cis-9, trans-11-conjugated linoleic acid (CLA). Twenty-four multiparous Holstein cows were used in two experiments according to a completely randomized block design, with 21-day periods to examine the effects of incremental replacement of prilled palm fat (PALM) with sunflower oil (SFO) in high-concentrate diets containing 30 g/kg dry matter (DM) of supplemental fat (Experiment 1) or increases in the forage-to-concentrate (F : C) ratio from 39 : 61 to 48 : 52 of diets containing 30 g/kg DM of SFO (Experiment 2) on milk production, digestibility and milk FA composition. Replacing PALM with SFO had no effect on DM intake, but tended to increase organic matter digestibility, yields of milk, protein and lactose, and decreased linearly milk fat content. Substituting SFO for PALM decreased linearly milk fat 8:0 to 16:0 and cis-9 16:1, and increased linearly 18:0, cis-9 18:1, trans-18:1 (��4 to 16), 18:2 and CLA concentrations. Increases in the F : C ratio of diets containing SFO had no effect on intake, yields of milk, milk protein or milk lactose, lowered milk protein content in a quadratic manner, and increased linearly NDF digestion and milk fat secretion. Replacing concentrates with forages in diets containing SFO increased milk fat 4:0 to 10:0 concentrations in a linear or quadratic manner, decreased linearly cis-9 16:1, trans-6 to -10 18:1, 18:2n-6, trans-7, cis-9 CLA, trans-9, cis-11 CLA and trans-10, cis-12 CLA, without altering milk fat 14:0 to 16:0, trans-11 18:1, cis-9, trans-11 CLA or 18:3n-3 concentrations. In conclusion, replacing prilled palm fat on with SFO in high-concentrate diets had no adverse effects on intake or milk production, other than decreasing milk fat content, but lowered milk fat medium-chain SFA and increased

  12. CRYSTAL AND MOLECULAR STRUCTURE OF 6,6´-DIMETHOXY-GOSSYPOL:ACETIC ACID (1:1)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    By crystallization from dilute solutions of acetic acid (2-4%) in diethyl ether, acetone, or methyl ethyl ketone, 6,6´-dimethoxy-gossypol forms an inclusion complex with acetic acid in a one-to-one molar ratio. The compound crystallizes in the triclinic P1bar1¯space group and has unit cell dimensio...

  13. Compound-specific carbon, nitrogen, and hydrogen isotopic ratios for amino acids in CM and CR chondrites and their use in evaluating potential formation pathways

    NASA Astrophysics Data System (ADS)

    Elsila, Jamie E.; Charnley, Steven B.; Burton, Aaron S.; Glavin, Daniel P.; Dworkin, Jason P.

    2012-09-01

    Stable hydrogen, carbon, and nitrogen isotopic ratios (δD, δ13C, and δ15N) of organic compounds can reveal information about their origin and formation pathways. Several formation mechanisms and environments have been postulated for the amino acids detected in carbonaceous chondrites. As each proposed mechanism utilizes different precursor molecules, the isotopic signatures of the resulting amino acids may indicate the most likely of these pathways. We have applied gas chromatography with mass spectrometry and combustion isotope ratio mass spectrometry to measure the compound-specific C, N, and H stable isotopic ratios of amino acids from seven CM and CR carbonaceous chondrites: CM1/2 Allan Hills (ALH) 83100, CM2 Murchison, CM2 Lewis Cliff (LEW) 90500, CM2 Lonewolf Nunataks (LON) 94101, CR2 Graves Nunataks (GRA) 95229, CR2 Elephant Moraine (EET) 92042, and CR3 Queen Alexandra Range (QUE) 99177. We compare the isotopic compositions of amino acids in these meteorites with predictions of expected isotopic enrichments from potential formation pathways. We observe trends of decreasing δ13C and increasing δD with increasing carbon number in the α-H, α-NH2 amino acids that correspond to predictions made for formation via Strecker-cyanohydrin synthesis. We also observe light δ13C signatures for β-alanine, which may indicate either formation via Michael addition or via a pathway that forms primarily small, straight-chain, amine-terminal amino acids (n-ω-amino acids). Higher deuterium enrichments are observed in α-methyl amino acids, indicating formation of these amino acids or their precursors in cold interstellar or nebular environments. Finally, individual amino acids are more enriched in deuterium in CR chondrites than in CM chondrites, reflecting different parent-body chemistry.

  14. Compound-Specific Carbon, Nitrogen, and Hydrogen Isotopic Ratios for Amino Acids in CM and CR Chondrites and their use in Evaluating Potential Formation Pathways

    NASA Technical Reports Server (NTRS)

    Elsila, Jamie E.; Charnley, Steven B.; Burton, Aaron S.; Glavin, Daniel P.; Dworkin, Jason P.

    2012-01-01

    Stable hydrogen, carbon, and nitrogen isotopic ratios (oD, 013C, and olSN) of organic compounds can revcal information about their origin and formation pathways. Several formation mechanisms and environments have been postulated for the amino acids detected in carbonaceous chondrites. As each proposed mechanism utilizes different precursor molecules, the isotopic signatures of the resulting amino acids may indicate the most likely of these pathways. We have applied gas chromatography with mass spectrometry and combustion isotope ratio mass spectrometry to measure the compound-specific C, N, and H stable isotopic ratios of amino acids from seven CM and CR carbonaceous chondrites: CM1I2 Allan Hills (ALH) 83100, CM2 Murchison, CM2 Lewis Cliff (LEW) 90500, CM2 Lonewolf Nunataks (LON) 94101, CRZ Graves Nunataks (GRA) 95229, CRZ Elephant Moraine (EET) 92042, and CR3 Queen Alexandra Range (QUE) 99177. We compare the isotopic compositions of amino acids in these meteorites with predictions of expected isotopic enrichments from potential formation pathways. We observe trends of decreasing ODC and increasing oD with increasing carbon number in the aH, (l-NH2 amino acids that correspond to predictions made for formation via Streckercyanohydrin synthesis. We also observe light ODC signatures for -alanine, which may indicate either formation via Michael addition or via a pathway that forms primarily small, straight-chain, amine-terminal amino acids (n-ro-amino acids). Higher deuterium enrichments are observed in amethyl amino acids, indicating formation of these amino acids or their precursors in cold interstellar or nebular environments. Finally, individual amino acids are more enriched in deuterium in CR chondrites than CM chondrites, reflecting different parent-body chemistry.

  15. Influence of Ca/Mg ratio on phytoextraction properties of Salix viminalis. II. Secretion of low molecular weight organic acids to the rhizosphere.

    PubMed

    Magdziak, Z; Kozlowska, M; Kaczmarek, Z; Mleczek, M; Chadzinikolau, T; Drzewiecka, K; Golinski, P

    2011-01-01

    A hydroponic experiment in a phytotron was performed to investigate the effect of two different Ca/Mg ratios (4:1 and 1:10) and trace element ions (Cd, Cu, Pb and Zn) in solution on the efficiency of low molecular weight organic acid (LMWOA) formation in Salix viminalis rhizosphere. Depending on the Ca/Mg ratio and presence of selected trace elements at 0.5mM concentration, the amount and kind of LMWOAs in the rhizosphere were significantly affected. In physiological 4:1 Ca/Mg ratio the following complex of acids was observed: malonic (Pb, Zn), citric, lactic, maleic and succinic (Zn) acids. Under 1:10 Ca/Mg ratio, citric (Cd, Zn), maleic and succinic (Cd, Cu, Pb, Zn) acids were seen. Additionally, high accumulation of zinc and copper in all systems was observed, with the exception of those where one of the metals was at higher concentration. Summing up, the results indicate a significant role of LMWOAs in Salix phytoremediation abilities. Both effects can be modulated depending on the mutual Ca/Mg ratio. PMID:20950858

  16. Effects of acid washing on stable isotope ratios of C and N in penaeid shrimp and seagrass: Implications for food-web studies using multiple stable isotopes

    SciTech Connect

    Bunn, S.E.; Kempster, M.A.; Loneragan, N.R.

    1995-05-01

    We investigated the effects of acid washing on the carbon and nitrogen composition and stable isotope ratios of C and N in shrimp (Metapenaeus spp.) and seagrass (Enhalus acoroides). Acid washing did not affect the mean {delta}{sup 13}C ratios for juvenile Metapenaeus moyebi and resulted in only an ecologically insignificant change (0.3%) in mean {delta}{sup 13}C ratios for larger metapenaeus bennettae. In contrast, acid washing increased the mean {delta}{sup 15}N signatures of shrimp tissue ({approximately}3%) and decreased that of seagrass ({approximately}1.8%) to a degree that may confound the interpretation of food webs. The increase in %C and %N in both shrimp and seagrass after acid washing suggests that the changes in isotope ratios are due to loss of molecules comparatively low in C and N. Treating samples by acid washing also resulted in an increase in the variation among individuals for both {delta}{sup 15}N and {delta}{sup 13}C, which would lead to a loss of statistical power for testing differences between species, sites, or seasons. 13 refs., 2 figs., 1 tab.

  17. Ratios of Fatty Acids at the sn-2 Position of Triacylglycerols Containing Dihydroxy Fatty Acids in Castor Oil by Mass Sprectrometry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The triacylglycerols (TAG) containing dihydroxy fatty acids have been recently identified by mass spectrometry in castor oil. These new dihydroxy fatty acids were proposed earlier as 11,12-dihydroxy-9-octadecenoic acid (diOH18:1), 11,12-dihydroxy-9,13-octadecadienoic acid (diOH18:2) and 11,12-dihydr...

  18. Molar volumes and densities of minerals

    USGS Publications Warehouse

    Robie, Richard A.; Bethke, Philip M.

    1962-01-01

    These tables present critically chosen "best values" for the density and molar volume of selected mineral compounds. No attempt was made to be all-inclusive; rather we have tried to present data for chemically and physically well-defined phases for which the molar volume and/or density was knovvn to the order of 0. 2 percent.

  19. Potentiometric, spectroscopic, electrochemical and DFT characterization of oxovanadium(IV) complexes formed by citrate and tartrates in aqueous solution at high ligand to metal molar ratios: the effects of the trigonal bipyramidal distortion in bis-chelated species and biological implications.

    PubMed

    Lodyga-Chruscinska, Elzbieta; Sanna, Daniele; Garribba, Eugenio; Micera, Giovanni

    2008-09-28

    The complexation of VO(IV) ion with citrate (L3-), D-, L- and DL-tartrate (L2-) at high ligand to metal molar ratios was studied in aqueous solution through the combined application of potentiometric, spectroscopic (UV-vis and EPR) and electrochemical (cyclic voltammetry) techniques. Unlike in equimolar solution, mononuclear and not dinuclear species are formed with the binding of carboxylate-COO- and alcoholate-O- donors yielding mono- and bis-chelated species with VOLH, VOL, VOLH(-1) and VOL2H(-2) composition; for tartrates also the "sugar-like" (O-, O-) coordination is involved in the vanadium binding at basic pH values giving rise to the formation of VOL2H(-3) and VOL2H(-4) complexes. Among the species formed, VOL2H(-2) is characterised by a strong distortion towards the trigonal bipyramid with the two V-O(alcoholate) bonds in the equatorial and the two V-O(carboxylate) bonds in the axial positions. The geometry and electronic absorption spectra of such complexes were simulated by DFT methods and it was found that in aqueous solution the distortion follows the steric hindrance of the substituents on the alpha-carbon atom and the hydrophobicity of the ligands. The results were compared with those displayed by simple alpha-hydroxycarboxylates (glycolate, 2-hydroxyisobutyrate, 2-ethyl-2-hydroxybutyrate and benzilate). The trigonal bipyramidal distortion was correlated with the values of: i) Deltalambda = lambda2-lambda3, where lambda2 and lambda3 are the central bands in the electronic absorption spectrum; ii) |A(x)-A(y)|, where A(x) and A(y) are the 51V hyperfine coupling constants along the x and y axes in the anisotropic EPR spectrum; iii) the half-wave potential E(1/2) of oxidation of VO(IV) to the corresponding VO2(V) species in the cyclic voltammogram. Finally, a discussion on the possible form of VO(IV)-citrate complexes in blood serum is presented, where it is found that the most relevant species under physiological conditions should be [VO(citrH(-1

  20. General technique of third molar removal.

    PubMed

    Farish, Sam E; Bouloux, Gary F

    2007-02-01

    The most commonly performed surgical procedure in most oral and maxillofacial surgery practices is the removal of impacted third molars. Extensive training, skill, and experience allow this procedure to be performed in an atraumatic fashion with local anesthesia, sedation, or general anesthesia. The decision to remove symptomatic third molars is not usually difficult, but the decision to remove asymptomatic third molars is sometimes less clear and requires clinical experience. A wide body of literature (discussed elsewhere in this issue) attempts to establish clinical practice guidelines for dealing with impacted teeth. Data is beginning to accumulate from third molar studies, which hopefully will provide surgeons and their patients with evidence-based guidelines regarding elective third molar surgery. PMID:18088862

  1. Expressly fabricated molar tube bases: enhanced adhesion.

    PubMed

    Sharma, Tarun; Phull, Tarun Singh; Rana, Tarun; Kumar, Varun

    2014-06-01

    Clinicians, Orthodontists and their patients' parents often expect the best results in the shortest time span possible. Orthodontic bonding of molar tubes has been an acceptable risk in a modern era of refined biomaterials and instrumentation. Although many orthodontists still prefer banding to bonding, it is the failure rate of the tubes on molars which accounts to an impedance in molar bonding. One of the reasons for molar attachment failures is attributed to improper adaptation of the buccal tube base with or without increased thickness of composite. Merits of banding the second molars especially when these are the terminal teeth for anchorage have been overemphasized in the literature. The present article presents a simple and relatively less time consuming technique of preparing molar tubes to be bonded on tooth surfaces which may be quite difficult to isolate especially for bonding, for example, mandibular second molars. The increased surface area of the composite scaffold helps not only in enhanced bond strength but also serves to reduce the incidence of plaque accumulation given the dexterity of invitro preparation. The removal of the occlusal part of the molar tube scaffold helps in prevention of open / raised bite tendencies. The present innovation, therefore, is not merely serendipity but a structured technique to overcome a common dilemma for the clinical orthodontist. The present dictum of banding being superior to molar tube bonding may prove to be futile with trendsetting molar attachments. It is also an established fact that bonding proves to be a lesser expensive modality when compared to banding procedures. PMID:25121070

  2. Effect of Different Dietary n-6 to n-3 Fatty Acid Ratios on the Performance and Fatty Acid Composition in Muscles of Broiler Chickens

    PubMed Central

    Mandal, G. P.; Ghosh, T. K.; Patra, A. K.

    2014-01-01

    The objective of this study was to investigate the different dietary ratios of n-6 to n-3 (n-6/n-3) fatty acid (FA) on performance and n-6/n-3 FA in muscles of broiler chickens. A total of 300 one-day-old Cobb chicks were randomly assigned to 3 treatments of 10 replicates in each (10 birds/replicate). Birds were fed on a corn-soybean meal-based diet containing 1% oil during starter (day 1 to 21) and 2% oil during finisher (day 22 to 39) phases, respectively. Treatments of high, medium and low dietary n-6/n-3 FA were formulated by replacing rice bran oil with linseed oil to achieve n-6/n-3 FA close to >20:1, 10:1 and 5:1, respectively. Average daily gain, average daily feed intake, and feed conversion ratio were similar (p>0.05) among the treatments. Serum glucose, cholesterol and triglycerides concentrations were not affected (p>0.05) by dietary treatments. In breast, concentration of C18:3n-3 was significantly greater (p = 0.001) for medium and low vs high n-6/n-3 FA, while concentrations of C20:5n-3, C22:6n-3, total n-3 FA, and n-6/n-3 FA were significantly higher for low vs medium, and medium vs high dietary n-6/n-3 FA. In contrast, concentrations of C18:2 and mono-unsaturated FA (MUFA) were lower for low vs high dietary n-6/n-3 FA. In thigh muscles, concentrations of C20:5n-3 were higher (p<0.05) for medium and low vs high dietary n-6/n-3 FA, and concentrations of C18:3n-3, C22:6, and n-3 FA were greater (p<0.05) for medium vs high, low vs medium dietary n-6/n-3 FA. However, concentrations of C18:1, MUFA, n-6/n-3 were lower (p<0.05) for low and medium vs high dietary n-6/n-3 FA. In conclusion, lowering the dietary n-6/n-3 FA did not affect the performance of chickens, but enhanced beneficial long-chain n-3 FA and decreased n-6/n-3 FA in chicken breast and thigh, which could be advantageous for obtaining healthy chicken products. PMID:25358321

  3. A comparison of the use of BrimA versus soluble solids/titratable acidity ratio as a maturity standard for navel oranges

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Maturity and time of harvest for California navel oranges is primarily determined by the ratio of the soluble solids concentration (SSC) to titratable acidity (TA). This standard has been used in the industry for decades but its usefulness and relationship to flavor have often been questioned. In re...

  4. Maxillary second molar impaction in the adjacent ectopic third molar: Report of five rare cases.

    PubMed

    Souki, Bernardo Q; Cheib, Paula L; de Brito, Gabriela M; Pinto, Larissa S M C

    2015-01-01

    Maxillary second molar impaction in the adjacent ectopic third molar is a rare condition that practitioners might face in the field of pediatric dentistry and orthodontics. The early diagnosis and extraction of the adjacent ectopic third molar have been advocated, and prior research has reported a high rate of spontaneous eruption following third molar removal. However, some challenges in the daily practice are that the early diagnosis of this type of tooth impaction is difficult with conventional radiographic examination, and sometimes the early surgical removal of the maxillary third molar must be postponed because of the risks of damaging the second molar. The objective of this study is to report a case series of five young patients with maxillary second molar impaction and to discuss the difficulty of early diagnosis with the conventional radiographic examination, and unpredictability of self-correction. PMID:26321848

  5. Alterations in levels and ratios of n-3 and n-6 polyunsaturated fatty acids in the temporal cortex and liver of vervet monkeys from birth to early adulthood.

    PubMed

    Miller, Leslie R; Jorgensen, Matthew J; Kaplan, Jay R; Seeds, Michael C; Rahbar, Elaheh; Morgan, Timothy M; Welborn, Andrea; Chilton, Sarah M; Gillis, Julianne; Hester, Austin; Rukstalis, Mae; Sergeant, Susan; Chilton, Floyd H

    2016-03-15

    Deficiencies in omega-3 (n-3) long chain polyunsaturated fatty acids (LC-PUFAs) and increases in the ratio of omega-6 (n-6) to n-3 LC-PUFAs in brain tissues and blood components have been associated with psychiatric and developmental disorders. Most studies have focused on n-3 LC-PUFA accumulation in the brain from birth until 2years of age, well before the symptomatic onset of such disorders. The current study addresses changes that occur in childhood and adolescence. Postmortem brain (cortical gray matter, inferior temporal lobe; n=50) and liver (n=60) from vervet monkeys fed a uniform diet from birth through young adulthood were collected from archived tissues. Lipids were extracted and fatty acid levels determined. There was a marked reduction in the ratio of n-6 LC-PUFAs, arachidonic acid (ARA) and adrenic acid (ADR), relative to the n-3 LC-PUFA, docosahexaenoic acid (DHA), in temporal cortex lipids from birth to puberty and then a more gradual decrease though adulthood. This decrease in ratio resulted from a 3-fold accumulation of DHA levels while concentrations of ARA remained constant. Early childhood through adolescence appears to be a critical period for DHA accretion in the cortex of vervet monkeys and may represent a vulnerable stage where lack of dietary n-3 LC-PUFAs impacts development in humans. PMID:26705667

  6. Unilateral Molar Distalization: A Nonextraction Therapy

    PubMed Central

    Prasad, M. Bhanu; Sreevalli, S.

    2012-01-01

    In the recent years, nonextraction treatment approaches and noncompliance therapies have become more popular in the correction of space discrepancies. One of the conventional approaches for space gaining in the arches without patient compliance is done by using certain extra oral appliances or intraoral appliance. The greatest advantage of certain appliances like fixed functional and molar distalization appliances is that they minimize the dependence on patient cooperation. Molar distalization appliances like pendulum appliance which distalizes the molar rapidly without the need of head gear can be used in patients as a unilateral space gaining procedure due to buccal segment crowding. PMID:23320203

  7. Role of third molars in orthodontics.

    PubMed

    Almpani, Konstantinia; Kolokitha, Olga-Elpis

    2015-02-16

    The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not been discussed at the same level is their involvement in orthodontic therapy. The aim of this study is to present a review of the contemporary literature regarding the most broadly discussed aspects of the multifactorial role of third molars in orthodontics and which are of general dental interest too. PMID:25685759

  8. Effect of the ratios of unsaturated fatty acids on the expressions of genes related to fat and protein in the bovine mammary epithelial cells.

    PubMed

    Sheng, R; Yan, S M; Qi, L Z; Zhao, Y L

    2015-04-01

    The objective of this study was to evaluate the effects of the different ratios of unsaturated fatty acids (UFAs) (oleic acid, linoleic acid, and linolenic acid) on the cell viability and triacylglycerol (TAG) content, as well as the mRNA expression of the genes related to lipid and protein synthesis in bovine mammary epithelial cells (BMECs). Primary cells were isolated from the mammary glands of Holstein dairy cows and were passaged twice. Afterward, the cells were randomly allocated to six treatments, five UFA-treated groups, and one control group. For all of the treatments, the the fetal bovine serum in the culture solution was replaced with fatty acid-free BSA (1 g/L), and the cells were treated with different ratios of oleic, linoleic, and linolenic acids (0.75:4:1, 1.5:10:1, 2:13.3:1, 3:20:1, and 4:26.7:1) for 48 h, which were group 1 to group 5. The control culture solution contained only fatty acid-free BSA without UFAs (0 μM). The results indicated that the cell viability was not affected by adding different ratios of UFAs, but the accumulation of TAG was significantly influenced by supplementing with different ratios of UFAs. Adding different ratios of UFAs suppressed the expression of ACACA and FASN but had the opposite effect on the abundances of FABP3 and CD36 mRNA. The expression levels of PPARG, SPEBF1, CSN1S1, and CSN3 mRNA in the BMECs were affected significantly after adding different ratios of UFAs. Our results suggested that groups 1, 2, and 3 (0.75:4:1, 1.5:10:1, and 2:13.3:1) had stronger auxo-action on fat synthesis in the BMECs, where group 3 (2:13.3:1) was the best, followed by group 4 (3:20:1). However, group 5 (4:26.7:1) was the worst. Genes related to protein synthesis in the BMECs were better promoted in groups 2 and 3, and group 3 had the strongest auxo-action, whereas the present study only partly examined the regulation of protein synthesis at the transcriptional level; more studies on translation level are needed in the future

  9. The trans/cis ratio of unsaturated fatty acids is not applicable as biomarker for environmental stress in case of long-term contaminated habitats.

    PubMed

    Fischer, Janett; Schauer, Frieder; Heipieper, Hermann J

    2010-06-01

    Cis-trans isomerization of unsaturated fatty acids is a crucial adaptive reaction of Pseudomonas and Vibrio species to toxic organic compounds or other environmental stress factors. In order to test the long-term performance of this adaptive mechanism as well as to assess its application as biomarker for environmental contamination studies were performed in batch cultures and in continuously running sand columns, simulating long-term contamination with bisphenol A (BPA). In short-term grown batch cultures a high correlation between trans/cis ratio and added BPA concentration and toxicity was observed. In contrary, this did not occur in the case of long-term sand columns. An increase in trans/cis ratio of unsaturated fatty acids only appeared in a limited period of time. Afterwards the trans/cis ratio reached the values measured for non-stressed cultures. Cis-trans isomerization is only an urgent response mechanism that is later substituted by other adaptive mechanisms. Therefore, it can be concluded that the trans/cis ratio of unsaturated fatty acids was shown not to be an appropriate biomarker for durable stress in the environment. PMID:20352421

  10. Influence of myristic acid supplementation on energy, fatty acid and calcium metabolism of sheep as affected by dietary calcium and forage : concentrate ratio.

    PubMed

    Machmüller, A; Kreuzer, M

    2005-08-01

    In a 6 x 6 Latin square arrangement, sheep of 41 kg body weight were fed myristic acid [C14:0; 50 g/kg dry matter (DM)] supplemented to two basal diets of forage : concentrate ratios of 1 : 1.5 and 1 : 0.5 and adjusted to dietary calcium (Ca) contents of either 4.2 or 9.0 g/kg DM (the latter only together with C14:0 supplementation). Various variables of energy, fatty acid and Ca metabolism were determined in combined digestibility and respiratory chamber measurements. With C14:0 addition the energy loss via the faeces increased (p < 0.05, post hoc test) without affecting energy digestibility of the complete diet. The apparent digestibility of supplemented C14:0 was higher (p < 0.01) with approximately 0.8 in the forage-based diet than in the concentrate-based diet (approximately 0.6). The elevated levels of plasma C14:0 were mainly accompanied by reduced C18:0 and C18:1 levels. The estimated apparent content of metabolizable energy (ME) of added C14:0 was either 24.5 MJ/kg (concentrate-based diet) or 32.1 MJ/kg (forage-based diet). Extra Ca equalized these differences between basal diets and ME contents amounted to 33.0 MJ/kg on average. As expected from corresponding slight shifts in energy metabolizability, the total efficiency of ME utilization increased (p < 0.1) with C14:0. The lower level of dietary Ca was still within the range recommended, but adding C14:0 to the concentrate-based diet reduced Ca retention in the body of the sheep from 0.9 to -0.1 g/day because of an impaired (p < 0.05, post hoc test) net Ca absorption, whereas no effect was found with the forage-based diet. With C14:0 addition, plasma total phosphorus (P) and serum calcitrol levels increased (p < 0.05, post hoc test) while Ca concentrations did not clearly reflect the reduced net Ca absorption. Increasing the dietary Ca content prevented adverse effects on Ca retention in the concentrate-based diet and improved Ca retention in the forage-based diet. In conclusion, the C14

  11. Self-assembly of fatty acid-alkylboladiamine salts.

    PubMed

    Douliez, Jean-Paul; Navailles, Laurence; Nallet, Frédéric

    2006-01-17

    Long-chain fatty acids are insoluble in aqueous solution and form crystal precipitates. It is then of particular importance to determine the physicochemical parameters allowing their dispersion in water to improve their bioavailability and their utilization as surfactants. Herein, we report a study on salt-free catanionic systems in aqueous solution made of mixtures between palmitic or stearic fatty acids and alkylboladiamines (Abd's) differing by their alkyl chain length. Phase contrast microscopy, solid-state NMR, Fourier transform infrared spectroscopy, and small-angle neutron scattering were used to characterize the phase behavior of these systems at molar ratio of fatty acid to Abd of 1 and 2. Whatever the Abd and the molar ratio, fatty acids were embedded at low temperature in a bilayer gel phase which crystallizes after a period of rest. At an equimolar ratio, the gel phases transited upon raising the temperature to an isotropic phase made of worm-like micelles except in the case of the ethylenediamine chain for which a lamellar fluid phase was observed. At a molar ratio of 2 and high temperature, fatty acids were embedded in a lamellar fluid phase which self-orients with its stacking axis perpendicular to the magnetic field. However, for a long alkylboladiamine such as spermine, worm-like micelles formed. The phase behavior at high temperature is discussed in terms of molecular volume. PMID:16401110

  12. Determining D/L Ratios of Amino Acids Found in Ice Above Lake Vostok Using ESI/CIT Mass Spectroscopy

    NASA Technical Reports Server (NTRS)

    Tsapin, A.; Kanik, I.; Beegle, L. W.; Wu, L.; Cooks, R. G.

    2003-01-01

    Astrobiology is an area where longevity of (micro) organisms is of great interest. Cryospheres are common phenomena in the solar system, particularly on satellites, comets and asteroids, as well as at least some of the planets. Recent data from the Mars Global Surveyor mission suggest the possibility of permafrost or perhaps even liquid water under the Martian surface [2]. These environments may be the areas in which the probability of finding life is the highest. This issue is of concern due to the probable evolution of planetary environments such as that of Mars from more hospitable to less hospitable conditions over the history of the solar system. In addition, evaluation of the possible transfer of living organisms between planets via impact ejecta [3] is dependent on knowledge of the maximum time periods over which microorganisms can remain dormant and subsequently revive and reproduce.Amino acid racemization dating, or aminostratigraphy, has been used for many years to date biological systems, and has been examined as a possible biosignature detection technique for Mars. We have suggested using amino acid racemization as one of the most indicative biosignatures [4]. Only life systems produce preferential synthesis of L-amino acids versus D-amino acids. Almost all amino acids in terrestrial organisms can be found only in the L-enantiomeric form.We studied the level of amino acid racemization, specifically of aspartic acid, in permafrost samples from eastern Siberia. Also we analyzed samples of ice from borehole drilled to lake Vostok, Antarctica.

  13. Single-rooted primary first mandibular molar

    PubMed Central

    Haridoss, SelvaKumar; Swaminathan, Kavitha; Rajendran, Vijayakumar; Rajendran, Bharathan

    2014-01-01

    Morphological variations like single-rooted molar in primary dentition are scarce. Understanding the root canal anatomy and variations is necessary for successful root canal therapy. The purpose of the present article is to report successful endodontic treatment of primary left mandibular first molar with an abnormal morphology of a single root. This case report highlights the importance of knowledge and its applications in the management of anomalous anatomic variants which play a crucial role in the success of endodontic treatment. PMID:25150245

  14. Association of Serum n-3/n-6 Polyunsaturated Fatty Acid Ratio With T-Wave Alternans in Patients With Ischemic Heart Disease.

    PubMed

    Nodera, Minoru; Suzuki, Hitoshi; Yamada, Shinya; Kamioka, Masashi; Kaneshiro, Takashi; Kamiyama, Yoshiyuki; Takeishi, Yasuchika

    2015-01-01

    Several studies have demonstrated that oral intake of n-3 polyunsaturated fatty acids, specifically eicosapentaenoic acid (EPA), prevents ventricular tachyarrhythmias (VT) with ischemic heart disease, but the underlying mechanisms still remain unclear. Thus, we examined the relation between the serum EPA/arachidonic acid (AA) ratio and electrophysiological properties in patients with ischemic heart disease. The study subjects consisted of 57 patients (46 males, mean age, 66 ± 13 years) with ischemic heart disease. T-wave alternans (TWA) and heart rate variability were assessed by 24hour Holter ECG, and left ventricular ejection fraction (LVEF) was determined by echocardiography. Fasting blood samples were collected, and the serum EPA/AA ratio was determined. Based on a median value of the serum EPA/AA ratio, all subjects were divided into two groups: serum EPA/AA ratio below 0.33 (Group-L, n = 28) or not (Group-H, n = 29). We compared these parameters between the two groups. LVEF was not different between the two groups. The maximum value of TWA was significantly higher in Group-L than in Group-H (69.5 ± 22.8 μV versus 48.7 ± 12.0 μV, P = 0.007). In addition, VT defined as above 3 beats was observed in 7 cases (25%) in Group-L, but there were no cases of VT in Group-H (P = 0.004). However, low-frequency (LF) component, high-frequency (HF) component, LF to HF ratio, and standard deviation of all R-R intervals were not different between the two groups. These results suggest that a low EPA/AA ratio may induce cardiac electrical instability, but not autonomic nervous imbalance, associated with VT in patients with ischemic heart disease. PMID:26549288

  15. Carbohydrate/protein selection in a single meal correlated with plasma tryptophan and tyrosine ratios to neutral amino acids in fasting individuals.

    PubMed

    Møller, S E

    1986-01-01

    Plasma ratios of tryptophan (Trp) and tyrosine (Tyr) to their respective competing large neutral amino acids (LNAA) for brain uptake, serum insulin and plasma glucose concentrations were determined in 31 fasting healthy female subjects, and in two smaller groups of smokers and oral contraceptive users, who were subsequently allowed to compose individual breakfast meals from a selection of 25 dietary products. Additional blood samples were collected at 2 hr after the meal. Smokers consumed less carbohydrate (-22%) and total calories (-23%) and showed decreased basal serum insulin level, when compared to controls on the same age. Females on oral contraceptives consumed significantly more carbohydrate (+54%) and total calories (+32%) than comparable controls. In the 31 females there was no significant correlation between any of the biological variables and the intake of fat or total calories. The ratio of carbohydrate/protein eaten was significantly and directly correlated with age and with the sum of plasma ratios Trp/LNAA and Tyr/LNAA, and these independent variables associated with 37% of the variance in the ratio carbohydrate/protein consumed, as evaluated by multiple regression analysis. After the meal, the plasma ratio Tyr/LNAA was increased, whereas the ratio Trp/LNAA was decreased in subjects whose ratio carbohydrate/protein consumed was below the mean of the full sample, whereas subjects who consumed meals with a high ratio carbohydrate/protein showed an increase in plasma ratio Trp/LNAA. It is concluded that biological variables in man are significantly associated with the choice between nutrients with different carbohydrate and protein contents for breakfast. The changes in the plasma ratios Trp/LNAA and Tyr/LNAA after consumption were generally moderate. PMID:3797484

  16. New oral fat tolerance tests feature tailoring of the polyunsaturated/saturated fatty acid ratio to elicit a specific postprandial response.

    PubMed

    Dekker, Mark J; Wright, Amanda J; Mazurak, Vera C; Graham, Terry E; Marangoni, Alejandro G; Robinson, Lindsay E

    2007-12-01

    The impact of dietary fat on postprandial metabolic biomarkers for obesity-related chronic diseases, such as type-2 diabetes and cardiovascular disease, has received significant recent attention. However, there is no standard method to evaluate the postprandial response to dietary fat alone. Our goals were to develop a novel oral fat tolerance test (OFTT) consisting solely of emulsified lipids tailored for specific fatty acid compositions and to evaluate the functionality of specific ratios of polyunsaturated/saturated fatty acid (P/S) loading on postprandial triacylglyceride (TAG) concentrations. Two OFTTs of emulsified lipids were prepared with specific P/S ratios of 0.2 and 2.0. Physical characteristics of the fat blends, including TAG composition, melting point, and emulsion droplet size were quantified. Healthy, older (age>45 y) men (n=8) underwent an 8 h postprandial study wherein they received the OFTT treatment (either the P/S ratio of 0.2 or 2.0), with a total lipid load of 1 g/kg subject body mass. All subjects received both treatments separated by at least 1 week. Both the P/S 0.2 and 2.0 OFTT significantly elevated (p<0.05) blood TAG and free fatty acid concentrations for 8 h without increasing blood glucose or serum insulin concentrations. The predominant fatty acids contained in the P/S 0.2 (palmitic acid, 16:0) and 2.0 (linoleic acid, 18:2(n-6)) OFTT blends were significantly elevated in the blood (p<0.05) during their respective postprandial periods. We concluded that blood TAGs are elevated in a specific pattern through the administration of novel OFTTs with specific P/S blends without eliciting an insulin or glucose response. PMID:18059580

  17. Continuous-flow free acid monitoring method and system

    DOEpatents

    Strain, J.E.; Ross, H.H.

    1980-01-11

    A free acid monitoring method and apparatus is provided for continuously measuring the excess acid present in a process stream. The disclosed monitoring system and method is based on the relationship of the partial pressure ratio of water and acid in equilibrium with an acid solution at constant temperature. A portion of the process stream is pumped into and flows through the monitor under the influence of gravity and back to the process stream. A continuous flowing sample is vaporized at a constant temperature and the vapor is subsequently condensed. Conductivity measurements of the condensate produces a nonlinear response function from which the free acid molarity of the sample process stream is determined.

  18. Continuous-flow free acid monitoring method and system

    DOEpatents

    Strain, James E.; Ross, Harley H.

    1981-01-01

    A free acid monitoring method and apparatus is provided for continuously measuring the excess acid present in a process stream. The disclosed monitoring system and method is based on the relationship of the partial pressure ratio of water and acid in equilibrium with an acid solution at constant temperature. A portion of the process stream is pumped into and flows through the monitor under the influence of gravity and back to the process stream. A continuous flowing sample is vaporized at a constant temperature and the vapor is subsequently condensed. Conductivity measurements of the condensate produces a nonlinear response function from which the free acid molarity of the sample process stream is determined.

  19. (13)C/(12)C isotope ratios of organic acids, glucose and fructose determined by HPLC-co-IRMS for lemon juices authenticity.

    PubMed

    Guyon, Francois; Auberger, Pauline; Gaillard, Laetita; Loublanches, Caroline; Viateau, Maryse; Sabathié, Nathalie; Salagoïty, Marie-Hélène; Médina, Bernard

    2014-03-01

    High performance liquid chromatography linked to isotope ratio mass spectrometry via an interface allowing the chemical oxidation of organic matter (HPLC-co-IRMS) was used to simultaneously determine carbon 13 isotope ratio (δ(13)C) of organic acids, glucose and fructose in lime and lemon juices. Because of the significant difference between organic acids and sugars concentrations, the experimental protocol was optimised by applying a "current jump" to the IRMS device. The filament current is increased of 300μA during elution in order to enhance IRMS sensitivity. Then, analysis were performed on 35 lemon and lime fruits from various geographical origins and squeezed in the laboratory. An overall average δ(13)C values of -25.40±1.62‰, -23.83±1.82‰ and -25.67±1.72‰ is found for organic acids mixture mainly made up of citric acid, glucose and fructose, respectively. These authentic samples allowed the definition of a confidence domain to which have been confronted 30 commercial juices (24 "pure juices" and 6 coming from concentrate). Among these 30 samples, 10 present δ(13)C values outside the defined range revealing an added "C4" type organic acids or sugars, addition not specified on the label that is not in agreement with EU regulation. PMID:24176310

  20. Maxillary molar distalization with first class appliance

    PubMed Central

    Ramesh, Namitha; Palukunnu, Biswas; Ravindran, Nidhi; Nair, Preeti P

    2014-01-01

    Non-extraction treatment has gained popularity for corrections of mild-to-moderate class II malocclusion over the past few decades. The distalization of maxillary molars is of significant value for treatment of cases with minimal arch discrepancy and mild class II molar relation associated with a normal mandibular arch and acceptable profile. This paper describes our experience with a 16-year-old female patient who reported with irregularly placed upper front teeth and unpleasant smile. The patient was diagnosed to have angles class II malocclusion with moderate maxillary anterior crowding, deep bite of 4 mm on a skeletal class II base with an orthognathic maxilla and retrognathic mandible and normal growth pattern. She presented an ideal profile and so molar distalization was planned with the first-class appliance. Molars were distalised by 8 mm on the right and left quadrants and class I molar relation achieved within 4 months. The space gained was utilised effectively to align the arch and establish a class I molar and canine relation. PMID:24577171

  1. EFFECTS OF PH, SOLID/SOLUTION RATIO, IONIC STRENGTH, AND ORGANIC ACIDS ON PB AND CD ON KAOLINITE

    EPA Science Inventory

    Potentiometric and ion-selective electrode titrations together with batch sorption/desorption experiments, were performed to explain the aqueous and surface complexation reactions between kaolinite, Pb, Cd and organic acids. Variables included pH, ionic strength, metal concentrat...

  2. Low n-6/n-3 PUFA Ratio Improves Lipid Metabolism, Inflammation, Oxidative Stress and Endothelial Function in Rats Using Plant Oils as n-3 Fatty Acid Source.

    PubMed

    Yang, Li Gang; Song, Zhi Xiu; Yin, Hong; Wang, Yan Yan; Shu, Guo Fang; Lu, Hui Xia; Wang, Shao Kang; Sun, Gui Ju

    2016-01-01

    Lipid metabolism, inflammation, oxidative stress and endothelial function play important roles in the pathogenesis of cardiovascular disease (CVD), which may be affected by an imbalance in the n-6/n-3 polyunsaturated fatty acid (PUFA) ratio. This study aimed to investigate the effects of the n-6/n-3 PUFA ratio on these cardiovascular risk factors in rats fed a high-fat diet using plant oils as the main n-3 PUFA source. The 1:1 and 5:1 ratio groups had significantly decreased serum levels of total cholesterol, low-density lipoprotein cholesterol, and proinflammatory cytokines compared with the 20:1 group (p < 0.05). Additionally, the 20:1 group had significantly increased serum levels of E-Selectin, von Willebrand factor (vWF), and numerous markers of oxidative stress compared with the other groups (p < 0.05). The 1:1 group had a significantly decreased lipid peroxide level compared with the other groups (p < 0.05). Serum levels of malondialdehyde, reactive oxygen species and vWF tended to increase with n-6/n-3 PUFA ratios increasing from 5:1 to 20:1. We demonstrated that low n-6/n-3 PUFA ratio (1:1 and 5:1) had a beneficial effect on cardiovascular risk factors by enhancing favorable lipid profiles, having anti-inflammatory and anti-oxidative stress effects, and improving endothelial function. A high n-6/n-3 PUFA ratio (20:1) had adverse effects. Our results indicated that low n-6/n-3 PUFA ratios exerted beneficial cardiovascular effects, suggesting that plant oils could be used as a source of n-3 fatty acids to prevent CVD. They also suggested that we should be aware of possible adverse effects from excessive n-3 PUFA. PMID:26526061

  3. Efficiency of a pendulum appliance for molar distalization related to second and third molar eruption stage.

    PubMed

    Kinzinger, Gero S M; Fritz, Ulrike B; Sander, Franz-Günter; Diedrich, Peter R

    2004-01-01

    A modified pendulum appliance, including a distal screw and special preactivated pendulum springs (built-in straightening activation and toe-in bending), was used for bilateral maxillary molar distalization in 36 adolescent patients in various stages of the molar dentition. The patients were divided into 3 groups (PG 1-3) according to the stage of eruption of their second and third molars. In PG 1 (18 patients), eruption of the second molars had either not yet taken place or was not complete. In PG 2 (15 patients), the second molars had already developed as far as the occlusal plane, with the third molars at the budding stage. In PG 3 (3 patients), germectomy of the wisdom teeth had been carried out, and the first and second molars on both sides had completely erupted. Analysis of cephalograms to identify any changes in the sagittal plane showed that, in the direction of distalization, a tooth bud acts on the mesial neighboring tooth like a fulcrum, and that tipping of the first molars in patients in whom the second molar was still at the budding stage was thus greater. In patients whose second molars had erupted completely, the degree of tipping was greater again when a third molar bud was located in the direction of movement. After previously completed germectomy of the wisdom teeth, almost exclusively bodily distalization of both molars is possible, even without bands being applied to the second molars. However, if the first and second molars are distalized simultaneously with a pendulum appliance, the duration of therapy will be longer, greater forces will have to be applied, and more anchorage will be lost. Statistical analysis of the results of dental-angular measurements showed significant differences in the degree of molar tipping and reciprocal incisor protrusion. The degree of distal tipping of first molars was less in patients with erupted second molars (PG 2 and PG 3) than in those whose second molars were not yet erupted (PG 1). For instance, the

  4. Influence of calcium and phosphorus, lactose, and salt-to-moisture ratio on Cheddar cheese quality: changes in residual sugars and water-soluble organic acids during ripening.

    PubMed

    Upreti, P; McKay, L L; Metzger, L E

    2006-02-01

    Cheddar cheese ripening involves the conversion of lactose to glucose and galactose or galactose-6-phosphate by starter and nonstarter lactic acid bacteria. Under ideal conditions (i.e., where bacteria grow under no stress of pH, water activity, and salt), these sugars are mainly converted to lactic acid. However, during ripening of cheese, survival and growth of bacteria occurs under the stressed condition of low pH, low water activity, and high salt content. This forces bacteria to use alternate biochemical pathways resulting in production of other organic acids. The objective of this study was to determine if the level and type of organic acids produced during ripening was influenced by calcium (Ca) and phosphorus (P), residual lactose, and salt-to-moisture ratio (S/M) of cheese. Eight cheeses with 2 levels of Ca and P (0.67 and 0.47% vs. 0.53 and 0.39%, respectively), lactose at pressing (2.4 vs. 0.78%), and S/M (6.4 vs. 4.8%) were manufactured. The cheeses were analyzed for organic acids (citric, orotic, pyruvic, lactic, formic, uric, acetic, propanoic, and butyric acids) and residual sugars (lactose, galactose) during 48 wk of ripening using an HPLC-based method. Different factors influenced changes in concentration of residual sugars and organic acids during ripening and are discussed in detail. Our results indicated that the largest decrease in lactose and the largest increase in lactic acid occurred between salting and d 1 of ripening. It was interesting to observe that although the lactose content in cheese was influenced by several factors (Ca and P, residual lactose, and S/M), the concentration of lactic acid was influenced only by S/M. More lactic acid was produced in low S/M treatments compared with high S/M treatments. Although surprising for Cheddar cheese, a substantial amount (0.2 to 0.4%) of galactose was observed throughout ripening in all treatments. Minor changes in the levels of citric, uric, butyric, and propanoic acids were observed during

  5. Biogeochemical dynamics of amino acids in deep-subsurface marine sediments: Constraints from compound-specific nitrogen isotopic composition and enantiomer ratio

    NASA Astrophysics Data System (ADS)

    Yamaguchi, Y. T.; Chikaraishi, Y.; Takano, Y.; Ogawa, N. O.; Suga, H.; Yokoyama, Y.; Ohkouchi, N.

    2013-12-01

    Vast microbial populations exist in deep-subsurface marine sediments. Although amino acids in sediment pore waters are key compounds in metabolic activities of sedimentary microbes and in remineralization of carbon and nitrogen, to date little is known about their biogeochemical dynamics (e.g., sources and transformation processes) in deep-subsurface sediments. As a new approach to constrain the sources of dissolved amino acids in sediment pore waters, we analyzed compound-specific nitrogen isotopic composition (d15N) and enantiomer ratio (%D) of total hydrolysable amino acids (THAA) in sediment solid phase and dissolved hydrolysable amino acids (DHAA) in sediment pore waters from the same sediment samples. Enantiomer ratio can be an indicator of source organisms of amino acids, because specific D-amino acids (such as alanine, aspartic acid, glutamic acid, and serine) are commonly found in the cell wall complex of bacteria. Compound-specific d15N can be an indicator of microbial metabolism of amino acids, because biosynthesis and degradation of amino acids cause nitrogen isotopic fractionation. Samples were collected from deep-subsurface sediments (up to 172.9 m below seafloor) at the Sagami Trough (Northwestern Pacific) during D/V Chikyu cruise CK09-03. In the sediments deeper than 9 mbsf, %D values of DHAA were 25.9×2.8% in alanine, 24.8×2.1% in aspartic acid, 11.3×2.8% in serine, and 16.3×2.7% in glutamic acid, and %D changes from THAA were +15.3×2.1% in alanine, -0.4×2.4% in aspartic acid, -8.1×6.2% in serine, and 4.6×3.3% in glutamic acid. Compound-specific d15N analysis showed that d15N values of alanine are higher in DHAA than THAA and that d15N values of glycine and glutamic acid are similar between the two fractions (d15N of DHAA - d15N of THAA = +5.8×2.3 permill, +1.9×0.6 permill, -0.3×1.1 permill, respectively). The differences of d15N and %D signatures between DHAA and THAA suggest that the depolymerization of THAA is not the sole source of

  6. Quantification of monocarboxylic acids from a spark discharge synthesis. [in meteorites

    NASA Technical Reports Server (NTRS)

    Yuen, G. U.; Lawless, J. G.; Edelson, E. H.

    1981-01-01

    A suite of sixteen monocarboxylic acids having carbon numbers 2 to 7, formed by the Miller-Urey spark discharge process, was identified and quantified by gas chromatography and mass fragmentography using a deuterium spiking technique. The molar concentration and isomeric distribution of these laboratory synthesized monocarboxylic acids are compared to those previously reported for the Murchison meteorite. They show similar trends, namely, decreasing molar concentration with increasing molecular weight, and a ratio of normal/branched isomers tending toward smaller values with increasing carbon numbers.

  7. Influence of age and concurrent medication on steady-state valproic acid serum level-dose ratios in Japanese paediatric patients.

    PubMed

    Yukawa, E; Suzuki, A; Higuchi, S; Aoyama, T

    1991-08-01

    The effects of age and co-medication on steady-state valproic acid (VPA) level/dose (L/D) ratios were evaluated retrospectively in 382 paediatric patients. The VPA L/D ratio increased significantly with age up to 15 years of age in patients on monotherapy (L/D = 0.149 x AGE + 2.708, n = 192, r = 0.549, P less than 0.001). In patients taking three or more anti-epileptic drugs, including VPA, there was no such effect. Associated anti-epileptic therapy affected the VPA L/D ratio, which was significantly reduced in patients on polytherapy as compared to patients on monotherapy. Therefore, routine monitoring of VPA serum levels would be extremely useful, especially in the paediatric age group, and in patients who require associated anti-epileptic medication. PMID:1939408

  8. Heterologous expression of C. elegans fat-1 decreases the n-6/n-3 fatty acid ratio and inhibits adipogenesis in 3T3-L1 cells

    SciTech Connect

    An, Lei; Pang, Yun-Wei; Gao, Hong-Mei; Tao, Li; Miao, Kai; Wu, Zhong-Hong; and others

    2012-11-23

    Highlights: Black-Right-Pointing-Pointer Expression of C. elegans fat-1 reduces the n-6/n-3 PUFA ratio in 3T3-L1 cells. Black-Right-Pointing-Pointer fat-1 inhibits the proliferation and differentiation of 3T3-L1 preadipocytes. Black-Right-Pointing-Pointer fat-1 reduces lipid deposition in 3T3-L1 adipocytes. Black-Right-Pointing-Pointer The lower n-6/n-3 ratio induces apoptosis in 3T3-L1 adipocytes. -- Abstract: In general, a diet enriched in polyunsaturated fatty acids (PUFAs) inhibits the development of obesity and decreases adipose tissue. The specific impacts of n-3 and n-6 PUFAs on adipogenesis, however, have not been definitively determined. Traditional in vivo and in vitro supplementation studies have yielded inconsistent or even contradictory results, which likely reflect insufficiently controlled experimental systems. Caenorhabditiselegans fat-1 gene encodes an n-3 fatty acid desaturase, and its heterologous expression represents an effective method both for altering the n-6/n-3 PUFA ratio and for evaluating the biological effects of n-3 and n-6 PUFAs. We sought to determine whether a reduced n-6/n-3 ratio could influence adipogenesis in 3T3-L1 cells. Lentivirus-mediated introduction of the fat-1 gene into 3T3-L1 preadipocytes significantly reduced the n-6/n-3 ratio and inhibited preadipocyte proliferation and differentiation. In mature adipocytes, fat-1 expression reduced lipid deposition, as measured by Oil Red O staining, and induced apoptosis. Our results indicate that a reduced n-6/n-3 ratio inhibits adipogenesis through several mechanisms and that n-3 PUFAs more effectively inhibit adipogenesis (but not lipogenesis) than do n-6 PUFAs.

  9. A comparison of methods used to determine the oleic/linoleic acid ratio in cultivated peanut (Arachis hypogaea L.)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Peanuts are a cheap source of protein compared to cheese and red meat and a good source of essential vitamins and minerals and are thus a common component of many oil and food products. The fatty acid composition of peanuts has become increasingly important with the realization that the onset of ra...

  10. EFFECTS OF PH, SOLID/SOLUTION RATIO, IONIC STRENGTH, AND ORGANIC ACIDS ON PB AND CD SOPRTION ON KAOLINITE

    EPA Science Inventory

    Potentiometric and ion-selective electrode titrations together with batch sorption/desorption experiments, were performed to explain the aqueous and surface complexation reactions between kaolinite, Pb, Cd and three organic acids. Variables included pH, ionic strength, metal conc...

  11. Orthodontic extrusion of horizontally impacted mandibular molars

    PubMed Central

    Ma, Zhigui; Yang, Chi; Zhang, Shanyong; Xie, Qianyang; Shen, Yuqing; Shen, Pei

    2014-01-01

    Objective: To introduce and evaluate a novel approach in treating horizontally impacted mandibular second and third molars. Materials and methods: An orthodontic technique was applied for treatment of horizontally impacted mandibular second and third molars, which included a push-type spring for rotation first, and then a cantilever for extrusion. There were 8 mandibular third molars (M3s) and 2 second molars (M2s) in this study. Tooth mobility, extraction time, the inclination and parallelism of the impacted tooth, alveolar bone height of the adjacent tooth, and the relationship of impacted M3 and the inferior alveolar nerve (IAN) were evaluated. Results: Two horizontally impacted M2s could be upright in the arch and good occlusal relationships were obtained after treatment. All impacted M3s were successfully separated from the IAN, without any neurologic consequences. The average extraction time was 5 minutes. There was a significant change in the inclination and parallelism of the impacted tooth after treatment. A new bone apposition with the average height of 3.2 mm was noted distal to the adjacent tooth. Conclusions: This two-step orthodontic technique as presented here may be a safe and feasible alternative in management of severely horizontally impacted mandibular molars, which achieves a successful separation of M3s from the IAN and an excellent position for M2s. PMID:25419364

  12. Changes in PTGS1 and ALOX12 Gene Expression in Peripheral Blood Mononuclear Cells Are Associated with Changes in Arachidonic Acid, Oxylipins, and Oxylipin/Fatty Acid Ratios in Response to Omega-3 Fatty Acid Supplementation

    PubMed Central

    Berthelot, Claire C.; Kamita, Shizuo George; Sacchi, Romina; Yang, Jun; Nording, Malin L.; Georgi, Katrin; Hegedus Karbowski, Christine; German, J. Bruce; Weiss, Robert H.; Hogg, Ronald J.; Hammock, Bruce D.; Zivkovic, Angela M.

    2015-01-01

    Introduction There is a high degree of inter-individual variability among people in response to intervention with omega-3 fatty acids (FA), which may partly explain conflicting results on the effectiveness of omega-3 FA for the treatment and prevention of chronic inflammatory diseases. In this study we sought to evaluate whether part of this inter-individual variability in response is related to the regulation of key oxylipin metabolic genes in circulating peripheral blood mononuclear cells (PBMCs). Methods Plasma FA and oxylipin profiles from 12 healthy individuals were compared to PBMC gene expression profiles following six weeks of supplementation with fish oil, which delivered 1.9 g/d eicosapentaenoic acid (EPA) and 1.5 g/d docosahexaenoic acid (DHA). Fold changes in gene expression were measured by a quantitative polymerase chain reaction (qPCR). Results Healthy individuals supplemented with omega-3 FA had differential responses in prostaglandin-endoperoxide synthase 1 (PTGS1), prostaglandin-endoperoxide synthase 2 (PTGS2), arachidonate 12-lipoxygenase (ALOX12), and interleukin 8 (IL-8) gene expression in isolated PBMCs. In those individuals for whom plasma arachidonic acid (ARA) in the phosphatidylethanolamine (PE) lipid class decreased in response to omega-3 intervention, there was a corresponding decrease in gene expression for PTGS1 and ALOX12. Several oxylipin product/FA precursor ratios (e.g. prostaglandin E2 (PGE2)/ARA for PTGS1 and 12-hydroxyeicosatetraenoic acid (12-HETE)/ARA for ALOX12) were also associated with fold change in gene expression, suggesting an association between enzyme activity and gene expression. The fold-change in PTGS1 gene expression was highly positively correlated with ALOX12 gene expression but not with PTGS2, whereas IL-8 and PTGS2 were positively correlated. Conclusions The regulation of important oxylipin metabolic genes in PBMCs varied with the extent of change in ARA concentrations in the case of PTGS1 and ALOX12

  13. Oxygen from Hydrogen Peroxide. A Safe Molar Volume-Molar Mass Experiment.

    ERIC Educational Resources Information Center

    Bedenbaugh, John H.; And Others

    1988-01-01

    Describes a molar volume-molar mass experiment for use in general chemistry laboratories. Gives background technical information, procedures for the titration of aqueous hydrogen peroxide with standard potassium permanganate and catalytic decomposition of hydrogen peroxide to produce oxygen, and a discussion of the results obtained in three…

  14. Lower third molar eruption following orthodontic treatment.

    PubMed

    Salehi, P; Danaie, S Momene

    2008-01-01

    This study assessed the effect of extraction and preservation of the 1st premolar on lower 3rd molar eruption. Orthodontic clinic records from 1993 to 1995 were evaluated before and after treatment and 8-9 years after treatment for 3 groups of patients: 32 with extraction of 1st premolars in both jaws, 32 with no extraction but orthodontic treatment and 48 controls with no extraction but orthodontic treatment in the upper jaws only. Successful eruption of 3rd molars was evaluated. There was a significant difference in the rates of successful eruptions in the extraction (42%), non-extraction (12%) and control (20%) groups. The findings indicate that 1st premolar extraction may increase the chance of 3rd molar eruption, leading to a lower incidence of health and economic complications. PMID:19161121

  15. Use of calcium/aluminum ratios as indicators of stress in forest ecosystems

    SciTech Connect

    Cronan, C.S.; Grigal, D.F.

    1995-03-01

    The calcium/aluminum (Ca/Al) molar ratio of the soil solution provides a valuable measurement endpoint or ecological indicator for identification of approximate thresholds beyond which the risk of forest damage from Al stress and nutrient imbalances increases. The Ca/Al ratio can also be used as an indicator to assess forest ecosystem changes over time in response to acidic deposition, forest harvesting, or other processes contributing to acid soil infertility. Based on a critical review of literature on Al stress, we estimate that there is a 50:50 risk of adverse impacts on tree growth or nutrition when the soil solution Ca/Al ratio is as low as 1.0, a 75% risk when the soil solution ratio is as low as 0.5, and nearly a 100% risk when the soil solution Ca/Al molar ratio is as low as 0.2. The Ca/Al ratio of the soil solution can be corroborated with other complementary indices.

  16. BisGMA/TEGDMA dental nanocomposites containing glyoxylic acid modified high-aspect ratio hydroxyapatite nanofibers with enhanced dispersion

    PubMed Central

    Chen, Liang; Xu, Changqi; Wang, Yong; Shi, Jian; Yu, Qingsong

    2012-01-01

    The purpose of this research was to investigate the influence of the glyoxylic acid (GA) modification of hydroxyapatite (HAP) nanofibers on their dispersion in bisphenol A glycidyl methacrylate (BisGMA)/triethylene glycol dimethacrylate (TEGDMA) dental composites and also investigate the mechanical properties, water absorption, and water solubility of the resulting dental resins and composites. Scanning/Transmission electron microscopy (STEM) images showed that microsized HAP nanofiber bundles could be effectively broken down to individual HAP nanofibers with an average length of ~15 μm after the surface modification process. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) and thermal gravimetric analysis (TGA) characterization confirmed glyoxylic acid was chemically grafted on the HAP nanofiber surface, hypothetically by reacting with the amine group on HAP nanofiber surface. The enhanced dispersion of HAP nanofibers in dental matrix led to increased biaxial flexural strength (BFS) compared with the corresponding dental resins and composites filled with untreated HAP nanofibers. In addition, impregnation of small mass fractions of the glyoxylic acid modified HAP nanofibers into the BisGMA/TEGDMA dental resins (5wt%, 10wt%) or composites (2wt%, 3wt%) could also substantially improve the BFS in comparison with the controls(pure resins or dental composites filled with silica particles alone). Larger mass fractions could not further increase the mechanical property or even degrade the BFS values. Water behavior testing results indicated that the addition of glyoxylic acid modified HAP nanofibers resulted in higher water absorption and water solubility values which is not preferred for clinical application. In summary, well dispersed HAP nanofibers and their dental composites with enhanced mechanical property have been successfully fabricated but the water absorption and water solubility of such dental composites need to be

  17. Molar and molecular views of choice.

    PubMed

    Baum, William M

    2004-06-30

    The molar and molecular views of behavior are not different theories or levels of analysis; they are different paradigms. The molecular paradigm views behavior as composed of discrete units (responses) occurring at moments in time and strung together in chains to make up complex performances. The discrete pieces are held together as a result of association by contiguity. The molecular view has a long history both in early thought about reflexes and in associationism, and, although it was helpful to getting a science of behavior started, it has outlived its usefulness. The molar view stems from a conviction that behavior is continuous, as argued by John Dewey, Gestalt psychologists, Karl Lashley, and others. The molar paradigm views behavior as inherently extended in time and composed of activities that have integrated parts. In the molar paradigm, activities vary in their scale of organization--i.e., as to whether they are local or extended--and behavior may be controlled sometimes by short-term relations and sometimes by long-term relations. Applied to choice, the molar paradigm rests on two simple principles: (a) all behavior constitutes choice; and (b) all activities take time. Equivalence between choice and behavior occurs because every situation contains more than one alternative activity. The principle that behavior takes time refers not simply to any notion of response duration, but to the necessity that identifying one action or another requires a sample extended in time. The molecular paradigm's momentary responses are inferred from extended samples in retrospect. In this sense, momentary responses constitute abstractions, whereas extended activities constitute concrete particulars. Explanations conceived within the molecular paradigm invariably involve hypothetical constructs, because they require causes to be contiguous with responses. Explanations conceived within the molar paradigm retain direct contact with observable variables. PMID:15157981

  18. 40 CFR Table 1 to Subpart Ja of... - Molar Exhaust Volumes and Molar Heat Content of Fuel Gas Constituents

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 7 2013-07-01 2013-07-01 false Molar Exhaust Volumes and Molar Heat... Exhaust Volumes and Molar Heat Content of Fuel Gas Constituents Constituent MEVa dscf/mol MHCb Btu/mol... Inerts 0.85 0 a MEV = molar exhaust volume, dry standard cubic feet per gram-mole (dscf/g-mol)...

  19. 40 CFR Table 1 to Subpart Ja of... - Molar Exhaust Volumes and Molar Heat Content of Fuel Gas Constituents

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Molar Exhaust Volumes and Molar Heat... Exhaust Volumes and Molar Heat Content of Fuel Gas Constituents Constituent MEVa dscf/mol MHCb Btu/mol... Inerts 0.85 0 a MEV = molar exhaust volume, dry standard cubic feet per gram-mole (dscf/g-mol)...

  20. Varying ratios of omega-6: omega-3 fatty acids on the pre-and postmortem bone mineral density, bone ash, and bone breaking strength of laying chickens.

    PubMed

    Baird, H T; Eggett, D L; Fullmer, S

    2008-02-01

    The purpose of this study was to investigate the effects of varying ratios of n-6 to n-3 fatty acids in the diets of White Leghorn chickens on tibia bone characteristics [bone mineral density, bone mineral content (BMC), ash bone mineral content, bone morphology, and cortical thickness] and tibia bone strength parameters (ultimate force, bending stress, maximum strain, Young's modulus of elasticity, area under the curve, and moment of inertia). Seventy-five 16-wk-old female White Leghorn chickens were randomly assigned to 1 of 5 dietary ratios of n-6 to n-3 fatty acids: 47.8:1, 18.0:1, 7.6:1, 5.9:1, or 4.7:1. Corn oil was the n-6 fatty acid source, whereas flax oil provided the n-3 fatty acids. Bone density was measured on the left tibia via dual-energy x-ray absorptiometry (DXA) prior to killing and after excision. Bones were ashed in a muffle furnace at 500 degrees F. Tibia bones were broken by using a 3-point bending rig. Results showed no significant effect of diet on bone characteristics. There were no significant differences among diet groups for parameters of bone strength except cortical thickness (P < or = 0.01). Bone mineral content determined by ashing was significantly different by 9.2% (P < or = 0.0001) from BMC determined in vivo by DXA; however, there were no differences in ex vivo BMC and BMC ash, although they were highly correlated (r = 0.99, P < or = 0.0001). We concluded that there was no effect of n-3 fatty acids on tibia bone in mature White Leghorn chickens. The GE Lunar Prodigy DXA instrument significantly underestimated the in vivo BMC in chickens. PMID:18212376

  1. Seasonal and spatial variability of the OM/OC mass ratios and high regional correlation between oxalic acid and zinc in Chinese urban organic aerosols

    NASA Astrophysics Data System (ADS)

    Xing, L.; Fu, T.-M.; Cao, J. J.; Lee, S. C.; Wang, G. H.; Ho, K. F.; Cheng, M.-C.; You, C.-F.; Wang, T. J.

    2013-04-01

    We calculated the organic matter to organic carbon mass ratios (OM/OC mass ratios) in PM2.5 collected from 14 Chinese cities during summer and winter of 2003 and analyzed the causes for their seasonal and spatial variability. The OM/OC mass ratios were calculated two ways. Using a mass balance method, the calculated OM/OC mass ratios averaged 1.92 ± 0.39 year-round, with no significant seasonal or spatial variation. The second calculation was based on chemical species analyses of the organic compounds extracted from the PM2.5 samples using dichloromethane/methanol and water. The calculated OM/OC mass ratio in summer was relatively high (1.75 ± 0.13) and spatially-invariant due to vigorous photochemistry and secondary organic aerosol (OA) production throughout the country. The calculated OM/OC mass ratio in winter (1.59 ± 0.18) was significantly lower than that in summer, with lower values in northern cities (1.51 ± 0.07) than in southern cities (1.65 ± 0.15). This likely reflects the wider usage of coal for heating purposes in northern China in winter, in contrast to the larger contributions from biofuel and biomass burning in southern China in winter. On average, organic matter constituted 36% and 34% of Chinese urban PM2.5 mass in summer and winter, respectively. We report, for the first time, a high regional correlation between Zn and oxalic acid in Chinese urban aerosols in summer. This is consistent with the formation of stable Zn oxalate complex in the aerosol phase previously proposed by Furukawa and Takahashi (2011). We found that many other dicarboxylic acids were also highly correlated with Zn in the summer Chinese urban aerosol samples, suggesting that they may also form stable organic complexes with Zn. Such formation may have profound implications for the atmospheric abundance and hygroscopic properties of aerosol dicarboxylic acids.

  2. Retention mechanisms of citric acid in ternary kaolinite-Fe(III)-citrate acid systems using Fe K-edge EXAFS and L3,2-edge XANES spectroscopy

    DOE PAGESBeta

    Yang, Jianjun; Wang, Jian; Pan, Weinan; Regier, Tom; Hu, Yongfeng; Rumpel, Cornelia; Bolan, Nanthi; Sparks, Donald

    2016-05-23

    Organic carbon (OC) stability in tropical soils is strongly interlinked with multivalent cation interaction and mineral association. Low molecular weight organic acids (LMWOAs) represent the readily biodegradable OC. Therefore, investigating retention mechanisms of LMWOAs in mineral-cation-LMWOAs systems is critical to understanding soil C cycling. Given the general acidic conditions and dominance of kaolinite in tropical soils, we investigated the retention mechanisms of citric acid (CA) in kaolinite-Fe(III)-CA systems with various Fe/CA molar ratios at pH ~3.5 using Fe K-edge EXAFS and L-3,2-edge XANES techniques. With Fe/CA molar ratios >2, the formed ferrihydrite mainly contributed to CA retention through adsorption and/ormore » coprecipitation. With Fe/CA molar ratios from 2 to 0.5, ternary complexation of CA to kaolinite via a five-coordinated Fe(III) bridge retained higher CA than ferrihydrite-induced adsorption and/or coprecipitation. With Fe/CA molar ratios ≤ 0.5, kaolinite-Fe(III)-citrate complexation preferentially occurred, but less CA was retained than via outer-sphere kaolinite-CA complexation. This study highlighted the significant impact of varied Fe/CA molar ratios on CA retention mechanisms in kaolinite-Fe(III)-CA systems under acidic conditions, and clearly showed the important contribution of Fe-bridged ternary complexation on CA retention. In conclusion, these findings will enhance our understanding of the dynamics of CA and other LMWOAs in tropical soils.« less

  3. Phosphatidylcholine enrichment with medium chain fatty acids by immobilized phospholipase A(1) -catalyzed acidolysis.

    PubMed

    Ochoa, Angélica A; Hernández-Becerra, Josafat A; Cavazos-Garduño, Adriana; García, Hugo S; Vernon-Carter, Eduardo J

    2013-01-01

    Phospholipids are a biologically and industrially important class of compounds whose physical properties can be improved for diverse applications by substitution of medium-chain fatty acids for their native fatty acid chains. In this study, phosphatidylcholine (PC) was enriched with medium-chain fatty acids (MCFAs) by acidolysis with phospholipase A(1) (PLA(1) ) immobilized on Duolite A568. Response surface methodology was employed to evaluate the effects of the molar ratio of substrates (PC to free MCFAs), enzyme loading, and reaction temperature on the incorporation of free MCFAs into PC and on PC recovery. Enzyme loading and molar ratio of substrates contributed positively, but temperature negatively, to the incorporation of free MCFAs into PC. Increases in enzyme loading and the molar ratio of PC to free MCFAs led to increased incorporation of the latter into the former, but increased temperature had the opposite effect. By contrast, an increase in enzyme loading led to decreased PC recovery. Increased temperature had also a negative effect on PC recovery. Optimal conditions for maximum incorporation and PC recovery were molar ratio of PC to free MCFAs of 1:16, enzyme loading of 16%, and 50°C. Under these conditions, the incorporation of free MCFAs was 41% and the PC recovery was 53%. PMID:23074091

  4. Nitric acid oxide mixing ratio measurements using a rocket launched chemiluminescent instrument. Final technical report, September 1986-October 1987

    SciTech Connect

    Horvath, J.J.

    1989-01-01

    A total of 18 rocket launched parachute borne nitric oxide instruments were launched from 1977 to 1985. A very precise instrument for the measurement of the nitric oxide mixing ratio was fabricated. No changes were made in the main body of the instruments, i.e., things associated with the reaction volume. Except for the last 4 launches, however, it did not yield the required absolute values that was hoped for. Two major problems were encountered. First, the wrong choice of the background calibration gas, nitrogen, caused the first 10 data sets to be too low in the absolute mixing ratio by nearly the order of 2 to 5 ppbv. The error was realized, and air was substituted for the bias gas measurement. Second, in the desire to extend the measurement to higher altitudes, the problem of contaminating the inlet flow tube with ozone from the reagent gas was encountered. The ozone valve was opened too early in the flight and this caused the pressure in the reaction volume to exceed the pressure at the flow tube entrance, permitting the ozone to migrate backwards. This problem was restricted to an altitude above 45 km.

  5. Properties of Starch-Poly(acrylamide-co-2-acrylamido-2-methylpropanesulfonic acid) Graft Copolymers Prepared by Reactive Extrusion

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graft copolymers of starch with acrylamide and 2-acrylamido-2-methylpropanesulfonic acid (AMPS) were prepared by reactive extrusion in a twin-screw extruder. The weight ratio of total monomer to starch was fixed at 1:3, while the molar fraction of AMPS in the monomer feed ranged from 0 to 0.119. Mon...

  6. Ectopic molar pregnancy: a case report

    PubMed Central

    Bousfiha, Najoua; Erarhay, Sanaa; Louba, Adnane; Saadi, Hanan; Bouchikhi, Chahrazad; Banani, Abdelaziz; Fatemi, Hind El; Sekkal, Med; Laamarti, Afaf

    2012-01-01

    The incidence of hydatidiform moles is 1 per 1,000 pregnancies. Ectopic pregnancy occurs in 20 per 1,000 pregnancies. Thus, the incidence of the ectopic molar gestation is very rare. We report a case of tubal molar pregnancy diagnosed at the systematic histology exam of an ectopic pregnancy. We report the case of 32 years old nulliparus women who presented a vaginal bleeding, lower abdominal pain and 6 weeks amenorrhea corresponding to the last menstrual period. At the clinical examination, the arterial pressure was 100/60 mmHG. The gynecological examination was difficult because of lower abdominal pain. Serum gonadotropin activity was 3454 ui/l. Pelvic ultrasound revealed an irregular echogenic mass in the left adnexa. Diagnostic laparoscopy revealed a left-sided unruptured ampullary ectopic pregnancy. A left laparoscopic salpingectomy was performed. The systematic histologic test identified an ectopic partial molar pregnancy, which was confirmed by DNA ploidy image analysis. The patient was followed with weekly quantitative B-hCG titers until three successive B-hCG levels were negative. It is pertinent that clinicians take routine histological examination of tubal specimens in ectopic pregnancy very seriously in order to diagnose cases of ectopic molar gestations early and mount appropriate post treatment surveillance. PMID:22655097

  7. Ectopic molar pregnancy: a case report.

    PubMed

    Bousfiha, Najoua; Erarhay, Sanaa; Louba, Adnane; Saadi, Hanan; Bouchikhi, Chahrazad; Banani, Abdelaziz; El Fatemi, Hind; Sekkal, Med; Laamarti, Afaf

    2012-01-01

    The incidence of hydatidiform moles is 1 per 1,000 pregnancies. Ectopic pregnancy occurs in 20 per 1,000 pregnancies. Thus, the incidence of the ectopic molar gestation is very rare. We report a case of tubal molar pregnancy diagnosed at the systematic histology exam of an ectopic pregnancy. We report the case of 32 years old nulliparus women who presented a vaginal bleeding, lower abdominal pain and 6 weeks amenorrhea corresponding to the last menstrual period. At the clinical examination, the arterial pressure was 100/60 mmHG. The gynecological examination was difficult because of lower abdominal pain. Serum gonadotropin activity was 3454 ui/l. Pelvic ultrasound revealed an irregular echogenic mass in the left adnexa. Diagnostic laparoscopy revealed a left-sided unruptured ampullary ectopic pregnancy. A left laparoscopic salpingectomy was performed. The systematic histologic test identified an ectopic partial molar pregnancy, which was confirmed by DNA ploidy image analysis. The patient was followed with weekly quantitative B-hCG titers until three successive B-hCG levels were negative. It is pertinent that clinicians take routine histological examination of tubal specimens in ectopic pregnancy very seriously in order to diagnose cases of ectopic molar gestations early and mount appropriate post treatment surveillance. PMID:22655097

  8. Mass versus molar doses, similarities and differences.

    PubMed

    Chmielewska, A; Lamparczyk, H

    2008-11-01

    Generally, they are two systems expressing the amounts of active substance in a given drug product, i.e. mass and molar dose. Currently, the dose system based on the mass is widely used in which doses are expressed in grams or milligrams. On the other hand, the molar dose system is in direct relation to the number of molecules. Hence, the objective of this work was to compare both systems in order to find their advantages and disadvantages. Active substances belonging to the groups of antibiotics, nootropic agents, beta-blockers, vitamins, GABA-analog, COX-2 inhibitors, calcium channel antagonists, benzodiazepine receptor agonists, lipid-modifying agents (fibrates), non-steroidal anti-inflammatory drugs (profens), estrogens, neuroleptics, analgesics and benzodiazepines were considered. Moreover, products containing two active substances were also taken into account. These are mixtures of hydrochlorothiazide with active substances influencing the renin-angiotensin system and combined oral contraceptives. For each active substance, belonging to the groups mentioned above molar doses were calculated from mass doses and molar mass. Hence, groups of drugs with a single active substance, drugs with similar pharmacological activities, pharmaceutical alternatives, and drugs with a single active ingredient manufactured in different doses were compared in order to find which dose system describes more adequately differences between and within the groups mentioned above. Comparisons were supported by a number of equations, which theoretically justify the data, and relationships derived from calculations. PMID:19069248

  9. Selective alveolar corticotomy to intrude overerupted molars.

    PubMed

    Oliveira, Dauro Douglas; de Oliveira, Bruno Franco; de Araújo Brito, Helio Henrique; de Souza, Margareth Maria Gomes; Medeiros, Paulo José

    2008-06-01

    Orthodontic intrusion of overerupted molars in adults is challenging for most clinicians. Efficient intrusion can be achieved by combining selective alveolar corticotomies with a modified full-coverage maxillary splint to reduce surgical risks, treatment time, and costs for both orthodontists and patients. PMID:18538256

  10. Predictors of preinterventional patency of infarct-related artery in patients with ST-segment elevation myocardial infarction: Importance of neutrophil to lymphocyte ratio and uric acid level

    PubMed Central

    Şahin, Durmuş Yıldıray; Gür, Mustafa; Elbasan, Zafer; Yıldız, Ali; Kaya, Zekeriya; İçen, Yahya Kemal; Kıvrak, Ali; Türkoğlu, Caner; Yılmaz, Remzi; Çaylı, Murat

    2013-01-01

    BACKGROUND: Patients with ST-segment elevation myocardial infarction (STEMI) and a patent infarct-related artery (IRA) experience lower mortality and better clinical outcome, but little is known about the predictors of IRA patency before primary percutaneous coronary intervention (PCI) in the setting of STEMI. OBJECTIVE: To assess possible predictors of patency of IRA before primary PCI in patients with STEMI. METHODS: A total of 880 patients with STEMI undergoing primary PCI were prospectively included (646 male, 234 female; mean [± SD] age 58.5±12.4 years). Blood samples were obtained on admission to investigate biochemical markers. Preinterventional thrombolysis in myocardial infarction (TIMI) flow was assessed in all patients. The patients were divided into two groups according to the pre-PCI TIMI flow as impaired flow group (TIMI flow 0, 1 and 2) and normal flow group (TIMI flow 3). Transthoracic echocardiography was performed in all patients. RESULTS: Eighty-three (9.43%) patients had pre-PCI TIMI 3 flow in IRA. Uric acid levels and neutrophil to lymphocyte (N to L) ratio in the normal flow group were lower than in the impaired flow group (P<0.001 for both). However, ejection fraction (EF) was higher in the normal flow group than in the impaired flow group. Multivariate logistic regression analysis showed that IRA patency was independently associated with serum uric acid level (β 0.673 [95% CI 0.548 to 0.826]; P<0.001), N to L ratio (β 0.783 [95% CI 0.683 to 0.897]; P<0.001) and EF (β 1.033 [95% CI 1.006 to 1.061]; P=0.016). CONCLUSION: Serum uric acid level, N to L ratio and EF are independent predictors of the pre-PCI patency of IRA in patients with STEMI undergoing primary PCI. PMID:23940451

  11. Differences in the relative myocardial/organ ratios of iodine-123-BMIPP and the dimethyl-substituted iodine 123-DMIPP fatty acid analogue in humans

    SciTech Connect

    Sloof, G.W.; Comans, E.F.I.; Visser, F.C.

    1997-05-01

    Radioiodinated fatty acid analogues, modified by methyl-substitution are used for SPECT imaging of the heart. The effect of mono- and dimethyl-substitution on biodistribution was investigated in humans to evaluate their relative merits for SPECT image quality. Planar total body scans were performed in fasting patients with coronary artery disease, but without heart failure, one hour after administration of 111 MBq 15-(p-[I-123]-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP, n=7) or III MBq 15-(p-[I-123]-iodophenyl)-3,3-dimethylpentaderanoic acid (DMIPP, n=4). Because these branched fatty acids are used for cardiac imaging, we focussed on heart/organ ratios, by comparing small roi-counts in heart, liver, lung, muscle (thigh) and bladder. Statistical analysis: t-test for unpaired data. Both tracers showed good visualization of the heart. While DMIPP showed a relatively high liver uptake, increased background, ie lung, activity was found for BMIPP. In contrast to DMIPP, BMIPP also showed elevated activity in the bladder.

  12. Meta-analysis of amino acid stable nitrogen isotope ratios for estimating trophic position in marine organisms.

    PubMed

    Nielsen, Jens M; Popp, Brian N; Winder, Monika

    2015-07-01

    Estimating trophic structures is a common approach used to retrieve information regarding energy pathways, predation, and competition in complex ecosystems. The application of amino acid (AA) compound-specific nitrogen (N) isotope analysis (CSIA) is a relatively new method used to estimate trophic position (TP) and feeding relationships in diverse organisms. Here, we conducted the first meta-analysis of δ(15)N AA values from measurements of 359 marine species covering four trophic levels, and compared TP estimates from AA-CSIA to literature values derived from food items, gut or stomach content analysis. We tested whether the AA trophic enrichment factor (TEF), or the (15)N enrichment among different individual AAs is constant across trophic levels and whether inclusion of δ(15)N values from multiple AAs improves TP estimation. For the TEF of glutamic acid relative to phenylalanine (Phe) we found an average value of 6.6‰ across all taxa, which is significantly lower than the commonly applied 7.6‰. We found that organism feeding ecology influences TEF values of several trophic AAs relative to Phe, with significantly higher TEF values for herbivores compared to omnivores and carnivores, while TEF values were also significantly lower for animals excreting urea compared to ammonium. Based on the comparison of multiple model structures using the metadata of δ(15)N AA values we show that increasing the number of AAs in principle improves precision in TP estimation. This meta-analysis clarifies the advantages and limitations of using individual δ(15)N AA values as tools in trophic ecology and provides a guideline for the future application of AA-CSIA to food web studies. PMID:25843809

  13. Effect of wheat dried distillers grains and enzyme supplementation on growth rates, feed conversion ratio and beef fatty acid profile in feedlot steers.

    PubMed

    He, Z X; He, M L; Zhao, Y L; Xu, L; Walker, N D; Beauchemin, K A; McAllister, T A; Yang, W Z

    2015-10-01

    The objectives of this study were to determine: (1) the effect of wheat dried distillers grain with solubles (DDGS) inclusion, and (2) dietary feed enzyme (FE; Econase XT) supplementation in a finishing diet containing wheat DDGS on fatty acid profile of the pars costalis diaphragmatis muscle of beef cattle. A total of 160 crossbred yearling steers with initial BW of 495 ± 38 kg were blocked by BW and randomized into 16 pens (10 head/pen). The pens were randomly assigned to one of the four treatments: (1) control (CON; 10% barley silage and 90% barley grain-based concentrate, dry matter (DM) basis); (2) diet containing 30% wheat DDGS in place of barley grain without FE (WDG); (3) WDG diet supplemented with low FE (WDGL; 1 ml FE/kg DM); and (4) WDG diet supplemented with high FE (2 ml FE/kg DM). The pars costalis diaphragmatis muscle samples were collected from cattle at slaughter at the end of the finishing period (120 days) with a targeted live weight of 650 kg. No differences in organic matter intake, final BW and average daily gain were observed among treatments. However, steers fed WDG had greater (P<0.01) feed conversion ratio than those fed CON, and increasing FE application in wheat DDGS-based diets tended (P<0.10) to linearly decrease feed conversion ratio. In assessing the effects of including WDG diets without FE, concentration of total polyunsaturated fatty acids (PUFA) in muscle tended to be greater (P<0.10) for steers fed WDG than steers fed CON. In addition, inclusion of wheat DDGS into the diet increased (P<0.05) concentration of CLA and vaccenic acid (VA) in muscle and also resulted in a higher (P<0.05) ratio of n-6/n-3 PUFA compared with that from steers fed CON diet. Increasing FE application in wheat DDGS-based diets did not modify the concentrations of individual or total fatty acids. These results suggest that inclusion of wheat DDGS in finishing diets may improve fatty acid profile of beef muscle which could benefit human health. PMID

  14. Biodiesel from Canola Oil using a 1:1 Molar Mixture of Methanol and Ethanol

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Canola oil was transesterified using an equimolar mixture of ethanol and methanol with potassium hydroxide (KOH) catalyst. Effect of catalyst concentration (0.5 to 1.5% wt/wt), molar ratio of equimolar mixture of ethanol and methanol (EMEM) to canola oil (3:1 to 12:1) and reaction temperature (25 t...

  15. A COMPARISON OF LIME AND ORANGE PECTIN BY HPSGC WITH MOLAR MASS AND VISCOSITY DETECTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pectin was acid extracted from lime albedo by microwave heating under pressure. Extraction times ranged from 1 to 10 minutes. Solubilized pectin was characterized for molar mass (M), rms radius of gyration (Rg) and intrinsic viscosity (IV) by HPSEC with online light scattering and viscosity detect...

  16. Effect of Different Inclusion Level of Condensed Distillers Solubles Ratios and Oil Content on Amino Acid Digestibility of Corn Distillers Dried Grains with Solubles in Growing Pigs

    PubMed Central

    Li, P.; Xu, X.; Zhang, Q.; Liu, J. D.; Li, Q. Y.; Zhang, S.; Ma, X. K.; Piao, X. S.

    2015-01-01

    The purpose of this experiment was to determine and compare the digestibility of crude protein (CP) and amino acids (AA) in full-oil (no oil extracted) and de-oiled (oil extracted) corn distillers dried grains with solubles (DDGS) with different condensed distillers solubles (CDS) ratios. Six barrows (29.6±2.3 kg) fitted with ileal T-cannula were allotted into a 6×6 Latin square design. Each period was comprised of a 5-d adaption period followed by a 2-d collection of ileal digesta. The five test diets contained 62% DDGS as the sole source of AA. A nitrogen-free diet was used to measure the basal endogenous losses of CP and AA. Chromic oxide (0.3%) was used as an index in each diet. The results showed that CP and AA were very similar in 5 DDGS, but the standardized ileal digestibility (SID) of lysine (from 56.16% to 71.15%) and tryptophan (from 54.90% to 68.38%) had the lowest values and largest variation within the essential AA, which suggests reduced availability of AA and different levels of Maillard reactions in the five DDGS. The apparent ileal digestibility and SID of CP and most of AA in full-oil DDGS (sources 1 and 2) were greater (p<0.05) than de-oiled DDGS (sources 3, 4, and 5). Comparing the AA SID in the 5 DDGS, full-oil with low CDS ratio DDGS (source 1) had non-significantly higher values (p >0.05) than full-oil with high CDS ratio DDGS (source 2); however, the SID of most AA of de-oiled with low CDS ratios DDGS (source 3) were non-significantly lower (p>0.05) than de-oiled with high CDS ratio DDGS (source 4); and the de-oiled DDGS with middle CDS ratio (source 5) but with different drying processing had the lowest SID AA values. In conclusion, de-oiled DDGS had lower SID of CP and AA than full-oil DDGS; a higher CDS ratio tended to decrease the SID of AA in full-oil DDGS but not in de-oiled DDGS; and compared with CDS ratio, processing, especially drying, may have more of an effect on AA digestibility of DDGS. PMID:25557681

  17. Till Surgery do us Part: Unexpected Bilateral Kissing Molars

    PubMed Central

    Anish, Narayanankutty; Vivek, Velayudhannair; Thomas, Sunila; Daniel, Vineet Alex; Thomas, Jincy; Ranimol, Prasanna

    2015-01-01

    The occurrence impacted teeth, single or multiple is very common. But, phenomenon of kissing molars is an extremely rare phenomenon. Mandibular third molars are the most common impacted teeth. Mandibular first or second molars does not share the same frequency of occurrence. But, there are rare cases in which the occlusal surfaces of impacted molars are united by the same follicular space and the roots point in the opposite direction, and are termed as kissing molars. Sometimes, these teeth will be associated with pathologies. This article reports a rare case of mandibular bilateral kissing molars. PMID:25918627

  18. Effect of heat treatment on the n-3/n-6 ratio and content of polyunsaturated fatty acids in fish tissues.

    PubMed

    Schneedorferová, Ivana; Tomčala, Aleš; Valterová, Irena

    2015-06-01

    The aim of this study was to compare the effect of different heat treatments (pan-frying, oven-baking, and grilling) on the contents of polyunsaturated fatty acids (PUFAs) in fish tissue. Four fish species were examined: pike, carp, cod, and herring. High performance liquid chromatography, coupled with electrospray ionization and mass spectrometric detection (HPLC/ESI/MS), was employed for determination of intact lipid molecules containing n-3 and n-6 PUFAs. Although mostly non-polar lipids (triacylglycerols, TGs) were present in the fish tissue, the PUFAs were present preferentially in the phospholipid fraction. Omnivorous fish species (carp, herring) contained more TGs than did predatory ones (pike, cod). Higher amounts of PUFAs were detected in the marine species than in the freshwater ones. The impact of heat treatments on the lipid composition in the fish tissue seems to be species-specific, as indicated by multivariate data analysis. Herring tissue is most heat-stable, and the mildest heat treatment for PUFA preservation was oven-baking. PMID:25624225

  19. Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic plateau) in summer: a strong source from surface snow?

    NASA Astrophysics Data System (ADS)

    Legrand, M.; Preunkert, S.; Frey, M.; Bartels-Rausch, T.; Kukui, A.; King, M. D.; Savarino, J.; Kerbrat, M.; Jourdain, B.

    2014-05-01

    During the austral summer 2011/2012 atmospheric nitrous acid was investigated for the second time at the Concordia site (75°06' S, 123°33' E) located on the East Antarctic plateau by deploying a long path absorption photometer (LOPAP). Hourly mixing ratios of HONO measured in December 2011/January 2012 (35 ± 5.0 pptv) were similar to those measured in December 2010/January 2011 (30.4 ± 3.5 pptv). The large value of the HONO mixing ratio at the remote Concordia site suggests a local source of HONO in addition to weak production from oxidation of NO by the OH radical. Laboratory experiments demonstrate that surface snow removed from Concordia can produce gas phase HONO at mixing ratios half that of NOx mixing ratio produced in the same experiment at typical temperatures encountered at Concordia in summer. Using these lab data and the emission flux of NOx from snow estimated from the vertical gradient of atmospheric concentrations measured during the campaign, a mean diurnal HONO snow emission ranging between 0.5 and 0.8 × 109 molecules cm-2 s-1 is calculated. Model calculations indicate that, in addition to around 1.2 pptv of HONO produced by the NO oxidation, these HONO snow emissions can only explain 6.5 to 10.5 pptv of HONO in the atmosphere at Concordia. To explain the difference between observed and simulated HONO mixing ratios, tests were done both in the field and at lab to explore the possibility that the presence of HNO4 had biased the measurements of HONO.

  20. Large mixing ratios of atmospheric nitrous acid (HONO) at Concordia (East Antarctic Plateau) in summer: a strong source from surface snow?

    NASA Astrophysics Data System (ADS)

    Legrand, M.; Preunkert, S.; Frey, M.; Bartels-Rausch, Th.; Kukui, A.; King, M. D.; Savarino, J.; Kerbrat, M.; Jourdain, B.

    2014-09-01

    During the austral summer 2011/2012 atmospheric nitrous acid (HONO) was investigated for the second time at the Concordia site (75°06' S, 123°33' E), located on the East Antarctic Plateau, by deploying a long-path absorption photometer (LOPAP). Hourly mixing ratios of HONO measured in December 2011/January 2012 (35 ± 5.0 pptv) were similar to those measured in December 2010/January 2011 (30.4 ± 3.5 pptv). The large value of the HONO mixing ratio at the remote Concordia site suggests a local source of HONO in addition to weak production from oxidation of NO by the OH radical. Laboratory experiments demonstrate that surface snow removed from Concordia can produce gas-phase HONO at mixing ratios half that of the NOx mixing ratio produced in the same experiment at typical temperatures encountered at Concordia in summer. Using these lab data and the emission flux of NOx from snow estimated from the vertical gradient of atmospheric concentrations measured during the campaign, a mean diurnal HONO snow emission ranging between 0.5 and 0.8 × 109 molecules cm-2 s-1 is calculated. Model calculations indicate that, in addition to around 1.2 pptv of HONO produced by the NO oxidation, these HONO snow emissions can only explain 6.5 to 10.5 pptv of HONO in the atmosphere at Concordia. To explain the difference between observed and simulated HONO mixing ratios, tests were done both in the field and at lab to explore the possibility that the presence of HNO4 had biased the measurements of HONO.

  1. Transient Current Behaviour of Poly (p-hydroxybenzoic acid-co-ethylene terephthalate) Liquid Crystal Polymers

    NASA Astrophysics Data System (ADS)

    Yarramaneni, Sridharbabu; Sharma, Anu; Quamara, J. K.

    2011-07-01

    Transient current behaviour of pristine Poly (p-hydroxybenzoic acid-co-ethylene terephthalate) Liquid crystal polymer which is a copolymer of poly ethylene terephthalate and poly p-hydroxybenzoic acid referred as PET/x.PHB polymer liquid crystals have been studied at different biasing electric fields ranging from 13 kV/cm to 104.3 kV/cm and at temperatures 120° C and 250° C for molar ratio x =0.8.

  2. Testing the D / H ratio of alkenones and palmitic acid as salinity proxies in the Amazon Plume

    NASA Astrophysics Data System (ADS)

    Häggi, C.; Chiessi, C. M.; Schefuß, E.

    2015-12-01

    The stable hydrogen isotope composition of lipid biomarkers, such as alkenones, is a promising new tool for the improvement of palaeosalinity reconstructions. Laboratory studies confirmed the correlation between lipid biomarker δD composition (δDLipid), water δD composition (δDH2O) and salinity; yet there is limited insight into the applicability of this proxy in oceanic environments. To fill this gap, we test the use of the δD composition of alkenones (δDC37) and palmitic acid (δDPA) as salinity proxies using samples of surface suspended material along the distinct salinity gradient induced by the Amazon Plume. Our results indicate a positive correlation between salinity and δDH2O, while the relationship between δDH2O and δDLipid is more complex: δDPAM correlates strongly with δDH2O (r2 = 0.81) and shows a salinity-dependent isotopic fractionation factor. δDC37 only correlates with δDH2O in a small number (n = 8) of samples with alkenone concentrations > 10 ng L-1, while there is no correlation if all samples are taken into account. These findings are mirrored by alkenone-based temperature reconstructions, which are inaccurate for samples with low alkenone concentrations. Deviations in δDC37 and temperature are likely to be caused by limited haptophyte algae growth due to low salinity and light limitation imposed by the Amazon Plume. Our study confirms the applicability of δDLipid as a salinity proxy in oceanic environments. But it raises a note of caution concerning regions where low alkenone production can be expected due to low salinity and light limitation, for instance, under strong riverine discharge.

  3. Influence of nitrogen substrates and substrate C:N ratios on the nitrogen isotopic composition of amino acids from the marine bacterium Vibrio harveyi

    NASA Astrophysics Data System (ADS)

    Maki, K.; Ohkouchi, N.; Chikaraishi, Y.; Fukuda, H.; Miyajima, T.; Nagata, T.

    2014-09-01

    Nitrogen (N) isotopic compositions of individual hydrolysable amino acids (δ15NAAs) in N pools have been increasingly used for trophic position assessment and evaluation of sources and transformation processes of organic matter in marine environments. However, there are limited data about variability in δ15NAAs patterns and how this variability influences marine bacteria, an important mediator of trophic transfer and organic matter transformation. We explored whether marine bacterial δ15NAAs profiles change depending on the type and C:N ratio of the substrate. The δ15NAAs profile of a marine bacterium, Vibrio harveyi, was examined using medium containing either glutamate, alanine or ammonium as the N source [substrate C:N ratios (range, 3 to 20) were adjusted with glucose]. The data were interpreted as a reflection of isotope fractionations associated with de novo synthesis of amino acids by bacteria. Principal component analysis (PCA) using the δ15N offset values normalized to glutamate + glutamine δ15N revealed that δ15NAAs profiles differed depending on the N source and C:N ratio of the substrate. High variability in the δ15N offset of alanine and valine largely explained this bacterial δ15NAAs profile variability. PCA was also conducted using bacterial and phytoplankton (cyanobacteria and eukaryotic algae) δ15NAAs profile data reported previously. The results revealed that bacterial δ15NAAs patterns were distinct from those of phytoplankton. Therefore, the δ15NAAs profile is a useful indicator of biochemical responses of bacteria to changes in substrate conditions, serving as a potentially useful method for identifying organic matter sources in marine environments.

  4. Variation of S/G Ratio and Lignin Content in a Populus Family Influences the Release of Xylose by Dilute Acid Hydrolysis.

    SciTech Connect

    Davison, Brian H; Drescher, Sadie R; Tuskan, Gerald A; Davis, Dr. Mark F.; Nghiem, Nhuan Phu

    2006-01-01

    Wood samples from second generation Populus cross were shown to have different lignin contents and S/G ratios (S: syringyl-like lignin structures; G: guaiacyl-like lignin structures). The lignin contents varied from 22.7% to 25.8% and the S/G ratio from 1.8 to 2.3. Selected samples spanning these ranges were hydrolyzed with dilute (1%) sulfuric acid to release fermentable sugars. The conditions were chosen for partial hydrolysis of the hemicellulosic fraction to maximize the expression of variation among samples. The results indicated that both lignin contents and S/G ratio significantly affected the yield of xylose. For example, the xylose yield of the 25.8% lignin and 2.3 S/G (hihg lignin, high S/G) sample produced 30% of the theoretical yield, whereas the xylose yield of the 22.7% lignin and 1.8 S/G (low lignin, low S/G) was 55% of the theoretical value. These results indicate that lignin content and composition among genetic variants within a single species can influence the hydrolyzability of the biomass.

  5. Comparative Study of Novel Ratio Spectra and Isoabsorptive Point Based Spectrophotometric Methods: Application on a Binary Mixture of Ascorbic Acid and Rutin

    PubMed Central

    Darwish, Hany W.; Bakheit, Ahmed H.; Naguib, Ibrahim A.

    2016-01-01

    This paper presents novel methods for spectrophotometric determination of ascorbic acid (AA) in presence of rutin (RU) (coformulated drug) in their combined pharmaceutical formulation. The seven methods are ratio difference (RD), isoabsorptive_RD (Iso_RD), amplitude summation (A_Sum), isoabsorptive point, first derivative of the ratio spectra (1DD), mean centering (MCN), and ratio subtraction (RS). On the other hand, RU was determined directly by measuring the absorbance at 358 nm in addition to the two novel Iso_RD and A_Sum methods. The work introduced in this paper aims to compare these different methods, showing the advantages for each and making a comparison of analysis results. The calibration curve is linear over the concentration range of 4–50 μg/mL for AA and RU. The results show the high performance of proposed methods for the analysis of the binary mixture. The optimum assay conditions were established and the proposed methods were successfully applied for the assay of the two drugs in laboratory prepared mixtures and combined pharmaceutical tablets with excellent recoveries. No interference was observed from common pharmaceutical additives. PMID:26885440

  6. The ratio of dietary (n-6) to (n-3) fatty acids influences immune system function, eicosanoid metabolism, lipid peroxidation and vitamin E status in aged dogs.

    PubMed

    Wander, R C; Hall, J A; Gradin, J L; Du, S H; Jewell, D E

    1997-06-01

    We studied the effects of feeding experimental diets containing (n-6) to (n-3) fatty acid ratios of 31:1, 5.4:1, and 1.4:1 to 20 healthy female geriatric Beagles (9.5-11.5 y) for 8-12 wk on various indices of the immune response. Compared with the 31:1 diet, consumption of the 5.4:1 and 1.4:1 diets significantly increased (n-3) fatty acids in plasma (2.17 +/- 0.64, 9.05 +/- 0.64, 17.46 +/- 0.64 g/100 g fatty acids, respectively, P < 0.0001). Although supplementation with (n-3) fatty acids did not significantly alter the humoral immune response to keyhole limpet hemocyanin (KLH), it significantly suppressed the cell-mediated immune response based on results of a delayed-type hypersensitivity (DTH) skin test. The DTH response after intradermal injection of KLH at 24 h was significantly lower in the group consuming the 1.4:1 diet compared with the group consuming the 5.4:1 (P = 0.02) or the 31:1 diets (P = 0.04), and remained significantly suppressed at 48 h in the group fed 1.4:1 relative to the group fed 31:1. After consumption of the 1.4:1 diet, stimulated mononuclear cells produced 52% less prostaglandin E2 (PGE2) than those from dogs fed the 31:1 diet (224 +/- 74 and 451 +/- 71 pmol/L, respectively, P = 0.04). Plasma concentration of alpha-tocopherol was 20% lower in dogs fed the 1.4:1 diet compared with those fed the 31:1 diet (P = 0.04), and lipid peroxidation was greater in both plasma (P = 0.03) and urine (P = 0.002). These data suggest that although a ratio of dietary (n-6) to (n-3) fatty acids of 1.4:1 depresses the cell-mediated immune response and PGE2 production, it increases lipid peroxidation and lowers vitamin E concentration. PMID:9187636

  7. Thermal phase diagram of acetamide-benzoic acid and benzoic acid-phthalimide binary systems for solar thermal applications

    NASA Astrophysics Data System (ADS)

    Kumar, Rohitash; Kumar, Ravindra; Dixit, Ambesh

    2016-05-01

    Thermal properties of Acetamide (AM) - Benzoic acid (BA) and Benzoic acid (BA) - Phthalimide (PM) binary eutectic systems are theoretically calculated using thermodynamic principles. We found that the binary systems of AM-BA at 67.6 : 32.4 molar ratio, BA-PM at 89.7 : 10.3 molar ratio form eutectic mixtures with melting temperatures ~ 54.5 °C and 114.3 °C respectively. Calculated latent heat of fusion for these eutectic mixtures are 191 kJ/kg and 146.5 kJ/kg respectively. These melting temperatures and heat of fusions of these eutectic mixtures make them suitable for thermal energy storage applications in solar water heating and solar cooking systems.

  8. Investigation of amino acid δ 13C signatures in bone collagen to reconstruct human palaeodiets using liquid chromatography-isotope ratio mass spectrometry

    NASA Astrophysics Data System (ADS)

    Choy, Kyungcheol; Smith, Colin I.; Fuller, Benjamin T.; Richards, Michael P.

    2010-11-01

    This research presents the individual amino acid δ 13C values in bone collagen of humans ( n = 9) and animals ( n = 27) from two prehistoric shell midden sites in Korea. We obtained complete baseline separation of 16 of the 18 amino acids found in bone collagen by using liquid chromatography-isotope ratio mass spectrometry (LC-IRMS). The isotopic results reveal that the humans and animals in the two sites had similar patterns in essential amino acids (EAAs) and non-essential amino acids (NEAAs). The EAA and NEAA δ 13C values in humans are intermediate between those in marine and terrestrial animals. However, the threonine δ 13C values in humans and animals measured in this study are more highly enriched than those of other amino acids. At both sites, all amino acids in marine animals are 13C-enriched relative to those of the terrestrial animals. The isotopic evidence suggests that the Tongsamdong human had EAAs and NEAAs from marine food resources, while the Nukdo humans mainly had EAAs from terrestrial food resources but obtained NEAAs from both terrestrial and marine resources. The δ 13C isotopic differences in amino acids between marine and terrestrial animals were the largest for glycine (NEAA) and histidine (EAA) and the smallest for tyrosine (NEAA) and phenylalanine (EAA). In addition, threonine among the EAAs also had a large difference (˜8‰) in δ 13C values between marine and terrestrial animals, and has the potential to be used as an isotopic marker in palaeodietary studies. Threonine δ 13C values were used in conjunction with the established Δ 13C Glycine-phenylalanine values and produced three distinct dietary groups (terrestrial, omnivorous, and marine). In addition, threonine δ 13C values and Δ 13C Serine-phenylalanine values were discovered to separate between two dietary groups (terrestrial vs. marine), and these δ 13C values may provide a potential new indicator for investigating the distinction between marine and terrestrial protein

  9. Patients' anxieties with third molar surgery.

    PubMed

    Earl, P

    1994-10-01

    There has been little study of patients' anxieties about third molar surgery despite its widespread practice. 105 patients were invited to complete questionnaires preoperatively to assess anxieties about the procedure and to assess how well it was explained. They were also asked post operatively to assess differences from expectations, accuracy of the preoperative explanation and which aspect would worry them most should the procedure be repeated. Patients generally found their worries as expected or even better. Few found events worse with only pain (12%) and paraesthesia (13%) of note. Although 88% of patients assessed pain as better than or as expected, 43% would fear it most if the procedure was repeated. Pain is the single most feared factor despite evidence that it is usually no worse than originally feared. Reassurance and adequate pain control are the most important factors to patients in third molar surgery, and this reassurance should start at operation booking rather than on admission. PMID:7999736

  10. Minerals, phytic acid and tannin contents of 18 fruits from the Brazilian savanna.

    PubMed

    Marin, Alinne M F; Siqueira, Egle M A; Arruda, Sandra F

    2009-01-01

    The present study evaluated the nutritious potential of 18 fruits, all native of the Brazilian Cerrado biome. Mineral contents were determined by inductively coupled plasma atomic emission; phytic acid and tannin contents by a colorimetric and titrimetric method, respectively; and the potential mineral bioavailability by the molar ratio of phytic acid/mineral. Baru nut showed the highest zinc, copper, iron, phosphorus and magnesium content, and, together with macaúba, showed also the highest calcium content and caloric value. Macaúba, pitomba, ingá and murici fruits were classified as a source of iron. The jatoba and baru nut had the highest concentration of phytic acid and tannins. The [phytic acid]/[iron] and [phytic acid]/[zinc] molar ratios were higher than the critical values (14 and 10, respectively) only in the baru nuts, which suggests that iron and zinc bioavailability is low in this nut. The [phytic acid]/[calcium] molar ratios were lower than the critical value (1.56) in all analyzed fruits, which suggests that calcium is bioavailable in the fruits. PMID:19353365

  11. Removal of Deeply Impacted Mandibular Molars by Sagittal Split Osteotomy

    PubMed Central

    Isler, Sabri Cemil

    2016-01-01

    Mandibular third molars are the most common impacted teeth. Mandibular first and second molars do not share the same frequency of occurrence. In rare cases the occlusal surfaces of impacted molars are united by the same follicular space and the roots pointing in opposite direction; these are called kissing molars. In some cases, a supernumerary fourth molar can be seen as unerupted and, in this case, such a supernumerary, deeply impacted fourth molar is seen neighboring kissing molars. The extraction of deeply impacted wisdom molars from the mandible may necessitate excessive bone removal and it causes complications such as damage to the inferior alveolar nerve and iatrogenic fractures of the mandible. This case report describes the use of the sagittal split osteotomy technique to avoid extensive bone removal and protect the inferior alveolar nerve during surgical extruction of multiple impacted teeth. PMID:27429810

  12. Lipase-catalyzed interesterification of soybean oil with an omega-3 polyunsaturated fatty acid concentrate prepared from sardine oil.

    PubMed

    Akimoto, Masamichi; Izawa, Maki; Hoshino, Kazumi; Abe, Ken-Ichi; Takahashi, Hiromi

    2003-02-01

    To reduce the content of linoleoyl moiety in soybean oil, soybean oil that contains 53.0% linoleoyl moiety as molar acyl moiety composition was interesterified with an omega-3 polyunsaturated fatty acid (PUFA) concentrate (24.0 mol% eicosapentaenoic acid [EPA], 40.4 mol% docosahexaenoic acid [DHA]) prepared from sardine oil, using an immobilized sn-1,3-specific lipase from Rhizomucor miehei (Lipozyme IM). The reaction was carried out in a batch reactor at 37 degrees C under the following conditions: 500 micromol of soybean oil, molar ratio of omega-3 PUFA concentrate to soybean oil = 1.0-6.0,5.0 mL of heptane, and 30 batch interesterification units of enzyme. After the reaction time of 72 h, modified soybean oil, which contains 34.9% linoleoyl, 10.1% eicosapentaenoyl, and 14.2% docosahexaenoyl moieties, was produced at the molar reactant ratio of 6.0. In this oil, the total omega-3 acyl moiety composition reached 34.1%; the molar ratio of omega-3 to omega-6 acyl moieties was enhanced by five times compared with soybean oil. Compared with palmitic acid, DHA was kinetically six times less reactive, although the EPA was by 16% more reactive. PMID:12603099

  13. Radiographic findings on 3rd molars removed in 20-year-old men.

    PubMed

    Rajasuo, Ari; Peltola, Jaakko; Ventä, Irja; Murtomaa, Heikki

    2003-10-01

    In this study we assess radiographic findings characteristic of mandibular 3rd molars that had required either routine or surgical extraction. X-ray findings relating to acute pericoronitis were also examined. The material was collected by investigating patient records and rotational panoramic radiographs of 20-year-old Finnish male conscripts (n = 738) treated during military service because of 3rd-molar-related problems. The follicle around the crown of mandibular 3rd molars with acute pericoronitis was enlarged in 19% of cases and in 13% of chronic symptom-free pericoronitis cases (not statistically significant difference). Mandibular 3rd molars extracted surgically were more often mesially inclined than those extracted routinely (61% vs. 23%; P < 0.001), partially or totally intrabony impacted (92% vs. 66%; P < 0.001) and deep situated (on average 4.2 mm vs. 2.5 mm under the occlusal plane). Surgical extraction was also associated with the roots completely developed [92% vs. 84% of the teeth routinely extracted, odds ratio (OR) 2.6, 95% confidence interval (CI) 1.2-5.5] and with the absence of radiographic pericoronitis [around 27% vs. 39% of the teeth routinely extracted (OR 0.5, 95% CI 0.3-0.8)]. In 86% of cases the space between 2nd molar and ramus of the mandible was narrower than the 3rd molar extracted surgically, whereas this was 62% in routine extraction cases (P < 0.001). We conclude that there are some typical 3rd-molar findings in rotational panoramic radiographs that show a need for surgical extraction. PMID:14763776

  14. Comparison of K-loop Molar Distalization with that of Pendulum Appliance - A Prospective Comparative Study

    PubMed Central

    Shashidhar, Nagam Reddy; Reddy, S.Rama Koteswara

    2016-01-01

    Introduction Molar distalization is the non extraction method of managing Class II malocclusions. Aim The purpose of this study was to evaluate the skeletal and dentoalveolar effects of maxillary molar distalization with K-loop appliance, and to compare these effects with that of pendulum group. Materials and Methods Class I and dental Class II malocclusions were divided into two groups of 15 each: In Group 1 (nine females and six males; mean age, 16.0±2.6 years) patients were treated with K-Loop molar distalization supported palatally by Nance button, while in Group 2 (seven females and eight males; mean age, 15.4±4.7 years), the patients were treated with conventional pendulum appliance. Standardized lateral cephalograms were taken at the beginning of treatment (T0) and at the end of molar distalization (T1) and the changes were statistically analyzed with paired t-test. Results The results showed no statistically significant difference in the amount of molar distalization in either of the appliance groups: the mean amount of molar distal movement of 5.1±0.8 mm and 4.93±1.68 mm was observed in the Group 1 and 2 respectively. The incisors moved mesially by 1.3±0.63 mm in Group 1 and 1.57±0.58 mm in Group 2. Conclusion K-Loop molar distalizing appliance has similar skeletal and dentoalveolar effects as that of pendulum appliance, with the advantages of simple yet efficient to control the moment-force ratio to produce all types of tooth movements and also requires minimal patient co-operation. PMID:27504403

  15. A crayfish molar tooth protein with putative mineralized exoskeletal chitinous matrix properties.

    PubMed

    Tynyakov, Jenny; Bentov, Shmuel; Abehsera, Shai; Yehezkel, Galit; Roth, Ziv; Khalaila, Isam; Weil, Simy; Berman, Amir; Plaschkes, Inbar; Tom, Moshe; Aflalo, Eliahu D; Sagi, Amir

    2015-11-01

    Some crustaceans possess exoskeletons that are reinforced with calcium carbonate. In the crayfish Cherax quadricarinatus, the molar tooth, which is part of the mandibular exoskeleton, contains an unusual crystalline enamel-like apatite layer. As this layer resembles vertebrate enamel in composition and function, it offers an interesting example of convergent evolution. Unlike other parts of the crayfish exoskeleton, which is periodically shed and regenerated during the molt cycle, molar mineral deposition takes place during the pre-molt stage. The molar mineral composition transforms continuously from fluorapatite through amorphous calcium phosphate to amorphous calcium carbonate and is mounted on chitin. The process of crayfish molar formation is entirely extracellular and presumably controlled by proteins, lipids, polysaccharides, low-molecular weight molecules and calcium salts. We have identified a novel molar protein termed Cq-M15 from C. quadricarinatus and cloned its transcript from the molar-forming epithelium. Its transcript and differential expression were confirmed by a next-generation sequencing library. The predicted acidic pI of Cq-M15 suggests its possible involvement in mineral arrangement. Cq-M15 is expressed in several exoskeletal tissues at pre-molt and its silencing is lethal. Like other arthropod cuticular proteins, Cq-M15 possesses a chitin-binding Rebers-Riddiford domain, with a recombinant version of the protein found to bind chitin. Cq-M15 was also found to interact with calcium ions in a concentration-dependent manner. This latter property might make Cq-M15 useful for bone and dental regenerative efforts. We suggest that, in the molar tooth, this protein might be involved in calcium phosphate and/or carbonate precipitation. PMID:26385331

  16. Enzyme Molar Fractions: A Powerful Tool for Understanding Enzyme Kinetics.

    ERIC Educational Resources Information Center

    Serra, Juan L.; And Others

    1986-01-01

    Deduces the relationship between reduced velocity and molar fractions for productive enzyme complexes; obtains the mathematical expression of molar fractions for an enzyme with two specific binding sites per molecule; and proposes a useful plot to follow the dependence of enzyme molar fractions with the concentration of one of its ligands. (JN)

  17. Holocellulose Nanofibers of High Molar Mass and Small Diameter for High-Strength Nanopaper.

    PubMed

    Galland, Sylvain; Berthold, Fredrik; Prakobna, Kasinee; Berglund, Lars A

    2015-08-10

    Wood cellulose nanofibers (CNFs) based on bleached pulp are different from the cellulose microfibrils in the plant cell wall in terms of larger diameter, lower cellulose molar mass, and modified cellulose topochemistry. Also, CNF isolation often requires high-energy mechanical disintegration. Here, a new type of CNFs is reported based on a mild peracetic acid delignification process for spruce and aspen fibers, followed by low-energy mechanical disintegration. Resulting CNFs are characterized with respect to geometry (AFM, TEM), molar mass (SEC), and polysaccharide composition. Cellulose nanopaper films are prepared by filtration and characterized by UV-vis spectrometry for optical transparency and uniaxial tensile tests. These CNFs are unique in terms of high molar mass and cellulose-hemicellulose core-shell structure. Furthermore, the corresponding nanopaper structures exhibit exceptionally high optical transparency and the highest mechanical properties reported for comparable CNF nanopaper structures. PMID:26151837

  18. Molar extinction coefficients of solutions of some organic compounds

    NASA Astrophysics Data System (ADS)

    Singh, Kulwant; Sandhu, G. K.; Lark, B. S.

    2004-05-01

    Molar extinction coefficients of aqueous solutions of some organic compounds, viz. formamide (CH_{3}NO), N-methylformamide (C_{2}H_{5}NO), NN-dimethylformamide (C_{3}H_{7}NO), NN-dimethylacetamide (C_{4}H_{9}NO), 1,4-dioxane (C_{4}H_{8}O_{2}), succinimide (C_{4}H_{5}NO_{2}) and solutions of acetamide (C_{2}H_{5}NO) and benzoic acid (C_{7}H_{6}O_{2}) in 1,4-dioxane (C_{4}H_{8}O_{2}) have been determined by narrow beam gamma-ray transmission method at 81, 356, 511, 662, 1173 and 1332 keV. The experimental values of mass attenuation coefficients of these compounds have been used to calculate effective atomic numbers and electron densities. The additivity rule earlier used for aqueous solution has been extended to non-aqueous (1,4-dioxane) solutions.

  19. Molar tubal ectopic pregnancy: Report of two cases.

    PubMed

    Mbarki, Chaouki; Jerbi, Emna; Hsayaoui, Najeh; Zouari, Fatma; Ben Brahim, Ehsen; Oueslati, Hedhili

    2015-06-01

    Ectopic molar pregnancy is a rare occurrence and consequently not often considered as a diagnostic possibility. We report two cases of molar hydatidiform tubal pregnancy. Diagnosis of ectopic pregnancy was confirmed on clinical biological and sonographic investigations. Diagnosis of molar pregnancy was done on histopathology. The clinical course was favorable for both patients. Although rare, molar changes can occur at any site of an ectopic pregnancy. Clinical diagnosis of a molar pregnancy is difficult but histopathology is the gold standard for diagnosis. PMID:25510265

  20. Hydrothermal synthesis, experimental and theoretical characterization of a novel cocrystal compound in the 2:1 stoichiometric ratio containing 6-methyluracil and dipicolinic acid

    NASA Astrophysics Data System (ADS)

    Eshtiagh-Hosseini, H.; Aghabozorg, H.; Mirzaei, M.; Beyramabadi, S. A.; Eshghi, H.; Morsali, A.; Shokrollahi, A.; Aghaei, R.

    2011-05-01

    This paper reports the hydrothermal synthesis, experimental and theoretical studies of a novel cocrystal compound in the 2:1 stoichiometric ratio of 6-methyluracil (6mu) and dipicolinic acid (pydcH 2) formulated as [6mu] 2[pydcH 2] (1), for the first time. DFT calculations were performed to access the most possible geometry of the title cocrystal compound. All calculations were carried out with the B3LYP hybrid density functional level and 6-311+G(d,p) basis sets. The vibrational frequencies together with the 1H and 13C NMR chemical shifts have been calculated on the fully optimized geometry of 1. The theoretical results are in good agreement with the experimental and solution data. The theoretical, solution, and experimental (elemental analysis, mass spectrometry, FTIR, 1H and 13C NMR spectroscopies) results confirmed our proposed structure for 1 in the 2:1 stoichiometric ratio of 6mu and pydcH 2, respectively. The protonation and equilibrium constants of 6mu and pydcH 2 and constituent systems were determined by potentiometric studies and the corresponding distribution diagrams depicted.

  1. Organic Reference Materials for Hydrogen, Carbon, and Nitrogen Stable Isotope-Ratio Measurements: Caffeines, n-Alkanes, Fatty Acid Methyl Esters, Glycines, L-Valines, Polyethylenes, and Oils.

    PubMed

    Schimmelmann, Arndt; Qi, Haiping; Coplen, Tyler B; Brand, Willi A; Fong, Jon; Meier-Augenstein, Wolfram; Kemp, Helen F; Toman, Blaza; Ackermann, Annika; Assonov, Sergey; Aerts-Bijma, Anita T; Brejcha, Ramona; Chikaraishi, Yoshito; Darwish, Tamim; Elsner, Martin; Gehre, Matthias; Geilmann, Heike; Gröning, Manfred; Hélie, Jean-François; Herrero-Martín, Sara; Meijer, Harro A J; Sauer, Peter E; Sessions, Alex L; Werner, Roland A

    2016-04-19

    An international project developed, quality-tested, and determined isotope-δ values of 19 new organic reference materials (RMs) for hydrogen, carbon, and nitrogen stable isotope-ratio measurements, in addition to analyzing pre-existing RMs NBS 22 (oil), IAEA-CH-7 (polyethylene foil), and IAEA-600 (caffeine). These new RMs enable users to normalize measurements of samples to isotope-δ scales. The RMs span a range of δ(2)H(VSMOW-SLAP) values from -210.8 to +397.0 mUr or ‰, for δ(13)C(VPDB-LSVEC) from -40.81 to +0.49 mUr and for δ(15)N(Air) from -5.21 to +61.53 mUr. Many of the new RMs are amenable to gas and liquid chromatography. The RMs include triads of isotopically contrasting caffeines, C16 n-alkanes, n-C20-fatty acid methyl esters (FAMEs), glycines, and l-valines, together with polyethylene powder and string, one n-C17-FAME, a vacuum oil (NBS 22a) to replace NBS 22 oil, and a (2)H-enriched vacuum oil. A total of 11 laboratories from 7 countries used multiple analytical approaches and instrumentation for 2-point isotopic normalization against international primary measurement standards. The use of reference waters in silver tubes allowed direct normalization of δ(2)H values of organic materials against isotopic reference waters following the principle of identical treatment. Bayesian statistical analysis yielded the mean values reported here. New RMs are numbered from USGS61 through USGS78, in addition to NBS 22a. Because of exchangeable hydrogen, amino acid RMs currently are recommended only for carbon- and nitrogen-isotope measurements. Some amino acids contain (13)C and carbon-bound organic (2)H-enrichments at different molecular sites to provide RMs for potential site-specific isotopic analysis in future studies. PMID:26974360

  2. Periodontal changes following molar intrusion with miniscrews

    PubMed Central

    Bayani, Shahin; Heravi, Farzin; Radvar, Mehrdad; Anbiaee, Najmeh; Madani, Azam Sadat

    2015-01-01

    Background: With the introduction of skeletal anchorage system, recently it is possible to successfully intrude molar teeth. On the other hand, there have been concerns about periodontal changes associated with intrusion and there are few studies on this topic, especially for posterior teeth. Materials and Methods: Ten female patients were enrolled in this study. Maxillary molar intrusion was achieved by inserting two miniscrews and a 17 × 25 titanium molybdenum alloy spring. Crestal height changes were evaluated at three intervals including: Baseline (T0), end of active treatment (T1) and 6 months after retention (T2). Other variables including probing depth, gingival recession, attachment level and bleeding on probing were evaluated by clinical measurements in the three above mentioned intervals. One-sample Kolmogrov-Smirnov test ascertained the normality of the data. For all patients, the changes in tooth position and crestal height were evaluated using one-sample t-test. (P < 0.05) Results: Supra-erupted molars were successfully intruded a mean of 2.1 ± 0.9 mm during active treatment (T0-T1). A mean bone resorption of 0.9 ± 0.9 mm in mesial crest and 1 ± 0.8 mm in distal crest had occurred in total treatment (T0-T2). A mean of 0.6 ± 1.4 mm bone was deposited on mesial crest during the retention period (T1-T2) following tooth relapse. On average, 0.8 ± 0.4 mm attachment gain was obtained. Gingival margin coronalized a mean of 0.8 ± 0.6 mm throughout the entire treatment. Probing depth showed no significant change during treatment. Conclusion: Within the limitations of this study, these results suggest that not only periodontal status was not negatively affected by intrusion, but also there were signs of periodontal improvement including attachment gain and shortening of clinical crown height. PMID:26288629

  3. Angle Class II, subdivision, with agenesis of mandibular second molars and extrusion of maxillary second molars *

    PubMed Central

    Tavares, Rubens Rodrigues

    2015-01-01

    This clinical case reports the treatment of an Angle Class II malocclusion in a young woman with a balanced face affected by agenesis of second and third mandibular molars and subsequent extrusion of second maxillary molars. The atypical and peculiar occlusal anomaly led to individualized treatment proposed in order to normalize dental malpositions, with subsequent rehabilitation of edentulous areas by means of a multidisciplinary approach. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) in partial fulfillment of the requirements for obtaining the title of certified by the BBO. PMID:25992995

  4. Preparation and application of molecularly imprinted polymer for isolation of chicoric acid from Chicorium intybus L. medicinal plant.

    PubMed

    Saad, Engy M; Madbouly, Adel; Ayoub, Nahla; El Nashar, Rasha Mohamed

    2015-06-01

    Molecularly imprinted polymer (MIP) was synthesized and applied for the extraction of chicoric acid from Chicory herb (Chicorium intybus L.). A computational study was developed to find a suitable template to functional monomer molar ratio for MIP preparations. The molar ratio was chosen based on the comparison of the binding energy of the complexes between the template and functional monomers. Based on the computational results, eight different polymers were prepared using chicoric acid as the template. The MIPs were synthesized in a non-covalent approach via thermal free-radical polymerization, using two different polymerization methods, bulk and suspension. Batch rebinding experiments were performed to evaluate the binding properties of the imprinted polymers. The best results were obtained with a MIP prepared using bulk polymerization with 4-vinylpyridine (4-VP) as the functional monomer and ethylene glycol dimethacrylate (EGDMA) as the crosslinker with a molar ratio of 1:4:20. The best MIP showed selective binding ability toward chicoric acid in the presence of the template's structural analogues, caffeic acid, caftaric acid and chlorogenic acid. PMID:26002213

  5. Mechanics analysis of molar tooth splitting.

    PubMed

    Barani, Amir; Chai, Herzl; Lawn, Brian R; Bush, Mark B

    2015-03-01

    A model for the splitting of teeth from wedge loading of molar cusps from a round indenting object is presented. The model is developed in two parts: first, a simple 2D fracture mechanics configuration with the wedged tooth simulated by a compact tension specimen; second, a full 3D numerical analysis using extended finite element modeling (XFEM) with an embedded crack. The result is an explicit equation for splitting load in terms of indenter radius and key tooth dimensions. Fracture experiments on extracted human molars loaded axially with metal spheres are used to quantify the splitting forces and thence to validate the model. The XFEM calculations enable the complex crack propagation, initially in the enamel coat and subsequently in the interior dentin, to be followed incrementally with increasing load. The fracture evolution is shown to be stable prior to failure, so that dentin toughness, not strength, is the controlling material parameter. Critical conditions under which tooth splitting in biological and dental settings are likely to be met, however rare, are considered. PMID:25584989

  6. Clinical significance of computed tomography assessment for third molar surgery.

    PubMed

    Nakamori, Kenji; Tomihara, Kei; Noguchi, Makoto

    2014-07-28

    Surgical extraction of the third molar is the most commonly performed surgical procedure in the clinical practice of oral surgery. Third molar surgery is warranted when there is inadequate space for eruption, malpositioning, or risk for cyst or odontogenic tumor formation. Preoperative assessment should include a detailed morphologic analysis of the third molar and its relationship to adjacent structures and surrounding tissues. Due to developments in medical engineering technology, computed tomography (CT) now plays a critical role in providing the clear images required for adequate assessment prior to third molar surgery. Removal of the maxillary third molar is associated with a risk for maxillary sinus perforation, whereas removal of the mandibular third molar can put patients at risk for a neurosensory deficit from damage to the lingual nerve or inferior alveolar nerve. Multiple factors, including demographic, anatomic, and treatment-related factors, influence the incidence of nerve injury during or following removal of the third molar. CT assessment of the third molar prior to surgery can identify some of these risk factors, such as the absence of cortication between the mandibular third molar and the inferior alveolar canal, prior to surgery to reduce the risk for nerve damage. This topic highlight presents an overview of the clinical significance of CT assessment in third molar surgery. PMID:25071882

  7. Clinical significance of computed tomography assessment for third molar surgery

    PubMed Central

    Nakamori, Kenji; Tomihara, Kei; Noguchi, Makoto

    2014-01-01

    Surgical extraction of the third molar is the most commonly performed surgical procedure in the clinical practice of oral surgery. Third molar surgery is warranted when there is inadequate space for eruption, malpositioning, or risk for cyst or odontogenic tumor formation. Preoperative assessment should include a detailed morphologic analysis of the third molar and its relationship to adjacent structures and surrounding tissues. Due to developments in medical engineering technology, computed tomography (CT) now plays a critical role in providing the clear images required for adequate assessment prior to third molar surgery. Removal of the maxillary third molar is associated with a risk for maxillary sinus perforation, whereas removal of the mandibular third molar can put patients at risk for a neurosensory deficit from damage to the lingual nerve or inferior alveolar nerve. Multiple factors, including demographic, anatomic, and treatment-related factors, influence the incidence of nerve injury during or following removal of the third molar. CT assessment of the third molar prior to surgery can identify some of these risk factors, such as the absence of cortication between the mandibular third molar and the inferior alveolar canal, prior to surgery to reduce the risk for nerve damage. This topic highlight presents an overview of the clinical significance of CT assessment in third molar surgery. PMID:25071882

  8. Positional changes of the third molar in orthodontically treated patients

    PubMed Central

    Mihai, AM; Lulache, IR; Grigore, R; Sanabil, AS; Boiangiu, S; Ionescu, E

    2013-01-01

    Objective and Rationale. Over the years, the effects of the third molars eruption on the dental arches have been studied extensively. Still, literature provides less data regarding the effects of the orthodontic treatment on the third molars position. The aim of our study was to assess the positional changes of the third molars relative to the occlusal plane and to the second molar long axis, changes occurred during orthodontic treatment performed with or without premolar extractions. Method. This study included 20 orthodontic treated patients: 10 of them with premolar extractions and 10 without premolar extractions. The pretreatment and post treatment panoramic radiographs were analyzed, and the angles between the third molar long axis and the occlusal plane and between the long axis of the third molar and the long axis of the second molar were measured. Results. Changes in third molar position, from pretreatment to post treatment, for the two groups of patients were evaluated by using the Student’s t-test. The results of the statistical analysis revealed an improvement in third molars position, the best results were seen in the lower third molars, in the group of patients treated with premolar extractions. PMID:23904878

  9. Periodontal regeneration of transplanted rat molars after cryopreservation.

    PubMed

    Kawasaki, Naoko; Hamamoto, Yoshioki; Nakajima, Tamio; Irie, Kazuharu; Ozawa, Hidehiro

    2004-01-01

    The effects of cryopreservation on periodontal regeneration of transplanted rat molars were investigated histologically and histochemically in rats. Bilateral first and second maxillary molars of 4-week-old Wistar rats were gently extracted and transplanted into the abdominal subcutaneous connective tissue immediately or after cryopreservation in liquid nitrogen overnight. Donor teeth were slowly frozen by a rate-controlling freezer (program freezer) using 5% dimethylsulfoxide (DMSO) and 6% hydroxyethyl starch (HES) as cryoprotectants. One-four weeks after transplantation, they were carefully excised with the surrounding tissues. Regeneration of acellular cementum, periodontal ligament, and alveolar bone were observed 2 weeks after immediate transplantation. The pulp was repaired by the ingrowth of granulation tissue from the root apex followed by the formation of calcified tissue. The regenerated periodontal ligament was positive for alkaline phosphatase (ALP). Small or mononuclear tartrate resistant acid phosphatase (TRAP) positive cells were scattered on the newly formed alveolar bone and on the hard tissue in the pulp, but there was no external or internal progressive root resorption at 4 weeks. Cryopreserved teeth had acellular cementum with a rough surface at 1 week, but with the increase of cementoblasts and the appearance of periodontal ligament and alveolar bone, the surface became smooth at 3 weeks. Epithelial rests of Malassez (ERM) also revived. After regeneration of the periodontal tissues at 4 weeks, there was no evidence of root resorption. Although the process proceeded slowly, the cryopreserved teeth showed the periodontal regeneration substantially similar to that of the immediately transplanted teeth without progressive root resorption, indicating that they could be applicable for clinical use. PMID:14693198

  10. Preparation and characterization Al3+-bentonite Turen Malang for esterification fatty acid (palmitic acid, oleic acid and linoleic acid)

    NASA Astrophysics Data System (ADS)

    Abdulloh, Abdulloh; Aminah, Nanik Siti; Triyono, Mudasir, Trisunaryanti, Wega

    2016-03-01

    Catalyst preparation and characterization of Al3+-bentonite for esterification of palmitic acid, oleic acid and linoleic acid has been done. Al3+-bentonite catalyst was prepared from natural bentonite of Turen Malang through cation exchange reaction using AlCl3 solution. The catalysts obtained were characterized by XRD, XRF, pyridine-FTIR and surface area analyser using the BET method. Catalyst activity test of Al3+-bentonite for esterification reaction was done at 65°C using molar ratio of metanol-fatty acid of 30:1 and 0.25 g of Al3+-bentonite catalyst for the period of ½, 1, 2, 3, 4 and 5 hours. Based on the characterization results, the Al3+-bentonite Turen Malang catalyst has a d-spacing of 15.63 Ǻ, acid sites of Brönsted and Lewis respectively of 230.79 µmol/g and 99.39 µmol/g, surface area of 507.3 m2/g and the average of radius pore of 20.09 Å. GC-MS analysis results of the oil phase after esterification reaction showed the formation of biodiesel (FAME: Fatty acid methyl ester), namely methyl palmitate, methyl oleate and methyl linoleate. The number of conversions resulted in esterification reaction using Al3+-bentonite Turen Malang catalyst was 74.61%, 37.75%, and 20, 93% for the esterification of palmitic acid, oleic acid and linoleic acid respectively.

  11. Source inference of exogenous gamma-hydroxybutyric acid (GHB) administered to humans by means of carbon isotopic ratio analysis: novel perspectives regarding forensic investigation and intelligence issues.

    PubMed

    Marclay, François; Saudan, Christophe; Vienne, Julie; Tafti, Mehdi; Saugy, Martial

    2011-05-01

    γ-Hydroxybutyric acid (GHB) is an endogenous short-chain fatty acid popular as a recreational drug due to sedative and euphoric effects, but also often implicated in drug-facilitated sexual assaults owing to disinhibition and amnesic properties. Whilst discrimination between endogenous and exogenous GHB as required in intoxication cases may be achieved by the determination of the carbon isotope content, such information has not yet been exploited to answer source inference questions of forensic investigation and intelligence interests. However, potential isotopic fractionation effects occurring through the whole metabolism of GHB may be a major concern in this regard. Thus, urine specimens from six healthy male volunteers who ingested prescription GHB sodium salt, marketed as Xyrem(®), were analysed by means of gas chromatography/combustion/isotope ratio mass spectrometry to assess this particular topic. A very narrow range of δ(13)C values, spreading from -24.81‰ to -25.06‰, was observed, whilst mean δ(13)C value of Xyrem(®) corresponded to -24.99‰. Since urine samples and prescription drug could not be distinguished by means of statistical analysis, carbon isotopic effects and subsequent influence on δ(13)C values through GHB metabolism as a whole could be ruled out. Thus, a link between GHB as a raw matrix and found in a biological fluid may be established, bringing relevant information regarding source inference evaluation. Therefore, this study supports a diversified scope of exploitation for stable isotopes characterized in biological matrices from investigations on intoxication cases to drug intelligence programmes. PMID:21455654

  12. High aspect ratio nanoimprinted grooves of poly(lactic-co-glycolic acid) control the length and direction of retraction fibers during fibroblast cell division.

    PubMed

    Su, Yi-Hsuan; Chiang, Po-Chieh; Cheng, Li-Jing; Lee, Chau-Hwang; Swami, Nathan S; Chou, Chia-Fu

    2015-01-01

    Retraction fibers (RFs) determine orientation of the cell division axis and guide the spreading of daughter cells. Long and unidirectional RFs, which are especially apparent during mitosis of cells in three-dimensional (3D) environments, enable improved control over cell fate, following division. However, 3D gel environments lack the cues necessary for predetermining the orientation of RFs to direct tissue architecture. While patterning of focal adhesion regions by microcontact printing can determine orientation of the RFs through enhancing focal adhesion numbers along particular directions, the RFs remain short due to the two-dimensional culture environment. Herein, the authors demonstrate that nanoimprinted grooves of polylactic acid glycolic acid (PLGA) with a high aspect ratio (A.R. of 2.0) can provide the cues necessary to control the direction of RFs, as well as enable the maintenance of long and unidirectional RFs as observed within 3D cultures, while the same is not possible with PLGA grooves of lower A.R. (1.0 or lower). Based on enhanced levels of contact guidance of premitotic fibroblast protrusions at high A.R. grooves and deeper levels of focal adhesion due to filopodia extensions into these grooves, it is suggested that submicron (800 nm width) PLGA grooves with A.R. of 2 are capable of supporting mechanical forces from cell protrusions to a greater depth, thereby enabling the maintenance of the protrusions as long and unidirectional RFs during cell division. Given the scalability and versatility of nanoimprint techniques, the authors envision a platform for designing nanostructures to direct tissue regeneration and developmental biology. PMID:26652706

  13. Lipid Biomarkers and Carbon Isotope Ratios of Lipids Isolated from Acid Mine Drainage Biofilms: Dual Biosignatures for Eukaryotic Evolution and Oxygenation of Primitive Earth

    NASA Astrophysics Data System (ADS)

    Dasgupta, S.; Fang, J.; Zhang, L.; Li, J.

    2012-12-01

    Lipid analysis and carbon isotope ratios (δ13C) of lipids in biofilms in an acid mine drainage site (AMD) site in western Indiana revealed unique biogeochemical signatures of microeukaryotes, never recorded before. Dominance of photosynthetic microeukaryote Euglena was indicated by the detection of abundant phytadiene, phytol, phytanol, polyunsaturated n-alkenes, polyunsaturated fatty acids, short-chain (C25-32) wax esters (WE), ergosterol, and tocopherols. The WE were probably synthesized in mitochondria under anoxic conditions by the reverse β-oxidation pathway, whereas the sterols (ergosterol and ergosta-7,22-dien-3β-ol) were likely synthesized in the cytosol in the presence of molecular oxygen. The dual aerobic and anaerobic biosynthetic pathways of Euglena may be a response to survive the recurring anoxic and oxic conditions in primitive Earth, whereby microeukaryotes retained this mechanism of conserved compartmentalization within their physiology to evolve and diversify in extreme conditions. Hydrocarbons, including n-alkenes, phytadienes, and wax esters showed heavy δ13C values than usual. The primary cause for the 13C-enrichment can be attributed to a CO2-limiting system that exists in the AMD, which is further regulated by the pH of the AMD. Floating biofilms BF2, 4, and 6 showed more depleted δ13C values for phytadienes and n-alkenes (average of -23.6‰) as compared to benthic biofilm BF5 (average of -20.8‰), indicating that physiology plays an important role in isotopic discrimination. 13C-enriched values of the esters could result from kinetic isotope effects at two branch points (pyruvate and/or acetyl CoA) in the biosynthetic pathway. Our understanding of biogeochemical conditions in this AMD environment would allow us to identify unique sets of biosignatures that can act as a proxy in deciphering the links between eukaryotic evolutions, oxygenation of the early atmosphere, formation of BIF, and possibly iron-rich extraterrestrial

  14. Magnesium oxide-supported ziegler catalyst modified with acid and higher alkanol, and process for preparing narrow MWD HDPE

    SciTech Connect

    Hsieh, J.T.T.

    1989-09-05

    This patent describes a coordination-catalyst suitable for the polymerization of olefins. It comprises a titanium component and an organoaluminum compound reducing agent on a magnesium oxide support which has been pre-treated with a molar deficiency of a carboxylic acid with respect to the magnesium oxide support. The titanium component is the reaction product of an alkanol having 5 to 12 carbon atoms and TiCl/sub 4/ with the molar ratio of the alkanol to the TiCl/sub 4/ being about 0.5 to about 1.5.

  15. Autotransplantation of Mandibular Third Molar: A Case Report

    PubMed Central

    Ravi kumar, Pabbati; Jyothi, Mandava; Sirisha, Kantheti; Racca, Khushboo; Uma, Chalasani

    2012-01-01

    Autogenous transplantation is a feasible, fast, and economical option for the treatment of nonsalvageable teeth when a suitable donor tooth is available. This paper presents successful autotransplantation of a mature mandibular left third molar (38) without anatomical variances is used to replace a mandibular left second molar (37). The mandibular second molar was nonrestorable due to extensive root caries and resorption of distal root. After extraction of mandibular second and third molars, root canal therapy was done for the third molar extraorally, and the tooth was reimplanted into the extracted socket of second molar site. After one year, clinical and radiographic examination revealed satisfactory outcome with no signs or symptoms suggestive of pathology. In selected cases, autogenous tooth transplantation, even after complete root formation of the donor tooth, may be considered as a practical treatment alternative to conventional prosthetic rehabilitation or implant treatment. PMID:23346422

  16. Intrusion of overerupted molars by corticotomy and orthodontic skeletal anchorage.

    PubMed

    Moon, Cheol-Hyun; Wee, Jin-Uk; Lee, Hyun-Sun

    2007-11-01

    This article describes the orthodontic treatment of a 26-year-old female patient with overerupted left maxillary molar teeth. Her chief complaint was that the maxillary left first and the second molar intruded into the space required for the mandibular left first and the second molars, preventing prosthodontic treatment. The authors performed a corticotomy and used orthodontic skeletal anchorage with a miniplate and orthodontic miniscrews with a head modified to provide a specially designed hook. With this approach, they were able to achieve a sufficient amount of molar intrusion without discomfort, root resorption, or extrusion of the adjacent teeth. The first molar was intruded 3.0 mm and second molar was intruded 3.5 mm during 2 months of treatment. These results have been maintained for 11 months. PMID:18004918

  17. Molar mass distribution and solubility modeling of asphaltenes

    SciTech Connect

    Yarranton, H.W.; Masliyah, J.H.

    1996-12-01

    Attempts to model asphaltene solubility with Scatchard-Hildebrand theory were hampered by uncertainty in molar volume and solubility parameter distribution within the asphaltenes. By considering asphaltenes as a series of polyaromatic hydrocarbons with randomly distributed associated functional groups, molar volume and solubility parameter distributions are calculated from experimental measurements of molar mass and density. The molar mass distribution of Athabasca asphaltenes is determined from interfacial tension and vapor pressure osmometry measurements together with plasma desorption mass spectrometry determinations from the literature. Asphaltene densities are calculated indirectly from mixtures of known concentration of asphaltene in toluene. Asphaltene density, molar volume, and solubility parameter are correlated with molar mass. Solid-liquid equilibrium calculations based on solubility theory and the asphaltene property correlations successfully predict experimental data for both the precipitation point and the amount of precipitated asphaltenes in toluene-hexane solvent mixtures.

  18. Synthesis of monoacylglycerol containing pinolenic acid via stepwise esterification using a cold active lipase.

    PubMed

    Pyo, Young-Gil; Hong, Seung In; Kim, Yangha; Kim, Byung Hee; Kim, In-Hwan

    2012-01-01

    High purity monoacylglycerol (MAG) containing pinolenic acid was synthesized via stepwise esterification of glycerol and fatty acids from pine nut oil using a cold active lipase from Penicillium camembertii as a biocatalyst. Effects of temperature, molar ratio, water content, enzyme loading, and vacuum on the synthesis of MAG by lipase-catalyzed esterification of glycerol and fatty acid from pine nut oil were investigated. Diacylglycerol (DAG) as well as MAG increased significantly when temperature was increased from 20 to 40 °C. At a molar ratio of 1:1, MAG content decreased because of the significant increase in DAG content. Water has a profound influence on both MAG and DAG content through the entire course of reaction. The reaction rate increased significantly as enzyme loading increased up to 600 units. Vacuum was an effective method to reduce DAG content. The optimum temperature, molar ratio, water content, enzyme loading, vacuum, and reaction time were 20 °C, 1:5 (fatty acid to glycerol), 2%, 600 units, 5 torr, and 24 h, respectively. MAG content further increased via lipase-catalyzed second step esterification at subzero temperature. P. camembertii lipase exhibited esterification activity up to -30 °C. PMID:22753389

  19. Ab initio molar volumes and Gaussian radii.

    PubMed

    Parsons, Drew F; Ninham, Barry W

    2009-02-12

    Ab initio molar volumes are calculated and used to derive radii for ions and neutral molecules using a spatially diffuse model of the electron distribution with Gaussian spread. The Gaussian radii obtained can be used for computation of nonelectrostatic ion-ion dispersion forces that underlie Hofmeister specific ion effects. Equivalent hard-sphere radii are also derived, and these are in reasonable agreement with crystalline ionic radii. The Born electrostatic self-energy is derived for a Gaussian model of the electronic charge distribution. It is shown that the ionic volumes used in electrostatic calculations of strongly hydrated cosmotropic ions ought best to include the first hydration shell. Ionic volumes for weakly hydrated chaotropic metal cations should exclude electron overlap (in electrostatic calculations). Spherical radii are calculated as well as nonisotropic ellipsoidal radii for nonspherical ions, via their nonisotropic static polarizability tensors. PMID:19140766

  20. Lipase-catalyzed synthesis of fatty acid amide (erucamide) using fatty acid and urea.

    PubMed

    Awasthi, Neeraj Praphulla; Singh, R P

    2007-01-01

    Ammonolysis of fatty acids to the corresponding fatty acid amides is efficiently catalysed by Candida antartica lipase (Novozym 435). In the present paper lipase-catalysed synthesis of erucamide by ammonolysis of erucic acid and urea in organic solvent medium was studied and optimal conditions for fatty amides synthesis were established. In this process erucic acid gave 88.74 % pure erucamide after 48 hour and 250 rpm at 60 degrees C with 1:4 molar ratio of erucic acid and urea, the organic solvent media is 50 ml tert-butyl alcohol (2-methyl-2-propanol). This process for synthesis is economical as we used urea in place of ammonia or other amidation reactant at atmospheric pressure. The amount of catalyst used is 3 %. PMID:17898456

  1. Removal of free fatty acid in Palm Fatty Acid Distillate using sulfonated carbon catalyst derived from biomass wastefor biodiesel production

    NASA Astrophysics Data System (ADS)

    Hidayat, Arif; Rochmadi; Wijaya, Karna; Budiman, Arief

    2016-01-01

    In this research, the esterification of PFAD using the sulfonatedcoconut shell biochar catalyst was studied. Carbon solid catalysts were prepared by a sulfonation of carbonized coconut shells. The performances of the catalysts were evaluated in terms of the reaction temperatures, the molar ratios of methanol to PFAD, the catalyst loading and the reaction times. The reusability of the solid acid carbon catalysts was also studied in this work. The results indicated that the FFA conversion was significantly increased with increasing catalyst loading and reaction times. It can be concluded that the optimal conditions were an PFAD to methanol molar ratio of 1:12, the amount of catalyst of 10%w, and reaction temperature of 60oC.At this optimum condition, the conversion to biodieselreached 88%.

  2. Impact of different ratios of Omega-6 polyundaturated fatty acids to eicosapentaenoic acid (EPA) plus docosahexaenoic acid (DHA) on atherosclerotic lesion formation and inflammatory factors in the LDL receptor knockout mouse

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective was to assess the effect of different ratios of omega-6 to EPA plus DHA on atherosclerotic lesion formation and plasma inflammatory markers in LDLr-/- mice. Mice (n=10/group) were fed the following diets for 32 weeks: high fat (20% w/w) without EPA and DHA (HF omega-6), and high fat wi...

  3. Autotransplantation of a Buccally Erupted Matured Mandibular Third Molar to Replace a Grossly Decayed Second Molar.

    PubMed

    Yadav, Sukhwant Singh; Bodh, Ranjeet; Kaushik, Aishvarya; Talwar, Sangeeta

    2016-02-01

    Autotransplantation can be a treatment option for tooth loss as an alternative to fixed or implant-supported prostheses. It has predictable results comparable to implants, with reported success rates often greater than 90%. In present case, buccally erupted matured third molar was autotransplanted in extraction socket of grossly carious mandibular second molar. The tooth was splinted for 1 week followed by root canal treatment. After 12 months follow up, tooth was in perfect state of function and aesthetic with healthy periapical and periodontal architecture. High success rate was found in immature tooth transplantation in previous case reports. This case report describes that even matured tooth can also be used as donor if atraumatic extraction is possible and endodontic treatment is well performed. PMID:27042593

  4. Autotransplantation of a Buccally Erupted Matured Mandibular Third Molar to Replace a Grossly Decayed Second Molar

    PubMed Central

    Bodh, Ranjeet; Kaushik, Aishvarya; Talwar, Sangeeta

    2016-01-01

    Autotransplantation can be a treatment option for tooth loss as an alternative to fixed or implant-supported prostheses. It has predictable results comparable to implants, with reported success rates often greater than 90%. In present case, buccally erupted matured third molar was autotransplanted in extraction socket of grossly carious mandibular second molar. The tooth was splinted for 1 week followed by root canal treatment. After 12 months follow up, tooth was in perfect state of function and aesthetic with healthy periapical and periodontal architecture. High success rate was found in immature tooth transplantation in previous case reports. This case report describes that even matured tooth can also be used as donor if atraumatic extraction is possible and endodontic treatment is well performed. PMID:27042593

  5. Anchorage reinforcement with a fixed functional appliance during protraction of the mandibular second molars into the first molar extraction sites.

    PubMed

    Chhibber, Aditya; Upadhyay, Madhur

    2015-07-01

    Protraction of posterior teeth into edentulous spaces is a challenge. This report describes the treatment of a 19-year-old woman with missing mandibular first molars owing to caries. A fixed functional appliance was used for anchorage reinforcement during mandibular second molar protraction. Eight millimeters of bilateral protraction was done with bodily mesial movement of the molars and no lingual tipping of the incisors. PMID:26124039

  6. Continuous lipase-catalyzed esterification of soybean fatty acids under ultrasound irradiation.

    PubMed

    Trentin, Claudia M; Scherer, Robison P; Dalla Rosa, C; Treichel, H; Oliveira, D; Oliveira, J Vladimir

    2014-05-01

    This work investigates the continuous production of alkyl esters from soybean fatty acid (FA) charges using immobilized Novozym 435 as catalyst. The experiments were performed in a packed-bed bioreactor evaluating the effects of FA charge to alcohol (methanol and ethanol) molar ratio, from 1:1 to 1:6, substrate flow rate in the range of 0.5-2.5 mL/min and output irradiation power up to 154 W, at fixed temperature of 65 °C, on the reaction conversion. Results showed that almost complete conversions to fatty acids ethyl esters were achieved at mild ultrasonic power (61.6 W), FA to ethanol molar ratio of 1:6, operating temperature (65 °C) and remained nearly constant for long-term reactions without negligible enzyme activity losses. PMID:24078183

  7. Densities, Excess Molar Volumes, and Thermal Expansion Coefficients of Aqueous Aminoethylethanolamine Solutions at Temperatures from 283.15 to 343.15 K.

    PubMed

    Stec, Marcin; Tatarczuk, Adam; Spiewak, Dariusz; Wilk, Andrzej

    2014-01-01

    The densities of aqueous mixtures of aminoethylethanolamine (CAS #000111-41-1) were measured over the entire compositional range at temperatures of 283.15-343.15 K. The results of these measurements were used to calculate excess molar volumes and isobaric thermal expansion coefficients, and partial molar and apparent molar volumes and excess isobaric thermal expansion coefficients were subsequently derived. The excess molar volumes were correlated as a function of the mole fraction using the Redlich-Kister equation. Temperature dependences of the Redlich-Kister coefficients are also presented. The partial molar volumes at infinite dilution of AEEA in water were determined using two different methods. In addition, the solution density was correlated using a Joubian-Acree model. Aqueous solutions of AEEA exhibit similar properties to the aqueous solutions of other alkanolamines (like monoethanolamine) used in acid gas sweetening. PMID:24899753

  8. Process for the extended use of strip acid employed in the reclamation of battery acid fluid from expanded lead-acid batteries

    SciTech Connect

    Spitz, R.A.; Bricker, M.

    1991-04-23

    This patent describes a method for recycling contaminated sulfuric acid from lead acid batteries to reclaimed sulfuric acid for reuse in the batteries by removing contaminating iron impurities. It includes diluting the contaminated sulfuric acid to a concentration between 150 and 230 grams per liter; filtering the sulfuric acid through a first filter means to remove solid impurities; oxidizing the sulfuric acid to assure that the iron contaminants are substantially in a ferric form; removing the iron contaminants from the sulfuric acid through liquid-liquid extracting using an extraction agent comprising mixture of a mono- or di-alkyl phosphoric acid and a metal chelation collector selected from the group consisting of a 8- hydroxyquinoline substituted in the No. 7 position with a long chain aliphatic hydrocarbon radical and an oil-soluble 2-hydroxy benzophenoneoxime, a modifier which maintains solubility of the phosphoric acid and the metal chelation collector and enhances phase disengagement, and a water immiscible carrier, the molar ratio of the 8-hydroxyquinoline and the phosphoric acid being between 1:1::1:4, respectively; wherein the ratio of extraction agent to water immiscible carrier is greater than 10:90; the extraction performed at a volumetric ratio between 4:1::1:4, and repeated until the contaminating iron impurities are substantially reduced.

  9. α-hydroxy acids mediated synthesis of hollow silver nanoshells and their optical properties

    NASA Astrophysics Data System (ADS)

    Dadhich, B.; Saha, A.; Priyam, A.

    2016-05-01

    The α-hydroxy-acids (i.e. glycolic, malic, citric) plays crucial role in the formation of hollow silver nanoshells and in its plasmonic properties. The SPR peak varied in a wide range from 400-527 nm with variation in chain length and molar concentration or ratio of the acids. The stability was also affected by chain length. Zeta potential analyzed for the stability of hollow silver nanoshells (HAgNS). The hollow structure of these nanocrystals with aspect ratio (Outer diameter/ shell thickness) 2 to 5 is confirmed by HR-TEM.

  10. Ileal Endogenous Amino Acid Flow Response to Nitrogen-free Diets with Differing Ratios of Corn Starch to Dextrose in Pigs

    PubMed Central

    Kong, C.; Ragland, D.; Adeola, O.

    2014-01-01

    The objective of this study was to determine the responses in the digestibility of dry matter (DM) and amino acid (AA) composition of ileal endogenous flow (IEF) of pigs (initial body weight, 69.1±6.46 kg) fed N-free diets (NFD) formulated with different ratios of corn starch to dextrose. Fifteen pigs fitted with a T-cannula at the distal ileum were fed 5 diets according to a triplicated 5×2 incomplete Latin-square design. Each period consisted of a 5-d adjustment period and 2 d of ileal digesta collection for 12 h on each of d 6 and 7 and between each period, there was a 5-d recovery period to avoid abnormal weight loss. The ratios of corn starch to dextrose investigated were 0:879, 293:586, 586:293, 779:100, and 879:0 for diet numbers 1, 2, 3, 4 and 5, respectively, and chromic oxide (5 g/kg) was used as an indigestible index. Ileal DM digestibility was greater in Diet 1 than that in Diet 4 (89.5% vs 87.3%, p<0.01) but they were not different from Diet 2, 3, or 5. The IEF for most of indispensable AA were not different among diets with the exception of Met, in which a lack of corn starch or dextrose gave lower (p = 0.028) IEF of Met than diets containing corn starch and dextrose. Likewise, the dispensable AA and total AA in the IEF did not differ among diets. The respective IEF of AA (mg/kg of dry matter intake) in pigs fed Diets 1, 2, 3, 4, or 5 were 301, 434, 377, 477,or 365 for Lys, 61, 89, 71, 87, or 61 for Met, and 477, 590, 472, 520, or 436 for Thr. Proline was the most abundant AA in the IEF followed by Gly, Glu, and Asp and together accounted for approximately 50% of the total ileal AA flows of pigs fed NFD. In conclusion, the variation in proportion of corn starch and dextrose in a NFD does not largely affect estimates of IEF of N and AA for growing-finishing pigs. PMID:25083106

  11. Embryo development and sex ratio of in vitro-produced porcine embryos are affected by the energy substrate and hyaluronic acid added to the culture medium.

    PubMed

    Torner, Eva; Bussalleu, Eva; Briz, M Dolors; Yeste, Marc; Bonet, Sergi

    2014-01-01

    In the present study, the effects of replacing glucose with pyruvate-lactate and supplementing these in vitro culture (IVC) media with hyaluronic acid (HA) on porcine embryo development and sex ratio were examined. The in vitro-produced (IVP) porcine embryos were cultured in NCSU-23 medium with 0.0, 0.5 or 1.0mgmL(-1) HA, and with either 5.55mM glucose (IVC-Glu) or pyruvate (0.17mM)-lactate (2.73mM) from 0 to 48h post insemination (h.p.i.) and then with glucose from 48 to 168h.p.i. (IVC-PL). Those embryos cultured with IVC-PL had significantly higher blastocyst rates (23.7±1.5%) than those cultured with IVC-Glu (14.27±2.75%). At 1.0mgmL(-1), HA tended to skew the sex ratio of blastocysts towards males in those embryos cultured in IVC-PL, and led to a significant decrease in the blastocyst rate compared with embryos cultured in the presence of 0.5 and 0.0mgmL(-1) HA and IVC-Glu (4.28±0.28% vs 11.01±1.42% and 10.14±2.77%, respectively) and IVC-PL (14.37±1.35% vs 20.96±2.85% and 22.99±1.39%, respectively). In contrast, there were no significant differences in the total cell number per blastocyst or in apoptosis rates. In conclusion, pyruvate and lactate were the preferred energy substrates in the early stages of IVP porcine embryos. Moreover, 1.0mgmL(-1) HA significantly decreased the percentage of blastocyst rates in both the IVC-Glu and IVC-PL groups, but only by a preferential loss of female embryos for those cultured in IVC-PL. PMID:23657201

  12. Chemical characterization of the acid alteration of diesel fuel: Non-targeted analysis by two-dimensional gas chromatography coupled with time-of-flight mass spectrometry with tile-based Fisher ratio and combinatorial threshold determination.

    PubMed

    Parsons, Brendon A; Pinkerton, David K; Wright, Bob W; Synovec, Robert E

    2016-04-01

    The illicit chemical alteration of petroleum fuels is of keen interest, particularly to regulatory agencies that set fuel specifications, or taxes/credits based on those specifications. One type of alteration is the reaction of diesel fuel with concentrated sulfuric acid. Such reactions are known to subtly alter the chemical composition of the fuel, particularly the aromatic species native to the fuel. Comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC×GC-TOFMS) is well suited for the analysis of diesel fuel, but may provide the analyst with an overwhelming amount of data, particularly in sample-class comparison experiments comprised of many samples. Tile-based Fisher-ratio (F-ratio) analysis reduces the abundance of data in a GC×GC-TOFMS experiment to only the peaks which significantly distinguish the unaltered and acid altered sample classes. Three samples of diesel fuel from differently branded filling stations were each altered to discover chemical features, i.e., analyte peaks, which were consistently changed by the acid reaction. Using different fuels prioritizes the discovery of features likely to be robust to the variation present between fuel samples and may consequently be useful in determining whether an unknown sample has been acid altered. The subsequent analysis confirmed that aromatic species are removed by the acid alteration, with the degree of removal consistent with predicted reactivity toward electrophilic aromatic sulfonation. Additionally, we observed that alkenes and alkynes were also removed from the fuel, and that sulfur dioxide or compounds that degrade to sulfur dioxide are generated by the acid alteration. In addition to applying the previously reported tile-based F-ratio method, this report also expands null distribution analysis to algorithmically determine an F-ratio threshold to confidently select only the features which are sufficiently class-distinguishing. When applied to the acid

  13. [Distalization of the upper second molar: clinical case].

    PubMed

    Castaldo, A; Blasi, S; Vettese, P

    1991-01-01

    The Authors showed a clinical case in which has been put on a distalizing system together with a palatal bar between the first upper molars, a sectional placed between the first and the second molar and a 100 g precalibrated Sentalloy coil. PMID:1784297

  14. Mandibular third molar autotransplantation--literature review with clinical cases.

    PubMed

    Mendes, Rui Amaral; Rocha, Germano

    2004-12-01

    Autotransplantation of mandibular third molars in a precocious phase of development is indicated when a substitute for adjacent compromised or missing molars is needed, and when mesial movements of the posterior teeth, the resultant loss of space, and overeruption of opposing teeth and consequent changes in the occlusion must be avoided. Provided that the apices of the mandibular third molar are immature, the immediate replacement of a lost or compromised tooth usually ensures a good outcome. Transplantation of third molars helps to maintain alveolar bone and enables endosseous implantation without requiring bone regeneration. We present examples of transplantation of mandibular third molars and review the factors that affect the success or failure of this procedure, such as atraumatic extraction and adequate immobilization of the transplanted tooth and root development after transplantation. Sex or age seem to have no effect on the final outcome. PMID:15588551

  15. Chemical characterization of high-molar-mass fractions in a Norway spruce knotwood ethanol extract.

    PubMed

    Smeds, Annika I; Eklund, Patrik C; Willför, Stefan M

    2016-10-01

    The low-molar-mass (LMM) fraction, only, i.e., the GC-eluting compounds, which are mainly lignans, has been characterized in Norway spruce knotwood hydrophilic extracts previously. Of this fraction, many lignans and sesquilignans and all GC peaks supposedly representing dilignans remain unidentified. In this work, dilignans and the GC non-eluting compounds (the high-molar mass fractions, HMM) were characterized in a 7-hydroxymatairesinol-reduced knotwood ethanol extract of Norway spruce by using several fractionation and analytical techniques. A methyl tert-butyl ether (MTBE) insoluble fraction of the extract contained mainly HMM material, of which the main part was shown to consist of lignan oligomers. The oligolignans (with a molar mass up to approximately 3700 Da) seemed to be linked by 55' bonds, some of them containing one or two guaiacylglycerol ether units linked to the lignan by βO4 or β5 bonds. Several oligolignans were identified or tentatively identified. The MTBE soluble fraction, which accounted for the major part (81%) of the extract, contained mainly LMM material (lignans, sesqui- and dilignans). The part of the HMM material in the MTBE soluble fraction that was easily isolable (2%) seemed to contain polymers of fatty acids and alcohols, resin acids, and sterols. PMID:27256310

  16. Nonsurgical Endodontic Management of a Molar-Incisor Malformation-affected Mandibular First Molar: A Case Report.

    PubMed

    Yue, Wonyoung; Kim, Euiseong

    2016-04-01

    A molar-incisor malformation (MIM) is a newly reported type of dental anomaly that involves a characteristic root malformation in permanent first molars and deciduous second molars and a crown defect in permanent central incisors. This case report describes a nonsurgical root canal treatment of a MIM-affected molar by aid of a reformatted axial view of the tooth cone-beam computed tomography (CBCT). A MIM-affected molar has calcified canal orifices and a few immature accessory furcal canals. Conventional root canal treatment with the aid of CBCT followed by resin restoration was performed on the tooth. The malformed roots of MIM teeth generally make it difficult to apply conventional endodontic treatment; however, it was possible to do with the aid of the reformatted axial view of the CBCT. PMID:26706790

  17. Influence of acid precursors on physicochemical properties of nanosized titania synthesized by thermal-hydrolysis method

    SciTech Connect

    Rajesh, B.; Sasirekha, N.R.; Chen, Y.-W.

    2008-03-04

    The influence of nature and concentration of acid species on surface morphology and physicochemical properties of titania particles synthesized by direct thermal hydrolysis of titanium tetrachloride was investigated. The acids used were hydrochloric acid, nitric acid, sulfuric acid, and perchloric acid with a concentration of 3 M. Thermal hydrolysis of titanium tetrachloride in hydrochloric acid and perchloric acid with molar ratios of [H{sup +}]/[Ti{sup 4+}] = 0.5, 1.0, 1.5, and 2.0, respectively, was used to study the effect of acid concentration. The synthesized materials were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, dynamic light scattering, and thermogravimetric analysis. Characterization of the samples by X-ray diffraction studies revealed the influence of acid species on the phase transformation of titania. Samples prepared by hydrochloric acid, nitric acid, and perchloric acid formed rutile phase with rhombus primary particles, while sulfuric acid resulted in anatase phase with flake-shaped primary particles. Transmission electron microscopy and dynamic light scattering results confirmed the nanosized titania particles and the agglomeration of primary particles to form secondary particles in spherical shape. The particle size of titania prepared using perchloric acid was smaller than those prepared with other acid sources. A direct correlation between [H{sup +}]/[Ti{sup 4+}] ratio and particle size of titania was observed.

  18. Replacement of a first molar and 3 second molars by the mesial inclination of 4 impacted third molars in an adult with a Class II Division 1 malocclusion.

    PubMed

    Tomonari, Hiroshi; Yagi, Takakazu; Kuninori, Takaharu; Ikemori, Takahiro; Miyawaki, Shouichi

    2015-06-01

    This case report presents the successful replacement of 1 first molar and 3 second molars by the mesial inclination of 4 impacted third molars. A woman, 23 years 6 months old, had a chief complaint of crowding of her anterior teeth and linguoclination of a second molar on the left side. The panoramic radiographic images showed that the maxillary and mandibular third molars on both sides were impacted. Root resorption on the distal surfaces of the maxillary second molars was suspected. The patient was given a diagnosis of Angle Class II Division 1 malocclusion with severe crowding of the anterior teeth and 4 impacted third molars. After we extracted the treated maxillary second premolars and the second molars on both sides, the treated mandibular second premolar and the second molar on the left side, and the root canal-filled mandibular first molar on the right side, the 4 impacted third molars were uprighted and formed part of the posterior functional occlusion. The total active treatment period was 39 months. The maxillary and mandibular third molars on both sides successfully replaced the first and second molars. The replacement of a damaged molar by an impacted third molar is a useful treatment option for using sound teeth. PMID:26038080

  19. Differential Ratios of Omega Fatty Acids (AA/EPA+DHA) Modulate Growth, Lipid Peroxidation and Expression of Tumor Regulatory MARBPs in Breast Cancer Cell Lines MCF7 and MDA-MB-231

    PubMed Central

    Mansara, Prakash P.; Deshpande, Rashmi A.; Vaidya, Milind M.; Kaul-Ghanekar, Ruchika

    2015-01-01

    Omega 3 (n3) and Omega 6 (n6) polyunsaturated fatty acids (PUFAs) have been reported to exhibit opposing roles in cancer progression. Our objective was to determine whether different ratios of n6/n3 (AA/EPA+DHA) FAs could modulate the cell viability, lipid peroxidation, total cellular fatty acid composition and expression of tumor regulatory Matrix Attachment Region binding proteins (MARBPs) in breast cancer cell lines and in non-cancerous, MCF10A cells. Low ratios of n6/n3 (1:2.5, 1:4, 1:5, 1:10) FA decreased the viability and growth of MDA-MB-231 and MCF7 significantly compared to the non-cancerous cells (MCF10A). Contrarily, higher n6/n3 FA (2.5:1, 4:1, 5:1, 10:1) decreased the survival of both the cancerous and non-cancerous cell types. Lower ratios of n6/n3 selectively induced LPO in the breast cancer cells whereas the higher ratios induced in both cancerous and non-cancerous cell types. Interestingly, compared to higher n6/n3 FA ratios, lower ratios increased the expression of tumor suppressor MARBP, SMAR1 and decreased the expression of tumor activator Cux/CDP in both breast cancer and non-cancerous, MCF10A cells. Low n6/n3 FAs significantly increased SMAR1 expression which resulted into activation of p21WAF1/CIP1 in MDA-MB-231 and MCF7, the increase being ratio dependent in MDA-MB-231. These results suggest that increased intake of n3 fatty acids in our diet could help both in the prevention as well as management of breast cancer. PMID:26325577

  20. Economic and health implications of routine CBCT examination before surgical removal of the mandibular third molar in the Danish population

    PubMed Central

    Olsen, K R; Matzen, L H; Vaeth, M; Wenzel, A

    2015-01-01

    Objectives: This epidemiological study aimed to analyse economical and societal consequences in Denmark if CBCT is used routinely as a diagnostic method before removal of the mandibular third molar. Furthermore, the aim was to calculate the excess cancer incidence from this practice. Methods: 17 representative dental clinics in the regions of Denmark were visited by two observers, who registered the total number of patients in each clinic, the number of removed mandibular third molars from patients' files together with the age and gender of these patients. The data were collected from 2008 to 2014. The total number of removed mandibular third molars in Denmark each year was derived from the collected data and information on patients' contacts with dentists from Statistics Denmark as a sum of contributions from each region. The contribution of a region was obtained as the number of removed mandibular third molars in the selected clinics in the region times the ratio of the number of patients in the selected clinics in the region to the total number of patients with contact to a general practitioner in the region in 2011. Existing knowledge on the costs for panoramic and CBCT imaging was used to calculate total costs. The cancer incidence was calculated from lifetime attributable risk curves based on linear risk assumptions. Results: The selected clinics included 109,686 patients, and 1369 mandibular third molars had been surgically removed. Using data from Statistics Denmark gave an estimated annual number of removed mandibular third molars of 36,882 at a total cost of €6,633,400. The additional cancer incidence was estimated to be approximately 0.46 per year. Conclusions: The data should be used in a cost-effectiveness analysis of the clinical efficacy of CBCT imaging before removal of mandibular third molars. PMID:25785820

  1. Modification of uprighting spring for derotation of second molars.

    PubMed

    Mallikarjun, Vankre; Rachala, Madhukar Reddy; Aileni, Kaladhar Reddy; Jaipal, Pyata Reddy

    2013-01-01

    One of the most efficient ways for the correction of rotated upper molars is derotation with a transpalatal arch, but this appliance is usually favourable when the need for correction is same on both sides of the dental arch. Derotation of unilateral upper second molar is a difficult task, especially when there is no accessible tooth/ any attachment is available distal to it for the application of couple forces. We have designed a modification of uprighting spring which is far more convenient than using the conventional method of TPA for derotation of unilateral upper second molar. PMID:24640073

  2. Molar heat capacity and entropy of calcium metal

    USGS Publications Warehouse

    Hemingway, B.S.; Robie, R.A.; Chase, M.W.

    1997-01-01

    The heat capacity of calcium has been measured at 85 mean temperatures between T ??? 8 K and T ??? 369 K using an adiabatically-shielded calorimeter in an intermittent heating mode. At T = 298.15 K, the recommended values for the molar heat capacity, molar entropy, and molar enthalpy increment referred to T = 0 are (25.77 ?? 0.08) J??K-1??mol-1, (42.90 ?? 0.11) J??K-1??mol-1, and (5811 ?? 12) J??mol-1, respectively. The uncertainties are twice the standard deviation of the mean. ?? 1997 Academic Press Limited.

  3. Lingual Guttering Technique for Removal of Impacted Mandibular Third Molars

    PubMed Central

    Kale, Tejraj P; Pandit, Vikram S; Patil, Shankargouda; Pawar, Vivek; Shetty, Nisha

    2014-01-01

    Background: To assess the clinical feasibility of lingual bone guttering technique for surgical extraction of mandibular third molars. Materials and Methods: 20 patients with thick lingual cortical plate were included in the study. Surgical extraction of mandibular third molars by lingual bone guttering technique was performed in all the subjects. These subjects were evaluated for integrity of lingual cortical plate and sensation of lingual nerve postoperatively. Results: All extractions done by lingual bone guttering technique were clinically feasible to perform and no complications were seen. Conclusion: Lingual bone guttering technique can be used safely in extraction of mandibular third molars with thick lingual cortical plate. PMID:25214725

  4. Effects of Zeolite Structure and Si/Al Ratio on Adsorption Thermodynamics and Intrinsic Kinetics of Monomolecular Cracking and Dehydrogenation of Alkanes over Bronsted Acid Sites

    NASA Astrophysics Data System (ADS)

    Janda, Amber Leigh

    It is well known that the efficacy of acidic zeolite catalysts for the cracking of hydrocarbons originates from the shape and size of the zeolite pores. However, the mechanisms by which changes in pore structure influence cracking kinetics are not well understood or exploited. The aim of this dissertation is to use experiments and simulations to shed light on the ways by which zeolite structure and acid site location affect the apparent and intrinsic kinetics of n-alkane monomolecular cracking and dehydrogenation. In the rate-determining step of these processes, C-C or C-H bonds are cleaved catalytically by Bronsted protons. Thus, the kinetics of monomolecular activation reactions are useful for characterizing the influence of active site structural environment on catalysis. In Chapter 2, the effects of active site distribution on n-butane monomolecular activation kinetics are investigated for commercial samples of MFI having a range of the Si/Al ratio. Based on UV-visible spectroscopic analyses of (Co,Na)-MFI, it is inferred that, with increasing Al concentration, the fraction of Co---and, by extension, Bronsted protons in H-MFI---located at channel intersections increases relative to the fraction located at channels. Concurrently, the first-order rate coefficients (kapp) for cracking and dehydrogenation, the selectivity to terminal cracking versus central cracking, and the selectivity to dehydrogenation versus cracking increase. The stronger dependence of the selectivity to dehydrogenation on Al content is attributed to a product-like transition state, the stability of which is more sensitive to confinement than the stabilities of cracking transition states, which occur earlier along the reaction coordinate. For terminal cracking and dehydrogenation, the intrinsic activation entropy (DeltaS‡int ) increases with Al content, consistent with the larger dimensions of intersections relative to channels. Surprisingly, the rate of dehydrogenation is inhibited by

  5. A comparison of the effects of methylprednisolone and tenoxicam on pain, edema, and trismus after impacted lower third molar extraction

    PubMed Central

    Ilhan, Ozgur; Agacayak, Kamil Serkan; Gulsun, Belgin; Koparal, Mahmut; Gunes, Nedim

    2014-01-01

    Background The aim of the present study was to compare the effects of preemptive intravenous tenoxicam and methylprednisolone administrations on extraction of impacted third molars. Material/Methods This was a placebo-controlled, randomized, double-blind, clinical trial. A total of 60 adult patients ages 18–40 years with the complaints of impacted third molar teeth were included in the study. Results The postoperative swelling ratios (p<0.05) and pain scores (p<0.05) were significantly better in both study groups than in the control group and there was no statistically significant difference between methylprednisolone and tenoxicam groups with regards to the edema and pain relief. Conclusions Preoperative administration of 80 mg methylprednisolone achieves better control of trismus than tenoxicam without any significant differences in edema and pain control in impacted third molar teeth extraction. PMID:24473372

  6. Is Pederson Index a True Predictive Difficulty Index for Impacted Mandibular Third Molar Surgery? A Meta-analysis.

    PubMed

    Bali, Amit; Bali, Deepika; Sharma, Ashutosh; Verma, Gaurav

    2013-09-01

    The aim of this meta-analysis was to find out the clinical reliability of Pederson index in assessing the difficulty of surgery for impacted mandibular 3rd molar. The relevant articles were selected by Hand search and electronic media (Medline, Pubmed, Embase Cochrane library, ISI web of science) from Jan 2000 to Dec 2010. All the relevant articles were properly screened and findings were extracted from the articles. Pederson index had shown low sensitivity and specificity in predicting the difficulty of surgery for impacted mandibular 3rd molar. Positive and negative likelihood ratio had also shown the unreliability of Pederson index. The meta-analysis of the current literature concluded that Pederson index is not a reliable test to predict the surgical difficulty of impacted mandibular 3rd molar. PMID:24431870

  7. Molar-mass measurement of a 28Si-enriched silicon crystal for determination of the Avogadro constant

    NASA Astrophysics Data System (ADS)

    Narukawa, Tomohiro; Hioki, Akiharu; Kuramoto, Naoki; Fujii, Kenichi

    2014-06-01

    The molar mass of a 28Si-enriched crystal was measured at the National Metrology Institute of Japan to determine the Avogadro constant by the x-ray crystal density method as part of the International Avogadro Coordination project. The molar mass was determined by isotope ratio measurements using a multicollector inductively coupled plasma mass spectrometer combined with an isotope dilution technique. The 28Si-enriched crystal was dissolved in tetramethylammonium hydroxide and three different blended solutions were used to correct for mass bias in the measurement. The molar mass of the 28Si-enriched crystal was determined to be 27.976 970 09 g mol-1 with a standard uncertainty of 0.000 000 14 g mol-1. This corresponds to a relative standard uncertainty of 5.2 × 10-9. This result is consistent with measurements reported by the Physikalisch-Technische Bundesanstalt, Germany.

  8. Review of the stability of biochar in soils: predictability of O:C molar ratios

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biochar is not a structured homogeneous material; rather it possesses a range of chemical structures and a heterogeneous elemental composition. This variability is based on the conditions of pyrolysis and the biomass parent material, with biochar spanning the range of various forms of black carbon. ...

  9. Absolute silicon molar mass measurements, the Avogadro constant and the redefinition of the kilogram

    NASA Astrophysics Data System (ADS)

    Vocke, R. D., Jr.; Rabb, S. A.; Turk, G. C.

    2014-10-01

    The results of an absolute silicon molar mass determination of two independent sets of samples from the highly 28Si-enriched crystal (AVO28) produced by the International Avogadro Coordination are presented and compared with results published by the Physikalisch-Technische Bundesanstalt (PTB, Germany), the National Research Council (NRC, Canada) and the National Metrology Institute of Japan (NMIJ, Japan). This study developed and describes significant changes to the published protocols for producing absolute silicon isotope ratios. The measurements were made at very high resolution on a multi-collector inductively coupled plasma mass spectrometer using tetramethylammonium hydroxide (TMAH) to dissolve and dilute all samples. The various changes in the measurement protocol and the use of TMAH resulted in significant improvements to the silicon isotope ratio precision over previously reported measurements and in particular, the robustness of the 29Si/30Si ratio of the AVO28 material. These new results suggest that a limited isotopic variability is present in the AVO28 material. The presence of this variability is at present singular and therefore its significance is not well understood. Fortunately, its magnitude is small enough so as to have an insignificant effect on the overall uncertainty of an Avogadro constant derived from the average molar mass of all four AVO28 silicon samples measured in this study. The NIST results confirm the AVO28 molar mass values reported by PTB and NMIJ and confirm that the virtual element-isotope dilution mass spectrometry approach to calibrated absolute isotope ratio measurements developed by PTB is capable of very high precision as well as accuracy. The Avogadro constant NA and derived Planck constant h based on these measurements, together with their associated standard uncertainties, are 6.02214076(19) × 1023 mol-1 and 6.62607017(21) × 10-34 Js, respectively.

  10. Caries Management Strategies for Primary Molars

    PubMed Central

    Santamaria, R.M.; Innes, N.P.T.; Machiulskiene, V.; Evans, D.J.P.; Splieth, C.H.

    2014-01-01

    Minimal invasive approaches to managing caries, such as partial caries removal techniques, are showing increasing evidence of improved outcomes over the conventional complete caries removal. There is also increasing interest in techniques where no caries is removed. We present the 1-yr results of clinical efficacy for 3 caries management options for occlusoproximal cavitated lesions in primary molars: conventional restorations (CR; complete caries removal and compomer restoration), Hall technique (HT; no caries removal, sealing in with stainless steel crowns), and nonrestorative caries treatment (NRCT; no caries removal, opening up the cavity, teaching brushing and fluoride application). In sum, 169 children (3-8 yr old; mean, 5.56 ± 1.45 yr) were enrolled in this secondary care–based, 3-arm, parallel-group, randomized clinical trial. Treatments were carried out by specialist pediatric dentists or postgraduate trainees. One lesion per child received CR, HT, or NRCT. Outcome measures were clinical failure rates, grouped as minor failure (restoration loss/need for replacement, reversible pulpitis, caries progression, etc.) and major failure (irreversible pulpitis, abscess, etc.). There were 148 children (87.6%) with a minimum follow-up of 11 mo (mean, 12.23 ± 0.98 mo). Twenty teeth were recorded as having at least 1 minor failure: NRCT, n = 8 (5%); CR, n = 11 (7%); HT, n = 1 (1%) (p = .002, 95% CI = 0.001 to 0.003). Only the comparison between NRCT and CR showed no significant difference (p = .79, 95% CI = 0.78 to 0.80). Nine (6%) experienced at least 1 major failure: NRCT, n = 4 (2%); CR, n = 5 (3%); HT, n = 0 (0%) (p = .002, 95% CI = 0.001 to 0.003). Individual comparison of NRCT and CR showed no statistically significant difference in major failures (p = .75, 95% CI = 0.73 to 0.76). Success and failure rates were not significantly affected by pediatric dentists’ level of experience (p = .13, 95% CI = 0.12 to 0.14). The HT was significantly more successful

  11. A molar theory of reinforcement schedules

    PubMed Central

    Rachlin, Howard

    1978-01-01

    Behavior of subjects exposed to concurrent and individual interval and ratio schedules of reinforcement may be described in terms of a set of expressions relating the value of responses to their durations, a feedback equation relating reinforcement to response duration, and the assumption that subjects allocate their time among various responses so as to maximize value. PMID:16812114

  12. Seasonal and spatial variability of the organic matter-to-organic carbon mass ratios in Chinese urban organic aerosols and a first report of high correlations between aerosol oxalic acid and zinc

    NASA Astrophysics Data System (ADS)

    Xing, L.; Fu, T.-M.; Cao, J. J.; Lee, S. C.; Wang, G. H.; Ho, K. F.; Cheng, M.-C.; You, C.-F.; Wang, T. J.

    2013-01-01

    We calculated the organic matter to organic carbon mass ratios (OM/OC mass ratios) in PM2.5 collected from 14 Chinese cities during summer and winter of 2003 and analyzed the causes for their seasonal and spatial variability. The OM/OC mass ratios were calculated two ways. Using a mass balance method, the calculated OM/OC mass ratios averaged 1.92 ± 0.39 yr-round, with no significant seasonal or spatial variation. The second calculation was based on chemical species analyses of the organic compounds extracted from the PM2.5 samples using dichloromethane/methanol and water. The calculated OM/OC mass ratio in summer was relatively high (1.75 ± 0.13) and spatially-invariant, due to vigorous photochemistry and secondary OA production throughout the country. The calculated OM/OC mass ratio in winter (1.59 ± 0.18) was significantly lower than that in summer, with lower values in northern cities (1.51 ± 0.07) than in southern cities (1.65 ± 0.15). This likely reflects the wider usage of coal for heating purposes in northern China in winter, in contrast to the larger contributions from biofuel and biomass burning in southern China in winter. On average, organic matters constituted 36% and 34% of Chinese urban PM2.5 mass in summer and winter, respectively. We reported, for the first time, high correlations between Zn and oxalic acid in Chinese urban aerosols in summer. This is consistent with the formation of stable Zn oxalate complex in the aerosol phase previously proposed by Furukawa and Takahashi (2011). We found that many other dicarboxylic acids were also highly correlated with Zn in the summer Chinese urban aerosol samples, suggesting that they may also form stable organic complexes with Zn. Such formation may have profound implications for the atmospheric abundance and hygroscopic property of aerosol dicarboxylic acids.

  13. On the Etiology of Molar-Incisor Hypomineralization.

    PubMed

    Vieira, Alexandre R; Kup, Elaine

    2016-01-01

    Molar-incisor hypomineralization (MIH) is a condition that is defined based on its peculiar clinical presentation. Reports on the etiology of the condition and possible risk factors are inconclusive and the original suggestion that MIH is an idiopathic condition is often cited. Our group was the first to suggest MIH has a genetic component that involves genetic variation in genes expressed during dental enamel formation. In this report, we provide a rationale to explain the preferential affection of molars and incisors. We suggest that MIH is a genetic condition based on its prevalence, which varies depending on the geographic location, and the evidence that on occasion second primary molars, permanent canines, and premolars can show signs of hypomineralization of enamel when molars and incisors are affected. PMID:27111773

  14. A Multidisciplinary Approach for Managing Severely Malaligned Lower Molars.

    PubMed

    Keinan, David; Birnboim-Blaum, Galit; Webber, Mariel

    2016-01-01

    An impacted mandibular molar is a common clinical situation that may damage adjacent teeth and impair periodontal health. Improper treatment brings the risk of damaging adjacent vital tissues. The risk can be reduced by early diagnosis and extraction of the impacted tooth by an experienced clinician. However, in clinical cases of two impacted molars, it may be beneficial for the patient to save at least one molar. This can be achieved by orthodontic alignment of one of the molars, while extracting the other. The decision should be based upon prognosis and risks for each procedure and for both teeth. The case presented here demonstrates a recommended clinical decision-making process before treatment, followed by monitored multidisciplinary treatment with adaptations made as the treatment progresses. PMID:26939154

  15. Reanalysis of the Lukeino molar (KNM-LU 335).

    PubMed

    Ungar, P S; Walker, A; Coffing, K

    1994-06-01

    This paper details a reanalysis of KNM-LU 335, a hominoid mandibular first molar dated to about 6 Ma from the Lukeino Formation, Kenya. Researchers have argued that this molar closely resembles those of modern chimpanzees and may approximate the ancestral morphotype of humans and chimpanzees. The investigation presented here describes a morphometric study of the Lukeino molar and M1s of Homo sapiens, Pan troglodytes, and early australopithecines. Results indicate that KNM-LU 335 differs from both human and chimpanzee M1s in relative distances (measured in three dimensions) between crown fissure termini. Further, the Lukeino molar shares with early australopithecines a pronounced flaring of the buccal surface of the crown not seen for either modern sample. Results of this study do not exclude KNM-LU 335 as a potential ancestral morphotype for Pan and Homo but provide no evidence that this morphotype resembled modern chimpanzees. PMID:8085609

  16. Treatment of a Maxillary First Molar with Two Palatal Roots

    PubMed Central

    Asghari, Vahideh; Rahimi, Saeed; Ghasemi, Negin; Talebzadeh, Bita; Norlouoni, Ahmad

    2015-01-01

    Thorough knowledge of the morphology and internal anatomy of the root canal system is essential, because it determines the successful outcome of endodontic treatment. The main goal of endodontic treatment is to prevent apical periodontitis and/or to promote the healing of periapical lesion. Presence of two canals or roots on the palatal side of the first maxillary molar has rarely been reported. This case report presents a maxillary first molar with two separate palatal roots. PMID:26523146

  17. Cervicothoracic Subcutaneous Emphysema and Pneumomediastinum After Third Molar Extraction.

    PubMed

    Picard, Maxime; Pham Dang, Nathalie; Mondie, Jean Michel; Barthelemy, Isabelle

    2015-12-01

    Third molar extraction is one of the most common interventions in dental and maxillofacial surgery. Complications are frequent and well documented, with swelling, pain, bleeding, infection, and lingual or alveolar nerve injury being the most common. This report describes a case of subcutaneous extensive emphysema and pneumomediastinum that occurred 4 days after extraction of an impacted right mandibular third molar. The management and etiology of this case and those reported in the literature are discussed. PMID:26341684

  18. Fusion or gemination? An unusual mandibular second molar

    PubMed Central

    Camargo, Angela Jordão; Arita, Emiko Saito; Watanabe, Plauto Christopher Aranha

    2015-01-01

    Fusion and gemination is not an uncommon finding and affected most primary dentition and the permanent maxillary incisors. These changes can develop a series of complication. A 11-year-old male presented radiography finding: an unusual mandibular second molar. A well-documented case brings a challenge for radiologists classify between fusion and gemination. In conclusion, this alteration although common in other regions, there are no case in the literature involving “second and third” molar. PMID:26945485

  19. The orthodontic extraction of permanent molars: a literature review.

    PubMed

    Chua, Emilia S L; Felicita, A Sumathi

    2015-05-01

    The most common cause of dental crowding is the presence of an arch-length--tooth-size discrepancy. Conventional methods of gaining space in orthodontics involve the extraction of teeth, often premolars. However, there are a number of clinical situations in which the extraction of permanent molars might be considered. This paper highlights the indications, advantages, disadvantages and timing of the extraction of the first, second and third permanent molars in the treatment of a crowded malocclusion. PMID:26219149

  20. Fusion or gemination? An unusual mandibular second molar.

    PubMed

    Camargo, Angela Jordão; Arita, Emiko Saito; Watanabe, Plauto Christopher Aranha

    2016-01-01

    Fusion and gemination is not an uncommon finding and affected most primary dentition and the permanent maxillary incisors. These changes can develop a series of complication. A 11-year-old male presented radiography finding: an unusual mandibular second molar. A well-documented case brings a challenge for radiologists classify between fusion and gemination. In conclusion, this alteration although common in other regions, there are no case in the literature involving "second and third" molar. PMID:26945485

  1. Optical high acidity sensor

    DOEpatents

    Jorgensen, B.S.; Nekimken, H.L.; Carey, W.P.; O`Rourke, P.E.

    1997-07-22

    An apparatus and method for determining acid concentrations in solutions having acid concentrations of from about 0.1 Molar to about 16 Molar is disclosed. The apparatus includes a chamber for interrogation of the sample solution, a fiber optic light source for passing light transversely through the chamber, a fiber optic collector for receiving the collimated light after transmission through the chamber, a coating of an acid resistant polymeric composition upon at least one fiber end or lens, the polymeric composition in contact with the sample solution within the chamber and having a detectable response to acid concentrations within the range of from about 0.1 Molar to about 16 Molar, a measurer for the response of the polymeric composition in contact with the sample solution, and a comparer of the measured response to predetermined standards whereby the acid molarity of the sample solution within the chamber can be determined. Preferably, a first lens is attached to the end of the fiber optic light source, the first lens adapted to collimate light from the fiber optic light source, and a second lens is attached to the end of the fiber optic collector for focusing the collimated light after transmission through the chamber. 10 figs.

  2. Optical high acidity sensor

    DOEpatents

    Jorgensen, Betty S.; Nekimken, Howard L.; Carey, W. Patrick; O'Rourke, Patrick E.

    1997-01-01

    An apparatus and method for determining acid concentrations in solutions having acid concentrations of from about 0.1 Molar to about 16 Molar is disclosed. The apparatus includes a chamber for interrogation of the sample solution, a fiber optic light source for passing light transversely through the chamber, a fiber optic collector for receiving the collimated light after transmission through the chamber, a coating of an acid resistant polymeric composition upon at least one fiber end or lens, the polymeric composition in contact with the sample solution within the chamber and having a detectable response to acid concentrations within the range of from about 0.1 Molar to about 16 Molar, a measurer for the response of the polymeric composition in contact with the sample solution, and, a comparer of the measured response to predetermined standards whereby the acid molarity of the sample solution within the chamber can be determined. Preferably, a first lens is attached to the end of the fiber optic light source, the first lens adapted to collimate light from the fiber optic light source, and a second lens is attached to the end of the fiber optic collector for focusing the collimated light after transmission through the chamber.

  3. Root canal morphology of South Asian Indian maxillary molar teeth

    PubMed Central

    Singh, Shishir; Pawar, Mansing

    2015-01-01

    Objective: The objective was to study the root canal morphology of South Asian Indian Maxillary molars using a tooth clearing technique. Materials and Methods: Hundred teeth each comprising of first, second, and third molars collected from different dental schools and clinics in India were subjected to standard dye penetration, decalcification and clearing procedure before being studied. Results: The first molar mesiobuccal roots exhibited 69% Type I, 24% Type II, 4% Type IV, 2% Type V, and 1% exhibited a Vertuccis Type VIII canal anatomy. In the group with three separate roots the second molar mesiobuccal roots in exhibited 80.6% Type I, 15.3% Type II, 2.7% Type IV, and 1.4% Type V canal anatomy while the third molars mesiobuccal roots exhibited 57.4% Type I, 32% Type II, 2.1% Type III, 8.5% Type IV, 1% had a Type V canal anatomy in the similar group. Conclusion: A varied root canal anatomy was seen in the mesiobuccal root canal of the maxillary molars. PMID:25713497

  4. Kissing molars extraction: Case series and review of the literature

    PubMed Central

    Arjona-Amo, Manuel; Torres-Carranza, Eusebio; Batista-Cruzado, Antonio; Serrera-Figallo, Maria-Angeles; Crespo-Torres, Santos; Belmonte-Caro, Rodolfo; Albisu-Andrade, Claudio; Gutiérrez-Pérez, José-Luis

    2016-01-01

    Kissing molars are a very rare form of inclusion defined as molars included in the same quadrant, with occlusal surfaces contacting each other within a single dental follicle. We present four cases of this pathology: a 35 year-old male, referred to the Oral and Maxillofacial Surgery Department of the Hospital Virgen del Rocio in Seville, and three females of 24, 26, and 31 years, all of which had kissing molars that were treated by tooth extraction. We have found only 10 cases published in the medical literature in which this type of inclusion is briefly described, none of which elaborate on the surgical technique employed. In these cases, the indication for surgery is established when there is a history of recurring infections or cystic lesions associated with dental inclusions. The extraction of kissing molars requires an exhaustive comprehension of the anatomy of the region involved, sufficiently developed surgical abilities, and an extensive planning process. Key words:Impacted molar, kissing molar, surgical extraction. PMID:26855716

  5. Finite Element Reconstruction of a Mandibular First Molar

    PubMed Central

    Ehsani, Sara; Mirhashemi, Fatemeh Sadat; Asgary, Saeed

    2013-01-01

    Introduction Mandibular first molar is the most important tooth with complicated morphology. In finite element (FE) studies, investigators usually prefer to model anterior teeth with a simple and single straight root; it makes the results deviate from the actual case. The most complicated and time-consuming step in FE studies is modeling of the desired tooth, thus this study was performed to establish a finite element method (FEM) of reconstructing a mandibular first molar with the greatest precision. Materials and Methods An extracted mandibular first molar was digitized, and then radiographed from different aspects to achieve its outer and inner morphology. The solid model of tooth and root canals were constructed according to this data as well as the anatomy of mandibular first molar described in the literature. Result A three-dimensional model of mandibular first molar was created, giving special consideration to shape and root canal system dimensions. Conclusion This model may constitute a basis for investigating the effect of different clinical situations on mandibular first molars in vitro, especially on its root canal system. The method described here seems feasible and reasonably precise foundation for investigations. PMID:23717327

  6. Monitoring potential molecular interactions of adenine with other amino acids using Raman spectroscopy and DFT modeling.

    PubMed

    Singh, Shweta; Donfack, P; Srivastava, Sunil K; Singh, Dheeraj K; Materny, A; Asthana, B P; Mishra, P C

    2015-10-01

    We report on the modes of inter-molecular interaction between adenine (Ade) and the amino acids: glycine (Gly), lysine (Lys) and arginine (Arg) using Raman spectroscopy of binary mixtures of adenine and each of the three amino acids at varying molar ratios in the spectral region 1550-550 cm(-1). We focused our attention on certain specific changes in the Raman bands of adenine arising due to its interaction with the amino acids. While the changes are less apparent in the Ade/Gly system, in the Ade/Lys or Ade/Arg systems, significant changes are observed, particularly in the Ade Raman bands that involve the amino group moiety and the N7 and N1 atoms of the purine ring. The ν(N1-C6), ν(N1-C2), δ(C8-H) and δ(N7-C8-N9) vibrations at 1486, 1332, 1253 and 948 cm(-1) show spectral changes on varying the Ade to amino acid molar ratio, the extent of variation being different for the three amino acids. This observation suggests a specific interaction mode between Ade and Lys or Arg, which is due to the hydrogen bonding. The measured spectral changes provide a clear indication that the interaction of Ade depends strongly on the structures of the amino acids, especially their side chains. Density functional theory (DFT) calculations were carried out to elucidate the most probable interaction modes of Ade with the different amino acids. PMID:25985129

  7. Using acid insoluble ash marker ratios (diet:digesta) to predict digestibility of wheat and barley metabolizable energy and nitrogen retention in broiler chicks.

    PubMed

    Scott, T A; Hall, J W

    1998-05-01

    Routine bioassay measurements of AME or N retention of broiler diets require measurements of gross energy (GE) or N and an acid insoluble ash marker in diet, excreta, or ileal digesta. These measurements of GE and N are time-consuming and expensive in comparison to measurements of added or natural occurring levels of acid insoluble ash. Data from bioassay measurements of AME and N retention of 138 wheat and 97 barley samples (with or without enzyme) were used to develop prediction equations relying on measurements of one that uses acid insoluble ash of diet, excreta or ileal digesta and GE and N of diet only; and a second equation using only acid insoluble ash of diet, excreta, or ileal digesta. The prediction equations demonstrate that part of or all of routine bomb calorimetry measurements for GE used to determine AME of wheat- or barley-based diets could be eliminated if a prediction error of 80 kcal/kg ME or less were acceptable. The prediction of N retention as compared to AME, based in part or totally on acid insoluble ash measurements, was less accurate; the prediction errors were equal to 2.3 and 6.5% for wheat- and barley-based diets, respectively. Ongoing research to improve the determination (speed, ease, and accuracy) of acid insoluble ash could provide a useful method to assess feeding value of ingredients and commercial poultry diets. PMID:9603354

  8. Reaction kinetics of free fatty acids esterification in palm fatty acid distillate using coconut shell biochar sulfonated catalyst

    NASA Astrophysics Data System (ADS)

    Hidayat, Arif; Rochmadi, Wijaya, Karna; Budiman, Arief

    2015-12-01

    Recently, a new strategy of preparing novel carbon-based solid acids has been developed. In this research, the esterification reactions of Palm Fatty Acid Distillate (PFAD) with methanol, using coconut shell biochar sulfonated catalyst from biomass wastes as catalyst, were studied. In this study, the coconut shell biochar sulfonated catalysts were synthesized by sulfonating the coconut shell biochar using concentrated H2SO4. The kinetics of free fatty acid (FFA) esterification in PFAD using a coconut shell biochar sulfonated catalyst was also studied. The effects of the mass ratio of catalyst to oil (1-10%), the molar ratio of methanol to oil (6:1-12:1), and the reaction temperature (40-60°C) were studied for the conversion of PFAD to optimize the reaction conditions. The results showed that the optimal conditions were an methanol to PFAD molar ratio of 12:1, the amount of catalyst of 10%w, and reaction temperature of 60°C. The proposed kinetic model shows a reversible second order reaction and represents all the experimental data satisfactorily, providing deeper insight into the kinetics of the reaction.

  9. Stepwise esterification of phytosterols with conjugated linoleic acid catalyzed by Candida rugosa lipase in solvent-free medium.

    PubMed

    Torres, Carlos F; Torrelo, Guzman; Vazquez, Luis; Señorans, F Javier; Reglero, Guillermo

    2008-12-01

    We conducted a near quantitative esterification of phytosterols from soybean oil deodorizer distillate with conjugated linoleic acid. We used a 1:1 molar ratio of sterols to conjugated linoleic acid. For that matter, stepwise addition of sterols was investigated. Total sterols were divided into several portions and added sequentially to the reaction mixture. Using this methodology, purities of up to 80% steryl esters were obtained that consumed more than 90% of the total conjugated linoleic acid. In addition, the effects of temperature, amount, and stability of lipase were also evaluated. PMID:19134551

  10. Standardised studies on Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM): a need.

    PubMed

    Elfrink, M E C; Ghanim, A; Manton, D J; Weerheijm, K L

    2015-06-01

    In November 2014, a review of literature concerning prevalence data of Molar Incisor Hypomineralisation (MIH) and Hypomineralised Second Primary Molars (HSPM) was performed. A search of PubMed online databases was conducted for relevant articles published until November 2014. The reference lists of all retrieved articles were hand-searched. Studies were included after assessing the eligibility of the full-text article. Out of 1078 manuscripts, a total of 157 English written publications were selected based on title and abstract. Of these 157, 60 were included in the study and allocated as 52 MIH and 5 HSPM, and 3 for both MIH and HSPM. These studies utilised the European Academy of Paediatric Dentistry judgment criteria, the modified index of developmental defects of enamel (mDDE) and self-devised criteria, and demonstrated a wide variation in the reported prevalence (MIH 2.9-44 %; HSPM 0-21.8 %). Most values mentioned were representative for specific areas. More studies were performed in cities compared with rural areas. A great variation was found in calibration methods, number of participants, number of examiners and research protocols between the studies. The majority of the prevalence studies also investigated possible aetiological factors. To compare MIH and HSPM prevalence and or aetiological data around the world, standardisation of such studies seems essential. Standardisation of the research protocol should include a clearly described sample of children (minimum number of 300 for prevalence and 1000 for aetiology studies) and use of the same calibration sets and methods whereas aetiological studies need to be prospective in nature. A standardised protocol for future MIH and HSPM prevalence and aetiology studies is recommended. PMID:25894247

  11. Fidelity of leaf-wax n-alkane and n-alkanoic acid D/H ratios in space and time

    NASA Astrophysics Data System (ADS)

    Polissar, P. J.; Preefer, M. B.; Liu, C.

    2014-12-01

    There is great potential for reconstructing past changes in the hydrologic cycle using the hydrogen isotopic composition of plant-wax biomarkers. However, empirical relationships relating plant-wax hydrogen isotope compositions (δDwax) to source water are almost exclusively based upon modern plants, soils and sediments and a single compound class such as n-alkanes or n-alkanoic acids. Relatively little is known about the relationship between these compound classes and differences in how they record the hydrogen isotopic composition of source water. Here we present new hydrogen isotopic measurements from a suite of modern and late Quaternary lake sediment samples to test the fidelity of δDwaxto source water δD in space and time. We find that within compound class the shared variance between C29 and C31 n-alkane and C28 and C30 n-alkanoic acid δD values is 87% and 86%. Between compound classes there is 53% shared variance between C29 n-alkane and C28 n-acid δD values. The apparent isotopic fractionation between source water and n-alkane δD values is consistent with prior studies from these regions that show the influence of vegetation type and climate. However, the n-alkanoic acid apparent fractionation values cannot be explained by these factors alone. Rather, the data require that for a large proportion of the samples there is a substantial contribution of long-chain n-acids from vegetation that uses lake water as the hydrogen source for lipid synthesis. This is consistent with overlapping n-acid compound distributions in lake sediment, soils, and aquatic and terrestrial plants from many of these regions. Our results emphasize the utility of plant-wax δD for reconstructing water δD values and highlight the potential importance of non-terrestrial sources of long-chain n-acids in lake systems.

  12. Estimation of the standardized ileal digestible valine to lysine ratio required for 25- to 120-kilogram pigs fed low crude protein diets supplemented with crystalline amino acids.

    PubMed

    Liu, X T; Ma, W F; Zeng, X F; Xie, C Y; Thacker, P A; Htoo, J K; Qiao, S Y

    2015-10-01

    Four 28-d experiments were conducted to determine the standardized ileal digestible (SID) valine (Val) to lysine (Lys) ratio required for 26- to 46- (Exp. 1), 49- to 70- (Exp. 2), 71- to 92- (Exp. 3), and 94- to 119-kg (Exp. 4) pigs fed low CP diets supplemented with crystalline AA. The first 3 experiments utilized 150 pigs (Duroc × Landrace × Large White), while Exp. 4 utilized 90 finishing pigs. Pigs in all 4 experiments were randomly allocated to 1 of 5 diets with 6 pens per treatment (3 pens of barrows and 3 pens of gilts) and 5 pigs per pen for the first 3 experiments and 3 pigs per pen for Exp. 4. Diets for all experiments were formulated to contain SID Val to Lys ratios of 0.55, 0.60, 0.65, 0.70, or 0.75. In Exp. 1 (26 to 46 kg), ADG increased (linear, = 0.039; quadratic, = 0.042) with an increasing dietary Val:Lys ratio. The SID Val:Lys ratio to maximize ADG was 0.62 using a linear broken-line model and 0.71 using a quadratic model. In Exp. 2 (49 to 70 kg), ADG increased (linear, = 0.021; quadratic, = 0.042) as the SID Val:Lys ratio increased. G:F improved (linear, = 0.039) and serum urea nitrogen (SUN) decreased (linear, = 0.021; quadratic, = 0.024) with an increased SID Val:Lys ratio. The SID Val:Lys ratios to maximize ADG as well as to minimize SUN levels were 0.67 and 0.65, respectively, using a linear broken-line model and 0.72 and 0.71, respectively, using a quadratic model. In Exp. 3 (71 to 92 kg), ADG increased (linear, = 0.007; quadratic, = 0.022) and SUN decreased (linear, = 0.011; quadratic, = 0.034) as the dietary SID Val:Lys ratio increased. The SID Val:Lys ratios to maximize ADG as well as to minimize SUN levels were 0.67 and 0.67, respectively, using a linear broken-line model and 0.72 and 0.74, respectively, using a quadratic model. In Exp. 4 (94 to 119 kg), ADG increased (linear, = 0.041) and G:F was improved (linear, = 0.004; quadratic, = 0.005) as the dietary SID Val:Lys ratio increased. The SID Val:Lys ratio to maximize G:F was 0

  13. Synthesis and characterization of self-assembled polyaniline nanotubes doped with D-10-camphorsulfonic acid

    NASA Astrophysics Data System (ADS)

    Zhang, Lijuan; Wan, Meixiang

    2002-12-01

    Conducting nanotubes of polyaniline (PANI) about 80-180 nm in diameter were synthesized by a chemical template-free method in the presence of D-10-camphorsulfonic acid (D-CSA) as the dopant, and ammonium persulfate ((NH4)2S2O8) as the oxidant. The effect of synthetic conditions, such as the molar ratio of D-CSA to aniline (An), the concentration of D-CSA in the polymerization media, the reaction temperature and time, on the morphology and size as well as the electrical properties of the PANI-(D-CSA) was investigated. It was found that the above synthetic conditions, especially the molar ratio of D-CSA to An, strongly affected the morphology and formation probability of the resulting PANI. The micelles formed by D-CSA and anilinium cations act as the templates in the formation of PANI-(D-CSA) nanotubes.

  14. Genetic integration of molar cusp size variation in baboons.

    PubMed

    Koh, Christina; Bates, Elizabeth; Broughton, Elizabeth; Do, Nicholas T; Fletcher, Zachary; Mahaney, Michael C; Hlusko, Leslea J

    2010-06-01

    Many studies of primate diversity and evolution rely on dental morphology for insight into diet, behavior, and phylogenetic relationships. Consequently, variation in molar cusp size has increasingly become a phenotype of interest. In 2007 we published a quantitative genetic analysis of mandibular molar cusp size variation in baboons. Those results provided more questions than answers, as the pattern of genetic integration did not fit predictions from odontogenesis. To follow up, we expanded our study to include data from the maxillary molar cusps. Here we report on these later analyses, as well as inter-arch comparisons with the mandibular data. We analyzed variation in two-dimensional maxillary molar cusp size using data collected from a captive pedigreed breeding colony of baboons, Papio hamadryas, housed at the Southwest National Primate Research Center. These analyses show that variation in maxillary molar cusp size is heritable and sexually dimorphic. We also estimated additive genetic correlations between cusps on the same crown, homologous cusps along the tooth row, and maxillary and mandibular cusps. The pattern for maxillary molars yields genetic correlations of one between the paracone-metacone and protocone-hypocone. Bivariate analyses of cuspal homologues on adjacent teeth yield correlations that are high or not significantly different from one. Between dental arcades, the nonoccluding cusps consistently yield high genetic correlations, especially the metaconid-paracone and metaconid-metacone. This pattern of genetic correlation does not immediately accord with the pattern of development and/or calcification, however these results do follow predictions that can be made from the evolutionary history of the tribosphenic molar. PMID:20034010

  15. Erupted complex odontoma delayed eruption of permanent molar.

    PubMed

    Ohtawa, Yumi; Ichinohe, Saori; Kimura, Eri; Hashimoto, Sadamitsu

    2013-01-01

    Odontomas, benign tumors that develop in the jaw, rarely erupt into the oral cavity. We report an erupted odontoma which delayed eruption of the first molar. The patient was a 10-year-old Japanese girl who came to our hospital due to delayed eruption of the right maxillary first molar. All the deciduous teeth had been shed. The second premolar on the right side had erupted, but not the first molar. Slight inflammation of the alveolar mucosa around the first molar had exposed a tooth-like, hard tissue. Panoramic radiography revealed a radiopaque mass indicating a lesion approximately 1 cm in diameter. The border of the image was clear, and part of the mass was situated close to the occlusal surface of the first molar. The root of the maxillary right first molar was only half-developed. A clinical diagnosis of odontoma was made. The odontoma was subsequently extracted, allowing the crown of the first molar to erupt almost 5 months later. The dental germ of the permanent tooth had been displaced by the odontoma. However, after the odontoma had been extracted, the permanent tooth was still able to erupt spontaneously, as eruptive force still remained. When the eruption of a tooth is significantly delayed, we believe that it is necessary to examine the area radiographically. If there is any radiographic evidence of a physical obstruction that might delay eruption, that obstruction should be removed before any problems can arise. Regular dental checkups at schools might improve our ability to detect evidence of delayed eruption earlier. PMID:24521551

  16. Molar Intrusion in Open-bite Adults Using Zygomatic Miniplates.

    PubMed

    Marzouk, Eiman S; Abdallah, Essam Mohamed; El-Kenany, Walid A

    2015-01-01

    The aim of this study is to evaluate the skeletal, dental and soft tissue changes that arise after intrusion of the maxillary molars using zygomatic miniplates in adult skeletal anterior open bite patients. In addition to measuring the amount and rate of molar intrusion; with special emphasis on changes in the axial inclination of the intruded molars. The study group was composed of 13 anterior open bite patients (mean age 18 years, 8 months ± 2 years, 2 months) with posterior dentoalveolar excess. Mini-plates were placed in the zygomatic buttress bilaterally. The upper arch was segmentally leveled and a double Trans-Palatal Arch (TPA) was bonded. Closed NiTi coil spring was placed bilaterally between the book of the mini-plate just mesial and distal to the first molar buccal tube applying intrusive force of 450 gper side. Lateral and posteroanterior cephalograms were taken before intrusion (T1: post upper segmental leveling) and after intrusion (T2). Comparison between means before and after the intrusion was done using Wilcoxon Signed Ranks test (WSRT). Mandibular autorotation followed the molar intrusion, SNB and SN-Pog angles significantly increased while the ANB, MP-SN angle and N-S-Gn angle significantly decreased. The mean amount of accomplished molar intrusion was 3.1mm ± 0.74mm, with a rate of 0.36mm per month ± 0.08mm per month and a bite closure of 6.55mm ± 1.83mm. There was no significant buccal tip in the right and left molars upon intrusion. Conclusion: Miniplates zygomatic anchorage can be used effectively for skeletal open bite correction through posterior dento-alveolar intrusion. Intrusion of the posterior teeth with skeletal anchorage induced counterclockwise rotation of the mandible and, as a consequence, corrected the anteroposterior intermaxillary relationship with a dramatic improvement in the facial soft tissue convexity. PMID:26349291

  17. Genetic integration of molar cusp size variation in baboons

    PubMed Central

    Koh, Christina; Bates, Elizabeth; Broughton, Elizabeth; Do, Nicholas T.; Fletcher, Zachary; Mahaney, Michael C.; Hlusko, Leslea J.

    2010-01-01

    Many studies of primate diversity and evolution rely on dental morphology for insight into diet, behavior, and phylogenetic relationships. Consequently, variation in molar cusp size has increasingly become a phenotype of interest. In 2007 we published a quantitative genetic analysis of mandibular molar cusp size variation in baboons. Those results provided more questions than answers, as the pattern of genetic integration did not fit predictions from odontogenesis. To follow up, we expanded our study to include data from the maxillary molar cusps. Here we report on these later analyses, as well as inter-arch comparisons with the mandibular data. We analyzed variation in two-dimensional maxillary molar cusp size using data collected from a captive pedigreed breeding colony of baboons, Papio hamadryas, housed at the Southwest National Primate Research Center. These analyses show that variation in maxillary molar cusp size is heritable and sexually dimorphic. We also estimated additive genetic correlations between cusps on the same crown, homologous cusps along the tooth row, and maxillary and mandibular cusps. The pattern for maxillary molars yields genetic correlations of one between the paracone-metacone and protocone-hypocone. Bivariate analyses of cuspal homologues on adjacent teeth yield correlations that are high or not significantly different from one. Between dental arcades, the non-occluding cusps consistently yield high genetic correlations, especially the metaconid-paracone and metaconid-metacone. This pattern of genetic correlation does not immediately accord with the pattern of development and/or calcification, however these results do follow predictions that can be made from the evolutionary history of the tribosphenic molar. PMID:20034010

  18. First molar health status in different craniofacial relationships

    PubMed Central

    Linjawi, Amal I

    2016-01-01

    Objective To investigate the association between the health status of permanent first molars and different craniofacial relationships among adolescents. Study design This is a retrospective study on patients’ records aged 11–15 years. Sex, skeletal relationship, vertical growth pattern, malocclusion, overjet, and overbite were assessed. The health status of permanent first molars was recorded from the orthopantomograms and intraoral photographs as “sound” and “not sound”. Chi-square, Mann–Whitney U and Kruskal–Wallis tests, and Pearson’s correlation coefficient were used to analyze and correlate the assessed variables. Significance level was set at P<0.05. Results A total of 210 records were evaluated; 81 were male, 68 had Class I and 91 had Class II skeletal relationships. More than half of the subjects had normal (n=67) to moderate deep bite (n=72); normal (n=91), moderately increased (n=54), to severely increased (n=50) overjet; and Class I (n=106) and Class II division 1 (n=75) malocclusion. Significant differences were found in the health status of the permanent first molars with respect to sex (P=0.034), vertical growth pattern (P=0.01), and overbite (P=0.047). Strong correlations were only found between the health status of the permanent first molars and the following variables: sex (P=0.036) and vertical growth pattern (P=0.004). Significant correlation was further found between the upper left first molar health status and sex (P=0.019) and the lower right first molar health status and the vertical growth pattern (P=0.001). No significant association was found with the anteroposterior craniofacial relationships (P>0.05). Conclusion Sex difference and vertical growth patterns were found to be potential predictors of the health status of the permanent first molars. No significant association was found with the anteroposterior craniofacial relationships. PMID:27462176

  19. A conjugated fatty acid present at high levels in bitter melon seed favorably affects lipid metabolism in hepatocytes by increasing NAD(+)/NADH ratio and activating PPARα, AMPK and SIRT1 signaling pathway.

    PubMed

    Chen, Gou-Chun; Su, Hui-Min; Lin, Yu-Shun; Tsou, Po-Yen; Chyuan, Jong-Ho; Chao, Pei-Min

    2016-07-01

    α-Eleostearic acid (α-ESA), or the cis-9, trans-11, trans-13 isomer of conjugated linolenic acid, is a special fatty acid present at high levels in bitter melon seed oil. The aim of this study was to examine the effect of α-ESA on hepatic lipid metabolism. Using H4IIEC3 hepatoma cell line, we showed that α-ESA significantly lowered intracellular triglyceride accumulation compared to α-linolenic acid (LN), used as a fatty acid control, in a dose- and time-dependent manner. The effects of α-ESA on enzyme activities and mRNA profiles in H4IIEC3 cells suggested that enhanced fatty acid oxidation and lowered lipogenesis were involved in α-ESA-mediated triglyceride lowering effects. In addition, α-ESA triggered AMP-activated protein kinase (AMPK) activation without altering sirtuin 1 (SIRT1) protein levels. When cells were treated with vehicle control (VC), LN alone (LN; 100μmol/L) or in combination with α-ESA (LN+α-ESA; 75+25μmol/L) for 24h, acetylation of forkhead box protein O1 was decreased, while the NAD(+)/NADH ratio, mRNA levels of NAMPT and PTGR1 and enzyme activity of nicotinamide phosphoribosyltransferase were increased by LN+α-ESA treatment compared to treatment with LN alone, suggesting that α-ESA activates SIRT1 by increasing NAD(+) synthesis and NAD(P)H consumption. The antisteatosis effect of α-ESA was confirmed in mice treated with a high-sucrose diet supplemented with 1% α-ESA for 5weeks. We conclude that α-ESA favorably affects hepatic lipid metabolism by increasing cellular NAD(+)/NADH ratio and activating PPARα, AMPK and SIRT1 signaling pathways. PMID:27260465

  20. The Ratio of Dietary Branched-Chain Amino Acids is Associated with a Lower Prevalence of Obesity in Young Northern Chinese Adults: An Internet-Based Cross-Sectional Study.

    PubMed

    Li, Yan-Chuan; Li, Ying; Liu, Li-Yan; Chen, Yang; Zi, Tian-Qi; Du, Shan-Shan; Jiang, Yong-Shuai; Feng, Ren-Nan; Sun, Chang-Hao

    2015-11-01

    This study aims to examine the association between the ratio of dietary branched chain amino acids (BCAA) and risk of obesity among young northern Chinese adults. A total of 948 randomly recruited participants were asked to finish our internet-based dietary questionnaire for the Chinese (IDQC). Associations between dietary BCAA ratio and prevalence of overweight/obesity and abdominal obesity were analyzed. Furthermore, 90 subjects were randomly selected to explore the possible mechanism. Dietary BCAA ratio in obese participants was significantly lower than non-obese participants. We found negative correlations between the ratio of dietary BCAA and body mass index (BMI) (r = -0.197, p < 0.001) or waist circumference (r = -0.187, p < 0.001). Compared with those in the first quartile, the multivariable-adjusted OR (95% CI) of the 3rd and 4th quartiles of dietary BCAA ratio for overweight/obesity were 0.508 (0.265-0.972) and 0.389 (0.193-0.783), respectively (all p < 0.05). After stratification by gender, the significance still existed in the 3rd and 4th quartile in males and the 4th quartile in females. For abdominal obesity, the multivariable-adjusted OR (95% CI) of the 3rd and 4th quartile of dietary BCAA ratio were 0.351 (0.145-0.845) and 0.376 (0.161-0.876), respectively (all p < 0.05). This significance was stronger in males. Further studies indicated that dietary BCAA ratio was inversely associated with 2-h postprandial glucose (2 h-PG) and status of inflammation. In conclusion, a higher ratio of dietary BCAA is inversely associated with prevalence of obesity, postprandial glucose and status of inflammation in young northern Chinese adults. PMID:26593945

  1. The Ratio of Dietary Branched-Chain Amino Acids is Associated with a Lower Prevalence of Obesity in Young Northern Chinese Adults: An Internet-Based Cross-Sectional Study

    PubMed Central

    Li, Yan-Chuan; Li, Ying; Liu, Li-Yan; Chen, Yang; Zi, Tian-Qi; Du, Shan-Shan; Jiang, Yong-Shuai; Feng, Ren-Nan; Sun, Chang-Hao

    2015-01-01

    This study aims to examine the association between the ratio of dietary branched chain amino acids (BCAA) and risk of obesity among young northern Chinese adults. A total of 948 randomly recruited participants were asked to finish our internet-based dietary questionnaire for the Chinese (IDQC). Associations between dietary BCAA ratio and prevalence of overweight/obesity and abdominal obesity were analyzed. Furthermore, 90 subjects were randomly selected to explore the possible mechanism. Dietary BCAA ratio in obese participants was significantly lower than non-obese participants. We found negative correlations between the ratio of dietary BCAA and body mass index (BMI) (r = −0.197, p < 0.001) or waist circumference (r = −0.187, p < 0.001). Compared with those in the first quartile, the multivariable-adjusted OR (95% CI) of the 3rd and 4th quartiles of dietary BCAA ratio for overweight/obesity were 0.508 (0.265–0.972) and 0.389 (0.193–0.783), respectively (all p < 0.05). After stratification by gender, the significance still existed in the 3rd and 4th quartile in males and the 4th quartile in females. For abdominal obesity, the multivariable-adjusted OR (95% CI) of the 3rd and 4th quartile of dietary BCAA ratio were 0.351 (0.145–0.845) and 0.376 (0.161–0.876), respectively (all p < 0.05). This significance was stronger in males. Further studies indicated that dietary BCAA ratio was inversely associated with 2-h postprandial glucose (2 h-PG) and status of inflammation. In conclusion, a higher ratio of dietary BCAA is inversely associated with prevalence of obesity, postprandial glucose and status of inflammation in young northern Chinese adults. PMID:26593945

  2. The ratio of oleic-to-stearic acid in the prostate predicts biochemical failure after radical prostatectomy for localized prostate cancer

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Our study examined lifestyle-related factors that may influence the prognosis of clinically localized prostate cancer, we evaluated the relative impact of obesity and prostatic fatty acid concentrations at diagnosis on risk of biochemical failure following radical prostatectomy. Height and weight w...

  3. Synthesis of Rosin Acid Starch Catalyzed by Lipase

    PubMed Central

    Lin, Rihui; Li, He; Long, Han; Su, Jiating; Huang, Wenqin

    2014-01-01

    Rosin, an abundant raw material from pine trees, was used as a starting material directly for the synthesis of rosin acid starch. The esterification reaction was catalyzed by lipase (Novozym 435) under mild conditions. Based on single factor experimentation, the optimal esterification conditions were obtained as follows: rosin acid/anhydrous glucose unit in the molar ratio 2 : 1, reaction time 4 h at 45°C, and 15% of lipase dosage. The degree of substitution (DS) reaches 0.098. Product from esterification of cassava starch with rosin acid was confirmed by FTIR spectroscopy and iodine coloration analysis. Scanning electron microscopy and X-ray diffraction analysis showed that the morphology and crystallinity of the cassava starch were largely destroyed. Thermogravimetric analysis indicated that thermal stability of rosin acid starch decreased compared with native starch. PMID:24977156

  4. Preparation and Characterization of Sulfonic Acid Functionalized Silica and Its Application for the Esterification of Ethanol and Maleic Acid

    NASA Astrophysics Data System (ADS)

    Sirsam, Rajkumar; Usmani, Ghayas

    2016-04-01

    The surface of commercially available silica gel, 60-200 mesh size, was modified with sulfonic acid through surface activation, grafting of 3-Mercaptopropyltrimethoxysilane, oxidation and acidification of 3-Mercaptopropylsilica. Sulfonic Acid Functionalization of Silica (SAFS) was confirmed by Fourier Transform Infra-red (FTIR) spectroscopy and thermal gravimetric analysis. Acid-base titration was used to estimate the cation exchange capacity of the SAFS. Catalytic activity of SAFS was judged for the esterification of ethanol with maleic acid. An effect of different process parameters viz. molar ratio, catalyst loading, speed of agitation and temperature were studied and optimized by Box Behnken Design (BBD) of Response Surface Methodology (RSM). Quadratic model developed by BBD-RSM reasonably satisfied an experimental and predicted values with correlation coefficient value R2 = 0.9504.

  5. Requirement of alveolar bone formation for eruption of rat molars.

    PubMed

    Wise, Gary E; He, Hongzhi; Gutierrez, Dina L; Ring, Sherry; Yao, Shaomian

    2011-10-01

    Tooth eruption is a localized event that requires a dental follicle (DF) to regulate the resorption of alveolar bone to form an eruption pathway. During the intra-osseous phase of eruption, the tooth moves through this pathway. The mechanism or motive force that propels the tooth through this pathway is controversial but many studies have shown that alveolar bone growth at the base of the crypt occurs during eruption. To determine if this bone growth (osteogenesis) was causal, experiments were designed in which the expression of an osteogenic gene in the DF, bone morphogenetic protein-6 (Bmp6), was inhibited by injection of the first mandibular molar of the rat with a small interfering RNA (siRNA) targeted against Bmp6. The injection was followed by electroporation to promote uptake of the siRNA. In 45 first molars injected, eruption was either delayed or completely inhibited (seven molars). In the impacted molars, an eruption pathway formed but bone growth at the base of the crypt was greatly reduced compared with the erupted first-molar controls. These studies show that alveolar bone growth at the base of the crypt is required for tooth eruption and that Bmp6 may be essential for promoting this growth. PMID:21896048

  6. Requirement of alveolar bone formation for eruption of rat molars

    PubMed Central

    Wise, Gary E.; He, Hongzhi; Gutierrez, Dina L.; Ring, Sherry; Yao, Shaomian

    2011-01-01

    Tooth eruption is a localized event that requires a dental follicle (DF) to regulate the resorption of alveolar bone to form an eruption pathway. During the intra-osseous phase of eruption, the tooth moves through this pathway. The mechanism or motive force that propels the tooth through this pathway is controversial but many studies have shown that alveolar bone growth at the base of the crypt occurs during eruption. To determine if this bone growth (osteogenesis) was causal, experiments were designed in which the expression of an osteogenic gene in the DF, bone morphogenetic protein-6 (BMP6), was inhibited by injection of the 1st mandibular molar of the rat with an siRNA targeted against BMP6. The injection was followed by electroporation to promote uptake of the siRNA. In 45 first molars injected, eruption either was delayed or completely inhibited (7 molars). In the impacted molars, an eruption pathway formed but bone growth at the base of the crypt was greatly reduced as compared to the erupted first molar controls. These studies show that alveolar bone growth at the base of the crypt is required for tooth eruption and that BMP6 may be an essential gene for promoting this growth. PMID:21896048

  7. Orthodontic band retention on primary molar stainless steel crowns.

    PubMed

    Beemer, R L; Ferracane, J L; Howard, H E

    1993-01-01

    The retention of orthodontic bands cemented on primary molar stainless steel crowns (SSC) was studied in vitro. Unitek maxillary and mandibular 1st and 2nd primary molar SSC were fitted with one of four commonly used orthodontic bands (Unitek regular, Unitek narrow, Rocky Mountain, or custom bands made from SSC) using glass ionomer cement. The cemented samples were tested for their resistance to dislodgment on the Instron Universal Testing Machine (Instron Engineering Corp., Canton, MA) in tensile mode. Alpha level for statistical significance was set at alpha = 0.05. Unitek regular bands cemented on the 2nd molar crowns and Unitek narrow bands cemented on the 1st molar crown samples had equivalent or superior resistance to dislodgment compared with the other bands in the study. When the inside of the band and the outside band-bearing surfaces of selected crowns were lightly scored with a diamond bur prior to cementation, samples exhibited significantly superior retention. Subgroup means increased from 107 to 330%, compared to the values obtained in their preroughened state. The mean values obtained using the roughened band/crown interface technique (range 52.9 +/- 7.6 to 73.6 +/- 8.4 lbs) compared favorably with retention values from the literature for orthodontic bands cemented on permanent molar and premolar teeth. PMID:8153003

  8. 3D imaging reconstruction and impacted third molars: case reports

    PubMed Central

    Tuzi, Andrea; Di Bari, Roberto; Cicconetti, Andrea

    2012-01-01

    Summary There is a debate in the literature about the need for Computed Tomagraphy (CT) before removing third molars, even if positive radiographic signs are present. In few cases, the third molar is so close to the inferior alveolar nerve that its extraction might expose patients to the risk of post-operative neuro-sensitive alterations of the skin and the mucosa of the homolateral lower lip and chin. Thus, the injury of the inferior alveolar nerve may represent a serious, though infrequent, neurologic complication in the surgery of the third molars rendering necessary a careful pre-operative evaluation of their anatomical relationship with the inferior alveolar nerve by means of radiographic imaging techniques. This contribution presents two case reports showing positive radiographic signs, which are the hallmarks of a possible close relationship between the inferior alveolar nerve and the third molars. We aim at better defining the relationship between third molars and the mandibular canal using Dental CT Scan, DICOM image acquisition and 3D reconstruction with a dedicated software. By our study we deduce that 3D images are not indispensable, but they can provide a very agreeable assistance in the most complicated cases. PMID:23386934

  9. Thermal destruction of copolymers of polypropylene glycol maleate with acrylic acid

    NASA Astrophysics Data System (ADS)

    Burkeev, M. Zh.; Sarsenbekova, A. Zh.; Tazhbaev, E. M.; Figurinene, I. V.

    2015-12-01

    The results from thermogravimetric and kinetic studies of copolymers of polypropylene glycol maleate with acrylic acid at different molar ratios are presented. The results from conventional thermogravimetric studies are used to determine kinetic characteristics of the process of thermal decomposition, i.e., activation energy and pre-exponential factors. These parameters are determined in three ways: the Achar, Freeman-Carroll, and Sharp-Wentworth methods. Activation energies calculated using all the three methods confirm the dependence of the destruction process on the ratio of components in a synthesized copolymer. It is shown that the obtained values of the activation energies and thermodynamic characteristics allow us to predict a copolymer's composition.

  10. Comparison between the AA/EPA ratio in depressed and non depressed elderly females: omega-3 fatty acid supplementation correlates with improved symptoms but does not change immunological parameters

    PubMed Central

    2012-01-01

    Background Depression is one of the most frequently missed diagnoses in elderly people, with obvious negative effects on quality of life. Various studies have shown that long chain omega-3 polyunsaturated fatty acids (n-3 PUFA) may be useful in its management. Our objective was to evaluate whether a supplement containing n-3 PUFA improves depressive symptoms in depressed elderly patients, and whether the blood fatty acid pattern is correlated with these changes. Methods The severity of depressive symptoms according to the Geriatric Depression Scale (GDS), blood fatty acid composition and erythrocyte phospholipids were analyzed in 46 depressed females aged 66-95y, diagnosed with depression according to DSMIV, within the context of a randomized, double-blind, placebo-controlled trial. 22 depressed females were included in the intervention group (2.5 g/day of n-3 PUFA for 8 weeks), and 24 in the placebo group. We also measured immunological parameters (CD2, CD3, CD4, CD8, CD16, CD19 and cytokines (IL-5, IL-15). Results The mean GDS score and AA/EPA ratio, in whole blood and RBC membrane phospholipids, were significantly lower after 2 months supplementation with n-3 PUFA. A significant correlation between the amelioration of GDS and the AA/EPA ratio with some immunological parameters, such as CD2, CD19, CD4, CD16 and the ratio CD4/CD8, was also found. Nevertheless, omega-3 supplementation did not significantly improve the studied immunological functions. Conclusions n-3 PUFA supplementation ameliorates symptoms in elderly depression. The n-3 PUFA status may be monitored by means of the determination of whole blood AA/EPA ratio. PMID:23046564

  11. Measurement of strontium isotope ratio in nitric acid extract of peanut testa by ICP-Q-MS after removal of Rb by extraction with pure water.

    PubMed

    Zhu, Yanbei; Hioki, Akiharu; Chiba, Koichi

    2014-02-01

    The difference in the distributions of Sr and Rb in peanut seeds was utilized to develop a precise method for Sr isotope ratio measurement by inductively coupled plasma quadruple mass spectrometry (ICP-Q-MS). The testa instead of the whole peanut seed was selected as the sample because apparent enrichment of Sr in comparison to Rb was found in the testa. Furthermore, Rb in the testa was removed by pure water extraction with the aid of sonication to remove the isobaric interference in Sr isotope ratio measurement. The testa taken from one peanut seed was treated as one sample for the analysis. After optimization of the operating conditions, pure water (10 mL for each sample) extraction in 30 min with sonication was able to remove over 95% of Rb in the testa, while after the Rb removal Sr could be completely extracted using 10 mL of 0.3 mol L(-1) HNO3 for each sample. The integration time in ICP-Q-MS measurement was optimized to achieve a lower measurement uncertainty in a shorter time; the results showed that 1s was required and enough for the precise measurement of Sr isotope ratios giving a relative standard uncertainty (n=10) of ca. 0.1%. The present method was applied to peanut seeds grown in Japan, China, USA, India, and South Africa. PMID:24401460

  12. Pendulum Therapy of Molar Distalization in Mixed Dentition.

    PubMed

    Patil, Raju Umaji; Prakash, Amit; Agarwal, Anshu

    2016-01-01

    Early and timely pedo-orthodontic treatment is aimed at eliminating the disturbances of skeletal or dentoalveolar development, to harmonize the stomatognathic system before the full eruption of all permanent teeth. The advantages of pendulum appliance are its minimal dependence on patient's compliance (child cooperation), ease of fabrication, onetime activation and adjustment of the springs if necessary to correct minor transverse and vertical molar positions. This article reports a successful treatment method of class II malocclusion with pendulum appliance in mixed dentition phase. Distalization of maxillary molar was done, followed by guidance of canine impaction orthodontically and other dental correction using 0.022 MBT appliances. Posttreatment results were stable and remarkable. How to cite this article: Patil RU, Prakash A, Agarwal A. Pendulum Therapy of Molar Distalization in Mixed Dentition. Int J Clin Pediatr Dent 2016;9(1):67-73. PMID:27274159

  13. Pendulum Therapy of Molar Distalization in Mixed Dentition

    PubMed Central

    Prakash, Amit; Agarwal, Anshu

    2016-01-01

    ABSTRACT Early and timely pedo-orthodontic treatment is aimed at eliminating the disturbances of skeletal or dentoalveolar development, to harmonize the stomatognathic system before the full eruption of all permanent teeth. The advantages of pendulum appliance are its minimal dependence on patient’s compliance (child cooperation), ease of fabrication, onetime activation and adjustment of the springs if necessary to correct minor transverse and vertical molar positions. This article reports a successful treatment method of class II malocclusion with pendulum appliance in mixed dentition phase. Distalization of maxillary molar was done, followed by guidance of canine impaction orthodontically and other dental correction using 0.022 MBT appliances. Posttreatment results were stable and remarkable. How to cite this article: Patil RU, Prakash A, Agarwal A. Pendulum Therapy of Molar Distalization in Mixed Dentition. Int J Clin Pediatr Dent 2016;9(1):67-73. PMID:27274159

  14. Aberration in the palatal root of the maxillary first molar

    PubMed Central

    Rajalbandi, Sandeep; Shingte, Sandhya Narayan; Sundaresh, K J; Mallikarjuna, Rachappa

    2013-01-01

    Thorough knowledge of root canal morphology is essential for the endodontic therapy. Variations in the root and root canal morphology, especially in multirooted teeth, are a constant challenge for diagnosis and management. The dentist needs to be familiar with the various root canal configurations and their variations for successful endodontic therapy. There are rare variations in canal number and configuration in maxillary molars, which could affect treatment outcome. Two lingual root structures are occasionally found on human permanent maxillary molars. One of these is the normal lingual root, which is always present, the other is a supernumerary structure which can be located either mesiolingually (radix mesiolingualis) or distolingually (radix distolingualis). The purpose of this paper is to review the literature and to demonstrate a case report which describes the successful non-surgical endodontic management of an unusual maxillary first molar with four separate roots and four canals. PMID:23632609

  15. Molar enamel thickness and dentine horn height in Gigantopithecus blacki.

    PubMed

    Olejniczak, A J; Smith, T M; Wang, W; Potts, R; Ciochon, R; Kullmer, O; Schrenk, F; Hublin, J-J

    2008-01-01

    Absolutely thick molar enamel is consistent with large body size estimates and dietary inferences about Gigantopithecus blacki, which focus on tough or fibrous vegetation. In this study, 10 G. blacki molars demonstrating various stages of attrition were imaged using high-resolution microtomography. Three-dimensional average enamel thickness and relative enamel thickness measurements were recorded on the least worn molars within the sample (n = 2). Seven molars were also virtually sectioned through the mesial cusps and two-dimensional enamel thickness and dentine horn height measurements were recorded. Gigantopithecus has the thickest enamel of any fossil or extant primate in terms of absolute thickness. Relative (size-scaled) measures of enamel thickness, however, support a thick characterization (i.e., not "hyper-thick"); G. blacki relative enamel thickness overlaps slightly with Pongo and completely with Homo. Gigantopithecus blacki dentine horns are relatively short, similar to (but shorter than) those of Pongo, which in turn are shorter than those of humans and African apes. Gigantopithecus blacki molar enamel (and to a lesser extent, that of Pongo pygmaeus) is distributed relatively evenly across the occlusal surface compared with the more complex distribution of enamel thickness in Homo sapiens. The combination of evenly distributed occlusal enamel and relatively short dentine horns in G. blacki results in a flat and low-cusped occlusal surface suitable to grinding tough or fibrous food objects. This suite of molar morphologies is also found to varying degrees in Pongo and Sivapithecus, but not in African apes and humans, and may be diagnostic of subfamily Ponginae. PMID:17941103

  16. Sex assessment by molar odontometrics in North Indian population

    PubMed Central

    Narang, Ramandeep Singh; Manchanda, Adesh S.; Singh, Balwinder

    2015-01-01

    Introduction: Human identification is based on scientific principles, mainly involving dental records, fingerprints, estimation of age, postmortem reports, differentiation by blood groups, and DNA comparisons. Sex assessment is one of the prime factors employed to assist with the identification of an individual. Aims and Objective: To investigate univariate sex differences in the dimensions of permanent first molars and to assess sex, based on buccolingual (BL) and mesiodistal (MD) dimensions of permanent first molars in a population of north India. In addition, the study intended to evaluate the reliability of dimensional variation of these teeth in assessment of sex among the population. Materials and Methods: The study sample consists of 410 adult individuals (200 males and 210 females), from a north Indian population. The BL and MD diameters of the permanent first molars were measured using digital vernier callipers. Results: It was observed statistically significant difference between males and females with P < 0.05, in maxillary casts in both BL and MD dimensions; but only in the MD dimension in mandibular casts. A high level of sexual dimorphism of 7.7% was found in the BL dimension of the maxillary right first molar. The accuracy of sex assessment by each dimension was deliberated by univariate analyses with an overall accuracy ranging from 67.5 to 88% for various dimensions. Conclusion: Sexual dimorphism of teeth is population specific and among north Indian population, BL and MD dimensions in maxillary first molar and MD dimension in mandibular first molar can be used for sex assessment. PMID:25709321

  17. Enhanced Enzymatic Preparation of Biodiesel Using Ricinoleic Acid as Acyl Donor: Optimization Using Response Surface Methodology.

    PubMed

    Wang, Ping; Sun, Shangde

    2016-09-01

    Castor oil methyl ester is a kind of biodiesel from castor oil. However, in those previous methods for biodiesel preparation using castor oil as feedstock, glycerol was the main by-product, which had a strong blocking effect on the immobilized enzyme activity and affected the mass transfer of reaction system. For avoiding the negative effect of glycerol on the enzymatic esterification, biodiesel was prepared using ricinoleic acid (RA) as acyl donor. Enzyme screening was also studied, and the effects of reaction temperature, molar ratio of ricinoleic acid and methanol, enzyme load, and reaction time, on the preparation of castor methyl ester were also evaluated. Response surface methodology (RSM) was used to optimize the interaction effect of reaction variables (reaction temperature (30-70°C), enzyme load (2-7%; relative to the weight of total substrates), molar ratio of methanol to ricinoleic acid (2:1-10:1), and reaction time (0.5-2.5 h)) on the acid value (AV) and the degree of esterification (DE). Validation of the RSM model was verified by the good agreement between the experimental and the predicted values of AV and DE. The optimum preparation conditions were as follows: reaction temperature, 48.2°C; enzyme load, 5.8%; molar ratio of methanol to ricinoleic acid, 5.56:1; reaction time, 2.36 h. Under these conditions, the AV and DE of the esterification reaction are 10.36±1.05 mgKOH/g and 94.03±0.60%, respectively. The relationship between initial reaction rate and temperature was also established, and the activation energy (Ea) of the enzymatic esterification is 33.87 KJ/mol. PMID:27477073

  18. Immobilization of lead in anthropogenic contaminated soils using phosphates with/without oxalic acid.

    PubMed

    Su, Xiaojuan; Zhu, Jun; Fu, Qingling; Zuo, Jichao; Liu, Yonghong; Hu, Hongqing

    2015-02-01

    Understanding the effects of oxalic acid (OA) on the immobilization of Pb(II) in contaminated soils by phosphate materials, has considerable benefits for risk assessment and remediation strategies for the soil. A series of phosphate amendments with/without oxalic acid were applied to two anthropogenic contaminated soils. We investigated the immobilization of Pb(II) by KH2PO4, phosphate rock (PR), activated phosphate rock (APR) and synthetic hydroxyapatite (HAP) at different phosphate:Pb (P:Pb) molar ratios (0, 0.6, 2.0 and 4.0) in the presence/absence of 50 mmol oxalic acid/kg soil, respectively. The effects of treatments were evaluated using single extraction with deionized water or CaCl2, Community Bureau of Reference (BCR) sequential extraction and toxicity characteristic leaching procedure (TCLP) methods. Our results showed that the concentration of water extractable, exchangeable and TCLP-Pb all decreased with incubation time. The concentration of water-extractable Pb after 120 days was reduced by 100% when soils were amended with APR, HAP and HAP+OA, and the TCLP-Pb was <5 mg/L for the red soil at P:Pb molar ratio 4.0. Water-soluble Pb could not be detected and the TCLP-Pb was <5 mg/L at all treatments applied to the yellow-brown soil. BCR results indicated that APR was most effective, although a slight enhancement of water-soluble phosphate was detected at the P:Pb molar ratio 4.0 at the beginning of incubation. Oxalic acid activated phosphates, and so mixing insoluble phosphates with oxalic acid may be a useful strategy to improve their effectiveness in reducing Pb bioavailability. PMID:25662240

  19. Developmental and spatial variations in the diet signatures of hyperbenthic shrimp Nauticaris marionis at the Prince Edward Islands based on stable isotope ratios and fatty acid profiles

    NASA Astrophysics Data System (ADS)

    Richoux, Nicole B.; Allan, E. Louise; Froneman, P. William

    2016-04-01

    The caridean shrimp Nauticaris marionis is an ecologically important species in the benthic community around the sub-Antarctic Prince Edward Islands (PEI) as it represents a key prey item for a variety of top predators breeding on the islands. We hypothesized that the diet of N. marionis shifts during its development, and that spatial variability in food availability results in differentiation in the diet signatures of specimens collected from various locations of the shelf waters around the PEI. Specimens were collected from nine stations (depth range 70 to 240 m) around the PEI at inter-island shelf (from west to east: upstream, between and downstream) and nearshore regions during austral autumn 2009. Stable isotope and fatty acid data both revealed spatial and developmental variations in the shrimp diet. Nearshore shrimp were more 13C-enriched than those from the inter-island region, suggesting increased kelp detritus entered the food web in the nearshore regions. The shrimp showed increases in δ13C and δ15N signatures (and trophic position) with an increase in body size, resulting in distinctions between size classes that reflected shifts in their trophic niche through development. The fatty acid profiles similarly indicated distinctions in diet with increased shrimp size (in the deep regions), and spatial variability was evident in relation to region and depth. All shrimp contained large proportions of polyunsaturated and essential fatty acids, indicating that the quality of food consumed was similar between regions despite the diet variability. Our results provide new dietary information about a key species operating near the base of the food web at the highly productive PEI, and show that there were no areas of enhanced nutrition available to the shrimp. As such, there was no nutritional advantage to shrimp inhabiting any specific region around the PEI.

  20. Early prediction of mandibular third molar eruption/impaction using linear and angular measurements on digital panoramic radiography: A radiographic study

    PubMed Central

    Kaur, Rachninder; Kumar, Anand C.; Garg, Ranjana; Sharma, Sugandha; Rastogi, Trisha; Gupta, Vivek Vijay

    2016-01-01

    Background: The impaction rate is higher for the third molars than for any other tooth in modern human population. This study was conducted with the aim to evaluate the validity of linear and angular measurements on the digital panoramic radiograph as a reference for early prediction of mandibular third molar eruption/impaction. Materials and Methods: Digital panoramic radiographs of 200 subjects were selected based on their status of eruption of mandibular third molars; fully erupted (Group A), partially erupted (Group B), fully developed but not erupted (Group C) and partially developed groups (Group D). Each group comprised 50 subjects with 25 males and 25 females. Nine variables (linear measurements, angles, and ratios) were determined and measured bilaterally by two observers and values were compared between the study groups and genders. Results: The data thus obtained were analyzed for comparison among all the study groups. It was found that the difference in the mean values of lower eruption space (LES) measurements, α-angle (angle between long axis of the third molar and gonial-symphyseal plane) and β-angle (angle between long axis of mandibular second and third molars) were significant (P < 0.05). The mean values of mesiodistal width, LES-ramus, LES-Xi point and β-angle were found more in males than in females. No significant difference was observed between the sides. Conclusion: α- and β-angle together with LES measurements give the accurate information on early prediction of lower third molar eruption or impaction. PMID:27433048

  1. Mildly abnormal general movement quality in infants is associated with higher Mead acid and lower arachidonic acid and shows a U-shaped relation with the DHA/AA ratio.

    PubMed

    van Goor, S A; Schaafsma, A; Erwich, J J H M; Dijck-Brouwer, D A J; Muskiet, F A J

    2010-01-01

    We showed that docosahexaenoic acid (DHA) supplementation during pregnancy and lactation was associated with more mildly abnormal (MA) general movements (GMs) in the infants. Since this finding was unexpected and inter-individual DHA intakes are highly variable, we explored the relationship between GM quality and erythrocyte DHA, arachidonic acid (AA), DHA/AA and Mead acid in 57 infants of this trial. MA GMs were inversely related to AA, associated with Mead acid, and associated with DHA/AA in a U-shaped manner. These relationships may indicate dependence of newborn AA status on synthesis from linoleic acid. This becomes restricted during the intrauterine period by abundant de novo synthesis of oleic and Mead acids from glucose, consistent with reduced insulin sensitivity during the third trimester. The descending part of the U-shaped relation between MA GMs and DHA/AA probably indicates DHA shortage next to AA shortage. The ascending part may reflect a different developmental trajectory that is not necessarily unfavorable. PMID:20022733

  2. The urinary ratio of 3-hydroxykynurenine/3-hydroxyanthranilic acid is an index to predicting the adverse effects of D-tryptophan in rats.

    PubMed

    Shibata, Katsumi; Ohno, Tomoaki; Sano, Mitsue; Fukuwatari, Tsutomu

    2014-01-01

    The adverse effects of D-tryptophan and the possibility of it being a surrogate index for predicting adverse effects in rats were investigated. Male rats were fed one of several test diets (20% casein diets with 0% (control), 0.1%, 0.2%, 0.3%, 0.4%, and 0.5% D-tryptophan) for 21 d, and 24-h urine samples on the final day of the experiment were collected. Analyses of food intake and body-weight changes revealed adverse effects to be observed in the group fed the 0.3% D-tryptophan diet. We propose urinary levels of 3-hydroxykynurenine/3-hydroxyanthranilic acid to be surrogate indicators for predicting the adverse effects of D-tryptophan from the break point of body-weight gains and urinary levels of D-tryptophan metabolites. The reaction 3-hydroxykynurenine→3-hydroxyanthranilic acid is catalyzed by the pyridoxal phosphate-dependent enzyme kynureninase. Increasing urinary 3-hydrokykynurenine indicates kynureninase deficiency. Intake of D-tryptophan in rats fed the 0.3% D-tryptophan diet was 0.21 g/kg body weight and feeding of the 0.3% D-tryptophan diet did not elicit adverse effects. Thus, the safe level of D-tryptophan was less than 0.2% in the diet, 0.15 g/kg body weight, in rats. PMID:25297615

  3. Relevance of the carnosic acid/carnosol ratio for the level of rosemary diterpene transfer and for improving lamb meat antioxidant status.

    PubMed

    Jordán, María J; Castillo, Julián; Bañón, Sancho; Martínez-Conesa, Cristina; Sotomayor, José A

    2014-05-15

    The aim of the present work was to evaluate whether the relation between the concentrations of the two major diterpenes present in two typified rosemary extracts affects their levels of deposition and antioxidant capacity in different lamb tissues. The composition of the extracts expressed as percentage of weight/weight was 1:1 (14-16)% and 2:1 (25-11)% (carnosic acid-carnosol), respectively. Thirty weaned lambs were assigned randomly to three homogeneous groups. One group was fed a basal diet as a control and the diets of the other two were enriched with rosemary extracts 1:1 and 2:1, respectively. HPLC-ESI-MS/TOF identified a metabolite (C19H22O3) described for the first time in lamb tissues, along with carnosol, carnosic acid, rosmanol and carnosol-p-quinone. The results obtained corroborate the importance of the presence of carnosol in the dietary administration of rosemary extract as a way of improving the stability of the diterpene fraction during feed manufacturing and the level of deposition and antioxidant efficacy of diterpenes after ruminal fermentation. PMID:24423523

  4. Evaluation of skeletal and dental age using third molar calcification, condylar height and length of the mandibular body

    PubMed Central

    Kedarisetty, Sunil Gupta; Rao, Guttikonda Venkateswara; Rayapudi, Naveen; Korlepara, Rajani

    2015-01-01

    Aim: To identify the most reliable method for age estimation among three variables, that is, condylar height, length of mandibular body and third molar calcification by Demirjian's method. Materials and Methods: Orthopantomograms and lateral cephalograms of 60 patients with equal gender ratio were included in the study, among each gender 15 subjects were below 18 years and 15 subjects were above 18 years. Lateral cephalograms were traced, height of condyle and mandibular body are measured manually on the tracing paper, OPG's were observed on radiographic illuminator and maturity score of third molar calcification was noted according to Demirjian's method. All the measurements were subjected to statistical analysis. Results: The results obtained are of no significant difference between estimated age and actual age with all three parameters (P > 0.9780 condylar height, P > 0.9515 length of mandibular body, P > 0.8611 third molar calcification). Among these three, length of mandibular body shows least standard error test (i.e. 0.188). Conclusion: Although all three parameters can be used for age estimation, length of mandibular body is more reliable followed by height of condyle and third molar calcification. PMID:26005300

  5. Procedures to recover DNA from pre-molar and molar teeth of decomposed cadavers with different post-mortem intervals.

    PubMed

    Raimann, Paulo E; Picanço, Juliane B; Silva, Deborah S B S; Albuquerque, Trícia C K; Paludo, Francis Jackson O; Alho, Clarice S

    2012-11-01

    A task-force to resolve 26 pending forensic caseworks was carried out. We tested four different protocols to extract DNA from molar and pre-molar teeth from 26 cadavers with post-mortem intervals from 2 months to 12 years. We compared the amount of DNA and DNA profiles with the time elapsed between death and laboratory procedures. Molar or pre-molar teeth were removed from the corpses, cleaned, and DNA was extracted using 2 or 12h of incubation on lysis buffer and filtered using concentration column or precipitated with isopropanol. DNA profiles were obtained using PowerPlex16™ System PCR Amplification Kit, AmpFlSTR(®) Yfiler™ and/or mtDNA sequencing. Complete DNA profiles comparison and statistical evaluation allowed unambiguous identification of the 26 victims. No significant differences were observed in the amount of DNA obtained with the distinct incubation times. The use of concentration column resulted in an increased amount of DNA when compared to isopropanol. However, the lower concentration of DNA obtained with isopropanol seemed to have been compensated by the higher purity. No significant differences in the number of amplified loci were found. A non-significant tendency was found between the amount of total DNA recovered and the time elapsed between death and laboratory procedures. The increase of post-mortem time did not interfere in the analysed autosomal loci. In conclusion, molar and pre-molar teeth were shown to be good candidates to obtain satisfactory DNA profiles, suggesting the high potential of tooth samples as source for DNA typing independently of the decomposed corpse's time or laboratory procedures. PMID:23040740

  6. Design of an effective bifunctional catalyst organotriphosphonic acid-functionalized ferric alginate (ATMP-FA) and optimization by Box-Behnken model for biodiesel esterification synthesis of oleic acid over ATMP-FA.

    PubMed

    Liu, Wei; Yin, Ping; Liu, Xiguang; Qu, Rongjun

    2014-12-01

    Biodiesel production has become an intense research area because of rapidly depleting energy reserves and increasing petroleum prices together with environmental concerns. This paper focused on the optimization of the catalytic performance in the esterification reaction of oleic acid for biodiesel production over the bifunctional catalyst organotriphosphonic acid-functionalized ferric alginate ATMP-FA. The reaction parameters including catalyst amount, ethanol to oleic acid molar ratio and reaction temperature have been optimized by response surface methodology (RSM) using the Box-Behnken model. It was found that the reaction temperature was the most significant factor, and the best conversion ratio of oleic acid could reach 93.17% under the reaction conditions with 9.53% of catalyst amount and 8.62:1 of ethanol to oleic acid molar ratio at 91.0 °C. The research results show that two catalytic species could work cooperatively to promote the esterification reaction, and the bifunctional ATMP-FA is a potential catalyst for biodiesel production. PMID:25310862

  7. Overnight urinary uric acid: creatinine ratio for detection of sleep hypoxemia. Validation study in chronic obstructive pulmonary disease and obstructive sleep apnea before and after treatment with nasal continuous positive airway pressure.

    PubMed

    Braghiroli, A; Sacco, C; Erbetta, M; Ruga, V; Donner, C F

    1993-07-01

    During hypoxia ATP degradation to uric acid is increased in animal models and humans. To assess the reliability of an overnight increase in uric acid excretion as a marker of nocturnal hypoxemia, we selected 10 normal volunteers (7 males and 3 females), 29 COPD patients (26 males and 3 females), and 49 subjects with obstructive sleep apnea (OSA) (43 males and 6 females). The patients underwent standard polysomnography, which was repeated in 14 subjects with nasal continuous positive airway pressure (CPAP), and were subdivided into two groups: Group D included desaturating subjects who spent at least 1 h at SaO2 < 90% and 15 min below 85%, and Group ND were nondesaturating subjects. The overnight change in the uric acid:creatinine ratio (delta UA:Cr) was negative in normal subjects (-27.5 +/- 9.1 [mean +/- SD]) and ND groups: -19.7 +/- 14.3 in COPD, -16.1 +/- 13.0 in OSA. In both COPD and OSA Group D, the ratio was usually positive: delta UA:Cr was 17.9 +/- 31.4 in Group D COPD (p < 0.001 versus ND) and 10.1 +/- 30.7 in Group D OSA (p < 0.001 versus ND and versus normal subjects) despite 4 of 15 false negative results in COPD and 8 of 20 in OSA. CPAP effective treatment induced a marked reduction ((p = 0.0024) in delta UA:Cr, leading to a negative value. We conclude that delta UA:Cr seems to be a promising index of significant nocturnal tissue hypoxia, with good specificity but poor sensitivity (about 30% false negative), which might be useful for the long-term follow-up of outpatients on nasal CPAP with a positive ratio at baseline. PMID:8317794

  8. Recovery of calcium carbonate from waste gypsum and utilization for remediation of acid mine drainage from coal mines.

    PubMed

    Mulopo, J; Radebe, V

    2012-01-01

    The recovery of calcium carbonate from waste gypsum (a waste product of the reverse osmosis (RO) desalination process) was tested using sodium carbonate. Batch recovery of calcium carbonate from waste gypsum slurries by reacting with sodium carbonate under ambient conditions was used to assess the technical feasibility of CaCO(3) recovery and its use for pre-treatment of acid mine drainage (AMD) from coal mines. The effect of key process parameters, such as the slurry concentration (%) and the molar ratio of sodium carbonate to gypsum were considered. It was observed that batch waste gypsum conversion significantly increased with decrease in the slurry concentration or increase in the molar ratio of sodium carbonate to gypsum. The CaCO(3) recovered from the bench-scale batch reactor demonstrated effective neutralization ability during AMD pre-treatment compared with commercial laboratory grade CaCO(3). PMID:22828309

  9. Determination of the solubility of crystalline low molar mass compounds in polymers by differential scanning calorimetry.

    PubMed

    Rager, Timo

    2014-06-01

    A mathematical equation has been derived to calculate the liquidus for a binary system consisting of an amorphous polymer and a crystalline low molar mass compound. The experimental input to this equation is an interaction enthalpy, which is derived from the variation of the melting enthalpy with composition in differential scanning calorimetry (DSC) experiments. The predictive power of the equation has been tested with mixtures of acetylsalicylic acid, carbamazepine, or intraconazole with poly(ethylene glycol) as well as mixtures of carbamazepine with poly(acrylic acid), poly(hydroxystyrene), or poly(vinylpyrrolidone). It has been confirmed that the evaluation of the melting enthalpy in DSC is a suitable method to identify the preferred solute-polymer combinations for thermodynamically stable molecular dispersions. PMID:24723307

  10. Management of Six Root Canals in Mandibular First Molar

    PubMed Central

    Gomes, Fabio de Almeida; Sousa, Bruno Carvalho

    2015-01-01

    Success in root canal treatment is achieved after thorough cleaning, shaping, and obturation of the root canal system. This clinical case describes conventional root canal treatment of an unusual mandibular first molar with six root canals. The prognosis for endodontic treatment in teeth with abnormal morphology is unfavorable if the clinician fails to recognize extra root canals. PMID:25685156

  11. The effect of dexamethasone on neurapraxia following third molar surgery.

    PubMed

    Von Arx, D P; Simpson, M T

    1989-12-01

    A double blind, controlled trial was undertaken to assess the effect of intra-muscular dexamethasone on neurapraxia following the surgical removal of mandibular third molars. No significant difference was found 24 h post-operatively between a control group and a group given dexamethasone. PMID:2597658

  12. Survival rates of porcelain molar crowns-an update.

    PubMed

    Kassem, Amr Shebl; Atta, Osama; El-Mowafy, Omar

    2010-01-01

    The aim of this study was to identify recent studies that dealt with the clinical performance of porcelain molar crowns and to explore the possibility of grouping the findings from similar studies together to draw overall conclusions. A MEDLINE literature search was conducted in early 2009 covering the preceding 12 years. Seventeen studies were indentified. However, only seven met the specific inclusion criteria and were analyzed. Among seven studies, five European countries were covered. Five studies reported on Procera AllCeram molar crowns while one reported on In-Ceram Alumina and Spinell crowns and another on CEREC crowns. For comparison, one additional study that reported on premolar crowns was included. In the five Procera AllCeram studies, 235 molar crowns were evaluated for 5 or more years, of which 24 failed. When the results of the five studies on the performance of Procera AllCeram molar crowns were considered collectively, an overall failure rate of 10.2% was found at 5 or more years. Int J Prosthodont 2010;23:60-62. PMID:20234895

  13. A cervical ectopic masquerading as a molar pregnancy.

    PubMed

    Masir, N; Tamby, M R; Jamil, M A

    2000-03-01

    We report a case of cervical pregnancy complicated by life threatening hemorrhage. An initial diagnosis of molar pregnancy was made preoperatively. During uterine evacuation she developed profuse hemorrhage which required an emergency hysterectomy for uncontrolled bleeding. Histopathological examination confirmed a cervical pregnancy. The clinical and pathological criteria for the diagnosis and the etiology of cervical pregnancy are discussed. PMID:11072500

  14. Anterior tympanic plate fracture following extraction of the lower molar

    PubMed Central

    2016-01-01

    The present case report describes an external auditory canal injury following extraction of the lower molar. The external auditory canal was torn in the same fashion that occurs in an anterior tympanic plate fracture. This case demonstrates one of the rare complications associated with dental extractions. PMID:26904496

  15. Intrusion of overerupted molars by corticotomy and magnets.

    PubMed

    Hwang, H S; Lee, K H

    2001-08-01

    Although posterior tooth intrusion in an adult patient is a difficult procedure, it can be achieved without extruding the adjacent teeth by performing a corticotomy and using magnets. In carrying out this procedure on 2 adult patients whose molars had overerupted due to the early loss of antagonists, tooth movement was rapidly achieved without discomfort or side effects. PMID:11500664

  16. Lower molar and incisor displacement associated with mandibular remodeling.

    PubMed

    Baumrind, S; Bravo, L A; Ben-Bassat, Y; Curry, S; Korn, E L

    1997-01-01

    The purpose of this study was to quantify the amount of alveolar modeling at the apices of the mandibular incisor and first molar specifically associated with appositional and resorptive changes on the lower border of the mandible during growth and treatment. Cephalometric data from superimpositions on anterior cranial base, mandibular implants of the Björk type, and anatomical "best fit" of mandibular border structures were integrated using a recently developed strategy, which is described. Data were available at annual intervals between 8.5 and 15.5 years for a previously described sample of approximately 30 children with implants. The average magnitudes of the changes at the root apices of the mandibular first molar and central incisor associated with modeling/remodeling of the mandibular border and symphysis were unexpectedly small. At the molar apex, mean values approximated zero in both anteroposterior and vertical directions. At the incisor apex, mean values approximated zero in the anteroposterior direction and averaged less than 0.15 mm/year in the vertical direction. Standard deviations were roughly equal for the molar and the incisor in both the anteroposterior and vertical directions. Dental displacement associated with surface modeling plays a smaller role in final tooth position in the mandible than in the maxilla. It may also be reasonably inferred that anatomical best-fit superimpositions made in the absence of implants give a more complete picture of hard tissue turnover in the mandible than they do in the maxilla. PMID:9107373

  17. A Time for Heresy: A Molar Reading Model.

    ERIC Educational Resources Information Center

    Williamson, Leon E.

    A survey of the literature concerning the mental processes used in reading reveals a proliferation of molecular theories which explain only a small (and frequently neurological) component of the reading act. Enough information exists, however, to sketch an integrated, molar model of the reading process, which stresses the interrelationships…

  18. Non-compliance Appliances for Upper Molar Distalization: An Overview.

    PubMed

    Noorollahian, Saeed; Alavi, Shiva; Shirban, Farinaz

    2015-01-01

    Tooth Size Arch-length Discrepancy (TSALD) is a common problem in orthodontics. Its clinical signs are tooth crowding, impaction and incisor proclination. The treatment options are dental arch expansion or tooth mass reduction (stripping or extraction). The "extraction versus non-extraction" controversy has been widely debated in the orthodontic literature. Distalization is a kind of arch expansion in anetro-posterior dimension. Several studies have evaluated both the therapeutic effectiveness and the side effects of the appliances for this method of space gaining. In some cases molar distalization is preferred, e.g., a patient with acceptable profile and skeletal pattern and half cusp Class II molar malocclusion or even less. In some cases molar distalization is the only way, e.g., the patient with previous upper premolar extraction and excessive overijet, or a skeletal Class III patient with previous upper premolar extraction needed upper anterior teeth retraction to create reverse overjet aspre surgical orthodontic decompensation. In this review article, we described non-compliance upper molar distalizing appliances. PMID:26720949

  19. A High-Fat Diet Enriched with Low Omega-6 to Omega-3 Fatty Acid Ratio Reduced Fat Cellularity and Plasma Leptin Concentration in Sprague-Dawley Rats

    PubMed Central

    Tekeleselassie, A. W.; Goh, Y. M.; Rajion, M. A.; Motshakeri, M.; Ebrahimi, M.

    2013-01-01

    This study was aimed to investigate the effects of dietary fatty acids on the accretion pattern of major fat pads, inguinal fat cellularity, and their relation with plasma leptin concentration. Forty Sprague-Dawley rats were randomly assigned into four groups and received the following diets for 22 weeks: (1) standard rat chow diet (CTRL), (2) CTRL + 10% (w/w) butter (HFAR), (3) CTRL + 3.33% (w/w) menhaden fish oil + 6.67% (w/w) soybean oil (MFAR), and (4) CTRL + 6.67% (w/w) menhaden fish oil + 3.33% (w/w) soybean oil (LFAR). Inguinal fat cellularity and plasma leptin concentration were measured in this study. Results for inguinal fat cellularity showed that the mean adipocyte number for the MFAR (9.2 ∗ 105 ± 3.6) and LFAR (8.5 ∗ 105 ± 5.1) groups was significantly higher (P < 0.05) than the rest, while the mean adipocyte diameter of HFAR group was larger (P < 0.05) (46.2 ± 2.8) than the rest. The plasma leptin concentration in the HFAR group was higher (P < 0.05) (3.22 ± 0.32 ng/mL), than the other groups. The higher inguinal fat cellularity clearly indicated the ability of the polyunsaturated fatty acids (PUFA) and butter supplemented diets to induce hyperplasia and hypertrophy of fat cells, respectively, which caused adipocyte remodeling due to hyperleptinemia. PMID:24294136

  20. Effects of Si/Al Ratio on Cu/SSZ-13 NH3-SCR Catalysts: Implications for the active Cu species and the Roles of Brønsted Acidity

    SciTech Connect

    Gao, Feng; Washton, Nancy M.; Wang, Yilin; Kollar, Marton; Szanyi, Janos; Peden, Charles HF

    2015-09-03

    Cu/SSZ-13 catalysts with three Si/Al ratios of 6, 12 and 35 were synthesized with Cu incorporation via solution ion exchange. The implications of varying Si/Al ratios on the nature of the multiple Cu species that can be present in the SSZ-13 zeolite are a major focus of this work, as highlighted by the results of a variety of catalyst characterization and reaction kinetics measurements. Specifically, catalysts were characterized with surface area/pore volume measurements, temperature programmed reduction by H2 (H2-TPR), NH3 temperature programmed desorption (NH3-TPD), and DRIFTS and solid-state nuclear magnetic resonance (NMR) spectroscopies. Catalytic properties were examined using NO oxidation, ammonia oxidation, and standard ammonia selective catalytic reduction (NH3-SCR) reactions on selected catalysts under differential conditions. Besides indicating possible variably active multiple Cu species for these reactions, the measurements are also used to untangle some of the complexities caused by the interplay between redox of Cu ion centers and Brønsted acidity. All three reactions appear to follow a redox reaction mechanism, yet the roles of Brønsted acidity are quite different. For NO oxidation, increasing Si/Al ratio lowers Cu redox barriers, thus enhancing reaction rates. Brønsted acidity appears to play essentially no role for this reaction. For standard NH3-SCR, residual Brønsted acidity plays a significant beneficial role at both low- and high-temperature regimes. For NH3 oxidation, no clear trend is observed suggesting both Cu ion center redox and Brønsted acidity play important and perhaps competing roles. The authors gratefully acknowledge the US Department of Energy (DOE), Energy Efficiency and Renewable Energy, Vehicle Technologies Office for the support of this work. The research described in this paper was performed in the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the DOE’s Office of

  1. Metabolic Flux Between Unsaturated and Saturated Fatty Acids is Controlled by the FabA:FabB Ratio in the Fully Reconstituted Fatty Acid Biosynthetic Pathway of E. coli#

    PubMed Central

    Xiao, Xirui; Yu, Xingye; Khosla, Chaitan

    2013-01-01

    The entire fatty acid biosynthetic pathway from Escherichia coli, starting from the acetyl-CoA carboxylase, has been reconstituted in vitro from fourteen purified protein components. Radiotracer analysis verified stoichiometric conversion of acetyl-CoA and NAD(P)H into the free fatty acid product, allowing implementation of a facile spectrophotometric assay for kinetic analysis of this multi-enzyme system. At steady state, a maximum turnover rate of 0.5 s−1 was achieved. Under optimal turnover conditions, the predominant products were C16 and C18 saturated as well as monounsaturated fatty acids. The reconstituted system allowed us to quantitatively interrogate the factors that influence metabolic flux toward unsaturated versus saturated fatty acids. In particular, the concentrations of the dehydratase FabA and the β-ketoacyl synthase FabB were found to be crucial for controlling this property. By altering these variables, the percentage of unsaturated fatty acid produced could be adjusted between 10 and 50% without significantly affecting the maximum turnover rate of the pathway. Our reconstituted system provides a powerful tool to understand and engineer rate-limiting and regulatory steps in this complex and practically significant metabolic pathway. PMID:24147979

  2. The appropriate standardized ileal digestible tryptophan to lysine ratio improves pig performance and regulates hormones and muscular amino acid transporters in late finishing gilts fed low-protein diets.

    PubMed

    Ma, W F; Zhang, S H; Zeng, X F; Liu, X T; Xie, C Y; Zhang, G J; Qiao, S Y

    2015-03-01

    This study investigated the effects of various standardized ileal digestible (SID) Trp to Lys ratios on the performance and carcass characteristics of late finishing gilts receiving low-CP (9.6%) diets supplemented with crystalline AA. Ninety gilts (89.1 ± 5.1 kg) were used in a dose-response study conducted for 35 d. Crystalline Trp (0, 0.1, 0.2, 0.4, or 0.6 g/kg) was added to a corn-wheat bran basal diet providing SID Trp to Lys ratios of 0.12, 0.15, 0.18, 0.21, or 0.24. Each diet was fed to 6 pens of pigs with 3 gilts per pen. At the end of the experiment, 30 gilts (1 pig per pen) were slaughtered to evaluate carcass traits and meat quality (BW = 121 kg). Increasing the SID Trp to Lys ratio increased ADG (linear and quadratic effect, < 0.05) and also improved G:F (linear and quadratic effect, < 0.05). Serum urea nitrogen (SUN) decreased as the SID Trp to Lys ratio increased (linear and quadratic effects, < 0.05). A quadratic effect of L* light and marbling in the longissimus dorsi was observed as the dietary SID Trp to Lys ratio increased ( < 0.05). Increasing the SID Trp to Lys ratio increased the level of serum GH (quadratic effect, < 0.05) and also increased the level of serum IGF-1 (linear and quadratic effect, < 0.05). Increasing the SID Trp to Lys ratio increased the protein abundance of the muscular AA transporter of sodium-coupled neutral amino acid transporter 2 (SNAT2) in the longissimus dorsi muscle (linear and quadratic effect, < 0.05). The optimum SID Trp to Lys ratios to maximize ADG and G:F as well as to minimize SUN levels were 0.16, 0.17, and 0.16 using a linear-breakpoint model and 0.20, 0.20, and 0.20 using a quadratic model. Tryptophan could influence serum GH and IGF-1 secretion and protein abundance of the muscular AA transporter of SNAT2 in the longissimus dorsi muscle in late finishing gilts fed low-protein diets. PMID:26020882

  3. pH- and mol-ratio dependent formation of zinc(II) coordination polymers with iminodiacetic acid: synthesis, spectroscpic, crystal structure and thermal studies

    PubMed Central

    Ni, Lu-Bin; Zhang, Rong-Hua; Liu, Qiong-Xin; Xia, Wen-Sheng; Wang, Hongxin; Zhou, Zhao-Hui

    2009-01-01

    Three novel zinc coordination polymers (NH4)n[Zn(Hida)Cl2]n (1), [Zn(ida)(H2O)2]n (2), [Zn(Hida)2]n·4nH2O (3) (H2ida = iminodiacetic acid) and a monomeric complex [Zn(ida)(phen)(H2O)]·2H2O (4) (phen=1,10-phenanthroline) have been synthesized and characterized by X-ray diffraction methods. 1 and 2 form one-dimensional (1-D) chain structures, whereas 3 exhibits a three-dimensional (3-D) diamondoid framework with an open channel. The mononuclear complex 4 is extended into a 3-D supramolecular architecture through hydrogen bonds and π-π stacking. Interestingly, cyclic nonplanar tetrameric water clusters are observed that encapsulated in the 3-D lattice of 4. Based on 1H and 13C NMR observations, there is obvious coordination of complex 2 in solution, while 1 and 3 decompose into free iminodiacetate ligand. Monomer [Zn(ida)(H2O)3] (5) is considered as a possible discrete species from 2. These coordination polymers can serve as good molecular precursors for zinc oxide. PMID:20161370

  4. Mechanism of inactivation of. gamma. -aminobutyrate aminotransferase by 4-amino-5-fluoropentanoic acid. First examples of an enamine mechanisms for a. gamma. -amino acid with a partition ratio of 0

    SciTech Connect

    Silverman, R.B.; Invergo, B.J.

    1986-11-04

    The mechanism of inactivation of pig brain ..gamma..-aminobutyric acid aminotransferase (GABA-T) by (S)-4-amino-5-fluoropentanoic acid (1, R = CH/sub 2/CH/sub 2/COOH, X = F) previously proposed is revised. apo-GABA-T is reconstituted with (4-/sup 3/H)pyridoxal 5'-phosphate and inactivated with 1 (R = CH/sub 2/CH/sub 2/COOH, X = F). Treatment of inactivated enzyme with base followed by acid denaturation leads to the complete release of radioactivity as 6-(2-hydroxy-3-methyl-6-(phosphonoxymethyl)-4-pyridinyl)-4-oxo-5-hexenoic acid (4, R = CH/sub 2/CH/sub 2/COOH). Alkaline phosphatase treatment of this compound produces dephosphorylated 4 (R = CH/sub 2/CH/sub 2/COOH). These results support a mechanism that was suggested by Metzler and co-workers for the inactivation of glutamate decarboxylase by serine O-sulfate (Scheme I, pathway b, R = COOH, X - OSO/sub 3//sup -/).

  5. Morphology and Composition of Structured, Phase-Separated Behenic Acid-Perfluorotetradecanoic Acid Monolayer Films.

    PubMed

    Rehman, Jeveria; Araghi, Hessamaddin Younesi; He, Anqiang; Paige, Matthew F

    2016-05-31

    The phase separation of immiscible surfactants in mixed monolayer films provides an approach to physically manipulate important properties of thin films, including surface morphology, microscale composition, and mechanical properties. In this work, we predict, based upon existing miscibility studies and their thermodynamic underpinnings described in the literature, the miscibility and film morphology of mixed monolayers comprised of behenic acid (C21H43COOH) and perfluorotetradecanoic acid (C13F27COOH) in various molar ratios. Predictions are tested using a combination of experimental surface characterization methods for probing miscibility and film morphology at the solid/air and air/water interfaces. Film components were immiscible and phase-separated into chemically well-defined domains under a variety of experimental conditions, with monolayer morphology consistent with initial predictions. The extensibility of these basic predictions to other systems is discussed in the context of using these works for different perfluorinated surfactant molecules. PMID:27163482

  6. Evaluation of diagnostic accuracy and dimensional measurements by using CBCT in mandibular first molars

    PubMed Central

    Asgary, Saeed; Nikneshan, Sima; Akbarzadeh-Bagheban, Alireza

    2016-01-01

    Background This study aimed to assess the diagnostic accuracy of cone beam computed tomography (CBCT) and quantitatively evaluate the morphology of mandibular first molars using CBCT. Material and Methods Twenty-four double-rooted mandibular first molars were evaluated by NewTom VGi CBCT. The distance from the furcation and apex to the cementoenamel junction (CEJ), diameter and thickness of canal walls, the buccolingual (BL) to mesiodistal (MD) ratio (ΔD), prevalence of oval canals at different sections and taper of the canals were all determined. In order to assess the diagnostic accuracy of CBCT, distance from the furcation and apex to the CEJ and thickness of canal walls at the CEJ and apex were compared with the gold standard values (caliper and stereomicroscope). Statistical analyses were carried out using intraclass correlation coefficient (ICC), paired t-test and repeated measures ANOVA. Results A high correlation existed between the CBCT and gold standard measurements (P<0.001). In dimensional measurements, length of mesial root was higher than the distal root and lingual furcation was farther from the CEJ than the buccal furcation (P<0.001). An important finding of this study was the mesiodistal taper of the mesiobuccal (MB) and mesiolingual (ML) canals; which was equal to 0.02. Conclusions CBCT has acceptable diagnostic accuracy for measurement of canal wall thickness. Cleaning and shaping of the canals should be performed based on the unique anatomy of the respective canal; which necessitates the use of advanced imaging techniques for thorough assessment of root canal anatomy in a clinical setting. Key words:Permanent mandibular first molar, accuracy, cone-beam computed tomography, dimensional measurement. PMID:26855697

  7. Sulfuric acid functional zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts for alkylation of phenol with tert-butyl alcohol

    NASA Astrophysics Data System (ADS)

    Jiang, Tingshun; Cheng, Jinlian; Liu, Wangping; Fu, Lie; Zhou, Xuping; Zhao, Qian; Yin, Hengbo

    2014-10-01

    Several zirconium (or aluminum) incorporated mesoporous MCM-48 solid acid catalysts (SO42-/Zr-MCM-48 and SO42-/Al-MCM-48) were prepared by the impregnation method and their physicochemical properties were characterized by means of XRD, FT-IR, TEM, NH3-TPD and N2 physical adsorption. Also, the catalytic activities of these solid acid catalysts were evaluated by the alkylation of phenol with tert-butyl alcohol. The effect of weight hour space velocity (WHSV), reaction time and reaction temperature on catalytic properties was also studied. The results show that the SO42-/Zr-MCM-48 and SO42-/Al-MCM-48 still have good mesoporous structure and long range ordering. Compared with the Zr (or Al)-MCM-48 samples, SO42-/Zr-MCM-48 and SO42-/Al-MCM-48 solid acid catalysts have strong acidity and exhibit high activities in alkylation reaction of phenol with tert-butyl alcohol. The SO42-/Zr-MCM-48-25 (molar ratio of Si/Zr=0.04) catalyst was found to be the most promising and gave the highest phenol conversion among all catalysts. A maximum phenol conversion of 91.6% with 4-tert-butyl phenol (4-TBP) selectivity of 81.8% was achieved when the molar ratio of tert-butyl alcohol:phenol is 2:1, reaction time is 2 h, the WHSV is 2 h-1 and the reaction temperature is 140 °C.

  8. Corticotomy-assisted molar protraction with the aid of temporary anchorage device.

    PubMed

    Uribe, Flavio; Janakiraman, Nandakumar; Fattal, Amine N; Schincaglia, Gian Pietro; Nanda, Ravindra

    2013-11-01

    This case report describes the interdisciplinary management of a 58-year-old woman who was missing lower first molars and supraerupted maxillary first molars. The treatment plan included intrusion of the upper first molars and corticotomy-assisted mandibular second molar protraction with the aid of temporary anchorage devices. Miniscrews were effective in intrusion of the maxillary first molars and protraction of the lower second molars. Although good functional outcome was achieved in 41 months, the corticotomy-assisted procedure did not significantly reduce the treatment time. PMID:23834274

  9. Spectroscopic investigation and computational analysis of charge transfer hydrogen bonded reaction between 3-aminoquinoline with chloranilic acid in 1:1 stoichiometric ratio

    NASA Astrophysics Data System (ADS)

    Al-Ahmary, Khairia M.; Alenezi, Maha S.; Habeeb, Moustafa M.

    2015-10-01

    Charge transfer hydrogen bonded reaction between the electron donor (proton acceptor) 3-aminoquinoline with the electron acceptor (proton donor) chloranilic acid (H2CA) has been investigated experimentally and theoretically. The experimental work included the application of UV-vis spectroscopy to identify the charge transfer band of the formed complex, its molecular composition as well as estimating its formation constants in different solvent included acetonitrile (AN), methanol (MeOH), ethanol (EtOH) and chloroform (CHL). It has been recorded the presence of new absorption bands in the range 500-550 nm attributing to the formed complex. The molecular composition of the HBCT complex was found to be 1:1 (donor:acceptor) in all studied solvents based on continuous variation and photometric titration methods. In addition, the calculated formation constants from Benesi-Hildebrand equation recorded high values, especially in chloroform referring to the formation of stable HBCT complex. Infrared spectroscopy has been applied for the solid complex where formation of charge and proton transfer was proven in it. Moreover, 1H and 13C NMR spectroscopies were used to characterize the formed complex where charge and proton transfers were reconfirmed. Computational analysis included the use of GAMESS computations as a package of ChemBio3D Ultr12 program were applied for energy minimization and estimation of the stabilization energy for the produced complex. Also, geometrical parameters (bond lengths and bond angles) of the formed HBCT complex were computed and analyzed. Furthermore, Mullikan atomic charges, molecular potential energy surface, HOMO and LUMO molecular orbitals as well as assignment of the electronic spectra of the formed complex were presented. A full agreement between experimental and computational analysis has been found especially in the existence of the charge and proton transfers and the assignment of HOMO and LUMO molecular orbitals in the formed complex as

  10. Transgenic Increase in n-3/n-6 Fatty Acid Ratio Protects Against Cognitive Deficits Induced by an Immune Challenge through Decrease of Neuroinflammation

    PubMed Central

    Delpech, Jean-Christophe; Madore, Charlotte; Joffre, Corinne; Aubert, Agnès; Kang, Jing Xuan; Nadjar, Agnès; Layé, Sophie

    2015-01-01

    Polyunsaturated fatty acids (PUFAs) display immunomodulatory properties in the brain, n-3 PUFAs being able to reduce inflammation whereas n-6 PUFAs are more pro-inflammatory. It has been extensively demonstrated that exposure to a peripheral immune challenge leads to the production and release of inflammatory mediators in the brain in association with cognitive deficits. The question arises whether n-3 PUFA supplementation could downregulate the brain inflammatory response and subsequent cognitive alterations. In this study, we used a genetically modified mouse line carrying the fat-1 gene from the roundworm Caenorhabditis elegans, encoding an n-3 PUFA desaturase that catalyzes conversion of n-6 into n-3 PUFA. Consequently, these mice display endogenously elevated n-3 PUFA tissue contents. Fat-1 mice or wild-type (WT) littermates were injected peripherally with lipopolysaccharide (LPS), a bacterial endotoxin, to induce an inflammatory episode. Our results showed that LPS altered differently the phenotype of microglia and the expression of cytokines and chemokines in Fat-1 and WT mice. In Fat-1 mice, pro-inflammatory factors synthesis was lowered compared with WT mice, whereas anti-inflammatory mechanisms were favored 24 h after LPS treatment. Moreover, LPS injection impaired spatial memory in WT mice, whereas interestingly, the Fat-1 mice showed normal cognitive performances. All together, these data suggest that the central n-3 PUFA increase observed in Fat-1 mice modulated the brain innate immune system activity, leading to the protection of animals against LPS-induced pro-inflammatory cytokine production and subsequent spatial memory alteration. PMID:25228141

  11. Piezoelectric Versus Conventional Rotary Techniques for Impacted Third Molar Extraction

    PubMed Central

    Jiang, Qian; Qiu, Yating; Yang, Chi; Yang, Jingyun; Chen, Minjie; Zhang, Zhiyuan

    2015-01-01

    Abstract Impacted third molars are frequently encountered in clinical work. Surgical removal of impacted third molars is often required to prevent clinical symptoms. Traditional rotary cutting instruments are potentially injurious, and piezosurgery, as a new osteotomy technique, has been introduced in oral and maxillofacial surgery. No consistent conclusion has been reached regarding whether this new technique is associated with fewer or less severe postoperative sequelae after third molar extraction. The aim of this study was to compare piezosurgery with rotary osteotomy techniques, with regard to surgery time and the severity of postoperative sequelae, including pain, swelling, and trismus. We conducted a systematic literature search in the Cochrane Library, PubMed, Embase, and Google Scholar. The eligibility criteria of this study included the following: the patients were clearly diagnosed as having impacted mandibular third molars; the patients underwent piezosurgery osteotomy, and in the control group rotary osteotomy techniques, for removing impacted third molars; the outcomes of interest include surgery time, trismus, swelling or pain; the studies are randomized controlled trials. We used random-effects models to calculate the difference in the outcomes, and the corresponding 95% confidence interval. We calculated the weighted mean difference if the trials used the same measurement, and a standardized mean difference if otherwise. A total of seven studies met the eligibility criteria and were included in our analysis. Compared with rotary osteotomy, patients undergoing piezosurgery experienced longer surgery time (mean difference 4.13 minutes, 95% confidence interval 2.75–5.52, P < 0.0001). Patients receiving the piezoelectric technique had less swelling at postoperative days 1, 3, 5, and 7 (all Ps ≤0.023). Additionally, there was a trend of less postoperative pain and trismus in the piezosurgery groups. The number of included randomized controlled

  12. Cell surface acid-base properties of the cyanobacterium Synechococcus: Influences of nitrogen source, growth phase and N:P ratios

    NASA Astrophysics Data System (ADS)

    Liu, Yuxia; Alessi, D. S.; Owttrim, G. W.; Kenney, J. P. L.; Zhou, Qixing; Lalonde, S. V.; Konhauser, K. O.

    2016-08-01

    The distribution of many trace metals in the oceans is controlled by biological uptake. Recently, Liu et al. (2015) demonstrated the propensity for a marine cyanobacterium to adsorb cadmium from seawater, suggesting that cell surface reactivity might also play an important role in the cycling of metals in the oceans. However, it remains unclear how variations in cyanobacterial growth rates and nutrient supply might affect the chemical properties of their cellular surfaces. In this study we used potentiometric titrations and Fourier Transform Infrared (FT-IR) spectrometry to profile the key metabolic changes and surface chemical responses of a Synechococcus strain, PCC 7002, during different growth regimes. This included testing various nitrogen (N) to phosphorous (P) ratios (both nitrogen and phosphorous dependent), nitrogen sources (nitrate, ammonium and urea) and growth stages (exponential, stationary, and death phase). FT-IR spectroscopy showed that varying the growth substrates on which Synechococcus cells were cultured resulted in differences in either the type or abundance of cellular exudates produced or a change in the cell wall components. Potentiometric titration data were modeled using three distinct proton binding sites, with resulting pKa values for cells of the various growth conditions in the ranges of 4.96-5.51 (pKa1), 6.67-7.42 (pKa2) and 8.13-9.95 (pKa3). According to previous spectroscopic studies, these pKa ranges are consistent with carboxyl, phosphoryl, and amine groups, respectively. Comparisons between the titration data (for the cell surface) and FT-IR spectra (for the average cellular changes) generally indicate (1) that the nitrogen source is a greater determinant of ligand concentration than growth phase, and (2) that phosphorus limitation has a greater impact on Synechococcus cellular and extracellular properties than does nitrogen limitation. Taken together, these techniques indicate that nutritional quality during cell growth can

  13. The Dependence of Donor:Acceptor Ratio on the Photovoltaic Performances of Blended poly (3-octylthiophene-2,5-diyl) and (6,6)-phenyl C{sub 71} butyric acid methyl ester Bulk Heterojunction Organic Solar Cells

    SciTech Connect

    Fauzia, Vivi; Umar, Akrajas Ali; Salleh, Muhamad Mat; Yahya, Muhammad

    2010-10-24

    Bulk heterojunction organic solar cells using blended poly (3-octylthiophene-2,5-diyl)(P3OT) and (6,6)-phenyl C{sub 71} butyric acid methyl ester (PC{sub 71}BM) have been fabricated. P3OT and PC{sub 71}BM were used as the electron donor (D) and acceptor (A), respectively. Both materials were mixed and dissolved in dichlorobenzene with three different D:A ratios i.e. 1:3, 1:1 and 3:1 (weight) while maintained at the concentration of 2 wt%(26 mg/ml). The blended thin films were sandwiched between the indium tin oxide (ITO) coated glass and the aluminum film. This paper reports the influence of donor:acceptor ratio on the performance of solar cell devices measured by current-voltage measurement both in the dark and under 1.5 AM solar illumination. It was found that all devices showed the photovoltaic effect with poor diode behavior and the donor:acceptor ratio significantly influenced on the performance of bulk heterojunction organic solar cells.

  14. The Dependence of Donor:Acceptor Ratio on the Photovoltaic Performances of Blended poly (3-octylthiophene-2,5-diyl) and (6,6)-phenyl C71 butyric acid methyl ester Bulk Heterojunction Organic Solar Cells

    NASA Astrophysics Data System (ADS)

    Fauzia, Vivi; Umar, Akrajas Ali; Salleh, Muhamad Mat; Yahya, Muhammad

    2010-10-01

    Bulk heterojunction organic solar cells using blended poly (3-octylthiophene-2,5-diyl)(P3OT) and (6,6)-phenyl C71 butyric acid methyl ester (PC71BM) have been fabricated. P3OT and PC71BM were used as the electron donor (D) and acceptor (A), respectively. Both materials were mixed and dissolved in dichlorobenzene with three different D:A ratios i.e. 1:3, 1:1 and 3:1 (weight) while maintained at the concentration of 2 wt% (26 mg/ml). The blended thin films were sandwiched between the indium tin oxide (ITO) coated glass and the aluminum film. This paper reports the influence of donor:acceptor ratio on the performance of solar cell devices measured by current-voltage measurement both in the dark and under 1.5 AM solar illumination. It was found that all devices showed the photovoltaic effect with poor diode behavior and the donor:acceptor ratio significantly influenced on the performance of bulk heterojunction organic solar cells.

  15. Effects of Iron Supplementation With and Without Docosahexaenoic Acid on the Cardiovascular Disease Risk Based on Paraoxonase-1, hs-CRP, and ApoB/ApoA-I Ratio in Women with Iron Deficiency Anemia.

    PubMed

    Shidfar, Farzad; Amani, Samira; Vafa, Mohammadreza; Shekarriz, Ramin; Hosseini, Sharieh; Shidfar, Shahrzad; Eshraghian, Mohammadreza; Mousavi, Seyedeh Neda

    2016-01-01

    Numerous studies have demonstrated that tissue deposition of iron following prolonged high dose of oral supplementation for treatment of iron deficiency anemia (IDA) leads to body iron overload and oxidative stress, which starts the process of atherosclerosis. This study aimed to determine the effect of iron supplementation in combination with docosahexaenoic acid (DHA) on the cardiovascular disease risk based on paraoxonase-1 (PON-1), high-sensitivity C-reactive protein (hs-CRP), and ApoB/ApoA-I ratio in women with IDA. In this randomized controlled trial, 76 women with IDA, aged 15-45 years, were included. The patients were randomly assigned to receive 500 mg of DHA supplement or placebo with an iron tablet, once daily for 12 weeks. The participants were assessed by measurement of the serum iron, ferritin, PON-1, hs-CRP levels, and the ApoB/ApoA-I ratio at the beginning and end of study. Serum hs-CRP decreased in the DHA-supplemented group (p = 0.036), and ApoA-I decreased in the placebo group (p = 0.013). No significant difference was detected for the serum PON-1 concentration and the ApoB/ApoA-I ratio in two groups. Iron supplementation combined with DHA may have favorable effects on serum hs-CRP in women with IDA. PMID:26077874

  16. Exploring metameric variation in human molars: a morphological study using morphometric mapping.

    PubMed

    Morita, Wataru; Morimoto, Naoki; Ohshima, Hayato

    2016-09-01

    Human molars exhibit a type of metameric variation, which is the difference in serially repeated morphology within an organism. Various theories have been proposed to explain how this variation is brought about in the molars. Actualistic data that support the theories, however, are still relatively scarce because of methodological limitations. Here we propose new methods to analyse detailed tooth crown morphologies. We applied morphometric mapping to the enamel-dentine junction of human maxillary molars and examined whether odontogenetic models were adaptable to human maxillary molars. Our results showed that the upper first molar is phenotypically distinct among the maxillary molars. The average shape of the upper first molar is characterized by four well-defined cusps and precipitous surface relief of the occlusal table. On the other hand, upper third molar is characterized by smooth surface relief of the occlusal table and shows greater shape variation and distinct distribution patterns in morphospace. The upper second molar represents an intermediate state between first and third molar. Size-related shape variation was investigated by the allometric vector analysis, and it appeared that human maxillary molars tend to converge toward the shape of the upper first molar as the size increases. Differences between the upper first molar and the upper second and third molar can thus be largely explained as an effect of allometry. Collectively, these results indicate that the observed pattern of metameric variation in human molars is consistent with odontogenetic models of molar row structure (inhibitory cascade model) and molar crown morphology (patterning cascade model). This study shows that morphometric mapping is a useful tool to visualize and quantify the morphological features of teeth, which can provide the basis for a better understanding of tooth evolution linking morphology and development. PMID:27098351

  17. The intake of a hazelnut skin extract improves the plasma lipid profile and reduces the lithocholic/deoxycholic bile acid faecal ratio, a risk factor for colon cancer, in hamsters fed a high-fat diet.

    PubMed

    Caimari, Antoni; Puiggròs, Francesc; Suárez, Manuel; Crescenti, Anna; Laos, Sirle; Ruiz, Juan Antonio; Alonso, Virginia; Moragas, Josep; Del Bas, Josep Maria; Arola, Lluís

    2015-01-15

    The effects on lipid and glucose metabolism of a hazelnut skin extract (FIBEROX™) administrated during 8 weeks (HFD-FBX8w group) or during the last 4 weeks of the study (HFD-FBX4w group) to Golden Syrian hamsters fed a high-fat diet (HFD) for 8 weeks were investigated. FIBEROX™ consumption reversed the increase in total and LDL plasma cholesterol induced by the HFD feeding in both HFD-FBX groups and decreased the circulating levels of free fatty acids and triglycerides in the HFD-FBX4w animals. The higher excretion of bile acids found in the faeces of both groups of hamsters fed the FIBEROX™ suggests that this mechanism is involved in the cholesterol-lowering effects of the extract. Furthermore, FIBEROX™ intake sharply decreased the lithocholic/deoxycholic bile acid faecal ratio, a risk factor for colon cancer, in both HFD-FBX groups. In conclusion, the consumption of FIBEROX™ improves different risk factors associated with cardiovascular disease and colon cancer. PMID:25148970

  18. Enzymatic production of infant milk fat analogs containing palmitic acid: optimization of reactions by response surface methodology.

    PubMed

    Maduko, C O; Akoh, C C; Park, Y W

    2007-05-01

    Infant milk fat analogs resembling human milk fat were synthesized by an enzymatic interesterification between tripalmitin, coconut oil, safflower oil, and soybean oil in hexane. A commercially immobilized 1,3-specific lipase, Lipozyme RM IM, obtained from Rhizomucor miehei was used as a biocatalyst. The effects of substrate molar ratio, reaction time, and incubation temperature on the incorporation of palmitic acid at the sn-2 position of the triacylglycerols were investigated. A central composite design with 5 levels and 3 factors consisting of substrate ratio, reaction temperature, and incubation time was used to model and optimize the reaction conditions using response surface methodology. A quadratic model using multiple regressions was then obtained for the incorporation of palmitic acid at the sn-2 positions of glycerols as the response. The coefficient of determination (R2) value for the model was 0.845. The incorporation of palmitic acid appeared to increase with the decrease in substrate molar ratio and increase in reaction temperature, and optimum incubation time occurred at 18 h. The optimal conditions generated from the model for the targeted 40% palmitic acid incorporation at the sn-2 position were 3 mol/mol, 14.4 h, and 55 degrees C; and 2.8 mol/mol, 19.6 h, and 55 degrees C for substrate ratio (moles of total fatty acid/moles of tripalmitin), time, and temperature, respectively. Infant milk fat containing fatty acid composition and sn-2 fatty acid profile similar to human milk fat was successfully produced. The fat analogs produced under optimal conditions had total and sn-2 positional palmitic acid levels comparable to that of human milk fat. PMID:17430912

  19. Thermal correction to the molar polarizability of a Boltzmann gas

    SciTech Connect

    Jentschura, U. D.; Puchalski, M.; Mohr, P. J.

    2011-12-15

    Metrology in atomic physics has been crucial for a number of advanced determinations of fundamental constants. In addition to very precise frequency measurements, the molar polarizability of an atomic gas has recently also been measured very accurately. Part of the motivation for the measurements is due to ongoing efforts to redefine the International System of Units (SI), for which an accurate value of the Boltzmann constant is needed. Here we calculate the dominant shift of the molar polarizability in an atomic gas due to thermal effects. It is given by the relativistic correction to the dipole interaction, which emerges when the probing electric field is Lorentz transformed into the rest frame of the atoms that undergo thermal motion. While this effect is small when compared to currently available experimental accuracy, the relativistic correction to the dipole interaction is much larger than the thermal shift of the polarizability induced by blackbody radiation.

  20. Thermal correction to the molar polarizability of a Boltzmann gas

    NASA Astrophysics Data System (ADS)

    Jentschura, U. D.; Puchalski, M.; Mohr, P. J.

    2011-12-01

    Metrology in atomic physics has been crucial for a number of advanced determinations of fundamental constants. In addition to very precise frequency measurements, the molar polarizability of an atomic gas has recently also been measured very accurately. Part of the motivation for the measurements is due to ongoing efforts to redefine the International System of Units (SI), for which an accurate value of the Boltzmann constant is needed. Here we calculate the dominant shift of the molar polarizability in an atomic gas due to thermal effects. It is given by the relativistic correction to the dipole interaction, which emerges when the probing electric field is Lorentz transformed into the rest frame of the atoms that undergo thermal motion. While this effect is small when compared to currently available experimental accuracy, the relativistic correction to the dipole interaction is much larger than the thermal shift of the polarizability induced by blackbody radiation.

  1. Ectopic 3rd Molar Tooth in the Maxillary Antrum

    PubMed Central

    Bello, Seidu A.; Oketade, Ifeoluwa O.; Osunde, Otasowie D.

    2014-01-01

    Location of ectopic tooth in a nondentate area like the maxillary antrum is rare. A 17-year-old boy, with one year history of recurrent right facial swelling and radiographic finding of a maxillary third molar tooth located at the posterior wall of the maxillary antrum, is presented. Under endotracheal intubation, the tooth was extracted through a Caldwell-Luc antrostomy approach and patient had an uneventful recovery and has been symptom free for eight months. Ectopic tooth in the maxillary antrum is rare and is commonest with maxillary third molar. It may be symptomless but is more commonly associated with inflammatory symptoms. The treatment of choice is surgical excision which is mostly carried out with Caldwell-Luc approach, even though endoscopic approach is being reported. PMID:25132999

  2. Ectopic 3rd molar tooth in the maxillary antrum.

    PubMed

    Bello, Seidu A; Oketade, Ifeoluwa O; Osunde, Otasowie D

    2014-01-01

    Location of ectopic tooth in a nondentate area like the maxillary antrum is rare. A 17-year-old boy, with one year history of recurrent right facial swelling and radiographic finding of a maxillary third molar tooth located at the posterior wall of the maxillary antrum, is presented. Under endotracheal intubation, the tooth was extracted through a Caldwell-Luc antrostomy approach and patient had an uneventful recovery and has been symptom free for eight months. Ectopic tooth in the maxillary antrum is rare and is commonest with maxillary third molar. It may be symptomless but is more commonly associated with inflammatory symptoms. The treatment of choice is surgical excision which is mostly carried out with Caldwell-Luc approach, even though endoscopic approach is being reported. PMID:25132999

  3. Fate of the molar dental lamina in the monophyodont mouse.

    PubMed

    Dosedělová, Hana; Dumková, Jana; Lesot, Hervé; Glocová, Kristýna; Kunová, Michaela; Tucker, Abigail S; Veselá, Iva; Krejčí, Pavel; Tichý, František; Hampl, Aleš; Buchtová, Marcela

    2015-01-01

    The successional dental lamina (SDL) plays an essential role in the development of replacement teeth in diphyodont and polyphyodont animals. A morphologically similar structure, the rudimental successional dental lamina (RSDL), has been described in monophyodont (only one tooth generation) lizards on the lingual side of the developing functional tooth. This rudimentary lamina regresses, which has been proposed to play a role in preventing the formation of future generations of teeth. A similar rudimentary lingual structure has been reported associated with the first molar in the monophyodont mouse, and we show that this structure is common to all murine molars. Intriguingly, a lingual lamina is also observed on the non-replacing molars of other diphyodont mammals (pig and hedgehog), initially appearing very similar to the successional dental lamina on the replacing teeth. We have analyzed the morphological as well as ultrastructural changes that occur during the development and loss of this molar lamina in the mouse, from its initiation at late embryonic stages to its disappearance at postnatal stages. We show that loss appears to be driven by a reduction in cell proliferation, down-regulation of the progenitor marker Sox2, with only a small number of cells undergoing programmed cell death. The lingual lamina was associated with the dental stalk, a short epithelial connection between the tooth germ and the oral epithelium. The dental stalk remained in contact with the oral epithelium throughout tooth development up to eruption when connective tissue and numerous capillaries progressively invaded the dental stalk. The buccal side of the dental stalk underwent keratinisation and became part of the gingival epithelium, while most of the lingual cells underwent programmed cell death and the tissue directly above the erupting tooth was shed into the oral cavity. PMID:26010446

  4. Five Canalled and Three-Rooted Primary Second Mandibular Molar

    PubMed Central

    Selvakumar, Haridoss; Kavitha, Swaminathan; Bharathan, Rajendran; Varghese, Jacob Sam

    2014-01-01

    A thorough knowledge of root canal anatomy and its variation is necessary for successful completion of root canal procedures. Morphological variations such as additional root canals in human deciduous dentition are rare. A mandibular second primary molar with more than four canals is an interesting example of anatomic variations, especially when three of these canals are located in the distal root. This case shows a rare anatomic configuration and points out the importance of looking for additional canals. PMID:25147744

  5. The maxillary second molar - anatomical variations (case report).

    PubMed

    Beshkenadze, E; Chipashvili, N

    2015-01-01

    To be acquainted with dental anatomical specificity is of great importance for dental endodontic treatment algorithm. The subject of present publication is 2 clinical cases of upper second molars, detailed characterization of, which is considered very important for enrichment of anatomical knowledge about dental anatomical variations. In one case, the reason for admission to the clinic of a 38-year-old woman was complains as of esthetic character as well as functional misbalance (disturbance of chewing function due to the damage of orthopedic construction). The patient indicated to the existence of coronary defects of large size aesthetic discomforts, damage and discolouration of old orthopedic construction (denture) in maxillary right molar area. According to the data obtained after clinical and visiographical examinations, chronic periodontitis of 17 teeth was identified as a result of incomplete endodontic treatment. According to the data obtained after clinical and visiographical examinations, the diagnosis of chronic periodontitis of 17 teeth was identified, tooth 17 with 2 roots and 2 canals. In the second clinical case, the reason for admission to the clinic of a 39-year-old woman was severe pain in the upper right molar area. The patient indicated to the caries on the tooth 17. After completion of proper survey clinical and visiographical examinations, acute pulpitis (K04.00) - with three roots and 4 canals was diagnosed. In both cases after the proper examinations and agreement with the patients a treatment plan envisaging: 17 teeth endodontic treatment, filling of caries defects and their preparation on one hand for orthopedic construction (denture) and on the other hand for restoration of anatomical integrity by light-cured composite, was scheduled. The present study is designed to prevent complications of endodontic treatment of the second molar, to optimize diagnosis and treatment algorithm, once again proving reliable information indicating to the

  6. Extrusion of impacted mandibular second molar using removable appliance

    PubMed Central

    Karthikeyan, M. K.; Prabhakar, Ramachandran; Saravanan, R.; Vikram, N. Raj; Kumar, R. Vinoth; Prasath, R. Eshwara

    2014-01-01

    The purpose of this article is to review the principles of case management of impacted mandibular molars and to illustrate their potential to respond well to treatment. Although the scope of treatment may be influenced by the patient's age, past dental history, severity of impaction, dentoalveolar development, and root form, the case reports demonstrate the inherent potential for good treatment outcome even in the most unfavorable circumstances. PMID:25210378

  7. Five canalled and three-rooted primary second mandibular molar.

    PubMed

    Selvakumar, Haridoss; Kavitha, Swaminathan; Bharathan, Rajendran; Varghese, Jacob Sam

    2014-01-01

    A thorough knowledge of root canal anatomy and its variation is necessary for successful completion of root canal procedures. Morphological variations such as additional root canals in human deciduous dentition are rare. A mandibular second primary molar with more than four canals is an interesting example of anatomic variations, especially when three of these canals are located in the distal root. This case shows a rare anatomic configuration and points out the importance of looking for additional canals. PMID:25147744

  8. Fate of the Molar Dental Lamina in the Monophyodont Mouse

    PubMed Central

    Dosedělová, Hana; Dumková, Jana; Lesot, Hervé; Glocová, Kristýna; Kunová, Michaela; Tucker, Abigail S.; Veselá, Iva; Krejčí, Pavel; Tichý, František; Hampl, Aleš; Buchtová, Marcela

    2015-01-01

    The successional dental lamina (SDL) plays an essential role in the development of replacement teeth in diphyodont and polyphyodont animals. A morphologically similar structure, the rudimental successional dental lamina (RSDL), has been described in monophyodont (only one tooth generation) lizards on the lingual side of the developing functional tooth. This rudimentary lamina regresses, which has been proposed to play a role in preventing the formation of future generations of teeth. A similar rudimentary lingual structure has been reported associated with the first molar in the monophyodont mouse, and we show that this structure is common to all murine molars. Intriguingly, a lingual lamina is also observed on the non-replacing molars of other diphyodont mammals (pig and hedgehog), initially appearing very similar to the successional dental lamina on the replacing teeth. We have analyzed the morphological as well as ultrastructural changes that occur during the development and loss of this molar lamina in the mouse, from its initiation at late embryonic stages to its disappearance at postnatal stages. We show that loss appears to be driven by a reduction in cell proliferation, down-regulation of the progenitor marker Sox2, with only a small number of cells undergoing programmed cell death. The lingual lamina was associated with the dental stalk, a short epithelial connection between the tooth germ and the oral epithelium. The dental stalk remained in contact with the oral epithelium throughout tooth development up to eruption when connective tissue and numerous capillaries progressively invaded the dental stalk. The buccal side of the dental stalk underwent keratinisation and became part of the gingival epithelium, while most of the lingual cells underwent programmed cell death and the tissue directly above the erupting tooth was shed into the oral cavity. PMID:26010446

  9. Spontaneous emergence of overgrown molar teeth in a colony of Prairie voles (Microtus ochrogaster)

    PubMed Central

    Jheon, Andrew H; Prochazkova, Michaela; Sherman, Michael; Manoli, Devanand S; Shah, Nirao M; Carbone, Lawrence; Klein, Ophir

    2015-01-01

    Continuously growing incisors are common to all rodents, which include the Microtus genus of voles. However, unlike many rodents, voles also possess continuously growing molars. Here, we report spontaneous molar defects in a population of Prairie voles (Microtus ochrogaster). We identified bilateral protuberances on the ventral surface of the mandible in several voles in our colony. In some cases, the protuberances broke through the cortical bone. The mandibular molars became exposed and infected, and the maxillary molars entered the cranial vault. Visualisation upon soft tissue removal and microcomputed tomography (microCT) analyses confirmed that the protuberances were caused by the overgrowth of the apical ends of the molar teeth. We speculate that the unrestricted growth of the molars was due to the misregulation of the molar dental stem cell niche. Further study of this molar phenotype may yield additional insight into stem cell regulation and the evolution and development of continuously growing teeth. PMID:25634121

  10. Spontaneous emergence of overgrown molar teeth in a colony of Prairie voles (Microtus ochrogaster).

    PubMed

    Jheon, Andrew H; Prochazkova, Michaela; Sherman, Michael; Manoli, Devanand S; Shah, Nirao M; Carbone, Lawrence; Klein, Ophir

    2015-03-01

    Continuously growing incisors are common to all rodents, which include the Microtus genus of voles. However, unlike many rodents, voles also possess continuously growing molars. Here, we report spontaneous molar defects in a population of Prairie voles (Microtus ochrogaster). We identified bilateral protuberances on the ventral surface of the mandible in several voles in our colony. In some cases, the protuberances broke through the cortical bone. The mandibular molars became exposed and infected, and the maxillary molars entered the cranial vault. Visualisation upon soft tissue removal and microcomputed tomography (microCT) analyses confirmed that the protuberances were caused by the overgrowth of the apical ends of the molar teeth. We speculate that the unrestricted growth of the molars was due to the misregulation of the molar dental stem cell niche. Further study of this molar phenotype may yield additional insight into stem cell regulation and the evolution and development of continuously growing teeth. PMID:25634121

  11. The Use of Narrow Diameter Implants in the Molar Area.

    PubMed

    Saad, M; Assaf, A; Gerges, E

    2016-01-01

    Implant rehabilitations in the posterior jaw are influenced by many factors such as the condition of the remaining teeth, the force factors related to the patient, the quality of the bone, the maintenance of the hygiene, the limited bone height, the type and extent of edentulism, and the nature of the opposing arch. The gold standard is to place a regular diameter implant (>3.7 mm) or a wide one to replace every missing molar. Unfortunately, due to horizontal bone resorption, this option is not possible without lateral bone augmentation. In this situation, narrow diameter implant (NDI < 3.5 mm) could be the alternative to lateral bone augmentation procedures. This paper presents a clinical study where NDIs were used for the replacement of missing molars. They were followed up to 11 years. Special considerations were observed and many parameters were evaluated. NDI could be used to replace missing molar in case of moderate horizontal bone resorption if strict guidelines are respected. Yet, future controlled prospective clinical trials are required to admit their use as scientific evidence. PMID:27293436

  12. Molar tooth carbonates and benthic methane fluxes in Proterozoic oceans

    NASA Astrophysics Data System (ADS)

    Shen, Bing; Dong, Lin; Xiao, Shuhai; Lang, Xianguo; Huang, Kangjun; Peng, Yongbo; Zhou, Chuanming; Ke, Shan; Liu, Pengju

    2016-01-01

    Molar tooth structures are ptygmatically folded and microspar-filled structures common in early- and mid-Proterozoic (~2,500-750 million years ago, Ma) subtidal successions, but extremely rare in rocks <750 Ma. Here, on the basis of Mg and S isotopes, we show that molar tooth structures may have formed within sediments where microbial sulphate reduction and methanogenesis converged. The convergence was driven by the abundant production of methyl sulphides (dimethyl sulphide and methanethiol) in euxinic or H2S-rich seawaters that were widespread in Proterozoic continental margins. In this convergence zone, methyl sulphides served as a non-competitive substrate supporting methane generation and methanethiol inhibited anaerobic oxidation of methane, resulting in the buildup of CH4, formation of degassing cracks in sediments and an increase in the benthic methane flux from sediments. Precipitation of crack-filling microspar was driven by methanogenesis-related alkalinity accumulation. Deep ocean ventilation and oxygenation around 750 Ma brought molar tooth structures to an end.

  13. Determination of partial molar volumes from free energy perturbation theory†

    PubMed Central

    Vilseck, Jonah Z.; Tirado-Rives, Julian

    2016-01-01

    Partial molar volume is an important thermodynamic property that gives insights into molecular size and intermolecular interactions in solution. Theoretical frameworks for determining the partial molar volume (V°) of a solvated molecule generally apply Scaled Particle Theory or Kirkwood–Buff theory. With the current abilities to perform long molecular dynamics and Monte Carlo simulations, more direct methods are gaining popularity, such as computing V° directly as the difference in computed volume from two simulations, one with a solute present and another without. Thermodynamically, V° can also be determined as the pressure derivative of the free energy of solvation in the limit of infinite dilution. Both approaches are considered herein with the use of free energy perturbation (FEP) calculations to compute the necessary free energies of solvation at elevated pressures. Absolute and relative partial molar volumes are computed for benzene and benzene derivatives using the OPLS-AA force field. The mean unsigned error for all molecules is 2.8 cm3 mol−1. The present methodology should find use in many contexts such as the development and testing of force fields for use in computer simulations of organic and biomolecular systems, as a complement to related experimental studies, and to develop a deeper understanding of solute–solvent interactions. PMID:25589343

  14. Molar tooth carbonates and benthic methane fluxes in Proterozoic oceans

    PubMed Central

    Shen, Bing; Dong, Lin; Xiao, Shuhai; Lang, Xianguo; Huang, Kangjun; Peng, Yongbo; Zhou, Chuanming; Ke, Shan; Liu, Pengju

    2016-01-01

    Molar tooth structures are ptygmatically folded and microspar-filled structures common in early- and mid-Proterozoic (∼2,500–750 million years ago, Ma) subtidal successions, but extremely rare in rocks <750 Ma. Here, on the basis of Mg and S isotopes, we show that molar tooth structures may have formed within sediments where microbial sulphate reduction and methanogenesis converged. The convergence was driven by the abundant production of methyl sulphides (dimethyl sulphide and methanethiol) in euxinic or H2S-rich seawaters that were widespread in Proterozoic continental margins. In this convergence zone, methyl sulphides served as a non-competitive substrate supporting methane generation and methanethiol inhibited anaerobic oxidation of methane, resulting in the buildup of CH4, formation of degassing cracks in sediments and an increase in the benthic methane flux from sediments. Precipitation of crack-filling microspar was driven by methanogenesis-related alkalinity accumulation. Deep ocean ventilation and oxygenation around 750 Ma brought molar tooth structures to an end. PMID:26739600

  15. Molar tooth carbonates and benthic methane fluxes in Proterozoic oceans.

    PubMed

    Shen, Bing; Dong, Lin; Xiao, Shuhai; Lang, Xianguo; Huang, Kangjun; Peng, Yongbo; Zhou, Chuanming; Ke, Shan; Liu, Pengju

    2016-01-01

    Molar tooth structures are ptygmatically folded and microspar-filled structures common in early- and mid-Proterozoic (∼2,500-750 million years ago, Ma) subtidal successions, but extremely rare in rocks <750 Ma. Here, on the basis of Mg and S isotopes, we show that molar tooth structures may have formed within sediments where microbial sulphate reduction and methanogenesis converged. The convergence was driven by the abundant production of methyl sulphides (dimethyl sulphide and methanethiol) in euxinic or H2S-rich seawaters that were widespread in Proterozoic continental margins. In this convergence zone, methyl sulphides served as a non-competitive substrate supporting methane generation and methanethiol inhibited anaerobic oxidation of methane, resulting in the buildup of CH4, formation of degassing cracks in sediments and an increase in the benthic methane flux from sediments. Precipitation of crack-filling microspar was driven by methanogenesis-related alkalinity accumulation. Deep ocean ventilation and oxygenation around 750 Ma brought molar tooth structures to an end. PMID:26739600

  16. Variable permanent mandibular first molar: Review of literature

    PubMed Central

    Ballullaya, Srinidhi V; Vemuri, Sayesh; Kumar, Pabbati Ravi

    2013-01-01

    Introduction: The success of root canal therapy depends on the locations of all the canals, thourough debridement and proper sealing. At times the clinicians are challenged with variations in morphology of root canal. This review article attempts to list out all the variations of permanent mandibular first molar published so for in the literature. Materials and Methods: An exhaustive search was undertaken using PUBMED database to identify published literature from 1900 to 2010 relating to the root canal morphology of permanent first molar by using key words. The selected artcles were obtained and reviewed. Results: Total ninty seven articles were selected out of which 50 were original article and forty seven were case reports. The incidence of third canal in mesial root was 0.95% to 15%. The incidence of three rooted mandibular first molar was 3% to 33%. Only ninety cases reported with c-shape canal configuration. Incidence of Taurodintism without congenital disorder was very rare. Conclusion: The root canal treatment requires proper knowlegde of variations in root canal morphology in order to recognise, disinfect and seal all portal of exit. This can be accomplished with proper diagnosis using newer modes, modification in access preparation, use of operating microscope, enhanced methods of disinfecting and sealing of all canals. PMID:23716959

  17. The Use of Narrow Diameter Implants in the Molar Area

    PubMed Central

    Saad, M.; Assaf, A.; Gerges, E.

    2016-01-01

    Implant rehabilitations in the posterior jaw are influenced by many factors such as the condition of the remaining teeth, the force factors related to the patient, the quality of the bone, the maintenance of the hygiene, the limited bone height, the type and extent of edentulism, and the nature of the opposing arch. The gold standard is to place a regular diameter implant (>3.7 mm) or a wide one to replace every missing molar. Unfortunately, due to horizontal bone resorption, this option is not possible without lateral bone augmentation. In this situation, narrow diameter implant (NDI < 3.5 mm) could be the alternative to lateral bone augmentation procedures. This paper presents a clinical study where NDIs were used for the replacement of missing molars. They were followed up to 11 years. Special considerations were observed and many parameters were evaluated. NDI could be used to replace missing molar in case of moderate horizontal bone resorption if strict guidelines are respected. Yet, future controlled prospective clinical trials are required to admit their use as scientific evidence. PMID:27293436

  18. From molecular to molar: a paradigm shift in behavior analysis.

    PubMed Central

    Baum, William M

    2002-01-01

    A paradigm clash is occurring within behavior analysis. In the older paradigm, the molecular view, behavior consists of momentary or discrete responses that constitute instances of classes. Variation in response rate reflects variation in the strength or probability of the response class. The newer paradigm, the molar view, sees behavior as composed of activities that take up varying amounts of time. Whereas the molecular view takes response rate and choice to be "derived" measures and hence abstractions, the molar view takes response rate and choice to be concrete temporally extended behavioral allocations and regards momentary "responses" as abstractions. Research findings that point to variation in tempo, asymmetry in concurrent performance, and paradoxical resistance to change are readily interpretable when seen in the light of reinforcement and stimulus control of extended behavioral allocations or activities. Seen in the light of the ontological distinction between classes and individuals, extended behavioral allocations, like species in evolutionary taxonomy, constitute individuals, entities that change without changing their identity. Seeing allocations as individuals implies that less extended activities constitute parts of larger wholes rather than instances of classes. Both laboratory research and everyday behavior are explained plausibly in the light of concrete extended activities and their nesting. The molecular- view, because it requires discrete responses and contiguous events, relies on hypothetical stimuli and consequences to account for the same phenomena. One may prefer the molar view on grounds of elegance, integrative power, and plausibility. PMID:12144313

  19. Determination of partial molar volumes from free energy perturbation theory.

    PubMed

    Vilseck, Jonah Z; Tirado-Rives, Julian; Jorgensen, William L

    2015-04-01

    Partial molar volume is an important thermodynamic property that gives insights into molecular size and intermolecular interactions in solution. Theoretical frameworks for determining the partial molar volume (V°) of a solvated molecule generally apply Scaled Particle Theory or Kirkwood-Buff theory. With the current abilities to perform long molecular dynamics and Monte Carlo simulations, more direct methods are gaining popularity, such as computing V° directly as the difference in computed volume from two simulations, one with a solute present and another without. Thermodynamically, V° can also be determined as the pressure derivative of the free energy of solvation in the limit of infinite dilution. Both approaches are considered herein with the use of free energy perturbation (FEP) calculations to compute the necessary free energies of solvation at elevated pressures. Absolute and relative partial molar volumes are computed for benzene and benzene derivatives using the OPLS-AA force field. The mean unsigned error for all molecules is 2.8 cm(3) mol(-1). The present methodology should find use in many contexts such as the development and testing of force fields for use in computer simulations of organic and biomolecular systems, as a complement to related experimental studies, and to develop a deeper understanding of solute-solvent interactions. PMID:25589343

  20. Molar Macrowear Reveals Neanderthal Eco-Geographic Dietary Variation

    PubMed Central

    Fiorenza, Luca; Benazzi, Stefano; Tausch, Jeremy; Kullmer, Ottmar; Bromage, Timothy G.; Schrenk, Friedemann

    2011-01-01

    Neanderthal diets are reported to be based mainly on the consumption of large and medium sized herbivores, while the exploitation of other food types including plants has also been demonstrated. Though some studies conclude that early Homo sapiens were active hunters, the analyses of faunal assemblages, stone tool technologies and stable isotopic studies indicate that they exploited broader dietary resources than Neanderthals. Whereas previous studies assume taxon-specific dietary specializations, we suggest here that the diet of both Neanderthals and early Homo sapiens is determined by ecological conditions. We analyzed molar wear patterns using occlusal fingerprint analysis derived from optical 3D topometry. Molar macrowear accumulates during the lifespan of an individual and thus reflects diet over long periods. Neanderthal and early Homo sapiens maxillary molar macrowear indicates strong eco-geographic dietary variation independent of taxonomic affinities. Based on comparisons with modern hunter-gatherer populations with known diets, Neanderthals as well as early Homo sapiens show high dietary variability in Mediterranean evergreen habitats but a more restricted diet in upper latitude steppe/coniferous forest environments, suggesting a significant consumption of high protein meat resources. PMID:21445243

  1. Primate molar crown formation times and life history evolution revisited.

    PubMed

    Macho, G A

    2001-12-01

    Comparative studies have convincingly demonstrated that the pattern and timing of tooth emergence are highly correlated with life-history variables and brain size. Conversely, a firm relationship between molar formation time and life-history variables has not yet been established. It seems counterintuitive that one aspect of dental development should be correlated with life-history variables, whereas the other should not. In order to shed light on this apparent discrepancy this study analyzed all data on primate molar crown formations available in the published literature in relation to life-history variables, brain size, and female body mass. Crown formation times were found to be particularly highly correlated with both female body mass and brain size. Species that depart from the overall brain/body allometry by being relatively large-bodied, e.g., Gorilla gorilla and later Theropithecus oswaldi, also have shorter molar crown formation times than expected. The reverse is not found for species that depart from the overall brain/body allometry due to their larger brains, i.e., Homo sapiens. This finding is interpreted within an evolutionary and ecological framework. Specifically, by focusing on ecological commonalities, a scenario is proposed which may allow predictions to be made about the evolutionary history of other extinct primates also. If confirmed in future studies, crown formation time may again become a powerful tool in evolutionary enquiry. PMID:11748692

  2. Efficacy of Postoperative Prophylactic Antibiotic Therapy in Third Molar Surgery

    PubMed Central

    Reddy B, Praveen

    2014-01-01

    Introduction: Surgical extraction of mandibular third molar is the most frequently performed procedure in oral surgery. This procedure is associated with significant postoperative sequelae such as trismus, swelling, pain and infection. The need of antibiotic therapy during the removal of mandibular third molar has been a contentious issue. Method: This study investigated a regimen by using amoxycillin and metronidazole in one group and without using antibiotics in the other. Both the groups were assessed postoperatively on the 1st, 2nd, 5th, 7th and 10th days by the same observer for post operative mouth opening (interincisal distance), presence of a purulent discharge at the site of surgery, pain and swelling. Result: Overall, no statistically significant difference was seen between both the treatment groups when interincisal distance, pain, swelling and purulent discharge were considered. Conclusion: The results of this study failed to show any advantage which was associated with the routine postoperative use of antibiotics in asymptomatic third molar surgeries. PMID:24995236

  3. Molar Mass and Second Virial Coefficient of Polyethylene Glycol by Vapor Pressure Osmometry

    ERIC Educational Resources Information Center

    Schwinefus, Jeffrey J.; Checkal, Caleb; Saksa, Brian; Baka, Nadia; Modi, Kalpit; Rivera, Carlos

    2015-01-01

    In this laboratory experiment, students determine the number-average molar masses and second virial coefficients of polyethylene glycol (PEG) polymers ranging in molar mass from 200 to 1500 g mol[superscript -1] using vapor pressure osmometry (VPO). Students assess VPO in relation to accurate molar mass calculations of PEG polymers. Additionally,…

  4. Sub-10-Minute Characterization of an Ultrahigh Molar Mass Polymer by Multi-detector Hydrodynamic Chromatography

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molar mass averages, distributions, and architectural information of polymers are routinely obtained using size-exclusion chromatography (SEC). It has previously been shown that ultrahigh molar mass polymers may experience degradation during SEC analysis, leading to inaccurate molar mass averages a...

  5. Proposition of group molar constants for sodium to calculate the partial solubility parameters of sodium salts using the van Krevelen group contribution method.

    PubMed

    Barra, J; Peña, M A; Bustamante, P

    2000-04-01

    The aim of this study is to propose, for the first time, a set of group molar constants for sodium to calculate the partial solubility parameters of sodium salts. The values were estimated using the few experimental partial solubility parameters of acid/sodium salt series available either from the literature (benzoic acid/Na, ibuprofen acid/Na, diclofenac Na) or determined in this work (salicylic acid/Na, p-aminobenzoic acid/Na, diclofenac), the group contribution method of van Krevelen to calculate the partial parameters of the acids, and three reasonable hypothesis. The experimental method used is a modification of the extended Hansen approach based on a regression analysis of the solubility mole fraction of the drug lnX(2) against models including three- or four-partial solubility parameters of a series of pure solvents ranging from non-polar (heptane) to highly polar (water). The modified method combined with the four-parameter model provided the best results for both acids and sodium derivatives. The replacement of the acidic proton by sodium increased the dipolar and basic partial solubility parameters, whereas the dispersion parameter remained unaltered, thus increasing the overall total solubility parameter of the salt. The proposed group molar constants of sodium are consistent with the experimental results as sodium has a relatively low London dispersion molar constant (identical to that of -OH), a very high Keesom dipolar molar constant (identical to that of -NO(2), two times larger than that of -OH), and a very high hydrogen bonding molar constant (identical to that of -OH). The proposed values are: F((Na)d)=270 (J cm(3))(1/2) mol(-1); F((Na)p)=1030 (J cm(3))(1/2) mol(-1); U((Na)h)=17000 J mol(-1). Like the constants for the other groups, the group molar constants proposed for sodium are certainly not the exact values. However, they are believed to be a fair approximation of the impact of sodium on the partial solubility parameters and, therefore, can

  6. Does the Preemptive Use of Oral Nonsteroidal Anti-inflammatory Drugs Reduce Postoperative Pain in Surgical Removal of Third Molars? A Meta-analysis of Randomized Clinical Trials

    PubMed Central

    Costa, Fábio Wildson Gurgel; Esses, Diego Felipe Silveira; de Barros Silva, Paulo Goberlânio; Carvalho, Francisco Samuel Rodrigues; Sá, Carlos Diego Lopes; Albuquerque, Assis Filipe Medeiros; Bezerra, Tácio Pinheiro; Ribeiro, Thyciana Rodrigues; Fonteles, Cristiane Sá Roriz; Soares, Eduardo Costa Studart

    2015-01-01

    The purpose of this study was to investigate the effectiveness of preemptive analgesia with nonsteroidal anti-inflammatory drugs (NSAIDs) in third-molar surgery. A PubMed literature search was conducted for articles restricted to the English language using the following terms (DeCS/MeSH) or combinations: analgesia, third molar, and preemptive. From a total of 704 articles, 6 (n = 420 subjects) were selected. All studies presented a low risk of bias (Cochrane criteria) but exhibited high heterogeneity of methods. Two studies were excluded from the meta-analysis because they did not have adequate numeric values (dichotomous data) for the calculations. Preemptive analgesia showed no significant benefit (n = 298, P = .2227, odds ratio: 2.30, 0.60–8.73) in reducing postoperative pain after removal of lower impacted third molars. However, there was a probable direct relationship between the effectiveness of NSAIDs in preemptive analgesia for removal of third molars and its selectivity for the cyclooxygenase-2 (COX-2). Preemptive analgesia did not have a significant effect in reducing postoperative pain after removal of lower impacted third molars. More homogeneous and well-delineated clinical studies are necessary to determine a possible association between NSAIDs' selectivity for COX-2 and treatment effectiveness. PMID:26061574

  7. Does the Preemptive Use of Oral Nonsteroidal Anti-inflammatory Drugs Reduce Postoperative Pain in Surgical Removal of Third Molars? A Meta-analysis of Randomized Clinical Trials.

    PubMed

    Costa, Fábio Wildson Gurgel; Esses, Diego Felipe Silveira; de Barros Silva, Paulo Goberlânio; Carvalho, Francisco Samuel Rodrigues; Sá, Carlos Diego Lopes; Albuquerque, Assis Filipe Medeiros; Bezerra, Tácio Pinheiro; Ribeiro, Thyciana Rodrigues; Sá Roriz Fonteles, Cristiane; Soares, Eduardo Costa Studart

    2015-01-01

    The purpose of this study was to investigate the effectiveness of preemptive analgesia with nonsteroidal anti-inflammatory drugs (NSAIDs) in third-molar surgery. A PubMed literature search was conducted for articles restricted to the English language using the following terms (DeCS/MeSH) or combinations: analgesia, third molar, and preemptive. From a total of 704 articles, 6 (n=420 subjects) were selected. All studies presented a low risk of bias (Cochrane criteria) but exhibited high heterogeneity of methods. Two studies were excluded from the meta-analysis because they did not have adequate numeric values (dichotomous data) for the calculations. Preemptive analgesia showed no significant benefit (n=298, P=.2227, odds ratio: 2.30, 0.60-8.73) in reducing postoperative pain after removal of lower impacted third molars. However, there was a probable direct relationship between the effectiveness of NSAIDs in preemptive analgesia for removal of third molars and its selectivity for the cyclooxygenase-2 (COX-2). Preemptive analgesia did not have a significant effect in reducing postoperative pain after removal of lower impacted third molars. More homogeneous and well-delineated clinical studies are necessary to determine a possible association between NSAIDs' selectivity for COX-2 and treatment effectiveness. PMID:26061574

  8. Coumarin-bearing triarylamine sensitizers with high molar extinction coefficient for dye-sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Zhong, Changjian; Gao, Jianrong; Cui, Yanhong; Li, Ting; Han, Liang

    2015-01-01

    Coumarin unit is introduced into triarylamine and three organic sensitizers are designed and synthesized with triarylamine bearing coumarin moiety as the electron donor, conjugated system containing thiophene unit as the π-bridge, and cyanoacetic acid moiety as the electron acceptor. The light-harvesting capabilities and photovoltaic performance of these dyes are investigated systematically with the comparison of different π-bridges. High molar extinction coefficients are observed in these triarylamine dyes and the photocurrent and photovoltage are increased with the introduction of another thiophene or benzene. Optimal photovoltaic performance (η = 6.24%, Voc = 690 mV, Jsc = 14.33 mA cm-2, and ff = 0.63) is observed in the DSSC based on dye with thiophene-phenyl unit as the π-conjugated bridge under 100 mW cm-2 simulated AM 1.5 G solar irradiation.

  9. Fed-batch production of poly-3-hydroxydecanoate from decanoic acid.

    PubMed

    Gao, Jie; Ramsay, Juliana A; Ramsay, Bruce A

    2016-01-20

    Decanoic acid is an ideal substrate for the synthesis of medium-chain-length poly-3-hydroxyalkanoate (MCL-PHA), but its use for this purpose has only previously been studied in shake-flasks likely due to its surfactant properties, low aqueous solubility and high melting temperature. A fed-batch fermentation process was developed for the production of MCL-PHA from decanoic acid using Pseudomonas putida KT2440. Decanoic acid was kept in liquid form by heating or by mixing with acetic acid to prevent crystallization. Different ratios of decanoic acid:acetic acid:glucose (DA:AA:G) were fed to produce a specific growth rate of 0.15 h(-1). This method produced a maximum of 39 g L(-1) dry biomass containing 67% MCL-PHA when the DA:AA:G ratio was 5:1:4. However, a declining growth rate occurred in the late stage of fermentation, resulting in decanoic acid accumulation in the bioreactor leading to foaming. The duration of MCL-PHA production was extended by shifting from exponential to linear feeding before accumulation of decanoic acid. This resulted in 75 g L(-1) biomass containing 74% PHA and an overall PHA productivity of 1.16 g L(-1)h(-1) with the production of each gram of PHA requiring only 1.16 g of decanoic acid. The final PHA composition (on a molar basis) was 78% 3-hydroxydecanoate, 11% 3-hydroxyoctanoate and 11% 3-hydroxyhexanoate. PMID:26689481

  10. Isotopic Ratio, Isotonic Ratio, Isobaric Ratio and Shannon Information Uncertainty

    NASA Astrophysics Data System (ADS)

    Ma, Chun-Wang; Wei, Hui-Ling

    2014-11-01

    The isoscaling and the isobaric yield ratio difference (IBD) probes, both of which are constructed by yield ratio of fragment, provide cancelation of parameters. The information entropy theory is introduced to explain the physical meaning of the isoscaling and IBD probes. The similarity between the isoscaling and IBD results is found, i.e., the information uncertainty determined by the IBD method equals to β - α determined by the isoscaling (α (β) is the parameter fitted from the isotopic (isotonic) yield ratio).

  11. Sialyltransferase and Neuraminidase Levels/Ratios and Sialic Acid Levels in Peripheral Blood B Cells Correlate with Measures of Disease Activity in Patients with Systemic Lupus Erythematosus and Rheumatoid Arthritis: A Pilot Study

    PubMed Central

    Liou, Lieh-bang; Huang, Che-ching

    2016-01-01

    Objective We attempted to determine whether the level of enzymes sialyltransferase (ST) and neuraminidase (Neu) and sialic acid (SIA) in patients with systemic lupus erythematosus (SLE) correlates with the SLE Disease Activity Index (SLEDAI) and in patients with rheumatoid arthritis (RA) correlates with the Disease Activity Score28 (DAS28). Methods We examined cell-surface levels of ST6Gal-1, Neu1, ST3Gal-1, Neu3, α-2,6-SIA, and α-2,3-SIA by using fluorescent anti-enzyme antibodies, fluorescent-conjugated Sambucus nigra lectin, and fluorescent-conjugated Maackia amurensis lectin on blood cells in SLE and RA patients and assessed correlations of these levels with SLEDAI and with DAS28. Areas under the curve (AUC) were calculated for different variables against SLEDAI. Results The B-cell ST3Gal-1/Neu3 ratio positively correlated with SLEDAI scores (ρ = 0.409 and P = 0.002, statistically significant after Bonferroni’ correction for multiple analyses.). It was supported by the inverse correlation of B-cell Neu3 levels with SLEDAI scores (ρ = −0.264, P = 0.048). The B-cell ST3Gal-1/Neu3 ratio against SLEDAI yielded an AUC of 0.689, which was comparable to that of anti-dsDNA levels at 0.635. In contrast, both ST3Gal-1 and Neu3 levels of RA B cells (r = 0.376, P = 0.013; r = 0.425, P = 0.005, respectively) correlated positively with high disease-activity DAS28 scores. Conclusion B-cell ST3Gal-1/Neu3 ratios in SLE and B-cell ST3Gal-1 and Neu3 levels in RA with high disease-activity DAS28 scores correlated with disease activity measures and may be useful in monitoring disease activities. PMID:26981635

  12. Asymmetrical flow field-flow fractionation coupled with multi-angle light scattering and refractive index detections for characterization of ultra-high molar mass poly(acrylamide) flocculants.

    PubMed

    Leeman, Mats; Islam, Mohammad T; Haseltine, William G

    2007-11-23

    The molar mass distributions of ultra-high molar mass polyacrylamide-based flocculants were measured using asymmetrical flow field-flow fractionation (AFFFF) coupled with multi-angle light scattering and refractive index detectors. The mass load onto the separation channel was found to be critical in obtaining a good size separation. The detailed investigation with ultra-high molar mass polyacrylamides found that the injected amount should be ratio (S/N) of the detector responses was low. To overcome this limitation and thereby to obtain more accurate and precise molar mass and radius information, each sample was injected 10 times and the resulting signals were averaged before calculating the molar mass and radius. In addition, the channel was equipped with a slotted outlet to increase the concentration of sample passing through the detectors. After implementing the above strategies, it was possible to perform separation of polymers having molar mass and size as high as 10(8)gmol(-1) and root-mean-square radius of approximately 250nm, respectively. The resulting weight-average molar mass of the highest MW sample was in excess of 18x10(6)gmol(-1). PMID:17961584

  13. Mandibular third molar development after mantle radiation in long-term survivors of childhood Hodgkin's disease

    SciTech Connect

    McGinnis, J.P. Jr.; Hopkins, K.P.; Thompson, E.I.; Hustu, H.O.

    1987-05-01

    Sequential panoramic radiographs were assessed for mandibular third molar development in 47 long-term survivors of childhood Hodgkin's disease after treatment with 37 Gy mantle field radiation. To make a comparison, panoramic radiographs of 149 healthy, nonirradiated children were reviewed for the presence of mandibular third molars. In children between the ages of 7 and 12 years, bilateral agenesis of mandibular third molars was more frequent in patients who had been treated with mantle radiation than in nonirradiated patients. Unilateral agenesis, crown hypoplasia, and root growth impairment of mandibular third molars were also found. Similar, apparent, radiation-induced developmental anomalies were noted in maxillary third molars of the irradiated patients.

  14. The partial molar sound speed of TiO2 in sodium silicate melts: Evidence for an exceptionally compressible component

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Ai, Y.; Lange, R. A.

    2005-12-01

    Longitudinal acoustic velocities were measured at one bar by an ultrasonic frequency sweep acoustic interferometer for ten Na2O-TiO2-SiO2 (NTS) liquids for which previous density and thermal expansion measurements were made (Liu and Lange, 2001). This previous study showed that the partial molar volume of the TiO2 component varied systematically with composition and reflected changes in the average coordination of Ti4+ from values of ~4.6 to ~5.4. Sound speed data were collected at frequencies of 4.5, 5, and 6 MHz between 1233 and 1896 K; in all cases, the sound speeds decrease with increasing temperature. Six of the liquids share a similar (~25 mol%) TiO2 concentration, so that the effect of varying Na:Si ratio on the partial molar sound speed of the TiO2 component can be evaluated. The results for these ten NTS liquids were combined with sound speed data on Na2O-SiO2 liquids from the literature to derive the partial molar sound speed of the TiO2 component in these liquids. The results show that, at 1573 K, it is inversely correlated with SiO2 concentration, from values as low as 571±56 m/s to those as high as 1235±54 m/s, a variation of more than 100%. Fitted values for the partial molar sound speeds of the SiO2 and Na2O components at 1573 K are constants at 2538±52 and 2713±52 m/s, respectively. When the sound speed data are combined with density data to calculate melt compressibility, the results show that the TiO2 component is 3-15 more compressible than either the Na2O or SiO2 component. The partial molar compressibility of the TiO2 component is also strongly correlated to its partial molar thermal expansivity. It is shown that the TiO2 component is most compressible and most expansive when the average Ti4+ coordination in these sodium silicate liquids is near five, which strongly suggests that the abundance of five-coordinated Ti4+ enhances topological mechanisms of both compression and thermal expansion.

  15. REDUCTION OF PLUTONIUM VALUES IN AN ACIDIC AQUEOUS SOLUTION WITH FORMALDEHYDE

    DOEpatents

    Olson, C.M.

    1959-06-01

    A method is given for reducing Pu to the tetravalent state and lowering the high acidity of dissolver solutions containing U and Pu. Formaldehyde is added to the HNO/sub 3/ solution of U and Pu to effect a formaldehyde to HNO/sub 3/ molar ratio of 0.375:1 to 1.5:1. The Pu can then be removed from the solution by carrier precipitation using BiPO/sub 4/ or by ion exchange. (T.R.H.)

  16. [Lipase-catalyzed production of biodiesel from high acid value waste oil with ultrasonic assistant].

    PubMed

    Wang, Jian-Xun; Huang, Qing-De; Huang, Feng-Hong; Wang, Jiang-Wei; Huang, Qin-Jie

    2007-11-01

    Biodiesel fuel produced with the enzyme-catalyzed esterification and transesterification of high acid value waste oil through ultrasonic assistant was explored. Propyl oleate, biodiesel, converted from high acid value waste oil and 1-proponal catalyzed with immobilized lipases from Candida antarctica and Aspergillus oryzae in conditions of ultrasonic assistant. Commercial immobilized lipase Novozym 435 from C. antarctica was used as biocatalyst catalyzing high acid value waste oil and 1-proponal esterification and transesterification to propyl oleate under the ultrasonic assistant conditions and different conditions such as lipases amounts, initiatory molar ratio of propanol to oil, frequency of ultrasonic and power of ultrasonic were investigated and optimized. It is revealed that the enzymatic activity of Novozym435 is enhanced and, in particular, enzyme-catalyzed transesterification activity is enhanced obviously under the ultrasonic assistant conditions. Low frequency and mild energy ultrasonic is a key factor for enhancing enzymatic activity, emulsifying oil-propanol system and accelerating the speed of produce diffusing in the system. Under the optimal ultrasonic assistant reaction conditions, such as Novozym435 amounts 8% by oil quantity, initiatory molar ratio of propanol to oil 3:1, frequency of ultrasonic 28 KHz, power of ultrasonic 100 W and temperature of water batch 40-45 degrees C, the conversion ratio to propyl oleate reached to 94.86% in 50 mins in comparison with the highest conversion ratio to propyl oleate 84.43% under the conventional mechanical agitation conditions. Furthermore, it is demonstrated that various short chain linear and branched alcohols (C1-C5) show high conversion ratio to fatty acid alkyl esters (biodiesel) under the optimal ultrasonic assistant reaction conditions. On the other hand, ultrasonic energy is propitious to reduce the adsorption of product propyl oleate, by-product glycerol and other emplastics in system on the

  17. Compensation trends of the angulation of first molars: retrospective study of 1 403 malocclusion cases

    PubMed Central

    Su, Hong; Han, Bing; Li, Sa; Na, Bin; Ma, Wen; Xu, Tian-Min

    2014-01-01

    We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1 403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First, angulation of the upper first molar varied significantly with age and tipped most distally in cases aged <12 years and least distally in cases aged >16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability. PMID:24699185

  18. Patterning by heritage in mouse molar row development

    PubMed Central

    Prochazka, Jan; Pantalacci, Sophie; Churava, Svatava; Rothova, Michaela; Lambert, Anne; Lesot, Hervé; Klein, Ophir; Peterka, Miroslav; Laudet, Vincent; Peterkova, Renata

    2010-01-01

    It is known from paleontology studies that two premolars have been lost during mouse evolution. During mouse mandible development, two bud-like structures transiently form that may represent rudimentary precursors of the lost premolars. However, the interpretation of these structures and their significance for mouse molar development are highly controversial because of a lack of molecular data. Here, we searched for typical tooth signaling centers in these two bud-like structures, and followed their fate using molecular markers, 3D reconstructions, and lineage tracing in vitro. Transient signaling centers were indeed found to be located at the tips of both the anterior and posterior rudimentary buds. These centers expressed a similar set of molecular markers as the “primary enamel knot” (pEK), the signaling center of the first molar (M1). These two transient signaling centers were sequentially patterned before and anterior to the M1 pEK. We also determined the dynamics of the M1 pEK, which, slightly later during development, spread up to the field formerly occupied by the posterior transient signaling center. It can be concluded that two rudimentary tooth buds initiate the sequential development of the mouse molars and these have previously been mistaken for early stages of M1 development. Although neither rudiment progresses to form an adult tooth, the posterior one merges with the adjacent M1, which may explain the anterior enlargement of the M1 during mouse family evolution. This study highlights how rudiments of lost structures can stay integrated and participate in morphogenesis of functional organs and help in understanding their evolution, as Darwin suspected long ago. PMID:20709958

  19. Patterning by heritage in mouse molar row development.

    PubMed

    Prochazka, Jan; Pantalacci, Sophie; Churava, Svatava; Rothova, Michaela; Lambert, Anne; Lesot, Hervé; Klein, Ophir; Peterka, Miroslav; Laudet, Vincent; Peterkova, Renata

    2010-08-31

    It is known from paleontology studies that two premolars have been lost during mouse evolution. During mouse mandible development, two bud-like structures transiently form that may represent rudimentary precursors of the lost premolars. However, the interpretation of these structures and their significance for mouse molar development are highly controversial because of a lack of molecular data. Here, we searched for typical tooth signaling centers in these two bud-like structures, and followed their fate using molecular markers, 3D reconstructions, and lineage tracing in vitro. Transient signaling centers were indeed found to be located at the tips of both the anterior and posterior rudimentary buds. These centers expressed a similar set of molecular markers as the "primary enamel knot" (pEK), the signaling center of the first molar (M1). These two transient signaling centers were sequentially patterned before and anterior to the M1 pEK. We also determined the dynamics of the M1 pEK, which, slightly later during development, spread up to the field formerly occupied by the posterior transient signaling center. It can be concluded that two rudimentary tooth buds initiate the sequential development of the mouse molars and these have previously been mistaken for early stages of M1 development. Although neither rudiment progresses to form an adult tooth, the posterior one merges with the adjacent M1, which may explain the anterior enlargement of the M1 during mouse family evolution. This study highlights how rudiments of lost structures can stay integrated and participate in morphogenesis of functional organs and help in understanding their evolution, as Darwin suspected long ago. PMID:20709958

  20. Cameriere's third molar maturity index in assessing age of majority.

    PubMed

    Galić, Ivan; Lauc, Tomislav; Brkić, Hrvoje; Vodanović, Marin; Galić, Elizabeta; Biazevic, Maria Gabriela Haye; Brakus, Ivan; Badrov, Jozo; Cameriere, Roberto

    2015-07-01

    Estimation of chronological age of an individual is one of the main challenges in forensic science. Legally to be able to treat a person as a minor or an adult, it is necessary to determine whether their age of majority (if they are older or younger than 18, in most countries). Methods for estimating age are especially important when an individual in question lacks personal documents or other means of identification. As the dental age differs in various populations, the aim of this study was to evaluate applicability of third molar method for assessing age of majority in Croatia. Cameriere's third molar maturity index (I3M) value of 0.08, measured by the open apices of the teeth, was verified in sample of 1336 panoramic images aged between 14 and 23 years. Chronological age gradually decreased as I3M increased in both genders. Males showed statistically significant advanced maturation when I3M was between 0.0 and 0.3 value. The results indicate that the sensitivity of the test for 0.08 value was 84.3% (95%CI 80.6%, 87.5%) for females and 91.2% (95%CI 88.7%, 93.1) for males. Specificity was 95.4% (95%CI 92.5%, 97.5%) and 91.9% (95%CI 88.8%, 94.3%). The proportions of accurately classified males were 88.8% and that of females 91.5%. The estimated post-test probabilities, of individuals, in other word the probability that a Croatian individual with an I3M<0.08 is 18 years or older is 94.5% for females, and 96.5% for males. With high accuracy, the third molar maturity index should be used as a determinant of the age of majority in Croatia. PMID:26013667

  1. Restoration of Endodontically Treated Molars Using All Ceramic Endocrowns

    PubMed Central

    Carlos, Roopak Bose; Thomas Nainan, Mohan; Pradhan, Shamina; Roshni Sharma; Benjamin, Shiny; Rose, Rajani

    2013-01-01

    Clinical success of endodontically treated posterior teeth is determined by the postendodontic restoration. Several options have been proposed to restore endodontically treated teeth. Endocrowns represent a conservative and esthetic restorative alternative to full coverage crowns. The preparation consists of a circular equigingival butt-joint margin and central retention cavity into the entire pulp chamber constructing both the crown and the core as a single unit. The case reports discussed here are moderately damaged endodontically treated molars restored using all ceramic endocrowns fabricated using two different systems, namely, CAD/CAM and pressed ceramic. PMID:24455318

  2. Histological evaluation of mandibular third molar roots retrieved after coronectomy.

    PubMed

    Patel, Vinod; Sproat, Chris; Kwok, Jerry; Beneng, Kiran; Thavaraj, Selvam; McGurk, Mark

    2014-05-01

    There is a resurgence of interest in coronectomy for the management of mandibular third molars because it has a low risk of injury to the inferior dental nerve. However, there is concern that the root that is left in place will eventually become a source of infection. We describe the histological evaluation of 26 consecutive symptomatic coronectomy roots in 21 patients. All roots had vital tissue in the pulp chamber and there was no evidence of periradicular inflammation. Persistent postoperative symptoms related predominantly to inflammation of the soft tissue, which was caused by partially erupted roots or failure of the socket to heal. PMID:24684971

  3. Why, what and how: caries control for erupting molars.

    PubMed

    Rogers, Helen J; Morgan, Annie G; Batley, Haris; Deery, Chris

    2015-03-01

    This article aims to update the practitioner on the various techniques and interventions available to prevent or control caries during this high-risk period. The evidence to support provision of toothbrushing advice, placement of fissure sealants and fluoride varnish application is considered, along with more novel methods. An evidence-based protocol is suggested to help the practitioner determine when further intervention is required and what action to undertake. Clinical Relevance: This article aims to reinforce the need for rigorous caries prevention in an erupting permanent molar and provides an update on the evidence behind a range of clinical techniques used for this purpose. PMID:26058229

  4. The topography of the furcation entrance in Chinese molars. Furcation entrance dimensions.

    PubMed

    Hou, G L; Chen, S F; Wu, Y M; Tsai, C C

    1994-08-01

    The purpose of the present study was to document the furcation entrance dimensions (FEDs) of the maxillary and mandibular 1st and 2nd molars and relate them to the choice of periodontal therapy. Study samples consisted of 89 maxillary molars (49 1st and 40 2nd molars) and 93 mandibular molars (50 1st and 43 2nd molars). All the FEDs of the molars were examined and measured under a stereomicroscope at 2.5 x equipped with a Bioscan OPTIMAS Image Analyzer (BOIA). The results may be summarized as follows. (1) The mean FEDs in the buccal, distal and mesial furcations of maxillary 1st and 2nd molars were 0.74 mm, 0.99 mm and 1.04 mm in the 1st molars, and 0.63 mm, 0.67 mm, 0.90 mm in the 2nd molars, respectively. In the buccal and lingual furcations of mandibular 1st and 2nd molars, they measured 0.88 mm and 0.81 mm, and 0.73 mm and 0.71 mm, respectively. (2) The %s of FEDs of 0.56 mm or less (the tip width of a Cavitron tip being 0.56 mm) in the buccal, distal and mesial furcations of maxillary 1st and 2nd molars, accounted for 32%, 8% and 6% of 1st molars, and 40%, 40% and 18% of 2nd molars. In the buccal and lingual areas of mandibular 1st and 2nd molars, they accounted for 16% and 26%, and 35% and 33% of the furcations, respectively.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7929856

  5. Replantation of a maxillary second molar after removal of a third molar with a dentigerous cyst: Case report and 12-month follow-up

    PubMed Central

    Peñarrocha-Diago, María A.; Peñarrocha-Oltra, David; Peñarrocha-Diago, Miguel

    2014-01-01

    The aim of this study was to describe the replantation of a maxillary second right molar, which had been removed for surgical reasons in order to remove a dentigerous cyst associated with the adjacent third molar, and the case’s 12-month follow-up. A 51-year-old man presented swelling in the right maxillary area. Radiographic examination showed a large radiolucency in close proximity to the third molar, suggesting a follicular cyst. The third molar was extracted and the cyst underwent curettage. The second molar had to be extracted to enable complete removal of the cyst and to achieve primary closure of the wound, which would have been impossible without repositioning the molar. With this objective, extraoral endodontic treatment was performed, the root-end was resected and prepared with ultrasonic retrotips, and root-end filling was accomplished with MTA before the molar was replanted. At the 12-month follow-up, the tooth showed no clinical signs or symptoms, probing depth was no greater than 3 mm and radiographic examination showed no evidence of root resorption or periapical lesion. Key words:Replantation, maxillary molar, follicular cyst, dentigerous cyst. PMID:24790721

  6. Green acetylation of solketal and glycerol formal by heterogeneous acid catalysts to form a biodiesel fuel additive.

    PubMed

    Dodson, Jennifer R; Leite, Thays d C M; Pontes, Nathália S; Peres Pinto, Bianca; Mota, Claudio J A

    2014-09-01

    A glut of glycerol has formed from the increased production of biodiesel, with the potential to integrate the supply chain by using glycerol additives to improve biodiesel properties. Acetylated acetals show interesting cold flow and viscosity effects. Herein, a solventless heterogeneously catalyzed process for the acetylation of both solketal and glycerol formal to new products is demonstrated. The process is optimized by studying the effect of acetylating reagent (acetic acid and acetic anhydride), reagent molar ratios, and a variety of commercial solid acid catalysts (Amberlyst-15, zeolite Beta, K-10 Montmorillonite, and niobium phosphate) on the conversion and selectivities. High conversions (72-95%) and selectivities (86-99%) to the desired products results from using acetic anhydride as the acetylation reagent and a 1:1 molar ratio with all catalysts. Overall, there is a complex interplay between the solid catalyst, reagent ratio, and acetylating agent on the conversion, selectivities, and byproducts formed. The variations are discussed and explained in terms of reactivity, thermodynamics, and reaction mechanisms. An alternative and efficient approach to the formation of 100% triacetin involves the ring-opening, acid-catalyzed acetylation from solketal or glycerol formal with excesses of acetic anhydride. PMID:25045049

  7. Preparation and characterization of ambazone salt with nicotinic acid

    NASA Astrophysics Data System (ADS)

    Kacsó, I.; Muresan-Pop, M.; Borodi, Gh.; Bratu, I.

    2012-02-01

    Salt formation is a good method of increasing solubility, dissolution rate and consequently the bioavailability of poor soluble acidic or basic drugs. The aim of this study was to obtain and to investigate the structural properties of the compound that was obtained by solvent drop grinding method at room temperature starting from the 1:1 molar ratios of ambazone (AMB) and nicotinic acid (NA). The obtained compound (AMB•NA) was investigated by thermal analysis (DSC, TG-DTA), X-ray powder diffraction (PXRD) and infrared spectroscopy (FTIR). The difference between the patterns of AMB•NA and of the starting compounds evidenced the formation of a salt. Using X-ray powder diffraction data, the lattice parameters were determined. The thermal and FTIR measurements on the pure compounds and on the (1:1) grinding mixture of AMB with NA confirm the salt formation.

  8. Synthesis, Spectral, and In Vitro Antibacterial Studies of Organosilicon(IV) Complexes with Schiff Bases Derived from Amino Acids

    PubMed Central

    Singh, Har Lal; Singh, Jangbhadur; Mukherjee, A.

    2013-01-01

    The present work stems from our interest in the synthesis, characterization, and antibacterial evaluation of organosilicon(IV) complexes of a class of amino-acid-based Schiff base which have been prepared by the interaction of ethoxytrimethylsilane with the Schiff bases (N OH) in 1 : 1 molar ratio. These complexes have been characterized by elemental analysis, molar conductance, and spectroscopic studies including electronic IR and NMR (1H, 13C, and 29Si) spectroscopy. The analytical and spectral data suggest trigonal bipyramidal geometry around the silicon atom in the resulting complexes. The ligands and their organosilicon complexes have also been evaluated for in vitro antimicrobial activity against bacteria (Bacillus cereus, Nocardia spp., E. aerogenes, Escherichia coli, Klebsiella spp., and Staphylococcus spp.). The complexes were found to be more potent as compared to the ligands. PMID:23983671

  9. Performance of the wet oxidation unit of the HPLC isotope ratio mass spectrometry system for halogenated compounds.

    PubMed

    Gilevska, Tetyana; Gehre, Matthias; Richnow, Hans Hermann

    2014-08-01

    The performance of liquid chromatography-isotope ratio mass spectrometry (LC-IRMS) for polar halogenated compounds was evaluated. Oxidation capacity of the system was tested with halogenated acetic acids and halogenated aromatic compounds. Acetic acid (AA) was selected as a reference compound for complete oxidation and compared on the molar basis to the oxidation of other analytes. The isotope values were proofed with calibrated δ(13)C values obtained with an elemental analyzer (EA). Correct isotope values were obtained for mono- and dichlorinated, fluorinated, and tribrominated acetic acids and also for aniline, phenol, benzene, bromobenzene, chlorobenzene, 1,2-dichlorobenzene, 2,4,6-trichlorophenol, pentafluorophenol, and nitrobenzene. Incomplete oxidation of trichloroacetic acid (TCA) and trifluoroacetic acid (TFA) resulted in lower recovery compared to AA (37% and 24%, respectively) and in isotopic shift compared to values obtained with EA (TCA Δδ(13)C(EA/LC-IRMS) = 8.8